<%BANNER%>

Evaluation of a Single Incision Laparoscopic Surgery Port for Feline Laparoscopic and Laparoscopic Assisted Surgery

Permanent Link: http://ufdc.ufl.edu/UFE0045528/00001

Material Information

Title: Evaluation of a Single Incision Laparoscopic Surgery Port for Feline Laparoscopic and Laparoscopic Assisted Surgery
Physical Description: 1 online resource (75 p.)
Language: english
Creator: Coisman, James G
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2013

Subjects

Subjects / Keywords: feline -- invasive -- laparoscopy -- minimally -- surgery
Veterinary Medicine -- Dissertations, Academic -- UF
Genre: Veterinary Medical Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Laparoscopic surgery is a well established minimally invasive surgical modality in cats and dogs.  Currently, more emphasis is being placed on reducing the number of incisions required for laparoscopic procedures in order to reduce pain and morbidity associated with multiple incisions. To date, no evaluations of Single Incision Laparoscopic Surgery (SILS) ports have been reported in cats. The purpose of this study was to show that the use of these ports is both economically feasible and clinically applicable. Three SILS (TM) ports were utilized in the in vitro evaluation. The negative control port underwent decontamination and ethylene oxide sterilization without bacterial inoculation, the positive control port underwent bacterial inoculation without decontamination sterilization and the treatment port underwent bacterial inoculation followed by decontamination and ethylene oxide sterilization. Five testing cycles were conducted; during each time, a sample of the foam portion of each port was obtained and bacteriologic culture was performed. None of the treated port samples had positive culture results. All 5 positive control port samples had positive culture results. One negative control port sample grew a spore-forming Bacillus sp organism which was thought to be an environmental contaminant. In vivo evaluation of the port was performed by comparing three methods of laparoscopic sterilization in twenty-four healthy, female, domestic cats. Cats were randomly assigned to one of three groups: single incision laparoscopic ovariectomy-LigaSure (SILOVE-LS (n=8)), single incision laparoscopic ovariectomy-extracorporeal suture (SILOVE-ECS (n=8)) or open ovariectomy (open-OVE (n=8)). Single-incision laparoscopic ovariectomy was successful in (n=8) SILOVE-LS cats and (n=5) SILOVE-ECS cats. Surgical time was longer and more complications occurred in the SILOVE-ECS group. Post-operative pain was not different between groups. Our study demonstrates that decontamination and sterilization was effective for eliminating bacterial viability in a contaminated SILS (TM) port model. Also, ovariectomy performed with the SILS (TM) port is clinically applicable and safe in cats. Further in vitro and clinical testing is warranted to identify potential complications of reuse of this device, such as infection or port malfunction, before routine reuse of the port can be recommended.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by James G Coisman.
Thesis: Thesis (M.S.)--University of Florida, 2013.
Local: Adviser: Case, Joseph Bradly.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-05-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2013
System ID: UFE0045528:00001

Permanent Link: http://ufdc.ufl.edu/UFE0045528/00001

Material Information

Title: Evaluation of a Single Incision Laparoscopic Surgery Port for Feline Laparoscopic and Laparoscopic Assisted Surgery
Physical Description: 1 online resource (75 p.)
Language: english
Creator: Coisman, James G
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2013

Subjects

Subjects / Keywords: feline -- invasive -- laparoscopy -- minimally -- surgery
Veterinary Medicine -- Dissertations, Academic -- UF
Genre: Veterinary Medical Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Laparoscopic surgery is a well established minimally invasive surgical modality in cats and dogs.  Currently, more emphasis is being placed on reducing the number of incisions required for laparoscopic procedures in order to reduce pain and morbidity associated with multiple incisions. To date, no evaluations of Single Incision Laparoscopic Surgery (SILS) ports have been reported in cats. The purpose of this study was to show that the use of these ports is both economically feasible and clinically applicable. Three SILS (TM) ports were utilized in the in vitro evaluation. The negative control port underwent decontamination and ethylene oxide sterilization without bacterial inoculation, the positive control port underwent bacterial inoculation without decontamination sterilization and the treatment port underwent bacterial inoculation followed by decontamination and ethylene oxide sterilization. Five testing cycles were conducted; during each time, a sample of the foam portion of each port was obtained and bacteriologic culture was performed. None of the treated port samples had positive culture results. All 5 positive control port samples had positive culture results. One negative control port sample grew a spore-forming Bacillus sp organism which was thought to be an environmental contaminant. In vivo evaluation of the port was performed by comparing three methods of laparoscopic sterilization in twenty-four healthy, female, domestic cats. Cats were randomly assigned to one of three groups: single incision laparoscopic ovariectomy-LigaSure (SILOVE-LS (n=8)), single incision laparoscopic ovariectomy-extracorporeal suture (SILOVE-ECS (n=8)) or open ovariectomy (open-OVE (n=8)). Single-incision laparoscopic ovariectomy was successful in (n=8) SILOVE-LS cats and (n=5) SILOVE-ECS cats. Surgical time was longer and more complications occurred in the SILOVE-ECS group. Post-operative pain was not different between groups. Our study demonstrates that decontamination and sterilization was effective for eliminating bacterial viability in a contaminated SILS (TM) port model. Also, ovariectomy performed with the SILS (TM) port is clinically applicable and safe in cats. Further in vitro and clinical testing is warranted to identify potential complications of reuse of this device, such as infection or port malfunction, before routine reuse of the port can be recommended.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by James G Coisman.
Thesis: Thesis (M.S.)--University of Florida, 2013.
Local: Adviser: Case, Joseph Bradly.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-05-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2013
System ID: UFE0045528:00001


This item has the following downloads:


Full Text

PAGE 1

1 EVALUATION OF A SINGLE INCISION LAPAROSCOPIC SURGERY PORT FOR FELINE LAPAROSCOPIC AND LAPAROSCOPIC ASSISTED SURGERY By JAMES G. COISMAN A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL F ULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2013

PAGE 2

2 2013 James G. Coisman

PAGE 3

3 To Natalie, Olivia, Kira, Adyson, and Sawyer

PAGE 4

4 ACKNOWLEDGMENTS I would like to tha nk my wife and girls for without your support and understanding this would not have come to fruition. I would also like to thank Brad Case and Gary Ellison for providing time, mentorship and advice over the course of these studies. Thank you to Andre Shih, Natalie Isaza, and Kelly Harrison for your advice and participation. Special thanks to Cat Monger for the coordination and scheduling of the lab, housing and technical assistance. We could not have done it without you. Additionally, many thanks are giv en to the cats and the rescue groups who provided them and then found them homes.

PAGE 5

5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ .. 4 LIST OF FIGURES ................................ ................................ ................................ .......... 7 LIST OF ABBREVIATIONS ................................ ................................ ............................. 9 ABSTRACT ................................ ................................ ................................ ................... 10 CHAPTER 1 AN INTRODUCTION TO LAPAROSCOPIC AND LAPAROSCOPIC ASSISTED SURGERY IN CATS ................................ ................................ ............................... 12 Background ................................ ................................ ................................ ............. 12 History ................................ ................................ ................................ ..................... 12 Laparoscopic Equipment ................................ ................................ ........................ 15 Telescopes ................................ ................................ ................................ ....... 16 Insufflators ................................ ................................ ................................ ........ 16 Cannulas and Ports ................................ ................................ .......................... 17 Basic Han d Instruments ................................ ................................ ................... 18 Hemostasis in Laparoscopic Surgery ................................ ................................ ..... 19 Bipolar Sealing Dev ices ................................ ................................ .................... 19 Extracorporeal Knots ................................ ................................ ........................ 20 Scientific Reports of Laparoscopy and Laparoscopic Assisted Surgery in Cats ..... 20 Summary ................................ ................................ ................................ ................ 21 2 EFFICACY OF DECONTAMINATION AND STERILIZATION OF SINGLE USE SINGLE INCISION LAPAROSCOPIC SURGERY PORTS ................................ ..... 30 Background ................................ ................................ ................................ ............. 30 Materials and M ethods ................................ ................................ ............................ 31 SILS Ports ................................ ................................ ................................ ........ 31 Sampling ................................ ................................ ................................ .......... 31 Microbial Contaminants ................................ ................................ .................... 32 Negative Control ................................ ................................ ............................... 32 Pos itive Control ................................ ................................ ................................ 32 Treatment Port ................................ ................................ ................................ 33 Decontamination and Sterilization ................................ ................................ .... 33 Culture Methodology ................................ ................................ ........................ 34 Data Analysis ................................ ................................ ................................ ... 34 Results ................................ ................................ ................................ .................... 35 Discussion ................................ ................................ ................................ .............. 35 Summary ................................ ................................ ................................ ................ 40

PAGE 6

6 3 COMPARISON OF SURGICAL VARIABLES IN CATS UNDE RGOING SINGLE INCISION LAPAROSCOPIC OVARIECTOMY USING A LIGASURE OR EXTRACORPOREAL SUTURE VERSUS OPEN OVARIECTOMY ....................... 43 Background ................................ ................................ ................................ ............. 43 Materials and Methods ................................ ................................ ............................ 44 Test Groups ................................ ................................ ................................ ...... 44 Inclusion Criteria and Group Assignment ................................ ......................... 45 Anesthesia ................................ ................................ ................................ ........ 45 Surgery ................................ ................................ ................................ ............. 45 SILOVE LS ................................ ................................ ................................ 46 SILOVE ECS ................................ ................................ ............................. 46 Open OVE ................................ ................................ ................................ 48 Closure ................................ ................................ ................................ ...... 48 Data Collection ................................ ................................ ................................ ....... 48 Surgical Time ................................ ................................ ................................ ... 48 Pain Scoring ................................ ................................ ................................ ..... 49 Data Analysis ................................ ................................ ................................ .......... 49 Results ................................ ................................ ................................ .................... 50 Signalment ................................ ................................ ................................ ....... 50 Surgical Time ................................ ................................ ................................ ... 50 Surgical Complications ................................ ................................ ..................... 50 Pain Evaluation ................................ ................................ ................................ 51 Visual analog score ................................ ................................ .................... 51 Simple descriptive scale ................................ ................................ ............ 52 Mechanical stimulation ................................ ................................ ............... 52 Discussion ................................ ................................ ................................ .............. 52 Signalment ................................ ................................ ................................ ....... 53 Surgery Time ................................ ................................ ................................ .... 53 Surgical Complications ................................ ................................ ..................... 55 Pain Evaluation ................................ ................................ ................................ 56 Limitations ................................ ................................ ................................ ........ 57 Summary ................................ ................................ ................................ ................ 58 4 CONCLUSION ................................ ................................ ................................ ........ 65 LIST OF REFERENCES ................................ ................................ ............................... 67 BIOGRAPHICAL SKETCH ................................ ................................ ............................ 75

PAGE 7

7 LIST OF FIGURES Figure page 1 1 Tele Pack; thi s system includes the monitor, light source and image capture device in one unit (photo courtesy of author). ................................ ..................... 22 1 2 High definition camera used for laparoscopy and other minimally inv asive surgery (photo courtesy of author). ................................ ................................ ..... 23 1 3 Fiberoptic light cable used for laparoscopy and other minimally invasive surgery (photo courtesy of author). ................................ ................................ ..... 24 1 4 Scopes used for laparoscopy and thoracoscopy. From top to bottom and left to right 11mm operating scope, 10 mm 0 degree scope, 10 mm 30 degree scope, 5 mm 0 degree scope, and 5 mm 0 degree scope (phot os courtesy of author). ................................ ................................ ................................ ............... 25 1 5 Insufflator used to control CO 2 for creation and maintenance of the pneumoperitoneum (photo courtesy of author). ................................ .................. 26 1 6 Variety of re usable and disposable cannulas available for laparoscopy. The SILS TM port with 5 mm cannula set is on the bottom right (photo courtesy of author). ................................ ................................ ................................ ............... 27 1 7 5 mm basic hand instruments for laparoscopy and thoracoscopy. From top to bottom 5 mm curved metzenbaum scissors, 5 mm Babcock grasping forceps, 5 mm curved Kelley grasping/ dissecting forceps (photos courtesy of author). ................................ ................................ ................................ ............... 28 1 8 LigaSure TM bipolar vessel sealing device with a 5 mm 37 mm handpiece (photo courtesy of author). ................................ ................................ ................. 29 2 1 A F oam portion of the SILS port. Note the concave central area. B The inset shows the porous nature of the foam. Not included in the image are the rigid cannulas that come with the port (photo courtesy of author). ............................. 41 2 2 SILS port with holes created by sampling with a 6 mm Baker punch (photo courtesy of author). ................................ ................................ ............................. 42 3 1 Intra operative image of the uterine horn and ovarian pedicle being elevated using the laparoscopic Babcock forceps. The inset shows the port and instruments (photo courtesy of author). ................................ .............................. 59 3 2 Illustration depicting the tying of a Meltzer knot through the SILS TM cannulas with instrumentation in place (Illustration courtesy of C. Moats). ........................ 60

PAGE 8

8 3 3 Box and Whisker plot illustrating surgery time by group: SILOVE L S, open OVE, and SILOVE ECS. The box represents the interquartile range, the center line the median, and the whiskers the minimum and maximum values. Different letters are present where significant differences exist ( P < 0.05). ........ 61 3 4 Visual analogue pain scores by group: open OVE, SILOVE LS, and SILOVE ECS. Different letters are present where significant differences exist ( P < 0.05). ................................ ................................ ................................ .................. 62 3 5 Simple descriptive pain scores by group: open OVE, SILOVE LS, and SILOVE ECS. Different letters are present where significant differences exist ( P < 0.05). ................................ ................................ ................................ ........... 63 3 6 Von Frey Filament palpation scores by group: open OVE, SILOVE LS, and SILOVE ECS. Different letters are present where significant differences exist ( P < 0.05). ................................ ................................ ................................ ........... 64

PAGE 9

9 LIST OF ABBREVIATIONS MIS minimally invasive surg ery SILS single incision laparoscopic surgery TSB trypson soy broth

PAGE 10

10 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science EVALUA TION OF A SINGLE INCISION LAPAROSCOPIC SURGERY PORT FOR FELINE LAPAROSCOPIC AND LAPAROSCOPIC ASSISTED SURGERY By James G. Coisman May 2013 Chair: J. Brad Case Major: Veterinary Medical Sciences Laparoscopic surgery is a well established minimally in vasive surgical modality in cats and dogs. Currently, more emphasis is being placed on reducing the number of incisions required for laparoscopic procedures in order to reduce pain and morbidity associated with multiple incisions. To date, no evaluations of Single Incision Laparoscopic Surgery (SILS) ports have been reported in cats. The purpose of this study was to show that the use of these ports is both economically feasible and clinically applicable. Three SILS TM ports were utilized in the in vitro evaluation. The negative control port underwent decontamination and ethylene oxide sterilization without bacterial inoculation, the positive control port underwent bacterial inoculation without decontamination sterilization and the treatment port underwent bacterial inoculation followed by decontamination and ethylene oxide sterilization. Five testing cycles were conducted; during each time, a sample of the foam portion of each port was obtained and bacteriologic culture was performed. None of the treated port samples had positive culture results. All 5 positive control port samples had positive culture results. One

PAGE 11

11 negative control port sample grew a spore forming Bacillus sp organism which was thought to be an environmental contaminant. In vivo evaluatio n of the port was performed by comparing three methods of laparoscopic sterilization in twenty four healthy, female, domestic cats. Cats were randomly assigned to one of three groups: single incision laparoscopic ovariectomy LigaSure (SILOVE LS (n=8)), si ngle incision laparoscopic ovariectomy extracorporeal suture (SILOVE ECS (n=8)) or open ovariectomy (open OVE (n=8)). Single incision laparoscopic ovariectomy was successful in (n=8) SILOVE LS cats and (n=5) SILOVE ECS cats. Surgical time was longer and m ore complications occurred in the SILOVE ECS group. Post operative pain was not different between groups. Our study demonstrates that decontamination and sterilization was effective for eliminating bacterial viability in a contaminated SILS TM port model. Also, ovariectomy performed with the SILS TM port is clinically applicable and safe in cats. Further in vitro and clinical testing is warranted to identify potential complications of reuse of this device, such as infection or port malfunction, before rout ine reuse of the port can be recommended.

PAGE 12

12 CHAPTER 1 AN INTRODUCTION TO LAPAROSCOPIC AND LAPAROSCOPIC ASSISTED SURGERY IN CATS Background Over the last three decades minimally invasive surgical techniques have found acceptance and in some cases have repla ced open surgical procedures in humans. 1 4 In the last decade, advances and availability of instrumentation, techniques, and client demand have been instrumental in the development of routine arthroscopic, flexible endoscopic, thoracoscopic, and laparoscopic evaluation and therapies in veterinary medicine. 5 11 Laparoscopy is now a well established modality for abdominal surgery in veterinary medicine. 12 17 Reported laparoscopic and laparoscopic assisted procedures in cats include o variectomy, ovariohysterectomy, liver biopsy, pancreatic biopsy, and recently enterotomy, as well as intestinal resection and anastomosis. 12 17 A main advantage of laparoscopic surgery is better visualization during the procedure, which may result in less risk of hemorrhage 18 19 and minimization of surgical inaccuracy, potentially reducing the chance of incomplete tissue excision and complications such as ovarian remnant syndrome. 20 Other benefits attributed to laparoscopy include reduction of pain in the postoperative period, 21 24 more expeditious recovery compared to laparotomy, 25 26 and less risk of infection. 27 History The history of endoscopy and therefore laparos copy in both human and orifices and internal cavities of their fellow man. In early civilization, Hippocrates (460 375 BC) is credited with the first use of a rectal spec ulum 28 29 A section in the Babylonian Talmud thought to be recorded around 65 BC describes t he use of a

PAGE 13

13 vaginal speculum to distinguish vaginal from uterine bleeding. 30 In the 9 th centu ry Abulkaism, an Arabian physician, is credited for using reflected light instead of direct light to visualize the inside of the vagina. 30 These precursors to current methods were all largely limited by the use of ambient light for illumination. In 1805, Phillipe Bozzini developed an instrument he named the Liechleiter or light conductor. This ma rked a transition to the use of an external light source. visualization and he published on its construction in 1806 31 and potential uses in 1807. 32 Unfortunately he succumbed to typhus in 1 8 1853 that Antonin Desormeaux, considered by many to be the father of modern endoscopy, was the first to use a n instrument similar to 33 doscope used an alcohol lamp for illumination. 33 The invention of a relatively durable incandescent lamp by Edison in 1879 34 and the incorporation of lenses into the scope to broaden the field of view, a long with moving the light source to the distal end of the device by Maximillian Nitze in 1887 35 greatly improved effective illumination. Up to the end of the 19 th century, endoscopy was con fined to procedures such as vaginoscopy, female cystoscopy, esophagoscopy, and gastroscopy. In 1901, the first reported endoscopic intra abdominal evaluation was attempted by Dimitri Ott. Dr. Ott, a Russian gynecologist, used a lamp, head mirror and spec ulum to peer into the abdominal cavity via a small incision through the posterior vaginal fornix. 36 Also in 1901, the first true laparoscopy in a live dog was performed by George Kelling a German surgeon. 37 Kel ling used a Nitze cystoscope and a self made insufflation device

PAGE 14

14 using sterile cotton filtered air to create a pneumoperitoneum. Kelling reported his findings in 1902 naming the procedure coelioscopy and the pneumoperitoneum Luft tamponade or air tamponad e. 37 38 In 1910 Hans Christian Jacobaeus published a number of clinical reports on laparoscopy, thoracoscopy, and pericardoscopy in humans ma king him one of the fathers of modern human endoscopy and he is credited with coining 37 39 While there are multiple reports of laparoscopic advances in humans during the first half of the 20 th century 37 only Anderson in 1937 reported using live dogs to investigate and improve laparoscopic skills and applications for use in human patients. 40 Anderson is also the first to report on laparoscopic steril ization in women using an electrode for endothermic coagulation. 40 growing interest in veterinary reproductive medicine lead to the use of laparoscopy to visualize the reproductive organs and more specifically the ovari es in several livestock, lab oratory animal and exotic species. 37 Laparoscopic approaches developed during this time of growth ranged from standing vaginal and paralumbar in mares 41 and cows 42 to ventral midline in sheep, 43 goats, 44 and pigs. 45 46 Along with the inves tigations in livestock in the 1970s, researchers started performing and reporting on laparoscopic techniques used in research dogs and cats. 37 In 1972, Lettow reported on the first laparoscopic assisted liver biopsy in the dog. 47 Wildt et al were the first to report on laparoscopic evaluation of the internal organs of cats and dogs in 1977. 48 That gro und breaking report demonstrated the potential for laparoscopy to be a safe and practical method of abdominal evaluation in cats and

PAGE 15

15 dogs. Since then there has been exponential growth in research and clinical reporting on the use of laparoscopy in the cat and dog. 12 15 17 18 21 23 26 27 49 54 Laparoscopic Equipment Laparoscopy in small animal practice requires a m onitor, camera, image capture device, light source, light transmitting cable, telescope, insufflator, telescope, cannulas or ports, hand instruments, and an ability to provide hemostasis when needed. 55 This instrumentation set can be tailored to the needs of a particular clinic setting or patient. The monitor can be as simple as a television set or computer screen, however, higher grade medical monitors may provide bette r imaging (Figure 1 1) 55 The camera and image capture device provides real time imag ing of the surgical site which is useful for recording images and video documentatio n of surgical findings and procedure s Digital three chip and high definition cameras provide the best color and image quality (Figure 1 2) The high definition camera produces the most color accurate, highest quality video and real time images with enha nced depth perception that may improve technical skills. 56 The image capture device is important for documentation and historical archiving of procedures and intraoperative findings. A light source provides the illumination to the surgical field via fiber optic light cable (Figure 1 3) Xenon and halogen light sources are the most commonly used with xenon producing a more white and consistent light. 55 Adequate wattage must be available to illuminate all intra abdominal areas. Additionally, the ability to control the intensity of the light is useful in areas where serosal or instrument reflection can be a problem. 57 This light control may be a function of the camera itself or in combination with the light source. 57

PAGE 16

16 Telescopes The most common rigid telescopes used in small animal laparoscopy are 2.7 mm and 5 mm diameter telescopes. 55 58 The 2.7 mm telescope is frequently used in smaller patients but is more fragile and typically requires the use of a 3.5 mm operating sleeve to protect the telescopes narrow s haft from bending during use. Additionally, there are larger 10 mm scopes that allow more light and a wider field of view, but this is at the expense of larger cannula and incision size. Alternatively, there is a 12 mm operating laparoscope that has an in corporated 5 mm telescope and 7 mm working channel; has been used in both cat s 14 and dog s 49 (Figure 1 4) The telescopes also come in a variety of viewing angles, the most common of which are the zero and thirty d egree variety. 55 58 techn ically easier to maneuver than an angled telescope; it is adequate for the majority of laparoscopic procedures performed in small animals. However, telescopes with a 58 This is especially advantageous for navigating around fixed anatomy like the liver or kidneys, visualizing deep or distant regions in the abdomen such as the lateral peritoneal gutters, and in triangulating instruments withi n the field of view when there is limited working space. Insufflators An insufflator is used to pump carbon dioxide into the abdomen to create a (Figure 1 5). 59 60 Landmark work done in the 1970s showed that cardiac output declines when intra abdominal pressure (IAP) exceed s 10 mm Hg and can be detrimentally effected if the pressure exceeds 15 mm Hg with up to 50% reduction in cardiac output at 20 mm Hg. 61 Quality insufflators

PAGE 17

17 possess both IAP and gas flow regulators to ma intain a safe working pressure within the peritoneal cavity. Most surgeons use 12 15 mm Hg IAP for initial trocar insertion This higher pressure provides greater distension creating more space between the body wall and viscera allowing safer entry of the initial trocar and cannula. T he IAP is then reduced to 6 8 mm Hg in order to maintain an adequate working space while limiting the potential deleterious effects on cardiac output and ventilation. 61 Although not commonly utilized, some insufflators are equipped with gas warmers and humidifiers to help mitigate potential adverse sequela e such as hypothermia and peritoneal desiccation, which can be seen with cold non humidified gas insufflation. 21 62 64 Cannulas and Ports Cannulas and ports come in a wide range of sizes, materials, and designs (Figure 1 6) A typical small animal laparoscopy set comes with three 5mm cannulas with two sharp and one blunt obturator for insertion, a 10 mm cannula with obturator and a cannula reducer from 11 mm to 5.5 mm. 55 In an effort to decrease the incidence of trocar induced injuries, screw in or threaded cannulas (Ternamian EndoTip TM Karl Storz, Veterinary Endoscopy, Goleta, CA ars for insertion were developed. Also available are several single use cannulas made from hard plastics that come in both threaded and smooth shaft styles. Some of these single use cannulas are available with self retracting trocars that immediately ret ract on penetration of the body wall and others that allow visualization at the tip of the trocar so that penetration into the abdominal or thoracic cavity can be visualized throughout placement. Recently, a movement towards fewer incisions in both human and veterinary minimally invasive surgery (MIS) has been recognized. To this end, several single incision multi cannulated surgical ports have been developed. The EndoCone TM is a

PAGE 18

18 resterilizable single incision multi instrument port developed by Karl Stor z. This port allows the passage of multiple instruments through a single 3 cm incision; h owever, its conical design and rigid walls necessitate using special sigmoid shafted or articulated instruments in order to overcome the difficulties of triangulation and instrument clashing inherent to single incision instrumentation. Several single use ports are also available including the Single Incision Laparoscopic Surgery (SILS) TM port from Covidien, the Uni x TM from Pnavel, as well as the Triport TM and Quad port TM series from Advanced Surgical Concepts. The material and design of these ports vary in stiffness and flexibility, which can necessitate using special sigmoid shafted or articulated instrumentation for many procedures. Basic Hand Instruments Laparo scopic hand instruments come in a vast array of types and configurations representing almost all of the instruments used in traditional surgery. Scissors, forceps, and retraction/ manipulation devices are the most commonly used in small animal laparoscopy (Figure 1 7) Instrumentation is available in both 5 mm and 10 mm diameters allowing use through most laparoscopic cannulas. The most basic 5 mm set of laparoscopic hand instruments should include a palpation probe, Babcock forceps, curved Kelley forcep s, biopsy forceps, and curved Metzenbaum scissors. 55 Many instruments are also available with curved or sigmoid shafts for improved triangulation when used in specialized single incision ports. However, most veterinary laparoscopic procedures can be performed utilizing straight shafted instruments. Additionally, many hand instruments can be attached to mono polar electrocautery for aid in hemostasis.

PAGE 19

19 Hemostasis in Laparosco pic Surgery th Tenet of Surgery, control of hemorrhage, applies to both open and laparoscopic surgery; however, extra diligence is essential for successful laparoscopic surgery as even small amounts of blood in the laparoscopic surgical field c an hinder visualization and result in conversion to an open celiotomy. 12 52 M ultiple modalities for controlling hemorrhage have been developed for use during laparoscopic surgery. Anderson is the first to report using endothermic coagulation to provide hemostasis during laparoscopic sterilization in women in 1 937. However, i that Semm reported on and championed thermocoagulation, extracorporeal knotting and Roeder Loop applicators for controlling bleeding during laparoscopic gynecological surgeries. 65 include the development of endoclips, endostaplers, laser, ultrasound sealing dev ices, bipolar tissue sealing devices, and advancements in intra and extracorporeal suturing. 16 18 19 24 53 55 66 68 In our study a bipolar device was chosen for its relative ease of use 18 50 55 and an extracorporeal suture knot for its technical difficulty. 18 55 68 Bipolar Sealing Devices Laparoscopic use of bipolar electrocoagulation was first reported in 1971 by Semm. 69 the first reported use of a feedback controlled bipolar vessel sealing emerged. 70 The principle behind this technology is t hat as the tissue is heated the impedance change is reported to a microprocessor in the generator. This feedback ensures the appropriate amount of heating and compression is provided to the tissue to melt collagen and elastin proteins into a sealing coagu lum. 70 Two of these sealers, the LigaSure TM (Figure 1 8) made by Covidien and the ENSEAL TM by Ethicon are reported to seal up to 7 mm vessels with similar amounts of thermal

PAGE 20

20 spread. 71 72 In addition, numerous veterinary studie s have demonstrated the efficacy and safety of these devices in sealing vessels and tissue. 14 15 18 21 22 26 49 51 53 67 71 72 Extracorporeal Knots S everal extracorporeal slip knots have been described for use in laparoscopic surgery. 66 68 73 These include, but are not limited to, the Roeder knot, modified Roeder knot (Meltzer knot), 4S modified Roeder (4SMR) knot, and Weston knot. The Weston knot r equires the addition of two or three intra corporeal throws for security thus greatly adding to its difficulty. 68 The Roeder knot, first widely used by Semm, has been shown to be significantly weaker than more recent modifications that include additional throws. 73 76 In addition to the number of throws, suture material and size also effect knot security. 74 76 In a recent study comparing the 4SMR and modified Weston knots the 4SMR had a higher slippage rate when tied with polyglactin 910 though all ligatures withstood testing with supraphysiologic pressures. 68 While the Meltzer knot was not friction created in the Metzler knot ma y provide additional resistance to slippage with braided suture such as the polyglactin 910. 68 76 Scientific Reports of Laparoscopy and Laparoscopic Assisted Surgery in Cats While reporting of laparoscopic advances has been prolific in human and canine literature in the last two decades little has been published i n cats. Ovariectomy 14 16 is the most commonly reported procedure with several studies evaluating either po rts or methods of hemostasis. Other reported procedures include ovariohysterectomy 6 cryptorchidectomy, 15 liver biopsy 6 pancreatic biopsy 6 77 enterotomy 78 intestinal resection and anastomosis 12 13 renal biopsy, 79 80 splenic biopsy 81 and splenectomy 82

PAGE 21

21 Summary The history of laparos copy stretches from the ancients, yet only in the last 30 years have significant breakthroughs and real development occurred. These recent advances in equipment and instrumentation have paved the way to wide acceptance of laparoscopic procedures in both h uman and veterinary patients. The benefits of laparoscopic surgery including better visualization 18 19 20 reduction of pain 21 24 faster recovery 25 26 and lower infection rate 27 personal experience and demand ha ve been instrumental in establish ing laparoscopy as an accepted modality for abdominal surgery in veterinary medicine. 12 17 Though still lagging in numbers in the literature when compared to human and canine studies, r eported laparoscopic and laparoscopic assisted procedures in cats include ovariectomy, ovariohysterectomy, liver biopsy, pancreatic biopsy, enterotomy and intestinal resection and anastomosis. 12 17

PAGE 22

22 Figure 1 1. Tele Pack; t his system includes the monitor, light source and image capture device in one unit (photo courtesy of author).

PAGE 23

23 Figure 1 2. High def inition camera used for laparoscopy and other minimally invasive surgery (photo courtesy of author).

PAGE 24

24 Figure 1 3. Fiberoptic light cable used for laparoscopy and other minimally invasive surgery (photo courtesy of author)

PAGE 25

25 Figure 1 4. Scopes used for laparoscopy and thoracoscopy. From top to bottom and left to right 11mm operating scope, 10 mm 0 degree scope, 10 mm 30 degree scope, 5 mm 0 degree scope, and 5 mm 0 degree scope (photos courtesy of author).

PAGE 26

26 Figure 1 5. Insufflator used to contr ol CO 2 for creation and maintenance of the pneumoperitoneum (photo courtesy of author).

PAGE 27

27 Figure 1 6. Variety of re usable and disposable cannulas available for laparoscopy. The SILS TM port with 5 mm cannula set is on the bottom right (photo courtesy o f author)

PAGE 28

28 Figure 1 7. 5 mm basic hand instruments for laparoscopy and thoracoscopy. From top to bottom 5 mm curved metzenbaum scissors, 5 mm Babcock grasping forceps, 5 mm curved Kelley grasping/ dissecting forceps (photos courtesy of author)

PAGE 29

29 Figure 1 8. L igaSure TM bipolar vessel sealing device with a 5 mm 37 mm handpiece (photo courtesy of author).

PAGE 30

30 CHAPTER 2 EFFICACY OF DECONTAMINATION AND STERILIZATION OF SINGLE USE SINGLE INCISION LAPAROSCOPIC SURGERY PORTS Background Decontamination a nd sterilization of laparoscopic SUDs for humans undergoing MIS is controversial. 83 86 Such devices are typically reused because of economic concerns, however reuse of disposable instruments may increase the risk infection for patients. 83 86 Single use surgical devices are typically made of less robust materials (plastics and rubber) than are non disposable surgical devices; therefore, decontamination and sterilization of SUDs can be difficult and such devices are prone to mechanical malfunction when reused. 83 86 Reuse of SUDs is common in the field of veterinary surgery. There are few reports of mechanical failure or adverse effects for animals when SUDs are reused for performance of sur of information is attributable to a lack of such effects or to underreporting of adverse events. Veterinarians typically reuse laparoscopic SUDs because of the high cost of such devices. Veterinary surgeons and surgeons performing procedures for humans in developing or poor countries 84 may have justification for reuse of SUDs during MIS because o f economic concerns. However, adverse effects of such reuse of devices may be different for humans and other animals. A disposable instrument port has been developed for use during single incision laparoscopic surgery of humans. Although the material compo sition of that port is proprietary information of the manufacturer, the device has a gross appearance similar to firm, malleable foam ( F igure 2 1). The advantage of this port for performance of

PAGE 31

31 laparoscopic surgery is that 3 to 4 instruments can simultaneo usly be used though a single short incision. Preliminary studies for dogs and cats indicate the device is useful for MIS in such animals 51 54 However, the cost of the device is approximately $400; therefore, use of the device by veterinarians for single incision laparoscopy of animals may be economically impractical. The purpose of the s tudy reported here was to determine the efficacy of decontamination and sterilization of a disposable port intended for use during single incision laparoscopy. We hypothesized that a commonly used method of surgical instrument decontamination and steriliza tion would be efficacious for elimination of bacteria on this laparoscopic instrument port Materials and Methods SILS Ports Three SILS TM ports were utilized for five test cycles in this study. Prior to the start of the study, the ports were randomly assig ned as a negative control, a positive control, and a treatment port by drawing a number from a bag. This port assignment remained the same for the duration of the study. Sampling All handling of the port and sampling was done using aseptic technique inc luding using single use sterile biopsy punches, blades and surgical latex gloves. Each port was sampled in the same manner, using a sterile 6 mm baker biopsy punch (Biopsy Punch; Integra Miltex, York, PA), following its respective treatment. The location o f sampling for all ports was in the central concave region of the port (Figure 2 2) The plastic inner cannulas and insufflation tubing were not included during testing.

PAGE 32

32 Microbial Contaminants The test microorganisms used in this study were Escherichia co li ATCC #25922, Staphylococcus aureus ATCC #29123, and Mycobacterium fortuitum (clinical isolate). Each isolate was grown separately in sterile tryptic soy broth (TSB) (TSB; Hardy Diagnostics, Santa Maria, CA) which was incubated at 95 +/ 2% humidity in 5% to 10% CO 2 at 35 to 37 0 C. The bacteria were combined and suspended in sterile deionized water with an approximate cell density of ca. 1.5 x 10 5 CFU/mL for each species. Negative Control For the negative control group, no treatment was performed. Inste ad, a SILS port was maintained in sterile wrap and resterilized in Ethylene Oxide (EtO) (EO Gas Series 3; Andersen Sterilizers, Inc. Haw River, NC) immediately following sampling. All handling of the port and sampling was done using aseptic technique inclu ding using single use sterile biopsy punches, blades and surgical latex gloves. The port was sampled in the same m anner from the central concave region using a sterile 6 mm baker biopsy punch (Biopsy Punch; Integra Miltex, York, PA) at each test cycle and placed in a 5ml aliquot of sterile TSB which was incubated in 95 +/ 2% humidity and 5% to 10% CO 2 at 35 to 37 0 C. Samples were examined at 18 to 24 h ours and again after a minimum of 48 hours for growth. Positive Control The positive control port was expo sed to E coli American Type Culture Collection No. 25922, S aureus American Type Culture Collection No. 29123, and M fortuitum (isolated from a clinical patient and identified via DNA sequence analysis). Each bacterial isolate was incubated separately in T SB at 95 +/ 2% humidity in 5% to 10% CO 2 at 35 to 37C. The bacteria were combined and suspended in sterile deionized

PAGE 33

33 water with a cell density of approximately 1.5 X 10 5 CFUs/mL of each species. The positive control port was submerged in the bacterial s uspension for 30 minutes at approximately 21C Then, port material samples were collected with a sterile biopsy punch. Port material samples obtained at each of the 5 testing times were placed in 5 mL of sterile TSB d and incubated at 95 +/ 2% humidity in 5% to 10% CO 2 at 35 to 37C. Bacteriologic cultures of positive control port material were examined at 18 to 24 hours after the start of incubation to detect E coli and S aureus growth and from 48 hours to 1 week after that time to detect M fortuitum gro wth. Treatment Port The treatment port was exposed to the same mixture as the positive control port of the following bacteria: Escherichia coli ATCC #25922, Staphylococcus aureus ATCC #29123, and Mycobacterium fortuitum (clinical isolate). Each isolate wa s grown separately in TSB and incubated as described for the negative controls. The bacteria were combined and suspended in sterile deionized water with an approximate cell density of ca. 1.5 x 10 5 CFU/mL for each species. The port was submerged in the bac terial composite solution for 30 minutes. Decontamination and Sterilization Instead of immediate sampling, the treatment port was decontaminated via rinsing with tap water for 1 minute and soaked in a enzymatic cleaner (dilution, 3:100) (Bio zyme; Osceola Supply, Tallahassee, FL) and brushed with a sponge scrub brush and pipe cleaner brush for 5 minutes. The port was then rinsed with tap water, dried with compressed air, and packaged and heat sealed in plastic wrap. The wrapped port was then exposed to ethy lene oxide for 16 hours by use of a standard protocol 87 at 50C and > 30% humidity, as determined by use of a humidity chip (Humidichip;

PAGE 34

34 Andersen Products, Haw River, NC). Sterilization indicators (EtO Gas dosimeter; Andersen Products, Haw River, NC) were use d to ensure sterile conditions were attained during the ethylene oxide sterilization cycle. After sterilization, a port material sample was collected and aerobic bacteriologic culture was performed via the same method used for negative and positive control ports. Culture Methodology Each TSB tube was visually inspected for growth (turbidity) and sub cultured onto Columbia Base with 5% sheep blood (CBA; Hardy Diagnostics, Santa Maria, CA), Columbia base with 5% sheep blood and colistin and nalidixic acid (CN A; Hardy Diagnostics, Santa Maria, CA), and MacConkey (MAC; Hardy Diagnostics, Santa Maria, CA) agar to confirm the presence or absence of each species of bacteria. Plates were incubated at 95 +/ 2% humidity in 5% to 10% CO 2 at 35 to 37 0 C for 18 to 24 hou rs for detection of E coli and S aureus M fortuitum Data Analysis For each species of bacteria detected for each port material sample, an ordinal score was assigned. Scores assigned for each port material sample included 0 (no bacteria detected), 1 (1 speci es of bacteria detected), 2 (2 species of bacteria detected), or 3 (3 species of bacteria detected). Data were expressed as median and range values. A Wilcoxon signed rank test and a Kruskal Wallis rank sum test with 2 approximation were used to determine statistical differences in bacterial culture scores among ports. Values of P < 0.05 were considered significant. Statistical analysis was performed by use of software (JMP 9.0; SAS, Cary, NC).

PAGE 35

35 Results Significant ( P = 0.003) differences in bacterial cul ture scores were detected among groups of port material samples. Bacteriologic culture scores for the 5 positive control port material samples (median score, 3 [range, 1 to 3]) were significantly ( P = 0.010) higher than those for the 5 negative control por t material samples (median score, 0 [range, 0 to 1]). For the negative control port sample obtained during the first test, bacteriologic culture results were positive for a spore forming Bacillus sp. The positive control port material sample obtained durin g that time had positive bacteriologic culture results for all 3 species of inoculated bacteria and the treated port material sample obtained during that time had negative bacteriologic culture results. None of the treated port material samples had positiv e bacteriologic culture results. A significant difference in the bacterial growth score was detected between the treated port material samples (median, 0 [range, 0 to 0]) and positive control port material samples ( P = 0.006) but not between the treated po rt material samples and negative control port material samples ( P = 0.42). Discussion Results of the present study indicated decontamination and sterilization of the multichannel laparoscopy port was effective. These findings suggest that this port may be reused for performance of MIS in animals However, further studies are indicated t o determine whether reuse of the device would cause complications such as infection in animals or equipment mal function. The multichannel single use laparoscopy port is a uni que peritoneal access device because it permits simultaneous passage of 3 to 4 cannulas through a single 20 to 30 mm incision. 51 54 This method may have advantages over traditional laparoscopic

PAGE 36

36 techniques, which require creation of an incision for each instrument. A m ain benefit of a single incision laparoscopic technique are creation of a small incision and minimization of the number of incisions created and instrument cannula s used during a procedure 51 54 Use of techniques in which the number and size of incisions are reduced is becoming common in MIS for human s 88 89 and other animals 21 49 51 54 In the used in the present study has been useful for performance of laparoscopic assisted gastrointestinal tract exploratory surgery. Further, for small pa tients, the port allows exteriorization of organs ( such as portions of the intestinal tract ) for performance of extracorporeal procedures without increasing the size of the original incision. This technique may decrease morbidity of animals undergoing MIS compared with that for animals undergoing traditional open surgical techniques. 6 21 27 49 88 89 Therefore use of this port by veterinarians may become more comm on for performance of MIS in animals However, the port has a high cost ( $400 ) Because this port is labeled as an SUD, decontamination and sterilization of the device are not advised by the manufacturer However, results of the present study suggest ed tha t decontamination and sterilization of the device may be effective for reduction of the number of bacteria which may allow safe reuse of the port for laparoscopic procedures in animals Reuse of SUDs for laparoscopy of human s is controversial. Because few complications of reuse of such devices have been detected and the devices are expensive, reuse of SUDs may be justifiable. 84 90 Results of other studies 84 90 indicate adverse clinical sequela of reuse of SUDs have not been detected and the cost of surgical materials for open and laparoscopic surgical procedures for humans may be

PAGE 37

37 substantially ( > $3,000) different However, total costs of open and laparoscopic surgical procedures (including hospitalization costs) ma y be similar or such costs for laparoscopic procedures may be less than those for open surgical procedures for some human patients 90 Findings for veterinary pa tients may be similar. Reuse of SUDs has potential disadvantages P atients undergoing surgical procedures in which SUDs are reused may have higher risk of infectio n versus patients undergoing surgical procedures in which such devices are not reused, becaus e of incomplete decontamination of SUDs or injury attributable to mechanical failure of such device s 83 86 Incomplete r emoval of organic material (determined via s canning electron microscopy and radionuclide labeling techniques) may occur in up to 100% of contaminated SUDs that have been cleaned 85 86 Although low amounts of residual organic material w ere found on SUDs in th o se studies, appropriate disinfection of microb ial organisms was achieved via the methods that were used in the studies 85 86 Determin ation of the clinical relevance of the results of those studies may be difficult, because multiple factors may affect such findings inc luding type of device used amount of prior use of a device species of animal undergoing surgical procedures and procedures used for decontamination and sterilization of a device Little information is available regarding clinical complications associate d with reuse of SUDs in animals undergoing surgery Other authors 91 estimated that infection is caused by contaminated endoscopic instruments in only 1 of 1.8 million procedures for humans Fu rther studies may be indicated to determine the risks and complications a ssociated with reuse of SUDs for animals undergoing surgical procedures

PAGE 38

38 In the present study w e attempted to determine the possibility of transmission of infectio us bacteria to ani mals by a reused multichannel laparoscopy port via assess ment of the efficacy of decontaminat ion and steriliz ation techniques that are typically used for surgical instruments This was thought to b e important information because of the malleable and porous properties of the port s The species of bacteria used for inoculation of ports in the present study were selected because they were thought to be representative of various bacteria that typically cause c ontamination of instruments and infection of animals after surgery 92 The concentration of each species of bacteria used in the present study ( 1.5 X 10 5 CFUs/mL ) was intended to simulate instrument contamination severe enough to cause infection in animals A Mycob acterium sp was included because th e response of organisms of this genus to disinfectants is different from that of Staphylococcus spp and organisms of the family Enterobacteriaceae, and this organism is a reported cause of infection in humans that undergo laparoscopy in countries in which sterilization and reuse of SUDs is commonly performed 93 The technique used to decontaminate and sterilize laparoscopi c ports in the present study was the same technique used in our hospital for cleaning and sterilization of similar surgical materials. Results of this study indicated bacteria were not detected in treated port material samples after decontamination and ste rilization. Thus, the decontamination and sterilization protocol used in the present study may be appropriate for preparation of SUDs for reuse in a clinical setting Further studies of this decontamination and sterilization technique for SUDs used during clinical procedures of animals are warranted

PAGE 39

39 Several limitations of the present study were identified. The ports were not tested to detect vi r uses fung i or protozoa. Although transmission of vir uses among human patients is a n important concern, it may n ot be as important for dogs undergoing surgery because viral diseases of dogs may have lower prevalence and virulence than those of humans However, transmission of some viral pathogens of dogs undergoing surgery, such as hepatitis C virus may be an impor tant concern 94 In addition, FIV and FeLV may be transmitted on instrument between cats undergoing surgery. Postoperative fungal infections in humans ( especially infections caused by Candida spp organisms) are increasing in prevalence, and further studies of d isinfection techniques for fungi are warranted 95 Another limi tation of the present study was that laparoscopic ports were not exposed to blood or other biological fluid s of animals; exposure of ports to such fluids might alter the efficacy of the cleaning and sterilization technique used for devices in th e study. Ad ditionally, no ne of the ports were subjected to mechani cal trauma in this study and each port was tested only 5 times T he structural integrity of such ports, and therefore the ability to effectively decontaminate and sterilize them may be altered with re pe ated use ; however, t his was not evaluated in the present study and conclusions regarding that possibility could not be determined. Finally, only the foam portion s of laparoscopic port s w ere tested via bacteriologic culture P lastic cannulas and insufflat ion tubing of ports were not test ed We did not test those portions of the ports because we thought that th e se rigid structures would be less likely to harbor bacteria after decontamination and sterilization versus the foam portions of the ports

PAGE 40

40 Summary R esults of this study suggested that decontamination and sterilization was effective for reducing the number of bacteria on laparoscopic port s intended for single use. The se results may support reuse of this SUD for MIS of animals Reuse of the laparoscopic port may be safe for animals and economically beneficial for veterinarians. However, further in vitro and clinical testing is warranted to identify potential complications of reuse of this device, such as infection in animals or port malfunction before r outine reuse of the port can be recommended

PAGE 41

41 Figure 2 1 A Foam portion of the SILS port. No te the concave central area. B The inset shows the porous nature of the foam. Not included in the image are the rigid cannulas that come with the port (photo courtesy of author)

PAGE 42

42 Figure 2 2. SILS port with holes created by sampling with a 6 mm Baker punch (photo courtesy of author)

PAGE 43

43 CHAPTER 3 COMPARISON OF SURGICAL VARIABLES IN CATS UNDERGOING SINGLE INCISION LAPAROSCOPIC OVARIECTOMY USING A LIGASURE OR E XTRACORPOREAL SUTURE VERSUS OPEN OVARIECTOMY Background Ovariohysterectomy (OHE) and ovariectomy (OVE) are common surgical procedures performed in small animal practice. Laparoscopy is an established surgical modality in veterinary surgery. 12 17 Currently reported laparoscopic and laparoscopic assisted procedures in cats include ovariectomy, ovariohysterectomy, liver biopsy, pancreatic biopsy, and recently, enteroto my, as well as intestinal resection and anastomosis. 12 17 A reported advantage of laparoscopic surgery in dogs is better visualization during the procedure, which may result in less risk of hemorrhage 18 19 potentially reducing the chance of incomplete tissue excision resulting in ovarian remnant syndrome. 20 Other benefits include reduction of pain in the postoperative period, 21 24 more expeditious reco very compared to laparotomy, 25 26 and less risk of infection. 27 The severity of postoperative pain is likely related to the degree of soft tissue trauma, 21 24 96 pH of the peritoneal fluid, 63 and duration of the surgical procedure. 21 62 Because of the known advantages of MIS in other species, there is increased interest in performing new MIS techniques in cats. 13 16 53 Ligation of ovarian blood vessels during open ovariectomy involves direct vessel ligation whereas vessel attenuation during laparoscopic ovari ectomy can be done using extracorporeal placed sutures or by using electronic sealing devices. Additionally, specially designed single incision devices, such as the SILS port ( SILS TM port, Covidien, Mansfield, MA ) have allowed the use of multiple instrumen ts through a single port and have helped to facilitate such advances. However, use of new devices, especially those designed for

PAGE 44

44 different species, requires cautious preliminary evaluation prior to advocating use. Ovariectomy should be an appropriate model to evaluate the feasibility and versatility of the SILS port for laparoscopic abdominal surgical procedures in cats. Thus, the aims of this study were to 1) evaluate the feasibility and versatility of the SILS port for laparoscopic ovariectomy (SILOVE), and 2) to compare operative time, complications and postoperative pain in cats undergoing SILOVE using either a bipolar sealing device (5mm Blunt Tip LigaSure TM Covidien, Mansfield, MA) or extracorporeal modified Roeder knot of 3 0 polyglactin 910 (Vicryl Ethicon Inc., Somerville, NJ), versus traditional open ovariectomy. Our hypotheses were that laparoscopic SILOVE in cats using a SILS port was feasible, safe, and associated with a longer operative time, but no more postoperative discomfort compared to open OVE via a 20 mm incision. To evaluate these hypotheses, we performed SILOVE in cats using a LigaSure (SILOVE LS; n=8) and extracorporeal suture (SILOVE ECS; n=8). Open OVE was also performed in (n=8) cats for comparison. Surgery time, operative compli cations, and postoperative pain scores were recorded and compared between groups. Materials and Methods Test Groups This study was approved by the University of Florida, Institutional Animal Care and Use Committee. Twenty four, intact, not pregnant female cats were recruited over a three week period from local animal rescue groups. All cats were admitted and examined at least one day prior to surgery.

PAGE 45

45 Inclusion Criteria and Group Assignment Signalment, estimated age, and body weight were recorded for all cats. All cats were assessed as normal based on physical examination, Packed Cell Volume (30 45%), Total Protein (6.3 8.6) and Blood Urea Nitrogen (5 15) analysis (Azostix, Siemens Healthcare Diagnostics Inc., Tarrytown, NY) prior to anesthesia and surger y. Cats were randomly assigned to one of three treatment groups, single incision laparoscopic ovariectomy LigaSure ( SILOVE LS ( n=8) ) single incision laparoscopic ovariectomy extracorporeal suture ( SILOVE ECS (n=8) ) or open ovariectomy ( OVE (n=8) ) by dr awing numbers from an opaque bag. Anesthesia Cats were premedicated with 0.02 mg/kg buprenorphine (Buprenex, Reckitt Benckiser Pharmaceuticals Inc, Richmond, VA) given intramuscularly (IM). After five minutes, an intravenous (IV) catheter was placed in a cephalic vein. Anesthesia was induced with 4 10 mg/kg propofol (Propoflo, Abbott Laboratories, North Chicago, IL) IV to effect, and maintained with isofluorane in 100% oxygen using mechanical ventilation (Hallowell Model 2000, Hallowell EMC, Pittsfield, MA), Electrocardiography (ECG), pulse oximetry, indirect blood pressure, capnography, venous blood gas analysis, and trans esophageal echocardiography were used for anesthesia monitoring. Surgery All cats were positioned in dorsal recumbency and aseptica lly prepared for surgery. A standardized 20mm ventral midline celiotomy was created directly over the umbilicus in all cats.

PAGE 46

46 SILOVE LS Stay sutures using 3 0 Glycomer 631 (Biosyn, Covidien, Mansfield, MA) were placed through the rectus sheath on each side of the celiotomy and lifted to aid in port insertion. Two curved carmalt forcep s were used to compress the bottom lip of the SIL S port and a small amount of sterile lubrication (Surgilube, Savage Labs, Melville, NY) was applied to the port. The port was advanced into the celiotomy u p to the box lock of the first Carmalt which was then released and removed. The remainder of the port was then advanced and the second carmalt released and removed. Once the SILS port was inserted into the celiotomy, three 5 mm inner cannulas were inserted into the port and the abdomen insufflated to 6 mmH g with CO 2 (20L High Flow Insufflator, Stryker Endoscopy, Santa Clara, CA). A 5 mm, 0 o rigid telescope ( Hopkins II telescope, Karl Storz, Veterinary Endoscopy, Goleta, CA) w as inserted through the SILS and a limited abdominal explore was performed. The cat was tilted into left dorsal oblique recumbency and the right ovary was located, grasped at the proper ligament and elevated ventrally with 5 mm laparoscopic Babcock Forceps [( Clickline, Babcock Forceps, Karl Storz, Veterinary Endoscopy, Goleta, CA) Figure 3 1 ]. A 5 mm LigaSure was used to ligate and divide the ovarian pedicle, suspensory ligament, and proper ligament. The abdomen was then desufflated to facilitate removal o f the SILS and ovary. The cat was returned to dorsal recumbency and the SILS placed back into the celiotomy. The cat was then tilted into right dorsal oblique recumbency and the left ovary was removed in the same manner. SILOVE ECS The SILS was inserted peritoneal insufflation accomplished and initial exploration performed in the same manner as for the SILOVE LS group. The cats were

PAGE 47

47 initially tilted into left dorsal oblique recumbency and the right ovary was located, grasped by the proper ligament and e levated ventrally with 5 mm Babcock Forceps. A 5 mm laparoscopic scissor ( Clickline, Scissors, Karl Storz, Veterinary Endoscopy, Goleta, CA) was used to fenestrate the mesovarium between the ovarian artery and proper ovarian ligament. 3 0 polyglactin 910 was passed through an inner cannula and through the fenestration with 5mm laparoscopic Kelly forceps ( Clickline, Kelly Forceps, Karl Storz, Veterinary Endoscopy, Goleta, CA) and released. The tissue was then relaxed dorsally and the free end of the suture recovered from the other side of the tissue with the Kelly forceps and brought back out the inner cannula. An extracorporeal modified Roeder knot 66 ( Figure 3 2 ) was tied and then tightened using a laparoscopic knot pusher (Knot Pusher 66173K, Karl Storz, Veterinary Endoscopy, Goleta, CA). This was repeated for each ovarian pedicle and uterine horn (adjacent to the proper ovarian ligament). The ovarian pedicle an d uterine horn (adjacent to the proper ovarian ligament) were each ligated with 3 0 polyglactin 910 using extracorporeal modified Roeder knots 66 tightened using a laparoscopic knot pusher (Knot Pusher 66173K, Karl Storz, Veterinary Endoscopy, Goleta, CA). The ovarian pedicles and uterine horns were then transected approximately 5mm distal to the ligatures using the 5mm laparoscopic scissors. The abdomen was then desufflated to facilitate removal of the SILS and ovary. The SILS and ovary were then removed from the abdominal cavity. The cat was returned to dorsal recumbency and the SILS placed back into the celiotomy. The cat was then tilted into right dorsal obl ique recumbency and the left ovary was removed in the same manner.

PAGE 48

48 Open OVE The right ovary was located with a spay hook and then exteriorized by strumming the suspensory ligament. A mosquito forceps was used to grasp the proper ovarian ligament. A fene stration was made in the mesovarium. The ovarian pedicle was ligated with 3 0 Glycomer 631 using a single encircling ligature and transected. The uterine horn was ligated, adjacent to the proper ovarian ligament, using 3 0 Glycomer 631 and transected. T he left ovary was removed in the same manner. Closure Closure was standardized for all three treatment groups. The linea was closed using 3 0 Glycomer 631 in a simple continuous pattern. The subcutis was closed using 3 0 Glycomer 631 in a simple continuo us subcuticular pattern. Tissue glue (GLUture, Abbott Laboratories, North Chicago, IL) was used to seal the skin. All cats were administered 0.1 mg/ kg meloxicam (Metacam, Boehringer Ingelheim Vetmedica, St. Joseph, MO) subcutaneously (SC) at extubation. Data Collection Surgical Time Surgical time was defined as time of skin incision to time of skin closure for all groups. Surgical complications were recorded and coded based on whether or not further surgical intervention was required. Scores were 0 non e, 1 minor, requiring no intervention, 2 minor, requiring surgical intervention but no alteration of the incision, 3 major, requiring enlargement of the incision and conversion to exploratory laparotomy.

PAGE 49

49 Pain Scoring Pain scores were assigned by one of two observers (Isaza and Harrison) who were blinded to the surgical treatment. Pain scores were determined prior to anesthesia, and at 1, 2, 3, and 4 hours after extubation using, in the following order, a Visual Analogue Scale (VAS) 97 99 a Simple Descriptive Scale (SDS) 99 101 (table 1), and via mechanical stimulation of the incision site with an automated von Frey meter (VFF [The ProD, Top Cat Metrology LTD, CAMBS]) 97 102 103 The VFF was set to a ramp rate of 0.5N/sec and a 4mm tip was used for all evaluations. At each time point, VFF stimulation was performed and recorded three times at a negative control site (righ t lateral abdomen) and three times in the center of the incision. The average of the 3 results was used for comparison between groups. Data Analysis Continuous data was summarized as median and range or as mean SD if normally distributed. One way ANOV variance was used to test for differences in age, body weight, and surgical time. A Tukey Kramer test was used for post hoc analysis. Complications were compared squared contingency analysi s. Repeated measures ANOVA was used to test for differences in VAS, SDS, and VFF pain scoring. The Wilcoxon Method was used to make nonparametric comparisons between pairs. All analyses were performed with standard commercial software (JMP 8; SAS Institu te INC, Cary, NC). Values of P <0.05 were considered significant.

PAGE 50

50 Results Signalment Twenty Four healthy, intact, female cats (n=8/ group) were included in this study. The mean SD age of the cats was 16.5 6.8 months and did not differ significantly b etween groups ( P =0.73). The mean body weight of the cats was 3.02 0.35 kg and also did not differ significantly between groups ( P =0.16). Surgical Time Median surgical time was 25.5 minutes (range, 16 30 minutes) for the SILOVE LS group, 71 minutes (ra nge, 50 128 minutes) for the SILOVE ECS group, and 17.5 minutes (range, 13 23 minutes) for the open OVE group (Figure 3 3). Surgical time was significantly different between groups ( P <0.001). Extracorporeal suture SILOVE took significantly longer than S ILOVE LS (P<0.001) as well as open OVE (P<0.001). There was no significant difference in surgery time between the SILOVE LS and open OVE groups (P = 0.55). Surgical Complications Surgical complications were more frequent in the SILOVE ECS group than the SILOVE LS ( P =0.049) and the open OVE ( P =0.008) groups. The frequency of complications was not significantly different between the SILOVE LS and open OVE groups ( P =0.13). Surgical complications included hemorrhage from the right uterine horn distal to the ligature (n=1) and from the left uterine horn distal to the ligature (n=2) in the SILOVE ECS group. In each case, hemorrhage was considered mild and was controlled by exteriorizing the horn through the original celiotomy and tying a second ligature. In t his same group, one of the modified Roeder knots either failed to slide (n=2) or broke (n=1) during tightening. No hemorrhage was seen and each suture was

PAGE 51

51 replaced with a new extracorporeal modified uterine horn (n =1), a dropped ovary (n=1) and a small peritoneal thermal injury (n=1) occurred in the SILOVE LS group. The hemorrhage was controlled easily with a second application of the LigaSure; the dropped ovary was easily retrieved through the existing incision aft er removal of the port and the thermal injury required no treatment. There was no mortality associated with this study. Follow up was conducted by phone interview with or in the case of adoptions through the rescue groups at ten days and six months post o peratively. No complications were reported by the rescue groups or new owners. Moderate (5 8mm, measured intra operatively with a graduated scalpel handle) stretching of the original 20 mm incision was observed immediately following removal of the SIL S po rt in both the SILOVE LS (n=8) and SILOVE ECS (n=8) groups. Pain Evaluation Visual analog score No significant differences in preoperative pain scores were present between groups ( P =0.99) according to the VAS. Cats in each group had significantly higher VAS pain scores at 1 hour postoperative when compared to preoperative VAS scores (P=0.0025), but VAS scores were not different across groups (P=0.76) (Figure 3 3). However, at the four hour time point alone, the SILOVE ECS group pain score was significantl y higher compared to SILOVE LS ( P = 0.011) but not significantly higher than the open OVE cats ( P =0.18). No significant difference was seen between SILOVE LS and open OVE cats ( P =0.31)

PAGE 52

52 Simple descriptive scale No significant differences in SDS preoperativ e pain scores existed between groups ( P = 0.99). Cats in each group had significantly higher SDS pain scores at 1 hour postoperative when compared to preoperative SDS scores (P=0.0001), but SDS scores were not different across groups (Figure 3 4) at any po stoperative time point (1 hr, P =0.42; 2 hr, P =0.76; 3 hr, P =0.99; 4 hr, P =0.49). Mechanical stimulation No significant differences in preoperative response to Von Frey Filament palpation existed between groups ( P =0.12). Cats in each group had significantl y higher percent change in VFF pain scores at 1 hour postoperative when compared to preoperative VFF scores (P<0.0001), but percent change in VFF score was not different across groups (Figure 3 5) at any postoperative time point (1 hr, P =0.27; 2 hr, P =0.40 ; 3 hr, P =0.20; 4 hr, P =0.13). Discussion We have demonstrated that use of a SILS for SILOVE is feasible and versatile in cats. Although extracorporeal suturing via the SILS was effective the use of a modified Roeder knot failed in 3 cats, increased the risk of hemorrhage and took significantly longer than the LigaSure technique. Further, SILOVE using the SILS (regardless of technique) resulted in similar post operative pain as an open OVE of equal incision length. Laparoscopic ovariectomy using a SI LS appears to offer few advantages over traditional open ovariectomy in cats, but may be beneficial in maintaining a minimally invasive environment for other advanced laparoscopic and laparoscopic assisted procedures when compared to traditional celiotomy approaches.

PAGE 53

53 Signalment Young, healthy, intact, female cats were included to eliminate variability in patient characteristics and to model patients seen in a typical clinical practice. No significant differences in age and body weight were seen between gr oups, which further limited the opportunity for bias between groups. Laparoscopic procedures were jointly performed by the same two surgeons (Case and Coisman), to maintain clinical consistency. This was particularly important in the modified Roeder knot group, which would have been difficult to perform safely without the second surgeon. Conversely, all open OVE procedures were performed by a single surgeon (Case or Coisman), which supports open OVE as a better option for routine sterilization in cats. All cats were anesthetized using the same protocol and no anesthetic complications occurred. The protocol used was consistent with what might be performed in clinical practice. Insufflation pressure was also standardized between SILOVE groups and was limi ted to 6 mmHg. This low insufflation pressure provided adequate working space within the peritoneal cavity as reported in a previous study. 16 Surgery Time Average surgical time was 2 5 minutes for the SILOVE LS group and 17 minutes for the open OVE group, which is consistent with the previous studies reported in dogs and cats. 16 18 19 21 23 49 51 63 96 Although operative times did not differ significantly between these groups, it is possible that type 2 statistical error may have precluded such a finding. However, only in the laparoscopy cats was a limited exploration of the peritoneal cavity performed. The ability to evaluate the peritoneal cavity is one of the advantages of the SILS techniques over an open OVE. Because initial e xploration of the peritoneum is recommended after port insertion during laparoscopic procedures, we

PAGE 54

54 did not consider the limited exploratory as a separate procedure; it was included in the surgery time. Subjectively, the additional time required to explore the abdominal cavity was less than 1 minute, but argues against the chance of statistical type 2 statistical error affecting surgical time comparison. Not surprisingly, these operative times were both significantly shorter than the SILOVE ECS group, which averaged about 70 minutes. The much longer operating time in the SILOVE ECS group was due to inherent technical difficulties associated with the procedure. First, each suture had to be passed via an inner cannula through the mesovarium, then grasped and passed back around the mesovarium before exteriorizing through the same inner cannula. Careful coordination between the surgeon and assistant was required to perform this safely. It was also important that half the length of the suture, be placed intraco rporeally; the pedicle be brought to the inner cannula as the suture was passed and exteriorized to avoid sawing of the tissue during suture passage. Once the suture was passed, the extracorporeal modified Roeder knot was formed while the assistant maintai ned intracorporeal visualization of the ovarian pedicle and suture. The knot pusher was then used to slide and tighten the knot for ligation of the ovarian and uterine tissues. This procedure was completed 4 times in each cat in the SILOVE ECS group; it is the major reason as to why operating time was significantly longer in this group. This is in contrast to the SILOVE LS group in which ligation and division of the ovarian tissues is accomplished efficiently without the use of suture. 18 The reason we included the SILOVE ECS group in our study was to better evaluate the versatility of the SILS. The success with the modified Roeder procedure offers support for use of the

PAGE 55

55 SILS in this application and may also be helpful with other extracorporeal suture procedures, such as pancreatic or lymph node biopsy. Of course, careful attention to technique and the risk of bleeding should be considered prior to this application. Surgical Complications Although complications were more frequent in the SILOVE ECS group compared to both SILOVE LS and open OVE groups, the procedure was considered to be safe, as alteration of the incision was not necessary to correct the observed complications. However, removal of the SILS port was required to complete the procedure in 3 cats. The ability to remove the port and to exteriorize the ovarian pedicle via the 20 mm celiotomy is interesting in that it demonstrates the ports versatility an d potential for laparoscopic assisted applications, such as laparoscopic assis ted gastrointestinal procedures. 6 Surgical complications were typical of those previously reported for laparoscopic ovariectomy. 1,3,5,7,8,10 12 Mild hemorrhage was the most c ommon complication and was easily controlled in the SILOVE ECS group by exteriorizing the uterine horn through the celiotomy and by tying a second ligature. The one cat in the SILOVE LS group that had mild bleeding was controlled with a second application of the LigaSure. An unanticipated, but interesting observation was moderate (5 8mm) stretching of the original incision, which was seen in the SILOVE cats. This observation is not reported with SILS port use in other veterinary species. The tissue stretc hing did not alter the seal formed around the port and no CO2 leakage was appreciated. Additionally, after tissue recoil and closure there was no appreciable difference in the lengths of the closed incisions in either SILP or open groups. It is unknown if or how incisional stretching may have affected surgery time and or postoperative pain, but it

PAGE 56

56 may be another potential benefit in laparoscopic assisted procedures where exteriorization of bowel and other organs is indicated. 6 Pain E valuation Significa nt differences in preoperative and postoperative pain using the VAS, SDS and incisional palpation with VFF for up to 4 hours following surgery were not seen between groups, with a single exception at the 4 hour postoperative time point in which cats in the SILOVE ECS group were more painful than cats in the SILOVE LS group. The overall similarity in postoperative pain scores between groups was not unexpected given that incision length and the amount of soft tissue resection was kept consistent between group s. However, there were distinct differences between the three procedures, which may have impacted the level of postoperative discomfort. First, there is speculation that insufflation of the abdomen with CO 2 gas may play a role in discomfort for a number of possible reasons including elevated intra abdominal pressure, which may stretch the phrenic nerves, peritoneal acidosis, and desiccation of the peritoneal surface due to the lack of humidification of the insufflated peritoneal CO 2 gas. 21 62 64 Further, stretching of the incision, which was seen in the SILOVE cats, may have caused increased discomfort compared to t he open OVE cats which did not experience incisional stretching. In human patients, single incision techniques tend to be associated with similar postoperative discomfort compared to traditional multiport procedures. Thus, incisional stretching noted here may not have a significant effect on postoperative pain, but this is not known. Another consideration is the method of ligation of the ovarian pedicle, which was different between groups. It is possible that strumming or tearing of the suspensory ligam ent from the peritoneum as was performed in our open OVE cats, may lead to

PAGE 57

57 more postoperative pain versus ligation via bipolar cautery or scissors. Again, no significant differences were seen between groups and other differences also existed, which makes a nswering this question outside the scope of the study. Finally, at the 4 hour postoperative time point, cats in the SILOVE LS group were found to have lower pain scores via the VAS than were cats in the SILOVE ECS group. Whether or not this was an isolat ed finding or the beginning of a trend is unknown. It is possible that the longer operative time in the SILOVE ECS group played a role; conversely, statistical error may be to blame. Limitations A number of limitations must be acknowledged when interpretin g results of the present study. First, sample size was relatively small, which may have precluded detection of significant differences between groups. For example, cats undergoing open OVE had an average surgery time of 17 minutes while cats in the SILOVE LS group had an average surgery time of 25 minutes. While this difference was not statistically important, it is possible that with the addition of more cases, statistical significance may have been reached. Second, the research setting is a more controlle d environment and may not reflect the conditions of the clinical setting, making extrapolation of some results difficult. While all pain scales used in the current study have been validated in small animals, there are inherent limitations with interpreting animal behaviors as painful and this is always done with caution. Thirdly, two pain scorers were used. While no statistically significant differences were seen between the two scorers this may inherently add variability to the data. Additionally, while we did not include traditional two port laparoscopic ovariectomy in our study, this could be considered as an area for future investigation.

PAGE 58

58 Summary In conclusion, SILOVE using a SILS is feasible, versatile, and safe in cats. Use of a LigaSure for ovarian pedicle ligation was faster and associated with fewer complications than the extracorporeal suture method, but not different that open OVE. Single incision laparoscopic ovariectomy using a SILS alone appears to offer few advantages over traditional open ov ariectomy, but may be beneficial in minimizing tissue trauma in more advanced laparoscopic and laparoscopic assisted procedures such as laparoscopic assisted gastrointestinal surgery when compared to traditional celiotomy approaches.

PAGE 59

59 Figure 3 1. Int ra operative image of the uterine horn and ovarian pedicle being elevated using the laparoscopic Babcock forceps. The inset shows the port and instruments (photo courtesy of author)

PAGE 60

60 Figure 3 2. Illustration depicting the tying of a Meltzer knot throu gh the SILS TM cannulas with instrumentation in place (Illustration courtesy of C. Moats)

PAGE 61

61 Figure 3 3 Box and Whisker plot illustrating surgery time by group: SILOVE LS, open OVE, and SILOVE ECS. The box represents the interquartile range, the center line the median, and the whiskers the minimum and maximum values. Different letters are present where significant differences exist ( P < 0.05).

PAGE 62

62 Figure 3 4 Visual analogue pain scores by group: open OVE, SILOVE LS, and SILOVE ECS. Different letters are present where significant differences exist ( P < 0.05).

PAGE 63

63 Figure 3 5 Simple descriptive pain scores by group: open OVE, SILOVE LS, and SILOVE ECS. Different letters are present where significant differences exist ( P < 0.05).

PAGE 64

64 Figure 3 6 Von Frey Filament palpation scores by group: open OVE, SILOVE LS, and SILOVE ECS. Different letters are present where significant differences exist ( P < 0.05).

PAGE 65

65 CHAPTER 4 CONCLUSION Chapter 1 provided a n historical overview of the history of laparoscopy in hu mans and veterinary medicine including the development of instrumentation and equipment essential to performing these techniques. Recent advances in minimally invasive surgical equipment and instrumentation have paved the way for wide acceptance of laparo scopic procedures in both human and veterinary patients. The benefits of laparoscopic surgery including better visualization, 18 19 20 reduction of pain, 21 24 faster recovery, 25 26 and lower infection rate 27 are well documented. Client demand has been instru mental in establishing laparoscopy as an accepted modality for performing abdominal surg ical procedures in veterinary practice 12 17 Literature fully supporting t he justification and establishing the efficacy of laparoscopic procedures in cats is still lacking, however, reported laparoscopic and laparoscopic assisted procedures in cats include ovariectomy, ovariohysterectomy, liver biopsy, pancreatic biopsy, entero tomy and intestinal resection and anastomosis. 12 17 No ne of these studies report using the SILS port for laparoscopic or laparoscopic assisted surgeries in cats. W hile the re in veterinary practice the ability to effectively decontaminate the SILS TM port was unknown. Unlike many of the re use able SUDS that are composed of hard plastics and metals, the body of the SILS TM port is proprietary, semi porous porous foam. In C hapter 2 we evaluated the SILS TM port s soil ed with bacterial species representative of those commonly encountered during abdominal surgery and also been previously implicated in post operativ e infection s Our culture results suggest that decontamination and sterilization

PAGE 66

66 was effective in reducing the number of bacteria on this SUD and may support reuse of the port in animals. In vivo evaluation of the port was performed in C hapter 3 We recr uited twenty four healthy, intact female cats for the study. Cats were randomly divided into one of three surgical groups: SILOVE LS (n=8), SILOVE ECS (n=8), and open OVE (n=8). Surgery time, intra and post operative complications, and post operative pai n were compared between groups. Surgery time was significantly longer and complications were more frequent in the SILOVE ECS when compared to the SILOVE LS and open OVE groups. Post operative pain was not different between the three groups. Incidentally incisions in the two SILS port groups revealed stretching immediately after port removal. This stretching of the incision did not affect any of the outcome paramenters measured in these cats. Surgery was safely performed in all cats without any major c omplications or mortality. Cats were returned to rescue groups and adopted at the completion of the evaluation. Based on the results of this study we conclude that the SILS TM port can be safely used for laparoscopic ovariectomy and is clinically applicabl e for other laparoscopic and laparoscopic assisted surgery in cats. Additional in vitro and clinical testing is warranted to identify potential complications such as infection in animals or port malfunction associated with reuse of this device before ro utine reuse of the port can be recommended

PAGE 67

67 LIST OF REFERENCES 1 Jatzko GR, Lisborg PH, Pertl AM, et al : Multivariate comparison of complications after laparoscopic cholecystectomy and open cholecystectomy. Ann S urg 221:381 386, 1995. 2 Koffron A, Geller D, Gamblin TC, et al : Laparoscopic liver surgery: Shifting the management of liver tumors. Hepatology 44:1694 1700, 2006. 3 Liu Z, Zhang P, Ma Y, et al : Laparoscopy or not: a meta analysis of the surgical effect s of laparoscopic versus open appendicectomy. Surg Laparosc Endosc Percutan Tech 20:362 370, 2010. 4 Aziz O, Athanasiou T, Tekkis PP, et al : Laparoscopic versus open appendectomy in children: a meta analysis. Ann Surg 243:17 27, 2006. 5 Monnet E: Interven tional thoracoscopy in small animals. Vet Clin North Am Small Anim Pract 39:965 975, 2009. 6 Monnet E, Twedt DC: Laparoscopy. Vet Clin North Am Small Anim Pract 33:1147 1163, 2003. 7 Lansdowne JL, Mehler SJ, Boure LP: Minimally invasive abdominal and thora cic surgery: techniques. Compend Contin Educ Vet 34:E1 E11, 2012. 8 Lansdowne JL, Mehler SJ, Boure LP: Minimally invasive abdominal and thoracic surgery: principles and instrumentation. Compend Contin Educ Vet 34:E1 9, 2012. 9 Sum S, Ward CR: Flexible endo scopy in small animals. Vet Clin North Am Small Anim Pract 39:881 902, 2009. 10 Harasen G: What's new in orthopedics in 2005 -part I. Can Vet J 46:1136 1137, 2005. 11 Harasen G: What's new in orthopedics? Part 2. Can Vet J 48:1081 1082, 2007. 12 Buote NJ, Kovak McClaran JR, Schold JD: Conversion from diagnostic laparoscopy to laparotomy: risk factors and occurrence. Vet Surg 40:106 114, 2011. 13 Gower SB, Mayhew PD: A wound retraction device for laparoscopic assisted intestinal surgery in dogs and cats. Vet Surg 40:485 488, 2011. 14 Kim YK, Lee SY, Park SJ, et al : Feasibility of single portal access laparoscopic ovariectomy in 17 cats. Vet Rec 169:179, 2011.

PAGE 68

68 15 Miller NA, Van Lue SJ, Rawlings CA: Use of laparoscopic assisted cryptorchidectomy in dogs and ca ts. J Am Vet Med Assoc 224:875 878, 865, 2004. 16 van Nimwegen SA, Kirpensteijn J: Laparoscopic ovariectomy in cats: comparison of laser and bipolar electrocoagulation. J Feline Med Surg 9:397 403, 2007. 17 Webb CB, Trott C: Laparoscopic diagnosis of pancr eatic disease in dogs and cats. J Vet Intern Med 22:1263 1266, 2008. 18 Mayhew PD, Brown DC: Comparison of three techniques for ovarian pedicle hemostasis during laparoscopic assisted ovariohysterectomy. Vet Surg 36:541 547, 2007. 19 Van Goethem BE, Rosenv eldt KW, Kirpensteijn J: Monopolar versus bipolar electrocoagulation in canine laparoscopic ovariectomy: a nonrandomized, prospective, clinical trial. Vet Surg 32:464 470, 2003. 20 Ball RL, Birchard SJ, May LR, et al : Ovarian remnant syndrome in dogs and cats: 21 cases (2000 2007). J Am Vet Med Assoc 236:548 553, 2010. 21 Case JB, Marvel SJ, Boscan P, et al : Surgical time and severity of postoperative pain in dogs undergoing laparoscopic ovariectomy with one, two, or three instrument cannulas. J Am Vet Me d Assoc 239:203 208, 2011. 22 Culp WT, Mayhew PD, Brown DC: The effect of laparoscopic versus open ovariectomy on postsurgical activity in small dogs. Vet Surg 38:811 817, 2009. 23 Devitt CM, Cox RE, Hailey JJ: Duration, complications, stress, and pain of open ovariohysterectomy versus a simple method of laparoscopic assisted ovariohysterectomy in dogs. J Am Vet Med Assoc 227:921 927, 2005. 24 Hancock RB, Lanz OI, Waldron DR, et al : Comparison of postoperative pain after ovariohysterectomy by harmonic scal pel assisted laparoscopy compared with median celiotomy and ligation in dogs. Vet Surg 34:273 282, 2005. 25 Bohm B, Milsom JW, Fazio VW: Postoperative intestinal motility following conventional and laparoscopic intestinal surgery. Arch Surg 130:415 419, 19 95. 26 Davidson EB, Moll HD, Payton ME: Comparison of laparoscopic ovariohysterectomy and ovariohysterectomy in dogs. Vet Surg 33:62 69, 2004. 27 Mayhew PD, Freeman L, Kwan T, et al : Comparison of surgical site infection rates in clean and clean contamina ted wounds in dogs and cats after minimally invasive versus open surgery: 179 cases (2007 2008). J Am Vet Med Assoc 240:193 198, 2012.

PAGE 69

6 9 28 Sutton CJG, Diamond MP: Endoscopic surgery for gynaecologists, W.B. Saunders, 1993. 29 Rosin RD: Minimal access medici ne and surgery: principles and techniques, Radcliffe Medical Press, 1993. 30 Semm K: Atlas of gynecologic laparoscopy and hysteroscopy. Philadelphia, Saunders, 1977. 31 Bush RB, Leonhardt H, Bush IV, et al : Dr. Bozzini's Lichtleiter. A translation of his original article (1806). Urology 3:119 123, 1974. 32 Bozzini P: Der Lichtleiter oder die Beschreibung einer einfachen Vorrichtung innerer Hhlen und Zwischenrume des lebenden animalischen Krpers. Verlag des landes Industrie Comptoir, Weimar, 1807. 33 D esormeaux AJ: The Endoscope, and Its Application to the Diagnosis and Treatment of Affections of the Genito urinary Passages: Lessons Given at Necker Hospital, R. Fergus' sons, printers, 1867. 34 Israel P: Edison: A Life of Invention, Wiley, 1998. 35 Cabot H: Modern urology : in original contributions by American authors. London, H. Kimpton, 1936. 36 von Ott D: Die unmittelbare beleuchtung der bauchhohle, der harnblase, des dickdarms nd der gebarmutter zu diagnostischen und operativen zwecken. Mschr Geb Gyn akol 18:645 673, 1903. 37 Harrison RMe, Wildt DE : Animal laparoscopy. Baltimore, Williams & Wilkins, 1980. 38 Kelling G: Ueber Oesophagoskopie, Gastroskopie und Kolioskopie. Munch Med Wochenschr 49:21 24, 1902. 39 Jacobaeus HC: Ueber die mglichkeit die zy stoskopie bei untersuchung serser hhlungen anzuwenden. Munch Med Wochenschr 57 2090 2092, 1910. 40 Anderson ET: Peritoneoscopy. The American Journal of Surgery 35:136 139, 1937. 41 Witherspoon DM, Talbot RB: Ovulation site in the mare. J Am Vet Med Assoc 157:1452 1459, 1970. 42 Megale F, Fincher MC, McEntee K: Peritoneoscopy in the cow: visualization of the ovaries, oviducts, and uterine horns. Cornell Vet 46:109 112, 1956.

PAGE 70

70 43 Roberts EM: Endoscopy of the reproductive tract of the ewe Proc Aust Soc Anim P rod 1:192 194, 1968. 44 Dukelow WR, Jarosz SJ, Jewett DA, et al : Laparoscopic examination of the ovaries in goats and primates. Lab Anim Sci 21:594 597, 1971. 45 Wildt DE, Fujimoto S, Spencer JL, et al : Direct ovarian observation in the pig by means of l aparoscopy. J Reprod Fertil 35:541 543, 1973. 46 Wildt DE, Morcom CB, Dukelow WR: Laparoscopic pregnancy diagnosis and uterine fluid recovery in swine. J Reprod Fertil 44:301 304, 1975. 47 Lettow E: Laparoscopic examinations in liver diseases in dogs. Vete rinary Medicine Review 2:159 167, 1972. 48 Wildt DE, Kinney GM, Seager SW: Laparoscopy for direct observation of internal organs of the domestic cat and dog. Am J Vet Res 38:1429 1432, 1977. 49 Dupre G, Fiorbianco V, Skalicky M, et al : Laparoscopic ovarie ctomy in dogs: comparison between single portal and two portal access. Vet Surg 38:818 824, 2009. 50 Gower S, Mayhew P: Canine laparoscopic and laparoscopic assisted ovariohysterectomy and ovariectomy. Compend Contin Educ Vet 30:430 432, 2008. 51 Manassero M, Leperlier D, Vallefuoco R, et al : Laparoscopic ovariectomy in dogs using a single port multiple access device. Veterinary Record 171:69, 2012. 52 McClaran JK, Buote NJ: Complications and need for conversion to laparotomy in small animals. Vet Clin Nor th Am Small Anim Pract 39:941 951, 2009. 53 Sakals S, Rawlings CA: Laparoscopic Assisted Ovariectomy Using a Bipolar Vessel Sealing Device, Proceedings, 2011 American College of Veterinary Surgeons Veterinary Symposium November 3 5 Chicago, Illinois 54 Wi lson DM M onnet E: The use of single incision laparoscopic surgery (SILS Port) in dogs: Description of the technique and initial impressions after 22 consecutive cases Proc 9th Annual Scientific Meeting of the Veterinary Endoscopy Society, Park City, Utah p 22, 2012 55 Rawlings CA, Tams TR: Small animal endoscopy (ed 3rd ed.). St. Louis, Mo, Elsevier Mosby, 2011. 56 Hagiike M, Phillips EH, Berci G: Performance differences in laparoscopic surgical skills between true high definition and three chip CCD vide o systems. Surg Endosc 21:1849 1854, 2007.

PAGE 71

71 57 Bax K MA, Georgeson KE, Rothenburg SS : Endoscopic surgery in infants and children. Berlin ; New York, Springer, 2008. 58 Lhermette P, Sobel D, Sobel DS: BSAVA manual of canine and feline endoscopy and endosurger y. Gloucester, British Small Animal Veterinary Association, 2008. 59 Ott DE: Correction of laparoscopic insufflation hypothermia. Journal of laparoendoscopic surgery 1:183 186, 1991. 60 Sajid MS, Mallick AS, Rimpel J, et al : Effect of heated and humidifie d carbon dioxide on patients after laparoscopic procedures: a meta analysis. Surg Laparosc Endosc Percutan Tech 18:539 546, 2008. 61 Richardson JD, Trinkle JK: Hemodynamic and respiratory alterations with increased intra abdominal pressure. Journal of Surg ical Research 20:401 404, 1976. 62 Fredman B, Jedeikin R, Olsfanger D, et al : Residual pneumoperitoneum: a cause of postoperative pain after laparoscopic cholecystectomy. Anesth Analg 79:152 154, 1994. 63 Duerr FM, Twedt DC, Monnet E: Changes in pH of per itoneal fluid associated with carbon dioxide insufflation during laparoscopic surgery in dogs. Am J Vet Res 69:298 301, 2008. 64 Alexander JI, Hull MG: Abdominal pain after laparoscopy: the value of a gas drain. Br J Obstet Gynaecol 94:267 269, 1987. 65 Se mm K: Tissue puncher and loop ligation -new aids for surgical therapeutic pelviscopy (laparoscopy) = endoscopic intraabdominal surgery. Endoscopy 10:119 124, 1978. 66 Freeman LJ: Veterinary endosurgery, Mosby, 1999. 67 Risselada M, Ellison GW, Bacon NJ, et al : Comparison of 5 surgical techniques for partial liver lobectomy in the dog for intraoperative blood loss and surgical time. Veterinary Surgery 39:856 862, 2010. 68 Fugazzi RW, Fransson BA, Curran KM, et al : A Biomechanical Study of Laparoscopic 4S M odified Roeder and Weston Knot Strength in 3 0 Polyglactin 910 and 3 0 Polydioxanone. Veterinary Surgery 42:198 204, 2013. 69 Lau WY, Leow CK, Li AKC: History of Endoscopic and Laparoscopic Surgery. World Journal of Surgery 21:444 453, 1997. 70 Kennedy JS, Stranahan PL, Taylor KD, et al : High burst strength, feedback controlled bipolar vessel sealing. Surgical Endoscopy 12:876 878, 1998.

PAGE 72

72 71 Diamantis T, Kontos M, Arvelakis A, et al : Comparison of Monopolar Electrocoagulation, Bipolar Electrocoagulation, U ltracision, and Ligasure. Surgery Today 36:908 913, 2006. 72 Person B, Vivas DA, Ruiz D, et al : Comparison of four energy based vascular sealing and cutting instruments: a porcine model. Surgical Endoscopy 22:534 538, 2008. 73 Shettko DL, Frisbie DD, Hend rickson DA: A Comparison of Knot Security of Commonly Used Hand Tied Laparoscopic Slipknots. Veterinary Surgery 33:521 524, 2004. 74 Sharp HT, Dorsey JH, Chovan JD, et al : A simple modification to add strength to the Roeder knot. J Am Assoc Gynecol Laparo sc 3:305 307, 1996. 75 Sharp HT, Dorsey JH, Chovan JD, et al : The effect of knot geometry on the strength of laparoscopic slip knots. Obstet Gynecol 88:408 411, 1996. 76 Shimi SM, Lirici M, Vander Velpen G, et al : Comparative study of the holding strengt h of slipknots using absorbable and nonabsorbable ligature materials. Surg Endosc 8:1285 1291, 1994. 77 Webb C, Trott C: Laparoscopic diagnosis of pancreatic disease in dogs and cats. Journal of Veterinary Internal Medicine 22:1263 1266, 2008. 78 Evans SE, Bonczynski JJ, Broussard JD, et al : Comparison of endoscopic and full thickness biopsy specimens for diagnosis of inflammatory bowel disease and alimentary tract lymphoma in cats. J Am Vet Med Assoc 229:1447 1450, 2006. 79 Grauer G, Twedt D, Mero K: Eval uation of laparoscopy for obtaining renal biopsy specimens from dogs and cats. J Am Vet Med Assoc 183:677, 1983. 80 Vaden SL, Levine JF, Lees GE, et al : Renal Biopsy: A Retrospective Study of Methods and Complications in 283 Dogs and 65 Cats. Journal of V eterinary Internal Medicine 19:794 801, 2005. 81 Radhakrishnan A, Mayhew PD: Laparoscopic splenic biopsy in dogs and cats: 15 cases (2006 2008). J Am Anim Hosp Assoc 49:41 45, 2013. 82 : Laparoscopic splenectomy: operat ive technique and outcome in three cats. J Feline Med Surg 15:48 52, 2013. 83 Chan ACW, Ip M, Koehler A, et al : Is it safe to reuse dispos able laparoscopic trocars? Surgical Endoscopy 14:1042 1044, 2000. 84 Hamamci EO, Besim H, Bostanoglu S, et al : Use o f laparoscopic splenectomy in developing countries: analysis of cost and strategies for reducing cost. J Laparoendosc Adv Surg Tech A 12:253 258, 2002.

PAGE 73

73 85 Yoon JH, Yoon BC, Lee HL, et al.: Comparison of sterilization of reusable endoscopic biopsy forceps b y autoclaving and ethylene oxide gas. Dig Dis Sci 57:405 412, 2012. 86 Roth K, Heeg P, Reichl R: Specific hygiene issues relating to reprocessing and reuse of single use devices for laparoscopic surgery. Surg Endosc 16:1091 1097, 2002. 87 Slatter D: Textbo ok of Small Animal Surgery (ed 3). Philadelphia, PA, Saunders, 2003. 88 Kaouk JH, Goel RK, Haber GP, et al.: Robotic single port transumbilical surgery in humans: initial report. BJU Int 103:366 369, 2009. 89 Prasad A, Mukherjee KA, Kaul S, et al.: Postope rative pain after cholecystectomy: Conventional laparoscopy versus single incision laparoscopic surgery. J Minim Access Surg 7:24 27, 2011. 90 Rescorla FJ, Breitfeld PP, West KW, et al.: A case controlled comparison of open and laparoscopic splenectomy in children. Surgery 124:670 675; discussion 675 676, 1998. 91 Kimmery MB, Burnett DA, Carr Locke DL, et al.: Transmission Of Infection By Gastrointestinal Endoscopy. Gastrointestinal Endoscopy 39:885 888, 1993. 92 Kirby JP, Mazuski JE: Prevention of surgical site infection. Surg Clin North Am 89:365 389, viii, 2009. 93 Vijayaraghavan R, Chandrashekhar R, Sujatha Y, et al.: Hospital outbreak of atypical mycobacterial infection of port sites after laparoscopic surgery. J Hosp Infect 64:344 347, 2006. 94 Kapoor A, Simmonds P, Gerold G, et al.: Characterization of a canine homolog of hepatitis C virus. Proc Natl Acad Sci U S A 108:11608 11613, 2011. 95 Wallace WC, Cinat ME, Nastanski F, et al.: New epidemiology for postoperative nosocomial infections. Am Surg 66:8 74 878, 2000. 96 Alves AE, Ribeiro AP, Filippo PA, et al.: Evaluation of creatine kinase (CK) and aspartate aminotransferase (AST) activities after laparoscopic or conventional ovariectomy in queens. Schweiz Arch Tierheilkd 151:223 227, 2009. 97 Lascelles BDX, Cripps PJ, Jones A, et al.: Efficacy and Kinetics of Carprofen, Administered Preoperatively or Postoperatively, for the Prevention of Pain in Dogs Undergoing Ovariohysterectomy. Veterinary Surgery 27:568 582, 1998.

PAGE 74

74 98 Slingsby LS, Waterman Pearson AE: Comparison of pethidine, buprenorphine and ketoprofen for postoperative analgesia after ovariohysterectomy in the cat. Veterinary Record 143:185 189, 1998. 99 Cambridge AJ, Tobias KM, Newberry RC, et al.: Subjective and objective measurements of postopera tive pain in cats. J Am Vet Med Assoc 217:685 690, 2000. 100 Firth AM, Haldane SL: Development of a scale to evaluate postoperative pain in dogs. J Am Vet Med Assoc 214:651 659, 1999. 101 Holton L, Pawson P, Nolan A, et al.: Development of a behaviour base d scale to measure acute pain in dogs. Veterinary Record 148:525 531, 2001. 102 Dixon MJ, Taylor PM, Steagall PVM, et al.: Development of a pressure nociceptive threshold testing device for evaluation of analgesics in cats. Research in Veterinary Science 8 2:85 92, 2007. 103 Grint NJ, Murison PJ, Coe RJ, et al.: Assessment of the influence of surgical technique on postoperative pain and wound tenderness in cats following ovariohysterectomy. J Feline Med Surg 8:15 21, 2006.

PAGE 75

75 BIOGRAPHICAL SKETCH Coisman grew up on a small farm in upstate New York. He graduated from the University of Central Florida in 1999 with a b achelor s degree in b iology and a minor in m icrobiology and m olecular b iology. In 2004, he earned a Doctorate of Veterinary Medicine from the University of Florida. MAJ Coisman first joined the military in 1989 when he went through Marine Corps boot camp at Parris Island, SC. As a marine, he was stationed in Twenty Nine Palms, CA; Fort Gordon, GA; Camp Lejeune, NC; and Okinawa Japan. In November 1993 MAJ Coisman left active duty and entered the Marine Corps Reserve. While most of his reserve duties revolved around Special Operations Command, McDill AFB, Tampa, FL, he performed several periods of active duty in support of various other commands. From 2001 2004 MAJ Coisman was on a Health Professions Scholarship while attending the University of Florida, College of Veterinary Medicine. He th en returned to active Duty in June of 2004 as a clinical intern at the Military Working Dog Center at Lackland AFB in San Antonio, Texas. He has since served as Officer in Charge of the Moody Air Force Base Veterinary Treatment Facility in Valdosta, Georg ia and as Chief, Fort Shafter Branch Veterinary Services, Fort Shafter Hawaii. In July 2010 the Army selected MAJ Coisman to return to the University of Florida, College of Veterinary Medicine to complete a residency in small animal surgery. He is curren tly finishing his last year of the residency. MAJ Coisman is married to the former Ms. Natalie Carse of Chagrin Falls, Ohio. They have three daughters, Olivia, Kira, Adyson and a son, Sawyer.