Robotically assisted laparoscopic microsurgical uterine horn anastomosis

Transcription

1 FERTILITY AND STERILITY VOL. 70, NO. 3, SEPTEMBER 1998 Copyright 1998 American Society for Reproductive Medicine Published by Elsevier Science Inc. Printed on acid-free paper in U.S.A. Robotically assisted laparoscopic microsurgical uterine horn anastomosis Harout Margossian, M.D.,* Antonio Garcia-Ruiz, M.D., Tommaso Falcone, M.D.,* Jeffrey M. Goldberg, M.D.,* Marjan Attaran, M.D.,* and Michel Gagner, M.D. Cleveland Clinic Foundation, Cleveland, Ohio Objective: To evaluate the feasibility, safety, and sterility issues with regard to the use of a robotic device to perform uterine horn anastomosis in a live porcine model. Design: Prospective animal study. Setting: Landrace-Yorkshire pigs in a conventional laboratory setting. Intervention(s): Six female pigs underwent laparoscopic bipolar electrocoagulation of the distal uterine horns. Two weeks later, the uterine horns were reanastomosed laparoscopically with use of a robotic system for microsuturing. Necropsy was performed 4 weeks later to assess postoperative adhesions and anastomosis patency. Main Outcome Measure(s): Tubal patency; secondary measures were operative time, complications, and surgeon fatigue. Result(s): The mean ( SD) total operative time per animal was minutes including setting up and dismantling the robotic arms. The robot functioned well with only minor technical problems. All pigs survived both surgeries with no perioperative complications related to the use of the robot. Patency was confirmed after completing each anastomosis (12 anastomoses; 100% patency). Four weeks later, necropsy showed that eight anastomoses were still patent (67%). Only one pig had bilateral occlusion. Surgeon s fatigue was mild for each animal study. Conclusion(s): Robotic technology can be used safely in creating laparoscopic microsurgical anastomoses. The robot functioned properly in a sterile operating room environment. Adequate patency rates were achieved during the acute phase and at 4-week follow-up. Robotic technology has the potential to make laparoscopic microsuturing easier. (Fertil Steril 1998;70: by American Society for Reproductive Medicine.) Key Words: Animal, uterine horns, microsurgery, sterilization reversal, surgery, laparoscopic, robotics Received February 2, 1998; revised and accepted April 9, Supported by Computer Motion Inc., Goleta, California. Reprint requests: Tommaso Falcone, M.D., Department of Gynecology and Obstetrics/A81, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio (FAX: ). * Department of Gynecology and Obstetrics. Minimally Invasive Surgery Center /98/$19.00 PII S (98) It has been estimated that approximately 10% of the 6 million American women who undergo tubal sterilization surgery regret their decision and that 1% request tubal reanastomosis to restore fertility (1). Microsurgical tubal anastomosis can be performed successfully under an operating microscope via a laparotomy incision (2). Although most gynecologic operative procedures for benign conditions now are performed routinely with use of a laparoscopic approach, laparoscopic microsurgical anastomosis is still not practical. This long procedure requires extensive intracorporeal suturing and an extremely fine, precise microsurgical suturing technique, which is difficult to achieve with the operator s hands positioned so far from the operative field. Surgeon fatigue and discomfort further compromise fine motor control. Initial attempts to perform this procedure met with limited success (3 5). A recent nonrandomized study found pregnancy rates comparable with those achieved with open microsurgery (6). The possible advantages of the laparoscopic approach are greater cosmesis, reduced postoperative discomfort with more rapid return to activity, reduced cost, and fewer postoperative complications including adhesion formation. The recent development and expansion of robotic technology in the manufacturing industry has demonstrated that robots can outperform humans in several tasks that require a precise repetitive motion. This improvement is especially true if the position required to perform the task is uncomfortable or awkward. Robots are used in industry to perform mundane but exacting tasks, such as motor vehicle assembly, welding, painting, and more exotic tasks, such as removing fleece from sheep. The robot (i.e., robotic arm) first used in laparoscopic surgery was the Automated Endo- 530

2 scopic System for Optimal Positioning (Aesop, Computer Motion, Inc., Goleta, CA) (7). Recently, Zeus (Computer Motion, Inc.), a new robotic enhancement technology was developed specifically to facilitate laparoscopic microsuturing. Experimental studies evaluating robotic assistance in laparoscopic microsuturing and anastomosis in other procedures, such as coronary bypass surgery, have been encouraging (7, 8). The primary objective of this study was to evaluate the Zeus robotic system in performing laparoscopic microsurgical anastomosis in a live porcine uterine horn model. This is the first animal survival study assessing the feasibility of using a robotic system to perform laparoscopic microsurgery. FIGURE 1 Robotic arms and laparoscopic instruments positioned for laparoscopic microsurgical anastomosis in the live porcine model. MATERIALS AND METHODS The study was approved by the Animal Research Committee of the Cleveland Clinic Foundation. Six female pigs, a cross between Landrace and Yorkshire, weighing kg were used. They received humane care in compliance with the Guide for the Care and Use of Laboratory Animals published by the National Institutes of Health. They underwent conventional laparoscopic sterilization by bipolar electrocauterization of a 5-mm segment of the distal portion of each uterine horn, where the lumen is approximately 3 mm in diameter. The pelvic structures were normal in all the pigs. All the animals survived this first surgery and were allowed to convalesce for 2 weeks. Reanastomosis was performed laparoscopically 2 weeks later by three laparoscopic surgeons with no previous experience in human laparoscopic tubal microsuturing. Surgeon A had the most experience with the robotic arms before the animal trial. He had performed robotic surgery on six animals and had more than 40 hours of practice in the dry laboratory area. Surgeon B had approximately six hours of practice with the robotic device in the dry laboratory and no animal experience. Surgeon C had performed robotic surgery in one animal and had approximately 15 hours of practice in the dry laboratory. Each surgeon performed surgery on two pigs (4 anastomoses). The Zeus system (Computer Motion Inc.) incorporates three robotic arms, allowing a single surgeon to manipulate remotely the laparoscopic camera and two laparoscopic surgical instruments simultaneously with enough stability to perform extensive suturing maneuvers under laparoscopic magnification. The surgeon directs the position of the camera by a foot pedal or voice activation. The movement of the robotic arms is controlled with two handles. These handles are housed in a mobile console that can be positioned anywhere in the operating room. The surgeon operates in front of a monitor while seated in an armchair away from the surgical table. Manipulation of the robotic handles is transmitted to a computer controller that filters, scales, and then translates the surgeon s movements to the robotic arms and instrumentation. There is no measurable delay between the movement of the robotic handles on the console and movement of the instruments in the patient. Movement can be scaled according to the surgeon s specifications. For example, a scaling ratio of 15:1 means that for every 1 inch the surgeon moves the handles at the console, the robotic surgical instruments would move 1/15 inch at the surgical site. Tremors and small unintended hand motions that are the result of holding instruments for a prolonged period are eliminated. Thus, the instruments are held in a steady manner throughout the procedure. The three robotic arms were fixed to the sides of the surgical table by an engineer, and the operating field was prepared and draped in a sterile manner. Four trocars were placed in the umbilicus, both lower abdominal quadrants, and suprapubically (Fig. 1). Pneumoperitoneum with CO 2 was maintained at 12 mm Hg with a pressure-controlled insufflator. A Foley catheter was secured in the vagina with a purse string suture for chromotubation to assess patency at the completion of the anastomoses. Intravenous cefazolin was administered preoperatively for prophylaxis in both procedures. The laparoscope was attached to the foot-controlled robotic arm. The previously cauterized uterine horn segments were excised. The needle driver and grasper (Karl Storz Endoscopy, Inc., Culver City, CA), fashioned after the Szabo-Berci instruments, were placed through the lateral ports and fastened to the Zeus robotic arms. These instruments are 3 mm in diameter and were introduced through the 5-mm trocars in each lateral lower quadrant. The suprapubic trocar was used to insert, retrieve, and cut sutures with conventional laparoscopic instruments. FERTILITY & STERILITY 531

3 FIGURE 2 The surgeon is able to adopt a comfortable position while performing laparoscopic anastomoses with robotic assistance remote from the operative field. TABLE 1 Mean operative times for robotic tasks in laparoscopic microsurgical uterine horn anastomosis. Task Mean ( SD) time (min) Robotic arm set-up Robotic arm draping Robotic arm instrument set-up Robotic anastomoses (left horn) Robotic anastomoses (right horn) Dismantling the robotic arms Total operating time* * Includes laparoscopic set-up time and preparation of uterine horns for anastomosis. All procedures except the microsuturing were performed by conventional laparoscopic techniques without robotic assistance. All these tasks were performed by a scrubbed surgical assistant. The surgeon was seated on a chair with arm rests and operated while viewing a television monitor remote from the operating table (Fig. 2). The right and left robotic handles controlled the movements of the needle driver and grasper, respectively, and the foot pedal controlled the position of the laparoscope and video camera. The necrotic area where the tubal sterilization had been performed was excised, and the edges were trimmed to reach healthy tissue. The left horn was always reanastomosed before the right horn. An 8-cm-long 7-0 polypropylene suture with a curved needle was introduced into the peritoneal cavity through the suprapubic port for the anastomosis. All microsuturing was performed with the robotic device. Large defects in the mesosalpinx were approximated to reduce tension and facilitate the placement of subsequent sutures. The first suture in the uterine horn was placed at the 6 o clock position. The next suture was placed at 12 o clock and cut long enough for traction on this suture to aid in the placement of the 3 o clock and 9 o clock sutures. All sutures were full thickness to include the serosa, muscularis, and mucosa in such a way that the knot could be tied extraluminally. All the sutures were tied with three throws for each knot, using the intracorporeal technique. Anastomosis patency was confirmed by chromotubation with indigo carmine. Depending on the lumen diameter and whether a gross leak was seen on chromotubation, an additional suture was placed. At the end of the procedure, the surgeon ranked his fatigue according to the following choices: none, mild, moderate, and severe. They also were asked to describe any other discomfort. The animals were given oral ampicillin for the first 3 postoperative days. They were observed in the animal facility for the next 4 weeks for loss of appetite, abdominal distention, bowel movements, decreased activity, and wound infection. They then were killed by euthanasia, and the pelvic cavity was examined for evidence of traumatic injury related to the use of the robotic instrumentation. Tubal patency and intraabdominal adhesions were evaluated. The uterine horns, oviducts, and ovaries then were resected en bloc. The uterine horns were fixed at room temperature with use of a perfusion fixation technique under 50 cm of hydrostatic pressure with 2% glutaraldehyde in 0.1 M phosphate buffer with 3% sucrose. The anastomosis sites then were incised longitudinally. Slides were prepared for histologic study after appropriate paraffin embedding and staining. RESULTS All animals survived both surgeries without any intraoperative or postoperative complications. Bilateral uterine horn anastomosis was accomplished in all animals. All 12 anastomoses (2 per pig) were patent at the completion of the surgery. The operative times associated with the robotic task are shown in Table 1. The time required for anastomosis was recorded from the time the needle on the needle driver was ready to be placed through the tissue until the third throw of the final knot was completed. Eight anastomoses required four stitches to complete. The four remaining anastomoses required five stitches to make an adequate closure. No injuries related to the use of the robotic system occurred. At necropsy 4 weeks later, 8 of 12 (67%) anastomoses were patent, and only one pig had both anastomoses occluded. There was evidence of moderate intraabdominal adhesions in 1 pig and minimal peritubal adhesions in two additional animals. The surgeons reported only mild fatigue but did complain of thumb numbness as well as hand and wrist pain at the end 532 Margossian et al. Robotically assisted microanastomosis Vol. 70, No. 3, September 1998

4 TABLE 2 Anastomosis time for each uterine horn. Surgeon Anastomosis time (min) Pig 1 Pig 2 Left horn Right horn Left horn Right horn A B C of the surgeries. The mean performance time per anastomosis did not significantly differ between the three surgeons (by Student s t-test) (Table 2). The robotic device functioned safely, and we did not have to break sterile technique at any time. With prolonged use of the robotic device, minor mechanical malfunctions occurred, such as loosening of the grasping function of the needle holder and grasper. This particular difficulty required us to repeatedly readjust the cable link to the robotic arms during the procedure. Although such minor malfunctions were somewhat annoying, they did not significantly increase operative time. DISCUSSION Essentially two types of robots are used to perform complex tasks. Industrial robots that perform a preprogrammed repetitive, high speed, precise task and teleoperated robots that mimic the movements of a human operator. An example of the latter would be the type of robot used for bomb deactivation. The particular robotic system we used in this experiment is a combination of both these systems. Robotics have been used in other medical specialities. In stereotactic neurosurgery, a computed tomography scanner is used to scan the brain before and during needle biopsy (9). However, except for simple biopsies, the technology is used for localization or navigation rather than for performing a procedure. Thus, the neurosurgeon has accurate knowledge of where the pathology is and how to reach the site but must perform the surgical task with conventional instruments. Previous studies on robotic applications in laparoscopic surgery dealt with the camera control (10). This is the first animal survival experiment using a robotic device for performing a laparoscopic surgical procedure. Although we used a foot-controlled robotic arm to manipulate the laparoscope, the Zeus system uses a speech recognition process that is speaker dependent. Each person who will use the system provides several examples of each command, and voice models are then constructed. A recent review examines this system in depth (10). Laparoscopic tubal anastomosis is a long, difficult, and exhausting procedure. Initial reports cited low pregnancy rates and prolonged operative times compared with standard open microsurgery (2 4). The robotic system was a substantial help in performing laparoscopic microsurgical anastomoses. It filters the surgeon s tremor and scales movements according to the surgeon s specifications. This results in smooth, precise surgical maneuvers with reduced fatigue and added stability and comfort during the procedure. Back and neck stiffness are common complaints of endoscopic surgeons, particularly with intracorporeal suturing. In our experience, back and neck stiffness, hand cramps, and wrist stiffness were significant only after prolonged use of the robotic handles. The robotic device functioned safely without compromising sterility or interfering with nursing or anesthesia activities or other surgical instrumentation. The robotic system was easy to install and remove. The minor technical problems encountered should be resolved in future prototypes. Although this was our initial experience in performing robotically assisted laparoscopic microsurgical anastomosis in a live animal model, the mean operative times were consistent with that of conventional open microsurgery for tubal anastomosis. Newer prototypes of Zeus already have incorporated useful changes. Cables are no longer required between the console where the surgeon sits and the robotic arms. Tactile feedback has been introduced to provide the surgeon with a sense of touch when grasping tissue. This feature will allow the surgeon to feel the tissue and make handling of tissue less traumatic. This first animal survival study has shown that laparoscopic, robotically assisted microanastomosis can achieve a high rate of patency. Research in the field of medical robotics is moving at a rapid pace with potential applications in gynecologic surgery. Acknowledgments: We thank Laurel Stevens, R.N., for coordinating the data collection. References 1. Vital and Health Statistics, Centers for Disease Control and Prevention/ National Center for Health Statistics. Fertility, family planning, and women s health: new data from the 1995 National Survey of Family Growth. 1997;19: Gomel V, Rowe TC. Microsurgical tubal reconstruction and reversal of sterilization. In: Wallach EE, Zacur HA, editors. Reproductive Medicine and Surgery. St. Louis: Mosby, 1995: Reich H. Laparoscopic tubal anastomoses. J Am Assoc Gynecol Laparoscopists 1993;1: Katz E, Donesky BW. Laparoscopic tubal anastomosis: a pilot study. J Reprod Med 1994;39: Dubisson JB, Swolin K. Laparoscopic tubal anastomosis (the one stitch technique): preliminary results. Hum Reprod 1995;8: FERTILITY & STERILITY 533

5 6. Yoon TK, Sung HR, Cha SH, Lee CN, Cha KY. Fertility outcome after laparoscopic microsurgical tubal anastomosis. Fertil Steril 1997;67: Sackier JM, Wang Y. Robotically assisted laparoscopic surgery. Surg Endosc 1994;8: Garcia-Ruiz A, Smedira NG, Loop FD, Hahn JF, Miller JH, Steiner CP, et al. Robotic surgical instruments for dexterity enhancement in thoracoscopic coronary artery bypass graft. J Laparoendoscop Adv Surg Tech 1997;7: Apuzzo ML, The Richard C. Schneider Lecture. New dimensions of neurosurgery in the realm of high technology: possibilities, practicalities, realities. Neurosurgery 1996;38: Sackier JM, Wooters C, Jacobs L. Robotic s application in surgery. Am J Surg 1997;174: Margossian et al. Robotically assisted microanastomosis Vol. 70, No. 3, September 1998