bilateral tubal ligation, cholecystectomy, and closure of the gastrotomy were performed. The experiment was divided into two parts. The first part included five ani ...
Surg Endosc (2007) 21: 1862–1865 DOI: 10.1007/s00464-007-9281-1 Ó Springer Science+Business Media, LLC 2007
Endoloop application as an alternative method for gastrotomy closure in experimental transgastric surgery D. Katsarelias Department of Surgery, Aretaieion Hospital, V. Sofias 76 avenue, 115 27, Athens, Greece Received: 10 October 2006/Accepted: 25 October 2006/Online publication: 4 May 2007
Abstract Background: Experimental studies investigating transgastric endoscopic surgery report closure of the gastric wall incision with clips. The author of this report describes endoloop placement as an alternative, equally efficient, faster method for gastrotomy closure. Methods: Eight female pigs with a mean weight of 30 kg were used. Abdominal endoscopic exploration and transgastric operations including hepatic biopsies, bilateral tubal ligation, cholecystectomy, and closure of the gastrotomy were performed. The experiment was divided into two parts. The first part included five animals, which were killed immediately after the procedure. The second part included five animals, which were kept alive and killed 15 to 20 days later. Results: The first part of the experiment, performed for technical skills acquisition, involved transgastric abdominal exploration, liver biopsies, and bilateral tubal ligation, which were successful for all five animals. The gastric wall incision was closed by applying clips in four animals and endoloops in one animal. During the autopsy at the end of the experiment, the sites of intervention were examined macroscopically. In the second part of the experiment, gastrotomy closure with endoloop application was performed in two animals and with clip application in one animal. All three animals survived, gained weight, and demonstrated no signs of infection. They were killed 15 to 20 days after the procedure, and no signs of intraabdominal infection were found. Cultures from the peritoneal cavity were negative. At necropsy, macroscopic and microscopic examination confirmed complete healing of the gastrotomy. Conclusions: Transgastric endoscopic surgery is technically feasible and effective. The application of endoloops for closure of the gastric opening is a fast, easy, and equally safe alternative to clip placement.
Correspondence to: D. Katsarelias
Key words: Endoloop — Gastrotomy closure — Transgastric endoscopic surgery — NOTES — Transgastric cholecystectomy — Transgastric tubal ligation
In recent decades, endoscopic interventional techniques have been continuously evolving and expanding their fields of application [1, 2, 6]. Technology combined with endoscopistsÕ growing experience has led to an increasing number of interventions. Recent experimental reports on the transgastric approach to the abdominal cavity and on the performance of basic operative procedures describe the most innovative method used by endoscopists to minimize the invasiveness of surgical operations [1, 2, 11]. Because this approach represents an attractive new field in surgery, verification of the feasibility of the method represents a very important issue in relation to experimental animals and eventually humans. The procedures reported to date include transgastric abdominal exploration, fallopian tube ligation, cholecystectomy, splenectomy, transoral obesity surgery, gastrojejunostomy, and liver biopsy [3–5, 7–9]. In all experimental models reported, the common denominator is the gastric wall opening and its final closure. Interruption of the gastric wall and passage of the endoscope through the opening into the sterile abdominal cavity may result in septic complications that could compromise the application of the method. In addition, closure of the gastrotomy must be efficient, fast, and, above all, completely safe to avoid leakage that may lead to further and possibly more severe complications. To date, investigators have reported applying hemostatic clips for closure of the gastrotomy, with good results [4, 5, 7]. We used a porcine model for the application of the technique, and we report an alternative method for gastrotomy closure, the placement of three endoloops, with comparable results.
1863
Fig. 1. Schematic representation of the endoloop closure technique. a Left side. b Right side. c Third loop. d Final result.
Materials and methods The study was performed in the experimental laboratory of the Second Department of Surgery at the University of Athens, under the appropriate license of the veterinary authorities and in adherence to all international regulations for animal studies. Eight female pigs (Suis scrofis domesticus) with a mean weight of 30 kg (range, 25–35 kg) were used. All the animals were nourished regularly until 12 h before the experiment. After intramuscular injection of ketamine (4–6 mg/kg), atropine (0.5 mg/kg), and midazolam (0.75 mg/kg) for sedation, the animal was placed on the operating table, and an intravenous line was placed in the greater auricular vein. General anesthesia was administered (thiopental 4 mg/kg, fentanyl 3 mg/kg, and pancuronium 0.1 mg/ kg), and the animal was intubated. All the experiments were conducted using a standard sterile method. No blood products were given, and only crystalloids were administered throughout the experiment. Endoscopy of the upper gastrointestinal tract then was performed with a forward-viewing, double-channel therapeutic endoscope (GIF-2T160; Olympus, Tokyo, Japan) through a sterile overtube (Olympus). The stomach was copiously irrigated with povidone iodine solution, and an appropriate location on the anterior gastric wall was selected for the gastrotomy. A needle-knife sphincterotome (NK HPC-2 Wilson-Cook Medical inc., Winston-Salem NC, USA) was used to open the gastric wall layer by layer. Dilation of the gastrotomy with a common biliary balloon catheter (EBL-15-200 Wilson-Cook) was followed by passage of the endoscope into the abdominal cavity. Pneumoperitoneum was instituted and maintained, followed by complete exploration of the peritoneal cavity. After endoscopic orientation, the following operative procedures were performed: 1. Liver biopsies using a hot biopsy forceps (FD-1L-1; Olympus). 2. Bilateral tubal ligation with endoloop application (endoloop, MAJ254; Olympus). 3. Cholecystectomy with traction of the gallbladder using a grasping forceps (FG-49L-1; Olympus), ligation of the cystic duct and artery using a reusable clip applier (HX-5LR-1; Olympus) and long clips (Hx- 600-0904; Olympus), and finally, dissection of the gallbladder using the needle-knife sphincterotome, exchanging channels as
necessary. Hemostasis was obtained by means of a coagulation probe with a nozzle (1025052 MTW, Wesel, Germany). 4. Closure of the gastric wall incision with clips, as reported previously [4, 5, 7], or with endoloop placement. Clips were placed by means of a reusable clip applier using long clips. Endoloop closure proceeded as follows. The grasping forceps were passed through the first working channel of the endoscope, and the endoloop was passed through the other channel. With the aid of the forceps, the incisional margin was grasped in its center, elevated, and looped, with care taken to include all layers except the serosa. This was repeated on the opposite side of the incision by exchanging channels. The two loops were grasped and elevated, and a third loop was applied encompassing the entire length of the incision and tied down. In essence, the first two loops served as ‘‘anchors’’ for the third, which was an actual ‘‘closing’’ loop encompassing at the same time the most important layers of the gastric wall. The technique used for the gastrotomy closure is schematically shown in Fig. 1a–d. During the first part of the experiment, the gastrotomy was closed with clips in four animals and endoloops in one animal (Fig. 2). This was followed by exploratory laparotomy and macroscopic control of all operative sites. In the second part, intravenous antibiotics and analgesics (nonsteroidal antiinflammatory drugs [NSAIDS]) were administered to three animals immediately before the procedure and on the first postoperative day. The gastrotomy was closed with endoloops in two of the animals and with clips in one animal. All three animals survived and remained under observation on the premises of the experimental laboratory for 15 to 20 days. They were placed on a liquid diet for the first 2 postoperative days, then put on a regular diet thereafter. The animals were killed 15 to 20 days later using thiopental 5 mg/kg, pancuronium 0.1 mg/kg, and 3 ampules (1 amp = 13.9 meq) of potassium chloride (KCl). The gastric wall was evaluated endoscopically and during laparotomy to verify the results of the experiment and to compare loop and clip closures. All operative specimens were sent to pathology for microscopic examination, and all experiments were recorded. Data concerning operative time, technical details, and complications of each procedure were reviewed after the completion of each experiment.
1864
Fig. 3. Endoloop closure showing macroscopic findings at autopsy.
Fig. 2. Endoscopic view of closure site with endoloops in place.
Results The first five animals were used for the acquisition of technical skills, then killed at the end of the experiment. The three animals that survived, in the second part of the experiment, gained weight and showed no signs of septic complications. After 15 to 20 days, the animals were once again taken to the operating room, placed under anesthesia, and subjected to endoscopy, with no leakage evident. The site of the gastric opening was recognized as a well-defined ulcer at the terminal stage of the healing process. The endoloops or clips had fallen off the healed gastrotomy site except in one case, which still had one clip in place. Exploratory laparotomy then was performed. The anterior gastric wall, corresponding to the gastrotomy, was found closed, covered by a thin layer of greater omentum. No adhesions were found, and there was no pathologic fluid collection or abscess formation in the peritoneal cavity. Fluid samples from the abdominal cavity (right and left subdiaphragmatic area, right and left paracolic gutter, and pelvis) were collected and sent for cultures. All the results were negative. The operative sites, including the sealed gastrotomy, were examined macroscopically and subjected to pathology, which confirmed the complete closure of the gastrotomy site with no microscopic differences in the healing process between the two techniques (Fig. 3). The operative time for gastrotomy closure was calculated for all the animals included in the study. The mean procedure time was 34 min (range, 24– 46 min) for clip application and 15 min (range, 12–18 min) for loop application. Discussion Transgastric surgery is a new and attractive method for performing abdominal operations, and many investiga-
tors have reported the feasibility of proceeding with the method at an experimental level [4–7, 9]. Although it still is too early to determine the applicability of the method to humans because the necessary data still are missing, the various technical issues concerning the operative field per se and the various problems relative to the gastric barrier are of major interest. Sterility and avoidance of postoperative problems related to sepsis are important issues. Different methods for gastric and endoscope sterility have been proposed [3–5]. Some authors report positive abdominal cultures and intraabdominal abscesses [5], in part because of breaks in the sterilization technique and in part because of defective gastric closure, as reported by Wagh et al. [12]. Because the latter represents a major problem to be overcome before application of the method to humans, we strongly believe that the faster and more complete the closure of the gastric opening, the less the probability that septic complications will occur. During the first part of this experimental study, we identified two factors causing a delay in gastric closure. The first was our lack of experience at the beginning of the experiments while becoming acquainted with a new technique. The second factor was the shift in position of the gastric wall because optimal distension by means of endoscopic air insufflation was not feasible. In addition, the clips used (long clips) were initially designed for hemostasis and did not offer a safe and fast closure, especially in the case of an edematous gastric wall opening. This technical difficulty has been reported by other authors as well [12]. Currently, various investigators are focusing their interest on the development of new suturing devices for safe closure of the gastric wall [3, 10]. These devices frequently are complicated, difficult to handle, and often were not available to us. The problems we encountered caused significant time loss and prompted us to try a new method for closure that involved applying endoloops to the gastrotomy of the last animal in the first part of the study and verifying the air and water tightness of the closure.
1865
After loop placement, it was obvious that no air leak was present when the stomach was successfully distended. At laparotomy, the specimen was immersed in water, with no signs of water leakage. We observed that the time required for closure of the gastrotomy using the endoloop was significantly less than for clip closure. This fact (method) reduces the total time of the procedure. After these preliminary observations, we used the endoloop method to close the gastrotomy for last two animals in the second part of the experiment. Pathology confirmed the complete closure of the gastric opening, except for the outermost serosa layer, which was covered by omentum. Jagannath et al. [4] demonstrated that after balloon dilation of the entry site to gain peritoneal access, the gastric wall rapidly closes within minutes of endoscope withdrawal without requiring sutures or approximation of the opening. It seems that enclosure of all layers for closure of the gastrotomy site is not necessary. Endoloop application includes mainly the mucosal and submucosal layers of the gastric wall and occasionally the muscular layer. Our experience with natural orifice transluminal endoscopic surgery (NOTES) shows that the most important fact in gastrotomy closure is impermeability, even if the serosa of the gastric wall is not included. Conclusion In conclusion, we found that the mean time necessary for clip gastrotomy closure was longer than for endoloop closure. Additionally, the endoloop technique is as safe as clip application and technically more simple. Of course, more experience and familiarity with transgastric procedures must be obtained for evaluation of this new methodÕs possible advantages, which could make a small contribution in the effort to overcome drawbacks of the transgastric approach in the future.
References 1. Baron T (2003) Endoscopic drainage of pancreatic fluid collections and pancreatic necroses. Gastrointest Endosc Clin North Am 13: 743–764 2. Berger HG, Schwarz A, Bergmann U (2003) Progress in gastrointestinal tract surgery: the impact of gastrointestinal endoscopy. Surg Endosc 17: 342–350 3. Hu B, Chung SCS, Sun LCL, Kawashima K, Yamamoto T, Cotton PB, Gostout CJ, Hawes RH, Kalloo AN, Kantsenoy SV, Pasricha PJ (2005) Transoral obesity surgery: endoluminal gastroplasty with an endoscopic suture device. Endoscopy 37: 411–414 4. Jagannath SB, Kantsevoy SV, Vaughn C, Chung SS, Cotton PB, Gostout CJ, Hawes RH, Pasricha PJ, Scorpio DG, Magee CA, Pipitone LJ, Kalloo AN (2005) Peritoneal transgastric endoscopic ligation of fallopian tubes with long-term survival in a porcine model. Gastrointest Endosc 61: 449–453 5. Kalloo AN, Singh VK, Jagannath SB, Niiyama H, Hill SL, Vaughn CA, Magee CA, Kantsenoy SV (2004) Flexible transgastric peritoneoscopy: a novel approach to diagnostic and therapeutic interventions in the peritoneal cavity. Gastrointest Endosc 60: 114–117 6. Kaneko T, Akamatsu T, Shimodaira K, Ueno T, Gotoh A, Mukawa K, Nakamura N, Kiyosawa K (2005) Nonsurgical treatment of duodenal perforation by endoscopic repair using a clipping device. Gastrointest Endosc 50: 410–413 7. Kantsevoy SV, Hu B, Jagannath SB, Niiyama H, Chung SS, Cotton PB, Gostout CJ, Hawes RH, Pasricha PJ, Magee CA, Vaughn CA, Barlow D, Shimonaka H, Kalloo AN (2005) Endoscopic gastrojejunostomy with survival in a porcine model. Gastrointest Endosc 62: 287–292 8. Kantsevoy SV, Hu B, Jagannath SB, Vaughn CA, Beitler DM, Chung SSC, Cotton PB, Gostout CJ, Hawes RH, Pasricha PJ, Magee CA, Pipitone LJ, Talamini MA, Kalloo AN (2006) Transgastric endoscopic splenectomy: is it possible? Surg Endosc 20: 522–525 9. Park PO, Bergstrom M, Fritscher-Ravens A, Swain P (2005) Experimental studies of transgastric gallbladder surgery: cholecystectomy and cholecystogastric anastomosis (videos). Gastrointest Endosc 61: 601–606 10. Pham BV, Raju GS, Ahmed I, Brining D, Chung S, Cotton P, Gostout CJ, Hawes RH, Kalloo AN, Kantsevoy SV, Pasricha PJ (2006) Immediate endoscopic closure of colon perforation by using a prototype endoscopic suturing device: feasibility and outcome in a porcine model (with video). Gastrointest Endosc 64: 113–119 11. So JB, Chiong EC, Chiong E, Cheah WK, Lomanto D, Goh P, Kum CK (2002) Laparoscopic appendectomy for perforated appendicitis. World J Surg 26: 1485–1488 12. Wagh MS, Merrifield BF, Thompson CC (2006) Survival studies after endoscopic transgastric oophorectomy and tubectomy in a porcine model. Gastrointest Endosc 63: 473–478
