Per Oral Transgastric Endoscopic Surgery (POTES): Laparoscopy Interface

Abstracts

T1381 Histologic, Anatomic & Physiologic Remodeling of the Porcine Stomach After Full-Thickness Plication with an Implanted Titanium Compression Device Jack Ramage Jr, Christopher J. Gostout, Charles S. Termin, Robert Sixto, Suzanne Thompson, Jonathon Coe Background: Endoscopic full-thickness plication of the porcine gastric cardia has been shown to effect gastric yield pressure. No studies have explored the histiologic or anatomic changes. Aim: To assess qualitative histiologic & anatomic changes and quantitative gastric yield changes induced by a novel, user-friendly titanium implantable plication device. Methods: Four 35 kg pigs, under general anesthesia, had titanium compressive implants placed endoscopically to create a full-thickness gastric cardia plication along the anterior surface. Radio-opaque markers were placed into either side of the plication to monitor for tissue displacement during healing. Tissues were harvested after endoscopic & fluoroscopic exams were performed at 6, 8 & 21 days post implant in two pigs, 43 days in one pig & 90 days in one pig. Separately, baseline and post endoscopic plication gastric yield pressures were measured in 22 excised porcine stomachs. Results: Fluoroscopic f/u exams showed no relative position changes of markers or titanium implant. Gross histiologic examination showed tissue within plication to be completely replaced by dense scar tissue. A capsule of scar tissue surrounded the implant. The overlying gastric mucosa was healthy without inflammation. The peritoneal surface overlying the plication was completely healed over in a uniform single layer. Microscopically there was mild inflammation immediately adjacent to the implant with an acellular matrix & leukocytes surrounded then by a leukocytic infiltrate. Fibroblasts & collagen fibers encapsulated the device & replaced the serosal and mucosal tissue of the apposed full thickness gastric walls between the plates of implant. Ex-vivo specimens showed an increase of mean baseline gastric yield pressure of 0.84 inches of water to a mean of 7.64 post implantation (p ! 0.05). Conclusion: A full thickness plication is retained up to 90 days with healing as confirmed by radio-opaque markers. Implant compression causes a remodeling of apposed gastric wall elements, especially the serosa and muscularis propria into scar tissue consisting of fibroblasts & collagen. The implant produces significant increases in gastric yield pressure in the ex-vivo pig model.

T1383 Per Oral Transgastric Non Anatomical Segmental Liver Resection Using Flexible Endoscope Venkat Rao, Manu Tandan, Sandeep Lakhtakia, Rupa Banerjee, Nageshwar Reddy Introduction: Per oral trans gastric peritoneoscopy has shown great promise both in the porcine and avian models. Diagnostic transgastric peritoneoscopy, liver biopsy were performed safely. Aim: To perform Per Oral Transgastric non anatomical segmental liver resection under laparoscopic control to assess the feasibility and safety in porcine model. Methods and Results: After creating pneumoperitoneum, a 0 degree laparoscope was passed through a transparietal abdominal trocar for laparoscopic vision. A double channel forward viewing endoscope was passed orally into the stomach. A wire guided needle knife was used to make the initial gastric puncture on the anterior gastric wall into the peritoneal cavity. The needle knife was withdrawn keeping the guide wire in position. The tract was dilated using a 12 mm CRE balloon. The scope was then railroaded along with the balloon over the guide wire into the peritoneal cavity. The balloon was deflated and the guide wire balloon assembly withdrawn. The abdominal viscera were examined by the passage of the endoscope in different directions aided the wheel movements. The liver was examined with the endoscope in retroflexion. A rotatable snare was passed through the right biopsy channel and a grasping forceps through the left biopsy channel. The opened snare was apposed to the edge of the liver. The grasping forceps was passed through the loop of the snare, the edge of the liver held and withdrawn into the snare. The snare was closed and using coagulation current a segment of the liver was excised. The cut edge of the liver was completely coagulated. There was no significant bleed from the resected liver margin. The procedure was repeated excising further segments of the liver. The resected specimens were extracted through the gastrotomy and perorally. The gastric rent was apposed with clips. The entire procedure was done under continuous laparoscopic vision documenting the safety of the technique. The procedure was done in two porcine models which were subsequently euthanised. Conclusion: Peroral trans gastric non-anatomical segmental liver resection is feasible and can be safely performed in porcine model.

T1382 Per Oral Transgastric Endoscopic Surgery (POTES): Laparoscopy Interface Venkat Rao, Manu Tandan, Sandeep Lakhtakia, Rupa Banerjee, Nageshwar Reddy Introduction: Per oral trans gastric peritoneoscopy and advanced procedures are feasible and performed in avian and porcine models. The safety of these procedures was of concern. Aim: To document the transgastric procedures in porcine model under simultaneous laparoscopic vision to confirm the safety. Methods and Results: The porcine model was anaesthetized using general anaesthesia and monitored. Pneumoperitoneum was created using closed technique with a veress needle. 11 mm trocar introduced transparietally and a 10 mm laparoscope (0 degree and 30 degree) was introduced to visualize the peritoneal cavity. Various transgastric procedures were done under laparoscopic control. Trans gastric peritoneal access through the anterior gastric wall was done using needle knife and CRE balloon dilator. The procedures were carried out using double channel endoscope, standard endoscopic accessories and diathermy. Pneumoperitoneum was maintained using CO2 by the insufflator which is connected to the biopsy channel of the endoscope by a Y connector. Advanced procedures including Liver biopsy (2), tubal ligation (2), Salpingectomy (1), gastrojejunostomy (2), Non anatomical liver resection (1) were done. All the procedures were done successfully and there were no major operative complications associated with the procedures. All the animals were euthanised after the completion of the procedures. Conclusions: Per oral transgastric access is an alternative approach for peritoneoscopy. The safety of the various advanced transgastric procedures was documented under laparoscopic control confirming the feasibility and safety of the procedures in porcine animal models.

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T1384 Colonoscopic Polypectomy in Retroflexion Douglas K. Rex, Mouen Khashab Background: Large sessile colon polyps present difficulty for endoscopists, because they are associated with the greatest risk from endoscopic resection, and because resection is time consuming, costly and technically difficult. One factor that creates technical difficulty is when all or a portion of the polyp is hard-to-access endoscopically. Little has been written about the value of retroflexion in the removal of hard-to-access large sessile colon polyps proximal to the rectum. Methods: We recorded the frequency with which retroflexion was needed in the removal of 59 consecutive sessile colon polyps 2 cm or larger located proximal to the rectum. All 59 polyps were removed using prototype colonoscopes with short bending sections that facilitate retroflexion. Results: Fourteen polyps were removed entirely (n Z 4) or partially (n Z 10) in retroflexion. Polyps that were removed in retroflexion were more likely to have been referred by another colonoscopist (14/49) compared to those initially discovered by the author during screening or diagnostic colonoscopy (0/10; p Z 0.05). There were no perforations and no complications related to retroflexion. Conclusions: Retroflexion is a useful adjunctive procedure for removal of some large sessile colon polyps proximal to the rectum that are difficult to access endoscopically. This may be particularly true in a colonoscopic practice that accepts referrals of polyps from other endoscopists.

Volume 61, No. 5 : 2005 GASTROINTESTINAL ENDOSCOPY AB237