Standard diagnostic laparoscopy is superior to NOTES approaches: results of a blinded, randomized controlled porcine study.

BACKGROUND AND STUDY AIM: The use of transluminal endoscopic access via the stomach or colon for flexible diagnostic peritoneoscopy has been proposed, although the diagnostic value of the technique has not yet been fully clarified. In this animal trial, the two main natural orifice transluminal endoscopic surgery (NOTES) approaches - transgastric (TG) and transcolonic (TC) - were compared with standard transabdominal access using both rigid (TAR) and flexible instruments (TAF) for diagnostic laparoscopy. METHODS: A total of 48 peritoneoscopies were performed using two randomly assigned approaches in 24 anesthetized pigs. The ability of the examinations to detect 576 electrocautery markings simulating intraperitoneal metastases, to achieve complete organ visualization, and to simulate organ biopsies was analyzed. RESULTS: Sensitivities for the detection of lesions were 78.5 %, 59.7 %, 48.6 %, and 38.9 % for TAR, TAF, TC, and TG, respectively; standard laparoscopy was superior to all other approaches (P < 0.01). Among the NOTES approaches, TC was superior for examining the upper abdomen (P = 0.03). Complete organ visualization was better with the transabdominal approach (visual analogue scale TAR 7.15, TAF 6.71) than with the NOTES access routes (TC 5.07, TG 4.35); standard rigid laparoscopy was superior to both NOTES approaches (P < 0.01). Organ biopsy simulation was possible in 87 %, 85 %, 72 %, and 65 % of cases with TAR, TAF, TC, and TG, respectively. Standard rigid laparoscopy was again superior to both NOTES approaches (TAR vs. TC, P = 0.03; TAR vs. TG, P < 0.01). CONCLUSIONS: In this experimental trial, rigid standard laparoscopy provided better organ visualization, better lesion detection, and better biopsy capability than the transgastric and transcolonic NOTES approaches. In its current form, NOTES appears to be unsuitable for diagnostic laparoscopy.

Endoscopic mucosal resection using a grasp-and-snare technique.

BACKGROUND AND STUDY AIM: Endoscopic mucosal resection (EMR) is a minimally invasive method for en bloc removal of superficial gastrointestinal lesions. The aim of this study was to evaluate the feasibility of a novel grasp-and-snare EMR technique. METHODS: In 10 domestic pigs, gastric lesions of approximately 3 cm were marked using electrocautery. EMR was performed using a double-channel endoscope. A novel tissue anchor was used through one channel, and a monofilament snare through the other. After submucosal injection, a circumferential mucosal incision was created. The tissue-anchoring device was then advanced through the open snare and anchored into the submucosal layer. The tissue-anchoring device was partly retracted into the endoscope and the snare was positioned into the circular incision. The snare was subsequently closed and the specimen resected by applying high-frequency electrocautery. RESULTS: Mean time to perform EMR was 32.4 minutes (range 22-41 minutes, SD 6.3). EMR yielded specimens that ranged in area from 2.7 cm (minor axis) by 2.8 cm (major axis) to 4.0 cm by 4.2 cm (mean area 9.36 cm(2); range 5.94-13.19 cm(2); SD +/- 2.50). Complete en bloc resection including all electrocautery markings was achieved in 9/10 cases. In one case, resection was achieved in two steps. One gastric wall perforation occurred. No other adverse events were observed. CONCLUSIONS: Grasp-and-snare EMR is feasible in an animal model. The technique can be performed efficiently compared with standard methods. To avoid perforation, caution is needed to ensure that tissue anchor needles are placed within and not deeper than the submucosal layer prior to tissue retraction.

Endoscopic closure of large colonic perforations using an over-the-scope clip: a randomized controlled porcine study.

BACKGROUND AND STUDY AIMS: Perforation of the colon is considered to be one of the most serious complications of flexible endoscopy. The over-the-scope clip system (OTSC) has previously been shown to close small colonic perforations effectively. The aim of this randomized controlled porcine study was to compare acute closure strengths between the novel 11-mm over-the-scope-clip and surgical closure for large colonic perforations. MATERIAL AND METHODS: In 24 anesthetized domestic pigs, an 18-mm sigmoid perforation was created endoscopically using a needle knife and dilating balloon. The animals were randomly assigned to undergo either open surgical repair (n = 12) or endoscopic closure using the OTSC system (n = 12). Pressurized leak tests were performed during necropsy. RESULTS: Mean time to perform the incision in the sigmoid colon and obtain peritoneal access was 5.5 minutes (range 3-12; SD +/- 2.5). Mean time for endoscopic closure was 6.8 minutes (range 3-14; SD +/- 3). At necropsy, all OTSC and surgical closures demonstrated complete sealing of colotomy sites. In one case peritoneum and in a second case adjacent small intestine were found incorporated into the OTSC closure. No other complications occurred. Pressurized leak tests revealed a mean burst pressure of 62.8 mmHg (range 18-112; SD 35.7) for OTSC closures and 67.4 mmHg (range 30-90; SD 19) for sutured closure. No significant differences in burst pressures were noted between the OTSC closures and surgical repair. CONCLUSION: Closure of acute perforations using the OTSC system is comparable to surgical closure in a nonsurvival porcine model.