Widespread EMR: a new technique for removal of large areas of mucosa.

BACKGROUND: Widespread EMR is a novel technique for resection of large areas of mucosa as a single bloc. Large lesion size (>2 cm) is a recognized limitation of current EMR techniques. This study assessed the technical feasibility, efficacy, and safety of widespread EMR in a porcine model. METHODS: Widespread EMR was performed in 6 pigs. A submucosal fluid cushion was created in the distal esophagus by using a 0.83% solution of hydroxypropyl methylcellulose. A mucosal strip 5 cm in length and including at least 50% of the luminal circumference was marginated by using a prototype cutting device. The proximal end of the mucosa was stripped from the submucosa by using a grasping forceps. The distal end was snare resected. Resected tissue was assessed histologically. Endoscopy was repeated at weeks 1 and 6. At week 6, a second widespread EMR of the mucosa on the wall opposite the initial resection was attempted to create a full circumferential resection. RESULTS: Widespread EMR was completed in all animals. The esophagus was denuded of mucosa in 5-cm lengths that included 50% of the circumference of the lumen. No procedure-related complication was observed. Histologic assessment demonstrated that the resection specimen included mucosa and submucosa but not muscularis propria. Endoscopy at 1 week revealed mucosal regrowth in two animals and ulceration in 4. At week 6, regrowth of mucosa was noted in all animals. The second wide EMR proved to be technically difficult and was associated with perforation, peri-esophageal abscess, and stricture formation. CONCLUSIONS: Wide EMR appears to be technically feasible for removal of large areas of mucosa. Mucosal strips 5 cm long that included over 50% of the luminal circumference were resected safely. Resection was followed by complete regrowth of the mucosa. However, a second wide EMR to create a circumferential resection proved to be technically difficult and unsafe.

Future opportunities and developments for endoscopic gastroesophageal reflux disease therapy.

Endoscopic treatments for gastroesophageal reflux disease are directed at specific targets at the gastroesophageal junction. We explore the limitations and challenges of the anatomy, how current methods alter the anatomy and then speculate on the direction of future therapies.

Understanding endoluminal gastroplications: a histopathologic analysis of intraluminal suture plications.

BACKGROUND: Endoluminal gastroplication is used to treat GERD, with modest results. Little is known of the histologic reaction to endosutures. Thus, the histologic response to intraluminal plications at different penetration depths within the gastric wall was studied in an animal model. METHODS: Intraluminal gastroplications were performed through a laparotomy in 18 New Zealand rabbits. Three sets of everted plications were placed at different penetration depths in each stomach: submucosa (SMpl), muscularis propria (Mpl), and serosa (Spl). Animals were randomized to survival times of 3, 10, or 60 days (respectively, Groups I, II, and III). Plications were compared with a grade scale for each histologic healing phase and gross inspection. RESULTS: Fusion between folds was absent in all groups. Serosa differed from muscularis propria with respect to the proportion of samples with microscopic ischemia (67% vs. 8%; p = 0.015), remaining sutures in Group III (33% vs. 3%; p < 0.05 in a single test of significance, but correction for multiple testing removes this significance), and remaining plications in Group II (96% vs. 54%; p < 0.05 in a single test of significance, but correction for multiple testing removes this significance). All of the total and partial histologic scores for the corresponding healing phase in each group escalated with penetration depth. Overall comparison of the histologic scores showed a significant difference among the plications in the proliferation (Group II, p = 0.004) and maturation (Group II, p = 0.009) phases. Total scores also differed among the plications in Groups II (p < 0.001) and III (p < 0.001). Plications were absent in all of Group III, with Spl resulting only in a flat scar. CONCLUSION: Everted intraluminal gastroplications do not result in fusion between folds irrespective of suture-penetration depth. A flat scar is the final outcome and appears proportional to the amount of ischemia, foreign body reaction, and suture depth.

Hydroxypropyl methylcellulose: A better submucosal fluid cushion for endoscopic mucosal resection.

BACKGROUND: Formation of a submucosal fluid cushion has become integral to endoscopic mucosal and polyp resection. Solutions available for injection into the submucosa of the GI tract create short-lasting submucosal fluid cushions or are costly. The feasibility, durability, and histologic response to submucosal fluid cushions created by injection of hydroxypropyl methylcellulose were studied in the esophagus of pigs. METHODS: Thirty-six esophageal submucosal fluid cushions created with hydroxypropyl methylcellulose were studied in 12 animals divided in 2 groups of 6 animals each. In Group I, 18 submucosal fluid cushions were created by submucosal injection of hydroxypropyl methylcellulose followed by tattooing. In Group II, 18 submucosal fluid cushions were created by submucosal injection of hydroxypropyl methylcellulose, with sites marked by an endoscopically placed suture. In all cases, the duration of the submucosal fluid cushion was measured. After 7 days, submucosal fluid cushion sites were assessed by EGD, necropsy, and histologic evaluation. RESULTS: The mean submucosal fluid cushion duration was 36 minutes (3-45 minutes) and 38 minutes (5-45 minutes) for, respectively, Groups I and II. EGD and necropsy after 1 week showed normal-appearing mucosa at the site of all submucosal fluid cushions in both groups. Some Group I animals additionally had nodules at the tattoo sites. Histologic assessment demonstrated minimal alterations in 33 of 36 (92%) submucosal fluid cushion sites and localized mild inflammatory reaction in 3 of 36 (8%). In Group I, 8 of 18 (44%) tattoo sites exhibited a significant inflammatory reaction, including 3 abscesses. CONCLUSIONS: Hydroxypropyl methylcellulose creates a long-lasting submucosal fluid cushion with minimal tissue reaction and should be considered a low-cost option for creating submucosal fluid cushions. The use of tattooing with carbon black should be carefully considered when histologic study is required to assess potential inflammatory tissue responses to an invasive technique or instillation of foreign material in the GI tract.