Effectiveness and safety of endoscopic submucosal dissection using the pocket creation method in the Japanese population: a systematic review and meta-analysis.

Endoscopic submucosal dissection (ESD) is a standard method for minimally invasive resection of superficial gastrointestinal tumors. The pocket creation method (PCM) facilitates ESD regardless of location in the gastrointestinal tract. The aim of this systematic review and meta-analysis is to evaluate the effectiveness and safety of ESD for superficial neoplasms in the upper and lower gastrointestinal tract comparing the PCM to the non-PCM. Randomized controlled, prospective, and retrospective studies comparing the PCM with the non-PCM were included. Outcomes included en bloc resection, R0 resection, dissection speed, delayed bleeding and perforation. Pooled odds ratios (ORs) with 95 % confidence intervals (CIs) using the Mantel-Haenszel random effect model were documented. Eight studies including gastric, duodenal, and colorectal ESD were included. The en bloc resection rate was significantly higher in the PCM group than the non-PCM group (OR 3.87, 95 %CI 1.24-12.10  = 0.020). The R0 resection rate was significantly higher in the PCM group than the non-PCM group (OR 2.46, 95 %CI 1.14-5.30,  = 0.020). The dissection speed was significantly faster in the PCM group than the non-PCM group (mean difference 3.13, 95 % CI 1.35-4.91,  < 0.001). The rate of delayed bleeding was similar in the two groups (OR 1.13, 95 %CI 0.60-2.15, 0.700). The rate of perforation was significantly lower in the PCM group than the non-PCM group (OR 0.34, 95 %CI 0.15-0.76, 0.009). The PCM facilitates high-quality, fast and safe colorectal ESD. Further studies are needed regarding the utility of PCM in ESD of the upper gastrointestinal tract.