Comparison of ENDO CUT mode and FORCED COAG mode for the formation of stricture after esophageal endoscopic submucosal dissection in an in vivo porcine model

Stricture is a major complication of esophageal endoscopic submucosal dissection (ESD) for superficial esophageal carcinoma. To date, various methods have been developed to prevent stricture. However, the mechanism by which different electrosurgical unit (ESU) modes affect the formation of post-ESD stricture has not been evaluated. This study aimed to compare the degree of stricture caused by two major ESU modes (ENDO CUT mode and FORCED COAG mode) in a porcine model. Twelve ESD procedures covering half of the circumference were performed in six pigs. Mucosal incision was performed with a ball-tip flush knife and submucosal dissection was performed with a hook knife; the two modes used were ENDO CUT I (Effect 2, Duration 2, Interval 3) and FORCED COAG mode (Effect 3, 40 W) (VIO300D, ERBE Germany). The pigs were killed humanely 30 days after ESD, and the severity of stricture and fibrosis was assessed. The resected site of the esophagus showed complete mucosal regrowth and scar formation in all pigs. There was no significant difference between the two modes in procedure time and size of resected specimen (14.4 +/- 2.4 and 15.9 +/- 6.1 min, P = 0.589; 626 +/- 148, 661 +/- 186 mm(2), P = 0.74, respectively). Stricture rate and severity of fibrosis in the submucosal layer were significantly lower in ENDO CUT mode than in FORCED COAG mode (31.5 +/- 16.0% vs 44.3 +/- 11.6%, P = 0.046; 36.2 +/- 17.1% vs 60.4 +/- 26.8%, P = 0.024, respectively). ENDO CUT mode showed promising ability to attenuate fibrosis and stricture after esophageal ESD.