Underwater ESD Associated With Less Post-ESD Coagulation Syndrome in Retrospective Study

Underwater endoscopic submucosal dissection (U-ESD; typically performed with saline rather than water) has several potential advantages over conventional ESD (C-ESD; performed with carbon dioxide insufflation). First, U-ESD provides a heat sink effect that could reduce thermal injury to the muscularis propria. U-ESD also creates a tissue floating effect that increases the submucosal space, reduces or illuminates halation, and has a 1.33 optical zoom effect.

In a retrospective study of colorectal ESD, the absolute rate of post-ESD coagulation syndrome (PECS) was 1 of 78 patients (1.3%) who underwent U-ESD versus 11 of 115 patients (9.6%) who underwent C-ESD (P=.029). Patients with overt muscle injury or perforation were excluded.

Median dissection speed was faster in the U-ESD group at 11 mm^2/minute versus 7 mm^2/minute in the C-ESD group (P<.001).

Propensity score matching analysis was performed for age, sex, body mass index, antithrombotic use, lesion location, morphology, specimen size, submucosal fibrosis, histopathology, and procedure time. There were 54 matched pairs, and in this analysis, the PECS rate was 0% with U-ESD and 11.1% with C-ESD.