Efficacy and safety of endoscopic submucosal tunnel dissection for rectal laterally spreading tumors

Background Evidence that comprehensively compares the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) with endoscopic submucosal dissection (ESD) for rectal laterally spreading tumors (LSTs) is limited. Methods Between January 2009 and June 2018, 143 rectal LSTs in 143 patients who had undergone either ESD ( n = 84) or ESTD ( n = 59) were included in the study. One-to-one propensity score matching (PSM) was performed, and 50 pairs were selected. The data on patient demographics, treatment information, pathology reports, adverse events and follow-up were collected. Results Before PSM, the median specimen area was significantly larger in the ESTD group than in the ESD group (12.56 cm 2 vs. 6.32 cm 2 , respectively; p < 0.001). The median dissection speed was significantly higher in the ESTD group than in the ESD group (24.53 mm 2 /min vs. 15.16 mm 2 /min, respectively; p < 0.001). After PSM, the median dissection speed was significantly higher in the ESTD group than in the ESD group (23.80 mm 2 /min vs. 17.12 mm 2 /min, respectively; p < 0.001). In multiple linear regression analysis, significant factors related to a higher dissection speed were the treatment method of ESTD ( p < 0.001) and larger specimen area ( p < 0.001). Conclusions ESTD appears to be a safe and effective method to treat rectal LSTs. Compared with ESD, ESTD appears to achieve a higher dissection speed for rectal LSTs.