EFFICACY OF ESD IN LESIONS LOCATED IN DENTATE LINE. A PROSPECTIVE MULTICENTRIC COMPARATIVE STUDY

Aims:

Endoscopic submucosal dissection (ESD) is a well-established treatment for complex colorectal lesions. However, those which involve the dentate line (DL) up to 1 cm, have been traditional treated by transanal endoscopic microsurgery (TEM). Poor manoeuvrability and the presumable risk of bleeding might become ESD more difficult and unfeasible. Therefore, the lack of prospective comparative studies of ESD with this indication, makes it questionable.

Methods:

All rectal lesions from the Spanish registry of ESD resected from January 2016 to November 2018 were prospectively included. Lesions involving the DL (from anal verge to 1 cm) were compared with those located in upper portions of the rectum (from 1 cm to 15 cm).

Results:

159 rectal lesions resected by ESD were prospectively included. Of those, 46 (28.9%) involving DL and 113 (71.1%) were located in proximal portions. Both groups have similar size (DL 34.35 mm vs. NoDL 30.38 mm; p 0.056) and shape (LST-G homogeneous) (DL 9.8% vs. NoDL 17.3%; p 0.25). All lesions showed the same findings in terms of fibrosis (F2; DL 21.7% vs. 21.4% NoDL; p 0.82). Manoeuvrability was equivalent regardless the location (Good in DL 63.4% vs. No DL 71.7%; p 0.42). In terms of efficacy, ESD showed slightly higher rates of en bloc resection in No DL group (80.4% vs. 73.9%; p 0.37). However, R0 rates were quite similar (DL 63% vs. NoDL 71.4%; p 0.31). Regarding the adverse events, delayed bleeding was 2 fold higher in the DL group (19,6% vs. 8.8%; p 0.05). One perforation occurred in the DL group.

Conclusions:

ESD shows to be effective in lesions which involve the DL, with similar results in terms of en-bloc and R0 resection compared with ESD in other rectal areas. However, this location could be a risk factor for delayed bleeding.