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Short-term outcomes following endoscopic submucosal dissection of large protruding colorectal neoplasms.

BACKGROUND
Although submucosal dissection is useful for treating laterally spreading colorectal tumors, there is little information regarding the endoscopic treatment of large protruding colorectal neoplasms. Here, we aimed to evaluate the clinical outcomes of endoscopic submucosal dissection for protruding colorectal neoplasms ≥ 20 mm in diameter.


METHODS
In total, 112 consecutive patients undergoing treatment between January 2005 and June 2017 were enrolled retrospectively. The study period was divided into six periods to evaluate any changes in outcomes over time. We reviewed all short-term clinical outcomes, including lesion characteristics, procedure time, and percentages of en bloc resection, curative resection, adverse events, and treatment discontinuation.


RESULTS
The percentages of en bloc, en bloc R0, and en bloc curative resections were 88 %, 82 %, and 59 %, respectively. Perforation occurred in 11 patients (10 %), and the endoscopic procedure was discontinued in five patients (4 %) because of technical difficulty. For lesions ≥ 40 mm in diameter, the procedure time showed a statistically significant decreasing trend in the latter half of the study period. However, the rate of cure did not improve along with enhancements to the procedure's technological aspects.


CONCLUSIONS
Although endoscopic submucosal dissection for large protruding lesions has advanced in terms of its technical aspects, its ability to cure large protruding neoplasms has not shown gratifying results.