Left colonic localization, non-granular morphology, and pit pattern independently predict submucosal fibrosis of naïve colorectal neoplasms before endoscopic submucosal dissection.

Background: Endoscopic submucosal dissection (ESD) represents the method of choice for removal of large colorectal neoplasms with suspected submucosal invasion. Presence and degree of submucosal fibrosis increases ESD duration and technical complexity, reduces the rate of curative resection and reduces safety profile. The aim of the study was to identify pre-procedural predictive factors of submucosal fibrosis in naïve colorectal neoplasms and to assess the impact of fibrosis on technical and clinical ESD outcomes.

Methods: All consecutive ESD performed between 2014 and 2021 were retrieved from a prospectively collected database. For each patient, pre-procedural, procedural, and post-procedural data were recorded. Logistic regression was used to identify pre-procedural predictive factors for submucosal fibrosis. The study was approved by Institutional Reviewer Board and registered on ClinicalTrials.gov (NCT04780256).

Results: One hundred-74 neoplasms (46.6% rectum, 21.8% left colon, 31.6% right colon; size 34.9 ± 17.5 mm) from 169 patients (55.0% male; 69.5 ± 10.4-year-old) were included. 106 (60.9%) neoplasms were granular type laterally spreading tumor (LST-G), 42 (24.1%) non-granular (LST-NG), and 26 (14.9%) sessile; invasive pit pattern was observed in 90 (51.7%) lesions. No fibrosis (F0) mild (F1) and severe (F2) were observed in 62 (35.6%), 92 (52.9%), and 20 (11.5%), respectively. Left colonic localization [OR 3.23 (1.1-9.31)], LST-NG morphology [OR 5.84 (2.03-16.77)] and invasive pit pattern [OR 7.11 (3.11-16.23)] were independently correlated to submucosal fibrosis. Lower curative resection rate (59.8% vs. 93.5%, P < 0.001) was observed in case of fibrosis; the incidence of adverse events was higher in case of severe fibrosis (35.5%) compared to no (3.2%) and mild fibrosis (3.3%; P < 0.001). Procedure time was significantly impacted by presence and degree of fibrosis (P < 0.001).

Conclusions: Left colonic localization, LST-NG morphology, and invasive pit pattern are independent predictors of fibrosis, affecting technical and clinical ESD outcomes. Pre-procedural stratification is pivotal to estimate procedure time, required operator's experience and advanced dissection techniques. Cecinato P et al. Left colonic localization, non-granular morphology, and pit pattern independently predict submucosal fibrosis of colorectal neoplasms before endoscopic submucosal dissection. Surg Endosc. 2023.