LONG-TERM OUTCOMES OF COLORECTAL ENDOSCOPIC SUBMUCOSAL DISSECTION IN DIFFICULT LOCATIONS: DENTATE LINE, ILEOCECAL VALVE AND CECUM

Aims Endoscopic resection at the perineal rectum extending to the dentate line (RTDL), ileocecal valve (ICV), and cecum is difficult. Aim to assess ESD outcomes in these locations.

Methods Prospective single center European study from January 2013 to November 2018. Consecutive superficial neoplasms >20 mm or with a positive no-lifting sign secondary to a previous resection in the rectum involving the dentate line (distal margin < 10 mm from the dentate line) (n.50) or proximally (n.92), ICV (n.27), cecum (n.67), ascending colon (n.118), were included. Outcomes were compared in adjacent segments. ESD was performed by the standard technique by an expert operator (prior case volume: 80). Residual rate was assessed after 12 months.

Results Tumor features and ESD outcomes are reported in the Table. Prevalence of scarring neoplasms was higher in rectal (15%) and ICV (19%) groups than other cases (mean 9%). No significant differences were observed in patient and neoplasm features. RTDL distal margin was at the squamous epithelium in 32 (64%) cases. Ileal invasion was observed in 8 (29%) ICV cases.

En bloc and R0 resection rates for RTDL and pelvic rectal tumors were not significantly different (82% and 76% vs. 89% and 82%, respectively). Residual rate was significantly higher in RTDL (12% vs. 0%, P=0.002). ESD en bloc, R0 and residual rates for ICV, cecal, and ascending colon tumors were not significantly different (88% and 78%, 83% and 83%, 90% and 90%, respectively).

Conclusions ESD for RTDL and cecal tumors shows lower en bloc resection rates compared to adjacent segments, but it was similarly feasible and safe regardless a higher scar prevalence. The narrowness of the perineal rectum and the nonlinear ICV anatomy are associated to clinically relevant residual rates, and follow-up within 12 months is advisable.