Risk Factors of Adverse Outcomes for Colorectal ESD After Generalization of the Technique—A Multi-Centre Retrospective Study in Hong Kong

Background: Most of the public hospitals in Hong Kong provide a regular colorectal endoscopic submucosal dissection (ESD) service. The current retrospective study aims to review the long- and short-term outcomes of these services, so as to identify areas for improvement. Method and Results: From January 2017 to March 2020, 634 lesions in 623 patients were removed by an ESD technique in seven endoscopic units. The mean lesion size was 31 mm (SD 13 mm, range 10–95 mm), and the mean procedure time was 121 min (SD 67 min). En bloc resection and R0 resection could be achieved in 91.3% and 79.3% of the lesions, respectively. The intra-procedure perforation rate was 12.3%. The delayed bleeding rate was 2.1%, and the delayed perforation rate was 0.8%. Only 0.9% (6/634) of the procedures needed emergency surgical salvage due to complications. Most of the lesions were adenomas (564/634), and 55 of them were adenocarcinomas. The cumulative local recurrence rate was 4.0% at a mean follow-up of 34 months. In multivariate analysis, longer procedure time, submucosal fibrosis, hybrid ESD and piecemeal removal were associated with intra-procedure perforation. Risk factors for failed en bloc resection included non-granular and polypoid morphology, colonic location, longer procedure time and low centre volume. Malignant pathology without salvage surgery was the only independent risk factor for local recurrence. Conclusions: Colorectal ESD has been carried out in Hong Kong with acceptable short-and long-term outcomes despite the technique still being in the learning phase in some centres. Potential areas for improvement should include targeted training to speed up the procedure and enable better handling of difficult cases, aiming to decrease the perforation rate and local recurrence.