Predictive factors for complications in endoscopic resection of large colorectal lesions: a multicenter prospective study

Background and study aims: Conventional endoscopic resection (CER) includes polypectomy and endoscopic mucosal resection. The most common complications related to these techniques are post procedure bleeding and perforation. The aim of this study was to evaluate the outcomes of CER for colorectal neoplasms ≧20 mm and to clarify predictive factors for complications. Patients and methods: We conducted a multicenter prospective study at 18 specialized institutes. From October 2007 to December 2010, 1,029 CERs were performed at participating institutes. We collected the data prospectively and analyzed gender, age, tumor size, gross appearance, mode of resection, etc. Results: The mean size of polyps resected was 26.4 ± 8.6 mm (range 20–120 mm). The final pathology was Vienna classification category 1 or 2 in 24, category 3 in 502, and category 4 or 5 in 503 lesions. Post procedure bleeding and intra procedure perforation occurred, respectively, in 16 (1.6 %) and 8 cases (0.78 %). The overall complication rate was 2.3 %. Risk factors for bleeding in multivariate analysis were only patients under 60 years of age. Risk factors for perforation in multivariate analysis were en bloc resection and Vienna classification category 4–5. The difference of complication rate was not statistically significant regarding gender, size, tumor location, gross appearance, treatment method, and kind of insufflation. Conclusion: CER is a safe, efficient, and effective minimally invasive therapy for large colorectal lesions. However, care should be taken for post procedure bleeding in patients under 60 years of age and for perforation in cases of Vienna classification category 4–5 or when an en bloc resection is tried.