Endoscopic Resection of 107 Large Sessile Polyps: Outcome and Predictors of Cure

Abstract

Background: Large sessile colorectal adenomas (LSAs) (≥2 cm in size) resected piecemeal have a 14-55% rate of residual adenoma at first follow-up. Guidelines recommend inspection of the polypectomy site 3-6 months after resection. Some patients with a negative exam at 3-6 months have a subsequent “late” recurrence. Few studies have reported long term follow-up in these patients. Methods: LSAs were identified by review of an endoscopic database. Polyps were resected by piecemeal snare technique; flat areas that could not be snared were treated with argon plasma coagulation. Only patients who completed a first follow-up exam at 3-6 months and a second follow-up exam ≥1 year after initial resection were included. Endoscopic and pathologic data at both follow-ups were reviewed. Groups of patients with and without adenoma recurrence/persistence were compared. Results: During the study period, 105 patients (52 Female) with 107 LSAs (mean size 33.2 mm) were included. The recurrence/persistence rate at first follow-up was 20.1%; 22 patients (Group A) had persistent or recurrent adenomas, of which 15 had visible polyps and 7 had no visible polyps but biopsy of the polypectomy scar showed adenomatous tissue. Of the 85 polyps (Group B) with no evidence of recurrence at first follow-up, 70 had no visible adenoma and a normal scar biopsy and 15 had no visible adenoma but did not undergo scar biopsy. A total of 6 patients (5.8%) had polyp recurrence/persistence at 1 year, including 4 patients (18.2 %) from group A and 2 patients (2.4%) from group B (p = 0.004). Of the 70 patients from group B who had a normal scar biopsy at first follow-up, only 1 patient had an adenoma at 1 year (1.4%). All 6 recurrent/persistent polyps at 1 year were snare resected and there was no evidence of any further recurrence/persistence after an additional 6 to 12 months of follow-up. The mean size at baseline of the polyps that recurred/persisted at first follow-up was significantly larger than that of the polyps that did not (41.8 mm vs. 31 mm, p = 0.003). Conclusion: Endoscopic piecemeal resection and ablation of LSAs is effective though some patients require >2 sessions to achieve and ensure complete eradication. The lowest recurrence/persistence rates were among patients with smaller polyps and those who had no visible adenoma and a negative polypectomy scar biopsy at 3-6 months. Absence of visible adenoma and a negative scar biopsy at 3-6 months follow-up are predictive of long term cure.