Endoscopic snare resection of large colonic polyps: how far can we go?

Colonoscopic polypectomy is preventing colorectal cancer. Videoendoscopy and new perendoscopic hemostasis techniques make endoscopic polypectomy of large colonic polyps an alternative to the surgical approach. This study examined whether complete snare resection of giant colonic polyps is feasible and safe and for determining how often surgery is necessary due to invasive cancer detected histologically after polypectomy.

The study included 59 consecutive patients with 68 colonic polyps larger 30 mm in diameter. Snare polypectomy was performed after an endoscopic ultrasound with a miniprobe found no sign of invasive, or, depending on the appearance of the polyp, a bleeding prophylaxis had been carried out. Acute procedural or delayed bleeding was treated endoscopically.

Of the 68 polyps 26, mostly pedunculated were resected en bloc (38%) and histologically ensured as completely resected; 42 polyps had to be resected by piecemeal technique (62%). Piecemeal resection was performed significantly more often in sessile polyps (38/41, 93%) than in pedunculated polyps (4/27, 15%, P<0.01). Follow-up colonoscopy after 3 months showed remaining adenomatous tissue of piecemeal-resected polyps in 12 cases (28%), which were 12 resected sessile polyps (29%) and no case of resected pedunculated polyp. To achieve complete resection of sessile polyps a second procedure was necessary significantly more often than for resection of pedunculated polyps (12 cases in sessile polyps, 18% vs. no case in pedunculated polyps). Remaining adenomatous tissue was removed in all 12 cases during the first follow-up colonoscopy after 3 months, confirmed by a biopsy 6 months after the initial procedure. Overall coexisting malignancy was found in only 7 polyps (12%). Due to high-risk factors only one of them underwent secondary surgical procedure.

The present study shows that endoscopic snare resection of giant colonic polyps is a safe procedure, and that secondary operative measures for managing coexisting malignancy are rarely necessary.