Treatment with argon plasma coagulation reduces recurrence after piecemeal resection of large sessile colonic polyps: a randomized trial and recommendations Jim C. Brooker, MRCP, Brian P. Saunders, MD, Syed G. Shah, MRCP, Catherine J.Thapar, RGN, Noriko Suzuki, MD, Christopher B. Williams, FRCP, FRCS London, United Kingdom Background: Recurrence is frequent after piecemeal snare resection of large sessile colorectal polyps.The aim of this study was to evaluate the safety and efficacy of argon plasma coagulation (APC) in preventing recurrence when applied to the edge and base of the polypectomy site after apparently complete piecemeal resection. Methods: Patients with large (>1.5 cm) sessile polyps removed by piecemeal snare cautery were placed into 2 groups.The first consisted of patients with polyps believed by the endoscopist to be completely excised. These patients were randomized to either no further therapy (control) or to APC of the rim and any residual mucosal or submucosal tissue in the base of the polypectomy site. The second group comprised patients in whom polyps, as judged by the endoscopist, were incompletely excised by snare polypectomy; APC was routinely applied without randomization to all visible remaining adenomatous tissue. Follow-up colonoscopy was performed within 3 months and 1 year; biopsy specimens were taken routinely from the resection site and further polypecto- my was performed as indicated. Results: There were fewer recurrences after APC in the randomized group (1/10 APC, 7/11 no APC; p = 0.02). In the group with initial incomplete snare polypectomy, recurrence was detected at 3 months in 6 of 13 despite APC. One patient was hospitalized with abdominal pain and minor rec- tal bleeding but required no intervention. There were no other episodes of significant late bleed- ing caused by piecemeal polypectomy. One patient was referred for surgery after unsuccessful endoscopic management. Conclusions: In patients with apparent complete endoscopic snare resection of large adenomas, postpolypectomy application of APC reduces adenomatous recurrence. (Gastrointest Endosc 2002;55:371-5.) VOLUME 55, NO. 3, 2002 GASTROINTESTINAL ENDOSCOPY 371 Large sessile colonic polyps are an important clin- ical problem because of their propensity for malig- nant transformation. 1 Endoscopic snare resection became feasible with the advent of piecemeal 2 and submucosal injection 3,4 techniques. However, recur- rence is common 5-7 and delay in adequate treatment risks malignant change. The presence of residual viable adenoma tissue, the cause of subsequent recurrence, may not be appreciated after apparently complete endoscopic resection. Thermal ablation methods have therefore been used in an attempt to eradicate both visible and microscopic residual ade- nomatous tissue after snare resection. Monopolar devices such as the “hot biopsy” forceps are not suit- ed to the treatment of large mucosal areas, and the depth of tissue injury may be excessive. 8 Lasers are expensive and their use may result in full-thickness colonic injury and perforation. 9,10 However, argon plasma coagulation (APC) is a noncontact method of delivering electrosurgical energy that is suitable for treating large mucosal areas, with coagulation occur- ring to a limited and predictable depth. 11 Results from a noncontrolled study suggested that APC should be a useful adjunct to the endoscopic man- agement of large sessile polyps. 12 These are the results of the first randomized controlled trial of APC therapy for this indication. It was hypothesized that APC after piecemeal resection would reduce 3- month recurrence of large sessile colonic adenomas. PATIENTS AND METHODS Consecutive patients undergoing colonoscopy with known large benign sessile colonic polyps suitable for endo- scopic resection were prospectively enrolled. The study pro- tocol was approved by the ethics committee of our institu- Received February 19, 2001. For revision May 11, 2001. Accepted July 20, 2001. From the Wolfson Unit for Endoscopy, St. Mark’s Hospital, London, United Kingdom. Funded by the Henry Smith Foundation. Reprint requests: Brian P. Saunders, MD, Wolfson Unit for Endoscopy, St. Mark’s Hospital, Northwick Park, London, HA1 3UJ, United Kingdom. Copyright © 2002 by the American Society for Gastrointestinal Endoscopy 0016-5107/2002/$35.00 + 0 37/1/121597 doi:10.1067/mge.2002.121597