Mo1408 Advanced Polyps and Adjuvant APC- Time for a Rethink?

Abstract

Advanced Polyps and Adjuvant APCTime for a Rethink? Patrick Wilson*, Olga Niewiadomski, David Devonshire, Michael Swan, Malcolm B. Barnes MMC Melbourne, Melbourne, VIC, Australia Introduction: Large colonic polyps follow a well-defined pathway of progression to carcinoma. Endoscopic mucosal resection (EMR) has been widely adopted and is minimally invasive and cost effective compared to surgery. However, recurrence following EMR of large colorectal lesions occurs in between 10-50% of cases at follow up within 12 months; this is likely due to remnant or residual tissue. Argon plasma coagulation (APC) is an ablative technique that may reduce recurrence rates following EMR, to 10-14%, (1). Aim: To assess the efficacy and safety of adjuvant APC to reduce the recurrence rate of large colorectal lesions ( 15mm) undergoing endoscopic resection. Methods: Data was prospectively collected over an 8 year period (from Jan 2003 to November 2011) on patients with large laterally spreading colorectal polyps ( 15mm) undergoing EMR. The procedure was done by 3 endoscopists using saline/adrenaline/indigo carmine submucosal injection followed by endoscopic mucosal resection. APC (40 watts proximal colon and 20 watts distal colon) was applied to the edge of the mucosal defect in all cases of complete endoscopic resection and to the edges and residual tissue in cases of incomplete resection. Endoscopic follow-up was performed by 12 months to assess for local recurrence, with biopsies taken if there was suspicion of recurrence. Results: A total of 178 patients, mean age of 72, had 188 polyps. 88% had complete initial resection, 12% were incomplete resections. Operative management was required in 8 cases (4.6% of cases) following the initial colonoscopy (7 due to advanced pathology and 1 due to perforation). Adenocarcinoma was found in 14 polyps, half were treated successfully endoscopically. Follow up data is currently available in 72 patients (78 polyps), a mean of 9 months later. The overall recurrence rate was 17%, for complete initial resection the recurrence rate was 9%, %, for incomplete resection the rate was 38%. Conclusion: Although the use of APC in this setting is not a new concept, there remains a question over its safety and effectiveness, and it is not yet standard of care in many institutions. The data we present show that in this institution adjuvant APC is safe (perforation and bleeding rates were similar to rates for polypectomy alone (2). The recurrence rate of polyps that have been fully excised at initial polpectomy is lower than rates often quoted (2). Even in polyps not expected to be cleared due to unfavorable morphology and histology, resection was complete in over 60%