Doppler Endoscopic Probe Blood Flow Monitoring and Focal Treatment Prevents Delayed Post-Polypectomy-Induced Ulcer Hemorrhage in a Randomized Controlled Trial

Introduction: Hemoclip (HC) closure has mixed success for prevention of DPPIUH probably because it is a single layer closure which buries submucosal arteries without obliterating blood flow. It also is reported not to be cost effective. DEP monitoring & focal obliteration of arterial blood flow in peptic ulcer bleeding is very effective & this technique has been applied after polypectomy to risk stratify & prevent DPPIUH. Our AIM is to report results of an RCT of blood flow monitoring to prevent DPPIUH. Methods: This is a multicenter RCT of outpatients having colonoscopies & prospective follow-up (FU). Polyps were removed by EMR &/or thermal coagulation. Patients were stratified by whether they took chronic anti-platelet or anti-thrombotic drugs & had a PPIU of 10-40 mm; or for those without bleed drugs, PPIU’s were 15-40 mm. After polypectomy, randomization was to either standard management (e.g. following ACG guidelines for bleed drugs) or DEP interrogation of PPIU’s & guided treatment with hemoclips or multipolar probe coagulation in the PPIU until arterial blood flow was eradicated. Patients & their care-givers were blinded to treatment allocations. Prospective FU was by a research coordinator at 7, 14, & 30 days to record all complications (e.g. pain, vomiting, or dizziness); rectal bleeding & its severity (e.g. # bloody BM’s/day & # of days bleeding); or whether patients sought ER, clinic, or telemedicine care for bleeding or were hospitalized. Major DPPIUH was diagnosed in patients hospitalized for severe bleeding &/or for 5 or more days of severe bleeding but refused hospitalization. Lesser bleeds were < 4 days. Demographic, laboratory, colonoscopic, & pathology results; & 30 day outcomes were recorded on standard forms. Coded data were entered onto HIPAA compliant computer files & managed with SAS. This was a planned analysis by a statistician when the calculated sample size was reached. Results: See Table 1. For 170 high risk patients, 86 were standard treatment & 84 were DEP. Groups were clinically well matched. However, DEP patients had significantly lower rates of DPPIU bleeding – both major & total. There were no severe adverse events. Conclusion: DEP monitoring of arterial blood flow & guided treatment resulted in significantly lower rates of DPPIUH than standard treatment; was easy & safe; & is a more anatomically feasible method to prevent DPPIUH throughout the colon than empiric HC clOhio State Universityre of PPIU’s. Table 1. - Background Variables and Delayed Post Polypectomy Induced Ulcer Bleeds by Treatment Group Background Variables Standard (N=86) Doppler (N=84) P-Value Age* 67.7 ± 8.2 68.5±8.0 0.07 Gender Male 69 (80.2%) 75 (89.3%) Female 17 (19.8%) 9 (10.7%) 0.10 Charlson Comorbidity* 5.48 ± 2.54 5.02 ± 2.38 0.12 ASA Class* 2.22 ± 0.44 2.17 ± 0.53 0.68 Aspirin + 48 (58.9%) 48 (57.1%) 0.86 Other Anti-Platelet Drug + 11 (12.8%) 5 (6.0%) 0.13 Anti-Coagulant + 19 (22.1%) 18 (21.4%) 0.92 Polyp Location Right Colon** 50 (58.1%) 50 (59.5%) Left Colon*** 36 (41.9%) 34 (40.5%) 0.85 Polyp Size* (mm) 16.4 ± 8.1 15.1 ± 6.2 < 0.05 PPIU Size* (mm) 17.0 ± 7.6 15.8 ± 6.1 < 0.05 Delayed Bleeds Total Delayed PPIU Bleeds 10 (11.63%) 2 (2.38%) 0.0186 Major Delayed Bleeds 7 (8.14%) 1 (1.19%) 0.0324 Lesser Delayed Bleeds 3 (3.49%) 1 (1.19%) 0.3230 *Expressed as mean ± standard deviation. + Chronic medication for a co-morbidity - resumed the day after colonoscopy. PPIU is post-polypectomy induced ulcer size (in mm).** Right colon includes transverse and ascending colon and cecum. *** Left colon includes splenic flexure, descending colon, sigmoid colon and rectum. Abbreviations: ASA = American Society of Anesthesiologists, PPIU = Post Polyp Induced Ulcer.