DOPPLER ENDOSCOPIC PROBE BLOOD FLOW MONITORING AND FOCAL TREATMENT PREVENT DELAYED POST-POLYPECTOMY INDUCED ULCER HEMORRHAGE IN A RANDOMIZED CONTROLLED TRIAL

INTRODUCTION: Hemoclip (HC) closure has mixed success rates for prevention of delayed post-polypectomy induced ulcer hemorrhage (DPPIUH). This is because HC is a single layer closure which buries submucosal arteries, often without obliterating blood flow. It also is reported not to be cost effective nor effective in the left colon. Doppler endoscopic probe (DEP) monitoring & focal obliteration of arterial blood flow in peptic ulcer bleeding is very effective & this technique has been applied after colon polypectomy to risk stratify & focally treat arteries in PPIU’s to prevent DPPIUH.

PURPOSE: To report results of a randomized controlled trial (RCT) of blood flow monitoring to prevent DPPIUH.

METHODS: This is a multicenter RCT of high-risk 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 ASGE 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. abdominal pain, vomiting, fever 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 for 5 or more days &/or for severe bleeding but refusal of hospitalization during the COVID pandemic. Lesser bleeds were < 4 days, but without hospitalization. Demographic, laboratory, colonoscopic, & pathology results & 30 day outcomes were prospectively recorded on standard forms. Coded data were entered onto HIPAA compliant computer files & managed with SAS. This was a planned analysis by a biostatistician when the calculated sample size was reached.

RESULTS: For 174 high risk patients, 87 had standard treatment & 87 had DEP guided treatment. DEP monitoring and focal treatment was quick and easy. Treatment groups were well matched at baseline (See Table 1). However, DEP patients had significantly lower rates of DPPIU bleeding – both major & total (Table 2). There were no severe adverse events.

CONCLUSIONS: 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 strategic method to prevent DPPIUH throughout the colon than empiric HC closure of PPIU’s.