Colorectal Post-polypectomy Bleeding in Outpatient versus Inpatient Treatment: Propensity Score Matching Analysis

Delayed bleeding is the most frequent adverse event associated with endoscopic mucosal resection (EMR) and hot snare polypectomy (HSP) of colorectal polyps. However, whether the incidence of delayed bleeding differs between outpatient and inpatient treatment is unknown. Therefore, in this study, we aimed to evaluate delayed bleeding rates between outpatient and inpatient endoscopic treatments and clarify the safety of outpatient treatment.

We enrolled 469 patients (1077 polyps) and 420 patients (1080 polyps) in the outpatient and inpatient groups, respectively, who underwent EMR or HSP for colorectal polyps at our institution between April 2020 and May 2023. Using propensity score matching, we evaluated the delayed bleeding rates between the two groups. Delayed bleeding was defined as a hemorrhage requiring endoscopic hemostasis occurring within 14 days of the procedure.

Propensity score matching created 376 (954 polyps) matched patient pairs. The median maximum diameter of polyps removed was 10 mm in both groups. Delayed bleeding rates per patients were 1.3% (5/376) in the outpatient group and 2.9% (11/376) in the inpatient group (P=0.21). In term of per polyp, early delayed bleeding (occurring within 24 hours) rates were higher in the inpatient group than outpatient group (0.2% [2/954] vs. 1.1% [10/954], respectively; P=0.04). No severe bleeding requiring a transfusion occurred in either group.

Outpatient endoscopic treatment did not increase delayed bleeding compared with inpatient treatment. Outpatient treatment would be safe and common for the removal of colorectal polyps.