Factors associated with delayed bleeding after resection of large nonpedunculated colorectal polyps.

BACKGROUND:  Delayed bleeding is the most common significant complication after piecemeal endoscopic mucosal resection (p-EMR) of large nonpedunculated colorectal polyps (NPCPs). Risk factors for delayed bleeding are incompletely defined. We aimed to determine risk factors for delayed bleeding following p-EMR.

METHODS:  Data were analyzed from a prospective tertiary center audit of patients with NPCPs ≥ 20 mm who underwent p-EMR between 2010 and 2012. Patient, polyp, and procedure-related data were collected. Four post p-EMR defect factors were evaluated for interobserver agreement and included in analysis. Delayed bleeding severity was reported in accordance with guidelines. Predictors of bleeding were identified.

RESULTS:  Delayed bleeding requiring hospitalization occurred after 22 of 330 procedures (6.7 %). A total of 11 patients required blood transfusion; of these, 4 underwent urgent colonoscopy, 1 underwent radiological embolization, and 1 required surgery. Interobserver agreement for identification of the four post p-EMR defect factors was moderate (kappa range 0.52 - 0.57). Factors associated with delayed bleeding were visible muscle fibers ( P  = 0.03) and the presence of a "cherry red spot" ( P  = 0.05) in the post p-EMR defect. Factors not associated with delayed bleeding were American Association of Anesthesiologists class, aspirin use, polyp size, site, and use of argon plasma coagulation.

CONCLUSIONS:  Visible muscle fibers and the presence of a "cherry red spot" in the resection defect were associated with delayed bleeding after p-EMR. These findings suggest evaluation and photodocumentation of the post p-EMR defect is important and, when considered alongside other patient and procedural factors, may help to reduce the incidence and severity of delayed bleeding.