A Scoring System to Determine Risk of Delayed Bleeding After Endoscopic Mucosal Resection of Large Colorectal Lesions

Background & aims: After endoscopic mucosal resection (EMR) of colorectal lesions, delayed bleeding is the most common serious complication, but there are no guidelines for its prevention. We aimed to identify risk factors associated with delayed bleeding that required medical attention after discharge until day 15 and develop a scoring system to identify patients at risk.

Methods: We performed a prospective study of 1214 consecutive patients with nonpedunculated colorectal lesions 20 mm or larger treated by EMR (n = 1255) at 23 hospitals in Spain, from February 2013 through February 2015. Patients were examined 15 days after the procedure, and medical data were collected. We used the data to create a delayed bleeding scoring system, and assigned a weight to each risk factor based on the β parameter from multivariate logistic regression analysis. Patients were classified as being at low, average, or high risk for delayed bleeding.

Results: Delayed bleeding occurred in 46 cases (3.7%, 95% confidence interval, 2.7%-4.9%). In multivariate analysis, factors associated with delayed bleeding included age ≥75 years (odds ratio [OR], 2.36; P < .01), American Society of Anesthesiologist classification scores of III or IV (OR, 1.90; P ≤ .05), aspirin use during EMR (OR, 3.16; P < .05), right-sided lesions (OR, 4.86; P < .01), lesion size ≥40 mm (OR, 1.91; P ≤ .05), and a mucosal gap not closed by hemoclips (OR, 3.63; P ≤ .01). We developed a risk scoring system based on these 6 variables that assigned patients to the low-risk (score, 0-3), average-risk (score, 4-7), or high-risk (score, 8-10) categories with a receiver operating characteristic curve of 0.77 (95% confidence interval, 0.70-0.83). In these groups, the probabilities of delayed bleeding were 0.6%, 5.5%, and 40%, respectively.

Conclusions: The risk of delayed bleeding after EMR of large colorectal lesions is 3.7%. We developed a risk scoring system based on 6 factors that determined the risk for delayed bleeding (receiver operating characteristic curve, 0.77). The factors most strongly associated with delayed bleeding were right-sided lesions, aspirin use, and mucosal defects not closed by hemoclips. Patients considered to be high risk (score, 8-10) had a 40% probability of delayed bleeding.