Abstract:

Objective To analyze the risk factors of hemorrhage after endoscopic mucosal resection (EMR) for adenomatous polyps of the large intestine, and to construct a nomogram model of postoperative hemorrhage for adenomatous polyps of the large intestine. Method A total of 300 patients with colorectal adenomatous polyps treated with EMR from January to December 2023 were selected as the modeling group, and 150 patients with colorectal adenomatous polyps treated with EMR from January to June 2024 were selected as the verification group. The patients in the modeling group were divided into bleeding group and non-bleeding group according to whether they experienced postoperative bleeding. Logistic regression analysis was used to screen the risk factors of postoperative bleeding for adenomatous polyps of the large intestine, and R language was used to establish a nomogram model for predicting postoperative bleeding for adenomatous polyps of the large intestine, and finally the model fit and prediction efficiency were evaluated. Result Among the 300 patients, 31 patients had hemorrhage, the incidence of hemorrhage was 10.33%. Clinical data such as smoking history, drinking history, comorbidities, educational level, place of residence, marital status, body mass index, polyp site, number of removed polyps, whether there were tilts and whether there were smooth polyps were compared between the bleeding group and the non-bleeding group , have no significant difference(P ＞ 0.05), while clinical data such as age, sex, polyp size, and whether there were lobed polyps were compared, have a significant difference(P ＜ 0.05). Logistic regression analysis showed that age, sex, polyp size and lobulation were all risk factors for hemorrhage after EMR operation(P ＜ 0.05). The model consistency index (C-index) was 0.851 (95%CI: 0.818-0.884). H-L test showed that the model fit well (χ2=5.365, P=0.305). Receiver operator characteristic curve results showed that the area under the curve value of the nomogram model of hemorrhage after EMR was 0.825. The predicted value of correction curve is close to the actual value. When the prediction threshold probability ranged from 6% to 87%, the net benefit value of nomogram in predicting bleeding after EMR for colorectal adenomatous polyps was higher. Conclusion The nomogram of bleeding risk after endoscopic mucosal resection of adenomatous polyps in the large intestine established in this study is conducive to early clinical identification of high-risk groups for postoperative bleeding, and the nomogram risk prediction model established in this study has guiding significance for medical personnel to make postoperative bleeding prevention and treatment plans.

Key words: Colorectal adenomatous polyp, Endoscopic mucosal resection, Bleeding, Nomograph