Objective:To investigate the risk factor analysis and model prediction of bleeding after endoscopic retrograde cholangiopancreatography in patients with malignant obstructive jaundice (MOJ).Methods:A retrospective analysis was performed on 302 patients with MOJ treated with ERCP who were treated in the No. 363 Hospital Affiliated to Southwest Medical University from January 2015 to June 2021. The general clinical data of the patients were collected, and the biochemical indicators of the pancreatic and bile ducts were detected. The patients were followed up after discharge, and the patients were divided into a bleeding group ( n=47) and a control group ( n=255) according to whether the follow-up patients were bleeding after ERCP. Compared the general and clinical data of the two groups of patients, including age, gender, platelet count, presence of bile duct stones, acute cholangitis, acute pancreatitis, number of stones, intraoperative bleeding, pancreatic cancer, cholangiocarcinoma, large stone diameter, stone incarceration, duodenal papillary diverticulum, and pre-surgical incision. The measurement data that obey the normal distribution were represented by the mean±standard deviation ( ± s), and the two independent sample t test was used for the comparison between groups; the data that do not conform to the normal distribution were represented by M ( Q1, Q3), and the comparison between groups was used Mann-Whitney U test. The comparison of enumeration data between groups adopted chi-square test. Logistic multivariate regression was used to analyze the independent risk factors of postoperative bleeding after ERCP, and a nomogram prediction model was established and verified according to the independent risk factors of postoperative bleeding. Results:The two groups of patients were compared in age, gender, platelet count, bile duct stones, acute cholangitis, acute pancreatitis, the number of stones, intraoperative bleeding and other aspects, the difference was not statistically significant ( P>0.05). The percentages of pancreatic cancer, cholangiocarcinoma, large stone diameter, stone incarceration, duodenal papillary diverticulum, and surgical pre-incision in the bleeding group were 12.77%, 17.02%, 19.15%, 51.06%, 59.57%, and 14.89%, respectively. , the percentages of the control group were 3.92%, 5.10%, 9.02%, 19.22%, 17.65%, and 5.88%, and the difference was statistically significant between the two groups ( P<0.05). Taking postoperative bleeding as the dependent variable, and using the indicators with statistical differences in univariate analysis as independent variables, multivariate Logistic regression analysis showed that the patient had pancreatic cancer ( OR=1.838, 95% CI: 1.524-4.613, P=0.041), cholangiocarcinoma ( OR=2.548, 95% CI: 1.870-5.116, P=0.015), stone incarceration ( OR=3.078, 95% CI: 2.374-6.012, P<0.001), duodenum Intestinal papillary diverticula ( OR=1.140, 95% CI: 1.045-1.628, P<0.001), surgical pre-incision ( OR=1.640, 95% CI: 1.321-1.928, P<0.001) were associated with postoperative bleeding in MOJ patients after ERCP independent risk factors. The predictive ability of duodenal papillary diverticulum was the highest; the predictive ability of stone incarceration and cholangiocarcinoma was the second, and there was no significant difference between them; the predictive ability of pancreatic cancer, stone diameter, and pre-incision on bleeding after ERCP in MOJ patients smaller. Pancreatic cancer, cholangiocarcinoma, large stone diameter, stone incarceration, duodenal papillary diverticulum, and pre-incision scores were 42, 63, 28, 65, 76, and 34 points respectively, and the total score was 308 points corresponding to the nomogram model. The predictive power of the nomogram was 61.6%, and overall, the nomogram had good predictive performance. Harrell concordance index analysis and ROC curve were used to evaluate the model discrimination, the C-index calculation result was 0.826 (95% CI: 0.771-0.847), the ROC curve AUC was 0.843 (95% CI: 0.801-0.884), and the ROC prediction The value and the calculation result of C-index are relatively close. The model discrimination is applied in this study and has a certain prediction effect. The nomogram model in the Calibration curve predicted the probability of postoperative bleeding after ERCP in MOJ patients with high consistency with the actual probability. Conclusion:ERCP is safe and feasible for most patients with MOJ, but for patients with pancreatic cancer, bile duct cancer, large stone diameter, stone incarceration, and duodenal papillary diverticulum, it should be performed with caution, and preoperative incision should be avoided, to reduce the risk of postoperative bleeding. In addition, the nomogram model has a strong predictive ability in predicting bleeding after ERCP in patients with MOJ, which is worthy of reference in clinical research.

Objective To evaluate the rupture risk of carotid atherosclerotic plaque under cervical rotatory manipulation. Methods The fluid-structure interaction (FSI) model of carotid atherosclerotic plaque was established, and tensile deformation of the plaque and lumen under cervical rotatory manipulation was simulated.Mechanical parameters such as the maximum flow shear stress(FSS), the maximum wall shear stress (WSS), the maximum plaque wall stress (PWS), wall tensile stress (WTS) and wall pressure (WP) of the plaque and lumen were recorded. Results Under 16% carotid tensile deformation, the maximum WSS of the plaque was 40.54 Pa. The maximum PWS was 66.16 kPa, which was far smaller than the threshold of plaque rupture.The maximum WTS of fiber cap and the maximum strain were 156.75 kPa and 0.56, which were larger than the fracture strain range. The maximum WTS of the lumen was 1 040.30 kPa, which approached the threshold of medial membrane rupture and might cause vascular injury. Conclusions When the cervical spine rotates to the end range of motion, large carotid artery stretch may cause damage to epidermal tissues of the plaque, leading to abscission. Lesions, ulcers, bleeding and vascular damage may form inside the plaque, which will affect stability of the plaque. Cervical rotatory manipulation should be performed cautiously in patients with cervical diseases who also have carotid atherosclerotic plaques.The finite element assessment of plaques before manipulation may be an effective safety screening method.