Objective:This study aims to explore the independent risk factors for portal vein thrombosis（PVT）formation after splenectomy and selective shunt surgery，to construct a nomogram model predicting postoperative PVT，and to clarify the clinical efficacy of inte grative medicine interventions in preventing postoperative PVT.Methods:A retrospective analysis was conducted on clinical data of inpatients undergoing splenectomy or selective shunt surgery for liver cirrhosis at the affiliated hospital of Shaanxi University of Chinese Medicine from August 2014 to December 2022.The study was divided into two parts:Patients were grouped into PVT and non-PVT groups based on the presence of postoperative PVT.Univariate analysis，LASSO regression，and binary logistic regression were performed on general patient characteristics，preoperative and postoperative indicators.A nomogram prediction model was then constructed，with model evaluation using ROC and calibration curves.For patients who received Western medical intervention，they were further divided into a control group and a treatment group based on whether they took traditional Chinese medicine promoting blood circulation and removing blood stasis.The effects of intervention timing and methods on postoperative PVT formation were analyzed，along with comparisons of blood routine and coagulation indices between the two groups.Additionally，the composition of specific traditional Chinese medicines used in the integrated intervention group was statistically analyzed.Results:Analysis of independent risk factors for postoperative PVT formation and the establishment of a nomogram model:This part of the study ultimately included 227 patients，of which 112 developed PVT postoperatively，and 115 did not. Compared with the non-PVT group，patients in the PVT group had differences in age，portal vein diameter（PVD），white blood cell count（WBC）on postoperative day 1，platelet count（PLT），PLT increase，and PLT and PLT increase on postoperative days 3 and 7，all of which were statistically significant（P＜0.05）.According to LASSO-Logistic regression analysis，PVD and PLT increase on postoperative day 7 were independent risk factors for postoperative PVT formation.When PVD ≥ 15.1 mm and PLT increase on postoperative day 7 ≥278.5 ×10⁹ L^-1，the incidence of PVT significantly increased. Based on the Logistic regression analysis，a nomogram prediction model was constructed with an AUC value of 0.756，95% CI（0.693-0.820），and the calibration curve showed good fit，indicating good predictive performance.Evaluation of postoperative PVT formation with integrated Chinese and Western medicine intervention:This part of the study included 127 patients，of whom 60 developed PVT postoperatively，and 67 did not. Compared with the non-PVT group，patients in the PVT group-initiated intervention later，with statistically significant differences（P＜0.05）. Compared with the Western medicine intervention group，the integrated Chinese and Western medicine intervention group had a lower postoperative PVT incidence，with statistically significant differences（P＜0.05）.After treatment，the integrated group also had lower levels ofWBC，PLT，D-dimer（D-D），and fibrin degradation products（FDP），with statistically significant differences（P＜0.05）. Conclusion:PVD and PLT increase on postoperative day 7 are independent risk factors for postoperative PVT formation.When PVD ≥15.1 mm and PLT increase on postoperative day 7 ≥278.5 ×10⁹ L^-1，the incidence of PVT significantly increases.Integrated Chinese and Western medicine intervention can inhibit postoperative PLT elevation，reduce WBC，D-D，and FDP levels，and decrease the occurrence of PVT.