Objective  To investigate the independent risk factors for venous thromboembolism (VTE) after gynecological surgery, evaluate the predictive performance of postoperative D-dimer levels for VTE, and inform the development of individualized anticoagulation strategies.

Methods  Perioperative data were collected from 307 female patients who underwent gynecological surgeries at West China Shangjin Nanfu Hospital, Sichuan University between March 2020 and March 2022. The inclusion criteria were a Caprini score ≥ 3 and the absence of any VTE prophylaxis. The data collected included age, body mass index (BMI), menopause, comorbidities (e.g., hypertension), preoperative and postoperative coagulation parameters (prothrombin time, activated partial thromboplastin time, fibrinogen, D-dimer, etc.), the surgical approach, anesthesia duration, surgery duration, American Society of Anesthesiologists (ASA) physical status classification, and postoperative VTE occurrence confirmed by imaging examinations. Patients were divided into VTE and non-VTE groups according to postoperative imaging findings. Univariate analysis was performed to compare differences between groups. Binary logistic regression was performed to identify independent risk factors. The receiver operating characteristic (ROC) curve was plotted, and the area under the curve (AUC), sensitivity, specificity, and Youden index were calculated to evaluate the predictive performance of D-dimer levels.

Results  Among the 307 patients, 42 (13.68%) developed postoperative VTE, including 30 cases (9.77%) of deep vein thrombosis (DVT) and 12 cases (3.91%) of pulmonary embolism (PE). Multivariable logistic regression analysis showed that independent risk factors for postoperative VTE included age (odds ratio OR = 1.122 per year, 95% CI: 1.070-1.176), increased BMI (OR = 1.180, 95% CI: 1.031-1.351), menopause (OR = 13.753, 95% CI: 3.692-51.229), hypertension (OR = 3.951, 95% CI: 1.837-8.498), prolonged surgery duration (OR = 1.047 per minute, 95% CI: 1.013-1.082), prolonged anesthesia duration (OR = 1.007 per minute, 95% CI: 1.002-1.011), higher ASA classification (OR = 8.122, 95% CI: 2.973-22.184), and elevated postoperative D-dimer levels (OR = 1.177 per mg/L, 95% CI: 1.029-1.346). Although the Caprini score was significantly higher in the VTE group than that in the non-VTE group (4.57 ± 1.21 vs. 3.64 ± 1.11, P < 0.001), binary logistic regression analysis revealed no statistically significant association (P = 0.877). A postoperative D-dimer level = 1.50 mg/L was the optimal threshold for diagnosing VTE, yielding a sensitivity of 54.76%, specificity of 73.58%. A preoperative-to-postoperative D-dimer change = 2.50 mg/L showed a sensitivity of 26.19%, specificity of 94.72%.

Conclusion Increased age, higher BMI, menopause, hypertension, prolonged surgery duration and anesthesia duration, and higher ASA classification are independent risk factors for VTE after gynecological surgery. A postoperative D-dimer level ≥ 1.50 mg/L and a preoperative-to-postoperative D-dimer change ≥ 2.50 mg/L may serve as practical indicators for VTE screening and early risk identification and should be incorporated into routine postoperative monitoring. The Caprini score demonstrated limited predictive value for VTE risk in this gynecological patient cohort. Therefore, a risk assessment model tailored to patients undergoing gynecological surgery should be developed by incorporating these risk factors.