Risk Factors for Deep Vein Thrombosis After Surgery in Patients with Gastric or Colorectal Cancer Receiving Anticoagulant Prophylaxis.

Abstract

Our objective was to identify perioperative predictors of early postoperative lower-extremity deep vein thrombosis (DVT) in patients undergoing surgery for gastric or colorectal cancer who received routine pharmacologic thromboprophylaxis and to develop a nomogram for postoperative risk stratification. This retrospective study included patients with gastric or colorectal cancer undergoing surgery from December 2020 to October 2023. All received postoperative low-molecular-weight heparin prophylaxis, and DVT was screened by ultrasonography on postoperative day 3. Predictors were identified by logistic regression and incorporated into a nomogram. A total of 388 eligible patients were included, among whom 124 (32.0%) had screening-detected postoperative lower-extremity DVT. Among patients with DVT, 118 (95.2%) had distal-only DVT and 114 (91.9%) were asymptomatic. Multivariable logistic regression identified age, activated partial thromboplastin time, prothrombin time, and postoperative day 1 D-dimer as independent predictors of postoperative DVT. The nomogram showed acceptable discrimination, with area under the receiver operating characteristic curve values of 0.787 (95% confidence interval 0.731-0.844) in the training cohort and 0.854 (95% confidence interval 0.774-0.934) in the validation cohort. Calibration curves showed good agreement between predicted and observed risks. In decision curve analysis, the nomogram provided greater net benefit for risk classification than strategies classifying all or no patients as high risk. Age, activated partial thromboplastin time, prothrombin time, and postoperative day 1 D-dimer were independently associated with screening-detected early postoperative DVT. The resulting nomogram may help postoperative risk stratification and closer surveillance; however, external validation is required before routine clinical application.