To explore the value of Caprini risk assessment scale and serum D-dimer in early prediction of postoperative lower extremities deep vein thrombosis (DVT) in patients with gastrointestinal malignant tumor.

A total of 240 patients with gastrointestinal malignant tumors treated in Union Hospital of Tongji Medical College of Huazhong University of Science and Technology from Jan to Oct 2020 were analyzed retrospectively.

Caprini score was 4 in 8 cases, 5-7 in 217 cases, and 8 in 15 cases. Sixty-seven patients developed lower extremity DVT after operation. No patients with Caprini score of 4 had DVT, 57 cases (26.3%) with a score of 5-7 had DVT; 10 cases whose score were ≥8 points (66.7%) developed DVT. There was a higher incidence of lower extremity DVT in patients ≥8 points than those of 5-7 points after surgery (P<0.01). The postoperative Caprini score of the DVT group was higher than that of the non-DVT group (6.37±1.01 vs. 5.80±0.94, t=4.108, P<0.001). D-dimer on the first day after operation in DVT group (4.08±2.27 vs. 2.01±1.04, t=7.715, P<0.001) and the level of serum D-dimer (2.93±1.81 vs. 2.30±1.21, t=2.631, P<0.001) on day 3 was higher than that in the non-DVT group. According to the ROC curve, the best cut-off value for serum D-dimer to predict lower extremity DVT on the first postoperative day was 2.84 mg/L, the sensitivity was 70.1%, the specificity was 87.3%, and the area under the curve (AUC) was 0.815. The best cut-off value of D-dimer for predicting lower limb DVT on day 3 after surgery was 1.67 mg/L, sensitivity was 85.1%, specificity was 34.7%, and AUC was 0.611.

Patients with gastrointestinal malignant tumors have a high incidence of postoperative lower extremity DVT. When the serum D-dimer exceeds 2.84 mg/L on the first postoperative day, the likelihood of postoperative lower extremity DVT is higher.

Venous thrombosis; Stomach neoplasms; Colorectal neoplasms; Risk factors; D-dimer