Background: Venous thromboembolism (VTE) is known as one of the major complications in patients with malignant tumors and orthopedic disorders. Patients undergoing surgery for orthopedic oncology are at an increased risk for thromboembolic events. However, there are limited studies regarding the incidence and risk factors for preoperative VTE in orthopedic oncology patients.
Methods: The aim is to determine the incidence and risk factors of preoperative VTE by screening with D-dimer. We retrospectively reviewed the medical records of 270 patients who underwent surgical procedures, including biopsy for orthopedic oncology, had preoperative D-dimer levels measured and were subsequently screened for VTE by lower extremity venous ultrasonography and contrast-enhanced computed tomography (CT) scans if necessary. Statistical analyses were performed to examine the incidence and risk factors for VTE. Receiver operating characteristic (ROC) analysis was performed to verify the cutoff value of D-dimer for the diagnosis of VTE.
Results: A total of 199 patients (103 with primary soft tissue sarcomas, 38 with primary bone sarcomas, 46 with metastatic tumors and 12 with hematologic malignancies) were included. The value of D-dimer was high in 79 patients. VTE was detected in 19 patients (9.5%). Multivariate analysis indicated that, age ≥60 years (P = 0.021), and tumor location in the lower limbs (P = 0.048) were independent risk factors for VTE. ROC analysis showed that the cutoff value of D-dimer for the diagnosis of VTE was 1.53 µg/mL (sensitivity of 89.5% and specificity of 79.4%).
Conclusions: Our study indicated that age and tumor location in the lower limbs were independent risk factors for preoperative VTE in orthopedic oncology patients. D-dimer was not significantly different in the multivariate analysis because D-dimer is affected by a wide variety of conditions, such as malignancy and aging. Patients with high D-dimer levels and the abovementioned risk factors are at increased risk of preoperative VTE, and additional ultrasonography should be considered.
Trial registration: Our study was approved by the institutional review board. The registration number is B200600056. The registration date was July 13, 2020.