Correlation between the preoperative maximum soleal vein diameter and the postoperative bilateral deep venous thrombosis in THA: a case–control study

BACKGROUND: Patients with bilateral lower limb deep venous thrombosis (DVT) have a higher risk of pulmonary thromboembolism (PTE) and mortality than patients with unilateral lower limb DVT. Preoperative dilatation of the soleal vein (SV) diameter is a predictor of postoperative DVT. The purpose of this study is to investigate the cutoff value for SV diameter as a risk factor for VTE development. MATERIALS AND METHODS: The authors examined 274 patients with unilateral THA who met the inclusion criteria in a retrospective study. The mean age of the patients was 65.7±11.2 years, with 70 males and 204 females. Bilateral lower limb vein ultrasonography was performed preoperatively and ~1 week after THA. The frequency and localization of DVT were investigated in postoperative ultrasonography. The patients were divided into three groups: no DVT (non-DVT), unilateral lower limb DVT (Uni-DVT), and bilateral lower limb DVT (Bi-DVT). The three groups were compared in terms of preoperative venous vessel maximum diameter. RESULTS: There were 62 patients (22.6%) who had postoperative DVT. There are no symptomatic PTE patients. DVT was found in 44 patients (16.0%) of the Uni-DVT group and 18 patients (6.6%) of the Bi-DVT group. The SV maximum diameter was 6.41±1.79 mm in the non-DVT group, 7.06±2.13 mm in the Uni-DVT group, and 8.06±2.26 mm in the Bi-DVT group, with a significant difference (P=0.001) between the non-DVT and Bi-DVT groups. In the Bi-DVT group, the cutoff value for preoperative SV maximum diameter was 6.75 mm (95% CI: 0.625–0.831; P=0.001; sensitivity, 77.8%; specificity, 60.4%; area under the curve, 0.728). CONCLUSIONS: In THA, preoperative ultrasonography with a maximum SV diameter of 6.75 mm or greater was the risk of bilateral DVT leading to fatal PTE is increased.