Risk factors for residual thrombosis in patients with deep vein thrombosis

Abstract

Deep vein thrombosis (DVT), which is no longer rare, is a disease in which a thrombus forms in veins. However, the risk factors for residual thrombus have not been fully investigated nor reported. In this study, we analyzed the risk factors for residual thrombus in patients with DVT and investigated whether the prognosis of thrombus can be predicted. The subjects were 114 patients in whom thrombosis was found by ultrasonography, and the thrombus was monitored by a second ultrasonography. We retrospectively collected patient characteristics, ultrasonography-related information, and thrombosis risk factors and scores. The patients were classified into two groups, namely, those with residual thrombus and those with thrombus disappearance, and then compared. Among all the patients, gender, age, treatment, and examination interval were found significant by multivariate analysis. Regarding patients who received treatment, there was a significant difference in examination interval and thrombosis risk score as determined by multivariate analysis. For those with no treatment, there was a significant difference in age as determined by multivariate analyses. Thrombus remained significant in patients with a high thrombosis risk score, showing that the thrombosis risk score is also useful for predicting residual thrombus. Of the thrombosis risk score items, there was a significant difference in bedridden state. Patients with thrombus retraction are reported to have significantly less severe sarcopenia and significantly thicker gastrocnemius muscles. Thus, a bedridden state should lead to muscle weakness due to sarcopenia and may be a risk factor for residual thrombus. In addition, it is presumed that the significant residual thrombus in the elderly is also related to the thickness of the gastrocnemius muscles. The present study indicated the possibility of predicting the prognosis of residual thrombus.