Long Term Follow Up, Causes for Re-intervention, and Consequences for Surveillance After Stenting for Proximal Deep Vein Obstruction

Abstract

Venous stenting is performed increasingly for acute deep vein thrombosis (DVT) and post-thrombotic syndrome (PTS) with good short term patency results, but long term data are scarce. The purpose of this study was to evaluate long term outcome of stenting for acute DVT and PTS and to study causes of re-intervention. All patients stented for acute DVT and PTS between May 2006 and November 2021 were included retrospectively in this single centre cohort study. Patency was studied by duplex ultrasound (DUS) or computed tomography. The primary endpoint was stent patency. Re-intervention free survival was calculated using Kaplan-Meier methods. Secondary endpoints were causes of re-intervention, using the Pouncey classification system (2022). Binary logistic regression was used to calculate odds ratios for predictors of re-intervention. A total of 114 patients were included, with 129 limbs involved (acute DVT n= 53; 41%), PTS n= 76; 59%). Median follow up was 2.3 years (interquartile range [IQR] 2.3) for acute DVT and 5.2 years (IQR 7.1) for PTS. Primary patency, secondary patency, and permanent occlusion were 73.5%, 98.1%, and 1.9% for acute DVT, and 63.2%, 92.1%, and 7.9% for PTS limbs. Overall, 41 limbs underwent at least one re-intervention: 14 in the acute DVT group and 27 for PTS. Most re-interventions (82.9%) were performed within the first year after stenting. Missed inflow, insufficient flow, and thrombosis despite anticoagulation were the most common causes of re-intervention. The strongest predictor for re-intervention for PTS was inflow disease (odds ratio 3.57, 95% confidence interval 1.26 - 10.13, p= .017). Long term patency of deep venous stenting is good. Re-interventions are typically performed in the first year and are potentially preventable by improving the procedure and patient selection. Since secondary patency rates are excellent, selected patients may be considered for discharge from long term surveillance.