Outcomes and predictors of failure of thrombolysis for iliofemoral deep venous thrombosis

Background Catheter-directed thrombolysis (CDT) with adjunctive mechanical techniques, when successful, is reported to alleviate symptoms of acute iliofemoral deep venous thrombosis (IFDVT) and to lower the occurrence of the post-thrombotic syndrome (PTS). This study aimed to determine longer term outcomes of catheter-based interventions for IFDVT and to identify predictors of immediate and mid-long-term failures that would guide optimal patient selection.

Methods Consecutive patients who underwent CDT or pharmacomechanical thrombolysis for IFDVT between May 2007 and March 2013 were identified from a prospectively maintained database. Assessment of predictors of immediate periprocedural failure was based on the degree of clot lysis (≤&50% vs ;gt&50%) and 30-day recurrence of DVT. Long-term anatomic and clinical failures and outcomes were assessed by ultrasound imaging of the lysed segments and Villalta score (≥5 vs ;lt&5). Survival analysis was used to assess primary patency and PTS morbidity. Multivariate binary logistic and Cox regression models were used to determine predictors of anatomic and clinical failures.

Results During the study period, 93 patients (118 limbs; mean age, 49.4 ;plusmn16.2 years; 47 women) with symptoms averaging 11.1 ;plusmn9.6 days in duration were treated with various combinations of CDT or pharmacomechanical thrombolysis; in 52 (56%), at least one iliocaval stent was deployed. Immediate treatment failure was seen in 11 patients (12%) predicted by the preoperative indication "phlegmasia" (odds ratio, 3.12; P =.042) and recent surgery (odds ratio, 19.6; P =.018). At a mean ultrasonographic follow-up of 16 ;plusmn14 months (range, 1-65 months), six more patients sustained a rethrombosis, accounting for an overall 3-year primary patency of 72.1%. In the long-term model, loss of primary patency was associated with recent surgery (hazard ratio [HR], 4.04; P =.023), malignant disease (HR, 6.75; P =.016), and incomplete thrombolysis (≤;50%) (HR, 5.83; P <.001). By stratification of PTS on the basis of postprocedure failures, at 2 years PTS occurred in 50.6% of patients and in 16.3% of patients without failure (P <.001).

Conclusions Thrombolysis for symptomatic IFDVT can achieve high rates of thrombus resolution and reduce long-term PTS morbidity on careful patient selection. Improved anatomic and clinical outcomes are associated with the completeness of thrombolysis.