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 >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 <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 ± 16.2 years; 47 women) with symptoms averaging 11.1 ± 9.6 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 ± 14 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.