Contemporary Safety Profile of Catheter-Directed Thrombolysis

BACKGROUND: Peripheral thrombolysis is an indispensible tool in the treatment of occlusive peripheral vascular disease (PVD). However, the use of intravascular thrombolytic agents carries a significant risk of morbidity and mortality. The aim of this study is to review a contemporary series of patients treated with catheter based thrombolytics in the treatment of occlusive PVD.
METHODS: A retrospective analysis was performed reviewing all patients who underwent catheter-directed thrombolytic therapy for PVD with tissue plasminogen activator (t-PA) from 2005 - 2008 at a single institution. Data included clinical and demographic variables potentially associated with endpoints of technical success (defined as complete thrombus removal and identification of underlying anatomy), hemorrhagic complications (defined as local and systemic, including stroke) and death. Data was analyzed with univariate and multivariate measures. Variables expressed as mean and standard error. Significance was assigned with P < 0.05.
RESULTS: Over the 36 month study, 125 thrombolytic procedures were performed. Indication for treatment was occlusive thrombus in native artery (49 cases, 37.6%), vein (13 cases, 10.4%) or arterial bypass graft (63 cases, 49.6%). 23 cases (14.3%) utilized ultrasound assisted catheter technology (EKOS EndoWave catheter system, Bothell, Washington). Mean patient age was 57.9 years ± 1.10 years. Technical success was achieved in 82% of cases. Mean t-PA dose was 47.3 ± 1.4 mg (13.5 ± 4.5 mg ultrasound assisted catheter technology, P < 0.05). Hemorrhagic complications occurred in 22.4% of patients with a 5.6% stroke rate. Hemorrhagic stroke was correlated with poor hypertensive control (systolic blood pressure >160 mmHg, OR 13.67, CI 1.59 - 117.68, P < 0.01) and advanced age (>80 years, OR 9.04, CI 1.40 - 58.57, P < 0.05). Hemorrhagic complications were correlated with poor hypertensive control (systolic blood pressure >180 mmHg, OR 3.48, CI 1.22 - 9.94, P < 0.05) and in patients with congestive heart failure (OR 3.26, CI 1.09 - 9.76, P < 0.05). Overall mortality occurred in 7 patients (5.6%), 4 as a result of hemorrhagic complication. Correlates of mortality were patients with diabetes mellitus (OR = 8.85, CI 1.62 - 48.26, P < 0.01), end stage renal disease (OR = 15.33, CI 2.07 - 113.39, P < 0.01) and congestive heart failure (OR = 6.06, CI 1.22 - 30.13, P < 0.01). Serum fibrinogen levels and t-PA dosage did not correlate with hemorrhagic complication or death.
CONCLUSIONS: Peripheral thrombolysis with catheter-based technologies has a high incidence of technical success. However, the procedure continues to carry a significant complication rate. This study emphasizes the importance of hypertensive control and identifies subgroups of patients at risk of untoward complications. t-PA dosage and fibrinogen levels had no correlation with hemorrhagic complications. Based on these data, the authors advocate stricter blood pressure parameters in patients undergoing peripheral thrombolysis.