Survival of Patients and Treatment-Related Outcome After Intra-Arterial Thrombolysis for Acute Lower Limb Ischemia.

Background: The aim of this study is to evaluate the long-term survival and treatment-related outcome in patients treated with intra-arterial thrombolysis for acute lower limb ischemia.

Methods: The study was based on a prospective vascular database with retrospectively obtained supplementary information from the patients' files. Additionally, data on the patients' date and cause of death were obtained from Statistics Finland. A total of 155 patients with symptoms or signs of category I-IIa acute lower limb ischemia and angiographic evidence of native artery or bypass graft thromboembolic events were treated with intra-arterial catheter-directed thrombolysis (CDT). Patients with severe ischemic stages at admission or those with contraindications for thrombolysis (n = 185) were treated with conventional surgical modalities and excluded from further analysis.

Results: The mean age of the patients at admission was 73 years (95% confidence interval 70.1-74.6). For descriptive purposes, age quartiles were used (≤64, 65-74, 75-82.5, ≥83). The mean follow-up time was 126.3 months. The primary patency rates of native arteries/bypass grafts were 59.8%/31.7%, 35.4%/17.1%, and 18.7%/15.2% at 1, 5, and 10 years, respectively (P = 0.01). Correspondingly, the respective secondary patency rates were 65.2%/55.6%, 46.7%/39.8%, and 22.8%/30.5% (P = 0.88). A total of 190 additional procedures on 122 patients were required to preserve the patency after hospital discharge. At 1 year the cumulative survival was 78%, at 5 years 56%, and at 10 years 29%. The most common cause of death was cardiovascular (68.5%), predominantly presented by an acute coronary syndrome, while 9.6% died of cancer, 6.8% of pulmonary diseases, 8.2% of cerebrovascular causes, and 19.2% owing to trauma and other reasons. Atrial fibrillation (hazards ratio [HR] 2.31) and age over 83 years (HR 5.23 per age category) were significantly and independently associated with poorer cumulative post-procedural survival. Bypass graft thrombosis was associated with an increase in major amputations after CDT (HR 14.77). However, the presence of synthetic bypass grafts had a protective influence on limb salvage (HR 0.086). A total of 39 (25.2%) major amputations were performed during the follow-up period. Age over 75 years was the only significant and independent factor to negatively impact on amputation-free survival (HR 2.01), which was 24% at 10 years.

Conclusions: The long-term patency after CDT is unfavorable, and additional procedures are needed to preserve adequate distal perfusion. Approximately 30% of the patients are alive at 10 years after the initial CDT. Increasing age and atrial fibrillation have a negative effect on the patients' survival.