Effect of IV Iloprost on Distal Flow in Buerger's Disease: Correlation with CT Perfusion

Objectives: Revascularization in thromboangiitis obliterans (TAO) is limited by distal small-vessel involvement and poor blood flow; no curative treatment exists. This study aimed to evaluate the effect of intravenous iloprost (IVI) on distal perfusion using computed tomography (CT) perfusion imaging and to correlate perfusion changes with clinical outcomes, with a focus on treatment duration. Methods: This retrospective cohort study was conducted at a single tertiary cardiovascular surgery center. Thirty-three patients (32 men and 1 woman) with confirmed TAO treated with IVI were screened. Clinical data, including ankle-brachial index (ABI), claudication distance, and pre- and post-treatment CT perfusion parameters, were obtained from outpatient records. Patients were grouped according to IVI duration: 0 days (n = 8), 7 days (n = 7), 14 days (n = 10), and 21 days (n = 8). One patient was excluded due to incomplete data, leaving 32 patients for analysis. Results: IV iloprost therapy resulted in significant improvements in ABI, claudication distance, and CT perfusion parameters, particularly in the 14- and 21-day treatment groups. No statistically significant differences were observed between the 14- and 21-day regimens; however, both were superior to shorter or no treatment. The 21-day group demonstrated the most consistent overall improvement. Treatment efficacy was independent of active smoking status, and patients with baseline ABI > 0.8 showed a more favorable response. Conclusions: Intravenous iloprost is clinically effective in TAO patients. Improvements in CT perfusion strongly correlate with ABI and claudication distance, suggesting that CT perfusion may serve as an early marker of treatment response and a useful adjunctive tool in TAO assessment.