Significance of Distal Runoff Score as a Key Influencer on Clinical Outcomes after Endovascular Interventions for Superficial Femoral Artery Disease

Abstract

Endovascular therapy (EVT) is being adopted by many surgeons as a suitable first choice in the treatment of most femoropopliteal disease when clinically indicated. However, there are multiple factors affecting the outcome of EVT including the anatomy of lesions and distal runoff status. The evidence of runoff effect on the outcome of superficial femoral artery (SFA) interventions is still scarce and not well studied in the current literature. The aim of this study was to investigate the effect of runoff score on the outcomes of SFA endovascular interventions. Retrospective analysis was carried out on prospectively collected data on patients who underwent SFA endovascular intervention for critical limb ischemia (CLI) in a single tertiary center. Patients with Rutherford categories 4, 5, and 6 who did not have any previous vascular interventions were included in the study. The modified SVS runoff score was used after calculating scores from popliteal and all tibial vessels. Runoff was stratified into good (score <5), compromised (score 5-10), and poor (score >10). Amputation-free survival, patency rates, and overall survival were compared between all groups at 5 years. Between 2011 and 2018, 254 procedures were performed in 220 patients. Technical success was >92%; 66 patients required SFA stents, and 55 had concomitant tibial angioplasty. There was no significant difference between good, compromised, or poor runoff groups regarding complication rates, with 3.5% overall perioperative mortality (5 cases in the compromised group and 4 in the poor runoff group). A runoff score of <5 was associated with significantly marked clinical improvement (P<0.001). Patency rates were significantly worse in the compromised and poor runoff groups, with 5-year cumulative primary patency rates of 80%, 50%, and 22% in the good, compromised, and poor runoff groups, respectively (P<0.001). Amputation-free survival worsened as the runoff got poorer with 98%, 91%, and 78% in the good, compromised, and poor runoff groups, respectively, at 5 years (P<0.001). SFA stenting and concomitant tibial angioplasty led to slight improvement in patency rates in the poor runoff group. Poor runoff with a score of >10 was associated with significantly reduced amputation-free survival and patency rates at 5 years in patients undergoing SFA endovascular intervention for CLI. Patients with a runoff score of <5 showed marked clinical improvement postoperatively when compared with patients with a runoff score of ≥5.