The Drug-Coated Balloon and Primary Patency in Endovascular Therapy for Femoropopliteal Lesions With “Black Rock” Nodular Calcification

OBJECTIVE: Nodular calcifications occupying the lumen in the femoropopliteal artery, known as "Black Rock (BR)" lesions, are associated with poor patency. We focused on the drug-coated balloon (DCB) and examined whether the impact of final endovascular therapy (EVT) devices on primary patency differs by the BR lesions in the superficial femoral artery (SFA) to the proximal popliteal artery. DESIGN: Retrospective analysis of a prospective observational cohort study. METHODS: The study included 305 limbs in 224 patients who underwent EVT for SFA-proximal popliteal artery lesions. Final EVT devices included DCB in 137 limbs, drug-coated stent (DCS)/drug-eluting stent (DESs) in 87 limbs, and bare-nitinol stent (BNS) in 81 limbs. The primary endpoint was the 3-year primary patency. Kaplan-Meier analysis and multivariate Cox proportional hazard regression were performed to assess device-specific outcomes. RESULTS: There was a significant interaction between BR and DCB treatment to predict primary patency (p for interaction=0.002). Three-year Kaplan-Meier primary patency rates of the DCB, DCS/DES, and BNS groups were 67%, 71%, and 52%, respectively, in limbs without BR with a significant difference (p=0.006); 49%, 79%, and 75%, respectively, in limbs with BR with a significant difference (p=0.009). The multivariate Cox proportional hazards regression analysis showed that DCB treatment was associated with higher 3-year primary patency in limbs without BR (hazard ratio [HR]=0.35; 95% confidence interval [CI]=0.18-0.73; p=0.005), but with lower primary patency in limbs with BR (HR=3.09; 95% CI=1.20-7.94; p=0.019), after adjustment for confounding factors. CONCLUSION: Drug-coated balloon treatment was useful to maintain primary patency in limbs without BR, but its efficacy was limited in limbs with BR, indicating BR could be an additional information in optimizing final EVT devices.Clinical ImpactIn the absence of atherectomy, drug-coated balloons (DCBs) showed lower 3-year primary patency in heavily calcified nodular lesions ("Black Rock"). Furthermore, bare-nitinol stents (BNSs) and drug-eluting stents/drug-coated stents (DESs/DCSs) showed no significant difference in primary patency in heavily calcified lesions. These results suggest that the antiproliferative effect of paclitaxel may be limited in such lesions, highlighting the need for lesion-specific device selection to optimize long-term patency in femoropopliteal arteries.