High Embolic Risk With Orbital Atherectomy For Calcified Peripheral Artery Disease

PurposeOrbital atherectomy (OA) is used to treat heavily calcified peripheral artery disease, aiming to improve vessel compliance and reduce the need for high-pressure angioplasty and stenting. However, clinical data raise concerns regarding distal embolization, vessel injury, and uncertain long-term benefit. MethodsThe biomechanical and embolic effects of OA were evaluated in 10 human femoropopliteal arteries with advanced atherosclerosis and calcification. A pulsatile flow loop replicated physiologic hemodynamics. Sequential OA and balloon angioplasty (BA) were performed, followed by CT to quantify luminal changes. Pressure and flow sensors assessed translesional gradients and flow rates. Embolic burden was captured via 100m filters and quantified using image analysis. Arterial pulsatility was evaluated using duplex ultrasound and optical imaging. ResultsOA and BA produced additive luminal gains (total increase: 0.409mL) but frequently caused dissections. OA generated substantial embolic debris (mean area 0.386{+/-}1.654mm2), with 90% of arteries releasing fragments [≥]1mm and 10% >5mm. BA added smaller debris (0.143{+/-}0.361mm2). Translesional pressure gradients decreased in 40% of arteries, showed no improvement in 50%, and worsened in 10%. Net flow followed a similar pattern: improved in 40%, unchanged or decreased in 60% due to dissections or distal obstruction. Inner diameter (ID) pulsatility increased from 1.5%{+/-}0.7% to 2.3%{+/-}0.5%, while outer diameter pulsatility remained unchanged. ConclusionsOA improves lumen volume and ID-based pulsatility but consistently produces large emboli and vessel wall injury. These findings provide mechanistic support for the high embolic complication rates and mixed long-term outcomes observed clinically, emphasizing the importance of embolic protection and careful patient selection.