Enhanced Plaque Modification of Cadaveric Human Calcified Peripheral Arteries Treated with a Dynamic Scoring Catheter

Background: Calcific atherosclerosis is a major challenge to intraluminal drug delivery treatments in peripheral artery disease. We evaluated the effects of dynamic scoring on the surface morphology of calcified peripheral arteries.

Methods: Diagnostic imaging of 2 fresh human cadaveric lower limbs revealed mild to severe calcification in all main arteries. A total of seven arterial segments (1 peroneal, 2 SFA and 4 tibial) were treated 2-4 times using a Flex Dynamic Scoring catheter (DSC) under fluoroscopy and simulated flow. The FLEX was re-sheathed between treatment cycles, advanced back to the treatment site, and rotated 30°between each pass. Post treatment angiography confirmed vessel patency. Explanted arterial segments were processed for cross sectional histopathology and surface mapping by SEM.

Results: Histology revealed extensive evidence of vascular disease in all sections that included circumferential medial calcification with thin to moderate neointima, and asymmetric to nodular neointimal proliferation with variable calcification. Treatment effects were evident in all arterial segments, with scoring most commonly restricted to superficial neointima, sometimes extending through the IEL or, together with fracture/displacement of calcified lesions, involving the full-thickness of the wall. SEM revealed superficial to deep linear intimal scoring tracks that ran almost parallel to each other and extended along the length of the luminal surface (Fig).

Conclusions: Dynamic scoring of calcified peripheral arteries resulted in continuous linear surface tracks, whose circumferential spacing and depth can be controlled by the number of passes, catheter rotation and basket expansion. Future studies will evaluate the influence of DCS on adjunct drug delivery.