Histological features of restenosis associated with paclitaxel drug-coated balloon: implications for therapy.

PURPOSE: To investigate the cellular and extracellular changes induced by drug-coated balloons (DCB) in the treatment of superficial femoral artery (SFA) restenosis, and to compare histopathological features with those observed after plain old balloon angioplasty (POBA) from the same patients.

METHODS AND RESULTS: Plaque samples for five patients with SFA restenosis (first-time) after POBA were collected using atherectomy and DCB. These samples constitute the POBA restenosis group. The same five patients developed recurrent restenosis (RR) after DCB, at the same intervention site. These SFA-RR lesions were again treated using atherectomy and POBA. These samples constitute the DCB restenosis group. DCB restenosis group plaques showed significant reduction in neointima, smooth muscle cells, fibroblast densities, and Ki67 index; and increase in caspase 3, features of apoptosis and type III collagen deposition in comparison to the POBA restenosis group.

CONCLUSION: Plaque tissue from the DCB restenosis group show reductions in neointimal thickness, cellularity, and cellular proliferation, along with increased apoptosis, and Type III collagen content. These results suggest a different mechanistic pathway for DCB restenosis, in which neointimal proliferation is reduced but reparative fibrosis is increased. The treatment for SFA-RR after DCB may therefore benefit from different forms of therapy including scaffolding, rather than recurrent anti-proliferative therapy.