Peripheral plaque volume changes pre- and post-rotational atherectomy followed by directional plaque excision: assessment by intravascular ultrasound and virtual histology.

Atherectomy in the infra-inguinal peripheral vascular bed may be an effective alternative to the balloon and stent-based approach. The change in plaque volume and composition with rotational atherectomy and directional plaque excision has not been studied. We performed rotational atherectomy (RA) followed by adjunctive plaque excision (PE) in 8 patients with infra-inguinal lesions. Lesions were assessed by quantitative angiography and intravascular ultrasound (IVUS) with virtual histology (VH) pretreatment, post-RA, and post-PE. Paired t-tests were used to assess the change in plaque volume, luminal area and dimensions and overall vessel size. Total plaque volume decreased by 24% (347 +/- 118 to 264 +/- 85 mm(3); p = 0.03), which resulted in a lumen increase of 66% (7.08 +/- 3 to 11.7 +/- 2.8 mm(2); p = 0.006). This was mainly due to PE compared to RA. This was achieved without any significant increase in the overall vessel area (27.4 +/- 6.3 to 28 +/- 6.7 mm(2); p = 0.42). The effect on minimal and maximal luminal diameters was synergistic between RA and PE. Fibrotic and fibrofatty plaque were amenable to PE, whereas necrotic core and dense calcium were less responsive to either atherectomy technique. In conclusion, RA followed by PE result in significant improvements in plaque volume and luminal area and diameter primarily by removing plaque rather than vessel expansion. This is mainly attributable to the removal of fibrotic and fibrofatty plaque.