Early Changes in Minimal Luminal Diameter After Balloon Angioplasty and Directional Coronary Atherectomy.

Early elastic recoil has been implicated in the pathophysiology of restenosis after balloon coronary angioplasty (PTCA). Directional atherectomy (DCA) may significantly attenuate this vessel wall reaction by altering the vessel wall architecture, specifically by removing or injuring the medial smooth muscle cells. We compared the magnitude of early changes in minimal lumen diameter (MLD) after DCA followed by adjunctive PTCA (group I) in comparison to PTCA alone (group II). In two groups of 30 lesions, matched for vessel size and location, group I cases showed significantly less recoil than group II cases, as assessed by routinely performed 15 minute post-procedure angiograms: mean changes in post-procedure MLD +0.06mm (increase) vs. -0.31mm (decrease) respectively, p = 0.02. In a histopathologic substudy of the DCA treated patients, those without early recoil had significantly higher incidence of media removal compared to patients with recoil (50% vs. 7%, p = 0.03). Therefore, early changes in MLD, presumably related to elastic recoil, are less with DCA and adjunct PTCA in comparison to PTCA alone. Attenuation of early recoil may be an additional mechanism accounting for the acute lumen gain achieved with this technique.