Objectives: This study used pre-rotational and post-rotational atherectomy volumetric intravascular ultrasound analysis to determine whether rotational atherectomy causes ablation of non-calcified atherosclerotic plaque.
Background: Rotational atherectomy is currently the preferred treatment for heavily calcified coronary lesions. However, the mechanism of lumen enlargement in noncalcified lesions has not been studied in detail. Intravascular ultrasound allows detailed, cross-sectional imaging of the coronary arteries in vivo. The normal coronary artery wall, the major components of the atherosclerotic plaque and the quantitative changes in vessel, lumen and plaque cross-sectional areas and volumes that occur as a result of the atherosclerotic disease process and during transcatheter therapy can be studied in a manner otherwise not possible.
Methods: Eighteen noncalcified native vessel lesions in 18 patients were imaged before and after rotational atherectomy using intravascular ultrasound systems incorporating motorized transducer pullback through a stationary imaging sheath. External elastic membrane, lumen and plaque plus media cross-sectional areas were measured every 1 mm of lesion length (for a total of 10 image slices), and external elastic membrane, lumen and plaque plus media volumes were calculated using Simpson's rule.
Results: After rotational atherectomy, the minimal lumen cross-sectional area increased from 1.37 +/- 0.50 to 2.99 +/- 0.60 mm2 (mean value +/- 1 SD, p < 0.0001). Lumen volume increased from 23.2 +/- 9.0 to 38.0 +/- 8.0 mm3 (p < 0.0001) as a result of a decrease in plaque plus media volume (from 102.2 +/- 50.9 to 85.8 +/- 47.7 mm3, p < 0.0001), with no change in total vessel (external elastic membrane) volume (125.3 +/- 54.2 to 123.8 +/- 52.9 mm3, p = 0.119).
Conclusions: Rotational atherectomy effectively ablates noncalcified plaque in non-calcium-containing lesions.