Clinical evaluation of high-frequency (ultrasonic) mechanical débridement in the surgical treatment of calcific aortic stenosis

Abstract

Repair of aortic valve stenosis due to calcific degeneration may lead to hemodynamic and clinical improvement without the problems inherent with prosthetic valves. We have evaluated the use of a device capable of débriding calcium, the Cavitron ultrasonic aspirator (CUSA), as an adjunct to mechanical débridement in the repair of calcific aortic stenosis. Ten patients (five women), ages 63 to 83 years, were studied by M-mode, two-dimenslonal, and Doppler echocardiography before and an average of 26 (range 3 to 124) days after this procedure. The degree of calcification of the valve cusps was clearly reduced. The maximal cusp excursion increased from 0.7 ± 0.1 cm preoperatively to 1.5 ± 0.4 cm postoperatively ( p = 0.006). The peak aortic gradient fell from 80 ± 36 mm Hg to 28 ± 10 mm Hg ( p = 0.0007). The mean aortic gradient fell from 53 ± 20 mm Hg to 16 ± 5 mm Hg ( p < 0.0001). Aortic valve area calculated by the continuity equation increased from 0.6 + 0.2 cm 2 to 1.6 ± 0.6 cm 2 ( p = 0.0009). No patient had more than mild aortic insufficiency preoperatively. Postoperatively, color Doppler flow mapping revealed severe aortic insufficiency in two patients. Seven patients had further echocardiographic evaluation 99 (range 33 to 196) days after the procedure. These studies revealed the development of severe aortic insufficiency in an additional four patients. Four patients with severe symptomatic aortic insufficiency eventually underwent aortic valve repiacement. Pathology revealed scarring and retraction of the aortic cusps. Widening of the commissures was responsible for the severe aortic insufficiency. In conclusion, this proceduce results in a significant increase in the mobility of the valve cusps, with a decrease in the amount of calcium. There is a marked increase of the aortic valve area with a concomitant reduction of the aortic valve gradient. However, progressive, symptomatic aortic insufficiency frequentiy develops after the procedure due to scarring and retraction of the aortic cusps. We do not recommend this procedure for the treatment of calcific aortic stenosis.