Double balloon aortic valvotomy for rheumatic aortic stenosis; in vivo studies

The manner in which aortic valve area increases after in vitro double balloon aortic valvotomy for severe rheumatic aortic stenosis has not been defined. We selected ten intact aortic valves excised at cardiac surgery from patients (mean age 45 +/- 10 years) with severe rheumatic aortic stenosis, with a valve area less than or equal to 1 cm2. In vitro double balloon aortic valvotomy was attempted on each valve using two Meditech 15 mm diameter balloon catheters. The balloon catheters were simultaneously inflated to 4 atm pressure for 10 s. Before and after balloon valvotomy the valve area was calculated with a conical sizer, and radiological studies were also performed to study the effect of balloon valvotomy on calcified aortic commissures. The mean valve area increased from 0.7 +/- 0.2 (mean +/- SD) to 1.1 +/- 0.2 cm2 (P less than or equal to 0.001) after balloon valvotomy, with a mean total commissural splitting for each aortic valve of 9.3 +/- 6 mm. Overall, 63% of the aortic commissures were split, splitting occurring in 81% of non-calcified commissures and 43% of calcified commissures. There was no leaflet tear or calcium fracture either macroscopically or radiologically. Commissural splitting of rheumatic aortic stenosis is the manner in which valve area is increased after double balloon aortic valvotomy. The inflated balloon catheters split not only non-calcified, but also calcified arotic commissures. The adequate commissural splitting achieved and consequent 57% increase in valve area indicate that the double balloon aortic valvotomy technique may become a palliative therapeutic procedure for patients with severe rheumatic aortic stenosis.