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

The manner in which aortic valve area increases after in vitrodouble balloon aortic valvotomy for severe rheumatic aorticstenosis has not been defined. We selected ten intact aorticvalves excised at cardiac surgery from patients (mean age 45± 10 years) with severe rheumatic aortic stenosis, witha valve area cm². In vitro double ballon aortic valvotomy wasattempted on each valve using two Meditech 15 mm diameter ballooncatheters. The balloon catheters were simultaneously inflatedto 4 atm pressure for 10 s. Before and after balloon valvotomythe valve area was calculated with a conical sizer, and radiologicalstudies were also performed to study the effect of balloon valvotomyon calcified aortic commissures. The mean valve area increasedfrom 0.7 ± 0.2 (mean ± SD) to 1.1 ± 0.2cm² (P0.001) after balloon valvotomy, with a mean total commissuralsplit ting for each aortic valve of 9.3 ±6 mm. Overall,63% of the aortic commissures were split, splitting occurringin 81% of non-calcified commissures and 43% of calcified commissures.There was no leaflet tear or calcium fracture either macroscopicallyor radiologically. Commissural splitting of rheumatic aorticstenosis is the manner in which valve area is increased afterdouble balloon aortic valvotomy. The inflated balloon catheterssplit 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 aorticvalvotomy technique may become a palliative therapeutic procedurefor patients with severe rheumatic aortic stenosis.