[In vitro study of transvenous commissurotomy in severe mitral valve stenoses using the balloon catheter].

To answer the question whether mitral commissurotomy with a balloon catheter is possible, the following in vitro study was performed. In 12 patients who were operated due to severe mitral stenosis the fibrotic (n = 8) or calcified (n = 4) valves were excised and mounted in a glass cylinder. In a first step a valvuloplasty was performed with a balloon catheter (size 20 mm). Mitral valve area increased by about 40%. With simultaneous inflation of a second balloon catheter (size 15 mm) valve area increased more than 100% and reached 1.63 cm2 in the mean. Valvuloplasty was successful (increase of at least 0.5 cm2) in 11/12 cases. In 9 valves the rupture occurred within the commissures, twice within the leaflets and once the opening area increased due to dilatation. Commissurotomy with a balloon catheter seems to be possible even in calcified mitral valves although in most cases a mild to moderate stenosis will remain.