Evaluation of in vivo morphological results of balloon mitral valvotomy

Percutaneous valvotomy is now more often considered for the treatment of mitral stenosis in poor risk patients. The aim of this study was the evaluation of the morphological changes produced by a similar procedure on the mitral valves of nine nonconsecutive patients undergoing a mitral valve replacement because of calcific isolated or prevalent mitral stenosis. The mitral valve was dilated through the left atriotomy before the valve excision with the same balloon catheter used in the percutaneous procedure. The pathological condition of the valve had been studied before dilatation by means of doppler echocardiography, cardiac catheterization and a visual examination performed by the surgeon before insertion of the balloon. At that time, the orifice area was measured with a Hegar dilator. A new measurement was performed after one or two dilatations performed at a balloon pressure of 2.7 atm. After excision, the valve was examined, photographed and X-rays were taken for evaluation of valve calcification. The pre-dilatation mean mitral valve orifice area was 1.3 +/- 0.4 cm2 and after the procedure was 2.8 +/- 0.3 cm2. In only one patient did the orifice area, originally 2.4 cm2, not increase. There was only one fused and calcified commissure, the other was normal. Before dilatation, the two commissures were fused in 17/18 cases and in 9/18, calcified. After dilatation, 5/17 commissures were completely open (not all were calcified), 10/17 incompletely opened and 2/17 remained fused (one in the above-mentioned patient).(ABSTRACT TRUNCATED AT 250 WORDS)