Large series of patients with symptomatic mitral stenosis have undergone percutaneous mitral balloon valvuloplasty(PMV) with use of the Inoue or double balloon technique. But to date the result of the two procedure have not been compared with a single series prospectively.

In order to assess the immediate hemodynamic results and the longterm efficacy of two different PMV technique, a prospective, randomized trial of PMV was performed using the Inoue balloon(Toray, I group) in 59 patients and the double balloons(a pair of Mansfield balloon. D group) in 61 patients with moderate to severe mitral stenosis. Before valvuloplasty, the patients series were comparable with regard to average age. gender, most clinical and echocardiographic variables. All the patients(120 patients, M/F 38/82, mean age 41±11 year) were preselected with good echoscore≥9.

The success rate was 83% in the I group and 89% in the D group when the success defined as mitral valve area(MVA)≥1.5cm² with 25% gain in MVA and mitral regurgitation≥2+ at the end of procedure. The magnitude of increase of mitral valve area and decrease of mitral gradient, left atrial pressure and pulmonary arterial pressure were not significantly different in the Inoue and double balloon series(1.0±0.4 and 1.1±0.4cm² for mitral vale area, 10.2±6.6 and 11.7±6.4mmHg for mitral gradient, 10.5±6,4 and 12.9 ±7,3mmHg for left atrial pressure, and 8.7±7.3 and 10.1±9.4 mmHg for pulmonary artrial pressure respectively). Immediatly after dilation, the long diameter changes of the mitral orifice was more prominent in the D group(from 1.0±0.2 to 2.6±0.4cm p<0.01) than those in I series(from 1.1±0.4 to 2.3±0.3cm) Moreover, the magnitude of increase in the EF slop was significantly larger in the D group(31.9±17.0 vs 21.8±14.2mm/sec, p<0.001). The duration of total procedure(56±20 vs 84±24 min, p<0.002) and the fluoroscopic time (15±6 vs 25±11min, p<0.002) was significantly shorter in group I. The incidence of left to right shunt at the atrial level(Qp/Qs>1.5) was 3.4% in group I and 4.9% in group D. Severe mitral regurgitation≥3+ occurred in 2 patients in each I(3.4%) and D(3.3%) group respectively. At follow-up, the mitral valve area was significantly decreased(1.6 in group I vs 1.8cm² in group D, P<0.001 vs immediate after MVA) at 6 months and well maintained at 1 year follow-up in both groups. Until 6 months after valvuloplasty, the long diameter of orifice was greater in group D, however the difference was not apparent at 1 year follow-up.

The Inoue and double balloon techniques obtained equivalent results of the success rate and the frequently of complications. However, the Inoue balloon technique reduced significantly fluoroscope time and total procedure duration. Double balloon technique afforded a longer longitudinal splitting of the commissure immediatly and 6 months after valvuloplasty. However the differences was not apparent at 1 year follow-up. Increased MVA was well maintained at 1 year in both groups. The severity of the newly developed mitral regurgitation immediately after valvuloplasty reduced significantly in 53% of the Inoue and 43% in the double balloon group at 6 months follow-up. In the view point of similiar immediate and late results of the two methods, the stepwise dilation with Doppler echocardiographic monitoring during the Inoue procedure appeared to be cumbersome.