[Percutaneous mitral commissurotomy by metallic dilator. Multicenter experience with 500 patients].

A clinical investigation has been conducted since January 1996 with a new valve dilator for percutaneous treatment of mitral stenosis: metallic commissurotome. This new technique is based on the principle of surgical commissurotome but, in its mechanism of action, differs from the usual techniques with balloon catheters. It also offers the unique possibility for multiple utilizations of the same device after resterilization. This article reports a multicenter international investigation involving 500 patients, mean age of 34 +/- 13 years, with a isolated mitral stenosis and an echography score of 7.7 +/- 1.9. Our technique has been feasible in 489 cases (98%) with a success rate (mitral area > 1.5 cm2 without MR > grade 2) of 93%. The transmitral gradient has diminished from 20 +/- 8 mmHg to 4 +/- 3 mm Hg and the mitral area (assessed by planimetry at 24 hrs) has increased from 0.91 +/- 0.20 to 2.12 +/- 0.34 cm2. Complications were uncommon (13 patients: 2.6%) and consisted in 6 tamponades, 5 mitral insufficiencies (one patient required an emergency valve replacement) and 2 neurological transient accidents. The outcomes of this clinical investigation appear most encouraging and at least comparable to those being reported with the commonly used techniques. The most serious complications appear to be closely related to the level of experience with this technique. Considering the possibility to reutilize the metal segments of the apparatus, this technique notably reduces the cost of the procedure per patient and it represents a significant benefit in countries with limited resources.