Percutaneous mitral commissurotomy with a metallic dilator. A multicenter investigation in 500 patients.

A clinical investigation has been conducted since January 1996 with a new v alve dilator for percutaneous treatment of mitral stenosis : metallic commi ssurotome. This new technique is based on the principle of surgical commiss urotome 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 50 0 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 ca ses (98%) with a success rate (mitral area > 1.5 cm(2) 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 cm(2). Complications were uncommon (13 pat ients : 2.6%) and consisted in 6 tamponnades, 5 mitral insufficiences (one patient required an emergency valve replacement) and 2 neurogical 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 o f experience with this technique. Considering the possibility to reutilize the metal segments of the apparatus, this technique notably reduces the cos t of the procedure per patient and it represents a significant benefit in c ountries with limited ressources.