Efficacy of percutaneous mitral balloon valvuloplasty with the inoue balloon. Percutaneous mitral balloon valvuloplasty has become an accepted technique for use in selected patients with severe, symptomatic mitral stenosis. Recently, a new balloon catheter with an "hourglass" shape and specially designed guidewires and dilators has become available (Inoue balloon). The design of this balloon provides ease of manipulation and self-stabilization across the mitral valve during inflation. These features should decrease the incidence of complications associated with the procedure. Preliminary results in 12 consecutive patients who underwent percutaneous mitral balloon valvuloplasty with the Inoue balloon are presented. The mitral valve area increased from 0.92 +/- 0.21 cm2 before the procedure to 1.75 +/- 0.40 cm2 after the procedure. No complications occurred from the procedure, including no increase in severity of mitral regurgitation or creation of an atrial septal defect. Further follow-up is necessary to determine the long-term efficacy with this new balloon. Nonetheless, the preliminary results are encouraging. 