Contemporary criteria for the selection of patients for percutaneous balloon mitral valvuloplasty.

Commissural fusion is now recognised as the principal pathology underlying mitral stenosis, and commissural splitting underlies successful interventional treatment. Although the technique of surgical commissurotomy was first described as early as 1948, percutaneous commissurotomy became a feasible option with the advent of the Inoue balloon in 1984. Percutaneous balloon mitral valvuloplasty (PBMV) is now the treatment of choice for many patients with symptomatic mitral stenosis. Numerous large series have reported excellent short, medium, and long term outcome with a low incidence of serious complications. Furthermore, randomised trials comparing balloon valvuloplasty with the surgical alternatives of open or closed commissurotomy have demonstrated equivalent outcome, 10 although patients treated using the percutaneous approach enjoy the advantages of reduced procedural morbidity and mortality and a short hospital stay. Specific advantages of the Inoue balloon in comparison with other percutaneous techniques include a lower risk of complications (particularly left ventricular perforation which is more frequent using double balloon techniques), easier manoeuvrability, its slender profile (creating a smaller defect in the interatrial septum), its self positioning characteristics, short inflation–deflation cycle, and capacity to permit gradually increasing successive balloon inflation sizes, which allow the operator to terminate the procedure when commissural splitting is achieved or when there is an increase in the severity of mitral regurgitation. Disadvantages include circumferential application of pressure during balloon inflation, occasionally resulting in paracommissural tears, especially in degenerate, calcified valves. In developing nations, the application of PBMV is frequently limited on account of the high cost of the Inoue balloon. The development of a percutaneous metallic valvulotome, which can be autoclaved after each procedure to allow repeated use in many patients, may help to overcome these problems. Further potential advantages include a greater increase in valve area in comparison with the Inoue balloon, and selective commissural splitting, especially in calcified valves with a reduction in leaflet trauma. Initial data have been encouraging 12 but we must await multicentre experience and the results of ongoing assessment in randomised controlled trials. Given the success of PBMV, its applications are now expanding to include several categories of patients previously considered ineligible for the procedure. Nevertheless, the need for careful selection of appropriate patients remains paramount. In this article, we review the characteristics which need to be addressed and contemplate alternative approaches to be considered in certain circumstances.