Percutaneous mitral valvuloplasty--a new method for balloon sizing based on maximal commissural diameter to improve procedural results.

Background: Since the introduction of the Inoue technique for percutaneous balloon mitral valvuloplasty (PBMV), various criteria have been proposed for ideal balloon sizing. In routine practice, balloon size is chosen based on the patient's height according to a simple formula. We tried to define a simple and practical echocardiographic measure for adjusting balloon catheter size to achieve better success rates and fewer complications.

Methods: Patients with moderate to severe mitral stenosis who were candidates for PBMV were selected. Maximal mitral commissural diameter at a fully opened state during diastole was measured by transthoracic echocardiography and compared with the values from the height-based formula. Data were compared by paired sample t-test.

Results: Eighty-three patients (mean age 45±13.2 years; 77 female) participated. The median balloon size was 28 mm (standard deviation [SD] 1.2) according to the height-based formula and 26 mm (SD 1.6) according to echocardiography (p<0.001). Using a Bland-Altman plot, an excellent agreement was observed between the two methods. Regression models were fitted to estimate the balloon size using the patients' height, commissural diameter, and mitral valve score.

Conclusion: Selection of balloon size according to echocardiographic commissural diameter is a good alternative method. Assuming the possible discrepancy between height-based and commissural-based estimated balloon sizes in some cases, adjustment of balloon sizes according to the maximal commissural diameter may result in acceptable results and fewer complications.