Sizing of balloons in balloon mitral valvotomy.

ABSTRACT

In twenty six consecutive patients who underwent balloon mitral valvotomy (BMV) by the transseptal double balloon technique, the mitral valve area (MVA) increased from 0.78 +/- 0.1 cm2 to 1.80 +/- 0.3 cm2, (p < 0.001). Effective balloon dilating area (EBDA) of each combination of balloons used was calculated using a standard formula. Patients were classified into 4 subgroups with approximate EBDAs of 3.3, 4.0, 4.9 and 5.7 cm2 and they had mean post-BMV MVAs of 1.28, 1.78, 1.89 and 1.98 cm2 respectively (ANOVA F = 3.32, p < 0.05). Patients were reclassified after normalisation of EBDA and post-BMV MVA to square metre of body surface area. Three subgroups with mean normalised EBDAs of 2.32, 2.96 and 3.62 cm2/m2 had mean normalised post-BMV MVAs of 0.99, 1.17 and 1.40 cm2/m2 respectively (ANOVA F = 6.85, p 0.01). A trend towards increasing mitral regurgitation with increasing balloon size was noted. Three cases of mitral regurgitation including one case of severe mitral regurgitation occurred in the subgroup of 9 patients with largest normalised EBDAs. The overall correlation between normalised EBDAs and normalised post BMV MVA was strong r = 0.67, p < 0.01). The optimal normalised EBDA for Indian patients undergoing BMV is around 3.6 cm2/m2. Balloons used should be sized accordingly.