“Balloon impasse”: A marker for severe mitral subvalvular disease and a predictor of mitral regurgitation in inoue‐balloon percutaneous transvenous mitral commissurotomy

In certain instances of percutaneous transvenous mitral commissurotomy, the Inoue catheter balloon, although deflated and properly aligned, becomes held up or checked at the mitral valve. This "balloon impasse," observed in 13 of 760 patients undergoing the commissurotomy, reflects severe obstructive subvalvular disease even though echocardiographic evidence suggests otherwise. Our experience shows that the sign portends severe mitral regurgitation if the usual balloon sizing method is used. Such a situation occurred with four of the first six patients. In the next seven patients, the use of smaller balloon catheters (PTMC-18 or PTMC-20) for the initial set of stepwise dilatations averted creation of severe mitral regurgitation. When the "balloon impasse" sign is encountered during the commissurotomy procedure, the catheter selection and balloon sizing method should be judiciously altered.