Valvuloplasty with trefoil and bifoil balloons and the long sheath technique

The experimental and early clinical experience with percutaneous valvuloplasty using trefoil and bifoil balloon catheters (Schneider Shiley) and a long introducer sheath with a new back-up wire are reported. The trefoil balloon consists of three and the bifoil balloon of two angioplasty balloons mounted in parallel on a single catheter. Inflated, they form a rosette allowing for some blood flow through the spaces between the individual balloons. These small balloons are more pressure tolerant than one large balloon. The hemodynamic advantage of these balloons compared to single balloons could be demonstrated in animal experiments (healthy valves and surgically created stenoses). In 31 consecutive patients with trefoil-bifoil balloon valvuloplasty, there was no inhospital mortality. The results of trefoil valvuloplasty in twelve patients with pulmonary stenosis compared favorably to those of patients treated with single balloons. There were no technical failures or complications. There were two unsatisfactory results (severely dysplastic valve). In the aortic valve, the results with calcified stenoses were satisfactory at first but disappointing during follow-up. There were no technical failures but one of nine patients suffered an embolic myocardial infarction. In the mitral valve, there were two failures (one deficient equipment, one stroke during balloon positioning). In one case, insufficient balloon size led to an inadequate result. One patient needed surgical drainage for a pericardial tamponade. In two patients, mitral regurgitation was significantly increased. A 17F long sheath was developed to further facilitate balloon valvuloplasty. It guides the balloon catheter across the valve (and across the septum in case of the mitral valve), stabilizes it during inflation, and serves as a second pressure line to continuously monitor the transvalvular pressure gradient. It prevents bleeding at the puncture site during the intervention and presumably reduces the trauma to the artery. Because of its thrombogenic potential, heparinization of the patients is essential. The largest balloon accepted by the sheath is a 2 X 19 bifoil balloon which was the reason to use a bifoil balloon in some mitral valves. Trefoil balloons put in place through a long sheath provide some theoretical advantages over conventional single balloons introduced over guidewires that need to be evaluated by larger clinical studies. Although they do not prevent circulatory collapse during initial inflation in tight stenoses, they permit transvalvular flow when fully unfolded.