[Trefoil balloon, a new instrument for percutaneous valvuloplasty].

Complete obstruction of blood flow during balloon inflation is a major problem of percutaneous balloon valvuloplasty. To ensure continued transvalvular blood flow the authors have developed the "Trefoil balloon" consisting of three identical angioplasty balloons mounted on a single catheter. The Trefoil balloon was tested in the aorta and aortic valve in 4 dogs and produced a pressure gradient from 5 to 40 mm Hg where conventional balloons were completely occlusive. The Trefoil balloon was then used in 3 children with congenital valvular stenoses (2 pulmonary and 1 aortic stenosis). The immediate results of these valvuloplasties were satisfactory. Continued flow during balloon inflation was documented by right ventricular injection of contrast medium in the cases of pulmonary stenosis and by a systolic aortic pressure of 75 mm Hg during balloon inflation in the case of aortic stenosis. The Trefoil balloon is a promising new device for percutaneous valvuloplasty.