Trefoil balloon for percutaneous valvuloplasty.

A new balloon (Trefoil balloon) was developed to avoid complete interruption of blood flow during percutaneous balloon valvuloplasty. It consists of three identical 2- to 4-cm-long angioplasty balloons mounted in a parallel fashion on a single catheter. Filled simultaneously, they assume the cross section of a rosette, allowing for continued blood flow. Trefoil balloons of various sizes were tested in five dogs (aorta and aortic valve). They created a gradient ranging from 5 to 40 mmHg where conventional, single balloons of comparable size were completely obstructive. In three consecutive patients with congenital pulmonary stenosis, Trefoil balloons were used successfully and without significant complications. Continued transvalvular blood flow during the actual dilatation process was documented in all cases. The Trefoil balloon is a promising new device for percutaneous valvuloplasty and, perhaps, coronary angioplasty.