Efficacy of the Wolverine cutting balloon on a circumferential calcified coronary lesion: Bench test using a three-dimensional printer and computer simulation with the finite element method.

Heavy calcification is one of the factors that hinder the success of coronary angioplasty, and a cutting balloon is used for such lesions. This study aimed to explore the optimal method of dilation of highly calcified lesions using a cutting balloon. Calcification models were developed from patient computed tomography and intravascular ultrasound data, and were constructed using three-dimensional printers. The lesions were dilated using a Wolverine™ cutting balloon and NC Emerge™ noncompliant balloon catheter, and the success rate of dilation and maximum dilation pressure were compared. The maximum first principal stresses in calcified lesions were also evaluated by computer simulation using the finite element method. In the bench test, the dilation success rate of the Wolverine™ cutting balloon was higher and the maximum dilation pressure required was lower (p < 0.01 in all analyses), compared with that of the NC Emerge™ balloon catheter. Finite element analysis showed that the cutting blade increased the maximum first principal stresses in calcified lesions, thus allowing for successful dilation at low pressures. The highest stress was obtained when the cutting blade was positioned at the thinnest part of the calcification. The cutting balloon allows for efficient calcification expansion by concentrating the stresses in the blade. When a cutting balloon is used, if the calcified lesion cannot be expanded in a single dilation, dilation success may be achieved after the balloon is rotated and the position of the blade is changed.