An algorithmic approach to balloon undilatable coronary lesions.

Balloon undilatable lesions are lesions that have been successfully crossed by both a guidewire and a balloon but cannot be expanded despite multiple high-pressure balloon inflations. Balloon undilatable lesions can be de novo or in-stent. We describe a systematic, algorithmic approach to treat both de novo and in-stent balloon undilatable lesions using various techniques, such as high-pressure balloon inflation, plaque modification balloons, intravascular lithotripsy, very high-pressure balloon inflation, coronary atherectomy, laser coronary angioplasty, and extraplaque lesion crossing. Knowledge of the various techniques can increase the efficiency, success and safety of the procedure.