Restenosis following coronary angioplasty represents a major clinical problem. Irreversible electroporation (IRE) is a nonthermal, nonpharmacological cell ablation method. IRE utilizes a sequence of electrical pulses that produce permanent damage to tissue within a few seconds. METHODS AND RESULTS: The left carotid arteries of eight rats underwent in vivo intimal damage using two Fogarty angioplasty catheters. The procedure was immediately followed by IRE ablation in four rats, while the remaining four were used as the control group. The IRE ablation was performed using a sequence of ten dc pulses of 3800 V/cm, 100 micros each, at a frequency of ten pulses per second, applied across the blood vessel between two parallel electrodes. The electrical conductance of the treated tissue was measured during the electroporation to provide real-time feedback of the process. Left carotid arteries were excised and fixated after a 28-day follow-up period. Neointimal formation was evaluated histologically. The use of IRE was successful in three out of four animals in a way that is consistent with the measurements of blood vessel electrical properties. The integrity of the endothelial layer was recovered in the IRE-treated animals, compared with control. Successful IRE reduced neointima to media ratio (0.57 +/-0.4 versus 1.88 +/-1.0, P = 0.02). CONCLUSIONS: We report for the first time the in vivo results of attenuation of neointimal formation using IRE. Our study shows that IRE might be able to attenuate neointimal formation after angioplasty damage in a rodent model of restenosis. This approach may open new venues in the treatment of coronary artery restenosis after balloon angioplasty.