A reliable porcine coronary model of chronic total occlusion using copper wire stents and bioabsorbable levo-polylactic acid polymer

Abstract

Background: Chronic total occlusion (CTO) remains a challenge in interventional cardiology. We investigated the feasibility and reliability of copper wire stents and levo-polylactic acid (L-PLA) as a means of CTO induction in a porcine model.

Methods and results: In one group of 20 swine, copper stems were crimped on a 3.0 mm angioplasty balloon and inserted into the mid-left anterior descending coronary artery (LAD). In the other group of 20 swine, L-PLA was wrapped on a guidewire and pushed into the distal LAD with a 3.0 mm balloon catheter to induce embolization. Of 20 swine which underwent copper stent implantation. 13 died of stent thrombosis. In the remaining 7 swine, total or near total occlusion with collateral circulation was observed at 5 weeks. Of 20 swine which underwent L-PLA embolization, 4 died of ventricular fibrillation during or shortly after the procedure. Serial histopathologic studies showed complete absorption of the polymer with replacement by fibrotic tissue approximately 4 weeks following the polymer implantation.

Conclusions: CTO could be reliably induced in porcine coronary arteries by copper stents and L-PLA. These models may support investigation of new percutaneous devices to facilitate CTO interventions.