The porcine restenosis model using thermal balloon injury: comparison with the model by coronary stenting

Percutaneous coronary intervention (PCI) continues to revolutionize the treatment of coronary atherosclerosis and technologic advances require a preclinical coronary stenosis model. The purpose of this study was to systematically evaluate a porcine restenosis model of thermal balloon injury compared to stent overstretching.

To evaluate this injury model, 22 swine were utilized. For the induction of coronary stenoses, the thermal balloon-to-artery ratio was equal to the range of 1.2-1.3 and was placed at a desired location in the coronary arteries, inflated with 2 atm, and heated to 80 degrees C for 80 seconds. Quantitative coronary angiography was analyzed at baseline, immediately postprocedure, and 4 weeks at harvest. Quantitative coronary ultrasound analysis and histopathologic evaluation were also performed at 4 weeks postprocedure.

A total of 54 coronary arteries (thermal balloon injury [Thermo]; n = 43, coronary stenting [Stent]; n = 11) from a total of 18 animals were analyzed for this study. At 4 weeks postprocedure, significantly greater coronary stenoses were observed in the Thermo Group versus the Stent Group (minimum lumen diameter: 1.00 % 0.63 mm vs. 1.58 % 0.44 mm; p = 0.009, % diameter stenosis [DS]: 66.2 +/- 21.6% vs. 48.1 +/- 11.4%; p = 0.02). There were significant linear correlations between the balloon-to-artery ratio, post %DS and %DS at 4 weeks (balloon-to-artery ratio; r = 0.538; p = 0.0012, post %DS; r = -0.744; p < 0.0001, respectively).

This methodology may provide reproducible and consistent coronary stenoses. This model can be useful fnot only for the evaluation of medical devices, but also for technical training in PCI and development of coronary imaging technologies.