An in vitro model for vascular smooth muscle trauma due to angioplasty

Percutaneous Transluminal Coronary Angioplasty (PTCA) has proven to be beneficial to patients in danger of death from myocardial infarction. The major limitation with this modern success in conquering coronary (or any other vessel) obstruction is the phenomenon of restenosis. The pathology underlying restenosis differs substantially from the pathology of the disease leading to the obstruction of the blood vessel, namely, atherosclerosis. PTCA mitigates the consequences of an old disease, atherosclerosis, while at the same time elicits a new pathology, restenosis. The purpose of this study was to determine the mechanical loading conditions that VSM cells can withstand without leading to restenosis. We have designed a device for applying a uniform and isotropic 2-D strain to a flexible cell culture membrane. This device allows precise control of the applied strain and strain rate and quantification of cell responses in terms of cell membrane damage. The determination of the threshold criteria for VSM cell injury has important implications for the possible modification and/or automation of the PTCA technique in order to minimize VSM injury and avoid restenosis.