Effect of blood flow on drug release from DES: An experimental study

DES has made stenting a successful treatment modality. Still problems exists such as late thrombosis and continued neo-intimal proliferation. Blood flow affects the drug retained in the stent and subsequently on the time frame of vascular healing. To find out drug release kinetics from DES implanted in two different flow conditions, DES were implanted in porcine carotid artery and coronary artery. The drug release kinetics was found out by estimating the drug retained in the stent at different time periods. Through this study it is shown that DES in the coronary artery has a T1/2 of 24 days compared to 2 days in the carotid artery. The difference in T1/2 is attributed to the difference in flow as estimated using Hagen - Poiseuille equation. Evaluation of DES through heterotopic implantation may yield false results due to flow discrepancy. Moreover flow conditions should also be considered while designing the drug matrix to have optimum clinical efficacy. (C) 2007 Elsevier Ireland Ltd. All rights reserved.