Retractable-needle catheters: an update on local drug delivery in coronary interventions

In the treatment of coronary artery disease, local delivery of pharmaceutical substances has long been a goal, yet the technology is still evolving. Coronary stents have become the predominant means of treating obstructive lesions, and the need for additional pharmacologic treatment is evidenced by the popularity of drug-eluting stents. Moreover, stents have residual limitations, in particular in-stent thrombosis and late restenosis. Investigators have recently proposed delivering coronary drugs by means of local injection devices. These innovative devices, which incorporate retractable needles at the tip of a catheter, appear to be ready for clinical testing. In addition to solving many of the limitations of drug-eluting stents, local injection devices may eventually enable interventional cardiologists to treat vulnerable plaques. Herein, we review the evolution and current status of local drug delivery in the coronary arteries, with an emphasis on novel catheters that have retractable needles.