EFFICACY OF LOW-MOLECULAR-WEIGHT HEPARIN DELIVERY WITH THE DISPATCH CATHETER FOLLOWING BALLOON ANGIOPLASTY IN THE RABBIT ILIAC ARTERY

Local drug delivery can be achieved with active injection systems or p assive contact of a compound with the arterial wall. The Dispatch(R) c atheter allows for passive diffusion of drugs from drug compartments w hile preserving blood flow through the central conduit. The aim of thi s study was to investigate whether a reduction in neointima formation can be achieved by local delivery of a limited amount of a highly conc entrated solution of the low-molecular-weight heparin Reviparin. In 16 New Zealand white rabbits, successful balloon dilatation was performe d in both iliac arteries, followed by local delivery of 4 mi Reviparin (1,000 IU/ml), The arteries were harvested at 7, 28, or 56 d followin g the procedure, The intimal cell layers increased substantially betwe en 7 and 28 d following balloon dilatation with or without local drug delivery, The medial cell layers showed only a little increase. Prolif eration of smooth muscle cells reached an early peak after 7 d, with a significantly higher proliferation index following local delivery, Th e maximum amount of macrophages in the intima and media was detected a fter 28 d. The lumen area decreased with time and was 0.6 +/- 0.7 mm(2 ) in the local delivery group at 56 d compared with 0.5 +/- 0.5 mm(2) in the control group. In conclusion, local delivery of Reviparin with the Dispatch catheter is safe and feasible, However, the infusion of h ighly concentrated low-molecular-weight heparin over a short period of time did not result in a reduction of neointima formation and resteno sis following balloon dilatation in the rabbit iliac artery, (C) 1997 Wiley-Liss, Inc.