Delivery of endothelial cells to balloon-dilated rabbit arteries with use of a local delivery catheter

PURPOSE: Experiments were performed to determine if a local delivery cathet er could deliver endothelial cells that would be retained on the luminal su rface of balloon-dilated arteries. MATERIALS AND METHODS: Six New Zealand White rabbits underwent carotid cath eterization, arteriography, and balloon angioplasty of an external iliac ar tery. A local delivery catheter (Dispatch) was then positioned at the site of angioplasty and the 3-mm balloon was inflated. Cultured rabbit endotheli al cells (1.26 +/- 0.3 x 10(6)), previously stained with fluorescent dye PK H26, were delivered to the artery in three infusions separated by 10 minute s. The delivery balloon was deflated and removed 25 minutes after the last delivery. The arteries were then perfusion-fixed in situ at physiologic pre ssure, removed, and divided into four segments, and the segments were rapid ly frozen and cryosectioned. Eight sections from each arterial segment were examined by means of epifluorescence microscopy. The luminal surface of ea ch artery was visually divided into eight sectors of equal length and each sector was assigned a score based on the degree of endothelial coverage (0 = no coverage, 1 = < 50% coverage, 2 = > 50% coverage). RESULTS: The endothelial coverage score for the six arteries averaged 0.40 +/- 0.46 (SD; range, 0.04-1.24). Areas of each artery receiving scores of 0 , 1, and 2 averaged 68%, 25%, and 7%, respectively. Average coverage scores were 0.42, 0.38, 0.51, and 0.28 for individual segments along the length o f the artery. CONCLUSIONS: The Dispatch local delivery catheter is able to deliver endoth elial cells that adhere to balloon-dilated arteries. Although the magnitude of cellular retention was modest and varied among arteries, the retention along the length of each artery was constant.