Objectives: We describe a new angioplasty device (Infiltrator Angioplasty Balloon Catheter; IABC) with intramural drug delivery capability. The conventional balloon part of the device, when inflated, dilates the vessel or has three rows of longitudinally mounted infiltrator nipples to penetrate the tunica media. Through an independent infiltrator port and nipples, drugs can be infiltrated directly into the vessel wall.
Methods: The device was tested in 117 normal coronary arteries of 58 farm pigs.
Results: (1) The infiltration procedure does not damage the vessel angiographically or histologically. At the infiltration site, the endothelial layer and the internal elastic lamina has a controlled interruption, and the infiltrated fluid is distributed among the medial layers, causing a mild focal edema and medial thickening (1.8 times on average). (2) Rhodamine tracer is circularly and evenly distributed through the whole width of the vessel wall within 10 min after infiltration. (3) Two weeks after the infiltration procedure, the medial layer reveals mild local thickening and remodelling without luminal narrowing. (4) Of the intramurally infiltrated Tcm99-labeled surfurcolloid, 83.8% is detectable at 5 min after the delivery procedure by gamma camera. (5) The IABC, if oversized, is able to achieve angiographic dilatation in normal pig coronary arteries, causing histologic damage similar to or less than that induced by conventional balloon dilatation.
Conclusions: The IABC can deliver fluid-phase substances directly into the vessel wall with microliter accuracy and with 90% efficiency without significant acute and subacute damage to the vessel wall. It is also suitable for combined dilatation and local drug delivery.