Local Drug Delivery Device Research Articles

Efficiency Study of the Annular Balloon Catheter a New Local Drug Delivery Device

Efficiency Study of the Annular Balloon Catheter a New Local Drug Delivery Device

Sustained local drug delivery from a radiopaque implanted reservoir.

A new polymeric biomaterial that contains covalently bound iodine, and is therefore radiopaque, was used to construct a sustained local drug-delivery device. A polymeric wall was designed to be porous (i.e., passage of low-molecular-weight molecules across the wall is possible), self-healing, and biocompatible. Once implanted, the sphere cavity can be filled and refilled with a concentrated solution of a (cytostatic) drug, which is subsequently released by slow diffusion into the tissue region surrounding the sphere. This principle of sustained local drug delivery is shown by a series of in vitro experiments on the release of 5-fluorouracil, and in vivo animal experiments, using x-ray fluoroscopic and scintigraphic techniques.

1001-26 Local Dissolution of Intracoronary Thrombus with Urokinase Using the Dispatch™ Catheter: Clinical Studies

The Dispatch™ Catheter is a new local drug delivery device which allows for the prolonged infusion of therapeutic agents at an angioplasty site while still maintaining distal coronary perfusion. To determine the efficacy of this device in dissolving intraluminal clot with local urokinase infusion, 29 patients with thrombus-containing stenoses were treated with the Dispatch™ catheter either prior to (n = 16) or following (n = 13) coronary angioplasty or directional atherectomy. The study group consisted of 15 males and 14 females with a mean age of 58.1 years. Clinical diagnoses included unstable angina (n = 14), acute myocardial infarction (n = 11) or post infarction angina (n = 4). Urokinase was infused at either 10,000 unitlcc (n = 22) or 30,000 units/cc (n = 7) at 0.5 cc/min for up to 30 minutes. All coronary angiograms were analyzed to determine Thrombus Score (0 – 3), TIMI flow, and quantitative coronary measurements pre and post Dispatch™ therapy. (Thrombus Score: 0 = no thrombus, 1 = possible thrombus, 2 = definite thrombus < 3 mm, 3 = definite thrombus > 3 mm). Infusions of urokinase for 30 mins were well tolerated in 25 patients without adverse clinical, hemodynamic or electrical sequelae. In the remaining 4 patients, limited infusions were tolerated only for 2.5, 5, 6 and 11 mins because of chest pain with EKG changes secondary either to sidebranch occlusion or inadequete distal perfusion. For the entire study group, Thrombus Score decreased from 2.0 ± 0.7 to 0.5 ± 0.8, TIMI Flow increased from 2.1 ± 1.3 to 3.0 ± 0.0, and minimal lumen diameter increased from 0.70 ± 0.59 to 1.58 ± 0.51 mm (all p < 0.01). Distal embolization, no-reflow, and abrupt closure were not observed in any patient. Reduction of thrombus-containing stenoses and dissolution of intracoronary thrombus can be rapidly achieved in patients with infusions of limited quantities of urokinase with the Dispatch™ catheter. Sidebranch occlusion and inability to dilate coronary stenoses with inadequate distal perfusion may limit the duration of drug infusion with this device.

Methods and devices for local drug delivery in coronary and peripheral arteries

New developments in catheter design, molecular biology, and polymer chemistry have made it possible to deliver pharmaceutical agents and genetic material directly into the arterial wall to modulate the response to injury. Several local drug delivery catheters of various designs in addition to biodegradable and coated stents are currently being evaluated as devices to facilitate local delivery of agents into the arterial wall. Approaches to locally sustained delivery include the controlled release of medications, the affinity-based delivery of medications administered systemically but accumulated locally, and gene therapy.