Abdominal aortic aneurysms (AAA) affect approximately two percent of women and five percent of men over age sixty five, and are almost certainly fatal if allowed to rupture. Although surgery involving vascular grafts or endovascular graft systems is widely accepted as a standard treatment for AAA, new, minimally invasive stent grafting technologies are rapidly entering the market. Stented aneurysms are, however, like stented postangioplasty arteries, subject to thrombolysis and restenosis. Heparin and Heparin derivatives are commonly used to treat thrombolysis; several pharmacotherapeutic agents are claimed to control restenosis. Implant Sciences proposes to improve drug delivery to AAA sites by incorporating Heparin and a restenosis-inhibiting drug into a non-erodable, biodurable-polyurethane graft-coating. Rapamycin, based on its success in recently completed and highly publicized clinical trials when delivered from an eluting stent directly to percutaneous coronary revascularization sites, is the inhibitor of choice. To sequester the drugs, an eluting polymer currently marketed in Europe as VascuLink will be employed. By substituting for systemic drug administration localized, time-release, multi-drug delivery via a coated-stent, the proposed device not only affects a lifesaving repair but also, by minimizing Heparin and Rapamycin doses, reduces the potential for adverse side effects.
Although endovascular repair of AAA is not likely to replace surery, it can be extended to many patients who were previously considered poor surgical candidates. Compared to open surgery the hospital stay and the recovery times are shorter, both perceived positively by the patient (improved quality of life) and by the healthcare system (cost effectiveness). With the population aging and approximately 100,000 new AAA cases diagnosed every year, the commercial potential is significant, and, with the newer, improved devices, will become even more so.
