Standard and New Treatments for Abdominal Aortic Aneurysms

The Value of the Montefiore Endovascular Grafts for Difficult Aneurysms

Abstract

The mortality rate following rupture of an abdominal aortic aneurysm (AAA) is 80-90% and the main goal of treatment is to prevent rupture. Treatment of the aneurysm is generally recommended for patients with an aneurysm larger than 5 cm in diameter, and the only effective treatment has been to replace the aneurysm with a prosthetic graft. Traditionally, this is performed through a major laparotomy; that is, open surgical repair, which itself carries a mortality rate of 4-8% and requires a hospital stay of 7-10 days. In addition, some sick patients are deemed a prohibitive risk for such major surgery and, therefore, treatment may be deferred. Endovascular grafts (EVGs) that enable treatment of patients with AAA without the need for laparotomy were developed in the hope of improving on the shortcomings of the standard repair technique. In addition to the various industry-made EVGs the authors have been using a surgeon-made Montefiore Endovascular Grafting System (MEGS). The recent introduction of several industry-made devices has prompted some to postulate that MEGS is no longer required. The 60 patients with AAA treated from 1 July 1997 to 30 June 1998 were evaluated for the inclusion criteria for industry-made EVG protocols. Those excluded from these protocols were evaluated for the MEGS. Open surgical repair was reserved for those unsuitable for any EVG repair or those not consenting to EVG repair. Thirty-seven percent of all cases could be treated with an industry-made device. By using the MEGS, an additional 43% of the cases could be treated endovascularly. In total, 80% of AAAs were able to be treated endovascularly. The reasons for excluding patients from industry-made devices were a combination of the following factors: (1) Short (<1.5 cm) or angulated (>60) proximal necks, (2) iliac artery aneurysms, (3) small, diseased or tortuous access arteries, and (4) small distal aortas. The mean length of stay for those treated endovascularly was 2.3 days, whereas it was 9 days for those treated by open surgery. There was no difference in the morbidity and mortality rates. EVG repair is feasible and safe for the majority of patients with AAAs; however, long-term durability is yet to be shown. Despite the availability of industry-made devices, there appears to be a continuing role for MEGS, especially for difficult aneurysms including those patients with complex anatomy and those with ruptured AAAs. (Jpn Circ J 1999; 63: 829 - 837)