Ask the Experts - Endovascular Repair Vs Conventional Open Surgery for...
What are the indications for and outcomes of endovascular repair vs conventional open surgical repair in the treatment of nonruptured abdominal aortic aneurysms?

Dr. P. Starusta

Abdominal aortic aneurysms (AAA) can be identified prerupture by physical exam or by ultrasound. At present, most surgeons would recommend conventional open surgical repair for good-surgical-risk patients with AAA greater than 5 cm in diameter. Endovascular stent graft repair is recommended for elderly AAA patients with significant medical comorbidities but with suitable anatomy for stent placement.

At this point, the availability of endovascular systems is not considered to have altered the indications for recommending conventional open surgical repair for preruptured AAA, because endovascular repair has not yet convincingly been proven to reliably prevent rupture over long-term follow-up. Long-term follow-up data and randomized, prospective clinical trials of endovascular repair compared with conventional open repair are still needed. Furthermore, in March 2001, Guidant Corporation (Indianapolis, Indiana) voluntarily halted production and sales of its ANCURE system for treating abdominal aortic aneurysms. The company said it had identified certain deficiencies in its regulatory processes and communications with the FDA.

The goal of AAA repair is to prevent aneurysm rupture, and this has been achieved with AAA stent-graft devices in 3- to 5-year follow-up studies. Rupture rates of less than 2% after endovascular exclusion have been reported, which is comparable to rates achieved with interventional surgical AAA repair. Endograft AAA repair has a greater than 90% incidence of aneurysm exclusion at 1 month. Operative 1-month mortality has been similar in multicenter prospective clinical trials (stent-graft 2%, open 3%).

The durability of the endovascular AAA repair procedure is still under study. The late surgical conversion is less than 7% at 3 years after stent-graft deployment. The EuroStar registry (a multicenter experience of 35 European and Middle Eastern countries) suggests that up to one third of patients may require secondary procedures to maintain device patency or to treat endoleak. This incidence of secondary interventions is higher than after conventional surgical repair.

Because of issues regarding the importance of endoleaks, the risk of AAA rupture, and stent-graft device durability, vigilant follow-up of patients receiving endovascular grafts is necessary. In general, patient follow-up with CT scans and radiographs of the abdomen are required every 6-12 months after stent-graft AAA repair, with more frequent surveillance if an endoleak is present. Expansion of AAA diameter during surveillance requires surgical conversion.