Minimally invasive endovascular repair of abdominal aortic aneurysm can be
safely performed with low reintervention rates, comparable to open surgical
repair, according to a large study presented here at the Society of
Interventional Radiology 34th Annual Scientific Meeting.

In the study, prospective data were collected on a group of 453 patients who
underwent endograft repair during an 8-year period (April 2000 through January
2008). The investigators analyzed the data for associated morbidity and the rate
of secondary interventions, and they looked at whether the need for
reintervention could be predicted by routine surveillance computed tomography
(CT). If the need existed, intense surveillance with CT was continued.

Goal Is to Prevent Rupture

If an aneurysm ruptures, there is severe pain, and the grim death rate is around
80%, and 59% to 83% will die before reaching the hospital, and for patients who
reach the hospital, postsurgery, 40% will die," coauthor and presenter Tarun
Sabharwal, MD, FSIR, FCIRSE, interventional radiologist at Guy's and St. Thomas'
Hospital in London, United Kingdom, said during a news conference. "The goal of
the interventional radiologist is to prevent aneurysms from rupturing."

Of the 453 patients in the group whose aneurysms were found on screening tests,
406 patients (89.8%) opted for elective repair; 17 (3.6%) presented as urgent
cases, and 30 (6.6%) showed up as true-rupture emergency cases. The
male-to-female ratio was 11:1, with a median age of 76 years (age range, 40 ¡V
93 years).

The overall 30-day mortality rate was 3.3% (15 of 453 patients) for the
minimally invasive procedure. The historic mortality rate for elective open
surgical repair of nonruptured abdominal aortic aneurysm is 5%, according to
researchers.

Overall, reintervention was needed in 7.2% (33 of 453 patients) and, of this
group, only 1.3% (6 of 453 patients) were detected during routine CT
surveillance.

Of the reinterventions needed, endoleaks that required reintervention were seen
in 13 (2.8%) of 453 patients (10 were type I and 3 were type III). Limb
occlusion that required an extra-anatomical bypass was performed in 15 (3.3%) of
453 patients, and amputations were necessary in 2 patients. Finally, graft
explantation after infection was performed in 2 patients.

Disproved Myths

"Endovascular repair has had a mixed reception because of the rate of secondary
reinterventions, complication rates, and the long-term surveillance required
with risk of radiation cancers, but we have disproved the myths about the
durability and effectiveness of minimally invasive endovascular aneurysm
repair," said Dr. Sabharwal.

"Our results in following patients over the last 8 years contradict reports of
high rates of secondary interventions coupled with the need for prolonged
CT-scan surveillance," he said. "Recovery time is measured in days to weeks, as
opposed to surgery patients who take several weeks to months to recover; some
patients [who undergo the minimally invasive procedure] are discharged the day
after treatment."

Dr. Sabharwal concluded that endoluminal repair of infrarenal aortic aneurysms
can be performed with low reintervention rates. "The lower rates are due to
newer-generation stent grafts and we have learned to modify technique," he said.

He added that the value of prolonged surveillance of frequent CT imaging with
accompanying radiation risks appears to be limited because few complications are
detected during routine CT surveillance. "We would advocate a revision of
current surveillance protocols," he said.

Session moderator Robert L. Vogelzang, MD, interventional radiologist and
professor of radiology at Northwestern Memorial Hospital and Northwestern
University Feinberg School of Medicine, in Chicago, Illinois, told Medscape
Radiology that "this study indicates to me some hugely important results that
are long term, and their work approach is for durability and permanence of their
surgical repair technique ¡X and that's a good thing. It's a big step forward."

The study did not receive commercial support. Dr. Sabharwal and Dr. Vogelzang
have disclosed no relevant financial relationships.

Society of Interventional Radiology (SIR) 34th Annual Scientific Meeting:
Abstract 211. Presented March 11, 2009.