Anatomical differences could make aneurysm repair more difficult in women

February 4, 2008

Endovascular aneurysm repair to treat abdominal aortic aneurysm tends to be more challenging in women than in men due to anatomical differences, according to a study presented at the International Symposium on Endovascular Therapy held last month in Florida.

Endovascular aneurysm repair to treat abdominal aortic aneurysm tends to be more challenging in women than in men due to anatomical differences, according to a study presented at the International Symposium on Endovascular Therapy held last month in Florida.

Abdominal arteries and the proximal landing zones used to anchor intravascular stents for AAA repair tend to be smaller in female patients, said Dr. Mei Nortley, a vascular surgeon and research fellow at St. Mary's Hospital in London. The study of 35 women and 150 men found that the blood vessels used to access the aorta had a mean measurement of 7.4 mm in women, compared with 9.1 mm in men. In many cases, EVAR devices may be too large to easily pass through the smaller artery.

Calcification and clotting at the top of the aneurysm occurred in 34% of women versus 19% of men, and the neck of the aneurysm was more severely angled in women with mild to moderate hypertension. Women had a 50° angle on average, while men had a 35° angle on average.

The study confirms what many interventionalists have seen clinically and also highlights some of the lesser known difficulties of the procedure in women.

"Most of us understand that women have smaller arteries," said Dr. Barry Katzen, founder and director of the Baptist Cardiac and Vascular Institute in Miami. "But the fact that in this large group of patients, women also had problems with their landing zones - that was something new."

But Nortley cautions that the new data should not be used to rule out EVAR in women.

"Women do appear to have features that may make them technically more challenging, but EVAR is certainly not contraindicated in women," she said. "The advantages of EVAR are proven and should be offered to women. We hope the data will encourage all parties to consider the potential pitfalls in women and overcome them creatively."

Some manufacturers are already trying to address the difficulties by providing smaller delivery systems, Katzen said. While most current devices require delivery apparatus that are at least 18 French in diameter, his practice is participating in research trials for devices that can be placed through 16-F sheathes.

Until smaller devices and delivery systems are available, Katzen said his practice sometimes uses a hybrid approach to stent placement.

"We'll do everything we can to avoid open surgery. Sometimes, it involves a hybrid procedure or modification of access, where we open up the incision and go into a larger artery than the one in the groin," he said.

Katzen cautions that even this approach essentially extends the level of invasiveness, making it less ideal than a strictly endovascular approach. He is hopeful that Nortley's study will provide extra impetus to manufacturers to create smaller devices and delivery systems.

"This really adds to the body of evidence. Hopefully, we'll be able to come up with devices that will be able to treat women better. The great thing about doing that is it will help us treat men better also, because whatever advantages they bring by reducing size will be carried over to the whole patient population," he said.

For more information from the Diagnostic Imaging archives:

Advances solve problems in imaging patients with AAA stents

Endovascular aortic aneurysm repair provides appropriate treatment for high-risk patients

3D ultrasound speeds up monitoring of abdominal aortic aneurysms

Two-phase angiography of aneurysm repair reduces dose, maintains integrity