Sex disparities in treatment and outcomes of abdominal aortic aneurysm

Last Updated: 2017-05-05

By Will Boggs MD

NEW YORK (Reuters Health) - Women face significant disparities in the treatment and outcomes of intact abdominal aortic aneurysm (AAA), according to a systematic review and meta-analysis.

"Just because in the past AAA has been a predominantly male disorder, we should not assume that parameters (including intra-operative fluids and post-operative care) and other care pathways which have been designed for men are the best care pathways for women,” Dr. Janet T. Powell from Imperial College London told Reuters Health by email. “We need sex-specific care pathways, including endograft design.”

Women with AAA are often considered for repair at diameters smaller than the 5.5 cm recommended for men, because their rate of rupture of small AAA is four times higher than that of men at the same diameter. Endovascular aneurysm repair (EVAR) has been shown to be superior to open repair, but women were poorly represented in those studies.

Dr. Powell and colleagues in Screening Women for Aortic aNeurysm (SWAN) undertook a systematic review and meta-analysis aimed at quantifying how the prognosis of women with AAA compares with that of men.

Meta-analysis of five studies with information on 1,507 men and 400 women yielded an overall pooled estimate of suitability for EVAR of 34% in women and 54% in men, a significant difference.

In four retrospective studies, 34% of potentially eligible women were either not offered or refused AAA repair, about twice the nonintervention rate in men (19%), the researchers report in The Lancet, online April 25.

Data from nine studies including more than 11,000 women operated on yielded an overall 30-day mortality of 2.31% after EVAR and 5.37% after open repair, compared to 1.37% after EVAR and 2.82% after open repair among more than 52,000 men operated on in these same studies.

After adjustments, 30-day mortality was significantly higher in women than in men after EVAR (odds ratio, 1.67) and open repair (OR, 1.76).

“Women have smaller aortas than men, and perhaps if a smaller threshold for both diagnosis and intervention were introduced, compared with those recommended for men, women might have a better chance of being offered and surviving intervention at a younger age,” the researchers conclude.

“Given the relatively high mortality following open abdominal aortic aneurysm repair in women, it would seem to be crucial either to design an endograft for women or to accept that most women need to be referred to centers that either offer endovascular sealing technology or are specialists in open repair. Such measures might see an improved prognosis for women,” they add.

“Both sex-specific reporting and sex-specific care pathways are important, even in the older population,” Dr. Powell said.

Dr. Minna Johansson from the University of Gothenburg, Sweden, who co-authored a linked editorial, told Reuters Health by email, "There are major ethical dilemmas within this field, which are often not given adequate attention. The importance of respect for the autonomy of the individual patient cannot be overstressed. In research of this field, we have a tendency to focus on mortality outcomes, while many other measures are vital for the individual to make an informed decision. For example; what proportion are able to return to an independent life after surgery? We need to involve patients in future research, to ascertain that patient relevant outcomes are taken into account.”

“There are no clear answers, especially regarding cut-off for diagnosis and surgery in women,” she said. “I would suggest a careful approach. It is important not to get carried away by the apparent inequity in care between men and women. Intuitively, it might seem that we need to be more active in women. But, by being more active, we could actually do more harm than good. We must give equal consideration to harms and benefits by different approaches.”

“The evidence base for the management of AAA in women is very poor,” Dr. Johansson concluded. “This study doesn't provide clear answers on how we should handle this clinically. I think the suggestion made by the authors to centralize surgery for women with intact AAA is sensible. But in general, we need better evidence before we know how to best handle AAA in women.”

SOURCE: http://bit.ly/2pgdWrd and http://bit.ly/2qL8wVu

Lancet 2017.