Elective EVAR Not as Successful in Women as in Men

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Women derive less benefit from elective endovascular aneurysm repair (EVAR) than men, showing higher rates of complications and 30-day mortality, according to a retrospective analysis published online February 10, 2012, ahead of print in the Journal of Vascular Surgery.

Researchers led by Manish Mehta, MD, MPH, of Albany Medical College (Albany, NY), looked at 2,631 endovascular and open surgical AAA repairs at their institution from 2002 to 2009. More than half of the procedures were EVAR (64.5%; n = 1,698) compared with open surgery (35.5%; n = 933). In particular, most were elective EVAR (60.5%; n = 1,592), with elective open surgery (29.9%; n = 788), emergent open surgery (5.5%; n = 145), and emergency EVAR (4%; n = 106) comprising the rest.

Of the elective EVAR procedures, over three-fourths were in men (78%; n = 1,248) and the remainder were in women (22%; n = 344).

During the procedure, women undergoing elective EVAR had more complications than men including arterial rupture (4.1% vs. 1.2%; P = 0.002), mean estimated blood loss (326.5 mL vs. 275 mL; P = 0.0381), and type 1 endoleak resulting in Palmaz stent placement at the aortic neck (16.1% vs. 8.0%; P = 0.0009).

Postoperative complications, 30-day mortality, and length of stay were also increased after elective EVAR in women compared with men (table 1).

Table 1. Postoperative Complications After Elective EVAR

 

After logistic regression analysis, female sex remained a significant risk factor for 30-day mortality in elective EVAR (OR 3.36; 95% CI 1.44-7.85; P = 0.01).

In each of the other groups (emergency EVAR, elective open repair, emergency open repair), 30-day mortality rates did not differ by sex, nor did intraprocedural and postoperative complications rates. Among women overall, there was no difference in mortality rates between EVAR and open surgery.

A Man’s Disease

According to Dr. Mehta, the findings came as a surprise. “There are some data out there that suggest that maybe EVAR does not benefit women as much as men,” he told TCTMD in a telephone interview. Even with this knowledge of the literature, “we thought that might not be the case because we were not consistently seeing bad complications and particularly because stent graft designs have improved over the years. So we thought we were doing better for women. What we learned, though, was quite the opposite.”

Dr. Mehta observed that the paper brings into focus the anatomical issues that differ in women vs. men. In addition, “[a]ortic aneurysm is still considered a man’s disease in many parts of the world, so what ends up happening is women are diagnosed later,” he said. “So the aneurysms tend to be larger and the aortic neck anatomy tends to be more hostile, which we clearly found.”

In the study, mean aneurysm size was roughly equivalent between men (5.63 cm) and women (5.55 cm; P = 0.1673). But given that women are smaller in terms of body size than men, Dr. Mehta noted, similar absolute aneurysm size actually translates to a relative increase in women.

Despite the results in elective EVAR, no gender differences in terms of complications and mortality were found in the other procedural groups. According to Dr. Mehta, the reason may be related to the planning that takes place in elective cases. “In planning, we are differentiating or selecting out women with more hostile anatomy, and we push the envelope in trying to fix them more so than in men because of the anatomical differences,” he said. “In emergent situations, we treat almost everybody the same way.”

No Gender Equality in Elective EVAR

Regardless, he added, when it comes to elective EVAR, the study points out very clearly that “men and women are not equal. The biggest point is that we need to continue the pursuit of better devices that are better suited to women.”

Dr. Mehta noted that for the past 5 to 7 years, there has been little evolution in device technology for EVAR, and that hopefully devices involving fenestrated stent graft technology will soon be available. The key for the next wave of devices will be the ability to navigate more difficult iliac arteries, preventing rupture, he said.

“If you’re a woman having elective EVAR, to have an odds ratio of 3.4 that you will die compared with a man indicates a serious problem with currently available stent grafts, and that’s the crux of this paper,” Dr. Mehta observed. “We need to continue to do a better job of innovation and making better devices that are more specific to the hostile anatomy that we tend to see more often in women.”

Endovascular Still Preferable to Surgery

But that does not mean the procedure should be discouraged in women, Dr. Mehta stressed, noting that “there’s no question if you compare elective EVAR to elective open surgery, the mortality and complication outcomes are much better with EVAR.”

Instead, clinicians need to “look at men and women differently when it comes to elective EVAR,” he said. “We need to recognize that there are some inherent risks with currently available stent grafts in women, and that these differences need to be understood and navigated. Maybe we can improve on some techniques that might decrease these complications.”

Study Details

Women undergoing elective EVAR were older than men (75.0 years vs. 73.3 years; P < 0.001) and had more COPD (23.8% vs. 16.9%; P < 0.005). Other risk factors such as mean AAA size, CAD, and hypertension were similar in both groups.

 

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Source:
Mehta M, Byrne WJ, Robinson H, et al. Women derive less benefit from elective endovascular aneurysm repair than men. J Vasc Surg. 2012;Epub ahead of print.

 

Disclosures:

• Dr. Mehta reports serving on the advisory board of Cordis and Trivascular, and as a speaker/consultant for Cordis, ev3 Endovascular, Medtronic, Trivascular, and WL Gore.

 

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