The Influence of Gender and Aortic Aneurysm Size on Eligibility for Endovascular Abdominal Aortic Aneurysm Repair
Does gender influence eligibility for “on-label” endovascular abdominal aortic aneurysm (AAA) repair?
Between July 1996 and December 2009, 1,063 computed tomgraphy (CT) scans with 3D reconstructions from a single institution were analyzed. All aneurysms were infrarenal, unrepaired, and either >5 cm or the aneurysm sac diameter was greater than twice the aortic diameter at the renal level. Trained personnel, blinded to proposed treatment, evaluated each CT for a prespecified set of 23 anatomic measurements. AAAs were evaluated for common Instructions for Use (IFU) criterion: infrarenal neck diameter of 18-32 mm, infrarenal neck length of 15 mm, neck angulation <60°, and iliac access lumen of at least 6 mm.
Neck length, diameter, and angulation differ in women compared to men (p < 0.001). This persisted even after adjusting for age and size of the AAA. Infrarenal aortic neck length <15 mm was found in 47% of men and 63% of women. Neck angulation <60° was more prominent in men than women (12% vs. 26%) and minimum iliac diameter of 6 mm was noted in only 35% of men versus 55% of women. Only 32% of men and 12% women had all three neck criteria and had iliac lumen diameter >6 mm. Eligibility for “on-label” endovascular aneurysm repair (EVAR) by neck criterion does not decline significantly until AAA size exceeds 5.5 cm in women and 6.5 cm in men. Older patient age, increasing aneurysm diameter, and female gender were independently associated with decreased odds of meeting all device IFU neck criteria.
Women are significantly less likely to meet device IFU criterion for EVAR. Devices that accommodate shorter infrarenal necks will have the greatest impact for expanding on-label EVAR. Observation of small AAAs until they reach the standard diameter threshold for repair will not compromise EVAR eligibility.
As endograft delivery devices become lower profile and devices are designed to accommodate shorter infrarenal necks, the number of women who can be treated by ‘on-label’ EVAR will undoubtedly increase. What is interesting to me, however, is that the authors found that only 32% of men and 12% of women met all IFU criteria for on-label EVAR. Since nearly 70% of all AAAs are currently repaired with EVAR, it appears that a significant number of EVARs, possibly even the majority of EVARs in women, are being done ‘off-label.’ It would be interesting to know exactly what percentage of women currently get ‘off-label’ EVARs, and how these EVARs perform in the intermediate- and long-term.
Keywords: Esophageal Achalasia, Blood Vessel Prosthesis Implantation, Perioperative Care, Cardiovascular Diseases, Aortic Aneurysm, Abdominal, Vascular Surgical Procedures
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