Barriers to Endovascular Aortic Aneurysm Repair: Past Experience and Implications for Future Device Development

Abstract

Despite improvements in endovascular aortic aneurysm repair (EVAR) devices and techniques, significant anatomic constraints still preclude successful EVAR in a large number of patients. The authors sought to identify the current barriers to EVAR and examine their evolution over time. Patients were evaluated for potential endovascular repair by computed tomography angiography (CTA) with or without supplemental conventional arteriograms. The patient population was separated into 2 groups (A and B) based on early and late time periods in the experience with EVAR, corresponding to the availability of various devices. Group A (early) consisted of the Guidant Ancure, Medtronic Talent, and AneuRx devices and comprised patients presenting between April 1997 through June 2000. Group B (late) consisted of the Medtronic AneuRx, Cook Zenith, Edwards Lifepath, Gore Excluder, and Endologix PowerLink devices and comprised patients presenting between July 2000 and December 2003. Patient demographics and anatomic reasons for rejection were recorded in a database for statistical analysis. In total, 547 patients were evaluated (463 men, 84 women). Of these, 346 patients (63%; 312 men, 34 women) were deemed suitable candidates for EVAR and 201 (37%; 151 men, 50 women) were rejected. There was no significant difference in the overall rate of rejection in the early vs the late time period (34% A, 41% B, p= 0.08), but the number of exclusion criteria per patient decreased over time; patients rejected for EVAR had an overall average of 1.6 exclusion criteria (Group A, 1.9; Group B, 1.2). The reasons for rejection did significantly change over time. Specifically, rejection on the basis of inadequate arterial access, presence of extensive iliac artery aneurysms, or an inadequate proximal neck decreased. A disproportionate number of women were excluded throughout the study: Group A, 56% of women compared to 30% of men (p= 0.0003); Group B, 63% of women compared to 36% of men (p= 0.0022). Women were more likely than men to have inadequate arterial access routes. In addition, patients with high operative risk were also more likely to be excluded from EVAR, a finding that persisted over time. Anatomic constraints continue to pose significant challenges to aortic endografting. Progress has been made in that technological advances have conquered some of the previous anatomic challenges, chiefly those of arterial access and treatment of concomitant iliac aneurysm disease. However, the overall rate of rejection for EVAR remains the same. The chief anatomic barriers continue to be the difficult aortic neck and management of branched vascular segments.

Get full access to this article

View all access options for this article.

References

Parodi JC , Palmaz JC , Barone HD : Transfemoral intraluminal graft implantation for abdominal aortic aneurysms. Ann Vasc Surg 5:491-499, 1991.

Carpenter JP , Baum RA , Barker CF , et al : Impact of exclusion criteria on patient selection for endovascular abdominal aortic aneurysm repair. J Vasc Surg 34:1050-1054, 2001.

Arko FR , Konstantinos AF , Seidel SA , et al : How many patients with infrarenal aneurysm are candidates for endovascular repair? The Northern California experience. J Endovasc Ther 11:33-40, 2004.

Wolf YG , Fogarty TJ , Olcott C IV , et al : Endovascular repair of abdominal aortic aneurysms: Eligibility rate and impact on the rate of open repair. J Vasc Surg 32:519-523, 2000.

Carpenter JP , Fairman RM , Barker CF , et al : Endovascular AAA repair in patients with renal insufficiency: Strategies for reducing adverse renal events. Cardiovasc Surg 9:559-564, 2001.

Mehta M , Veith FJ , Lipsitz EC , et al : Is elevated creatinine level a contraindication to endovascular aneurysm repair? J Vasc Surg 39:118-123, 2004.

Jordan WD , Alcocer F , Wirthlin DJ , et al : Abdominal aortic aneurysms in “high-risk” surgical patients. Ann Surg 5:623-630, 2003.

Henretta JP , Karch LA , Hodgson KJ , et al : Special iliac artery considerations during aneurysm endo-grafting. Am J Surg 178:212-218, 1999.

Lee WA , Berceli SA , Huber TS , et al : Morbidity with retroperitoneal procedures during endovascular abdominal aortic aneurysm repair. J Vasc Surg 38:459-463, 2003.

10.

Criado FJ , Wilson EP , Abul-Khoudoud O , et al : Brachial artery catheterization to facilitate endovascular grafting of AAA: Safety and rationale. J Vasc Surg 32:1137-1141, 2000.

11.

Kritpracha B , Pigott JP , Russell TE , et al : Bell-bottom aortoiliac endografts: An alternative that preserves pelvic blood flow. J Vasc Surg 35:874-881, 2002.

12.

Gitlitz DB , Ramaswami G , Kaplan D , et al : Endovascular stent grafting in the presence of aortic neck filling defects: Early clinical experience. J Vasc Surg 33:340-344, 2001.

13.

Morrissey NJ , Faries PL , Teodorescu V , et al : Trans-renal bare stents in endovascular treatment of abdominal aortic aneurysms. J Invas Cardiol 14:36-40, 2002.

14.

Hosokawa H , Iwase T , Sato M , et al : Successful endovascular repair of juxtarenal and suprarenal aortic aneurysms with a branched stent graft. J Vasc Surg 33:11087-11092, 2001.

15.

Velazquez OC , Larson RA , Baum RA , et al : Gender-related differences in infrarenal aortic aneurysm morphologic features: Issues relevant to Ancure and Talent endografts. J Vasc Surg S33:77-84, 2001.