Lorena Gonzalez1, Neal R. Barshes1, Richard L. Lu1, Kathryn Dougherty2, Zvonimir Krajcer2, Panos Kougias1
1Department of Vascular and Endovascular Surgery, Baylor College of Medicine, Houston, TX; 2Texas Heart Institute - St Luke's Episcopal Hospital, Houston, TX.
OBJECTIVES: It is unclear whether the type of proximal fixation and radial force associated with EVAR have any long-term impact on the aneurysm neck diameter (AND). We sought to identify whether AND changes occur and if any factors are associated with changes in AND.
METHODS: Post-EVAR computed tomography images were reviewed for all patients undergoing EVAR at two tertiary medical centers between November 2002 and March 2012 for whom >6 month post-EVAR imaging was obtained. The AND was defined as the minor axis 1cm inferior to the lowest renal artery. AND changes were calculated as the difference between pre-EVAR AND and AND at last follow-up scan. EVAR stent-graft type and other patient characteristics were obtained from chart review. Multivariable linear regression was used to identify factors independently associated with long-term AND changes.
RESULTS: A total of 151 patients meeting inclusion criteria underwent EVAR with one of five stent-graft types. The median age was 70 years old, and median follow-up time for these patients was 2.05 years. The mean initial AND was 24.5mm, and the median AND change was -0.2mm/yr. AND expansion >1mm/yr occurred in 27 patients (17.8%). Multivariable regression demonstrated that larger initial AND (p=0.001) and diabetes mellitus (p=0.03) were associated with reduced risk of AND expansion. The Zenith (p<0.001) and the Talent (p=0.07) stent-grafts were associated with increased risk of AND expansion compared to Excluder, AneuRx, and Powerlink devices. Overall, stent-grafts with suprarenal fixation were associated with increased rate of AND expansion compared to those that did not have suprarenal fixation (p=0.01).
CONCLUSIONS: Significant AND expansion after EVAR is uncommon. Necks that do expand only do so marginally but suprarenal fixation appears to be associated with an increased risk of long-term AND expansion. Future studies should address the incidence of AND during longer follow up and the relationship between AND expansion and secondary interventions after EVAR.
AUTHOR DISCLOSURES: N. R. Barshes: Nothing to disclose; K. Dougherty: Nothing to disclose; L. Gonzalez: Nothing to disclose; P. Kougias: Nothing to disclose; Z. Krajcer: Gore, Endologix, Medtronic, Consulting fees or other remuneration (payment); Gore, Endologix, Medtronic, Speaker’s bureau; R. L. Lu: Nothing to disclose.
Posted April 2013