Secondary Intervention After Endovascular Abdominal Aortic Aneurysm Repair

Abstract

Conclusion: Secondary interventions are common after endovascular aneurysm repair but do not adversely affect aneurysm related death or overall actuarial 5-year survival. Summary: A substantial number of secondary interventions are performed in patients who have undergone endovascular aneurysm repair (EVAR). Rates of secondary intervention range from 10% to 18%, with most problems addressed with endovascular procedures. The authors sought to determine the indications for secondary interventions after EVAR in their institution and the effect of these interventions on long-term survival. From January 1997 to December 2007, 832 patients underwent EVAR. All grafts placed in this study were Food and Drug Administration approved and included the Cook Zenith graft, Gore Excluder, Medtronic AneuRx graft, and the Endologix Powerlink graft. Grafts were placed by vascular surgeons in the operating room using fixed imaging assistance. (The article did not specify who performed catheter-based secondary interventions.) Patients undergoing secondary interventions were stratified according to indications and the specific nature of the secondary intervention and treatment. Study end points were aneurysm-related and overall survival, and freedom from secondary intervention. At a mean follow-up of 35 months, 91 patients (11%) underwent 131 secondary interventions. There were no demographic features that predicted the need for a secondary intervention. The 5-year survival from secondary interventions was 80%, and 76% of the secondary interventions were accomplished with a catheter-based approach. Secondary interventions were successful >80% of the time for all indications except type II endoleak, where the initial secondary intervention was successful only 34% of the time. Multivariate analysis predicting secondary interventions identified aneurysm sac size >5.5 cm (odds ratio, 2.1; P = .004) and preprocedure coil embolization of hypogastric or inferior mesenteric artery (odds ratio, 2.1; P = .008) as predictors of secondary interventions. The 5-year actuarial survival was 70% and aneurysm-related survival was 97.5%. There was no survival difference in patients who underwent secondary interventions compared with those who did not. Comment: This is a large series of EVARs from an institution known for excellence in treatment of aneurysm disease. The authors report a rate of secondary interventions is in the low range of those previously reported. There is no obvious explanation for this in the data presented. Clearly, secondary interventions after EVAR are at the discretion of the attending surgeon, and some centers will have a more conservative approach than others. It is interesting to note that an aneurysm >5.5 cm was associated with an increased need for secondary interventions. A cynic might point out that secondary interventions are more common when EVAR was actually indicated in the first place! The article would have been strengthened by more details regarding patient follow-up. We do not know how many of the patients in this series were followed per protocol, how many computed tomography scans were performed per patient, or how many patients were lost to follow-up. It perhaps would have been preferable to report the rate of intervention as a function of patient-years of follow-up. Overall, the data again suggest the safety of EVAR and its effectiveness in preventing aneurysm-related death. Rates of secondary intervention seem reasonable from what we have come to expect. The rate of secondary interventions in any series will depend on the completeness of follow-up of the patients, per protocol follow-up of patients, the number of patient-years of follow-up, and individual surgeon threshold for performing secondary interventions.