title: Is neck dilatation after endovascular aneurysm repair graft dependent? Results of 4 US Phase II trials.
abstract: Long-term success of endovascular aneurysm repair (EVAR) relies on a stable proximal neck. The authors' goal was to determine whether neck dilatation after EVAR varies among 4 different endografts and whether it is related to complications of the proximal neck. Core laboratory data from 4 phase II trials of aortic endografts were analyzed for neck diameter changes over time. Patients who had at least 24 months' follow-up were included in the analysis. Neck measurement methodology varied among the 3 core labs used. Values are reported within the parameters used by each lab. Short-axis neck diameter close to 5 mm below the renal arteries, when available, was used for longitudinal comparisons. Dilation was defined as an enlargement of 3 mm or more from the first postoperative scan to the last available follow-up for each patient. Graft migration and late proximal endoleaks were determined by the individual core labs. A limited number of Lifepath grafts had most recent follow-up measurements performed by the authors. Results were compared by using Student's t test, chi-square analysis, and the Pearson correlation coefficient. Postoperative measurements from 729 EVAR patients were examined. Follow-up ranged from 24 to 60 months for 229 Ancure (Guidant) and 258 AneuRx (Medtronic) patients, and from 24 to 36 months for 211 Excluder (Gore) and 31 first-generation Lifepath (Edwards) patients. Neck dilation was noted in 124 patients (17.0%) and did not differ significantly among graft types. The incidences of late proximal endoleaks were similar among graft types, but rates of migration differed (p=0.01). Dilation was associated with migration in Ancure (p=0.03) and Excluder (p=0.02) grafts. Late proximal endoleaks were seen in 4.1% of patients with and in 0.7% of patients without dilation (p=0.001). Patients with initial neck diameter >25 mm had significantly less dilatation than those with smaller necks (p<0.001). The incidence of neck dilation approached 20% in all EVAR patients after 24 months and was not significantly different among graft types. Neck dilation of 3 mm or more appears to be one risk factor for migration and late proximal endoleak.
authors.affiliation: Division of Vascular Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Ellen D
authors.initials: ED
authors.lastname: Dillavou
authors.forename: Satish
authors.initials: S
authors.lastname: Muluk
authors.forename: Michel S
authors.initials: MS
authors.lastname: Makaroun
mesh_terms: D017544:Aortic Aneurysm, Abdominal / Q000503:physiopathology / Q000601:surgery*; D001807:Blood Vessel Prosthesis / Q000009:adverse effects*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D017322:Clinical Trials, Phase II as Topic; D004108:Dilatation, Pathologic / Q000453:epidemiology; D018450:Disease Progression; D005548:Foreign-Body Migration / Q000209:etiology; D006801:Humans; D015994:Incidence; D011475:Prosthesis Failure; D014652:Vascular Diseases / Q000209:etiology