title: Role of type II endoleak in sac regression after endovascular repair of infrarenal abdominal aortic aneurysms.
abstract: OBJECTIVE
  Endovascular repair (EVAR) of infrarenal aortic aneurysms (AAA) is increasingly used in patients with suitable aortic morphology conforming to device-specific instructions for use. Despite improvements in graft design, type II endoleak (EL-2) from the inferior mesenteric artery (EL-IMA) or the lumbar artery (EL-LA) remains the Achilles' heel of EVAR. The objective of this study was to evaluate the natural history of the AAA sac after EVAR. We hypothesized that persistent EL-2 would be associated with inferior AAA sac volume regression.
  
  
  METHODS
  A retrospective analysis was performed on all nonruptured AAA treated by elective EVAR using Food and Drug Administration-approved endografts from January 2005 to December 2008 in our facility. Review of medical records and preoperative and follow-up computed tomography angiograms at 1, 6, and 12 months was performed. Patients with type I, III, and IV endoleaks were excluded, as were those lost to all follow-up. AAA size and volume were analyzed using TeraRecon software (Aquarius Intuition, Foster City, Calif). Change in AAA sac volume was compared in patients with and without EL-2, and with an occluded vs patent IMA.
  
  
  RESULTS
  The study cohort comprised 191 patients (161 men, 30 women) with a mean age of 74 years. The mean preoperative AAA diameter was 5.5 cm (range, 4-11 cm), and mean volume was 137.45 cm(3). EL-2 was present in 24% at completion of EVAR and in 9% at a mean follow-up of 6 months (range 4-8 months). Completion angiography at 1 month showed 63% of EL-2 had resolved. Those with EL-2 present at 1 month had statistically inferior sac regression compared with those who did not (23% reduction vs 2% increase at 1 year; P = .002). Preoperatively, the IMA was occluded by coils or was chronically occluded in 82 patients vs 109 patients who had a patent IMA. At the 6-month follow-up, patients with an occluded IMA had an EL-2 rate of 2.4% vs 14.7% in those with a patent IMA (P = .005 by t-test). Sac volume regression was 21.8% in those with an occluded IMA vs 13.2% in those with a patent IMA (P = .004 by t-test). Regression in AAA sac volume was highly significant in patients with occluded IMA, at 30% vs 16% at 1 year (P = .0018 by two-sided t-test).
  
  
  CONCLUSIONS
  The presence of persistent EL-2 after EVAR results in inferior AAA sac regression. A preoperatively patent IMA is associated with increased rates of EL-2 and inferior AAA sac regression. Consideration should be given to preoperative occlusion of a patent IMA before EVAR.
authors.affiliation: Department of Surgery, Mercy Medical Center and Iowa Heart Center, Des Moines, Iowa.
authors.forename: Jared
authors.initials: J
authors.lastname: Kray
authors.affiliation: Department of Surgery, Mercy Medical Center and Iowa Heart Center, Des Moines, Iowa.
authors.forename: Spencer
authors.initials: S
authors.lastname: Kirk
authors.affiliation: Department of Surgery, Mercy Medical Center and Iowa Heart Center, Des Moines, Iowa.
authors.forename: Jan
authors.initials: J
authors.lastname: Franko
authors.affiliation: Department of Surgery, Mercy Medical Center and Iowa Heart Center, Des Moines, Iowa. Electronic address: dchew@iowaheart.com.
authors.forename: David K
authors.initials: DK
authors.lastname: Chew
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D001027:Aortography / Q000379:methods; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation; D004621:Embolization, Therapeutic; D057867:Endoleak / Q000175:diagnosis / Q000209:etiology*; D057510:Endovascular Procedures / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D017537:Mesenteric Artery, Inferior / Q000503:physiopathology; D008875:Middle Aged; D012189:Retrospective Studies; D015607:Stents; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014654:Vascular Patency