title: Effect of suprarenal versus infrarenal aortic endograft fixation on renal function and renal artery patency: a comparative study with intermediate follow-up.
abstract: OBJECTIVE
  Suprarenal fixation of aortic endografts appears to be a safe option in patients with a short or conical proximal aortic neck. However, concern persists regarding the long-term effect on renal function when renal artery ostia are crossed by the uncovered stent. We investigated the effect of suprarenal versus infrarenal endograft fixation on renal function and renal artery patency after endovascular aortic aneurysm repair.
  
  
  METHODS
  Records of 91 patients who underwent endovascular aortic aneurysm repair with a modular bifurcated stent graft between November 1999 and January 2002 were reviewed retrospectively. Two patients receiving dialysis because of chronic renal failure were excluded. Infrarenal fixation was used in 57 patients (group 1), and suprarenal fixation was used in 32 patients (group 2). In two patients in group 1 a Gianturco Z stent was inserted transrenally because of intraoperative proximal type I endoleak, and data for these patients were excluded from analysis. Follow-up evaluation was performed at 1, 6, and 12 months, and yearly thereafter, and included clinical assessment, measurement of serum creatinine concentration (SCr), and computed tomography angiography, per standard protocol. Median follow-up was 12 months (range, 1-36 months).
  
  
  RESULTS
  There was no statistically significant difference in patient demographic data, aneurysm size, or preoperative risk factors. Median SCr was significantly higher in group 2 (suprarenal fixation) than in group 1 (infrarenal fixation) preoperatively (1.2 mg/dL [range, 0.6-2.3 mg/dL] vs 0.9 mg/dL [range, 0.6-1.9 mg/dL], P =.008) and at 1 month postoperatively (1.1 mg/dL [range, 0.8-5.6 mg/dL] vs 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.045). There was a significant increase in median SCr in both groups at 1 month postoperatively (group 1, 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.05; group 2, 1.1 mg/dL [range, 0.8-5.6 mg/dL] [mean SCr, 1.35 mg/dL vs 1.15 mg/dL, respectively], P <.05). In group 1 SCr was increased significantly at 6 and 12 months (P <.001), whereas in group 2 SCr also increased at 6 and 12 months, but not significantly. The change in SCr over time was not significantly different between the two groups. In two of 32 patients in group 2, renal artery occlusion developed, associated with perfusion defects in renal parenchyma and persistently elevated SCr. Analysis of renal artery patency did not demonstrate any association between patency and treatment. No patient developed hypertension during follow-up.
  
  
  CONCLUSIONS
  Suprarenal endograft fixation does not lead to significant renal dysfunction, and renal artery occlusion is uncommon within 12 months. A larger study with longer follow-up is essential to determine overall effects on renal function and renal artery patency.
authors.affiliation: Section of Vascular Surgery, Department of General Surgery, Mayo Clinic Jacksonville, 4500 San Pablo Rd, Jacksonville, FL 32224, USA. louislau@doctors.org.uk
authors.forename: L Louis
authors.initials: LL
authors.lastname: Lau
authors.forename: Albert G
authors.initials: AG
authors.lastname: Hakaim
authors.forename: W Andrew
authors.initials: WA
authors.lastname: Oldenburg
authors.forename: Beate
authors.initials: B
authors.lastname: Neuhauser
authors.forename: J Mark
authors.initials: JM
authors.lastname: McKinney
authors.forename: Ricardo
authors.initials: R
authors.lastname: Paz-Fumagalli
authors.forename: Andrew
authors.initials: A
authors.lastname: Stockland
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007674:Kidney Diseases / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology*; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014654:Vascular Patency / Q000502:physiology*