title: Anatomic characteristics and natural history of renal artery aneurysms during longitudinal imaging surveillance.
abstract: OBJECTIVE
  Renal artery aneurysms (RAAs) are uncommon, and rates of growth and rupture are unknown. Limited evidence therefore exists to guide clinical management of RAAs, particularly small aneurysms that are asymptomatic. To further characterize the natural history of RAAs, we studied anatomic characteristics and changes in diameter during imaging surveillance.
  
  
  METHODS
  Patients evaluated for native RAAs at a single institution during a 5-year period (July 2008 to July 2013) were identified and analyzed retrospectively. Patients with two or more cross-sectional imaging studies (computed tomography or magnetic resonance imaging) more than 1 month apart were included. Demographic and clinical data were collected from medical records, and anatomic data (including aneurysm diameter, calcification, and location) were obtained from electronic images. Changes in RAA diameters over time were evaluated by plots and Wilcoxon signed rank tests.
  
  
  RESULTS
  Sixty-eight RAAs in 55 patients were analyzed. Median follow-up was 19.4 months (interquartile range, 11.2-49.0 months). Mean age at presentation was 61.8 ± 9.8 years, and 73% of patients were women. Hypertension was prevalent among 73% of patients. Multiple RAAs were present in 18% of patients, and 24% also had arterial aneurysms of other splanchnic or iliac vessels. The majority of RAAs were calcified and located at the main renal artery bifurcation. Mean initial aneurysm diameter was 16.0 ± 6.4 mm. Median annualized growth rate was 0.06 mm (interquartile range, -0.07 to 0.33 mm; P = .11). No RAA ruptures or acute symptoms occurred during surveillance, and 10.3% of RAAs were repaired electively.
  
  
  CONCLUSIONS
  Risk of short-term RAA growth or rupture was low. These findings suggest that annual (or less frequent) imaging surveillance is safe in the majority of patients and do not support pre-emptive repair of asymptomatic, small-diameter RAAs.
authors.affiliation: Department of Vascular and Endovascular Surgery, Wake Forest University School of Medicine, Winston-Salem, NC.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Wayne
authors.affiliation: Department of Vascular and Endovascular Surgery, Wake Forest University School of Medicine, Winston-Salem, NC.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Edwards
authors.affiliation: Department of Biostatistical Sciences, Wake Forest University School of Medicine, Winston-Salem, NC.
authors.forename: Jeanette M
authors.initials: JM
authors.lastname: Stafford
authors.affiliation: Department of Vascular and Endovascular Surgery, Wake Forest University School of Medicine, Winston-Salem, NC.
authors.forename: Kimberley J
authors.initials: KJ
authors.lastname: Hansen
authors.affiliation: Department of Vascular and Endovascular Surgery, Wake Forest University School of Medicine, Winston-Salem, NC. Electronic address: macorrie@wakehealth.edu.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Corriere
mesh_terms: D000368:Aged; D000783:Aneurysm / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D058070:Asymptomatic Diseases; D003952:Diagnostic Imaging / Q000379:methods; D018450:Disease Progression; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009657:North Carolina / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D061205:Vascular Calcification / Q000175:diagnosis