title: Natural history of atherosclerotic renal artery stenosis: a prospective study with duplex ultrasonography.
abstract: OBJECTIVE
  Although the prevalence of renal artery stenosis in patients with peripheral arterial disease is in the range of 30% to 40%, the role of renal revascularization in patients without severe hypertension or kidney failure is controversial. Duplex scanning is a noninvasive technique that is ideally suited for screening and follow-up of renal artery disease. The purpose of this study was to document the natural history of renal artery stenosis in patients who were not candidates for immediate renal revascularization.
  
  
  METHODS
  Eighty-four patients with at least one abnormal renal artery detected by duplex scanning were recruited from patients being screened for renal artery stenosis. Of the 168 renal artery/kidney sides, 29 were excluded (15 prior interventions, 6 nondiagnostic duplex scans, 8 presumed nonatherosclerotic lesions), leaving 80 patients with 139 sides for the follow-up protocol. Renal arteries were classified as normal, less than 60% stenosis, 60% or greater stenosis, or occluded by use of previously validated criteria.
  
  
  RESULTS
  The study group included 36 men and 44 women with a mean age of 66 years who were monitored for a mean interval of 12.7 months. The initial status of the 139 renal arteries was normal in 36, less than 60% stenosis in 35, 60% or greater stenosis in 63, and occluded in 5. Although none of the initially normal renal arteries showed disease progression, the cumulative incidence of progression from less than 60% to 60% or greater renal artery stenosis was 23% +/- 9% at 1 year and 42% +/- 14% at 2 years. All four renal arteries that progressed to occlusion had 60% or greater stenoses at the initial visit, and for those sides with a 60% or greater stenosis, the cumulative incidence of progression to occlusion was 5% +/- 3% at 1 year and 11% +/- 6% at 2 years. The mean decrease in kidney length associated with progression of renal artery stenosis to occlusion was 1.8 cm.
  
  
  CONCLUSIONS
  Progression of renal artery stenosis, as defined in this study, occurs at a rate of approximately 20% per year. Progression to occlusion is associated with a marked decrease in kidney length. Whether this natural history can be improved by earlier intervention for renal artery stenosis remains to be determined.
authors.affiliation: Department of Surgery, University of Washington, Seattle 98195.
authors.forename: R E
authors.initials: RE
authors.lastname: Zierler
authors.forename: R O
authors.initials: RO
authors.lastname: Bergelin
authors.forename: J A
authors.initials: JA
authors.lastname: Isaacson
authors.forename: D E
authors.initials: DE
authors.lastname: Strandness
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001161:Arteriosclerosis / Q000150:complications*; D005260:Female; D006801:Humans; D015994:Incidence; D015993:Life Tables; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012078:Renal Artery Obstruction / Q000145:classification / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D012720:Severity of Illness Index; D014463:Ultrasonography