Effects of renal volume and single-kidney glomerular filtration rate on renal functional outcome in atherosclerotic renal artery stenosis.
BACKGROUND
Renal functional outcome is unpredictable after revascularization of high-grade atherosclerotic renal artery stenosis (RAS). 'Hibernating' parenchyma describes acute parenchymal injury where renal dysfunction is potentially reversible with treatment of the stenosis. We analysed renal parenchymal volume (PV) and single-kidney glomerular filtration rate (SK-GFR) characteristics to identify kidneys with hibernating parenchyma and hence determine renal functional outcome after revascularization.


METHODS
Fifty patients with > or =50% RAS underwent baseline analyses: (i) PV using magnetic resonance imaging; (ii) radioisotopic SK-GFR. Twenty-one patients (27 kidneys) underwent renal revascularization and 29 medical therapy alone.


RESULTS
Patients with revascularized kidneys manifesting high PV:SK-GFR showed improvement in global estimated GFR compared to conservatively managed counterparts at 6 months and 1 year (6 months: 6.2 +/- 2.9 versus -3.7 +/- 6.8, P = 0.038; 1 year: 3.5 +/- 3.0 versus -5.1 +/- 5.1 ml/min/1.73 m(2), P = 0.021). Twelve revascularized patients (16 kidneys) underwent repeat SK-GFR 4 months post-revascularization. Six of 16 revascularized kidneys had high baseline PV:SK-GFR and showed improved SK-GFR compared to kidneys with low or normal PV:SK-GFR (6.3 +/- 2.0 versus -0.9 +/- 4.2 ml/min, P = 0.002).


CONCLUSIONS
Our data suggest that, after revascularization, GFR improvement is likely if there is a disproportionately higher baseline PV:SK-GFR in the RAS kidney. Analysing these parameters can potentially identify these 'hibernating' kidneys and aid determination of renal functional outcome in RAS.
Cheung
Ching M
CM
Department of Renal Medicine and Radiology, Salford Royal Hospital, Stott Lane, Salford M6 8HD, UK. mmmr4cmc@doctors.org.uk
Chrysochou
Constantina
C
Shurrab
Ala'a E
AE
Buckley
David L
DL
Cowie
Alistair
A
Kalra
Philip A
PA
D000368:Aged; D000800:Angioplasty, Balloon; D050197:Atherosclerosis / Q000503:physiopathology* / Q000628:therapy; D001794:Blood Pressure; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D012078:Renal Artery Obstruction / Q000503:physiopathology* / Q000628:therapy; D016896:Treatment Outcome