title: Hemodynamic determinants of perivascular collateral development in swine renal artery stenosis.
abstract: BACKGROUND
  Renal artery stenosis (RAS) resulting in reduced renal blood flow (RBF) is a common cause of secondary hypertension and deterioration of renal function, which may lead to end-stage renal disease. Recruitment and formation of periarterial collateral vessels may serve to bypass RAS and restore distal blood supply. We hypothesized that development of collaterals around RAS may preserve kidney function.
  
  
  METHODS
  Collateral formation index (CI) was assessed using multidetector computed tomography as fractional vascular volume surrounding the stenosis in 31 pigs with unilateral RAS. Single kidney RBF and glomerular filtration rate (GFR) were also measured.
  
  
  RESULTS
  Of 25 pigs that developed significant stenosis (≥65%), 8 demonstrated minor collateral development (CI < 0.3), and 17 showed major collateral development (CI ≥ 0.3). The degree of RAS was significantly higher in pigs with major collaterals compared with pigs with minor collaterals, and poststenotic kidney cortical volume, perfusion, RBF, and GFR were significantly lower. In a subset of pigs matched for the degree of RAS, RBF and GFR remained lower in pigs with major collaterals.
  
  
  CONCLUSIONS
  We conclude that collaterals develop in animals with significant RAS in proportion to its severity and might be triggered by distal injury, such as decreases in cortical volume and perfusion. However, development of collaterals was unable to confer measurable benefits for stenotic kidney function distal to severe RAS.
authors: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors: James D
authors: JD
authors: Krier
authors: John A
authors: JA
authors: Crane
authors: Alfonso
authors: A
authors: Eirin
authors: Xiang-Yang
authors: XY
authors: Zhu
authors: Amir
authors: A
authors: Lerman
authors: Lilach O
authors: LO
authors: Lerman
mesh_terms: D000818:Animals; D003097:Collateral Circulation / Q000502:physiology*; D004195:Disease Models, Animal; D005919:Glomerular Filtration Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D007668:Kidney / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D061330:Multidetector Computed Tomography; D012039:Regional Blood Flow / Q000502:physiology; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013552:Swine
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