title: Longitudinal changes in kidney parenchymal volume associated with renal artery stenting.
abstract: OBJECTIVE
  This study assessed the longitudinal changes in renal volume after renal artery stenting (RAS) to determine if renal mass is preserved by stenting.
  
  
  METHODS
  The study cohort consisted of 38 patients with longitudinal imaging available for renal volume quantification before and after RAS. Renal volume was estimated as (kidney length) × (width) × (depth/2) based on preoperative renal imaging. For each patient, the clinical response of blood pressure (BP) and renal function to RAS was categorized according to modified American Heart Association guidelines. Changes in renal volume were assessed using paired nonparametric analyses.
  
  
  RESULTS
  The cohort was a median age of 69 years (interquartile range [IQR], 60-74 years). A favorable BP response was observed in 11 of 38 patients (28.9%). At a median interval between imaging studies of 21 months (IQR, 13-32 months), ipsilateral renal volume was significantly increased from baseline (146.8 vs 133.8 cm(3);P = .02). This represents a 6.9% relative increase in ipsilateral kidney volume from baseline. A significant negative correlation between preoperative renal volume and the relative change in renal volume postoperatively (r = -0.42; P = .0055) suggests that smaller kidneys experienced the greatest gains in renal volume after stenting. It is noteworthy that the 25 patients with no change in BP or renal function-clinical failures using traditional definitions-experienced a 12% relative increase in ipsilateral renal volume after RAS. Multivariate analysis determined that stable or improved renal volume after stenting was an independent predictor of stable or improved long-term renal function (odds ratio, 0.008; 95% confidence interval, 0.000-0.206; P = .004).
  
  
  CONCLUSIONS
  These data lend credence to the belief that RAS preserves renal mass in some patients. This benefit of RAS even extends to those patients who would be considered treatment failures by traditional definitions. Patients with stable or increased renal volume after RAS had more stable renal function during long-term follow-up, whereas patients with renal volume loss after stenting were prone to deterioration of renal function.
authors.affiliation: Dallas Veterans Affairs Medical Center, Dallas, TX, USA.
authors.forename: J Gregory
authors.initials: JG
authors.lastname: Modrall
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Timaran
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rosero
authors.forename: Jayer
authors.initials: J
authors.lastname: Chung
authors.forename: Mitchell
authors.initials: M
authors.lastname: Plummer
authors.forename: R James
authors.initials: RJ
authors.lastname: Valentine
authors.forename: Clayton
authors.initials: C
authors.lastname: Trimmer
mesh_terms: D000368:Aged; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation*; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011237:Predictive Value of Tests; D012078:Renal Artery Obstruction / Q000175:diagnosis / Q000628:therapy*; D017582:Renal Replacement Therapy; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015607:Stents; D013781:Texas; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D003404:Creatinine