title: Gradient changes in porcine renal arterial vascular anatomy and blood flow after cryoablation.
abstract: OBJECTIVE
  We quantified temporal changes in vascular structure and blood flow after cryosurgery of the porcine kidney in vivo.
  
  
  METHODS
  We studied 5 groups of 4 kidneys each with a survival time of 20 minutes, 4 hours, 2 days, and 1 and 2 weeks after cryoablation, respectively. Before harvesting the kidneys, fluorescently labeled microspheres were administrated in the descending aorta. After harvest the kidney and its vasculature were casted with fluorescently dyed elastomer, frozen and processed in an imaging cryomicrotome to reveal the 3-dimensional arterial branching structure and microsphere distribution. In regions of interest vessels were segmented by image analysis software and histograms were constructed to reveal the total summed vessel length as a function of diameter. A characteristic diameter of the ablated area was measured.
  
  
  RESULTS
  The 20-minute survival group histograms showed a significant shift of the peak to larger diameters (p<0.002), indicating that smaller vessels were destroyed. Microsphere density was decreased to 2% in the ablated region but not in the nonablated border zone, depending on the remaining crater crossing larger vessels. After 2 weeks neither vessels nor microspheres were left in the ablated area, which had shrunk by about 40% in diameter. Study limitations are the lack of histological confirmation and the use of normal rather than cancerous tissue.
  
  
  CONCLUSIONS
  Larger vessels remain patent just after ablation and transport blood to the border of the ablation crater but perfusion within the crater is halted instantly. Characteristic crater diameter increases initially but decreases thereafter. Destruction of vessels and tissue is complete 2 weeks after cryoablation.
authors.affiliation: Department of Urology, St. Lucas Andreas Hospital and Onze Lieve Vrouwe Gasthuis, Academic Medical Centre, University of Amsterdam, The Netherlands.
authors.forename: Brunolf W
authors.initials: BW
authors.lastname: Lagerveld
authors.forename: Pepijn
authors.initials: P
authors.lastname: van Horssen
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Laguna
authors.forename: Jeroen P H M
authors.initials: JP
authors.lastname: van den Wijngaard
authors.forename: Maria
authors.initials: M
authors.lastname: Siebes
authors.forename: Hessel
authors.initials: H
authors.lastname: Wijkstra
authors.forename: Jean J M C H
authors.initials: JJ
authors.lastname: de la Rosette
authors.forename: Jos A E
authors.initials: JA
authors.lastname: Spaan
mesh_terms: D000818:Animals; D003452:Cryosurgery; D007668:Kidney / Q000098:blood supply* / Q000601:surgery*; D012039:Regional Blood Flow; D012077:Renal Artery / Q000033:anatomy & histology* / Q000502:physiology*; D013552:Swine