title: Postconditioning in major vascular surgery: prevention of renal failure.
abstract: BACKGROUND
  Postconditioning is a novel reperfusion technique to reduce ischemia-reperfusion injuries. The aim of the study was to investigate this method in an animal model of lower limb revascularization for purpose of preventing postoperative renal failure.
  
  
  METHODS
  Bilateral lower limb ischemia was induced in male Wistar rats for 3 hours by infrarenal aorta clamping under narcosis. Revascularization was allowed by declamping the aorta. Postconditioning (additional 10 sec reocclusion, 10 sec reperfusion in 6 cycles) was induced at the onset of revascularization. Myocyte injury and renal function changes were assessed 4, 24 and 72 hours postoperatively. Hemodynamic monitoring was performed by invasive arterial blood pressure registering and a kidney surface laser Doppler flowmeter.
  
  
  RESULTS
  Muscle viability studies showed no significant improvement with the use of postconditioning in terms of ischemic rhabdomyolysis (4 h: ischemia-reperfusion (IR) group: 42.93 ± 19.20% vs. postconditioned (PostC) group: 43.27 ± 27.13%). At the same time, renal functional laboratory tests and kidney myoglobin immunohistochemistry demonstrated significantly less expressed kidney injury in postconditioned animals (renal failure index: 4 h: IR: 2.37 ± 1.43 mM vs. PostC: 0.92 ± 0.32 mM; 24 h: IR: 1.53 ± 0.45 mM vs. PostC: 0.77 ± 0.34 mM; 72 h: IR: 1.51 ± 0.36 mM vs. PostC: 0.43 ± 0.28 mM), while systemic hemodynamics and kidney microcirculation significantly improved (calculated reperfusion area: IR: 82.31 ± 12.23% vs. PostC: 99.01 ± 2.76%), and arterial blood gas analysis showed a lesser extent systemic acidic load after revascularization (a defined relative base excess parameter: 1(st) s: IR: 2.25 ± 1.14 vs. PostC: 1.80 ± 0.66; 2(nd) s: IR: 2.14 ± 1.44 vs. PostC: 2.44 ± 1.14, 3(rd) s: IR: 3.99 ± 3.09 vs. PostC: 2.07 ± 0.82; 4(th) s: IR: 3.28 ± 0.32 vs. PostC: 2.05 ± 0.56).
  
  
  CONCLUSIONS
  The results suggest a protective role for postconditioning in major vascular surgeries against renal complications through a possible alternative release of nephrotoxic agents and exerting a positive effect on hemodynamic stability.
authors.affiliation: 1st Department of Surgery, Semmelweis University, Budapest, Hungary. aranyi.p@gmail.com.
authors.forename: Peter
authors.initials: P
authors.lastname: Aranyi
authors.affiliation: 1st Department of Surgery, Semmelweis University, Budapest, Hungary. zsturoczi@gmail.com.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Turoczi
authors.affiliation: 1st Department of Surgery, Semmelweis University, Budapest, Hungary. garbaiszdavid@t-online.hu.
authors.forename: David
authors.initials: D
authors.lastname: Garbaisz
authors.affiliation: 2nd Department of Pathology, Semmelweis University, Budapest, Hungary. lotz.gabor@med.semmelweis-univ.hu.
authors.forename: Gabor
authors.initials: G
authors.lastname: Lotz
authors.affiliation: Eötvös Loránd University, Faculty of Science, Institute of Mathematics, Budapest, Hungary. janos@geleji.hu.
authors.forename: Janos
authors.initials: J
authors.lastname: Geleji
authors.affiliation: 1st Department of Surgery, Semmelweis University, Budapest, Hungary. viktolhegedus@gmail.com.
authors.forename: Viktor
authors.initials: V
authors.lastname: Hegedus
authors.affiliation: First Department of Internal Medicine, University of Szeged, Szeged, Hungary. zrakonczay@gmail.com.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Rakonczay
authors.affiliation: First Department of Internal Medicine, University of Szeged, Szeged, Hungary. ballatanar@gmail.com.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Balla
authors.affiliation: 1st Department of Surgery, Semmelweis University, Budapest, Hungary. harsanyi.laszlo@med.semmelweis-univ.hu.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Harsanyi
authors.affiliation: 1st Department of Surgery, Semmelweis University, Budapest, Hungary. szijartoattila@gmail.com.
authors.forename: Attila
authors.initials: A
authors.lastname: Szijarto
mesh_terms: D000818:Animals; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism; D006439:Hemodynamics; D007150:Immunohistochemistry; D057775:Ischemic Postconditioning; D007672:Kidney Cortex / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D007677:Kidney Function Tests; D017078:Laser-Doppler Flowmetry; D015227:Lipid Peroxidation; D035002:Lower Extremity / Q000098:blood supply / Q000503:physiopathology; D008297:Male; D008833:Microcirculation; D009132:Muscles / Q000473:pathology; D009211:Myoglobin / Q000378:metabolism; D017208:Rats, Wistar; D051437:Renal Insufficiency / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control*; D015427:Reperfusion Injury / Q000517:prevention & control; D014656:Vascular Surgical Procedures / Q000009:adverse effects*
chemical_list: D050884:HSP72 Heat-Shock Proteins; D009211:Myoglobin