title: Spinal cord ischemia after selective cerebral perfusion in a porcine "frozen elephant trunk" simulation model.
abstract: BACKGROUND
  The "frozen elephant trunk" procedure (FET) represents the therapy of choice for extended aortic diseases. The aim of our study was to analyze whether 90 minutes of selective cerebral perfusion (SCP) at 28 °C followed by permanent occlusion of the thoracic segmental arteries (TSA) would cause spinal cord ischemia in a porcine model.
  
  
  METHODS
  14 pigs (41 ± 3 kg) were cooled on CPB to 28 °C. After aortic clamping, SCP was established for 90 minutes. Randomly, in 7 animals the TSA were clipped (T4-T13); the TSA of 7 animals remained untouched. After the animals were weaned from CPB, hemodynamic data were registered for 120 minutes. Regional spinal cord blood flow (SCBF) was calculated, and motor-evoked potentials (MEP) were assessed at 6 time points. After sacrifice of the animals, the spinal cord was analyzed histologically by use of a schematic grading system (0 = normal; 8 = total necrosis).
  
  
  RESULTS
  During SCP the SCBF was maintained at baseline (5.9 ± 2.4 mL/min/100 g) in the T4-T13 region but showed a decrease (from 8.4 ± 4.3 to 1.3 ± 1.5 mL/min/100 g) in the L1-L5 region. During reperfusion it increased, with two to three times higher values in the nonclipped animals. After 90 minutes of SCP, the MEP reached lower levels in the L1-L5 region of the TSA-clipped animals: 59% ± 7% vs 84 ± 15% (vastus medialis muscle) and 48% ± 6% vs 82% ± 26% (tibialis anterior muscle). The MEP recovered only in the nonclipped group. Higher ischemia rates were seen in the L1-L5 region of the TSA-clipped animals (score: 6.0 ± 0.6 vs 2.5 ± 2.3).
  
  
  CONCLUSIONS
  90 minutes of SCP provided sufficient spinal cord protection during arch replacement at 28 °C. In combination with permanent TSA occlusion, the lumbar spinal cord perfusion may be altered, which causes functional and structural damage.
authors.affiliation: Department for Cardiothoracic Surgery, BG University Hospital Bergmannsheil, Ruhr-University of Bochum, Bochum, Germany. Electronic address: peter.haldenwang@bergmannsheil.de.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Haldenwang
authors.affiliation: Department of Neuroanatomy and Molecular Brain Research, Ruhr-University of Bochum, Bochum, Germany.
authors.forename: Nora
authors.initials: N
authors.lastname: Prochnow
authors.affiliation: Department of Anesthesiology, Intensive Care, Palliative Care and Pain Medicine, Ruhr-University of Bochum, Bochum, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Baumann
authors.affiliation: Department for Cardiothoracic Surgery, BG University Hospital Bergmannsheil, Ruhr-University of Bochum, Bochum, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Buchwald
authors.affiliation: Department for Cardiothoracic Surgery, BG University Hospital Bergmannsheil, Ruhr-University of Bochum, Bochum, Germany.
authors.forename: Lorine
authors.initials: L
authors.lastname: Häuser
authors.affiliation: Department for Cardiothoracic Surgery, BG University Hospital Bergmannsheil, Ruhr-University of Bochum, Bochum, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Schlömicher
authors.affiliation: Department of Neuroanatomy and Molecular Brain Research, Ruhr-University of Bochum, Bochum, Germany.
authors.forename: Damian
authors.initials: D
authors.lastname: Ziebura
authors.affiliation: Institute for Pathology, Ruhr-University of Bochum BG University Hospital Bergmannsheil, Ruhr-University of Bochum, Bochum, Germany.
authors.forename: Inge
authors.initials: I
authors.lastname: Schmitz
authors.affiliation: Institute for Medical Statistics, Informatics and Epidemiology, University of Cologne, Cologne, Germany.
authors.forename: Hildegard
authors.initials: H
authors.lastname: Christ
authors.affiliation: Department for Cardiothoracic Surgery, BG University Hospital Bergmannsheil, Ruhr-University of Bochum, Bochum, Germany.
authors.forename: Justus T
authors.initials: JT
authors.lastname: Strauch
mesh_terms: D000818:Animals; D001011:Aorta / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass; D004195:Disease Models, Animal; D019054:Evoked Potentials, Motor; D005260:Female; D007036:Hypothermia, Induced; D008159:Lumbar Vertebrae; D020760:Spinal Cord Ischemia / Q000209:etiology* / Q000517:prevention & control*; D015607:Stents; D013552:Swine; D013895:Thoracic Arteries / Q000601:surgery*; D013904:Thoracic Vertebrae