title: Importance of extrasegmental vessels for spinal cord blood supply in a chronic porcine model.
abstract: IObjective: Our purpose was to investigate the interaction of the important components of spinal cord blood supply in the pig model to enable its use for future studies of spinal cord protection.
  
  
  METHODS
  25 juvenile pigs (20-22 Kg) underwent serial intercostal (IC) or lumbar artery (LA) ligation until disappearance of motor evoked potentials (MEPs). Pigs underwent sequential craniocaudal (IC/LA ligation alone (n=5); following clamping of both subclavian arteries (n=4)m, or clamping of the median sacral artery (MSA, n=4); preceded by clamping of the subclavian arteries (n=4), or of the MSA (n=4). RESULTS were verified by Tarlov's scores and perioperative angiography.
  
  
  RESULTS
  All animals with MEP loss suffered postoperative paraplegia. Groups were equivalent with regard to stable arterial pressures throughout the experiment, temperature and other physiological parameters. Mean number of clamped IC/LA before MEP loss for cranio-caudal clamping direction was 12.8 +/-0.8 for segmental arteries isolated, 9 +/-0.8 if both subclavian arteries were ligated previously and only 4.3 +/- 0.5 IC if the median sacral artery was clamped before. Mean number of clamped LA for caudo-cranial clamping direction was 5.8 +/-0.9 for segmental lumbar arteries, 5.5 +/-0.6 LA if both subclavian arteries were ligated previously and 3.5 +/-0.6 if the median sacral artery was clamped before.
  
  
  CONCLUSIONS
  This study confirms the importance of lumbar and MSA arteries to cord viability. It documents the interaction of the subclavian and MSA (roughly equivalent to the hypogastric arteries in humans) with segmental vessels in providing spinal cord blood supply. It also provides the physiologic basis for use of the pig model for studies of spinal cord protection in aortic surgery.
authors.affiliation: Departments of Cardiothoracic Surgery, Neurosurgery and Biomathematics Mont Sinai School of Medicine/New York University New York, NY, USA.
authors.forename: Justus T
authors.initials: JT
authors.lastname: Strauch
authors.forename: David
authors.initials: D
authors.lastname: Spielvogel
authors.forename: Alexander
authors.initials: A
authors.lastname: Lauten
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Howard
authors.initials: H
authors.lastname: Shiang
authors.forename: Donald
authors.initials: D
authors.lastname: Weisz
authors.forename: Carol A
authors.initials: CA
authors.lastname: Bodian
authors.forename: Randall B
authors.initials: RB
authors.lastname: Griepp
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal; D001013:Aorta, Thoracic / Q000601:surgery; D017545:Aortic Aneurysm, Thoracic / Q000601:surgery; D001158:Arteries / Q000601:surgery; D019054:Evoked Potentials, Motor; D006801:Humans; D010264:Paraplegia / Q000517:prevention & control; D013116:Spinal Cord; D013552:Swine