A prolonged spinal cord ischaemia model in pigs. Passive shunting offers stable central haemodynamics during aortic occlusion.
OBJECTIVE
to evaluate the effect of a modified aortic shunt on central haemodynamic variables during experimental thoracic aortic occlusion in a prolonged spinal cord ischaemia model.


METHODS
central haemodynamic variables were evaluated during aortic cross-clamping. In the shunt group (n=11), after the placement of proximal and distal aortic clamps, distal aortic perfusion was restored through an aortoiliac shunt via the left subclavian artery. In the no-shunt group (n=11), spinal cord ischaemia was achieved with only proximal aortic cross-clamping. The clamping time was 60 minutes in the shunt group and 30 minutes in the no-shunt group.


RESULTS
in the no-shunt group, all animals needed inotropic support, vasodilators and buffers during the experiment. None of these drugs were needed in the shunt group. In the no-shunt group, cross-clamping caused a significant increase in mean arterial pressure and heart rate compared to baseline values. These variables were stable in the shunt group during aortic occlusion. In the reperfusion period cardiac output, heart rate and arterial pCO(2)were significantly higher in the no-shunt than in the shunt group.


CONCLUSIONS
the present experimental spinal cord ischaemia model, using double aortic cross-clamping with shunt, offers improved central haemodynamics. This enables the study of prolonged selective spinal cord ischaemia without interaction from vasoactive drugs or systemic reperfusion.
Hellberg
A
A
Department of Surgery, University Hospital, Uppsala, Sweden.
Christiansson
L
L
Tulga Ulus
A
A
Bergqvist
D
D
Wiklund
L
L
Karacagil
S
S
D000818:Animals; D001013:Aorta, Thoracic / Q000601:surgery*; D001794:Blood Pressure / Q000502:physiology; D002021:Buffers; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output / Q000502:physiology; D002315:Cardiopulmonary Bypass; D002316:Cardiotonic Agents / Q000627:therapeutic use; D002496:Central Venous Pressure / Q000502:physiology; D003250:Constriction; D004195:Disease Models, Animal; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D007083:Iliac Artery / Q000601:surgery; D007511:Ischemia / Q000209:etiology*; D016343:Monitoring, Intraoperative; D010100:Oxygen / Q000097:blood; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D013116:Spinal Cord / Q000098:blood supply*; D013348:Subclavian Artery / Q000601:surgery; D013552:Swine; D013997:Time Factors; D014665:Vasodilator Agents / Q000627:therapeutic use
D002021:Buffers; D002316:Cardiotonic Agents; D014665:Vasodilator Agents; D002245:Carbon Dioxide; D010100:Oxygen