Mechanisms for possible ischemic damage to the spinal cord:
(1) thromboemboli
(2) interruption of the arterial blood supply, with loss of collateral circulation
(3) poor perfusion
Thromboemboli:
(1) atheroemboli from a "shaggy" aorta
(2) thrombosis
Interruption of the blood supply:
(1) failure to restore the pelvic arterial blood supply, especially in patients who have had a previous colectomy (associated with loss of collaterals from the inferior mesenteric artery)
(2) interruption of the arteria radicularis magna (artery of Adamkiewicz)
Poor perfusion:
(1) prolonged cross-clamping of the aorta
(2) rupture of an abdominal aortic aneurysm (with hypotension)
(3) hypotension
Factors reducing risk of ischemic injury:
(1) heparin therapy
(2) gentle handling of the arteries
