Prevention of Paraplegia during Thoracoabdominal Aortic Aneurysm Repair

A mouse model of ischemic spinal cord injury with delayed paralysis caused by aortic cross-clamping

BACKGROUND

Spinal cord ischemia and paralysis are devastating perioperative complications that can accompany open or endovascular repair surgery for aortic aneurysms. Here, we report on the development of a new mouse model of spinal cord ischemia with delayed paralysis induced by cross-clamping the descending aorta.

METHODS

Transient aortic occlusion was produced in mice by cross-clamping the descending aorta through a lateral thoracotomy. To establish an optimal surgical procedure with limited mortality, variable cross-clamp times and core temperatures were tested between experiments.

RESULTS

The onset of paresis or paralysis and postsurgical mortality varied as a function of cross-clamp time and core temperature that was maintained during the period of cross-clamp. Using optimal surgical parameters (7.5-min cross-clamp duration at 33°C core temperature), the onset of paralysis is delayed 24-36 h after reperfusion, and more than 95% of mice survive through 9 weeks after surgery. These mice are further stratified into two groups, 70% (n = 19/27) of mice developing severe hind limb paralysis and the remaining mice showing mild, though still permanent, behavioral deficits.

CONCLUSION

This new model should prove useful as a preclinical tool for screening neuroprotective therapeutics and for defining the basic biologic mechanisms that cause delayed paralysis and neurodegeneration after transient spinal cord ischemia.

Staged total exclusion of the aorta for chronic type B aortic dissection

Hybrid techniques using extra-anatomic bypass of critical aortic branches to enable endovascular treatment of complex aortic pathology have been previously described. A staged endograft repair of a complex, chronic Stanford type B aortic dissection with aneurysmal degeneration is reported in a 50-year-old man. The aneurysmal portion of the dissection extended from the distal arch to both common iliac arteries and was covered with an endograft from the ascending aorta to both external iliac arteries. Aortic arch branches, visceral, and renal arteries were bypassed using open technique. The patient had no neurologic complications. This case report illustrates the feasibility of the hybrid technique in selected high-risk patients when confronted with complex aortic pathology.