Hypogastric and subclavian artery patency affects onset and recovery of spinal cord ischemia associated with aortic endografting.

OBJECTIVE: Spinal cord ischemia (SCI) is a devastating complication associated with aortic aneurysm repair. The aim of the current study was to evaluate factors affecting outcomes from SCI associated with endovascular aortic aneurysm repair.
METHODS: A total of 1251 patients underwent endovascular repair of aortic aneurysm as part of a device trial between 1998 and 2010 utilizing endovascular abdominal aortic aneurysm repair (n = 351), thoracic endovascular aortic aneurysm repair (n = 201), fenestrated endovascular aortic aneurysm repair (n = 227), and visceral branched endografts (n = 472). Records and imaging studies were reviewed to supplement prospective outcome data. Demographics, type of repair, collateral bed (hypogastric/subclavian) patency, clinical presentation, and outcomes were evaluated on patients with SCI. Survival was calculated using life-table analysis.
RESULTS: SCI occurred in 2.8% (n = 36) of patients: abdominal aortic aneurysm, 0.3%, juxtarenal, 0.4%, thoracic aortic aneurysm, 4.6%, and thoracoabdominal aortic aneurysm, 4.8%). Four (11%) required carotid-subclavian bypass prior to endografting, and two underwent coverage of the left subclavian artery. Unilateral hypogastric artery occlusion was present in 11 (31%) patients prior to endograft placement, and three had bilateral occlusions. An additional seven patients had occlusion of at least one hypogastric artery during surgery. SCI was apparent immediately in 15 (42%) patients. Immediate onset of symptoms was observed in 73% of patients with at least one occluded collateral bed but in only 24% of those with patent collateral beds (P = .021). Of those presenting in a delayed fashion, nine (43%) had a clear precipitating event prior to onset of SCI (hypotension, n = 6, and segmental artery drain removal, n = 3). Recovery occurred in 24 (67%) patients, most within 7 days. Immediate presentation was a negative predictor of recovery (P = .025), as was occlusion of at least one collateral bed (P = .035). Mean follow-up was 22 ± 4 months with 30-day and 1-year survival of 92 ± 4.6% and 56 ± 8.3%. Survival was only 36% at 3 months in those with permanent SCI compared with 92% (P < .001) in those with temporary symptoms.
CONCLUSIONS: SCI continues to complicate aortic surgery despite the advent of endovascular therapy. Occlusion of a single collateral bed is associated with an increased risk for immediate onset of SCI and lack of recovery. These factors are harbingers of poor outcomes and increased short-term mortality. This may be prevented by preserving collateral bed patency in patients undergoing extensive endovascular procedures.