Feeding arteries of the spinal cord at CT angiography before and after thoracic aortic endografting.

PURPOSE: To study the visualization of spinal cord feeding arteries in patients with complex thoracic aortic pathology undergoing endovascular aortic repair (EVAR) using an optimized protocol for multislice computed tomographic angiography (MSCTA). METHODS: Eighteen consecutive patients (13 men; mean age 63 years, range 45-79) with aortic type B dissections (n=5), chronic expanding aortic dissections (n=5), thoracic aortic aneurysms (n=6), or penetrating aortic ulcers (n=2) underwent 16-slice CTA before and after (mean interval 9 days) EVAR. Pulse rate and neurological status were documented. Quantitative density measurements were taken at regions of interest (ROI) in the ascending thoracic aorta and at the level of the diaphragm. Two experienced radiologists qualitatively assessed the posterior intercostal arteries (PIA; fully visible, partially visible, non-visible), dorsal branches (DB; visible/non-visible), and artery of Adamkiewicz (AKA; visible/non-visible) on multiplanar reformations and maximum intensity projection reconstructions. RESULTS: MSCTA was performed successfully in 17/18 patients before and after EVAR (1 patient was excluded after EVAR owing to rising creatinine levels). Before EVAR, MSCTA revealed 197/203 PIAs within the stented area, of which 179 were fully and 18 partially visible. No significant (p=0.37) difference was noted for overall PIA detection within the stented area on post-EVAR MSCTA (185/203 PIA), although only 124 were fully and 61 partially visible. Similar results were obtained for DB visualization. The AKA were seen in 10/17 patients pre EVAR and 9/17 post EVAR. In 2 patients, the AKA was localized within the stented aortic segment. ROI analysis revealed contrast densities of 427+/-89 HU and 398+/-84 HU on pre- and post-EVAR MSCTA, respectively. No neurological events were observed. CONCLUSION: The majority of posterior intercostal arteries and dorsal branches remain open after EVAR due to retrograde perfusion. High-resolution MSCTA permits accurate pre- and post-EVAR visualization of spinal cord feeding arteries in patients with thoracic aortic pathology.