Topic: F. Clinical Cardiothoracic/Vascular
Quantifying the Importance of Intercostal Revascularization in Thoracoabdominal Aortic Surgery
Charles W Acher, Martha M Wynn, Mathew Mell, Girma Tefera, John Hoch
University of Wisconsin, Madison, WI
OBJECTIVE(S): We previously demonstrated an 80% reduction in paraplegia risk using a paradigm that maximizes metabolic protection and collateral perfusion with moderate hypothermia, endorphin receptor antagonist, steroids, cerebrospinal fluid drainage, intercostal ligation, and optimizing hemodynamic parameters. This report details paraplegia risk factors and demonstrates that intercostal revascularization for the last 3 years further reduced our paraplegia risk index by 75%.
METHODS: We evaluated 637 patients who had thoracic or thoracoabdominal aneurysm repair for factors that affected paraplegia risk including aneurysm extent, acuity, cardiac function, blood pressure(MAP), and cerebrospinal fluid drainage with naloxone(CSFDN). We evaluated the effect of intercostal reimplantation(IRP) using a highly accurate (r2>0.88) paraplegia risk index we developed and published previously.
RESULTS: Fifty-eight percent of patients were male with a mean age of 67. Thirty-four percent were acute with rupture, acute dissection, mycotic aortitis, and trauma. Seventy-six(22%) had dissections. There were 35 patients with postoperative paraplegia or paraparesis(5.4%). Significant factors by univariate analysis were Crawford Type 2(p<.0001), acuity(p=.0102), CSFDN(p=.0144), cardiac index(p=.0286), MAP during crossclamp(p=.0279), and IRP(p=.0290). In multivariate modeling, aneurysm extent, CSFDN, and acuity remained significant (p<.02). The paraplegia risk index declined from 0.20 to 0.05(p<.03).
CONCLUSIONS: These findings suggest that factors which affect collateral blood flow and metabolism account for approximately 80% of paraplegia risk and intercostal blood flow accounts for 20% of risk. This suggests a significant limit to paraplegia risk reduction in thoracoabdominal endograft patients. Early results in this emerging field support this prediction of high paraplegia risk with thoracoabdominal branched endografts with extensive aortic coverage.