Retrospective analysis of contrast-enhanced computed tomographic findings related to obstructive shock due to ascending aortic dissection.

OBJECTIVE: The objective of this study was to evaluate contrastenhanced computed tomography findings related to obstructive shock due to ascending aortic dissection (AAD). METHODS: The computed tomography findings in 9 AAD patients with shock, 11 AAD patients without shock, and 18 control subjects were evaluated for (1) pericardial effusion, (2) diameter of the inferior vena cava, (3) periportal hypodensity, (4) retrograde reflux of contrast material, (5) aortic and visceral enhancement, and (6) other factors (peripancreatic edema, bowel thickening/dilatation). RESULTS: Patients with shock showed the highest ratio of pericardial effusion, periportal hypodensity, and retrograde reflux of contrast material; largest inferior vena cava diameter; stronger aortic enhancement in both the arterial and portal phases; lowered splenic and pancreatic enhancement in the arterial phase; and stronger visceral (especially adrenal) enhancement, except for the renal medulla in the portal phase. CONCLUSIONS: Computed tomography findings related to obstructive shock due to AAD reflected impaired diastolic filling, decreased cardiac output, and flow redistribution in visceral organs.