Background: In the acute stage following subarachnoid hemorrhage (SAH), prolonged cerebral circulation time reflects increased intracranial pressure (ICP), which can lead to irreversible brain damage. We evaluated the ability of cerebral circulation time to predict outcome in SAH patients.
Methods: We prospectively studied 40 consecutive patients treated for SAH according to standard intensive care guidelines. Lateral views in preoperative carotid digital subtraction arteriograms (DSA) were used to determine arteriovenous transit time (AVTT), defined as interval from initial opacification of the intracranial internal carotid artery to that of the Rolandic vein. We then analyzed relationship of AVTT to other prognostic parameters and outcome.
Results: AVTT depended on initial Glasgow Coma Scale score (GCS), ranging from 3.4 to 8.0 seconds (mean: 5.4) when initial GCS was 13 to 15; from 4.5 to 8.7 seconds (mean: 6.4) when initial GCS was 7 to 12; and from 5.8 to 15.0 seconds (mean: 9.1 seconds, excluding angiograms with nonfilling) when initial GCS was 3 to 6. AVTT correlated significantly with prognosis, longer AVTT predicting poorer outcome. No patient with an AVTT above 12 seconds recovered to a functioning state.
Conclusions: AVTT obtained from routinely performed acute-phase DSA in SAH patients reflects ICP and functional prognosis, representing a cost-effective, practical, and reliable outcome predictor.