Circle of Willis Collateral During Temporary Internal Carotid Artery Occlusion I: Observations From Digital Subtraction Angiography

INTRODUCTION: Impaired collateral circulation can lead to stroke during carotid endarterectomy. Carotid stump pressure (CSP) is used as a surrogate measure of collateral flow. The objective was to determine whether anatomical features obtained from digital subtraction angiography correlate with CSP during temporary internal carotid artery occlusion. The second objective was to use these features in combination to predict CSP. METHODS: Digital subtraction angiographies from 102 patients obtained before endarterectomy were reviewed for anatomical variables including: degree of ipsilateral and contralateral carotid artery stenosis; patency of the anterior communicating artery; presence of cross-flow into ipsilateral middle cerebral artery branches; and size (\u3c or ≥1 mm calibre) of the ipsilateral proximal anterior cerebral (A1), the contralateral A1, and the ipsilateral posterior communicating arteries. At surgery, systemic mean arterial pressure (MAP) and CSP were recorded. Multiple regression analysis was used to assess for anatomical features significantly associated with CSP. A predicted CSP equation was applied to 54 subsequent patients and correlated with measured CSP. RESULTS: Variables correlating with CSP included MAP (p=0.001); the presence of severe contralateral carotid stenosis (p=0.002); patency of the anterior communicating artery (p=0.013); and the size of the contralateral A1 segment (p=0.029). Angiographic cross-flow, ipsilateral A1 size, and ipsilateral posterior communicating artery size were not significant. Predicted CSP correlated significantly with measured CSP (p\u3c0.0001; R 2=0.34). CONCLUSIONS: Anatomical features and systemic MAP are associated with carotid stump pressure during internal carotid artery occlusion and account for a significant amount of its variation

Mortality in vitamin K antagonist-related intracerebral bleeding treated with plasma or 4-factor prothrombin complex concentrate

Prothrombin complex concentrates (PCC) can rapidly normalise prolonged prothrombin time, induced by vitamin K antagonists (VKA). We conducted a multicentre retrospective study to investigate whether reversal of VKA coagulopathy with 4-factor PCC improves the survival of patients with VKA-related intracerebral haemorrhage as compared to plasma. We included 135 consecutive patients with VKA-related intracerebral haemorrhage treated either with plasma (mainly in Canada) or 4-factor PCC (The Netherlands and Sweden) for the reversal of VKA. Data on characteristics of the patients and the haemorrhage were collected. The volume of intracerebral haematoma was calculated from the first computed tomography (CT) scan. The unadjusted and adjusted odds ratio (OR) for 30-day all-cause mortality in both treatment groups was compared using logistic regression. Patients who received plasma (n=35, median 4 units) more often had diabetes, antiplatelet therapy, and intraventricular haemorrhage on the initial CT scans than patients who received PCC (n=100, median 22.5 IU/kg [interquartile range 20-26 IU], median of total dose 1,700 IU). The volume of intracerebral haematoma was larger in the plasma-treated group compared to the PCC-treated group (haematoma, mean 64.5 vs 36.0 cm(3); p=0.021). The unadjusted OR for all-cause 30-day mortality in the PCC group was 0.40 (95% confidence interval, 0.18-0.87; p=0.021) compared to the plasma group. After adjusting for the haematoma volume, bleeding localisation and age, the effect of PCC on mortality became non-significant. In conclusion, treatment with 4-factor PCC for VKA reversal in patients with intracerebral haemorrhage does not seem to reduce the 30-day all-cause mortality compared to plasma