Treatment and Clinical Outcome in Patients With Basilar Artery Occlusion

Diagnostic and Prognostic Impact of pc-ASPECTS Applied to Perfusion CT in the Basilar Artery International Cooperation Study

BACKGROUND AND PURPOSE

The posterior circulation Acute Stroke Prognosis Early CT Score (pc-APECTS) applied to CT angiography source images (CTA-SI) predicts the functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS). We assessed the diagnostic and prognostic impact of pc-ASPECTS applied to perfusion CT (CTP) in the BASICS registry population.

METHODS

We applied pc-ASPECTS to CTA-SI and cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) parameter maps of BASICS patients with CTA and CTP studies performed. Hypoattenuation on CTA-SI, relative reduction in CBV or CBF, or relative increase in MTT were rated as abnormal.

RESULTS

CTA and CTP were available in 27/592 BASICS patients (4.6%). The proportion of patients with any perfusion abnormality was highest for MTT (93%; 95% confidence interval [CI], 76%-99%), compared with 78% (58%-91%) for CTA-SI and CBF, and 46% (27%-67%) for CBV (P < .001). All 3 patients with a CBV pc-ASPECTS < 8 compared to 6/23 patients with a CBV pc-ASPECTS ≥ 8 had died at 1 month (RR 3.8; 95% CI, 1.9-7.6).

CONCLUSION

CTP was performed in a minority of the BASICS registry population. Perfusion disturbances in the posterior circulation were most pronounced on MTT parameter maps. CBV pc-ASPECTS < 8 may indicate patients with high case fatality.

Basilar artery thrombosis: imaging and endovascular therapy

PURPOSE

Basilar artery thrombosis represents a rare type of ischaemic stroke with a mortality rate of 80%-90% if not promptly treated. The aim of our study was to review our experience with computed tomography angiography (CTA) in the diagnosis of basilar artery thrombosis and its treatment with endovascular procedures.

MATERIALS AND METHODS

Our retrospective study is based upon 59 nontrauma patients with episodes of sudden loss of consciousness. Patients were investigated using unenhanced brain CT followed by intracranial CTA (16-slice CT) when no parenchymal haemorrhage was detected. Patients with a CTA diagnosis of basilar artery thrombosis were considered for endovascular treatment. CTA accuracy was evaluated by considering the 12 patients who underwent endovascular angiography (the gold standard). The success of endovascular therapy was evaluated by considering the degree of microcirculatory reperfusion.

RESULTS

After the exclusion of 33 patients affected by parenchymal or subarachnoid haemorrhage, the final study consisted of 26 patients who underwent CTA. Basilar artery thrombosis was diagnosed in 15 of them, and 12 were treated at our institution. The comparison between CTA and endovascular angiography showed 100% agreement in evaluating occlusion site and extension. Seven patients underwent intra-arterial lysis, and five underwent mechanical clot removal.

CONCLUSIONS

CTA, with its wide availability and rapid execution times, is the most indicated examination in the case of suspected basilar artery thrombosis. Although there is a lack of randomised controlled prospective studies suggesting the most appropriate therapeutic approach to basilar artery thrombosis, our study lends weight to the role of interventional neuroradiology in the treatment of this condition.

Therapy of Acute Basilar Artery Occlusion

Background and Purpose— While intravenous recombinant tissue plasminogen activator (rt-PA) has been approved for acute stroke therapy within 3 hours, the optimum management of basilar artery occlusion (BAO) is still a matter of debate. We compared intraarterial thrombolysis with the combined bridging approach of intravenous abciximab and intraarterial thrombolysis with rt-PA (bridging therapy) in an observational, longitudinal, monocenter study.

Methods— Between 1998 and 2006, information for 106 patients with acute BAO were prospectively entered into a local database. Patients eligible for treatment received either intraarterial thrombolysis with rt-PA alone (intraarterial thrombolysis) or were treated with intravenous abciximab and intraarterial rt-PA (bridging therapy). Outcome parameters were recanalization of the basilar artery according to Trial in Myocardial Infarction criteria, survival, and reduction of severe disability and death at 3 months. Logistic regression was used to identify independent predictors for recanalization, survival, and clinical outcome.

Results— Of a total of 106 patients with confirmed BAO, 87 patients underwent subsequent angiography. Among those, 75 patients were identified who received the full treatment protocol. Patients in the bridging group had a better recanalization rate (83.7% vs 62.5%; P =0.03), a higher survival rate (58.1% vs 25%; P =0.01), and a better chance for an outcome with no or only mild to moderate disability (modified Rankin Scale score, 0–3; 34.9% vs 12.5%; P =0.02). Symptomatic intracerebral hemorrhage rates were comparable in both groups (14% in the bridging group vs 18.8%; P =0.41). Independent predictors for recanalization were age (OR, 0.95; 95% CI, 0.91–0.99), atrial fibrillation (OR, 6.53; 95% CI, 1.14–37.49), and bridging therapy (OR, 3.37; 95% CI, 1.02 to 11.18). Independent prognostic factors for outcome were Glasgow coma scale score at presentation (OR, 1.24; 95% CI, 1.03–1.45) and the combination of bridging therapy with successful recanalization (OR, 3.744; 95% CI, 1.04–13.43).

Conclusion— Bridging therapy for acute BAO with intravenous abciximab and intraarterial rt-PA appears to be safe and yields higher recanalization and improved survival rates, as well as an overall improved chance for a better outcome.