[Diagnosis and therapy of basilar artery occlusion]

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.

[Management of acute basilar artery occlusion]

Basilar artery thrombosis is a life-threatening condition whose unfavorable spontaneous prognosis can only be improved by early detection and subsequent aggressive recanalization therapy. The therapeutic approach has not yet been standardized and ranges from intravenous thrombolytic therapy with pharmacological agents to experimental procedures of mechanical endovascular recanalization, but the availability of the treatment approach and location of the occlusion determine the procedure in individual cases. Multicenter studies will have to clarify which bridging therapy (single administration of i.v. rt-PA or in combination with GPIIbIIIb inhibitors) before endovascular treatment is superior in terms of effectivity and complication rate.

[Imaging techniques in diagnosis of brainstem infarction]

Twenty per cent of cerebral ischaemic infarctions involve tissue, supplied by the vertebrobasilar circulation. This overview of the current literature and our own experiences present the value of different imaging techniques (CT and MRI) and new developments for diagnosing brainstem infarction. Furthermore, the roles of invasive and noninvasive vascular imaging methods (computed tomographic angiography, magnetic resonance angiography, intra-arterial angiography, ultrasound) for evaluating vertebrobasilar stenosis and occlusion are described. The diagnostic workup of the most severe form of brainstem infarction, basilar artery thrombosis, is shown.