Mechanical Thrombectomy in Isolated Posterior Cerebral Artery Occlusion

Posterior cerebral artery (PCA) stroke comprises between 5% and 10% of ischemic strokes. It can be challenging to diagnose because of nonspecific and fluctuating symptoms, which may lead to delayed hospital admission and subsequent ineligibility for thrombolytic therapy options, especially in patients presenting with minor deficits. However, because of the PCA’s contribution to the vascular supply of eloquent brain areas, stroke caused by isolated PCA occlusion can lead to severe permanent disability and substantially impact the quality of life. There are no randomized study data regarding endovascular treatment (EVT) of PCA occlusion since none of the pivotal trials included these patients. While it would be intuitive to assume that a rapid recanalization leads to better outcomes also in this context, the benefit of endovascular intervention in these patients remains controversial and uncertain. We present a case of a 63-year-old noncompliant patient with multiple vascular risk factors and a previous history of two embolic strokes treated with tissue plasminogen activator (tPA). He was admitted due to a confusional state, left-sided weakness, and impairment of speech disturbances, which a nurse noticed during a dialysis session 2 h before the admission. His baseline NIHSS score was 12. Noncontrast cranial CT showed hypodense lesions in the left lateral middle cerebral artery (MCA) cortex and the right basal occipital lobe, consistent with previous ischemic infarctions, and did not reveal any acute ischemic brain lesions. CT angiography (CTA) revealed a cutoff of the right PCA in the P2 segment. CT perfusion (CTP) showed a sizeable mismatch between the ischemic core and penumbra. The patient underwent successful endovascular revascularization of the right PCA occlusion. The procedure was uneventful. Postprocedural noncontrast cranial CT showed diffuse intraparenchymal hyperattenuating lesions in the right occipital parasagittal area and right thalamus, consistent with microvascular extravasation of contrast into the infarcted tissue. Brain MRI performed on the following day confirmed subacute ischemic stroke in the territory of vascularization of the right PCA. He had an NIHSS of 9 on a postprocedure neurological examination. Treatment with low molecular weight heparin (LMWH) was started 24 h after the procedure. Further hospitalization was unremarkable. The patient was transferred to a rehabilitation facility with NIHSS of 8 and mRS of 4 within 10 days. The feasibility of endovascular treatment in isolated PCA occlusion is the main topic of this chapter.