A rare complication after mechanical thrombectomy: A case of acute hydrocephalus due to subarachnoid hemorrhage

Introduction: Acute hydrocephalus after mechanical thrombectomy is a rare complication. This case aims to draw attention to acute hydrocephalus developing in the setting of subarachnoid hemorrhage, to emphasize that this condition should be kept in mind in the differential diagnosis of sudden neurological deterioration after successful revascularization, and to underline the importance of early surgical intervention.Case: A 53-year-old man presented with sudden-onset left-sided weakness. The National Institutes of Health Stroke Scale (NIHSS) score was 18. Brain computed tomography (CT) showed no hemorrhage; intravenous tissue plasminogen activator was started, and he was taken to angiography for thrombectomy. Digital subtraction angiography (DSA) showed total occlusion of the M1 segment of the right middle cerebral artery (MCA); revascularization at the Thrombolysis in Cerebral Infarction (TICI) 2c level was achieved with a combination of stent retriever and aspiration. During the procedure, total occlusion of the pericallosal branch of the anterior cerebral artery A3 was detected (embolization to a new territory, ENT). Brief bleeding due to rupture was observed while the thrombus in A3 was being retrieved, and no further bleeding was seen afterward. The post-procedure NIHSS was 4. Four hours after thrombectomy, the patient became lethargic. The follow-up brain CT showed interhemispheric subarachnoid hemorrhage with an area consistent with contrast accumulation. When repeat imaging showed acute hydrocephalus, an urgent neurosurgery consultation was requested and an external ventricular drain (EVD) was placed. The follow-up CT after EVD showed resolution of the hydrocephalus and marked improvement in the level of consciousness. After the etiological work-up was completed, he was discharged with appropriate recommendations, and the modified Rankin Scale was 4 at the first-month assessment (Figure 1 and 2).Discussion/Conclusion: Symptomatic intracranial hemorrhage is the most feared complication of thrombectomy. Subarachnoid hemorrhage can develop in 5–6% of cases because of vessel perforation or endothelial irritation. Hydrocephalus after thrombectomy is rare; it is classically seen in posterior infarcts and to our knowladge, no case has been reported in the anterior circulation. This case is therefore noteworthy. Early diagnosis and surgical intervention can contribute to a favorable course; acute hydrocephalus should be kept in mind in sudden changes in consciousness.Keywords: