Aneurysmal subarachnoid haemorrhage with a broad-necked anterior communicating aneurysm
A 52-year-old woman presents with a sudden thunderclap headache and transient loss of consciousness. On arrival she is drowsy but follows commands, with a Glasgow Coma Scale score of 14 and no focal motor deficit. CT shows diffuse subarachnoid blood, Fisher grade 3, and moderate ventriculomegaly. CT angiography shows a 7 mm anterior communicating artery aneurysm with a broad neck and a dome-to-neck ratio of 1.4. Serum sodium is 132 mmol/L. She is a non-smoker with no hypertension and no prior medical history. The interventional radiology suite is available during daytime hours, and the operating theatre can be staffed within 2 hours. The family is anxious and asks whether she will need a shunt.
1. Within what time frame would you secure the aneurysm, and how do you choose between endovascular coiling and surgical clipping? What specific features in this case drive the decision?
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Secure the aneurysm as early as feasible, ideally within 24–72 hours, to prevent rebleeding, which peaks in the first days and carries high mortality. The choice is multidisciplinary, based on aneurysm anatomy, patient age, grade, and local expertise. Endovascular considerations: coiling avoids craniotomy and may be preferred in poor-grade patients, but this aneurysm has a broad neck and a dome-to-neck ratio of 1.4, which increases the risk of coil protrusion and incomplete occlusion. Stent-assisted coiling or balloon remodelling is possible but requires antiplatelet therapy, which complicates EVD management. Surgical considerations: clipping gives durable occlusion and allows evacuation of clot, but requires craniotomy and brain retraction. Age 52 and good-grade status favour a durable repair, so clipping is a reasonable first choice if the neck is truly broad and the surgeon has expertise. A hybrid decision with both teams reviewing the angiogram is best. Do not delay definitive treatment for moderate ventriculomegaly alone; place an EVD if the patient is symptomatic, then proceed.
2. How would you manage the ventriculomegaly and the risk of delayed cerebral ischaemia in the first 14 days?
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Place an external ventricular drain if the patient has a decreased level of consciousness, upward gaze palsy, or enlarging ventricles on repeat imaging, because obstructive or communicating hydrocephalus can worsen the grade. Use a tunnelled, antibiotic-impregnated catheter, keep the drain at a height that maintains gradual drainage, and avoid excessive CSF removal that could cause aneurysm rebleeding before securing. Wean the drain after securing the aneurysm if the patient tolerates clamping. Delayed cerebral ischaemia: start nimodipine 60 mg every 4 hours, maintain euvolemia and normal sodium, and avoid hypotension. After the aneurysm is secured, permit induced hypertension for clinical vasospasm. Monitor with transcranial Doppler and CT angiography or catheter angiography if there is a new deficit. Daily neurological examination is essential. Treat hyponatraemia carefully: this patient’s sodium of 132 mmol/L may reflect cerebral salt wasting or SIADH; use isotonic fluids and avoid rapid correction. A shunt is needed only if hydrocephalus persists after weaning.
3. The family asks whether she will need a shunt and how you will decide. What is your reasoning and what alternatives would you discuss?
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Explain that hydrocephalus after subarachnoid haemorrhage is common and often transient. The decision depends on whether the ventricles remain enlarged and the patient remains symptomatic after the EVD is weaned. A reasonable pathway is to clamp the drain for 24–48 hours while monitoring the neurological examination, intracranial pressure if available, and ventricular size. If the patient develops headache, drowsiness, upward gaze palsy, or radiological re-expansion, the drain is reopened and a permanent ventriculoperitoneal shunt is considered. If the patient tolerates clamping and imaging is stable, the EVD is removed. Alternatives include a lumboperitoneal shunt in selected communicating hydrocephalus, but it is less reliable after subarachnoid blood. Endoscopic third ventriculostomy is generally not effective in this setting because the obstruction is at the arachnoid granulations. Discuss shunt risks: infection, overdrainage, subdural haematoma, and revision. Document the weaning trial and the family’s understanding.