[ Neurosurgery ] SAH 4

SAH surgery – early vs late factors

Early with good medical and neurological condition or associated ICH, late (after 10 days) with poor clinical condition.

SAH – early complication (first 3 days)

Rebleeding.

SAH – late complications (after 3 days)

Vasospasm and chronic communicating hydrocephalus.

Rebleeding after SAH – significance

Most common complication overall, mortality 70%, most likely on the first day.

Rebleeding after SAH – risk course

4% on day 1 (rising 1.5% each day), 15 to 20% within 2 weeks, 50% within 6 months.

Rebleeding after SAH – prevention

Secure the aneurysm (clipping).

Hyponatremia after SAH

Most common electrolyte disturbance, usually during 3H treatment.

Cerebral salt wasting vs SIADH

Cerebral salt wasting is hypovolemic hyponatremia, SIADH is euvolemic.

Vasospasm – other names

Cerebral angiopathy or DIND (delayed ischemic neurologic deficit).

Vasospasm – pathophysiology

Poorly understood, vasoconstrictors in CSF, with mediators oxyhemoglobin and endothelin, plus iron, noradrenaline, TXA2, and free radicals.

Vasospasm – timing

Never before day 3 (peak days 5 to 7).

Vasospasm – significance

More common in aneurysmal SAH, the most common cause of morbidity (severe morbidity 7%, mortality 7%).

Vasospasm – risk factors

High clinical grade (WFNS, Hunt and Hess) and more blood on CT (Fisher grade III).

Clinical vs radiological vasospasm

Clinical (20 to 30%) only after day 3 with new headache, lethargy, focal deficits, or hyponatremia, radiological (30 to 70%) any time from day 0 to 21 with arterial narrowing and slow contrast filling.

Vasospasm – prevention measures

3H protocol, calcium channel blockers (nimodipine, nicardipine), with or without dexamethasone.

Nimodipine in SAH – effect

Minimal effect on preventing vasospasm, main goal is neuroprotection by stabilizing intracellular Ca.

Vasospasm – endovascular treatment

Balloon angioplasty and intra-arterial papaverine.

Follow-up after SAH

At 3, 6, 12, 24, and 36 months, and screen asymptomatic 1st degree siblings.

Berry aneurysm – size classification

Small under 1 cm, large 1 to 2.5 cm, giant over 2.5 cm.

Giant berry aneurysm – presentation

Bleeding (35%), the rest with TIAs, seizures, or mass effect