Unruptured aneurysmal clipping complicated by delayed and refractory vasospasm: case report

Background: Delayed symptomatic vasospasm is a rare complication following clipping of an unruptured intracranial saccular aneurysm. There have been ten reported cases of delayed symptomatic vasospasm and only two of these occurred after 2 weeks from initial intervention. Our case is the first to document the refractory nature of such vasospasm despite aggressive first line therapy.

Case presentation: Here, we present a 67-year-old female who had surgical clipping of a 10x7mm right middle cerebral artery (MCA) bifurcation aneurysm. Her surgery and initial postoperative course were uncomplicated, but she presented with acute left hemiparesis, dysarthria, headache and vomiting on post-op day 29 secondary to vasospasm of M2. She was initially stabilized with intra-arterial verapamil then managed with volume expansion, permissive hypertension, and nimodipine. She developed recurrent vasospasm of M2 the following day and was again treated with intra-arterial verapamil. Magnetic resonance imaging (MRI) brain showed an infarction involving the right basal ganglia, frontal lobe, and parietal lobe and her hospital course was complicated by super-refractory status epilepticus. At her follow up appointment she displayed continued left lower extremity weakness, left visual field defect, and left-sided neglect.

Conclusions: Overall, cerebral vasospasms associated with unruptured aneurysms remain rare complications and are not often monitored for after initial recovery. Reviewing the documented cases highlights the unpredictability of when these events occur with our current knowledge. Current hypotheses for the mechanisms responsible for delayed and refractory vasospasms include: blood-derived breakdown products, mechanically induced vasospastic responses, and delayed reactions from the trigemino-cerebrovascular system (TCVS). The uncertainly of these events warrants further research and supports a strong argument for monitoring patients with initial surgical clipping up to a month out from their initial procedure.