Continuous Intra-arterial Nimodipine Therapy in SAH Patients With Refractory DCI-Factors Associated With Insufficient Response and Unfavorable Outcome.

BACKGROUND

Continuous intra-arterial nimodipine infusion (CIAN) is an endovascular rescue therapy for refractory delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). Response and recurrence remain incompletely characterized.

METHODS

We retrospectively analyzed aSAH patients treated with CIAN (2016-2023) for imaging-confirmed vasospasm with perfusion deficits refractory to induced hypertension and intermittent intra-arterial nimodipine; microcatheters were placed in internal carotid or vertebral arteries. Analyzed variables included clinical characteristics, aneurysm parameters, WFNS, modified Fisher score (mFS), treatment response, vasospasm recurrence, DCI-associated infarctions, CSF diversion, and 6-month modified Rankin Scale (mRS). Sufficient response was defined as >75% restoration of baseline vessel caliber with perfusion improvement.

RESULTS

Of 36 patients (mean age 53 ± 12 years; 75% female), 16 (44%) responded sufficiently and 20 (56%) insufficiently. Recurrence after discontinuation occurred in 14 (39%); 7 (19%) required repeat CIAN. Insufficient response was associated with higher WFNS and mFS, multiple aneurysms, and generalized vasospasm. Insufficient response co-occurred with more DCI-related infarctions and unfavorable outcome but, given the overlap with baseline severity markers, likely reflects severe underlying vasospasm biology rather than an independent therapeutic effect. Procedure-related complications were uncommon and not associated with infarction or outcome deterioration.

CONCLUSIONS

CIAN is a feasible endovascular rescue strategy in selected patients with refractory DCI, although recurrence was common. Insufficient response clustered with markers of severe disease-higher WFNS and mFS, younger age, multiple aneurysms, generalized vasospasm-and was associated with unfavorable outcome. This study generates hypotheses for prospective studies.