gms | German Medical Science

Objective: Critical hypoperfusion following aneurysmal subarachnoid hemorrhage is usually treated by induced hypertension (iHTN) and – if refractory – may be extended to intraarterial or intravenous nimodipine application (iaN, ivN) and/or balloon angioplasty (BA). However, implementation of these rescue efforts remains largely empirical for a lack of supporting evidence, while the associated risk profile is also unclear. The present study evaluates the safety and efficacy of conservative (iHTN) and extended (iaN, ivN, BA) rescue treatments (ERT) for cerebral vasospasm.

Methods: Forty-nine patients (mean age 54.6±12.4 years) necessitating iHTN ≥180mmHg and/or at least one ERT were prospectively enrolled into this study. To assess efficacy, we evaluated neurological status, functional monitoring (lactate/pyruvate ratio as determined by cerebral microdialysis, brain tissue oxygen =p_tiO₂, transcranial doppler ultrasonography) and imaging (CT perfusion, angiography) 24 hours periprocedurally and determined clinical outcome at 3-6 months. Safety parameters included immediate procedure-related complications as well as subsequent adverse effects in context of vasopressor therapy.

Results: In this cohort, 43 conservative (iHTN) and 51 extended rescue treatments (iaN n=20; BA n=13; BA+iaN n=6; ivN n=12) were initiated. No serious complications with endovascular treatment were noted. iHTN and iaN, but not BA or ivN resulted in significantly increased vasopressor requirements with reduction or termination of prophylactic enteral nimodipine treatment in 45% and 63% of cases, respectively (p<0.001). Neurological improvement was noted in 76% of awake patients with iHTN. Only iaN, but not BA or ivN resulted in significant improvement of p_tiO₂ (p<0.01) as well as improvement of cerebral metabolism in 50% of cases. A subgroup analysis showed that patients with systolic pressure <150mmHg prior to iHTN profited significantly more in terms of ptiO2 than patients >150mmHg (p<0.05). With iaN and BA, CTP and DSA were improved in 86 and 93% of cases, respectively, but only in 63% of cases with ivN and 59% in iHTN (CTP; DSA not available). In 49% of cases with iHTN additional ERT was required and 37% of ERT needed repeated treatment or remained ultimatively refractory. Overall outcome was favorable in 57% with sole iHTN and in 40% with additional ERT.

Conclusion: iHTN was well tolerated with reasonable outcome, but ultimately insufficient to forestall relevant hypoperfusion in half of all patients. Provided a detailed decision tree and treatment algorithm, ERT can provide a relatively safe and effective treatment option in those highly-selected patients where conservative treatment options are exhausted. In addition to the inherent risk profile of each ERT, efficacy as determined by functional assessment may vary and should be taken into consideration when opting for extended rescue therapies.