gms | German Medical Science

Objective: Selective intra-arterial application of nimodipine and transluminal balloon angioplasty (TBA) is widely used as rescue therapy in severe cerebral vasospasm (CVS) after subarachnoid haemorrhage (SAH). Both procedures may achieve a dilatation of spastic cerebral arteries. However, data regarding the efficacy in the prevention of cerebral infarction are scarce and the indication for these procedures is contended. Therefore, we prospectively characterized the efficacy of these interventions by using the tissue at risk concept defined as mismatch in the MR perfusion (PWI) /diffusion (DWI) weighted imaging.

Methods: Patients suffering from SAH received an MRI in suspicion of CVS or routinely on day 7±2. In case of a proven PWI/DWI mismatch an angiography (DSA) was performed. Proximal CVS was treated by TBA. If spastic vessels were not accessible for TBA a selective intra-arterial application of nimodipine was performed. After 48±12 hours a control MRI was performed and the DSA including therapeutic procedures repeated in case of a new or remaining mismatch. For the assessment the brain was divided into 19 segments facilitating the placement of regions of interest for PWI measurement. Therefore, a direct correlation between the PWI deficit and the DWI lesion could be achieved. A major infarct was defined as DWI lesion ≥50% of a segment. Clinical outcome was determined by modified ranking scale (mRS) after 6 month. A favourable outcome was defined as mRS ≤2.

Results: Between 01/2006 and 11/2007 25 patients suffered from severe CVS resulting in at least 1 tissue at risk segment and a significant correlating CVS in the DSA. 48 treatment cycles each consisting of initial MRI, DSA and control MRI were performed: 12 patients 1 cycle, 7 patients 2 cycles, and 6 patients between 3 and 5 cycles. During these cycles 95 segments at risk were identified and subsequently treated by an intervention. In 17 (18%) of these segments and in 19 segments, which were not identified as tissue at risk a major infarct occurred. In 16 patients (64%) a new major infarction could be prevented. 15 patients had a favourable outcome.

Conclusions: The present series suggest that an interventional treatment of severe CVS employing the tissue at risk concept could prevent a new major infarction in approximately two third of the patients. However, the efficacy of these procedures containing tremendous periprocedural and diagnostic expenses has to be evaluated in randomized investigations.