Effect of intrathecal magnesium sulfate solution injection via a microcatheter in the cisterna magna on cerebral vasospasm in the canine subarachnoid haemorrhage model.

OBJECTIVE: To evaluate intracisternal injection of magnesium sulfate (MgSO(4)) solution via a lumbar catheter for the treatment of cerebral vasospasm in the canine subarachnoid haemorrhage (SAH) model. MATERIALS AND METHODS: SAH was induced in 7 beagle dogs using the dual haemorrhage model. Vertebral angiography was repeated on Day 1 (before SAH), and on Day 7 (during cerebral vasospasm) before and 1.5 hours after injection of 0.5 mL/kg of 15 mmol/L MgSO(4) in Ringer solution via the tip of a microcatheter placed in the cisterna magna from the lumbar spine. RESULTS: After injection of MgSO(4) solution, the cerebrospinal fluid magnesium ion concentration significantly increased to 3.89 ± 0.97 mEq/L (P < 0.01) from the baseline value (1.49 ± 0.07 mEq/L). The arterial diameters of the basilar artery (BA), vertebral artery (VA), and superior cerebral artery (SCA) on Day 1 were 1.26 ± 0.19 mm, 1.10 ± 0.13 mm, and 0.74 ± 0.21 mm, respectively. On Day 7 before injection, the arterial diameters of the BA, VA, and SCA significantly decreased to 0.75 ± 0.27 mm, 0.74 ± 0.25 mm, and 0.36 ± 0.21 mm, respectively (P < 0.01), due to vasospasm, and were significantly increased to 0.91 ± 0.27 mm (P < 0.01), 0.91 ± 0.31 mm (P < 0.05), and 0.54 ± 0.14 mm (P < 0.01), respectively, after intracisternal injection of MgSO(4) solution. CONCLUSIONS: Intracisternal MgSO(4) therapy using a microcatheter from the lumbar spine may be effective against vasospasm in the clinical setting of endovascular treatment of ruptured aneurysm.