An investigation with serial angiography into the evolution of cerebral arterial spasm following aneurysm surgery.

Serial postoperative angiograms were performed in 28 patients with intracranial aneurysms, 26 of whom had presented with a subarachnoid hemorrhage. The clinical state and intracranial pressure (ICP) were also measured. Angiograms were performed in the ward using a cannula, which was passed into the proximal external carotid artery via the superficial temporal artery. Measurements of the vessel diameters were made, with the preoperative angiogram as a baseline. Patients could be placed into one of five groups depending on the presence or absence of significant arterial spasm, the clinical state of the patient, and the normality or otherwise of the ICP. No patient's condition deteriorated without an elevated ICP and/or significant arterial spasm. The study shows that this spasm is usually associated with a poor clinical state if it reaches a maximum 8 to 12 hours after the operation, although the clinical deterioration is not apparent for a further 6 to 12 hours. Knowledge of the natural history of postoperative arterial spasm may allow earlier treatment of the spasm, which may be more successful than delaying treatment until clinical deterioration has occurred. The worth of the varied drugs proposed for the treatment of spasm may be assessed using this type of protocol.