Manipulation of intracranial arteries is associated with consistent vessel diameter reductions during microsurgical aneurysm clipping.

To report the rate of diameter reduction of intracranial arteries during aneurysm clipping. Also, in the subset of ruptured aneurysm (RA) the relationship between diameter reduction and symptomatic vasospasm (SVS) Is investigated. A retrospective dataset containing demographics, aneurysm characteristics, vessel dynamics and SVS in adults with surgically clipped intracranial aneurysms was analyzed. The vessel diameters were recorded intraoperatively, both pre- and postclipping. SVS was assessed by transcranial doppler ultrasound or CT-angiogram in the presence of neurological deterioration. Backward multivariable logistic regression models were applied to define variables associated with SVS. A total of 117 surgically clipped adults with intracranial aneurysms were included of which 49 (42%) presented with subarachnoid hemorrhage due to a RA. Intraoperatively measured vessel diameters were smaller in the RA group compared to the non-RA group. The vessel diameter changes before and after placement of the surgical clip are comparable in all groups, with a mean reduction of 15% (RA, non-RA, SVS and no-SVS). Incidence of SVS was 57.1% (in RA group), mean age 53 years and 73.5% were women. Female sex was independently associated with the occurrence of SVS (p = .024). Surgical aneurysm manipulation leads to a consistent reduction of 15% in intracranial artery diameters. Although vessel diameters are smaller in patients with RA compared to non-RA, there is no difference in intraoperative vessel diameter dynamics for both groups. We found no association between the degree of vessel diameter reduction and the occurrence of symptomatic vasospasm in the RA group.