Search

Introduction There is some data suggesting vasodilatory effect of sympathetic blockade in patients with aneurysmal subarachnoid hemorrhage but the effect on medium‐sized intracranial arteries remains unclear. Methods Serial ipsilateral intracranial angiograms were obtained before and after percutaneous inferior sympathetic ganglion block. The angiogram files were imported to a DICOM reader, Horos Open‐Source Medical Image Viewer (Version 3.3.6).The percent change of arterial diameter (compared with pre‐blockage image) was calculated in intracranial internal carotid (ICA), middle (MCA) and anterior cerebral (ACA) arteries. We also assessed the inter‐observer reliability of arterial diameter change using the Bland‐Altman method after two raters independently measured the arterial diameter in 2 images with a total of 12 arterial measurements. Results In Patient 1, there was an increase in diameter of intracranial ICA, MCA and ACA at 1 minute (9.62%, 10.34%, 8.64%), 5 minutes (11.38%, 12.22%, 14.42%) and 10 minutes (8.66%, 11.30%, 5.50%), respectively.In Patient 2, there was an increase in diameter at 1 minute (0.72%, 2.08%, ‐1.75%), 5 minutes (12.04%, 0.64%, 4.50%), 10 minutes (6.86%, 7.23%, 10.38%), 20 minutes (9.45%, ‐2.16%, 13.32%), and 30 minutes (7.31%, 12.02%, 6.50%), respectively. The Bland‐Altman coefficient of variation was 1.32 (range 0.01 ‐5.57) with majority (5 out of 6, 83%) of the data points within the upper and lower limits of acceptance. Conclusions We observed vasodilation in medium‐sized intracranial arteries ipsilateral to the percutaneous inferior sympathetic ganglion block as early as one minute post treatment and persisting for at least until 30 minutes post blockade.