Direct measurement of mean and pulsatile blood pressure at operation in human intracranial saccular aneurysms.

✓ Mean and pulsatile intra-aneurysmal blood pressures were recorded from four cases of human intracranial saccular aneurysms at the time of operative exposure. In each case the mean intra-aneurysmal pressure equalled the mean systemic arterial pressure, and the intra-aneurysmal pressure was pulsatile. The results demonstrate that, contrary to the findings of another report, intracranial aneurysms are subjected to the full force of systemic blood pressure.