The effect of arteriovenous malformations on the distribution of intracerebral arterial pressures.
Academic Article
Overview
abstract
PURPOSE: To examine the distribution of arterial hypotension surrounding arteriovenous malformations (AVMs) using a standardized system of vascular zones. METHODS: Mean arterial pressures were recorded during superselective cerebral angiography in 96 patients with AVMs (before they underwent liquid polymer embolization) with the use of a system of vascular zones: E = extracranial internal carotid or vertebral artery; I = intracranial internal carotid or basilar artery; T = transcranial Doppler insonation site (A1, P1, M1); H = halfway to feeder, perfusing normal tissue and shunt; and F = feeder at site of N-butyl cyanoacrylate injection. Distal arterial pressure was measured contralateral to the AVM in an additional 12 patients (zone Hc). RESULTS: Zone pressures (mm Hg +/- SD) were E = 76 +/- 16, I = 69 +/- 15, T = 59 +/- 16, H = 47 +/- 13, and F = 39 +/- 15 mm Hg. Vessel/systemic ratios for the zones were E = 0.97 +/- 0.05, I = 0.86 +/- 0.08, T = 0.75 +/- 0.12, H = 0.61 +/- 0.13, and F = 0.50 +/- 0.18. Measurements were obtained in 29 patients in all five zones and all had similar mean values. Zone Hc pressure was 66 +/- 17 mm Hg and the ratio was 0.78 +/- 0.12, both greater than zone H values. CONCLUSION: Using a standardized system of anatomic vascular zones, we found a progressive and significant decrease in intracerebral arterial pressure in patients with AVMs that proceeded from the circle of Willis to the nidus. Large areas of parenchyma sharing the same parent arterial supply may be subject to chronic hypotension.
