Pressure changes in the arterial feeder to a cerebral AVM as a guide to monitoring therapeutic embolization.

Blood pressure changes, or lack of them, in the feeding pedicle to a cerebral arteriovenous malformation appear to be a more sensitive guide by which to monitor the progress of a therapeutic embolization than are fluoroscopic or serial angiographic changes. We have measured the feeder pressure in three patients before embolization with particulate materials and compared the pressure with subsequent measurements obtained during the progress of the procedure. When the feeder pressure has increased after particle infusion, even if fluoroscopic slowing of flow is not apparent, additional particulate infusion has soon resulted in slowing of flow and, finally, hemostasis. When the feeder pressure has not increased, we have changed to a larger-sized particle and then continued the procedure. Monitoring changes in feeder pressure is particularly helpful during the early stages of embolization; however, our end point is still the angiographic demonstration of flow arrest.