Hemodynamic effects of preoperative embolization in cerebral arteriovenous malformations: evaluation with transcranial Doppler sonography.
A series of 83 patients with cerebral arteriovenous malformations is presented. All patients were evaluated with transcranial Doppler sonography. Thirty-two patients were treated with staged embolization and surgery: 19 of these patients were operated on within 4 weeks of the last embolization, and the remaining 13 patients underwent surgery 6 months or more from embolization. Transcranial Doppler sonography performed 1 day after embolization showed a significant (> 60%) reduction of main feeder flow velocity in 72% of patients after the first embolization and in 45% of patients after the second embolization. In no case did such a significant reduction occur after the third embolization. A flow redistribution in the basal vessels (defined as an increase in flow velocity of at least 30% of the initial value) occurred only in patients after the first embolization (64%). On delayed post-embolization studies, complete recovery of flow velocity in the embolized vessel occurred in 46% of patients, and sonographic recruitment of new feeders occurred in the remaining 54%. When main feeder flow velocity (mean) was higher than 120 cm/s after embolization and before surgery, the incidence of postoperative hyperemic complications (cerebral edema and/or intracerebral hematoma) was significantly higher than in patients with a mean flow velocity under 120 cm/s. It is concluded that transcranial Doppler sonography is a valuable method for a noninvasive hemodynamic assessment of shunt flow in arteriovenous malformations, and it permits a physiological monitoring of hemodynamic changes after embolization and allows more precise indications regarding further stages of embolization and timing of surgery after embolization.
Chioffi
F
F
Department of Neurosurgery, Verona City Hospital, Italy.
Pasqualin
A
A
Beltramello
A
A
Da Pian
R
R
D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D016063:Blood Loss, Surgical; D001810:Blood Volume / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D002540:Cerebral Cortex / Q000098:blood supply; D003971:Diastole / Q000502:physiology; D004453:Echoencephalography / Q000295:instrumentation*; D004621:Embolization, Therapeutic; D005260:Female; D005583:Fourier Analysis; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D006940:Hyperemia / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011300:Preoperative Care; D012039:Regional Blood Flow / Q000502:physiology; D013599:Systole / Q000502:physiology