Intracranial arteriovenous malformation with partial contribution of extracranial external carotid artery

Contribution of meningeal arteries to cerebral arteriovenous malformations

We studied 52 patients with cerebral arteriovenous malformations (AVMs) by selective angiography and found that half received supply from meningeal branches of the external carotid artery. The frequency of meningeal arterial contribution was significantly higher in superficial AVMs, especially in the temporal, parietal and occipital regions. Larger lesions and higher shunt with steal phenomena on angiography were other factors favouring a meningeal arterial contribution. Diffuse AVMs with pial arterial networks around the nidus commonly received meningeal blood supply. In the past, meningeal feeders have been thought to be congenital, but this study suggests that they may develop during growth of the AVM.

Dual cerebral and meningeal supply to giant arteriovenous malformations of the posterior cerebral hemisphere

Seven cases of giant posterior hemisphere arteriovenous malformations are described. The significance of meningeal feeding vessels from the external carotid artery in addition to the primary cerebral supply through the internal carotid and vertebral arteries to these malformations is discussed. The necessity of bilateral selective external carotid arteriography is stressed, and the value of preoperative embolization is questioned.

Persistent embryonic veins in the arteriovenous malformations of the dura

The basic anatomy of the arteriovenous malformations of the dura is similar to that of the internal carotid (pial) malformations, as the arterial feeders in both these lesions arise from the internal carotid artery in the embryo. The venous drainage occurs through definite channels into the major venous sinuses. Therefore, the dural and the pial malformations should be classified together. The scalp malformations have no features similar to these groups. The prominent occipital artery is not necessarily the primary feeder. Whenever a prominent occipital artery is seen, special efforts must be made to locate the primary dural feeders arising from the internal carotid artery.

Spontaneous regression of an extra- and intracranial arteriovenous malformation. Case report

✓ The authors report a case in which an arteriovenous aneurysm located partly extracranially and partly in the posterior cranial fossa disappeared within 15 months without bleeding episodes or surgical intervention. The patient's clinical symptoms, headache, and cranial bruit, disappeared completely over the same period.

The haemodynamic effect of an intracranial arteriovenous anomaly. A Doppler-haematotachographic study

Determination of the mean blood flow velocity by means of Doppler haematotachography is suggested as an aid in evaluating the haemodynamic changes associated with an intracranial arteriovenous anomaly. A Doppler haematotachogram (HTG) was obtained in 13 patients with a radiologically diagnosed arteriovenous anomaly, with marked interindividual variations in dimensions and blood supply; in 6 of these patients the Doppler HTG was obtained before and after total neurosurgical extirpation. The large majority of the patients showed a significant increase in diastolic, and to a lesser degree in systolic flow velocity at the level of the common carotid artery. In most cases the flow velocity curve of the ophthalmic artery showed a decrease in amplitude. These are the most useful parameters in evaluating the haemodynamic effect of an intracranial arteriovenous anomaly. After the surgical removal of the anomaly, the carotid flow velocity decreased significantly. In the internal and external jugular veins, Doppler-haematotachographic pulse waves were registered for the first time. These may have been conducted from the internal carotid artery to the jugular veins via the arteriovenous anomaly. The usefulness of this parameter is reduced because of the cumbersome calculations required to determine the time within which an arterial pulse wave conducted via the arteriovenous anomaly reaches the jugular vein. Registration of this unusual pulse wave is solely of theoretical value.

Intraparenchymal arteriovenous malformations with predominant external carotid artery contribution

✓ Arteriovenous malformations located within cerebral parenchyma are usually supplied by intracranial vessels. An extracranial blood supply to these lesions is rare. The authors report their experience with two such cases and discuss the 21 comparable reports.