We experienced rare combination of multiple irregular shaped aneurysms along the course of the feeding artery and arteriovenous malformation (AVM) in the posterior circulation. We could not explain which aneurysm was a cause of bleeding because all the aneurysms showed irregular in shape like pseudoaneurysms and location of the aneurysms was very close each other. We report two cases in which multiple irregular shaped aneurysms were related with AVMs and first episode of hemorrhage.
The association between arteriovenous malformations (AVMs) and arterial aneurysms is well known, with an incidence ranging from 2.7% to 23% (
We experienced two cases of rare combination of multiple irregular shaped aneurysms along the course of the feeding artery and AVM in the posterior circulation. We could not explain which aneurysm was a cause of bleeding because all the aneurysms showed irregular in shape like pseudoaneurysms and location of the aneurysms was very close each other. The patients had no history of previous subarachnoid hemorrhage (SAH). To our knowledge, few cases of multiple dysplastic aneurysms and ruptured pseudoaneurysm along the course of arterial feeders with AVMs presented in the literature. We report two cases in which multiple irregular shaped aneurysms were related with AVMs and first episode of hemorrhage.
First patient was 33-year-old man admitted with generalized tonic-clonic seizure for 5 minutes. The mental status was deep drowsy and there were no neurological deficits. He had no previous history of intracranial hemorrhage. A computed tomography (CT) demonstrated Fisher grade IV SAH along the both sylvian fissures, interhemispheric fissure, and dominantly in the premedullary and prepontine cistern and intraventricular hemorrhage in 3rd and 4th ventricles.
A digital subtraction angiogram (DSA) revealed two left anterior inferior cerebellar artery (AICA) aneurysms located at the premeatal and meatal branches and two left lateral pontine artery aneurysms and associated AVM distal from the aneurysms (
On following day, these aneurysms and AVM nidus were embolized with 33% mixture of n-butylcyanoacrylate (NBCA) and Lipiodol (
Second patient was 56-year-old man admitted with stuporous mental status. CT scan demonstrated Fisher grade IV SAH along the both sylvian fissures, basal cistern and intraventricular hemorrhage in 4th ventricle. This hemorrhagic event was first time for the patient.
A DSA revealed three irregular shaped aneurysms located at the meatal, dorsolateral branches of right AICA and AVM fed by the right AICA and right superior cerebellar artery (
On that day, these aneurysms and AVM nidus were embolized (
The occurrence of an intracranial saccular aneurysm of the feeding artery to an AVM is a well-known phenomenon (
Despite imperfect knowledge of the exact etiology and histology of pedicle aneurysms, these aneurysms are an important subgroup of aneurysms associated with AVMs and indicate a site of hemorrhage (
It should become the focus of attention in relation to treatment. Discovery of a pedicle aneurysm should prompt aggressive management of the aneurysm itself with embolization when AVM resection must be delayed or when radiosurgery is planned.
In our cases, the aneurysms were found in the near the meatal segment of the AICA (1 in premeatal, 3 in meatal, and 1 in dorsolateral segment) and proximal pontine artery. Andaluz et al. (
We suspect one of aneurysms must be pseudoaneurysm due to its association with recent hemorrhage. However, it was not easy to differentiate ruptured pseudoaneurysm from dysplastic flow related true aneurysms.
We attempted endovascular embolization with NBCA to obliterate all the aneurysms and to restrict AVM blood flow at a same time. After control of feeding pedicle having aneurysms, embolization of the other pedicles of AVM was done. Control of the aneurysms prior to the embolization of AVM feeders may avoid the catastrophic consequences of rebleeding. Residual AVM was amenable to radiosurgery.
In conclusion, we experienced two cases of multiple feeding pedicle aneurysms associated with posterior fossa AVMs presented with a one episode of SAH. These patients had no history of previous intracranial hemorrhage but all aneurysms had irregular shape like pseudoaneurysms. The differentiation of ruptured aneurysm from unruptured aneurysms was not possible. Embolization of aneurysms and AVM nidus with NBCA at a same time showed good clinical results. In cases of having remained AVM nidus, radiosurgery is recommended to obliterate the residual AVM nidus.
Case 1
Case 2