Giant Intracranial Fistulous Aneursym of Childhood

H. Kaptan, S. Birler, O. Kasimcan

Department of Neurosurgery, Ulus Hospital, Ankara, Turkey

 

Abstract

Background: An unusual giant intracranial vascular lesion in a two years old child is reported.

Case Description: The vascular pathology in this child has some characteristics. These are age of the patient, presence of giant varix/aneursym that has only one neck on the vertebral artery distal to the posterior inferior cerebral artery with fenestration of the parent artery. It had large draining veins arising from itself to cavernous sinus and probably therefore symptom of the patient was epistaxis and cured by clipping the neck of lesion or the single, feeder.

Conclusion: Intracranial vascular lesions during childhood are rare lesions which have different features when compared to adults. We had difficulty in giving a proper name to this unusual lesion because best to our knowledge no similar case has been reported in the literature.

Key Words: Aneurysm, Cavernous sinus, Childhood, Fenestration, Varix, Vertebral artery.

Introduction

Intracranial aneurysms of children are uncommon lesions with the frequency of 0.5% to 4.6% in large aneurysms series [5, 7, 8]. Aneurysms in infancy and early childhood (<2 years) are extremely uncommon. There are several distinct characteristic of this entity as follows; male predominance, presence of high number of this type aneurysms in posterior fossa and tendency to be large or giant. The symptoms are either subarachnoid hemorrhage of focal neurological deficits due to mass effect of large or giant aneurysms. Cerebral Angiography shows that the incidence of fenestration of vertebral artery is 0.3-2.0%. There are several reports of coexisiting fenestration and cerebral aneurysms [3]. Patients with giant intracranial varices have intracranial pressure, seizures, intracranial hemorrhage and cardiac failure. The mode of presentation is related with the age of the patient, the size of the intracranial fistula and the volume of the intracranial varix [4, 9].

In this case, an unusual giant fistulous aneurysm which originated from intracranial fenestrated vertebral artery with draining veins through the cavernous sinus, was treated successfully with clipping of the neck.

Case Report

A 2-year-old male with history of nasal bleeding, fatigue and tendeney to drowsiness admitted to our clinic. The patient was alert, oriented but slightly lethargic. Neurological examination was without any focal neurological deficit except bilateral papiledema. Cranial CT was performed and a posterior fossa lesion was diagnosed as the reason of hydrocephalus and MRI showed a giant vertebral artery (VA) aneurysm 30´30´35 mm, in size with hypointense and isointese areas. A cerebral angiogram which demonstrated the fenestration of right VA and the giant aneurysm, arising just distal to posterior inferior cerebral artery (PICA) (Fig.1), (Fig.2), (Fig.3).

A right paramedian suboccipital craniectomy with partial removal of occipital condyle and C1 laminectomy was performed through median skin incision in the sitting position with head slightly rotated to right side. Dura over the aneurysm dome was not opened completely because of severe adhesions at the right side of operation field. Extracranial portion and intracranial segment of vertebral artery was seen until its fenestration. A temporary clip was applied on the proximal part of the right vertebral artery for a safe dissection. The exit of the PICA, the neck of the aneurysm, the vertebrobasilar junction were identified. After the clip application to the neck of the aneurysm (Fig.4), the temporary clip on the vertebral artery was removed which has stayed for three minutes. The patient's postoperative course was uneventful; lethargy and epistaxis disappeared. The patient was discharged from the hospital on 10th postoperative day. Two months after the operation, postoperative angiograms revealed no filling of dome or abnormal venous structures (Fig.5). Because of the presence of persistent hydrocephaly on CT, the patient underwent ventriculoperitoneal shunt placement six months after the first operation. On follow up, 6 years later the patient was doing well without any complaints and neurologic deficits. CT revealed no mass lesion and hydrocephalus was improved.

Discussion

Aneurysm are extremely uncommon during infancy and early childhood (<2 years). In childhood aneurysms, the most common clincal presentation is subarachnoid hemorrhage. Giant aneurysms or vascular lesions produce compression and block of the cerebrospinal fluid pathways. Because of these reasons; subsequently cranial nerve deficits, brain stem dysfunction or hydrocephalus may develop. In giant aneurysms, clinical presentation may be atypical. This type of aneurysms occasionally simulate tumors and correct diagnosis may be difficult and result in a tragic end.

In our patient, presenting symptoms were epistaxis and lethargy. Several veins which drained the superior part of the aneurysmal sac were seen at operation. We thought that epistaxis probably originated from those veins which were draining into the cavernous sinus as seen on the preoperative angiograms. In our patient the hydrocephalus and/or compression of brain stem caused lethargy. It was due to the mass effect of this giant vascular lesion. Generally, neurological deficits due to the mass effect of a giant aneurysm are more severe in the posterior circulation than the anterior one. An arteriovenous fistula (AVF) is an abnormal connection between an artery and a vein that forms without an intervening capillary channel. Congenital arteriovenous fistula (AVF) produces a venous aneurysm usually involving an extracerebral vein [9, 1, 2].

We had difficulty to define this case as an aneurysm, a varix or an arteriovenous fistula. Because it had a venous component, we couldn't define it as an aneurysm. This case was not a fistula or varix because it didn' t have one or more feeder which were differentiated from parent artery; and on the opposite side, it had a relation with the parent artery via an aneurysm neck.

In the literature, Vinuela [9] reported a giant varix in which PICA drained, was 4 years old and similar to ours. But in this case, the lesion was located on the lateral side, it was a giant varix which was fed from 2 separate feeders and its drainage was to the sigmoid sinus. In the other case, Martin reported a giant arteriovenous varix in a 6.5 years old child who had isolate growth hormone deficiency. In this case, the giant varix was treated with clipping the fistulous connection which had a feeder from the apex of basilar artery [4].

In our case, venous drainage was from the infratentorial segment to cavernous sinus and epistaxis, chronic hemorrhage were seen. Because of all these reasons, anemia has appeared.

This clinical presentation is unique in the literature. In early embriologic development we know that the drainage of brain stem and cerebellum was into the cavernous sinus [6]. Because of having a multiple number of venous drainage and being in along segment; this lesion didn't cause cardiac failure.

In this case, preoperative attentive evaluation, operative positioning, reducing the tonus with temporary clipping and searching the existence of a lesion by following the vertebral artery in a narrow space, were stages of the treatment. In this type of cases, every case must be evaluated according to its own specialities. Because of this reason, interventional neuroradiology must be used as an adjuvant treatment mode. In early postoperative period of our case, although hydrocephaly was persistent, the patient was conscious. This also showed us that the reason of the letharg was the compression of brain stem.

We were unable to find a similar case in the literature, so we hesitated to name this case as a pure aneurysm or fistula. The clipping of the aneurysmal neck also cured the fistula, so we intend to call our case as a fistulous aneurysm or aneurysmatic fistula.

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