Bilateral carotid and vertebral rete mirabile presenting with a prominent anterior spinal artery mimicking a spinal dural AV fistula at MRI

Subarachnoid Hemorrhage Related to a Ruptured Anterior Spinal Artery Aneurysm Associated with Bilateral Vertebral Artery Occlusion

Objective

We report a rare case of a ruptured anterior spinal artery (ASA) aneurysm caused by bilateral vertebral artery (VA) occlusion.

Case Presentations

A 78-year-old man suddenly developed severe headache and slight hemiparesis, and was admitted to our hospital. Computed tomography (CT) revealed subarachnoid hemorrhage, mainly in the posterior fossa. On emergency angiography, the right VA terminated at the origin of the posterior inferior cerebellar artery (PICA), and anastomoses between the PICA and the anterior inferior cerebellar artery (AICA) were observed, in addition to a saccular 3-mm aneurysm with bleb originating from the PICA-AICA anastomosis. Left vertebral arteriography demonstrated that the left VA was occluded segmentally at the V4 level and revealed a tortuous arterial network filling the distal VA. Based on the location of the bleeding, the right VA aneurysm was considered to have ruptured. After balloon test occlusion of the right VA, parent artery occlusion was performed without complications. The patient had no neurological changes immediately after surgery, but several hours later, he stopped breathing. Retrospective analysis revealed an ASA aneurysm, which was determined to be the bleeding source. Although conservative treatment was performed, he died the fourth day after onset without neurological improvement.

Conclusion

In cases of subarachnoid hemorrhage associated with bilateral VA occlusion, an aneurysm formed by hemodynamic stress may be the source of hemorrhage. It is important to suspect aneurysms in the extracranial collaterals, such as the ASA, and intracranial collaterals such as the PICA-AICA anastomosis.

Isolated Trochlear Nerve Palsy in a Patient with Superior Cerebellar Rete Mirabile

BACKGROUND

Rete mirabile is a very rare vascular malformation and superior cerebellar artery (SCA) rete mirabile is not reported previously. We report a new case of rete mirabile of SCA initially detected by magnetic resonance imaging and transfemoral cerebral angiography.

CASE DESCRIPTION

This report illustrates the case of a 58-year-old man who presented with vertical diplopia. Brain magnetic resonance angiography and transfemoral cerebral angiography revealed a rete mirabile of SCA and 3-dimensional volume isotropic turbo spin echo acquisition, brain magnetic resonance imaging sequence, demonstrated that the cisternal segment of the ipsilateral trochlear nerve was compressed by this vascular malformation. We assumed that his cranial nerve palsy was caused by the rete mirabile of the right SCA. During the 8 weeks presence of diplopia, the patient was observed and the symptom was relieved spontaneously.

CONCLUSIONS

We provide a first report in the literature of rete mirabile involving the SCA and suggest a descriptive knowledge of rete mirabile for clinicians during decision-making of treatment.

Unilateral cervical and petrosal segment agenesis of the internal carotid artery with rete mirabile

The carotid rete mirabile (RM) is a physiological network between the internal and external carotid arterial systems. In this paper, an extremely rare case is presented, in which internal-external carotid artery anastomoses and a dilated ascending pharyngeal artery, due to unilateral agenesis of the cervical and petrous segments of the internal carotid artery (ICA), is presented.

Rete mirabile of the ICA: Report of three cases

Carotid rete mirabile is an arterial meshwork, occurring at the cavernous portion of the internal carotid artery (ICA). Rete mirabile in humans is not present during normal development of the intracranial circulation and hence is considered as a collateral pathway that develops as a consequence of segmental agenesis of the ICA. We report three cases of this rare entity encountered at our institute.

Rete mirabile associated with pial arteriovenous fistula: imaging features with literature review

A rete mirabile is a vascular network of intercommunicating small arteries or arterioles that replace the definitive adult artery supplying the brain. It supplies the brain in lower mammals but is not seen in normal human embryological development. A 26-year-old man presented with worsening tinnitus that was interfering with his sleep. On CT and digital subtraction angiography he was found to have a temporal lobe pial arteriovenous fistula with bilateral carotid and vertebral rete mirabile. The patient was offered open surgical and endovascular treatment options for pial arteriovenous fistula but he refused both and opted for conservative medical management. At 6-month follow-up he continued to have pulsatile tinnitus but was otherwise neurologically normal. We present the first described association of rete mirabile with pial arteriovenous fistula and discuss its clinical presentation and imaging features, with a review of the literature for bilateral carotid and vertebral rete mirabile.

Stenting for symptomatic vertebral artery stenosis associated with bilateral carotid rete mirabile: the long-term clinical and angiographic outcome

Symptomatic vertebral artery (VA) stenosis associated with bilateral carotid rete mirabile (CRM) has not been reported. We report the long-term clinical and angiographic outcome after stenting for symptomatic VA stenosis in the patient with bilateral CRM. This report is the first case that symptomatic VA stenosis associated with bilateral CRM was treated with stenting.

Carotid rete mirabile associated with subarachnoid hemorrhage from intracranial aneurysm: A case report and systematic review

Carotid rete mirabile (CRM) is a rare physiological vascular network in humans that is most often found in Eastern populations. This paper describes a CRM associated with an aneurysmal subarachnoid hemorrhage (aSAH) and discusses the details of the patient's treatment. A 28-year-old woman was admitted to our service with clinical signs and symptoms of a spontaneous aSAH. Computed tomography revealed a diffuse and extensive SAH (Fisher group IV), while an angiogram showed an abnormal collateral network in the right carotid system and a hypoplastic aspect to the internal carotid artery (ICA) on the same side. In addition, a saccular aneurysm with a diameter of 9.5 mm was present in the ophthalmic segment of the left ICA. This case is extremely uncommon. To avoid rebleeding in the patient, we successfully treated the patient by clipping the aneurysmal lesion. No procedure was performed for the CRM.

Bilateral carotid and vertebral rete mirabile with vein of Galen aneurysmal malformation: an unreported association

Rete mirabile is a fine meshwork of anastomosing vessels that replace the parent artery. A 30-year-old woman complained of slurring of speech, right eye proptosis, recurrent vomiting, and loss of bladder and bowel control, followed by drowsiness lasting 30-40 min, for the past 6 months. On cross sectional imaging and angiography, the patient was found to have a vein of Galen aneurysmal malformation, with bilateral carotid and vertebral rete mirabile. The patient was offered both endovascular and open surgical options but she refused any form of surgical treatment and opted for conservative management. At the 6 month follow-up, she continued to have occasional episodes of headache and vomiting but was otherwise normal. We describe the clinical, cross sectional, and angiographic features of this patient. A comparison with other patients with bilateral carotid and vertebral rete mirabile is also reported.

Bilateral segmental agenesis of carotid and vertebral arteries with rete mirabile and the prominent anterior and posterior spinal arteries as compensations

Agenesis of carotid or vertebrobasilar arteries with rete formation is rare. The anterior spinal artery or posterior spinal arteries supplying the posterior circulation with steno-occlusion or agenesis of bilateral vertebral arteries is also uncommon. Here, we describe a very rare case of concomitant segmental agenesis of bilateral carotid and vertebral arteries with collateral compensations from the prominent anterior spinal artery and posterior spinal arteries, as well as some transdural arterial networks which were considered a rete mirabile. We discuss its embryological and anatomic significance.

Unilateral rete mirabile as a result of segmental agenesis of the ascending petrous segment of the internal carotid artery: embryology, differential diagnosis and clinical implications

We describe an extremely rare case of unilateral rete mirabile in a young woman and discuss its significance in embryological development as well as its radiological aspects, differential diagnosis and potential clinical implications.