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Bilateral Rete Mirabile Intracranial (Vascular) Anastomosis in Man

1968; Radiological Society of North America; Volume: 90; Issue: 1 Linguagem: Inglês

10.1148/90.1.46

1527-1315

JOHN F. ROCKETT, Thomas H. Johnson,

Intracranial Aneurysms: Treatment and Complications

The recent literature reports several cases of unilateral rete mirabile developing as a collateral of progressive vascular occlusive disease (5, 9). Minagi and Newton reported a congenital case associated with a hypoplastic internal carotid artery (6). The rete mirabile refers to an arterial anastomosis between the external craniofacial circulation and the cerebral circulation within a venous sinus (1, 2, 5, 6, 9). In man, connections between the internal maxillary artery and the internal carotid artery at the siphon correspond to the location of the rete mirabile caroticurn in lower animals (9). Most of the reports of the rete mirabile in the recent literature are of anastomoses occurring, not in the region of the sella turcica, but in branches of the external carotid such as the occipital and ascending pharyngeal arteries (5, 7, 9). The following case represents an angiographic demonstration of a bilateral arterial anastomosis between the branches of the external carotid artery and the internal carotid artery lateral to the sella turcica in the intracavernous portion of the carotid siphon. O. J., a 40-year-old male, suddenly became unconscious while drinking with friends. History from the family revealed a similar episode seven years previously which had been thought to be the result of an intracranial hemorrhage. A right internal carotid ligation had been performed, and the patient has had a left hemiparesis since that time. Physical examination at admission revealed a stuporous condition responding to painful stimuli. There was a left spastic hemiparesis and spontaneous right body movement. Brudzinski and Kernig signs were positive. Deep tendon reflexes were hyperactive bilaterally. No papilledema was present. A lumbar puncture revealed grossly bloody spinal fluid. No pressure was recorded. The clinical impression was subarachnoid hemorrhage, and the patient improved until the eighth hospital day when re-bleeding occurred. Lumbar puncture disclosed grossly bloody spinal fluid with an opening pressure of 300 mm of water. On the fourteenth hospital day, bilateral carotid angiography was performed. The patient remained comatose, and on the twenty-first hospital day he began to have seizures and died. No autopsy was obtained. Arteriographic Findings The left injection showed obstruction of the internal carotid at its origin (Fig. 1). A dense plexus of anastomotic arteries arising from the internal maxillary branch of the external carotid artery and connecting to the carotid siphon in the cavernous sinus area was demonstrated. The right-sided injection disclosed absence of the internal carotid artery which had been previously ligated (Fig. 2). Again a dense plexus of vessels originated from the internal maxillary branch of the external carotid and anastomosed to the carotid siphon where flow continued to the cerebral vasculature.