Spontaneous recession of a posterior cerebral artery aneurysm concurrent with carotid rete mirabile and moyamoya-pattern collateral vessels: a case report

Abstract

Background Carotid rete mirabile (RM) is a meshwork of multiple, freely intercommunicating arterioles that reconstitute the absent or hypoplastic segments of the internal carotid artery (ICA). Carotid RM has been reported to be associated with cerebrovascular diseases. However, it is rarely associated with moyamoya-pattern collateral vessels in the posterior cerebral artery (PCA) region and aneurysm. Case presentation A 39-year-old woman was admitted complaining of sudden-onset headache, nausea, and vomiting. Further investigation revealed subarachnoid hemorrhage (SAH), carotid RM, a moyamoya collateral pattern in the PCA region, and a pseudoaneurysm in the moyamoya-like vessels. The patient was treated conservatively, recovered well and was discharged 1 week later. Follow-up angiography showed that the aneurysm had disappeared. Conclusions As shown by the present case, we believe that carotid RM could occur in combination with moyamoya-pattern collateral vessels in the PCA region; aneurysms can occur in the moyamoya-like vascular network. Congenital etiology may be the reason for these combinations. Based on our approach in this case, aneurysm located in moyamoya-like vessels can disappear spontaneously after conservative treatment.

Cerebral Aneurysms with Internal Carotid Artery Agenesis: A Unique Case Similar to Moyamoya Disease and Literature Review

“…By contrast, an aneurysm with rete mirabile is occasionally located in a unique site, which is difficult to approach, as in the current case and in some cases. 4 , 12) Even if an aneurysm can be approached, the current artery cannot be easily saved by direct clipping or coil embolization. Therefore, these treatments are not used.…”

“…Indeed, there are some reports that the aneurysms located in collateral vessels could be disappeared by conservative therapy. 102 , 103) However, Kanamori et al 97) reported the importance of early surgical revascularization to prevent re-rupture of collateral artery aneurysms. Hence, we selected revascularization rather than conservative therapy for the present case.…”

“…In contrast, cerebral aneurysm rarely arises from a perforating artery. 4) In such a case, clipping or coiling may be challenging to perform due to localization of the aneurysm.…”

Transcallosal, transchoroidal clipping of a hypothalamic collateral vessel aneurysm in Moyamoya disease

“…MMD-associated collateral artery aneurysms are usually treated indirectly by surgical revascularization causing aneurysm obliteration due to an alteration of flow-related vessel dynamics [4,11,14,15,17,20]. The timing of bypass surgery after the initial bleeding remains unclear.…”

Clinical importance of the superficial temporal artery in neurovascular diseases: A PRISMA-compliant systematic review

“…In adult MMD, the combination of direct and indirect methods is beneficial as direct surgery can establish immediate blood flow, while indirect procedures can lead to a prolonged increase in perfusion [28,29]. In some patients, direct bypass can lead to spontaneous disappearance of the aneurysm in the collaterals [30]. Therefore, direct bypass plays a very important role in MMD treatment.…”