User Tools

Site Tools


Multiple intracranial aneurysm

Multiple intracranial aneurysms (MIAs) are two or more intracranial aneurysms that exist in the cranium.


Among the patients with intracranial aneurysms, the incidence of multiple aneurysms was 33.5%. Multiple aneurysms were much more common in women, with a female to male ratio of 5:1 for all patients and 11:1 for patients with three or more aneurysms.

It occurs especially in postmenopausal women.

This phenomenon may be related to the loss of estrogen protection. MIA patients are associated with IgE syndrome 1).

MIA accounts for about a third of the patients with subarachnoid hemorrhage 2).

The Beijing Tiantan Hospital reported that MIA cases account for 8.1% (123/1511) of all treated cases of aneurysms in the same period 3).


To date, the genesis and pathogenesis of MIA are not clearly elucidated.

Patients with atrial myxoma and cerebral vascular malformations could also be suffering from MIA 4) 5).

MIA coexists with various vascular malformations 6).

Hypertension and bad habits, such as drinking and, smoking, can induce multiple aneurysms. MIA detection has gradually become widespread because of the popularity of cerebral angiography.


Common locations for multiple aneurysms were the posterior communicating artery (22%), middle cerebral artery (21.5%), anterior communicating artery (12%), and ophthalmic artery (11%). However, locations with the highest probability of rupture were the anterior communicating artery (62%), posterior inferior cerebellar artery (50%), and basilar artery summit (50%). The middle cerebral artery was the least likely site for rupture. In contrast to previous studies, in the series of Neels et al. irregularity of contour was more important than size in identifying the site of rupture. Using a simple algorithm, it was possible to identify the site of aneurysm rupture in 97.5% of cases 7).

MR-VWI may be useful for identifying the rupture site in patients with spontaneous SAH and multiple cerebral aneurysms 8).

Diagnosis of the offending aneurysm

Determination of the offending aneurysm and initially undergoing occlusion are necessary. Different indices have been established by imaging observation to distinguish ruptured aneurysms from unruptured aneurysms. Baumann 9) observed that larger aneurysms and anterior communicating aneurysms often rupture. The size ratio (SR) value of the ruptured aneurysms is significantly larger than unruptured aneurysms. This result is based on the ratio of aneurysms and aneurysmal arteries by Rahman 10).

The increased bottleneck factor and the height–width ratio are considered inherent characteristics of the ruptured aneurysms in the control of ruptured and unruptured aneurysms by Hoh 11).

Aneurysm was also identified according to its 12) morphology and near vascular response


A combination of surgical operation and endovascular treatment, as well as simple surgical treatment, has been recommended for MIA treatment 13) 14).

Correct localization of the rupture aneurysm based on a comprehensive diagnosis is key to MIA treatment.

The decision regarding the type of surgery to be used (either one-stage or multiple-stage surgery) as an operation strategy for multiple aneurysms and the location of bilateral multiple aneurysms (either along the bilateral approach or the unilateral approach) are still not clearly elucidated.

All the aneurysms should be treated in one session whenever possible to protect the patient from rebleeding 15).

Single-stage coil embolization of multiple unruptured intracranial aneurysms is technically feasible. The time required for such procedures and the rate of complications observed seem acceptable 16) 17).

Although a number of reports are available on occlusion of bilateral aneurysms in the middle cerebral artery bifurcation along the unilateral approach 18) 19) , according to Oshiro’s study 20) , contralateral middle cerebral artery bifurcation is difficult to observe along the unilateral pterional approach when the contralateral M1 segment is >14 mm.


Takeuchi S, Wada K, Otani N, Nawashiro H: Multiple intracranial aneurysms associated with hyper-IgE syndrome. Intern Med 51: 515-516, 2012
Ellamushi HE, Grieve JP, Jäger HR, Kitchen ND: Risk factors for the formation of multiple intracranial aneurysms. J Neurosurg 4: 728-732, 2001
Sun JJ, Zhao JZ, Wang S, Zhao YL, Wang ZY: Surgical treatment of multiple intracranial aneurysms. Beijing Da Xue Xue Bao 36: 272-275, 2004
Gorge KJ, Rennie A, Saxena A: Multiple cerebral aneurysms secondary to cardiac myxoma. Br J Neurosurg 26: 409-411, 2012
5) , 14)
James Ling A, D’Urso PS, Madan A: Simultaneous microsurgical and endovascular management of multiple cerebral aneurysms in acute subarachnoid haemorrhage. Clin Neurosci 13: 784-788, 2006
Li M, Lin N, Wu J, Liang J, He W: Multiple intracranial aneurysms associated with multiple dural arteriovenous fistulas and cerebral arteriovenous malformation. World Neurosurg 77: 398, 2012
Nehls DG, Flom RA, Carter LP, Spetzler RF. Multiple intracranial aneurysms: determining the site of rupture. J Neurosurg. 1985 Sep;63(3):342-8. PubMed PMID: 4020459.
Kondo R, Yamaki T, Mouri W, Sato S, Saito S, Nagahata M, Nagahata S, Kayama T. [Magnetic resonance vessel wall imaging reveals rupture site in subarachnoid hemorrhage with multiple cerebral aneurysms]. No Shinkei Geka. 2014 Dec;42(12):1147-50. doi: 10.11477/mf.1436200050. Japanese. PubMed PMID: 25433063.
Baumann F, Khan N, Yonekawa Y: Patient and aneurysm characteristics in multiple intracranial aneurysms. Acta Neurochir Suppl 103: 19-28, 2008
Rahman M, Smietana J, Hauck E, Hoh B, Hopkins N, Siddiqui A, Levy EI, Meng H, Mocco J: Size ratio correlates with intracranial aneurysm rupture status: A prospective study. Stroke 41: 916- 920, 2010
Hoh BL, Sistrom CL, Firment CS, Fautheree GL, Velat GJ, Whiting JH, Reavey-Cantwell JF, Lewis SB: Bottleneck factor and height-width ratio: Association with ruptured aneurysms in patients with multiple cerebral aneurysms. Neurosurgery 61: 716-723, 2007
12) , 13)
Chung J, Shin YS: Multiple intracranial aneurysms treated by multiple treatment modalities. Neurosurgery 69: E1030- 1032, 2011
Wang G, Feng WF, Zhang GZ, Li WG, Li MZ, He XY, Peng SW, Qi ST. [Diagnosis and treatment of multiple intracranial aneurysms]. Nan Fang Yi Ke Da Xue Xue Bao. 2015 Jan;35(1):121-4. Chinese. PubMed PMID: 25613624.
Cho YD, Ahn JH, Jung SC, Kim CH, Cho WS, Kang HS, Kim JE, Han MH. Single-Stage Coil Embolization of Multiple Intracranial Aneurysms: Technical Feasibility and Clinical Outcomes. Clin Neuroradiol. 2014 Dec 17. [Epub ahead of print] PubMed PMID: 25516149.
Shen X, Xu T, Ding X, Wang W, Liu Z, Qin H. Multiple intracranial aneurysms: endovascular treatment and complications. Interv Neuroradiol. 2014 Jul-Aug;20(4):442-7. doi: 10.15274/NRJ-2014-10037. Epub 2014 Aug 28. PubMed PMID: 25207907; PubMed Central PMCID: PMC4187440.
Hopf NJ, Stadie A, Reisch R: Surgical management of bilateral middle cerebral artery aneurysms via a unilateral supraorbital key-hole craniotomy. Minim Invasive Neurosurg 52: 126-131, 2009
Martellotta N, Gigante N, Toscano S, Maddalena GF, Tripodi M, Settembrini G,Stroscio C, Distefano G, Citro E: Unilateral supraorbital keyhole approach in patients with middle cerebral artery (M1-M2 segment) symmetrical aneurysms. Minim Invasive Neurosurg 46: 228-230, 2003
Oshiro EM, Rini DA, Tamargo RJ: Contralateral approaches to bilateral cerebral aneurysms: A microsurgical anatomical study. J Neurosurg 87: 163-169, 1997
multiple_intracranial_aneurysm.txt · Last modified: 2015/03/31 10:50 (external edit)