Spontaneous disappearance of an intracranial small unruptured aneurysm on magnetic resonance angiography: Report of two cases

Yu Akimoto; Kiyoyuki Yanaka; Kuniyuki Onuma; Kazuhiro Nakamura; Nobuyuki Takahashi; Eiichi Ishikawa

doi:10.4103/ajns.AJNS_281_20

Asian Journal of Neurosurgery, Table of Contents

CC BY-NC-ND 4.0 · Asian J Neurosurg 2020; 15(04): 1055-1058
DOI: 10.4103/ajns.AJNS_281_20

Case Report

Spontaneous disappearance of an intracranial small unruptured aneurysm on magnetic resonance angiography: Report of two cases

Authors

Yu Akimoto

Department of Neurosurgery, Tsukuba Memorial Hospital, Tsukuba, Ibaraki
Kiyoyuki Yanaka

Department of Neurosurgery, Tsukuba Memorial Hospital, Tsukuba, Ibaraki
Kuniyuki Onuma

Department of Neurosurgery, Tsukuba Memorial Hospital, Tsukuba, Ibaraki
Kazuhiro Nakamura

Department of Neurosurgery, Tsukuba Memorial Hospital, Tsukuba, Ibaraki
Nobuyuki Takahashi

¹Department of Radiology, Tsukuba Memorial Hospital, Tsukuba, Ibaraki
Eiichi Ishikawa

²Department of Neurosurgery, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki

Abstract

Spontaneous radiographic disappearance of cerebral aneurysms is often observed under special conditions such as giant aneurysms. However, spontaneous disappearance of an unruptured and nongiant intracranial saccular aneurysms is rare. We describe two cases of this rare vascular phenomenon. The first patient is a 64-year-old female diagnosed with a small unruptured aneurysm arising from the distal anterior cerebral artery. Spontaneous disappearance of the aneurysm on magnetic resonance angiography (MRA) was observed 5 years after the initial diagnosis. Continuous imaging surveillance also revealed spontaneous reappearance of the aneurysm 2 years later. The second patient is a 57-year-old female harboring a small unruptured saccular aneurysm arising from the M1–M2 bifurcation of the middle cerebral artery. The aneurysm showed spontaneous disappearance on MRA 13 years after the initial diagnosis. These cases provide a new insight into this natural dynamic process even in cases of a small unruptured intracranial saccular aneurysm.

Key-words:

Spontaneous disappearance - thrombosis - unruptured cerebral aneurysm

Full Text

References

References
1 de Aguiar GB, Pagotto MV, Conti ML, Veiga JC. Spontaneous thrombosis of giant intracranial aneurysm and posterior cerebral artery followed by also spontaneous recanalization. Surg Neurol Int 2016;7:15.
2 Atkinson JL, Lane JI, Colbassani HJ, Llewellyn DM. Spontaneous thrombosis of posterior cerebral artery aneurysm with angiographic reappearance. Case report. J Neurosurg 1993;79:434-7.
3 Brownlee RD, Tranmer BI, Sevick RJ, Karmy G, Curry BJ. Spontaneous thrombosis of an unruptured anterior communicating artery aneurysm. An unusual cause of ischemic stroke. Stroke 1995;26:1945-9.
4 Choi CY, Han SR, Yee GT, Lee CH. Spontaneous regression of an unruptured and non-giant intracranial aneurysm. J Korean Neurosurg Soc 2012;52:243-5.
5 Yamada Y, Kinjo T, Ohki M, Kayama T. Spontaneous thrombosis of an unruptured internal carotid artery aneurysm: A case report. Surg Cereb Strok 2010;38:114-8.
6 Yokoya S, Hino A, Oka H. Rare spontaneous disappearance of intracranial aneurysm. World Neurosurg 2020;134:452-3.
7 Little AS, Garrett M, Germain R, Farhataziz N, Albuquerque FC, McDougall CG, et al. Evaluation of patients with spontaneous subarachnoid hemorrhage and negative angiography. Neurosurgery 2007;61:1139-50.
8 Kondo A, Yasuhara T, Sugiu K, Ohmoto T. Spontaneous thrombosis of a fusiform aneurysm arising from the distal posterior cerebral artery: Case report. No Shinkei Geka 2003;31:189-93.
9 Zhang YS, Wang S, Wang Y, Tian ZB, Liu J, Wang K, et al. Treatment for spontaneous intracranial dissecting aneurysms in childhood: A retrospective study of 26 cases. Front Neurol 2016;7:224.
10 Allen LM, Fowler AM, Walker C, Derdeyn CP, Nguyen BV, Hasso AN, et al. Retrospective review of cerebral mycotic aneurysms in 26 patients: Focus on treatment in strongly immunocompromised patients with a brief literature review. AJNR Am J Neuroradiol 2013;34:823-7.
11 Huang Y, Chen J, Wang J. Intracranial aneurysm disappeared after resection of a cardiac myxoma. Int J Clin Exp Med 2015;8:8214-7.
12 Morón F, Benndorf G, Akpek S, Dempsy R, Strother CM. Spontaneous thrombosis of a traumatic posterior cerebral artery aneurysm in a child. AJNR Am J Neuroradiol 2005;26:58-60.
13 Peltier J, Vinchon M, Soto-Ares G, Dhellemmes P. Disappearance of a middle cerebral artery aneurysm associated with Moyamoya syndrome after revascularization in a child: Case report. Childs Nerv Syst 2008;24:1483-7.
14 Hodozuka A, Sako K, Yonemasu Y, Suzuki N, Fujita T, Ohgami S. Spontaneous disappearance of aneurysm after total removal of accompanying intracranial arteriovenous malformation. Case report. Neurol Med Chir (Tokyo) 1991;31:966-71.
15 Pop R, Chibarro S, Manisor M, Proust F, Beaujeux R. Spontaneous thrombosis of a basilar tip aneurysm after ventriculoperitoneal shunting. BMJ Case Rep 2015;2015:bcr2015011841.
16 Whittle IR, Dorsch NW, Besser M. Spontaneous thrombosis in giant intracranial aneurysms. J Neurol Neurosurg Psychiatry 1982;45:1040-7.
17 Calviere L, Viguier A, Da Silva NA Jr., Cognard C, Larrue V. Unruptured intracranial aneurysm as a cause of cerebral ischemia. Clin Neurol Neurosurg 2011;113:28-33.