- Email: [email protected]
Rare Spontaneous Disappearance of Intracranial Aneurysm
Journal Pre-proof Spontaneous disappearance of intracranial aneurysm; A rare case report Shigeomi Yokoya, Akihiko Hino, Hideki Oka PII:
S1878-8750(19)32925-0
DOI:
https://doi.org/10.1016/j.wneu.2019.11.085
Reference:
WNEU 13754
To appear in:
World Neurosurgery
Received Date: 11 September 2019 Revised Date:
13 November 2019
Accepted Date: 14 November 2019
Please cite this article as: Yokoya S, Hino A, Oka H, Spontaneous disappearance of intracranial aneurysm; A rare case report, World Neurosurgery (2019), doi: https://doi.org/10.1016/ j.wneu.2019.11.085. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Elsevier Inc. All rights reserved.
Spontaneous disappearance of intracranial aneurysm; A rare case report
Authors: Shigeomi Yokoya, Akihiko Hino, and Hideki Oka.
Affiliations: Department of Neurosurgery, Saiseikai Shiga Hospital, Imperial Gift Foundation Inc., Ritto, Shiga, Japan.
Corresponding author: Shigeomi Yokoya, MD, PhD Oh-hashi 2-4-1, Ritto, Shiga 520-3046, Japan Telephone number: +81-77-552-1221 Fax number: +81-77-553-8259 E-mail address: [email protected]
Highest academic degrees for all authors: Shigeomi Yokoya, M.D., Hideki Oka, M.D., Akihiko Hino, M.D.
Key Words: Spontaneous disappearance Unruptured clinoid segment aneurysm
Highlights; Intracranial aneurysm disappearance
Yokoya
Abstract An unruptured anterior circulation, non-giant saccular cerebral aneurysm (located at the
clinoid segment [C3] of the internal carotid artery [ICA], and growing into the carotid cave), was
detected at a medical checkup, and diagnosed from subsequent examinations (Figure 1). The
aneurysm was observed and followed up with radiological examinations. An examination performed
12 years after diagnosis revealed the disappearance of the aneurysm (Figure 2). This observation
should be kept in mind, that it is possible for an unruptured aneurysm to undergo spontaneous
thrombosis without any intervention.
Highlights; intracranial aneurysm disappearance
1
Yokoya
Text A 53-year-old female, with a history of uterine polyps at the age of 34, and an ovarian cyst
at the age of 35, both requiring surgeries, underwent a screening examination for a brain disease.
Magnetic resonance angiography (MRA) suggested an unruptured cerebral aneurysm (Figure 1A and
B). She underwent a digital subtraction angiography (DSA) that revealed a clinoid segment (C3)
aneurysm, that was growing into the carotid cave (Figure 1C). The aneurysm was observed and
followed up every year with an MRA. For 11 years, the aneurysm remained unchanged on the MRA
examinations. However, 12 years after the initial diagnosis, the aneurysm disappeared on the MRA
and DSA examinations (Figure 2).
Spontaneous aneurysm disappearance has been reported to occur under special circumstances: post subarachnoid hemorrhage aneurysms,1 giant/ fusiform aneurysms,2 dissecting aneurysm,3 an aneurysm with a large volume to neck ratio,4 an aneurysm with a small inclination angle to the parent artery,5 an aneurysm that changes shape and angle after the implantation of a ventriculoperitoneal shunt,6 aneurysms associated with the removal of accompanying arteriovenous malformations,7 and aneurysms associated with Moyamoya disease after revascularization.8
However, spontaneous thrombosis of an unruptured non-giant, anterior circulation
aneurysm is extremely rare. This case demonstrated the disappearance of an anterior circulation
non-giant aneurysm without any intervention. To the best of our knowledge, only one similar case
2
Yokoya
has been reported previously, which described the disappearance of a C3 aneurysm via natural means.9
The mechanism behind spontaneous aneurysm thrombosis is unknown, but turbulent flow
within an aneurysm is a well-known fact, which could account for complete or partial thrombosis of
the aneurysm together with endothelial injury. The thrombus can also resolve over time, which
suggests the need for continuous imaging surveillance. It is known that C3 aneurysms are less likely
to rupture, but long term follow-up is mandatory to determine its course.
Acknowledgements
Funding sources: This research did not receive any specific grant from funding agencies in the public, commercial, or
not-for-profit sectors.
Disclosure and conflicts of interest; The authors declare that we have no conflict of interest.
Ethical approval; The publication of this case report was approved by the Ethics Committee of Saiseikai Shiga
3
Yokoya
Hospital (Permission number: 364)
4
Yokoya
Figure captions: Figure 1
(A and B) Initial magnetic resonance angiography (MRA) images showing an aneurysm of the left
internal carotid artery. (C) A digital subtraction angiography (DSA) showing a 2.96 × 4.08mm left
clinoid segment (C3) saccular aneurysm.
Figure 2
(A and B) Magnetic resonance angiography (MRA) images twelve years after the initial examination,
showing the disappearance of the aneurysm. (C) A cerebral digital subtraction angiography (DSA)
demonstrating the resolution of the C3 aneurysm.
5
Yokoya
References: 1.
Little AS, Garrett M, Germain R, et al. Evaluation of patients with spontaneous
subarachnoid hemorrhage and negative angiography. Neurosurgery. 2007;61:1139-1150; discussion
1150-1131.
2.
Moron F, Benndorf G, Akpek S, et al. Spontaneous thrombosis of a traumatic posterior
cerebral artery aneurysm in a child. AJNR American journal of neuroradiology. 2005;26:58-60.
3.
Kondo A, Yasuhara T, Sugiu K, et al. Spontaneous thrombosis of a fusiform aneurysm
arising from the distal posterior cerebral artery: case report [In Japanese]. No shinkei geka
Neurological surgery. 2003;31:189-193.
4.
Ohta H, Sakai N, Nagata I, et al. Spontaneous total thrombosis of distal superior cerebellar
artery aneurysm. Acta neurochirurgica. 2001;143:837-842; discussion 842-833.
5.
Choi CY, Han SR, Yee GT, et al. Spontaneous regression of an unruptured and non-giant
intracranial aneurysm. J Korean Neurosurg Soc. 2012;52:243-245.
6.
Pop R, Chibarro S, Manisor M, et al. Spontaneous thrombosis of a basilar tip aneurysm
after ventriculoperitoneal shunting. BMJ case reports. 2015;. 2015:bcr2015011841
7.
Hodozuka A, Sako K, Yonemasu Y, et al. Spontaneous disappearance of aneurysm after
total removal of accompanying intracranial arteriovenous malformation. Case report [In Japanese].
Neurologia medico-chirurgica. 1991;31:966-971.
6
Yokoya
8.
Peltier J, Vinchon M, Soto-Ares G, et al. Disappearance of a middle cerebral artery
aneurysm associated with Moyamoya syndrome after revascularization in a child: case report.
Child's nervous system : ChNS : official journal of the International Society for Pediatric
Neurosurgery. 2008;24:1483-1487.
9.
Yamada Y, Kinjo T, Ohki M, et al. Spontaneous thrombosis of an unruptured internal
carotid artery aneurysm: A case report [In Japanese]. Surg Cereb Stroke (Jpn). 2010;38:114-118.
7
Abbreviations list: C3: Clinoid segment of internal carotid artery DSA: Digital subtraction angiography ICA: Internal carotid artery MRA: Magnetic resonance angiography
S1878-8750(19)32925-0
DOI:
https://doi.org/10.1016/j.wneu.2019.11.085
Reference:
WNEU 13754
To appear in:
World Neurosurgery
Received Date: 11 September 2019 Revised Date:
13 November 2019
Accepted Date: 14 November 2019
Please cite this article as: Yokoya S, Hino A, Oka H, Spontaneous disappearance of intracranial aneurysm; A rare case report, World Neurosurgery (2019), doi: https://doi.org/10.1016/ j.wneu.2019.11.085. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Elsevier Inc. All rights reserved.
Spontaneous disappearance of intracranial aneurysm; A rare case report
Authors: Shigeomi Yokoya, Akihiko Hino, and Hideki Oka.
Affiliations: Department of Neurosurgery, Saiseikai Shiga Hospital, Imperial Gift Foundation Inc., Ritto, Shiga, Japan.
Corresponding author: Shigeomi Yokoya, MD, PhD Oh-hashi 2-4-1, Ritto, Shiga 520-3046, Japan Telephone number: +81-77-552-1221 Fax number: +81-77-553-8259 E-mail address: [email protected]
Highest academic degrees for all authors: Shigeomi Yokoya, M.D., Hideki Oka, M.D., Akihiko Hino, M.D.
Key Words: Spontaneous disappearance Unruptured clinoid segment aneurysm
Highlights; Intracranial aneurysm disappearance
Yokoya
Abstract An unruptured anterior circulation, non-giant saccular cerebral aneurysm (located at the
clinoid segment [C3] of the internal carotid artery [ICA], and growing into the carotid cave), was
detected at a medical checkup, and diagnosed from subsequent examinations (Figure 1). The
aneurysm was observed and followed up with radiological examinations. An examination performed
12 years after diagnosis revealed the disappearance of the aneurysm (Figure 2). This observation
should be kept in mind, that it is possible for an unruptured aneurysm to undergo spontaneous
thrombosis without any intervention.
Highlights; intracranial aneurysm disappearance
1
Yokoya
Text A 53-year-old female, with a history of uterine polyps at the age of 34, and an ovarian cyst
at the age of 35, both requiring surgeries, underwent a screening examination for a brain disease.
Magnetic resonance angiography (MRA) suggested an unruptured cerebral aneurysm (Figure 1A and
B). She underwent a digital subtraction angiography (DSA) that revealed a clinoid segment (C3)
aneurysm, that was growing into the carotid cave (Figure 1C). The aneurysm was observed and
followed up every year with an MRA. For 11 years, the aneurysm remained unchanged on the MRA
examinations. However, 12 years after the initial diagnosis, the aneurysm disappeared on the MRA
and DSA examinations (Figure 2).
Spontaneous aneurysm disappearance has been reported to occur under special circumstances: post subarachnoid hemorrhage aneurysms,1 giant/ fusiform aneurysms,2 dissecting aneurysm,3 an aneurysm with a large volume to neck ratio,4 an aneurysm with a small inclination angle to the parent artery,5 an aneurysm that changes shape and angle after the implantation of a ventriculoperitoneal shunt,6 aneurysms associated with the removal of accompanying arteriovenous malformations,7 and aneurysms associated with Moyamoya disease after revascularization.8
However, spontaneous thrombosis of an unruptured non-giant, anterior circulation
aneurysm is extremely rare. This case demonstrated the disappearance of an anterior circulation
non-giant aneurysm without any intervention. To the best of our knowledge, only one similar case
2
Yokoya
has been reported previously, which described the disappearance of a C3 aneurysm via natural means.9
The mechanism behind spontaneous aneurysm thrombosis is unknown, but turbulent flow
within an aneurysm is a well-known fact, which could account for complete or partial thrombosis of
the aneurysm together with endothelial injury. The thrombus can also resolve over time, which
suggests the need for continuous imaging surveillance. It is known that C3 aneurysms are less likely
to rupture, but long term follow-up is mandatory to determine its course.
Acknowledgements
Funding sources: This research did not receive any specific grant from funding agencies in the public, commercial, or
not-for-profit sectors.
Disclosure and conflicts of interest; The authors declare that we have no conflict of interest.
Ethical approval; The publication of this case report was approved by the Ethics Committee of Saiseikai Shiga
3
Yokoya
Hospital (Permission number: 364)
4
Yokoya
Figure captions: Figure 1
(A and B) Initial magnetic resonance angiography (MRA) images showing an aneurysm of the left
internal carotid artery. (C) A digital subtraction angiography (DSA) showing a 2.96 × 4.08mm left
clinoid segment (C3) saccular aneurysm.
Figure 2
(A and B) Magnetic resonance angiography (MRA) images twelve years after the initial examination,
showing the disappearance of the aneurysm. (C) A cerebral digital subtraction angiography (DSA)
demonstrating the resolution of the C3 aneurysm.
5
Yokoya
References: 1.
Little AS, Garrett M, Germain R, et al. Evaluation of patients with spontaneous
subarachnoid hemorrhage and negative angiography. Neurosurgery. 2007;61:1139-1150; discussion
1150-1131.
2.
Moron F, Benndorf G, Akpek S, et al. Spontaneous thrombosis of a traumatic posterior
cerebral artery aneurysm in a child. AJNR American journal of neuroradiology. 2005;26:58-60.
3.
Kondo A, Yasuhara T, Sugiu K, et al. Spontaneous thrombosis of a fusiform aneurysm
arising from the distal posterior cerebral artery: case report [In Japanese]. No shinkei geka
Neurological surgery. 2003;31:189-193.
4.
Ohta H, Sakai N, Nagata I, et al. Spontaneous total thrombosis of distal superior cerebellar
artery aneurysm. Acta neurochirurgica. 2001;143:837-842; discussion 842-833.
5.
Choi CY, Han SR, Yee GT, et al. Spontaneous regression of an unruptured and non-giant
intracranial aneurysm. J Korean Neurosurg Soc. 2012;52:243-245.
6.
Pop R, Chibarro S, Manisor M, et al. Spontaneous thrombosis of a basilar tip aneurysm
after ventriculoperitoneal shunting. BMJ case reports. 2015;. 2015:bcr2015011841
7.
Hodozuka A, Sako K, Yonemasu Y, et al. Spontaneous disappearance of aneurysm after
total removal of accompanying intracranial arteriovenous malformation. Case report [In Japanese].
Neurologia medico-chirurgica. 1991;31:966-971.
6
Yokoya
8.
Peltier J, Vinchon M, Soto-Ares G, et al. Disappearance of a middle cerebral artery
aneurysm associated with Moyamoya syndrome after revascularization in a child: case report.
Child's nervous system : ChNS : official journal of the International Society for Pediatric
Neurosurgery. 2008;24:1483-1487.
9.
Yamada Y, Kinjo T, Ohki M, et al. Spontaneous thrombosis of an unruptured internal
carotid artery aneurysm: A case report [In Japanese]. Surg Cereb Stroke (Jpn). 2010;38:114-118.
7
Abbreviations list: C3: Clinoid segment of internal carotid artery DSA: Digital subtraction angiography ICA: Internal carotid artery MRA: Magnetic resonance angiography