Persistent trigeminal artery variant and presumed ophthalmic artery simultaneously arising from the inferolateral trunk incidentally diagnosed by magnetic resonance angiography

doi:10.21203/rs.3.rs-3396663/v1

Download PDF

Research Article

Persistent trigeminal artery variant and presumed ophthalmic artery simultaneously arising from the inferolateral trunk incidentally diagnosed by magnetic resonance angiography

https://doi.org/10.21203/rs.3.rs-3396663/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 17 Nov, 2023

Read the published version in Surgical and Radiologic Anatomy →

You are reading this latest preprint version

Purpose

To describe a case of persistent trigeminal artery variant (PTAV) and presumed ophthalmic artery (OA) simultaneously arising from the inferolateral trunk (ILT).

Methods

A 53-year-old woman with an initial episode of convulsion underwent cranial magnetic resonance imaging (MRI) and MR angiography (MRA) of the intracranial region for the evaluation of brain and vascular lesions. The MR machine was a 3-T scanner.

Results

MRI revealed no pathological brain lesions. On MRA, the left anterior inferior cerebellar artery (AICA) arose from the cavernous segment of the internal carotid artery (ICA), indicative of the PTAV. The arising point was more distal than the usual point, and the presumed OA also arose simultaneously from the short common trunk, which was considered the ILT.

Conclusion

There are two types of PTA: lateral (usual) and medial (intrasellar) PTA. The lateral-type PTA and PTAV arise from the ICA of the distal precavernous-proximal cavernous segment and take a course similar to that of the posterior fossa. The medial type arises slightly more in the distal cavernous segment than in the lateral type. The OA rarely arises from the cavernous segment of the ICA and enters the orbit via the superior orbital fissure. The origin of this type of OA is considered to be the ILT. We herein report a case of a PTAV and presumed OA arising simultaneously from an ILT. No similar case has been reported in the relevant English-language literature.

Arterial variations

Carotid-vertebrobasilar anastomosis

Inferolateral trunk

Magnetic resonance angiography

Ophthalmic artery

Persistent trigeminal artery variant

The persistent trigeminal artery (PTA) and its variant (PTAV) are the most common congenital carotid-vertebrobasilar anastomoses. Using magnetic resonance angiography (MRA), the prevalence of the PTA, including the PTAV, was reported to be 0.68% [4]. The PTAV is the cerebellar artery arising from the distal precavernous-proximal cavernous segment of the internal carotid artery (ICA), and the anterior inferior cerebellar artery (AICA) is the most common [9]. The ophthalmic artery (OA) rarely arises from the cavernous segment of the ICA and enters the orbit via the superior orbital fissure (SOF). Its MRA prevalence is reported to be 0.42% per OA [10]. This type of OA arises from the inferolateral trunk (ILT) [3].

We herein report a case of an AICA-type PTAV and presumed OA simultaneously arising from an ILT. No similar cases have been reported in the relevant English-language literature.

A 53-year-old woman with an initial episode of convulsion underwent cranial magnetic resonance imaging (MRI) and MRA of the intracranial region for the evaluation of brain and vascular lesions. The magnetic resonance machine was a 3.0-Tesla scanner (Signa Architect; GE Healthcare, Milwaukee, WI, USA). MRA was performed using a standard three-dimensional time-of-flight technique. The imaging parameters were as follows: flip angle, 17°; repetition time, 23.0 s; echo time, 3.4 s; and slice thickness, 0.8 mm.

MRI revealed no pathological brain lesions. On MRA of the maximum intensity projection (MIP) image, the left AICA arose from the cavernous segment of the ICA, indicative of a PTAV. The arising point was more distal than the usual point, and an anteriorly running tiny artery also arose simultaneously with a short common trunk, which was considered an ILT (Fig. 1). After creating partial volume-rendering (VR) images of the left carotid system, the relationship between the ILT, PTAV, and the tiny artery became clear (Fig. 2). Reformatted source images of MRA at 5-mm thickness also clearly demonstrated these arterial variations (Fig. 3). On source images of MRA, a normally originating left OA was not observed, suggestive of origin variation. The artery entering the left SOF was not identified, probably because of the low spatial resolution of MRA. Thus, we diagnosed the anteriorly running tiny artery as the OA. A schematic illustration of this process is shown in Fig. 4.

No further examinations (e.g. computed tomography angiography or catheter angiography) were performed. Her clinical course was uneventful.

The PTA and PTAV are the most common carotid-vertebrobasilar anastomoses. The PTAV is the cerebellar artery arising from the distal precavernous or proximal cavernous segment of the ICA, without connection to the basilar artery (BA). The majority of PTAVs are of the AICA type [9]. Traditional PTA classifications were proposed by Saltzman [6], and Weon et al. [11] modified Saltzman’s classifications. However, while these classifications are useful from a hemodynamic perspective, they seem meaningless from an embryological perspective.

Salas et al. [5] classified PTA into two types according to its relationship to the abducens nerve: lateral and medial (intrasellar). It has been suggested that these two types of PTAs exhibit different embryonic development routes. The lateral type is the usual type, and approximately 90% of PTAs are classified as this type [2, 4, 9]. The origin of the PTA is closely related to the meningohypophyseal trunk (MHT). Thus, the MHT may be a remnant of the trigeminal artery. The PTAV takes a course similar to that of the lateral type, whereas the medial type arises more distally than the lateral type [7]. Our patient had an AICA-type PTAV arising from the lateral wall of the midportion of the cavernous ICA, more distal than the usual point, and had a lateral course. The arising point was regarded as the ILT.

There are several types of OA origin variation. The most frequently observed OA variation is the middle meningeal artery origin. This type of OA enters the orbit via the SOF. Its prevalence on MRA was reported to be 1.45% [10]. The OA rarely but occasionally arises from the cavernous segment of the ICA and enters the orbit via the SOF. This OA variation arises from the ILT and has been previously regarded as persistent dorsal OA [3, 10]. Recently, this anomalous origin of the OA was believed to be due to the persistence and enlargement of the lateral branch of the primitive maxillary artery [1]. True persistent dorsal OA enters the orbit via the optic canal. The OA may arise from MHT, which is extremely rare [8]. In our patient, a tiny artery arose from the ILT and had an anterior course. Unfortunately, the distal segment of the tiny artery could not be identified, probably because of the low spatial resolution of MRA. If this artery enters the SOF, it can be diagnosed as OA. On MRA source images, there was no OA normally arising from the supraclinoid ICA. Thus, we presumed that the tiny artery was an OA arising from the ILT simultaneously with the PTAV. To our knowledge, no similar cases have been reported in the relevant English-language literature.

However, the clinical significance of this arterial variation remains limited. If the cavernous segment of the left ICA is thrombosed, left cerebellar infarction and visual disturbance in the left eye may develop.

We encountered a case of AICA-type left PTAV that arose from the ILT simultaneously with a presumed OA. No similar case has been reported in the relevant English-language literature.

Author contributions AU carried out the study design and drafted the manuscript. AU and HM reviewed the manuscript critically, and have read and approved the final manuscript.

Funding The authors did not receive support from any organization for the submitted work.

Data availability Not applicable.

Conflict of interest The authors declare no competing interests.

Ethical approval and consent to participate All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Consent for publication The patient signed informed consent regarding publishing her data and figures.

Bertelli E, Regoli M, Bracco S (2017) An update on the variations of the orbital blood supply and hemodynamic. Surg Radiol Anat 39:485-496. doi: 10.1007/s00276-016-1776-9.
Huang W, Zhang Y, Zhuang Y, Shi Y, Feng Y (2023) An anatomical study of persistent trigeminal artery detected by computed tomography angiography and magnetic resonance angiography: proposal for a modified classification and a novel basilar artery grading system. Surg Radiol Anat 45:947-957. doi: 10.1007/s00276-023-03164-1.
Lasjaunias P, Moret J, Mink J (1977) The anatomy of the inferolateral trunk (ILT) of the internal carotid artery. Neuroradiology 13:215-220. doi: 10.1007/BF00344216.
O'uchi E, O'uchi T (2010) Persistent primitive trigeminal arteries (PTA) and its variant (PTAV): analysis of 103 cases detected in 16,415 cases of MRA over 3 years. Neuroradiology 52:1111-1119. doi: 10.1007/s00234-010-0669-6
Salas E, Ziyal IM, Sekhar LN, Wright DC (1998) Persistent trigeminal artery: an anatomic study. Neurosurgery 43:557-561; discussion 561-2. doi: 10.1097/00006123-199809000-00082
Saltzman GF (1959) Patent primitive trigeminal artery studied by cerebral angiography. Acta Radiol 51:329-336. doi: 10.3109/00016925909171103
Uchino A (2019) Carotid-vertebrobasilar anastomosis: magnetic resonance and computed tomographic angiographic demonstration. Jpn J Radiol 37:565-578. doi: 10.1007/s11604-019-00847-x
Uchino A, Ishihara S (2022) Ophthalmic artery arising from the presumed meningohypophyseal trunk of the cavernous internal carotid artery diagnosed by magnetic resonance angiography. Surg Radiol Anat 44:1025-1028. doi: 10.1007/s00276-022-02975-y.
Uchino A, Saito N, Okada Y, Kozawa E, Mizukoshi W, Inoue K, Takahashi M (2012) Persistent trigeminal artery and its variants on MR angiography. Surg Radiol Anat 34:271-276. doi: 10.1007/s00276-011-0848-0
Uchino A, Saito N, Takahashi M, Kozawa E, Mizukoshi W, Nakajima R, Okano N (2013) Persistent dorsal ophthalmic artery and ophthalmic artery arising from the middle meningeal artery diagnosed by MR angiography at 3 T. Surg Radiol Anat 35:775-782. doi: 10.1007/s00276-013-1085-5.
Weon YC, Choi SH, Hwang JC, Shin SH, Kwon WJ, Kang BS (2011) Classification of persistent primitive trigeminal artery (PPTA): a reconsideration based on MRA. Acta Radiol 52:1043-1051. doi: 10.1258/ar.2011.110191

No competing interests reported.

Download PDF

Journal Publication

published 17 Nov, 2023

Read the published version in Surgical and Radiologic Anatomy →

Editorial decision: Accepted
26 Oct, 2023
Reviews received at journal
04 Oct, 2023
Reviewers agreed at journal
03 Oct, 2023
Reviewers invited by journal
02 Oct, 2023
Editor assigned by journal
02 Oct, 2023
Submission checks completed at journal
02 Oct, 2023
First submitted to journal
28 Sep, 2023

You are reading this latest preprint version

Persistent trigeminal artery variant and presumed ophthalmic artery simultaneously arising from the inferolateral trunk incidentally diagnosed by magnetic resonance angiography

Status:

Journal Publication

Version 1

Abstract

Purpose

Methods

Results

Conclusion

Figures

Introduction

Case report

Discussion

Conclusions

Declarations

References

Additional Declarations

Status:

Journal Publication

Version 1