Persistent Trigeminal Artery in Endonasal Resection of Skull Base Tumors: A Systematic Review

Adding a chapter to the literature: A rare encounter of unilateral Moyamoya disease with ipsilateral persistent trigeminal artery

Background

The coexistence of persistent trigeminal artery (PTA) and Moyamoya disease (MMD) has been reported. If their pathogenesis is related and if PTA is protective or harmful in MMD remains unknown as these are rare cerebrovascular anomalies.

Case presentation

A 35-year-old woman with sudden global aphasia whose CT head and CT angiography of head and neck showed a hypodensity in the left posterior middle cerebral artery (MCA), a possible left proximal internal carotid artery occlusion, and a left PTA with hypoplasia of vertebral and basilar arteries. Digital subtraction angiography showed chronic MMD in the left MCA with extensive pial collateralization from anterior cerebral artery (ACA). The patient was initiated on single antiplatelet therapy and later she underwent direct bypass surgical intervention and rehabilitation.

Discussion

Our case report brings attention to the infrequent coexistence of ipsilateral MMD and PTA suggesting a potential congenital pathogenesis based on embryologic development and hemodynamics. Also, we propose a protective role of PTA in MMD in case of large anterior vessel occlusion. This case contributes to the scarce literature on the intriguing relationship between MMD and PTA.

Strategy for dealing with unfamiliar and thick vessels during microvascular decompression: A first case report of hemifacial spasm caused by a persistent primitive trigeminal artery

RATIONALE

A persistent primitive trigeminal artery (PPTA) is a rare embryonic cerebrovascular anomaly. Hemifacial spasm (HFS) refers to involuntary contractions of facial muscles caused by the compression of blood vessels against the root exit zone of the facial nerve. There have been no reported cases of PPTA causing neurovascular contact and HFS. Microvascular decompression surgery effectively treats HFS, but operating on strong PPTA vessels poses challenges. We aim to introduce a more efficient approach for overcomes these difficulties and facilitates surgery.

PATIENT CONCERNS

A 44-year-old male patient without any underlying medical conditions presented to our hospital with involuntary movements of the left side of his face accompanied by numbness in the left maxilla (V2 area).

DIAGNOSIS

Brain magnetic resonance imaging and magnetic resonance angiography showed that PPTA was in contact with the left facial nerve.

INTERVENTIONS AND OUTCOMES

Following a retro-sigmoid craniotomy, we attempted to interpose the facial nerve and the PPTA as an offender vessel, but the decompression was not sufficient. However, after transposing the vessel using the proximal Teflon transposition with interposition technique, the strength of the involuntary movements was reduced. Following surgery, there was no more lateral spreading response, and the patient symptoms improved.

LESSIONS

In cases where the vessel causing HFS is particularly strong and thick, the proximal Teflon transposition with interposition technique for transposition may be advantageous. This method could simplify and enhance the efficacy of microvascular decompression, without compromising the quality of surgical outcomes.

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

PURPOSE

The purpose of this study is to investigate the anatomical characteristics of persistent trigeminal artery (PTA) detected by computed tomography angiography (CTA) and magnetic resonance angiography (MRA), propose a modified classification and a novel grading system for basilar artery (BA).

METHODS

Patients who underwent head CTA or MRA in our hospital between August 2014 and August 2022 were reviewed retrospectively. The prevalence, sex, and course of PTA were evaluated. PTA types were modified based on Weon's classification. Type I to IV were similar to those in Weon's classification except the presence of intermed fetal-type posterior cerebral artery (IF-PCA). Type V was the same as that in Weon's classification. Type VI included subtypes of VIa (concomitant IF-PCA based on type I to IV) and VIb (other variants). BA was assessed based on a scale of 0 to 5 compared with PTA's caliber (0, BA aplasia; 1 and 2, BA non-dominant; 3, equilibrium; 4 and 5, BA dominant).

RESULTS

A total of 57 patients (0.06%) with PTA, including 36 females and 21 males, were detected in 94,487 patients. Six patients (10.5%) were medial type and 51 patients (89.5%) were lateral type. Thirty-seven patients (64.9%) were type I, 1 (1.8%) as type II, 13 (22.8%) as type III, 3 (5.3%) as type IV, 1 (1.8%) as type V, and 2 (3.5%) as type VI. For BA grading, 4 (7.0%), 21 (36.8%), 17 (29.8%), 6 (10.5%), 6 (10.5%), and 3 (5.3%) of the patients were grade 0, 1, 2, 3, 4, and 5, respectively. Fifteen patients (26.3%) had intracranial aneurysms. One cases (1.8%) had a fenestration of the PTA.

CONCLUSION

The prevalence of PTA in our study was lower than that in most previous reports. The modified PTA classification and BA grading system can be used to better understand the vascular structure of PTA patients.

New variant of persistent primitive trigeminal artery associated with duplicated basilar artery: a radiological case report

PURPOSE

This article reports a new variant of the persistent primitive trigeminal artery. This variant does not exist in Salas and Saltzman classifications.

METHODS

We analyzed CTA images of a 39-year-old male patient using RadiAnt. This work had clinical and research purposes.

RESULTS

A persistent primitive trigeminal artery arose from left internal carotid artery termination. Its course was atypical, superior, and lateral to the sella turcica. At its end, it joined a duplicated basilar artery. These morphological features are new compared to Salas and Saltzman's variants.

CONCLUSION

Anatomists, radiologists, and neurosurgeons must know this new variant. Angiographic analysis of this variant will keep the patient safe and perform the surgery. This new variant deserves to be considered in Salas and Saltzman classifications as a new type.

Anterior Transpetrosal Approach for Trigeminal Schwannoma with Persistent Primitive Trigeminal Artery: 2-Dimensional Operative Video

The surgical management of trigeminal schwannomas often requires complicated skull base approaches based on detailed anatomical understanding because of the involvement of multiple compartments of the trigeminal nerve from its root to the peripheral branches. When there is vital anatomical anomaly around the tumor, this can make the surgical management and anatomical understanding more difficult.1,2 This video demonstrates the microsurgical removal of a dumbbell-shaped trigeminal schwannoma via the anterior transpetrosal transtentorial approach in a patient with a persistent primitive trigeminal artery, the most common persistent embryonic carotid-vertebrobasilar anastomosis. A 32-yr-old woman presented with progressive facial sensory impairment, dizziness, and slight diplopia because of right abducens palsy. Neuroimaging revealed a right Meckel's cave tumor extending to both the middle and posterior cranial fossae and displacing the abducens nerve inferomedially. The persistent primitive trigeminal artery, which is an anomalous communication between the cavernous carotid and basilar arteries, was identified ventral to the tumor. While preserving most of the noninvaded trigeminal nerve, gross-total resection was achieved under direct visualization of the abducens nerve and persistent primitive trigeminal artery, piercing the dura of the posterior cavernous sinus and coursing medially along the clivus. The patient's facial sensory impairment and diplopia almost disappeared without new neurological deficits or tumor recurrence during the follow-up period of 1 yr. Three-dimensional reconstructed images demonstrated the anatomical relationship of the tumor, the persistent primitive trigeminal artery, and the extent of osseous drilling of the petrosectomy. Informed consent was obtained from the patient.

Prevalence and Clinical Implications of the Primitive Trigeminal Artery and its Variants: A Meta-Analysis

BACKGROUND

The primitive trigeminal artery (PTA) is the most common and the largest persistent carotid-basilar anastomosis. Primitive trigeminal artery variants (PTAVs) are anastomoses between the internal carotid artery and cerebellar arteries. These vessels pose a risk of hemorrhagic or ischemic complications during neurosurgical procedures in the parasellar and intrasellar regions. The aim of this study was to determine the prevalence of both PTA and PTAVs and their clinically important anatomic features.

METHODS

Major electronic databases were thoroughly searched for studies on PTA and PTAV. References in the included articles were also evaluated. Data regarding prevalence, laterality, origin, course patterns, and associated anomalies were extracted and pooled into a meta-analysis.

RESULTS

A total of 39 studies (110,866 patients) were included in the meta-analysis. The total pooled prevalence estimate of PTA and PTAVs combined was 0.4% (95% confidence interval [CI], 0.3-0.5). Individually, PTA was present in 0.3% of patients and PTAV in 0.2%. Both arteries most often originated from the C4 internal carotid artery and took a course lateral to the dorsum sellae. The anterior inferior cerebellar artery type was the predominant PTAV (72.1%). Basilar artery hypoplasia was found in 42.5% of patients with a PTA.

CONCLUSIONS

PTA and PTAVs are rare vessels, but they are clinically important because they can contribute to trigeminal neuralgia. Knowledge of the potential course of these arteries is essential in neuroradiology and neurosurgery, especially in minimally invasive procedures such as the endoscopic endonasal transsphenoidal approach to the pituitary gland and the percutaneous gasserian ganglion procedure.