Incidental Findings of Persistent Primitive Trigeminal Artery on 3-Dimensional Time-of-Flight Magnetic Resonance Angiography at 3.0 T: An Analysis of 25 Cases

Posterior Petrous Meningioma Fed by a Branch of the Persistent Trigeminal Artery Terminating in the Anterior Inferior Cerebellar Artery

Persistent trigeminal artery (PTA) is the most common persistent carotid-basilar fetal anastomosis and terminates extremely rarely directly in the dominant hemispheric branch of the anterior inferior cerebellar artery (AICA). We present a case of a branch of this PTA variant (Saltzman type 3b) demonstrated as the feeding artery of a large posterior petrous meningioma, which was confirmed under direct vision during surgery through the extended retrosigmoid approach. Meticulous dissection from the tumor surface provided early identification of the feeding branch from the PTA and its bifurcation at the attachment of the posterior petrous surface adjacent to the jugular foramen enabled preservation of the terminal cortical branch of the cerebellar hemisphere. Meningioma in the posterior cranial fossa may recruit substantial supply from branches of the PTA terminating in the AICA. This PTA variant should be recognized during surgical resection of posterior fossa neoplasms to prevent ischemic complication of the AICA territory.

Cerebellar artery arising from the cavernous segment of the internal carotid artery and persistent trigeminal artery: a spectrum of incomplete longitudinal fusion

Background

The embryological relationship between cerebellar arteries originating directly from the cavernous segment of the internal carotid artery and persistent trigeminal artery is not well understood.

Purpose

To evaluate the incidence and pattern of cerebellar arteries originating from the internal carotid artery and persistent trigeminal artery, and to discuss their probable embryological relationship.

Material and Methods

We reviewed 5113 angiographic studies from 5093 patients at our institution over the last eight years, searching for patients with persistent trigeminal artery and cerebellar arteries originating from a cavernous segment of internal carotid artery (persistent trigeminal artery variant).

Results

Of the 5093 patients, 27 patients had persistent trigeminal artery or persistent trigeminal artery variant (0.53%). Twenty patients (6 men, 14 women; median age = 54 years) had persistent trigeminal artery (0.39%). Seven patients (2 men, 5 women, age range = 37–72 years; median age = 57 years) had a persistent trigeminal artery variant with persistent trigeminal artery terminating in a cerebellar artery without direct connection to the basilar artery (persistent trigeminal artery variant; 0.14%). The terminal branch of the persistent trigeminal artery variant was an anterior inferior carotid artery in five patients and a superior cerebellar artery in two patients. Of the seven patients having persistent trigeminal artery variant, four patients had another artery from the basilar artery to the anterior inferior carotid artery territory. In 6/20 patients with persistent trigeminal artery, there was an anterior inferior carotid artery arising from the persistent trigeminal artery. One of these patients showed another arterial branch from the basilar artery to the anterior inferior carotid artery territory.

Conclusion

Persistent trigeminal artery variant and cerebellar arteries originating from the persistent trigeminal artery are both believed to be a spectrum of incomplete fusion of the longitudinal neural arteries. Understanding the precise anatomy is important in diagnostic and therapeutic settings for related vascular disease.

Persistent trigeminal artery in a patient with posterior circulation stroke treated with rt-PA: case report

BACKGROUND

A persistent trigeminal artery (PTA) is a non-involuted embryonic vessel that connects the cavernous part of the internal carotid artery with the posterior circulation. In the adult it is associated with multiple pathological conditions including trigeminal neuralgia, ophthalmoplegia, hypopituitarism, intracavernous fistula, brain aneurysms and posterior circulation strokes. The latter may occur through steal phenomena or thrombosis in the anterior circulation. PTA associated vertebrobasilar hypoplasia has yet to be associated to TIA like events, however, in the reported case, that seems to be the case with reported vertigo being probably linked to vertebrobasilar insufficiency.

CASE REPORT

We present a case of an 82-year-old man with sudden onset neurological deficits, including left hemiparesis with crural predominance, vertical nystagmus, right internuclear ophthalmoplegia, dysarthria and dysmetria on the left arm. CT angiography disclosed basilar artery hypoplasia in the proximal two thirds and a persistent trigeminal artery. He was diagnosed with acute ischemic stroke. He was submitted to rt-PA with partial reversion of deficits.

CONCLUSION

The ischemic events related to PTA remain a rare cause of stroke with specific pathophysiological mechanisms and implications. They may occur through steal phenomena or thrombosis in the anterior circulation. Upon literature review, in the described case both mechanisms seem possible, however the transient episodes of vertigo could have been the first sign of vertebrobasilar insufficiency.

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.

Successful Microvascular Decompression For Trigeminal Neuralgia Secondary to a Persistent Trigeminal Artery

BACKGROUND AND IMPORTANCE

Persistent trigeminal artery (PTA) is a rare but important anatomic variant that contributes to trigeminal neuralgia (TN). Microvascular decompression (MVD) of the responsible vessel(s) away from the trigeminal nerve provides the most complete and durable relief from TN. The role and technique of MVD for TN associated with a PTA has not been fully defined in the literature. Furthermore, assessment of PTA anatomy intraoperatively with a microscope is challenging. We report the first 3-dimensional (3D) microscopic video and first intraoperative endoscopic video of a successful MVD of the trigeminal nerve in a patient who suffered TN from a tortuous, compressive PTA.

CLINICAL PRESENTATION

A 66-yr-old right-handed female presented with right facial pain in V2 and V3 distributions with a clinical picture of TN. Imaging demonstrated trigeminal nerve compression secondary to a PTA and MVD was performed with a 3D operative microscope and an endoscope. The PTA appeared to compress the nerve directly at the trigeminal porus and also had compressive superior cerebellar artery variant branches. The nerve was decompressed at all points of compression with Teflon pledgets along its entire cisternal length. Postoperatively, she is free with trigeminal pain episodes at 4-mo follow-up.

CONCLUSION

In cases of TN associated with a PTA, we recommend decompression along the entire length of the nerve wherever there is compression. Furthermore, we find both the operative microscope and particularly the endoscope useful to assess vascular anatomy intraoperatively.

Treatment of Large or Giant Cavernous Aneurysm Associated with Persistent Trigeminal Artery: Case Report and Review of Literature

BACKGROUND

Primitive trigeminal artery (PTA) is the most common anomaly of primitive carotid-basilar anastomosis and is associated with cerebrovascular anomalies, such as aneurysm. Large or giant cavernous aneurysm associated with PTA is rare, and the treatment strategies differ in comparison with large or giant aneurysm without PTA. In this article, we report an unusual case of a giant cavernous aneurysm associated with PTA and review treatment strategies for large or giant cavernous aneurysm associated with PTA.

CASE DESCRIPTION

A 38-year-old woman suffered from double vision. Magnetic resonance imaging revealed a mass lesion in the left cavernous sinus, and magnetic resonance angiography showed a giant aneurysm at the cavernous portion of the left internal carotid artery, associated with PTA. Coil embolization, distal to the PTA, was scheduled after high-flow bypass on the same day. Computed tomography scan showed no definite infarction after treatment. A 3-dimensional computed tomography showed disappearance of the aneurysm and good patency of bypass and PTA. The patient experienced improvements in symptoms and was discharged without neurologic deficits (modified Rankin Scale 0).

CONCLUSIONS

The treatment strategy for large or giant cavernous aneurysm associated with PTA is different from strategies used for large or giant cavernous aneurysm without PTA. Simple ligation of internal carotid artery is inadequate because the aneurysm is supplied through the PTA, from the vertebrobasilar system. Furthermore, the treatment strategy has to be revised according to whether the PTA can be occluded. Keeping in mind PTA preservation, an appropriate strategy should be selected.

Anatomical features and clinical relevance of a persistent trigeminal artery

Background:

Although persistent trigeminal artery (PTA) is uncommonly identified, knowledge of this structure is essential for clinicians who interpret cranial imaging, perform invasive studies of the cerebral vasculature, and operate this region.

Methods:

A review of the medical literature using standard search engines was performed to locate articles regarding the PTA, with special attention with anatomical descriptions.

Results:

Although anatomical reports of PTA anatomy are very scarce, those were analyzed to describe in detail the current knowledge about its anatomical relationships and variants. Additionally, the embryology, classification, clinical implications, and imaging modalities of this vessel are extensively discussed.

Conclusions:

Through a comprehensive review of isolated reports of the PTA, the clinician can better understand and treat patients with such an anatomical derailment.

Classification of persistent primitive trigeminal artery (PPTA): a reconsideration based on MRA

BACKGROUND

Persistent primitive trigeminal artery (PPTA) is the most common permanent carotid-basilar anastomosis. Magnetic resonance angiography (MRA) has become the primary non-invasive imaging technique for evaluation of cerebral vascular anatomy and can provide detailed 3D imaging of intracranial vessels.

PURPOSE

To evaluate the usefulness of MRA for the detection of PPTA and to re-classify its variations based on the embryologic types of PcomA and its relationship with the basilar artery and its branches.

MATERIAL AND METHODS

Of the total 7329 patients who underwent MRA at our institution from March 2008 through November 2010, we retrospectively analyzed the MRAs of 24 patients with a PPTA. Special attention was given to defining the relationship of the PPTA and the basilar artery with PcomA and to determine the site of origin, size, and course of the PPTA. The PPTA classification included five types based on their anatomic relationship to the neighboring arteries. Clinical features and associated vascular anomalies are also described.

RESULTS

Twenty-four (17 women and seven men, 34 ~ 81 years of age, mean age 59.67 years) of the 7329 patients had a PPTA (0.33 %). Eleven cases (45.8%) were classified as type 1, three (12.5%) as type 2, five (20.8%) as type 3, one (4.2%) as type 4, and four (16.7%) as type 5b. Fifteen PPTAs (62.5%) were located on the left side and nine were located (37.5%) on the right side. The basilar artery proximal to the insertion of the PPTA showed severe to moderate hypoplasia in 13 cases (54%). Nine intracranial artery aneurysms were detected in seven (29%) of the 24 study patients.

CONCLUSION

This study revealed five types of PPTA and necessitates an adjustment of the previous classification of PPTA on the basis of our MRA examinations. A PPTA should be considered by both the clinician and the radiologist who interpret MR angiography.