Intracranial aneurysm on a persistent primitive trigeminal artery. Case report

Ruptured Anterior Inferior Cerebellar Artery Aneurysm From a Persistent Trigeminal Artery: A Case Report

Persistent trigeminal artery (PTA) is the most common remnant of the primitive carotid-vertebrobasilar anastomoses, which typically form and obliterate during the early stages of human embryonic development. While PTA can be non-pathologic and is usually an incidental finding, it is also associated with various other vascular abnormalities, such as arteriovenous malformations and fistulae, but most commonly cerebral aneurysms. In these cases, aneurysms are usually reported in the anterior cerebral circulation or in the PTA trunk itself; to date, only one report exists of an associated aneurysm in the posterior circulation (basilar artery). These associated vascular pathologies are not only a source of morbidity and mortality but can also complicate subsequent endovascular treatment due to different flow patterns and increased vessel tortuosity. In this case report, we present the first reported case of PTA-associated aneurysm in the anterior inferior cerebellar artery and its resulting impact on the endovascular treatment of this aneurysm.

A persistent trigeminal artery demonstrates cerebrovascular embryologic development

Background

Cerebrovascular embryologic development is characterized by the presence of four well-described carotid-vertebrobasilar (VB) anastomoses. As the fetal hindbrain matures and the VB system develops, these connections involute, yet some may persist into adulthood. The persistent primitive trigeminal artery (PPTA) is the most common of these anastomoses. In this report, we describe a unique variant of the PPTA and a four-way division of the VB circulation.

Case Description

A female in her 70s presented with a Fisher Grade 4 subarachnoid hemorrhage. Catheter angiography revealed a fetal origin of the left posterior cerebral artery (PCA) giving rise to a left P2 aneurysm which was coiled. A PPTA arose from the left internal carotid artery and supplied the distal basilar artery (BA) including the superior cerebellar arteries bilaterally and the right but not left PCA. The mid-BA was atretic and the anterior inferior cerebellar artery-posterior inferior cerebellar artery complexes were fed solely from the right vertebral artery.

Conclusion

Our patient's cerebrovascular anatomy represents a unique variant of the PPTA not well described in the literature. This demonstrates how hemodynamic capture of the distal VB territory by a PPTA is sufficient to prevent fusion of the BA.

Clinical Importance of the Persistent Primitive Trigeminal Artery in Vascular Lesions and Its Role in Endovascular Treatment

The persistent primitive trigeminal artery (PPTA) extends from the internal carotid artery to the basilar artery between the origins of the anterior inferior cerebellar artery and superior cerebellar artery. PPTAs have complex anatomical characteristics. Salas and Saltzman classifications are most often used in PPTAs. The PPTA can play many roles in vascular lesions, including intracranial aneurysms, brain arteriovenous malformations, trigeminal artery-cavernous fistulas, Moyamoya disease, and large vessel occlusion. For these lesions, surgical treatment is difficult due to the deep location and complex anatomy of the PPTA, but endovascular treatment (EVT) has emerged as a good alternative. Currently, a complete review of the clinical importance of the PPTA in terms of its role in the development and EVT of vascular lesions is lacking. Therefore, we conducted a PubMed search, performed a review of the relevant extracted literature and cataloged our experience with PPTAs. By review, we found that a thorough understanding of the anatomical and angiographic features of this PPTA is of utmost importance when making therapeutic decisions for any of these pathological conditions.

Treatment of Aneurysms in Persistent Primitive Trigeminal Arteries with Stent-Assisted Coil Embolization

Objective

Persistent primitive trigeminal artery (PPTA) is a rare condition in which a fetal carotid-basilar anastomosis persists into adulthood. PPTA aneurysms often necessitate endovascular treatment and adjunctive techniques, such as stent- or balloon-assisted techniques, are sometimes selected. This case report describes two women in their sixties with unruptured right PPTA aneurysms who underwent stent-assisted coil embolization procedures, with consideration of the anatomical features in each case.

Case Presentations

One patient presented with an aneurysm at the bifurcation of the PPTA and the basilar artery (BA), which was classified as Saltzman type 1 with a hypoplastic vertebral artery (VA)-BA system. A stent was deployed from the BA to the PPTA to cover the neck of the aneurysm and coil embolization was performed. The second patient presented with an aneurysm at the bifurcation of the PPTA and the internal carotid artery (ICA), which was classified as Saltzman type 2 with a hypoplastic VA-BA system. A stent was deployed from the PPTA to the petrous segment of the ICA covering the neck of the aneurysm and coil embolization was performed. In both patients, the 1-year follow-up digital subtraction angiography (DSA) showed that the aneurysms had not recurred.

Conclusion

The PPTA aneurysms were successfully treated with stent-assisted coil embolization. The treatment strategy should be devised in accordance with both the lesion site and the PPTA variant.

Rare congenital anomalies of the internal carotid artery: anatomic and radiologic aspects of three cases and review of the literature

PURPOSE

Congenital anomaly of the internal carotid artery (ICA) is a rare entity. It is usually discovered incidentally by color doppler carotid sonography, angiography, computerized tomography (CT), or magnetic resonance imaging of the head and neck region taken for some other reasons. The aim of this study was to detect congenital ICA anomalies, to delineate existing collateral vessels and to find out its incidence.

METHODS

1847 patients' CT angiography images of the head and neck region taken between May 2013 and February 2018 were retrospectively evaluated for ICA anomalies.

RESULTS

We detected three cases (0.16%) with unilateral agenesis of ICA, bilateral agenesis of ICA and bilateral hypoplasia of ICA, respectively. Most patients are asymptomatic because of collateral cerebral circulation supplied by the communicating arteries of the circle of Willis, intercavernous anastomosis, communicating arteries from the external carotid artery, and by persistent embryologic arteries to the carotid artery territory.

CONCLUSION

Recognition of ICA anomalies has important implications during planned carotid or transsphenoidal surgery, in thromboembolic disease, and in the follow-up and detection of associated cerebral aneurysms.

Trigeminal Neuralgia Caused by a Persistent Primitive Trigeminal Artery Variant and Superior Cerebellar Artery

Trigeminal neuralgia is caused by compression of the trigeminal nerve by arteries or veins in the posterior fossa. A persistent primitive trigeminal artery variant (PPTAv) is an anomalous artery that may cause trigeminal neuralgia. A 65-year-old man presented with left facial pain. Brain magnetic resonance imaging revealed a PPTAv. Constructive interference in steady state showed that both the PPTAv and the superior cerebellar artery (SCA) compressed the trigeminal nerve. Thus, we performed microvascular decompression and the patient's symptoms improved. PPTAv is a rare anomaly in the posterior fossa that can cause trigeminal neuralgia. Dual compression of the trigeminal nerve by the SCA and PPTAv demonstrates that trigeminal neuralgia may originate from multiple sources. It is therefore important to check preoperative images to adequately treat trigeminal neuralgia.

Persistent trigeminal artery aneurysms: case report and systematic review

Background

The persistent trigeminal artery (PTA) is an adult carotid-basilar anastomosis with debated pathologic aspects, such as its association with brain aneurysms. True trigeminal artery aneurysms are rare vascular anomalies, reported in a few case reports.

Objective

To report our experience with a ruptured trigeminal artery aneurysm and to provide a systematic review of the literature in order to analyse potential links between the anatomic configuration of the PTA and PTA aneurysm (PTAA) type, and implications of each PTAA type for the diagnostic and therapeutic approach.

Methods

We reviewed the medical literature on trigeminal artery aneurysms according to the PRISMA guidelines. Population characteristics, aneurysms features, and PTA type and side were assessed.

Results

40 previously published cases of PTAAs were included in the analysis. The mean age of subjects was 55 years, with a strong female predominance (77%). Four PTAAs were accidentally discovered, while 16 caused compressive symptoms and 20 were ruptured. Successful endovascular treatment was performed in 62% of cases.

Conclusions

PTAAs are rare vascular anomalies, underdiagnosed in the presence of a trigemino-cavernous fistula. Parent vessel occlusion seems to be the best therapeutic option for ruptured or symptomatic unruptured PTAAs in Saltzman type II and III PTAs. Patency of the parent vessel is the main target in Saltzman type I PTA.

Coil embolisation of multiple cerebral aneurysms with lateral type I persistent primitive trigeminal artery: A case report and literature review

The primitive trigeminal artery is an anastomotic vessel of the carotid-basilar artery system that occurs only transiently during the embryonic period. Persistent primitive trigeminal artery occurs in approximately 0.1-0.6% of the population. Here, we report the case of a 60-year-old woman with Fisher II grade subarachnoid haemorrhage. Computed tomography angiography demonstrated a lateral, Saltzman type I persistent primitive trigeminal artery with three cerebral aneurysms, including one anterior communicating artery aneurysm, one suspicious right anterior choroidal artery aneurysm and one distal basilar artery aneurysm supplied by the persistent primitive trigeminal artery. All three aneurysms were treated with coil embolisation. At the 8-month follow-up, the anterior communicating artery aneurysm had a neck remnant, the other two aneurysms exhibited complete occlusion. Persistent primitive trigeminal artery with multiple cerebral aneurysms is extremely rare, and only seven cases of persistent primitive trigeminal artery with multiple cerebral aneurysms have previously been reported in publications that included information on treatment. Most aneurysms were treated by open surgery. This is the first report of coil embolisation treatment of multiple aneurysms in persistent primitive trigeminal artery patients with follow-up results, and provides relevant and valuable information about the persistent primitive trigeminal artery and the endovascular treatment of multiple aneurysms in persistent primitive trigeminal artery patients.

Endovascular treatment for unruptured aneurysm associated with persistent primitive trigeminal artery: a case report and literature review

The persistent primitive trigeminal artery (PPTA) is the most common carotid-basilar anastomosis, and the incidence of cerebral aneurysms associated with the PPTA is approximately 4%. Since PPTA aneurysms often have a wide neck and other vascular anomalies, endovascular treatment using an adjunctive technique is the current first-line therapy. Here, we report a case of PPTA aneurysm treated by coil embolization with a stent-assisted technique. A detailed evaluation of the size and course of all vessels and collateral flow, including the Allcock test and balloon test occlusion, is necessary when deciding on the treatment strategy.

Persistent Primitive Trigeminal Artery Associated With Anterior Communicating Artery Aneurysm and Hypoplastic Vertebral Artery

The persistent trigeminal artery is one of the presegmental arteries in the embryonic period; in some rare cases, it is associated with cerebral aneurysm but as a cause of subarachnoid hemorrhage (SAH) has not been described in the literature. We report a patient who presented a Fisher IV SAH associated with a ruptured intracranial aneurysm. The performed cerebral angiography demonstrated the presence of aneurysm in the anterior communicating artery associated to hypoplastic vertebral artery on the same side. We considered those finding coincidental. The coexistence of saccular aneurysm with anatomical variations in the intracranial vasculature is briefly discussed. It was managed by endovascular embolization. The patient returned to normal activities.

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.

Persistent Primitive Trigeminal Artery That Mimics Persistent Primitive Otic Artery on Cerebral Angiography

Persistent primitive trigeminal artery (PPTA) is the most common carotid-basilar anastomosis; on the other hand, persistent primitive otic artery (PPOA) is extremely rare. PPTA is often misdiagnosed as PPOA on cerebral angiography. We present a case of PPTA that mimicked PPOA on cerebral angiography. We further describe the utility of brain computed tomography angiography for differential diagnosis of PPTA from PPOA, together with a review of previous literature.

Communicating Segment Aneurysm of Internal Carotid Artery Associated with Saltzman's Type III Persistent Trigeminal Artery: A Case Report

Persistent trigeminal artery (PTA), also called primitive trigeminal artery, represents the most common embryonic remnant of fetal circulation in adulthood, (only after fetal pattern of posterior communicating artery [PComA]) with an estimated incidence of between 0.1% and 0.76%. The permanence of this fetal pattern constitutes an incidental finding in most cases, however, may be associated with aneurysms, arteriovenous malformations, trigeminal neuralgia, and other types of fetal circulation persistency. A patient with giant aneurysm in the communicating segment of the right internal carotid artery, associated with the presence of PTA and fetal pattern of PComA, also on the right side is reported.

Variant PTA Terminating in Cerebellar Artery, Associated with Multiple Aneurysms

Persistent trigeminal artery (PTA) is one of the remnant fetal anastomoses between the carotid artery and basilar artery. PTAs are classified according to angiographic appearance and various connection. Among them, those directly terminating in the cerebellar arteries are rare subtype. In addition, aneurysms of the PTA are unusual in the literature and have not previously accompanied this subtype of PTA connecting cerebellar artery. We present the first case of an aneurysm of the PTA which is directly terminating in the cerebellar arteries and combined with multiple aneurysms.

Successful recanalization for internal carotid artery occlusion with persistent primitive trigeminal artery manifesting only as ischemia of the posterior circulation

Background

Internal carotid artery (ICA) occlusion mainly manifests as ischemia of the anterior circulation. There are very few reports of ICA occlusion manifesting as only ischemia of the posterior circulation related to a fetal type posterior communicating artery or other arteries.

Case presentation

The authors experienced a case of ICA occlusion with persistent primitive trigeminal artery (PPTA) manifesting only as ischemia of the posterior circulation. In this case, the initial NIHSS score was high (35/42 points). Additionally, cross flow of the anterior communicating artery, ICA occlusion and basilar artery (BA) occlusion were represented on the initial head MRA. Therefore, our first impression was a presumptive diagnosis of BA occlusion. Prior head MRI/MRA performed for screening purposes, had incidentally demonstrated a right PPTA. Based on this understanding, we were able to determine the exact angioarchitectural mechanism of the ICA occlusion. Because of the presence of the PPTA, successful recanalization was accomplished expeditiously.

Conclusion

Although the presence of PPTA is rare and ICA occlusion patients with PPTA is even more unusual, if ICA occlusion and BA occlusion appear simultaneously on MRA, the presence of PPTA should be considered.

Double-balloon remodeling for coil embolization of a primitive trigeminal artery variant aneurysm. A case report

Here we describe the case of a patient with a wide-necked unruptured aneurysm arising at origin of a persistent primitive trigeminal artery (PTA) variant from the right internal carotid artery (ICA), supplying the territory of the right superior cerebellar artery and the anterior inferior cerebellar artery. To preserve the ICA and the PTA variant, coil embolization of the aneurysm was performed using a double-balloon remodeling technique (HyperForm™ and HyperGlide™ Occlusion Balloon Systems; ev3 Endovascular Inc., Irvine, CA, USA). The association of a PTA variant with an aneurysm is very rare. To our knowledge, this is the first description of the use of coil embolization using double-balloon remodeling to treat a PTA variant aneurysm. This technique permits complete embolization and reduces the risk of cerebral and cerebellar ischemia.

Multiple cerebral aneurysms with persistent primitive trigeminal artery

We report a patient with a persistent primitive trigeminal artery (PPTA) detected incidentally during cerebral angiography for the ruptured aneurysm. Cerebral angiography revealed a PPTA and eight anterior circulation cerebral aneurysms. Although cerebrovascular fragility, hemodynamic stress and hypertension are well known as etiologic factors for development of cerebral aneurysms, there is a known association of aneurysms with a PPTA, fetal carotid-basilar anastomosis. Furthermore, this case is rare from the viewpoint of aneurysm multiplicity.

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.

Trigeminal neuralgia caused by an anomalous posterior inferior cerebellar artery from the primitive trigeminal artery: case report

A 61-year-old woman presented with typical trigeminal neuralgia (TN), caused by an aberrant posterior inferior cerebellar artery (PICA) associated with the primitive trigeminal artery (PTA). Magnetic resonance angiography and digital subtraction angiography clearly showed an anomalous artery directly originating from the PTA and coursing into the PICA territory at the cerebellum. During microvascular decompression (MVD), we confirmed and decompressed vascular compression of the trigeminal nerve by this anomalous, PICA-variant type of PTA. The PTA did not conflict with the trigeminal nerve, and the anomalous PICA only compressed the caudolateral part of the trigeminal nerve, without the more common compression at its root entry zone. This case is informative due not only to its very unusual angioanatomical variation but also to its helpfulness for surgeons preparing a MVD for a TN associated with such a rare vascular anomaly.

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.

Basilar artery aneurysm at a persistent trigeminal artery junction. A case report and literature review

The trigeminal artery is an anastomosis between the embryonic precursors of the vertebrobasilar and carotid systems, and may persist into adult life. The association of the persistent primitive trigeminal artery (PTA) with cerebral aneurysm is well documented in the literature and, in general, aneurysms are located in the anterior circulation. We describe a patient who presented with a panencephalic Fisher III subarachnoid hemorrhage due to rupture of an intracranial aneurysm. Digital arteriography showed a saccular aneurysm in the middle third of the basilar artery, adjacent to the junction with a persistent trigeminal artery. She was submitted to endovascular treatment with embolization of the basilar artery aneurysm with coils. Aneurysms at the PTA junction with the basilar artery are rare. This paper describes a case of PTA associated with an aneurysm in the basilar artery at PTA junction and briefly reviews the literature.

Giant, thrombosed, sellar-suprasellar internal carotid artery aneurysm with persistent, primitive trigeminal artery causing hypopituitarism

A rare case of a giant, thrombosed, sellar-suprasellar paraclinoid internal carotid artery (ICA) aneurysm with persistent primitive trigeminal artery (PPTA) causing hypopituitarism that manifested as hypogonadism, hypothyroidism, and hypocortisolism is reported. There were no visual/neurological deficits, diabetes insipidus, or episodes of subarachnoid hemorrhage. The alteration in the flow dynamics of the circle of Willis due to the presence of PPTA may have been responsible for both the genesis of the giant aneurysm as well as for the induction of thrombogenesis within its lumen. As the digital subtraction angiogram showed complete thrombosis within the aneurysm and hormonal replacement therapy was effective in ensuring complete normalization of symptoms, the patient was unwilling to undergo surgical clipping of the aneurysm and removal of the suprasellar clot in an attempt to restore pituitary functions. Hypopituitarism recurred when the patient stopped her hormonal supplementation therapy after 7 years, and she again became symptom-free on restarting the therapy. To the best of the authors' knowledge, this represents the first reported case in the literature of hypopituitarism consequent to a giant, thrombosed, sellar-suprasellar ICA aneurysm with an associated PPTA on the side of the aneurysm.

Persistent Trigeminal Artery Variant: MR Angiographic Demonstration. A Report of Two Cases

A variant (PTAV) is the persistence after birth of the fetal carotid-basilar anastomosis between the internal carotid artery and a cerebellar artery. We describe two cases of a PTAV demonstrated on MR angiography. A comparison with a persistant trigeminal artery is made and an explanation of the extended Saltzman classification is given. These variants have only little clinical significance, but their recognition is crucial before surgical or interventional procedures or to understand paradoxical cerebellar lesions. MRA appears inferior to selective angiography in diagnosing these variants.

Persistent primitive trigeminal arteries (PTA) and its variant (PTAV): analysis of 103 cases detected in 16,415 cases of MRA over 3 years

INTRODUCTION

The primitive persistent trigeminal artery (PTA) is the most common carotid-basilar anastomosis, but because of its extremely low incidence, it is poorly understood. The purpose of this study is to clarify the features of PTA and its variants (PTAV) based on a large magnetic resonance angiography (MRA) series.

METHODS

MRA was performed on continuous 16,415 patients (8,610 males and 7,805 females) between October 2005 and September 2008 using two 1.5-T systems and one 1.0-T system. These all MRAs were evaluated by neuroradiologists.

RESULTS

The incidence of both PTA and PTAV was 0.68% (48 cases of PTA, 50 cases of PTAV, and five unclassified). Among them, 65 cases originated from the left internal carotid artery and 38 from the right. There were 44 cases of lateral type PTA and four cases of medial type. Hypoplasia of the basilar artery proximal to the union of PTA was recognized as follows: no hypoplasia in 12 cases, moderate hypoplasia in 22 cases, and severe hypoplasia in 13 cases. Distance from SCA and the union was an average of 6.7 mm. Four cases of pre- and postoperative cerebral aneurysms were recognized in 103 cases (3.9%).

CONCLUSION

We have identified details of both PTA/PTAV. The incidence of PTA was similar to previous studies, and the co-existence of cerebral aneurysm was also similar when compared to patients in the general population without PTA or PTAV.

Rupture of an aneurysm of the persistent trigeminal artery presenting as a carotid-cavernous sinus fistula

A 62-year-old Caucasian female presented with spontaneous right-sided eye pain, chemosis and ophthalmoloplegia. A right carotid-cavernous sinus fistula was discovered and successfully treated with transvenous introduction of Guglielmi detachable coils. In addition to complete fistula occlusion, follow-up angiography 6 weeks post-treatment demonstrated the presence of a patent persistent trigeminal artery previously hidden by the caliber of the carotid-cavernous sinus fistula. The spontaneous nature of the presentation and the proximity of the persistent trigeminal artery to the site of coil embolization suggest spontaneous rupture of a persistent trigeminal artery aneurysm as cause of the fistula. Current literature on this finding is discussed here, demonstrating that an aneurysm of the persistent trigeminal artery leading to carotid-cavernous sinus fistula formation is rare. Furthermore, the present case is the first report of its kind in world ophthalmology literature.

Two anatomical autopsy cases of direct communication between a persistent primitive trigeminal artery and an anterior inferior cerebellar artery

The persistent primitive trigeminal artery (PPTA) is the most common persistent carotid-basilar anastomosis. However, morphological findings of the PPTA based on the anatomical autopsy are very scarce. To understand the reason why such a variant artery develops, it is essential to examine the detailed morphology of the PPTA and developmental process of this artery. Here, we present two anatomical autopsy instances of the PPTA (cases 1 and 2). In the first case (78-year-old female; right side), the anterior inferior cerebellar artery (AICA) arose from the internal carotid artery passing medial to the abducens nerve. This artery gave off a small branch communicating to the basilar artery, passed lateral to the trigeminal nerve root, and continued backward to the dorsal surface of the cerebellum. Thus, in this case, the AICA is considered to be branched from the PPTA. In the second case (75-year-old female, left side), the PPTA branched from the internal carotid artery, and passed lateral to the abducens nerve, giving off an artery connecting with the AICA. These communicating arteries between the basilar artery and the AICA, recognized in cases 1 and 2, are considered to be the persistence of the primitive lateral basilovertebral anastomosis during the early embryological period. We propose that the primitive lateral basilovertebral anastomosis forms the arterial network around the trigeminal nerve root, and the AICA develops through this anastomosis.

Persistent trigeminal artery and associated vascular variations

Persistent trigeminal artery (PTA) is the most frequent type of persistent primitive carotid-basilar artery anastomoses. Persistent trigeminal artery is usually associated with small or absent posterior communicating artery (Pcom). It may also be associated with hypoplastic vertebral and basilar arteries. Patients may present with symptoms related to hypo-perfusion of posterior circulation or microembolization from carotid artery to posterior circulation. We are presenting a 60-year-old who had recurrent episodes of vertigo and parasthesia, in whom MR angiography revealed a medial, Saltzman type 1 PTA on the left with absent ipsilateral Pcom, duplicated ipsilateral superior cerebellar artery, hypoplastic A1 segment of contralateral anterior cerebral artery (ACA), azygous ACA and hypoplastic ipsilateral vertebral artery.

Persistent primitive trigeminal artery aneurysm associated with cerebellar hemangioblastoma. Case report

A 72-year-old man presented with a cerebellar vermian tumor manifesting as headaches and vertigo. Angiography disclosed a vascular tumor fed by the superior cerebellar artery and an aneurysm of a primitive trigeminal artery. The patient underwent right occipital craniotomy to remove the highly vascular tumor via an occipital transtentorial approach. Association of a cerebral aneurysm with a hemangioblastoma has been reported previously in only five cases. Only three aneurysms were located on the feeding artery. The aneurysm in this case was not on the feeding artery. Simple coincidence might account for this case.

[Persistent primitive trigeminal artery associated with brain cavernoma. Case report]

Among cases of embryonic carotid-basilar anastomosis which may persist after birth, persistent trigeminal artery is the most common. It has been associated with a wide variety of intracranial abnormalities. We are unaware of any other reported association with cavernoma. We report a young woman who experienced seizures following spontaneous abortion. A CT scan disclosed a right frontal hematoma. MRI revealed a cavernoma associated with a persistent trigeminal artery. The cavernoma was removed through a frontal approach. The aim of the present case is to report another type of lesion fortuitously associated with a persistent trigeminal artery.

Fusiform aneurysm of a persistent trigeminal artery

OBJECTIVE

Fusiform aneurysms of the persistent trigeminal artery are rare and endovascular treatment of these aneurysms has not been attempted previously. We describe a case of persistent trigeminal artery with a fusiform aneurysm in its middle third, managed using Guglielmi detachable coils (GDC).

CLINICAL PRESENTATION

A 50-year-old, diabetic and hypertensive patient presented with sudden onset headache and neck stiffness. On examination, she was conscious but disoriented, without cranial nerve or sensorimotor deficits. Four-vessel cerebral digital subtraction angiography revealed a fusiform aneurysm of the middle third of a persistent trigeminal artery on the left side with adult type posterior cerebral arteries.

INTERVENTION

Guglielmi detachable coils were used for occlusion of the persistent trigeminal artery.

RESULTS

The procedure was well tolerated but delayed ischemic neurological deficits developed due to vasospasm.

CONCLUSIONS

(1) In spite of angiographically documented independence of the anterior and posterior cerebral circulation, occlusion of a persistent trigeminal artery using endovascular techniques may result in posterior circulation stroke due to a number of factors, including occlusion of brainstem perforators taking origin from the persistent trigeminal artery or vasospasm. (2) The timing for endovascular intervention following aneurysmal rupture remains poorly defined.

Surgically treated aneurysm of the trunk of the persistent primitive trigeminal artery--case report

A 62-year-old man presented with a very rare cerebral aneurysm arising from the trunk of the persistent primitive trigeminal artery (PPTA) manifesting as subarachnoid hemorrhage. Angiography showed a saccular aneurysm at the curved mid-section of the trunk of the left PPTA of the adult type. The patient underwent surgery via the left subtemporal approach, and the aneurysm was successfully eliminated by clipping without sequelae. Aneurysm formation at this point was probably due to hemodynamic stress. The perforating arteries from the PPTA may be important in supply of the hindbrain, so PPTA patency should be preserved if possible.

Persistent carotid-vertebrobasilar anastomoses

The persistent carotid-vertebrobasilar anastomoses (PCVBA) can be explained by an interruption of the vertebrobasilar system (VBS) embryogenesis. We present two very rare cases of persistent anastomoses: a hypoglossal artery and a type I proatlantal artery, insisting on the angiographic criteria allowing differentiation. After a brief review of the embryogenesis of the VBS, we describe the different types of persistent anastomoses (hypoglossal, type I and II proatlantal, trigeminal and otic arteries). We will insist on the potential risks, not well-known, but typical of each anastomosis. PCVBA usually are incidental findings but imaging follow-up may be required since aneurysms may develop.

Persistent primitive trigeminal artery—cavernous sinus fistula with intracerebral hemorrhage: endovascular treatment using detachable coils in a transarterial double-catheter technique

✓ Intracerebral hemorrhage occurred in this 61-year-old woman with preexisting diplopia and proptosis. Results of angiography demonstrated a persistent primitive trigeminal artery (PPTA)—cavernous sinus fistula with cortical venous reflux. Two microcatheters were introduced transarterially through the PPTA into the two draining pathways in the cavernous sinus. Coils were delivered in both pathways simultaneously to prevent further venous overload on either path. The fistula was successfully occluded without complication while the PPTA was preserved. The authors describe this double-catheter technique for coil embolization of a fistula and review the literature concerning PPTA—cavernous sinus fistulas.

Intradural aneurysm arising from the posterior genu of the cavernous carotid artery mimicking a posterior communicating aneurysm: case report

OBJECTIVE AND IMPORTANCE

We present a rare case of an intradural aneurysm that arose from the posterior genu of the cavernous carotid artery and was diagnosed via angiography as originating from the internal carotid artery (ICA) at the level of the posterior communicating artery. Our review of the English-language literature found no other case of an intradural aneurysm that originated at the posterior genu of the cavernous ICA.

CLINICAL PRESENTATION

A 65-year-old woman presented with increasingly severe left retro-orbital headaches. Her family history included aneurysmal subarachnoid hemorrhage. Angiography revealed an 11-mm aneurysm, which was interpreted as arising from the left ICA at the level of the posterior communicating artery.

INTERVENTION

During a left pterional craniotomy, an aneurysm was identified underneath the oculomotor nerve; its neck seemed to arise from the posterior communicating artery segment. Despite clipping of the aneurysm attachment to the ICA and trapping of the posterior communicating segment, the aneurysm continued to fill. Further dissection revealed that the aneurysm's neck originated from the cavernous ICA. Placement of fenestrated clips around the oculomotor nerve successfully occluded the intradural portion of the aneurysm, as documented by an intraoperative angiogram.

CONCLUSION

We discuss this unique case to draw attention to the importance of the interpretation and adequacy of preoperative angiography, and we review pertinent vascular anatomy.

Trigeminal Neuralgia Associated with a Primitive Trigeminal Artery Variant: Case Report

OBJECTIVE AND IMPORTANCE

A variant type of the primitive trigeminal artery (PTA) is a rare anomalous vessel that originates from the internal carotid artery and directly supplies the territory of the anteroinferior cerebellar artery and/or the superior cerebellar artery. We report a case of trigeminal neuralgia associated with this PTA variant, and we discuss the characteristics of this vessel.

CLINICAL PRESENTATION

A 51-year-old woman presented with a 10-year history of left paroxysmal facial pain. Magnetic resonance angiography and cerebral angiography demonstrated that an aberrant vessel originating from the left internal carotid artery directly supplied the cerebellum, without a basilar artery anastomosis.

INTERVENTION

Surgical exploration was performed via a left retrosigmoid approach. A loop of the aberrant vessel, which entered the posterior fossa through the isolated dural foramen, was compressing the trigeminal nerve. This aberrant vessel was displaced medially from the nerve with a prosthesis, with care to avoid kinking and avulsion of the perforating arteries. The patient's neuralgia resolved postoperatively.

CONCLUSION

Although the PTA variant is frequently associated with intracranial aneurysms, it is extremely rare for the variant to lead to trigeminal neuralgia. During microvascular decompression surgery, surgeons should be careful to prevent injury of the perforating arteries arising from the PTA variant.

Congenital vascular malformations in childhood

Congenital vascular malformations are an important group of vascular anomalies that occur very early in the pregnancy. Most of these malformations occur between the third and the seventh weeks of the embryonic development. Malformations can affect the arteries, veins, capillaries, and venous sinuses, involving an isolated vessel or a part of the vascular system. There are malformations that affect the vessel size or course, and others that show pathology of the wall anatomy of the vessel. Magnetic resonance angiography (MRA) is improving the study conditions of this pathology. Treatment of most of the vascular malformations--some of them giving clinical symptoms during adulthood--still constitutes a challenge.