Persistent primitive olfactory artery aneurysm

Embryology of the anterior communicating artery complex: implications on possible adult variants

The anterior cerebral artery (ACA) and the anterior communicating artery (AComA) are important arteries of the telencephalon and are prominent location for cerebral aneurysms. Their embryological development is closely linked, and explains the possible variants seen in adults. In this paper, we present details related to the development of these two arteries, focusing on some variants such as the infra-optic course of the ACA, the unpaired ACA, and the persistent primitive olfactory artery.

Coil embolization of subarachnoid hemorrhage with ruptured persistent primitive olfactory artery aneurysm

Background:

Persistent primitive olfactory artery (PPOA) is a rare anomaly of the anterior cerebral artery. We experienced a rare case of subarachnoid hemorrhage caused by a ruptured saccular aneurysm of PPOA.

Case Description:

A 72-year-old man was transported to our hospital with sudden headache. On examination, World Federation of Neurological Surgeons scale was Grade I, and computed tomography of the head showed subarachnoid hemorrhage in Fisher Group 3. Cerebral angiography showed left PPOA and a 4-mm saccular aneurysm at the hairpin turn. No other abnormalities causing bleeding were observed. Based on these findings, subarachnoid hemorrhage due to a ruptured PPOA aneurysm was diagnosed. As the patient had a ventilatory defect due to emphysema, direct approach to the lesion would have been difficult and an endovascular surgery was performed. Three coils were inserted into the aneurysm, and complete occlusion was achieved. Cerebral vasospasm was not observed, and the patient was discharged 1 month after surgery without any neurologic deficit.

Conclusion:

Most aneurysms of the PPOA are formed at the hairpin turn, as observed in our patient; therefore, a hemodynamic mechanism may be involved in the etiology. To the best of our knowledge, there is no report on treatment using intra-aneurysmal coil embolization, indicating that ours was the first case. As the long-term outcome of intra-aneurysmal coil embolization for PPOA aneurysm is unknown, careful follow-up will be necessary in the future.

Persistent primitive olfactory artery associated with early bifurcated accessory anterior cerebral artery

Five types of persistent primitive olfactory artery (PPOA), a rare variation of the proximal anterior cerebral artery (ACA), have been reported. Type 1 is most common, generally following an extreme anteroinferior course and taking a hairpin turn before continuing to the distal A2 segment of the ACA. Triple ACAs are a common variation of the A2 segment of the ACA, and a centrally located artery is called an "accessory ACA" or "median artery of the corpus callosum". This artery usually does not bifurcate or else bifurcates distally and continues to the pericallosal artery. We herein report a 74-year-old woman with type 1 PPOA and early bifurcated accessory ACA, an extremely rare combination of ACA variations, that was diagnosed using magnetic resonance angiography.

A1 Segment Unruptured Aneurysm of Persistent Primitive Olfactory Artery Coexisted with Accessory Middle Cerebral Artery

A persistent primitive olfactory artery (PPOA) is a rare anomaly of anterior cerebral artery (ACA), which generally arises from the internal carotid artery (ICA), runs along the olfactory tract, and makes a hairpin bend to supply the territory of the distal ACA. PPOA is also associated with cerebral aneurysms. An accessory MCA is a variant of the middle cerebral artery (MCA) that arises from either the proximal or distal portion of the A1 segment of the ACA, which runs parallel to the course of the MCA and supplies some of the MCA territory. We experienced a rare case of coexistence of PPOA with an unruptured aneurysm and accessory MCA. Three-dimensional computed tomographic angiography (3D-CTA) has an excellent picture of the spatial relationship of the surrounding bony and vascular structure.

Persistent primitive olfactory artery without a hairpin turn

Persistent primitive olfactory artery (POA) is a relatively rare variation of the proximal anterior cerebral artery (ACA) that generally follows an extreme anteroinferior course and takes a hairpin turn before continuing to the A2 segment of the ACA. There are other extremely rare variations, such as (1) that continuing to the ethmoidal artery without a hairpin turn, (2) that continuing to both ethmoidal artery and distal ACA with a hairpin turn, and (3) that continuing to the accessory middle cerebral artery with a hairpin turn. We herein report a case of persistent POA without a hairpin turn continuing to the A3 segment of the ACA. We propose calling this new type of persistent POA Type 5.

Aneurysm of the A1 Segment of the Anterior Cerebral Artery Associated with the Persistent Primitive Olfactory Artery

BACKGROUND

The persistent primitive artery constitutes the anterior cerebral artery proper. When the persistent primitive artery keeps its embryologic course along the olfactory bulb, it is called the persistent primitive olfactory artery (PPOA).

CASE DESCRIPTION

A 69-year-old man presented with an incidentally discovered unruptured aneurysm at the origin of the PPOA. The PPOA originated at the A1 segment of the anterior cerebral artery, coursed anteromedially along the olfactory tract, made a hairpin turn posterosuperior to the midline, and formed the callosomarginal branch of the anterior cerebral artery. The anomalous artery was interpreted as a PPOA (type 3). Type 3 PPOA associated with an unruptured aneurysm is rare.

CONCLUSIONS

There is a high incidence of aneurysms associated with a PPOA. Follow-up studies are necessary in the present case to monitor for the development of another aneurysm at the hairpin bend.

Persistent primitive olfactory artery: CT angiographic diagnosis and literature review for classification and clinical significance

OBJECTIVES

The aim of this study was to investigate the incidence of a persistent primitive olfactory artery (POA) and to review the literatures focusing on the classification and clinical significance of this variant.

DESIGN

To identify cases with persistent POA, we reviewed the records of computed tomography (CT) angiography performed on 3,067 patients in our institution from January 1, 2011 to August 31, 2013. Literatures on the incidence and classification of a persistent POA were reviewed.

RESULTS

Among these patients, eight were diagnosed with a persistent POA (five men, three women, aged 44-82 years), an incidence of 0.26 %. Six persistent POAs terminated as a distal anterior cerebral artery (ACA) and two as a distal middle cerebral artery. Previous studies applied similar definitions for the classification of persistent POA; however, there has been confusion on the definition of variant 2.

CONCLUSION

In our institution, the incidence of persistent POA seen on CT angiography was 0.26 %. An artery with its embryological course along the olfactory bulb should be classified as a persistent POA and differentiated from dural artery from ACA.

Persistent primitive olfactory artery in Serbian population

The continuation of the cranial branch of the primitive internal carotid artery is called the primitive olfactory artery (POℓA). It takes this name according to the fact that it is mainly concerned with supplying the developing nasal region. We reported two new cases of the persistent POℓA (PPOℓA) in Serbian population after retrospective analysis of digital images of 200 fetal and 269 adult cases. This PPOℓA originated from the precommunicating part (A1) of the right anterior cerebral artery, coursed along the olfactory tract, and turned on the medial cerebral hemisphere in both male adults. Some vascular variations (fenestration of the A1 and the median artery of the corpus callosum) were associated with this persistent vessel. According to the fact that we did not find aneurysm in our previous and two recent cases, we are of the opinion that PPOℓA is usually asymptomatic in Serbian population.

New variant of persistent primitive olfactory artery associated with a ruptured aneurysm

The authors present the case of a 78-year-old man who presented with a subarachnoid hemorrhage due to rupture of an aneurysm at the origin of the persistent primitive olfactory artery (PPOA). Interestingly, the PPOA was originating from the A1 segment of the anterior cerebral artery and coursed anteromedially along the olfactory tract. Moreover, the PPOA in this case had 2 branches: the branch making a hairpin turn and supplying the distal part of the anterior cerebral artery territory (Type 1), and the branch extending to the cribriform plate to supply the nasal cavity (Type 2). To the best of the authors' knowledge, this is a new variant (Type 3) of PPOA associated with a ruptured aneurysm. The clinical implications of this case are discussed in terms of the embryological aspects.

Diagnosis of persistent primitive olfactory artery using computed tomography angiography

Persistent primitive olfactory artery (PPOA) is a rare anomaly of the anterior cerebral artery. We present one case of PPOA incidentally diagnosed with the aid of computed tomography (CT) angiography. A 24-year-old woman was admitted to our hospital after sudden onset of vertigo. Three-dimensional CT angiography revealed an anomalous artery arising from the terminal portion of the right internal carotid artery. The proximal portion of the anomalous artery coursed anteromedially and made a hairpin turn posterosuperior to the midline. PPOA may be overlooked because of its rarity, but CT angiography can be useful in detecting this rare vascular anomaly. Follow-up study is necessary in our case to confirm whether an aneurysm occurs on the PPOA.