Congenital agenesis/aplasia of the internal carotid arteries: MRA and SPECT findings

Congenital absence of the bilateral internal carotid artery: a review of the associated (ab)normalities from a newborn status to the eighth decade of life

PURPOSE

Due to the fact that the internal carotid artery (ICA) is responsible for nourishing two thirds of the brain volume, our aim was to inspect the morphofunctional consequences of the bilateral lack of this artery.

METHODS

In order to examine this condition, we referred to both the library archive of our Faculty of Medicine and electronic databases of anatomical and clinical reports that included the following keywords: "absence," "aplasia," or "agenesis" in combination with "internal carotid artery," "common carotid artery," or only "carotid artery."

RESULT

We found 60 recorded cases of the bilateral ICA absence in the subjects of newborn status to the eighth decade of life, which had been discovered in 20 countries. The following ten parameters were described: the embryological base, terminology, history, incidence, general data, differential diagnosis, collateral circulation, the associated vascular aplasia and/or other variants, pathophysiology, and the importance in praxis.

CONCLUSION

This review noted all the cases of the bilateral ICA aplasia published for the past 104 years. Although there were 11.6% of cases of the associated cerebral aneurysms and 1-4 cases of 16 other diseases, approximately one quarter of the cases was without any pathology.

Congenital hypoplasia of the Internal Carotid Artery

A newborn presented at 14 hrs of age with right sided clonic seizures and shrill cry. Magnetic Resonance Imaging of the brain showed left cerebral hemiatrophy with cystic changes in left fronto-parietal lobe and parasylvian region. The Magnetic Resonance Angiography revealed hypoplasia of left supraclinoid Internal Carotid Artery and hypoplasia and irregularity of vessel wall affecting the left Middle Cerebral Artery. Such an early presentation of this rare disorder has not been reported previously. Recognition of this anomaly has important implications during carotid and trans-sphenoidal surgery, in thromboembolic disease, and in the surveillance and detection of associated cerebral aneurysms.

Absence of the right internal carotid artery found during autopsy of a severe burn case

Since absence and hypoplasia of the internal carotid arteries are known to be rare anomalies but often presents no symptoms, most such cases are accidentally revealed by a carotid angiogram performed for patients with cerebrovascular disease. We herein report the autopsy findings for a 65-year-old man who burned to death in an apartment fire. Medicolegal autopsy revealed absence of the right internal carotid artery. However, malformation of the brain was not observed. Generally, it is difficult to decide the manner of death in an autopsy case of death due to burn, however, it is possible that the manner of death was natural death in this case.

Congenital absence or hypoplasia of the carotid artery: radioclinical issues

PURPOSE

Congenital anomaly of the carotid artery is a rare abnormality. It is usually discovered incidentally by color Doppler carotid sonography, angiography, computed tomography (CT), or magnetic resonance imaging (MRI) of the head and neck taken for some other reason. Most patients are not symptomatic because of sufficient cerebral circulation supplied to the defective area by the communicating arteries of the circle of Willis, intercavernous anastomosis, communicating arteries from external carotid artery, and by persistent embryologic arteries to the carotid artery territory. However, sometimes, this anatomic variation may eventually lead to some clinical signs and symptoms in particular circumstances in the head and neck of which surgeons are unaware. A retrospective study was designed to emphasize the characteristic radiologic and clinical picture in patients with the congenital absence (agenesis and aplasia) or hypoplasia of the carotid artery, to delineate the associated abnormalities and existing collateral vessels, and to find out its incidence.

MATERIAL AND METHODS

Five thousand one hundred cerebral MRI and/or catheter angiograms performed between February 1988 and March 2002 were reviewed for carotid artery abnormality.

RESULTS

Seven patients with congenital absence or hypoplasia (4 of these patients were presented with hypoplasia of internal carotid artery [ICA], 3 with absence of ICA) of ICA were identified (0.13%). The radiologic and clinical study of 5 patients with unilateral (3 of these patients were presented with hypoplasia and 2 with absence of ICA) and 2 patients with bilateral (1 was presented with absence of ICA, whereas the other was hypoplasia) congenital abnormality with absence or hypoplasia of ICA demonstrate that those patients are usually asymptomatic and they are diagnosed incidentally.

CONCLUSION

It has been concluded that the combined use of magnetic resonance angiography and CT scanning of the skull base may disclose small but patent ICA. Collateral vessels seem to be usual in such cases, but they may be prominent in cases of acquired vascular occlusion, or increased hemodynamic pressure in dysplastic changes in collateral arteries are known causes of aneurysms. The main vascular supply for the brain in patients with congenitally small (hypoplasia) or absent (agenesis or aplasia) ICA is the vertebrobasilar system in bilateral cases. However, contralateral carotid vessel is the dominant arterial supply for unilateral cases, which has to be borne in mind in surgical interventions to the involved side.

Congenital Horner's syndrome resulting from agenesis of the internal carotid artery

OBJECTIVE

To report a patient with agenesis of the right internal carotid artery associated with ipsilateral, congenital Homer's syndrome.

DESIGN

Case report.

METHODS

A 30-year-old woman, with a past history of migraine headaches, underwent neuro-ophthalmologic and neuroradiologic evaluation for transient visual obscurations and congenital Horner's syndrome.

RESULTS

A right, third-order neuron Horner's syndrome was confirmed with 1% hydroxyamphetamine topical drops. Cranial magnetic resonance imaging revealed an absent right internal carotid artery flow void, computed tomography demonstrated absence of the right carotid canal, and cerebral angiography confirmed absence of the right internal carotid artery. No atheromatous lesions were found and the results of coagulation studies were normal.

CONCLUSIONS

Agenesis of the internal carotid artery is a rare cause of congenital Horner's syndrome. The cause of transient visual blurring in the current patient remains unproven.

Aberrant common carotid artery encountered during free jejunal graft repair of oesophageal stricture

The origin and course of the carotid arterial system in the superior mediastinum and neck are remarkably constant. Although variations are rare, they can have important implications in certain clinical problems. In this report, a patient underwent free jejunal graft repair of a cervical oesophageal stricture caused by radiotherapy for a post-cricoid carcinoma. The common carotid artery on the side of the surgical approach was found to cross the midline to the other side of the neck, and created difficulties both with the procedure and future management. This has not been previously reported.

Unilateral anomalous left common carotid artery; a case report

An anomaly of the left common carotid artery was observed in a Japanese male cadaver during an anatomy class at the Saitama Medical School in 1995. The superior thyroid, lingual and facial arteries arose from the common carotid artery, and the posterior auricular, maxillary and superficial temporal arteries arose from the common carotid artery by a common trunk. The occipital and ascending pharyngeal arteries arose from the internal carotid artery. The left carotid body (glomus caroticum) was observed to be slightly below the lingual artery, behind the common carotid artery, and it was located at the level of the intervertebral disk between C2 and C3 or at the same level as the right carotid body. The carotid body was richly innervated by a branch of the glossopharyngeal nerve and by a plexus of sympathetic fibers from the vagus and glossopharyngeal nerves. We assumed that the artery above the level of the carotid body was the internal carotid artery; there was no specific external carotid artery and all branches of the external carotid artery arose from the internal carotid artery.