Dolichoectasia of the internal carotid artery terminus, posterior communicating artery, and posterior cerebral artery: The embryonic caudal ramus internal carotid segmental vulnerability legacy.

Dolichoectasia of the distal internal carotid artery, posterior communication artery (PCoA) and posterior cerebral artery is an extremely rare abnormality. Dolichoectasia of the internal carotid artery, PCoA and the P1 segment of posterior cerebral artery can be postulated its pathogenesis by the embryological perspective basis from caudal ramus of the internal carotid artery terminus. The pathogenesis and treatment strategy are not well established. We reviewed and proposed embryological perspective, pathogenesis, clinical setting, radiological findings and management of this rare malformation.

Endovascular intervention of acute ischemic stroke due to occlusion of fetal posterior cerebral artery.

A fetal posterior cerebral artery (FPCA) is an anatomic variant in which the posterior cerebral artery is an embryological derivative of the internal carotid artery. Although most cases of ischemic strokes in patients with FPCAs involve embolic infarcts, emergent large vessel occlusion of a FPCA is extremely rare. We present two cases of successful endovascular intervention for emergent occlusion of a FPCA, one of which is only the second reported case of a mechanical thrombectomy of a FPCA. We review the embryology of FPCA, the controversy regarding its association with cerebral infarcts, and various approaches used in the treatment of such occlusive lesions.

Coiling of a recurrent broad-necked posterior communicating aneurysm incorporating a fetal cerebral artery: A technical case report.

We describe a case of a right broad-necked posterior communicating artery (PcomA) aneurysm with a fetal posterior cerebral artery (PCA) incorporated in the aneurysm neck. We performed waffle cone stent-assisted coiling and achieved almost complete occlusion of the aneurysm. At 18-month follow-up angiography, the aneurysm was recanalized and further coiling was needed. The same waffle cone method of coiling might be expected to produce the same unsatisfactory results on follow-up, so we decided to use retrograde stent navigation and placement through the anterior communicating artery (AcomA) from the contralateral internal carotid artery (ICA) to the ipsilateral ICA and fetal PCA. The stent delivery microcatheter from the contralateral ICA could not be introduced in the AcomA. So 2 mg nimodipine was infused through the stent delivery microcatheter to the AcomA and the stent delivery microcatheter was passed through the AcomA easily and could be navigated to the ipsilateral A1, ICA, and to the fetal PCA. With this additional stent, the aneurysm was completely separated from the fetal PCA and ICA. Further coiling could be performed safely through the microcatheter in the ipsilateral ICA. The patient had stable aneurysm occlusion at the six-month follow up.

Variation of the posterior cerebral artery and its embryological explanation: a cadaveric study.

The posterior cerebral arteries are paired vessels that usually originate from the basilar artery at the level of the pontomesencephalic fissure and are joined by the posterior communicating artery to close the posterior portion of the Circle of Willis (circulus arteriosus cerebri). There is a considerable variation in the presence of the arterial segments of the circle of Willis. In the fetal type posterior cerebral artery there is an embryonic derivation of this vessel from the internal carotid artery. The irrigation of the posterior cerebral artery territory is thus completely dependent on the internal carotid artery. The term fetal-type posterior cerebral artery is used whether or not there is a communication with the basilar artery through a small pre-communicating segment (P1) of the posterior cerebral artery. This study deals with the variations of the posterior part of the circle of Willis, especially the origin of the posterior cerebral artery (PCA). The size of the posterior communicating artery (PComA) in comparison with the size of posterior cerebral artery is one of the principal differences between the fetal and adult forms of the circulus arteriosus cerebri. There are three configurations regarding posterior cerebral and posterior communicating arteries according to compare their diameters.

Normal subtypes of the posterior part of the cerebral arterial circle in human fetuses.

BACKGROUND: Although centuries of the human CAC research are behind us, still there is a stimulus for the authors to describe something new or to add to the "archive" of already known facts about its angioarchitecture. METHODS: With normal configurations of the posterior part of the CAC in early prenatal status, 172 brains of human fetuses from the 13th to the 24th week were used in the purpose of investigation. Brain arteries were injected and microdissected using a surgical microscope. RESULTS: According to diameter values of vascular components in the posterior part of the CAC, 6 basic types and the corresponding number of their subtypes are formed. Incidences of bilateral transitory (18.6%), fetal (9.3%), and adult (33.1%) types, as well bilateral asymmetric types (fetal-transitory in 5.8%, adult-transitory in 14.5%, and adult-fetal in 18.6% of cases), proved that dominant configuration of posterior part had not been present in the period from the fourth to the sixth gestational month. CONCLUSION: The finding of normal subtypes of the posterior part of the CAC, as well as the absence of some subtypes, is a challenge for future studies of the posterior arterial pattern within vascular abnormalities or diseases.

Morphometry of posterior cerebral artery: embryological and clinical significance.

Posterior cerebral artery, terminal branch of basilar artery joins the posterior communicating artery to help complete the circulus arteriosus cerebri in human beings. A study of 89 formalin-fixed brain specimen of either sex and of Indian origin has showed that the mean length and diameter of the posterior cerebral artery was 6.75 +/- 1.482 mm and 1.7 +/- 0.7 mm respectively. Anomalous origin of the posterior cerebral artery was the only variation found during the present study. The incidence of occurrence of the particular variant was 2.2%. The variation did not have any sex or side predilection.

Segmental agenesis of the internal carotid artery distal to the posterior communicating artery leading to the definition of a new embryologic segment.

We report a case of segmental agenesis of the right internal carotid artery (ICA) in a 53-year-old woman, associated with a saccular aneurysm of the left anterior cerebral artery (A1 segment) presenting with a right hemispheric transient ischemic attack. The agenetic segment was located distal to the origin of the posterior communicating artery (PComA), as documented both angiographically and by direct surgical inspection. This observation suggests the existence of a previously unrecognized embryologic segment of the ICA, located between the PComA origin and the terminal bifurcation of the ICA into the anterior and middle cerebral arteries.

Changes in blood vessels in fetuses 4 to 9 months intrauterine life old by postmortem angiography method.

We monitored changes in caliber, position and branching of blood vessels in fetuses of 4 - 9 months of intrauterine life. By precise dissection we prepared starting parts of common carotid artery and internal jugular vein in 40 cadaver fetuses. The vessels were injected with Telebrix and subjected to postmortem angiography at the Institute of Radiology Clinics Center in Sarajevo. Thereafter, arteries obtained were compared and analyzed. In preparations of few months old fetal material we observed arteries of fairly straight course, low caliber and with no observable ramification. When preparations of more mature stillborn infants were examined, we detected arteries of undulating course, more expressed ramification and higher caliber. In stillborn babies, all three arteries are of high caliber with rich branching. Considering that in this phase of brain development sulcuses are relatively wide, we can say that course of arteries is partially tortuous. Analysis of venous vessels shows good distinction of venous sinuses and subarachnoidal cisterns. We can conclude with great certainty that the changes occur in position, caliber and relationship among vessels in fetus during the period of brain sulci and gyri formation.