Variability of the division of the cortical branches of the posterior cerebral artery

This article presents a method of analysis of variation in the cortical branching of the posterior cerebral artery (PCA). The method takes account of previous observations and reflects various symptoms of such variation. Of 100 cerebral hemispheres into whose vessels a contrast medium was injected, 94 hemispheres have been qualified for further examination. In six hemispheres, there were anomalies of the PCA, which are not included in the present analysis of division. A general model of the division of the artery has been developed. On the basis of this model, principles of the analysis of the variation have been discussed. The model comprises of three elements. The first is the main trunk. The second is intermediate trunks. The third element may appear in two forms: proper cortical arteries and cortical arterial groups. The main trunk was defined as the vessels arising from the final division of the basilar artery with its end in the place of branching of the most peripheral proper cortical artery, that is, parieto-occipital artery. Intermediate trunks are these parts of the PCA that extend between the main trunk and proper cortical arteries or cortical arterial groups. The identification criterion for the intermediate trunks is its length, which is to be equal to or exceed the sum of the radius of the two vessels, which the intermediate trunk gives off. There have been distinguished primary and secondary intermediate trunks. Proper cortical arteries or cortical arterial groups are parts of the PCA by means of which blood is supplied directly to the cortex. Cortical branches of the PCA of a relatively constant topography and vascularization were termed proper cortical arteries. In some cases, cortical branches are accompanied by small vessels of varying number and size. They were named accessory cortical arteries. Proper cortical arteries together with accompanying accessory cortical arteries have been named cortical arterial groups. The number of the proper cortical arteries is considered to be constant and is six. The theory of combinations has been applied to establish all possible branching variants. There are 16 such variants. Eleven of them (68%) were represented in the analyzed material. In seven hemispheres (7.4%), intermediate trunks were not observed. In 87 hemispheres (92.6%), there were present primary intermediate trunks. In four hemispheres (4.2%), there were found primary and secondary intermediate trunks. Both proper cortical arteries and cortical arterial groups reached the first five cortical areas of the PCA. The last cortical area was reached by a cortical arterial group only.     

Anatomic variations of anterior cerebral artery cortical branches

The anterior cerebral artery (ACA) is a major vessel responsible for the blood supply to the interhemispheric region. The ACA segment after the anterior communicating artery (AComA) origin is called the distal ACA and has central and cortical branches. The cortical branches are distributed in the different regions of the orbital and medial part of the brain. The objects of this study are the anatomical variations found in the distal ACA. In 76 hemispheres the ACA distal branches were injected with latex and dissected under microscope magnification. Vessel diameters and distances between vessel origins and anterior communicating artery were recorded and analyzed. Microsurgical dissection was carried out to demonstrate anatomic variations of these vessels. Average diameter of ACA at origin was 2.61 +/- 0.34 mm and average diameter of cortical branches diameter ranged from 0.79 +/- 0.27 mm to 1.84 +/- 0.3 mm. Distances between vessel origin and AComA ranged from 7.68 +/- 3.91 mm (orbitofrontal) to 112.6 +/- 11.63 mm (inferior internal parietal). This study found anatomical variations: a single (azygos) ACA was present in one case and three in three cases. Crossing branches of the distal ACA to the contralateral hemisphere were present in 26% of the cases. In some cases a single ACA may supply the posterior hemispheric region through crossing branches. This calls attention to potential bilateral brain infarcts due to a single unilateral ACA occlusion.     

A vermian artery originating from the posterior cerebral artery: an anatomical case report

During the dissection of a posterior fossa in a cadaveric head, we found a solitary superior vermian artery (VA) originating from the posterior cerebral artery (PCA). On the right side, the VA arose from the precommunicating segment of the PCA. The VA distributed by giving off some branches to the interpeduncular fossa, cerebral peduncle, midbrain, cerebellar cortex, inferior colliculus, lingula, vermis and superior medullary velum. The right superior cerebellar artery (SCA) had a normal origin from the basilar artery (BA) and supplied the righ tentorial surface of the cerebellum by means of bifurcating into two major trunks. The left SCA had duplicated origin from the BA.     

A revised classification of hypoxic conditions

The precised classification of circulatory hypoxia described in the paper is principally different from those published earlier by that it discriminates between hypoxia preconditioned by impaired cardiac-muscle constriction, on the one hand, and hypoxia due to malfunctions of smooth muscles (SM), on the other hand. The genesis of SM malfunctions is predetermined by impaired interactions of serotonin with SM serotonin receptors. The clinical use of serotonin adipinat reduces the local organic and total-tissue hypoxia in different pathologies and provides for better treatment results. The mentioned precised classification can be used to gain more data on the tissue-hypoxia pathogenesis and to schedule the clinical-and-experimental research on the purpose-oriented basis.     

咽升动脉分支的解剖分组及其临床意义

目的:探讨咽升动脉及其主要分支在颈部颅底区域走行规律及其在血管内外治疗中的临床意义。方法:选择以10%甲醛固定并用乳胶灌注的8具（16侧）成人颅颈部标本,自颈总动脉分叉水平向上解剖至颅底骨质,分离显露咽升动脉及周围相关结构,观察咽升动脉的起源部位及主要分支,测量相关解剖学参数。依据咽升动脉主要分支与颈动脉鞘的位置关系分...     

椎动脉及大脑后动脉并后交通动脉变异1例

正解剖教学中发现1成年男尸右大脑后动脉有2支,起自基底动脉的右大脑后动脉外径明显小于左大脑后动脉和起自颈内动脉的右大脑后动脉;无右后交通动脉,左后交通动脉发育不良(图1)。描述如下:(1)椎动脉外径差大:双侧椎动脉均起自锁骨下动脉,左/右侧起始处、入枕骨大孔处和末端的外径为分别为3.78 mm/7.52 mm、2.66 mm/6.10 mm和1.74 mm/4.52 mm,起始处至寰椎横突孔上方的距离12.50 cm/12.99 cm。     

Temporal branch of the posterior cerebral artery arising from the posterior communicating artery diagnosed by MR angiography

We report a case in which the temporal branch of the posterior cerebral artery (PCA) arose from the posterior communicating artery (PCoA) and was diagnosed by magnetic resonance (MR) angiography. The PCoA arose from its normal point on the supraclinoid internal carotid artery and fused with the PCA at its normal point of the P1–P2 junction. We believe this is the first report of such a variation. Careful review of MR angiographic images is important to detect rare arterial variations, and partial maximum-intensity-projection images aid their identification on MR angiography.     

Territories of the perforating (lenticulostriate) branches of the middle cerebral artery

The territories of the central branches of the middle cerebral artery (MCA) were examined in 21 injected human brains. It was noted that these central arteries supplied: the caudate nucleus (dorsolateral half of the rostral part of its head; the entire caudal part of the head; the body and rostral portion of the tail in some cases), the putamen (dorsolateral part of its rostral portion, the remainder of the putamen, except the most caudal part occasionally), the globus pallidus (the entire lateral segment, except the ventrorostral and, sometimes, the most caudal part), the basal forebrain (lateral parts of the basal nucleus of Meynert and the nucleus of the diagonal band, as well as fiber bundles in this region), the internal capsule (dorsal and ventrocaudal part of the anterior limb, dorsal part of the genu, dorsal and ventrorostral part of the posterior limb), the corona radiata (a narrow strip close to the internal capsule) and the cerebral cortex (the caudal orbitofrontal cortex occasionally). The presented data may have certain neuroradiologic, neurologic and neurosurgical significance.     

Territories of the perforating (lenticulostriate) branches of the middle cerebral artery

Summary The territories of the central branches of the middle cerebral artery (MCA) were examined in 21 injected human brains. It was noted that these central arteries supplied: the caudate nucleus (dorsolateral half of the rostral part of its head; the entire caudal part of the head; the body and rostral portion of the tail in some cases), the putamen (dorsolateral part of its rostral portion, the remainder of the putamen, except the most caudal part occasionally), the globus pallidus (the entire lateral segment, except the ventrorostral and, sometimes, the most caudal part), the basal forebrain (lateral parts of the basal nucleus of Meynert and the nucleus of the diagonal band, as well as fiber bundles in this region), the internal capsule (dorsal and ventrocaudal part of the anterior limb, dorsal part of the genu, dorsal and ventrorostral part of the posterior limb), the corona radiata (a narrow strip close to the internal capsule) and the cerebral cortex (the caudal orbitofrontal cortex occasionally). The presented data may have certain neuroradiologic, neurologic and neurosurgical signifiance.

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Territoire des branches perforantes (lenticulo-striées) de l'artère cérébrale moyenne

Résumé Le territoire des artères centrales nées de l'ACM a été étudié sur vingt et un cerveaux humains injectés. Les artères centrales vascularisent : le noyau caudé (la moitié dorso-latérale de la partie rostrale de sa tête ; la totalité de la partie caudale de sa tête ; dans certains cas son corps et la partie rostrale de sa queue), le putamen (la partie dorso-latérale de sa portion rostrale ; parfois le reste du putamen, à l'exception de sa portion la plus caudale), le globus pallidus (la totalité de son segment latéral sauf sa partie ventro-rostrale et parfois sa portion la plus caudale), le cerveau basal (parties latérales du noyau basal et noyau de la bandelette diagonale, de même que les faisceaux des fibres de cette région), la capsule interne (partie dorsale et ventro-caudale du bras antérieur ; partie dorsale du genou; partie dorsale et ventrorostrale du bras postérieur), la couronne rayonnante (étroite bande bordant la capsule interne) et le cortex cérébral (parfois la partie caudale du cortex orbito-frontal). Ces données peuvent avoir une certaine importance en neuro-radiologie, neurologie et neuro-chirurgie.

     

A revised and extended classification of the distal arthrogryposes

Since the group of disorders known as the distal arthrogryposes (DAs) were defined, additional disorders characterized by multiple congenital contractures of the distal limbs were described, and the distribution of phenotypic findings in the DAs has been expanded. The breadth of disorders labeled as DAs has diminished the usefulness of the DA classification. We propose a strict definition of DA and diagnostic criteria for DA disorders. Subsequently, we use these standards and propose a revised classification of discrete conditions that should be labeled DAs. Optimally, this serves as a framework for a DA classification based on underlying molecular and physiologic abnormalities. © 1996 Wiley-Liss, Inc.     

Anatomy of the superficial temporal artery and its branches: its importance for surgery

The temporoparietal, parieto-occipital flaps or the forehead flaps that are used in reconstructive surgery are prepared on the superficial temporal artery (STA) and its branches. For a successful surgery and a suitable flap design, adequate anatomical knowledge is needed. In our study, the red colored latex solution was injected into the external carotid artery; the STA and its branches were dissected in 27 specimens. The mean diameter of the STA at the zygomatic arch was determined as 2.73±0.51 mm. The diameters of the frontal branch were bigger than those of the parietal branch in 15 samples out of 27. The diameters of both the frontal and parietal branches were equal in four samples. The diameter of the parietal branch was bigger than that of the frontal branch in eight samples. In 20 samples out of 27 (74.07%), the bifurcation point of the STA was above the arch. In six samples (22.22%), the STA bifurcated directly over the arch. In only one sample (3.70%), bifurcation was not observed and the STA continued only as a frontal branch (absence of the parietal branch). The absence of the frontal branch was not encountered. In one sample (3.70%), double parietal branches were observed. In six samples out of 27 (22.22%), zygomatico-orbital artery was not encountered. In 21 samples (77.77%), zygomatico-orbital arteries ran towards the face, parallel to zygomatic arch and distributed in the orbicularis oculi muscle. The transverse facial artery existed in all samples. The auricular branches running to the helix and tragus were observed in all samples. The STA was 16.68±0.35 mm at the front of the tragus. Some landmarks were chosen on the head and then the STA was observed where it crossed all of these landmarks. This paper confirms the well-known variability of the superficial temporal arterial branches and their relation to the pericranial region. Knowledge concerning the arterial features of the lateral forehead region is important for the aesthetic surgeon. STA and its branches have been found to be suitable for use in microvascular anastomoses. A better understanding of the midline forehead vascularity should allow modification of reconstructive techniques and reduce postoperative complications.     

The posterior inferior cerebellar artery and its branches in relation to the cerebellomedullary fissure

The conventional approach to the fourth ventricle is by splitting the vermis on the suboccipital surface of the cerebellum. By a unilateral transcerebellomedullary fissure approach, it is possible to provide sufficient operative space from cerebral aqueduct to obex without splitting the vermis. This approach needs meticulous dissection of the cerebellomedullary fissure and preservation of the posterior inferior cerebellar artery (PICA) and its branches. The tonsillomedullary and telovelotonsillar segments of the PICA are the most important vessels encountered in the transcerebellomedullary fissure approach. The PICA was examined under a surgical microscope in a total of 40 specimens by perfusing with a mixture of 10% Indian ink and gelatin. The passing of the tonsillomedullary segment of the PICA through the cerebellomedullary fissure was observed superior to the tonsil in 5%, at the level of the upper pole of the tonsil in 17.5%, at the middle of the tonsil in 37.5% and at the level of the lower pole of the tonsil in 37.5% specimens. When the PICA arose from the lateral medullary (LM) segment of the vertebral artery (VA), a caudal loop was present in 90%, when the PICA originated from the premedullary segment of the VA, the loop was present in 87.5% specimens. When the PICA arose from the basilar artery (BA), the loop was absent, and the tonsillomedullary segment of the PICA showed a straight course (100%). A thorough understanding of the relationship of the branches of the PICA to the cerebellar tonsils are prerequisites for surgery in and around the fourth ventricle.     

双侧胚胎型大脑后动脉患者基底动脉发育不良在后循环缺血发生中的作用

目的 探讨双侧胚胎型大脑后动脉患者基底动脉发育情况及其血流流速在后循环缺血发生中的作用。方法 前瞻性选取2014年3月—2015年5月包头医学院第三附属医院神经内科经1.5 T或3.0 T MRA证实为双侧胚胎型大脑后动脉的住院患者40例为观察组,以头晕等症状门诊就诊、头颅MRA显示无胚胎型大脑后动脉且基底动脉发育正常的52例患者为对照组。对所有实验对象的基底动脉直径在MRA原始图像上使用MR扫描仪自带VolumeView软件远、中、近三段中点截面进行测量;使用经颅多普勒(TCD)检测基底动脉血流流速,并对患者后循环缺血的发生情况进行统计分析。结果 观察组和对照组患者基底动脉直径分别为(1.98±0.20)mm、(3.40±0.47)mm,基底动脉血流流速分别为(36.0±5.6)cm/s 、(56.0±7.0)cm/s ,差异均有统计学意义(t=-19.602、-14.788, P值均<0.01);观察组患者后循环缺血的发生率20.0%(8/40),高于对照组的1.9%(1/52),差异有统计学意义(χ²=6.448, P<0.05)。结论 双侧胚胎型大脑后动脉患者基底动脉发育不良导致基底动脉血流流速减慢,致使后循环缺血的发生率升高,为后循环缺血的危险因素。     

手术夹闭合并同侧胚胎型大脑后动脉的后交通动脉瘤预后因素分析

目的探讨手术夹闭存在胚胎型大脑后动脉的后交通动脉瘤(PCoAA)预后的影响因素。方法选择徐州医科大学附属医院神经外科2015年1月至2019年1月经显微手术夹闭合并胚胎型大脑后动脉的PCoAA患者80例,术后6个月采用改良Rankin量表评价患者预后,采用单因素分析和多因素Logistic回归分析影响患者预后的因素。结果性别、动脉瘤侧别、宽颈、动脉瘤大小、脑梗死史、手术时机、高血压史对手术预后影响不大;而年龄、Hunt-Hess分级、改良Fisher分级是影响手术预后的危险因素。结论年龄、术前Hunt-Hess分级以及改良Fisher分级是患者预后不良的独立影响因素;对于年龄不大、Hunt-Hess低分级、改良Fisher低分级这类患者,更早进行显微外科手术治疗,安全性更高,预后更好。     

Early changes in cerebral aneurysms in the internal carotid artery/posterior communicating artery junction

In order to obtain information about preaneurysmal changes, the junction of the internal carotid artery/posterior communicating artery (ICA/PComA) in the circles of Willis in subjects with aneurysms at sites other than the junction, and in control subjects without aneurysms, were studied by light microscopy. Small evaginations and thinnings of the media with and without dilatation were observed at the apical areas of the forks with a significantly higher incidence in the aneurysm series than in the control, suggesting some predisposing factor in subjects with aneurysms. As well as funnel-shaped dilatations previously described as the only type of ICA/PComA preaneurysmal change, other more localized types were observed. All the small evaginations and about half of the thinnings and dilatations were observed at the apex in association with a medial gap, but the other half occurred at some distance from the apex. The thinned arterial wall showed degenerative changes of the elastic lamina and media. Intimal pads were observed at the apex, the ICA/PComA lateral angle and the ICA stem/branch curve. Their combination with preaneurysmal changes was more frequent in the aneurysm series in comparison with the control. Degenerative changes of the elastic lamina and media caused by hemodynamic stress due to branching structures including intimal pads are thus presumed to be the initial lesions existing prior to aneurysm formation.