上矢状窦旁大脑上静脉末段的形态特点及其临床意义

目的:通过显微解剖和铸型方法观察上矢状窦旁大脑上静脉末段形态特点,为上矢状窦血栓发生及其准确及时的诊断提供形态学依据。方法:分别观测30例(60侧)静脉内灌注蓝色乳胶的成人头颅湿标本和观察12例胎儿和幼儿的脑静脉血管铸型。结果:上矢状窦前部和后部分别有一缺乏桥静脉注入段;前段上矢状窦旁大脑上静脉平均为5.2支,直径为(1.99±0.86)mm,末段可顺行、垂直和逆行注入上矢状窦;后段上矢状窦旁大脑上静脉为6.0支,直径为(2.96±1.13)mm,末段大部分逆行注入上矢状窦。结论:大脑上静脉末段的形态可能与上矢状窦内血栓发生密切相关,影响上矢状窦血栓的影像学观察。     

上矢状窦旁桥静脉的解剖及其血流动力学数值模拟

目的 通过对上矢状窦旁桥静脉的血流动力学数值模拟,为脑静脉血栓形成发病机制的解释和影像学诊断提供形态学证据。方法 对6例（12侧）上矢状窦和颈内静脉灌注蓝色乳胶的成人头颅湿标本进行观测,测量各支桥静脉的直径及其注入上矢状窦的角度;利用解剖数据,应用计算流体力学分析软件Fluent,建立上矢状窦旁桥静脉的血流动力学模型,对不同模型的壁面剪切力进行比较分析。结果 上矢状窦旁桥静脉共计137支,分为前后两组,其中后组桥静脉的直径较大,注入上矢状窦的角度较小。共建立模型137个,桥静脉直径>1.2mm、65°≤注入角度<105°时,注入处下游上矢状窦壁壁面剪切力下降明显;桥静脉直径>1.2 mm、注入角度<65°时,注入处下游上矢状窦壁和注入处上游桥静脉壁壁面剪切力下降明显,桥静脉壁壁面剪切力最低值为上矢状窦壁上的63%。与前段组桥静脉模型相比较,后段组模型上矢状窦壁和桥静脉壁壁面剪切力最低值较小,距注入处较远。结论 桥静脉直径>1.2mm,且注入角度<65°时,血管壁面剪切力急剧下降,脑静脉血栓形成容易发生。血栓好发于上矢状窦后段的注入处上游桥静脉壁。     

上矢状窦起始段及其桥静脉属支的解剖学研究

目的:探讨上矢状窦血栓形成的原因及上矢状窦与其它硬脑膜静脉窦之间吻合的意义。方法:观察3例新鲜胎儿及婴儿尸体头部制作ABS铸型标本,15例湿性成人尸头标本的上矢状窦起始段形态及注入该部位桥静脉的支数、管径及其与周围其它硬脑膜静脉窦之间的吻合情况。结果:上矢状窦起始段的前端均为闭锁端,起始段长度为(10.9±1.0)cm,由前向后逐渐变宽,注入上矢状窦起始段的桥静脉多位于大脑半球的外侧面,左侧和右侧分别为(6.4±4.2)支和(5.6±3.4)支。上矢状窦通过大脑中浅静脉与海绵窦的吻合。结论:上矢状窦管腔内横穿小梁和纤维索以及桥静脉的锐角逆行注入是血栓形成的形态学和血液流变学基础;上矢状窦借大脑中浅静脉与海绵窦的吻合是保证上矢状窦的静脉血回流的形态学基础之一。     

上矢状窦旁大脑桥静脉的观察及其临床意义

临床上各种纵裂间手术入路和手术过程中常损伤上矢状窦旁桥静脉,桥静脉损伤后可引起和加重不同程度的手术后并发症[1-6],为了减轻和避免手术后并发症必须熟悉和了解上矢状窦旁桥静脉的显微解剖,从而在手术入路和手术过程中避免损伤桥静脉或损伤桥静脉后进行桥静脉重建[7,8]。在脑静脉系统血栓发生中,约70%发生于上矢状窦,病因和发病机制多种多样,但目前尚有1/3的患者找不到确切的病因[9,10]。由于脑静脉血栓临床症状和体征缺乏特异性,诊断主要依赖影像学检查,而准确和及时的诊断对于脑静脉血栓的预后具有决定性的作用[10,11]。桥静脉为脑的…     

上矢状窦窦腔内纤维索分布的解剖学特征

目的:观察上矢状窦不同节段窦腔内纤维索的分布特征,探讨其功能和意义.方法:成人头颅湿性标本,15例沿上矢状窦上壁长轴中线纵行剖开,5例沿垂直眦耳线的冠状面作连续断层切片.将上矢状窦分为有桥静脉注入的前段、缺乏桥静脉注入的前缺乏段、有桥静脉注入的后段和上矢状窦后部的后缺乏段,观察纤维索结构在上矢状窦各段窦腔内的分布情况及形态.结果:上矢状窦窦腔内纤维索总数目为277个,其中瓣膜状纤维索131个,覆盖53%逆行注入上矢状窦的桥静脉注入口,74%的瓣膜状纤维索分布在上矢状窦注入后段,22%分布在注入前段;小梁状纤维索85个,58%分布在上矢状窦注入后段,20%分布在注入前段;板层状纤维索61个,64%分布在上矢状窦注入后段,33%分布在后缺乏段接近窦汇处.断层解剖能准确区分3种纤维索结构.结论:上矢状窦窦腔内纤维索具有节段性分布的特征,可能与上矢状窦血栓形成的发生有关.     

上矢状窦旁桥静脉的显微解剖与影像学观察

目的:通过对上矢状窦(SSS)旁大脑桥静脉的显微解剖、影像学观察及其对照研究,为各种纵裂间手术入路中桥静脉的保护提供基础。方法:分别对30例(60侧)上矢状窦和颈内静脉内灌注蓝色乳胶的成人头颅湿标本、40侧DSA静脉相和16侧CTV进行显微解剖和影像学观察。结果:上矢状窦前部和后部分别有一缺乏桥静脉注入段,显微解剖、DSA和CTV观察上矢状窦旁桥静脉的数量分别为11.2支、8.9支和7.0支,DSA和CTV观察发现桥静脉注入上矢状窦处常显示不清。结论:熟悉和比较上矢状窦旁桥静脉的解剖学和影像学特征有利于各种纵裂间手术入路和手术过程中桥静脉的保护。     

上矢状窦旁桥静脉注入口的显微解剖学观察及其意义

目的通过显微解剖观察上矢状窦旁桥静脉注入口的形态特点,为脑静脉血栓形成发病机理的解释提供形态学依据。方法 30例(60侧)成人头颅湿性标本,观测记录注入口的数目、分布、类型及走行。结果上矢状窦旁桥静脉共有注入外口367个(桥静脉与硬脑膜连接处,位于上矢状窦腔外),注入内口(桥静脉在上矢状窦腔内的开口)375个,其中有8个注入外口分别对应两个注入内口。注入口集中分布在上矢状窦前段和后段,分直接注入和间接注入(注入外口经脑膜静脉或硬膜旁窦走行一段距离后到达注入内口)两种类型。37%的上矢状窦后段注入口为间接注入,其中85%使得桥静脉由逆行注入上矢状窦变为垂直或顺行注入。结论上矢状窦旁桥静脉注入口复杂多样,且常使桥静脉逆行、垂直和顺行注入上矢状窦内的方式发生改变,在一定程度上可以对抗脑静脉血栓形成的发生。     

上矢状窦内纤维索结构的显微解剖和临床意义

目的:观察上矢状窦腔内纤维索的形态分类、分布,了解纤维索的功能和意义.方法:10具尸头标本,沿上矢状窦上壁长轴中线纵行剖开,体视学显微镜下观察腔内各种纤维索的形态分类、分布特点,记录各类纤维索的数目.结果:纤维索多分布于上矢状窦中段和后段,主要有3种类型:瓣膜状、小梁状和板层状.10具标本纤维索总数210个,瓣膜状纤维索100个,小梁状纤维索64个,板层状纤维索46个,分别占总数的47.62%、30.47%和21.91%.瓣膜状纤维索覆盖大脑上静脉注入上矢状窦的人口处,开口方向和静脉注入上矢状窦方向相同;小梁状纤维索以单个、多个或不同角度交叉方式出现,位于窦中央或一侧;板层状纤维索宽大,跨度长,将上矢状窦管腔分隔成两个分流腔,几乎都位于上矢状窦后段,结论:(1)上矢状窦内纤维索有瓣膜状、小梁状和板层状3种类型;(2)瓣膜状纤维索,具有防止窦内血流逆流入大脑上静脉的作用;(3)小梁状纤维索有增加窦壁弹性、增强窦壁抗压性、为瓣膜状纤维索提供摆动的着力点等作用;(4)板层状纤维索町以防止血流变慢和血液湍流、保证窦内血液迅速向窦汇回流.     

右侧颈外静脉缺如合并头静脉汇入点变异1例

目的　探讨颅内深静脉血栓形成（deep cerebral venous thrombosis,DCVT）的临床诊断与治疗策略。 方法　回顾性分析10年来影像学诊断为DCVT的5例患者的临床表现、影像学特征、治疗及预后情况。 结果　DCVT最常累及Rosenthal基底静脉、大脑内静脉、Galen静脉和直窦,其临床表现不典型,常见有头痛、意识障碍、复视、偏瘫等,常见诱发因素有口服避孕药、产褥期、妊娠期等。丘脑水肿为DCVT患者最常见的影像学征象。肝素抗凝治疗简单有效,大脑深静脉可恢复再通,临床症状缓解。 结论　DCVT患者临床症状缺乏特异性,早期诊断困难,特殊成像技术和特定影像学特征有助于其明确诊断,及时正确的抗凝治疗可获得良好的预后。     

上矢状窦神经分布及其临床意义

用5例新鲜成人硬脑膜标本,固定后将上矢状窦按前、中、后三段进行冰冻纵、横切片,银染后在光镜下观察。结果表明,上矢状窦各壁均有神经分布。其中后段神经最多,中段次之,前段最少。此结果一方面说明上矢状窦可能与头痛有关;另方面它的神经可参与调节上矢状窦的血流,从而影响脑表面的静脉回流。     

颅内深静脉血栓形成的临床诊治

目的　探讨颅内深静脉血栓形成（deep cerebral venous thrombosis，DCVT）的临床诊断与治疗策略。 方法　回顾性分析10年来影像学诊断为DCVT的5例患者的临床表现、影像学特征、治疗及预后情况。 结果　DCVT最常累及Rosenthal基底静脉、大脑内静脉、Galen静脉和直窦，其临床表现不典型，常见有头痛、意识障碍、复视、偏瘫等，常见诱发因素有口服避孕药、产褥期、妊娠期等。丘脑水肿为DCVT患者最常见的影像学征象。肝素抗凝治疗简单有效，大脑深静脉可恢复再通，临床症状缓解。 结论　DCVT患者临床症状缺乏特异性，早期诊断困难，特殊成像技术和特定影像学特征有助于其明确诊断，及时正确的抗凝治疗可获得良好的预后。     

Radiological and histological changes following cerebral venous sinus thrombosis in a rat model

Cerebral venous sinus thrombosis (CVST) is an important cause of stroke in young especially after pregnancy. We induced CVST in rat by topical application of ferric chloride over the exposed superior sagittal sinus (SSS) and pathological changes were monitored on days 1, 2 and 7. Thrombus weight was estimated and H&E staining was performed for comparison with MRI data. T2 weighted signal changes were present in all the study group rats. T2 hyper intensity decreased over the time. In study group, the apparent diffusion coefficient (ADC) was decreased by 31.94% on day 1 compared to the controls. There was 15.5% increase in the ADC value on day 2 compared to day 1 which reached almost equal to control value on day 7. On histological evaluation, neuronal necrosis and cellular infiltration were observed in cortical region after thrombosis. The early decrease in ADC could be attributed to cytotoxic edema that precedes vasogenic edema indicated by normalization of ADC and a decreased T2 hyper intensity. In conclusion, ferric chloride induced CVST in the rat produces cytotoxic edema in early stage followed by vasogenic edema which is related to recanalization of the superior sagittal sinus.     

Superior sagittal sinus thrombosis and transient ischemic attacks: possible mechanism.

Clinical manifestations of superior sagittal sinus (SSS) thrombosis are nonspecific but characterized by headache, papilledema, seizures, focal deficits, progressive coma and death. Recurrent transient focal neurologic deficit is an extremely rare manifestation in superior sagittal sinus thrombosis and the mechanism is unknown. A 45-year-old man presented with headache for two weeks and four episodes of transient (5-10 minutes) right or left hemiparesis for two days. Magnetic resonance image and transfemoral cerebral angiography revealed superior sagittal sinus thrombosis with numerous prominent collateral venous channels. There was no parenchymal lesion. After four days of heparinization, no further transient focal neurologic deficits developed. Follow-up angiography showed partial recanalization of the SSS. Possible mechanism of transient ischemic attacks in this patient is thought to be a transient functional disturbance due to a temporal reduction of tissue perfusion in the process of operating fully-enough collateral channels.     

Studies of free radical generation by neurons in a rat model of cerebral venous sinus thrombosis

The role of free radicals in the pathogenesis of arterial stroke is well documented but not in venous stroke. The aim of the study was to investigate the possible role of free radicals in the pathogenesis of cerebral venous sinus thrombosis (CVST). For inducing CVST in Sprague–Dawley rats, a cranial window was made to expose the superior sagittal sinus (SSS). On the exposed sinus, a strip of filter paper soaked with 40% ferric chloride was applied. In the control rats 0.9% saline was used instead of ferric chloride. After induction of sinus thrombosis, clinical evaluations were done on days 1, 2 and 7 for neurological deficit, weight of thrombus and brain lesion volume. In neuronal-rich cell preparations flow cytometric estimations were done at different time points. In the study group on sequential follow-up, there was spontaneous recanalization of SSS as well as a significant decrease in brain lesion volume. An insignificant improvement in neurological deficit was also observed. In the controls, there was no neurological deficit or evidence of infarction. Neuronal free radical levels were significantly increased in the study group on day 1 compared to controls, but on follow-up free radicals levels decreased. It is concluded that the free radicals increase in the early stage of venous stroke and may be important in its pathogenesis.     

New concept of cerebrospinal fluid dynamics in cerebral venous sinus thrombosis

Cerebral venous sinus thrombosis develops as a consequence of sinus obstruction, leading to hindering of venous drainage, gradual edema and increased intracranial pressure (ICP). Intracerebral hemorrhage occurs, of which the symptoms may be alleviated by cerebrospinal fluid (CSF) drainage. Clinical brain function improvement may be directly attributed to the effect of the decreased ICP, or to the decreased pressure on the venous sinus which alleviates venous blood flow and sinus thrombosis. However, worsening, rather than improvement of symptoms are occasionally observed in patients after CSF drainage, and therefore it is as yet difficult to determine the precise indications for CSF drainage. The authors of this study suggest that external CSF drainage of sagittal sinus thrombosis may accelerate the sinus thrombosis and aggravate symptoms in such a patient. In other words, the sagittal sinus differs from other sinuses in that when sinus thrombosis develops, CSF absorption is impeded from the early stages, leading to a higher likelihood of ventricular dilatation, because most of the CSF are normally absorbed through the arachnoid villi and drain into the sagittal sinus. External CSF drainage and subsequently decreased ICP will improve sinus thrombosis after implementation of CSF drainage of the sagittal sinus thrombosis, but on the other hand, this decreased CSF drainage leads to decreased venous sinus blood flow, both of which may result in aggravation of the sinus thrombosis. However, it is also suggested that CSF drainage may be accomplished safely on the unilateral lateral sinus thrombosis because CSF drainage may alleviate venous sinus obstruction, and does not influence the sinus blood flow. We, authors of this study suggest that caution should be taken when external CSF drainage of the sagittal sinus thrombosis is performed to prevent further aggravation of intracranial pressure elevation.     

Systemic lupus erythematosus complicated with cerebral venous sinus thrombosis : a report of two cases.

A rare manifestation of systemic lupus erythematosus (SLE) is cerebral venous sinus thrombosis (CVST), in which early diagnosis and aggressive therapy are of prime importance for favorable outcome. The pathogenesis of CVST is largely unknown, but it is thought to be caused by cerebral vasculitis, antiphospholipid antibodies or other conditions associated with enhanced coagulability. We describe two cases of SLE with CVST which were not associated with antiphospholipid antibodies. Both cases were treated with immunosuppressants (intravenous methylprednisolone and cyclophosphamide pulse therapy) and anticoagulant drugs (heparin and subsequent maintenance therapy with warfarin). There was a marked improvement of neurologic symptoms with the disappearance of thrombus in a follow-up MRI. The possibility of CVST should be considered in any patients with SLE who show neuropsychiatric manifestations.     

Cerebral Blood Flow and Oxygen Consumption in Rat,Measured with Microspheres or Xenon

The cerebral blood flow and, in some rats, the cerebral rate of oxygen consumption were measured in three groups of male rats. Fractionation of radioisotope-labeled microspheres was used to measure regional cerebral blood flow in four parts of the rat brain. The arterial and cerebral venous concentrations of radioactive xenon during desaturation were used to measure the blood flow and oxygen consumption of cortex when venous blood was collected from the superior sagittal sinus, or of whole brain when the transverse sinus was sampled. The regional cerebral blood flow measured with microspheres had a large standard error reflecting the technical difficulty of this method. The cerebral blood flow measured with xenon was higher when venous blood was sampled from the superior sagittal sinus than when sampled from the transverse sinus, but cerebral oxygen consumption rates were similar. The difference reflects the greater trauma involved in the superior sagittal approach and possible extracerebral contamination present in the transverse sinus approach.     

Cerebral blood flow and oxygen consumption in rat, measured with microspheres or xenon.

The cerebral blood flow and, in some rats, the cerebral rate of oxygen consumption were measured in three groups of male rats. Fractionation of radioisotope-labeled microspheres was used to measure regional cerebral blood flow in four parts of the rat brain. The arterial and cerebral venous concentrations of radioactive xenon during desaturation were used to measure the blood flow and oxygen consumption of cortex when venous blood was collected from the superior sagittal sinus, or of whole brain when the transverse sinus was sampled. The regional cerebral flow measured with microspheres had a large standard error reflecting the technical difficulty of this method. The cerebral blood flow measured with xenon was higher when venous blood was sampled from the superior sagittal sinus than when sampled from the transverse sinus, but cerebral oxygen consumption rates were similar. The difference reflects the greater trauma involved in the superior sagittal approach and possible extracerebral contamination present in the transverse sinus approach.