Transarterial embolization of cerebral arteriovenous malformations: A durable treatment for venous side hemorrhage?

Cerebral arteriovenous malformations (AVMs) have been occasionally reported to bleed from their venous side. This may particularly be the case when venous ectasias or aneurysms develop in the setting of steno-occlusive venopathy. Venous side hemorrhage should be suspected when the hematoma is centered on the venous pouch or when a venous pseudoaneurysm is identified on angiography. For AVMs with an identifiable point of rupture, early treatment is recommended in an attempt to secure the weak spot and minimize the risk of rerupture. When possible, microsurgical resection is the definitive and preferred treatment. In contrast, because of its latency period, stereotactic radiosurgery does not confer immediate protection in such cases. Endovascular transarterial embolization may offer immediate cure to only a minority of small AVMs, but remains a very useful temporizing strategy for arterial rupture sites such as proximal or intranidal aneurysms, allowing to defer definitive AVM treatment by either microsurgery or radiosurgery to a later stage. However, when the rupture site is venous in location and the AVM cannot be readily cured by either microsurgery because of its location in eloquent brain or embolization because of its large size, protecting patients from early rerupture may become problematic. We propose that, by reducing flow through the AVM, transarterial embolization may lead to secondary thrombosis of venous pseudoaneurysms and confer durable occlusion of these weak spots, pending definitive AVM cure. Therefore, transarterial embolization should be routinely attempted in such difficult-to-manage cases. An illustrative clinical case is presented in support of this hypothesis.     

Clinical manifestations in a large hereditary hemorrhagic telangiectasia (HHT) type 2 kindred

HHT type 2 (HHT 2) is a multi-system vascular dysplasia caused by a mutation in the ALK-1 gene, but the phenotype has not been well defined. We report on 51 members of an HHT 2 kindred with an ALK-1 gene mutation shown to be associated with the disorder. This ALK-1 mutation was detected in 38 kindred members who were evaluated systematically for associated vascular abnormalities. Pulmonary arteriovenous malformations (AVMs) were found in 6% of those screened, cerebral AVM in 7%, hepatic AVM in 17%, and spinal AVM in 3%. We discuss these and other findings in the 38 affected kindred members, as well as findings in the 13 kindred members in whom the mutation was not detected. This study shows that pulmonary, cerebral, spinal, and hepatic AVMs can all occur in HHT 2. It also adds to the evidence suggesting that pulmonary AVMs are more common in HHT 1 than in HHT 2. We identify a higher prevalence of hepatic AVMs than previously reported in either HHT 1 or 2. This may be specific to the mutation in this kindred, but probably reflects the lack of routine screening for this manifestation. Even in this family in which all affected individuals have the same mutation, the clinical manifestations of HHT and their severity varied tremendously. Intrafamilial variation in expression of HHT is clearly significant, emphasizing the difficulty in establishing the diagnosis in individuals and in sub-typing families when DNA testing is not available.     

105例脑动静脉畸形并出血的外科治疗

目的探讨脑动静脉畸形及合并出血后外科治疗方法的选择。方法105例病人根据脑动静脉畸形的分级、出血的部位、出血量的大小及病人的状况等选择手术、栓塞或栓塞后手术等方法治疗。结果手术组60例,全切除55例,占92%;部分切除5例,占8%。血管内治疗40例,一次全部栓塞的15例,占37%;分次全部栓塞的18例,占45%;部分栓塞的7例,占18%。血管内治疗后手术5例,全切除3例,占60%;部分切除2例,占40%。治愈91例,治愈率为86%;好转6例,占6%;死亡8例,占8%。结论手术治疗和血管内治疗是目前治疗脑动静脉畸形并出血的有效方法。     

Three-Dimensional Angles of Confluence of Cortical Bridging Veins and the Superior Sagittal Sinus on MR Venography

Few neuroimaging anatomic studies to date have investigated in detail the point of entry of cortical bridging veins (CBVs) into the superior sagittal sinus (SSS). Although we know that most CBVs join the SSS at an acute angle opposite to the direction of SSS blood flow, the three-dimensional (3-D) spatial configuration of these venous confluences has not been studied previously. This anatomical information would be pertinent to several clinically applicable scenarios, such as in planning intracranial surgical approaches that preserve bridging veins; studying anatomical factors in the pathophysiology of SSS thrombosis; and when planning endovascular microcatheterization of pial veins to retrogradely embolize brain arteriovenous malformations (AVMs). We used the concept of Euclidean planes in 3-D space to calculate the arccosine of these CBV–SSS angles of confluence. To test the hypothesis that pial AVM draining veins may not be any more acutely angled or difficult to microcatheterize at the SSS than for normal CBVs, we measured 70 angles of confluence on magnetic resonance venography images of 11 normal, and nine AVM patients. There was no statistical difference between normal and AVM patients in the CBV–SSS angles projected in 3-D space (56.2° [SD = 22.4°], and 46.2° [SD = 22.3°], respectively; P > 0.05). Hence, participation of CBVs in drainage of pial AVMs should not confer any added difficulty to their microcatheterization across the SSS, when compared to the acute angles found in normal individuals. This has useful implications for potential choices of strategies requiring endovascular transvenous retrograde approaches to treat AVMs. Clin. Anat. 33:293–299, 2020. © 2019 Wiley Periodicals, Inc.     

脑动静脉畸形血流动力学的理论模型研究进展

脑动静脉畸形 (脑 AVM)可导致脑血流的异常分布 ,不正常的血流动力学状态是脑 AVM发生脑内出血和造成某些神经功能障碍以及严重的手术并发症的重要原因之一。由于脑血管内血流压力、流量等血流动力学参数测量技术的局限 ,一些学者借助于理论模型来分析脑 AVM的血流力学特征。本文介绍了国外关于脑 AVM血流动力学理论模型研究的进展 ,论述了各类模型的特点和缺陷以及进一步研究的思想路线。     

Determination of Blood Flow Velocity and Transit Time in Cerebral Arteriovenous Malformation using Microdroplet Angiography

Advancement in imaging and biomedical technology has improved the use of catheter-based transarterial embolization (occlusive therapy) of cerebral arteriovenous malformations (AVMs). Among a variety of embolic agents, liquid adhesives (acrylates) have proven to be more successful in permanent obliteration of AVMs. The use of liquid adhesives requires the experience and skill of the operator. However, acquiring accurate information on blood flow and transit times through the AVM prior to embolization can optimize the treatment. In addition, knowledge of the polymerization time and behavior of the acrylate enables a complete and safe occlusion of the arteriovenous transition within the AVM nidus. Standard commercially available iodine-based contrast agents seem to be insufficient to determine AVM transit times from angiograms. For a more accurate assessment of AVM transit times, the use of a nonsoluble contrast agent (Ethiodol) and a high-speed digital subtraction angiography (DSA) is suggested. Small amounts (<20 l) of Ethiodol were infused to create microdroplets and traced using DSA at 15 fps. Transit time, defined as the time interval required for a droplet to reach the venous part of the AVM after being flushed from the tip of the catheter, could be accurately calculated. Postprocessing was used to calculate trajectories and velocities of microdroplets. © 2001 Biomedical Engineering Society. PAC01: 8719Uv, 4755Dz, 8719La, 8759Bh     

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.     

脊髓髓内动静脉畸形血管构筑学分析及其对治疗的启示

目的　探讨脊髓髓内动静脉畸形(SAVM)的血管构筑从而选择适宜的治疗方式。材料和方法　回顾性分析本中心治疗的120例SAVM病人的临床资料、血管造影影像资料及治疗方法和效果。结果　根据脊髓髓内动静脉畸形团的形状,将AVM分成两种类型：团块型和幼稚型。血管构筑学分析包括供血动脉、供血方式、伴随病变。其供血动脉为脊髓前动脉、脊髓后动脉和/或软膜动脉。经超选择脊髓血管造影可见畸型团有5种构筑方式：(1)终末供血形式,本组104例行栓塞治疗,其中85例单纯栓塞,70例神经功能恢复与改善;19例行术前栓塞、减少术中出血;(2)穿支供血形式本组16例,少量部分的用颗粒栓塞,栓塞后症状均改善;(3)动静脉直接交通1例;(4)AVM伴有动脉瘤13例,首先行动脉瘤栓塞;(5)AVM含有静脉动脉瘤样扩张2例。结论　脊髓髓内AVM的血管构筑学有助于选择治疗方案,终末型供血可行胶栓塞。穿支供血只能少量部分的用颗粒栓塞。AVM内的动脉瘤应首先栓塞,可明显减少再出血的危险。团块型AVM术前栓塞有利于手术切除。幼稚型AVM只能栓塞治疗。     

Improved target volume characterization in stereotactic treatment planning of brain lesions by using high-resolution BOLD MR-venography.

In this methodological paper I report the stereotactic correlation of different magnetic resonance imaging (MRI) techniques [MR angiography (MRA), MRI, blood bolus tagging (STAR), functional MRI, and high-resolution BOLD venography (HRBV)] in patients with cerebral arterio-venous malformations (AVM) and brain tumors. The patient's head was fixed in a stereotactic localization system which is usable in both MR-systems and linear accelerator installations. Using phantom measurements global geometric MR image distortions can be 'corrected' (reducing displacements to the size of a pixel) by calculations based on modeling the distortion as a fourth-order two-dimensional polynomial. Further object-induced local distortions can be corrected by additionally measured field maps. Using this method multimodality matching could be performed automatically as long as all images are acquired in the same examination and the patient is sufficiently immobilized to allow precise definition of the target volume. Information about the hemodynamics of the AVM was provided by a dynamic MRA with the STAR technique, leading to an improved definition of the size of the nidus, the origin of the feeding arteries, whereas HRBV imaging yielded detailed and improved information about the venous pattern and drainage. In addition, functional MRI was performed in patients with lesions close to the primary motor cortex area, leading to an improved definition of structures at risk for the high-dose application in radiosurgery. In patients with brain tumors the potential of HRBV to probe tumor angiogenesis and its use in intensity-modulated treatment planning is still hampered by the open question of how to translate a BOLD signal pattern measured in the tumor to a dose distribution, which should be addressed in future studies.     

Endothelial cells from human cerebral aneurysm and arteriovenous malformation release ET-1 in response to vessel rupture

Cerebral aneurysms and arteriovenous malformations (AVM) are a common cause of stroke and cerebral hemorrage. Both are often discovered when they rupture, causing subarachnoid hemorrhage (SAH). SAH-induced vasospasm is mediated by enhanced vasoconstriction due to endothelin-1 (ET-1). We investigated whether endothelial cells (ECs) obtained from aneurysm and AVM express phenotypic and genotypic alterations contributing to the development of vasospasm after SAH. We isolated ECs from human AVM and aneurysm and then confirmed their EC origin by polymerase chain reaction and immunocytochemistry with endothelial markers. Experiments were also carried out with human cerebral microvascular and umbilical vein ECs (HCECs and HUVECs respectively) for comparison. We tested EC proliferation ability and microtubule formation in Matrigel at different cell passages. Five aneurysm (3 ruptured, 2 unruptured) and 3 AVM (2 ruptured, 1 unruptured) ECs were tested for ET-1 release in the culture medium. Aneurysm and AVM ECs expressed von Willebrand factor, Adrenomedullin, and exhibited a progressive reduction of proliferation and in vitro angiogenic ability after the V passage. Significantly higher levels of ET-1 have been detected in ECs from ruptured aneurysms and AVMs. We report the first successful isolation and characterization of primary EC lines from human cerebral vascular lesions. Augmented release of ET-1 is correlated with the rupture of the abnormal vessel confirming its role in vasospasm after SAH. Furthermore, ECs obtained from these vascular malformations can be used as an experimental model to study SAH-induced vasoconstriction.     

Dosimetric accuracy of a staged radiosurgery treatment

For large cerebral arteriovenous malformations (AVMs), the efficacy of radiosurgery is limited since the large doses necessary to produce obliteration may increase the risk of radiation necrosis to unacceptable levels. An alternative is to stage the radiosurgery procedure over multiple stages (usually two), effectively irradiating a smaller volume of the AVM nidus with a therapeutic dose during each session. The difference between coordinate systems defined by sequential stereotactic frame placements can be represented by a translation and a rotation. A unique transformation can be determined based on the coordinates of several fiducial markers fixed to the skull and imaged in each stereotactic coordinate system. Using this transformation matrix, isocentre coordinates from the first stage can be displayed in the coordinate system of subsequent stages allowing computation of a combined dose distribution covering the entire AVM. The accuracy of this approach was tested on an anthropomorphic head phantom and was verified dosimetrically. Subtle defects in the phantom were used as control points, and 2 mm diameter steel balls attached to the surface were used as fiducial markers and reference points. CT images (2 mm thick) were acquired. Using a transformation matrix developed with two frame placements, the predicted locations of control and reference points had an average error of 0.6 mm near the fiducial markers and 1.0 mm near the control points. Dose distributions in a staged treatment approach were accurately calculated using the transformation matrix. This approach is simple, fast and accurate. Errors were small and clinically acceptable for Gamma Knife radiosurgery. Accuracy can be improved by reducing the CT slice thickness.     

Neurophysiological characteristics of spinal arteriovenous malformations

The aim of the study was to identify the clinical and neurophysiological pattern of deficits in spinal arteriovenous malformations (AVM) to allow an early diagnosis which is the prerequisite for effective treatment by early surgery or embolization. Among 26 patients with myelographic signs of a spinal AVM, selective spinal angiography disclosed 20 cases with a dural AV-fistula (dAVF) and 6 patients with an intradural AV-malformation (iAVM). Although the main pathogenetic factor in both disorders may be different, clinical and neurophysiological findings proved to be of limited value in differential diagnosis. Clinical symptoms presented by the patients were a variable combination of lower motor neuron lesion, sphincter disturbance, sensory transverse lesion and partly additional signs of upper motor neuron involvement. Electromyography invariably showed an increased rate of polyphasia and frequently pathological spontaneous activity usually in several myotomes. Normal sensory conduction velocity of the sural nerve contrasted with almost regularly pathological SEP's after tibial nerve stimulation. The distribution if clinical and neurophysiological findings suggests rather widespread lesions of the lower cord and/or cauda equina, frequently at a lower level than the angiographically localized shunt. This suggests a vascular myelopathy on the basis of insufficient venous drainage at least for the frequent dural AV-anomaly.     

Primary benign vascular tumors and tumorlike lesions of the kidney: a clinicopathologic analysis of 15 cases

Primary benign vascular lesions of the kidney are uncommonly encountered in routine surgical pathology practice. They can, however, mimic malignancy or be an incidental finding adjacent to a malignancy. Fifteen specimens harboring 16 primary benign renal lymphatic/vascular lesions were identified from our files from 1999 to 2011 and subjected to a detailed pathologic evaluation and clinicopathologic correlation. Clinical and demographic data were available for all the 15 cases. There were ten males and five female patients with age range of 33?C74?years (mean 54?years). Lesions ranged from 0.5?cm to 40?cm (average, 6.6?cm). There were six arteriovenous malformations (AVMs), four hemangiomas, three anastomosing hemangiomas, two lymphangiomas, and one solid intravascular papillary endothelial hyperplasia (IPEH). Five AVMs were located in the kidney parenchyma and one in the pelviureteric system. Additional associated lesions ranged from renal stones to renal cell carcinoma in two cases (one lymphangioma and one AVM). One AVM was associated with a capillary hemangioma in the vicinity, and another with a history of renal cell carcinoma in the contralateral kidney. Capillary hemangiomas and lymphangiomas were noninfiltrative and lacked cytological atypia and mitotic activity. Except for a renal pelvic AVM, all other renal AVMs radiologically mimicked malignancy. The patients had undergone partial or radical nephrectomies except for the renal pelvic AVM which was laparoscopically excised. To the best of our knowledge, none of the cases had any syndromic/systemic associations. Benign vascular lesions of the kidney are rarely seen in routine surgical pathology practice, partly because a vast majority of them are medically treated by embolization. However, lesions mimicking renal malignancy are subjected to surgery. They may exist as isolated lesions or coexist with malignant lesions either in the ipsilateral or the contralateral kidney.     

White Matter Changes in Dementia: Role of Impaired Drainage of Interstitial Fluid

White matter abnormalities on magnetic resonance imaging (MRI) are associated with dementia and include white matter hyperintensities (WMH; also termed leukoaraiosis) and visible perivascular spaces (PVS). We review the potential role of impaired drainage of interstitial fluid in the pathogenesis of WMH and PVS. Whereas the volume of extracellular space in the grey matter is tightly controlled, fluid accumulates and expands the extracellular spaces of the white matter in acute hydrocephalus, vasogenic edema and WMH. Although there are no conventional lymphatic vessels in the brain, there is very effective lymphatic drainage for fluid and solutes along restricted pathways in the basement membranes of cerebral capillaries and arteries in young individuals. Lymphatic drainage of the brain is impaired with age and in association with apolipoprotein E ε4, risk factors for Alzheimer's disease and cerebral amyloid angiopathy (CAA). Deposition of proteins in the lymphatic drainage pathways in the walls of cerebral arteries with age is recognized as protein elimination failure angiopathy (PEFA), as in CAA and cerebral autosomal dominant arteriopathy and leukoencephalopathy (CADASIL). Facilitating perivascular lymphatic drainage from the aging brain may play a significant role in the prevention of CAA, WMH and Alzheimer's disease and may enhance the efficacy of immunotherapy for Alzheimer's disease.     

Hereditary hemorrhagic telangiectasia and risks for adverse pregnancy outcomes

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular dysplasia characterized by epistaxis, mucocutaneous telangiectasias, and arteriovenous malformations (AVM) in the brain, lung, liver, gastrointestinal tract, or spine. While pregnant women with HHT are known to have increased risks due to pulmonary AVMs, little is known about any increased risk for fetal birth defects or other adverse pregnancy outcomes. To investigate potential increased risk, individuals with a clinical diagnosis of HHT were asked to complete a survey composed of four sections: demographics, personal history of HHT, personal history of birth defects (modeled after state registries), and reproductive history. A total of 226 participants reported outcomes of 560 pregnancies, as well as self-reported personal history of birth defects. Of the 560 pregnancies, 450 (80.4%) resulted in 457 live births and 63 (13.8%) were pre-term. Of the 110 pregnancy losses, 80 (72.7%) were first trimester and five were stillborn. Anomalies considered to be medically or cosmetically significant were reported in 17 babies (3.7%). The presence of significant anomalies was not significantly associated with whether the baby had an HHT diagnosis (P=0.55) or the gender of the parent with HHT (P=0.32). Four liveborn babies and one stillborn had a cerebral AVM or hemorrhage in the perinatal period. Prevalence of uterine hemorrhage, pre-eclampsia, placental abnormalities, low-birth weight, and infertility did not appear increased over the general population. These data provide some reassurance that HHT does not lead to an appreciable increased risk for birth defects or other adverse pregnancy outcomes.     

Possible fractionated regimens for image-guided intensity-modulated radiation therapy of large arteriovenous malformations

The aim of this study was to estimate a plausible alpha/beta ratio for arteriovenous malformations (AVMs) based on reported clinical data, and to design possible fractionation regimens suitable for image-guided intensity-modulated radiation therapy (IG-IMRT) for large AVMs based on the newly obtained alpha/beta ratio. The commonly used obliteration rate (OR) for AVMs with a three year angiographic follow-up from many institutes was fitted to linear-quadratic (LQ) formalism and the Poisson OR model. The determined parameters were then used to calculate possible fractionation regimens for IG-IMRT based on the concept of a biologically effective dose (BED) and an equivalent uniform dose (EUD). The radiobiological analysis yields a alpha/beta ratio of 2.2 +/- 1.6 Gy for AVMs. Three sets of possible fractionated schemes were designed to achieve equal or better biological effectiveness than the single-fraction treatments while maintaining the same probability of normal brain complications. A plausible alpha/beta ratio was derived for AVMs and possible fractionation regimens that may be suitable for IG-IMRT for large AVM treatment are proposed. The sensitivity of parameters on the calculation was also studied. The information may be useful to design new clinical trials that use IG-IMRT for the treatment of large AVMs.     

急性脑出血后血肿腔引流液及外周血THR、MMP-9与脑水肿、神经功能损伤的相关性

目的 检测急性脑出血后血肿腔引流液及外周血中凝血酶（THR）、基质金属蛋白酶-9（MMP-9）动态变化,观察其与患者脑水肿、神经功能损伤的关系。方法 选择2017年1月~2019年6月我院收治的75例行血肿清除术或血肿钻孔引流术的急性脑出血患者为对象,分别于术后第1、3、7、14天采集外周血及血肿腔引流液,采用酶联免疫吸附法检测外周血及血肿腔引流液中THR、MMP-9表达水平,并测定各时点头颅CT所示脑水肿比值。采用美国国立卫生研究院卒中量表（NIHSS）评估患者术后第1、3、7、14天神经功能损伤情况,判断急性脑出血后血肿腔引流液及外周血中THR、MMP-9表达水平与脑水肿比值、NIHSS评分的相关性。结果 急性脑出血患者术后3、7天血肿腔引流液及外周血中THR、脑水肿比值、MMP-9高于术后1天（P＜0.05）,术后14天血肿腔引流液及外周血中THR、脑水肿比值、MMP-9均低于术后1、3、7天（P＜0.05）。术后3、7天血肿腔引流液及外周血中MMP-9高于术后1天（P＜0.05）,术后7天血肿腔引流液及外周血中MMP-9低于术后3天（P＜0.05）,急性脑出血患者术后3天NIHSS评分高于术后1天（P＜0.05）,术后7天NIHSS评分低于术后1、3天（P＜0.05）,术后14天NIHSS评分低于术后1、3、7天（P＜0.05）,急性脑出血后血肿腔引流液及外周血中THR、MMP-9与脑水肿比值、NIHSS评分均呈正相关（P＜0.05）。结论 脑出血后血肿腔引流液及外周血中THR、MMP-9动态变化与脑水肿、神经功能损伤密切相关,临床应引起足够重视。     

Cecal Polypoid Arteriovenous Malformations Removed by Endoscopic Biopsy

Colonic arteriovenous malformation (AVM) is one of the causes of lower gastrointestinal bleeding. Unlike small vascular ectasia or angiodysplasia, colonic AVM tends to be solitary, large in size, and identified endoscopically as flat or elevated bright red lesion. Herein, we report a case of non-solitary and small cecal AVMs which were removed by endoscopic biopsy. A 66-yr-old woman was referred for routine gastrointestinal cancer screening. She was suffering from diabetes, hypertension, end-stage renal disease, and anemia of chronic disease. On colonoscopic finding, three semi-pedunculated polyps, less than 5 mm in size, were noticed near to the appendiceal orifice. Since the lesions revealed normal-looking epithelium with converging folds on the cecal base, lesions were diagnosed as inflammatory polyps on gross finding. Three biopsies were taken from each lesion. Bleeding from the biopsied site ceased spontaneously. Histopathologic evaluation demonstrated intramucosal hemorrhage and dilated submucosal vessels which were consistent with polypoid colonic AVMs.     

Brain shift is central to the pathogenesis of intracerebral haemorrhage remote from the site of the initial neurosurgical procedure

Intracerebral haemorrhage remote from the site of surgery is an uncommon and poorly understood complication after neurosurgical procedures. Although patients under anticoagulant therapy or with perioperative elevated blood pressure are usually considered potentially at high risk of postoperative intracerebral haemorrhage, the aetiology is still unclear for patients without these predisposing factors. In this paper, we suggest that brain shift, unavoidably occurring during all neurosurgical procedures, might play a central role in the aetiology of postoperative remote intracerebral haemorrhage. Brain shift is mainly caused by gravity, aggressive intraoperative dehydration, and cerebrospinal fluid aspiration. Brain shift produces stretching and transient occlusion of the corticodural bridging veins draining into the peripheral dural sinus. Consequently, venous infarcts occur in the venous drainage territories and haemorrhagic transformation results when perfusion is re-established within ischemic tissue. To minimize brain shift and consequent risk of remote intracerebral haemorrhage, we recommend avoiding the use of hyperosmotic agents and cerebrospinal fluid drainage systems during neurosurgical procedures. Moderate head elevation during and immediately after surgery may improve cerebral venous drainage and reduces the risks of this life-threatening complication.