高流量颅外内血管搭桥技术在颅底肿瘤手术中的应用进展

颅底肿瘤尤其是侵及颈内动脉等颅内主供血血管的肿瘤治疗一直是神经外科的难题,由于此类肿瘤与重要血管的关系密切,手术风险极大,导致治愈率底下。而颅外内血管搭桥技术通过重建颅内血运,可以有效提升此类肿瘤的全切率。本文回顾了高流量颅外内血管搭桥技术的历史进展、探讨了颅外内血管搭桥技术辅助切除颅底肿瘤的意义所在,复习文献归纳了该技术应用的适应症、术中注意事项及其疗效与争议,旨在为其临床推广应用提供更多的参考依据。熟练及合理地应用颅外内血管搭桥技术,制定个体化的治疗方案,复杂颅底肿瘤的治愈率将会得到进一步提升。     

颅底孔在多层CT三维重建中的测量研究

探讨颅底MSCT三维重建图像效果及主要孔的正常值,采用多层螺旋CT(MSCT),对200名正常成人(男100名,女100名)进行颅脑扫描,利用电子计算机三维重建程序立体地显示颅底外面的卵圆孔、棘孔、颈动脉管外口、破裂孔、茎乳孔、枕骨大孔,并观察其形态和测出其内径及其性差。     

Tension pneumocephalus secondary to osteoradionecrosis of the clivus

We report the case of a 36 year-old man with relapsing undifferentiated nasopharyngeal carcinoma treated with a re-irradiation Cyberknife, who subsequently developed tension pneumocephalus due to a cerebrospinal fluid leakage located at the clivus. The fistula was caused by osteonecrosis of the skull base secondary to the tumor invasion and to the sequelae of the radiotherapy. An endoscopic endonasal technique was used in order to repair the defect, with a peduncolated nasoseptal flap harvested to perform the skull base reconstruction. In this paper, we discuss the importance of identifying this possible complication related to radiotherapy in the management of neoplasm along the skull base; moreover, the role of endoscopy in the diagnosis and treatment of skull base fistulas is also described and commented.     

A method for making an endocranial cast through the foramen magnum of an intact skull

It is possible to make an endocranial cast through the foramen magnum of an intact skull by using several layers of liquid latex. The technique described here includes the preparation of the skull; the method of pouring and curing the layers of liquid latex; the loosening and removal of the latex cast; and lastly making the final endocranial cast.     

A new test set-up for skull fracture characterisation

Skull fracture is a frequently observed type of severe head injury. Historically, a variety of impact test set-ups and techniques have been used for investigating skull fracture. The most frequently used are the free-fall technique, the guided fall or drop tower set-up and the piston-driven impactor set-up. This document proposes a new type of set-up for cadaver head impact testing which combines the strengths of the most frequently used techniques and devices. The set-up consists of two pendulums, which allow for a 1 degree of freedom rotational motion. The first pendulum is the impactor and is used to strike the blow. The head is attached to the second pendulum using a polyester resin. Local skull deformation and impact force are measured with a sample frequency of 65 kHz. From these data, absorbed energy until skull fracture is calculated. A set-up evaluation consisting of 14 frontal skull and head impact tests shows an accurate measurement of both force and local skull deformation until fracture of the skull. Simplified mechanical models are used to analyse the different impacting techniques from literature as well as the new proposed set-up. It is concluded that the proposed test set-up is able to accurately calculate the energy absorbed by the skull until fracture with an uncertainty interval of 10%. Second, it is concluded that skull fracture caused by blunt impact occurs before any significant motion of the head. The two-pendulum set-up is the first head impact device to allow a well-controlled measurement environment without altering the skull stress distribution.     

Application of the finite-element method to simulation of damage to the human skull as a consequence of missile impact on a multi-layered composite crash helmet

Finite-element analysis is a powerful technique which could be applicable to the study of a wide range of circumstances where the frame and/or the vital organs of the body are subjected to extreme loading conditions. This paper reports the results of an exploratory investigation in which the performance of a crash helmet in protecting the skull from an impacting load is modelled. The immediate objective is to show how a typical crash helmet design of glass-reinforced plastic (GRP) outer casing with quasi-foam-like liner can, with a suitable choice of material properties, attenuate the transfer of energy from the impacting mass such that the damage intensity to the skull is minimized. A simplified structure for both helmet and skull shape is adopted and the skull is modelled as being supported on an elastic foundation. The material properties used are representative rather than being accurately matched to experimentally determined ones. Several aspects of the modelling technique are worthy of particular note: the simulation of material anisotropy by means of multiple reinforcement layers with varying orientation, the use of dashpot elements for energy attenuation and the incorpotation of multipoint constraint between the skull and the helmet lining to ensure integrity of the model with correct stiffness matrix values and allowing independent monitoring of all stress levels at the mating interface region. The results of the modelling show that the specific limited objectives can be met but also indicate how vitally important information could be obtained from similar but more detailed studies which included representative modelling of the body organs and skeleton.     

Technique and preliminary findings for in vivo quantification of brain motion during injurious head impacts

Computational models of the human brain are widely used in the evaluation and development of helmets and other protective equipment. These models are often attempted to be validated using cadaver tissue displacements despite studies showing neural tissue degrades quickly after death. Addressing this limitation, this study aimed to develop a technique for quantifying living brain motion in vivo using a closed head impact animal model of traumatic brain injury (TBI) called CHIMERA. We implanted radiopaque markers within the brain of three adult ferrets and resealed the skull while the animals were anesthetized. We affixed additional markers to the skull to track skull kinematics. The CHIMERA device delivered controlled, repeatable head impacts to the head of the animals while the impacts were fluoroscopically stereo-visualized. We observed that 1.5 mm stainless steel fiducials (∼8 times the density of the brain) migrated from their implanted positions while neutral density targets remained in their implanted position post-impact. Brain motion relative to the skull was quantified in neutral density target tests and showed increasing relative motion at higher head impact severities. We observed the motion of the brain lagged behind that of the skull, similar to previous studies. This technique can be used to obtain a comprehensive dataset of in vivo brain motion to validate computational models reflecting the mechanical properties of the living brain. The technique would also allow the mechanical response of in vivo brain tissue to be compared to cadaveric preparations for investigating the fidelity of current human computational brain models.     

Projection geometry and stress-reduction techniques in craniofacial surgery

Since 1981, we have been able to modify the mathematical patterns of projection geometry to reshape the skull in craniofacial surgery. Unlike burring, morcellization, rotation, and plate switching, this technique actually changes the shape of individual sections of the skull by changing their radius of curvature. The technique is an adaptation of the principles used by engineers to build complex structures such as ships' hulls, airfoils, and domes. The result is a rigid form of the desired shape that becomes permanent with healing. This has several advantages: 1. An increase in the level of safety of craniofacial procedures for remodeling the skull. This is so because there is no need to dissect normal areas as in the standard plate-switching techniques. 2. Decreased operating room time. 3. An increased range of surgical manipulations. No longer is the surgeon limited to the shape of the material present. 4. Relief of edge pressure on the frontal lobes during scalp closure. 5. Creation of a solid bony form over which the pericranial scalp flap can be draped to form new layers of bone.     

Avian skull morphological evolution: exploring exo- and endocranial covariation with two-block partial least squares

While rostral variation has been the subject of detailed avian evolutionary research, avian skull organization, characterized by a flexed or extended appearance of the skull, has eventually become neglected by mainstream evolutionary inquiries. This study aims to recapture its significance, evaluating possible functional, phylogenetic and developmental factors that may be underlying it. In order to estimate which, and how, elements of the skull intervene in patterning the skull we tested the statistical interplay between a series of old mid-sagittal angular measurements (mostly endocranial) in combination with newly obtained skull metrics based on landmark superimposition methods (exclusively exocranial shape), by means of the statistic-morphometric technique of two-block partial least squares. As classic literature anticipated, we found that the external appearance of the skull corresponds to the way in which the plane of the caudal cranial base is oriented, in connection with the orientations of the plane of the foramen magnum and of the lateral semicircular canal. The pattern of covariation found between metrics conveys flexed or extended appearances of the skull implicitly within a single and statistically significant dimension of covariation. Marked shape changes with which angles covary concentrate at the supraoccipital bone, the cranial base and the antorbital window, whereas the plane measuring the orientation of the anterior portion of the rostrum does not intervene. Statistical covariance between elements of the caudal cranial base and the occiput inplies that morphological integration underlies avian skull macroevolutionary organization as a by-product of the regional concordance of such correlated elements within the early embryonic chordal domain of mesodermic origin.     

版纳鱼螈的骨骼系统

以我国特有的珍稀濒危两栖动物版纳鱼螈(Ichthyophis bannanica)为材料,采用传统的脊椎动物骨骼标本制作技术与透明骨骼标本制作技术相结合的方法,对其骨骼系统进行了形态学研究,并与其他无足目和两栖动物相比较,探讨版纳鱼螈的亲缘关系和进化地位。结果表明,版纳鱼螈成体具头骨41枚,椎骨108~115枚,肋骨101~108枚,无四肢骨。头骨、椎骨和肋骨均具有适应于穴居、掘穴和夜行性习性的特征。版纳鱼螈与双带鱼螈(I.glutinosus)的头骨极为相似,却具有比Dermophis mexicanus的头骨更原始的特征。     

Cranial mechanics and feeding in Tyrannosaurus rex

It has been suggested that the large theropod dinosaur Tyrannosaurus rex was capable of producing extremely powerful bite forces and resisting multi-directional loading generated during feeding. Contrary to this suggestion is the observation that the cranium is composed of often loosely articulated facial bones, although these bones may have performed a shock-absorption role. The structural analysis technique finite element analysis (FEA) is employed here to investigate the functional morphology and cranial mechanics of the T. rex skull. In particular, I test whether the skull is optimized for the resistance of large bi-directional feeding loads, whether mobile joints are adapted for the localized resistance of feeding-induced stress and strain, and whether mobile joints act to weaken or strengthen the skull overall. The results demonstrate that the cranium is equally adapted to resist biting or tearing forces and therefore the 'puncture-pull' feeding hypothesis is well supported. Finite-element-generated stress-strain patterns are consistent with T. rex cranial morphology: the maxilla-jugal suture provides a tensile shock-absorbing function that reduces localized tension yet 'weakens' the skull overall. Furthermore, peak compressive and shear stresses localize in the nasals rather than the fronto-parietal region as seen in Allosaurus, offering a reason why robusticity is commonplace in tyrannosaurid nasals.     

山顶洞101号男性头骨的三维颅面复原

山顶洞101号头骨化石是东亚地区保存最为完整的化石之一,是探讨东亚地区现代人起源的重要研究材料。本文依据数据集中现生人的面部软组织平均分布,提出了计算机三维颅面复原方法,实现了101号头骨生前面貌的预测复原。主要包括三个步骤：首先使用CT完成了101号男性头骨和下颌骨仿制模型的三维重建。然后,利用计算机技术将现生人的面部软组织分布作为101号头骨的面部软组织分布,实现了颅面虚拟复原,并采用手工绘画技巧再现了复原面貌的形态特征。最后,提出了一种基于面部软组织分布和面貌统计形状模型的形态分析方法,实现了颅面复原结果的评估。山顶洞101号头骨的复原面貌具有头部较长、额头前倾、眉弓粗壮等特征,与101号头骨的几何形态基本一致。该技术再现了更新世晚期人类的脑颅及面部的形态特征,为古人类颅面复原的研究提供了技术支持和参考资料。     

Principal component analysis of dynamic relative displacement fields estimated from MR images

Non-destructive measurement of acceleration-induced displacement fields within a closed object is a fundamental challenge. Inferences of how the brain deforms following skull impact have thus relied largely on indirect estimates and course-resolution cadaver studies. We developed a magnetic resonance technique to quantitatively identify the modes of displacement of an accelerating soft object relative to an object enclosing it, and applied it to study acceleration-induced brain deformation in human volunteers. We show that, contrary to the prevailing hypotheses of the field, the dominant mode of interaction between the brain and skull in mild head acceleration is one of sliding arrested by meninges.     

应用3D适形打印制备网状复合体对兔颅骨缺损的修复作用及安全性研究

目的:探讨采用3D适形打印技术制备的羟基磷灰石/聚乳酸网状复合体在兔颅骨缺损中的修复作用及安全性。方法:以24只新西兰兔为研究对象,以羟基磷灰石/聚乳酸为材料,采用3D适形打印技术制备网状复合体,于兔颅骨顶部制成两个颅骨全层缺损,分别为孔A(左)和孔B(右),孔A(阳性对照组)以自体颅骨为修复材料,孔B(实验组)以复合体为修复材料,观察缺损修复区域的形态学、影像学(X线及CT扫描)及组织学检查结果。结果:植入后24周时,形态学显示:阳性对照组可见致密的骨组织修复,与缺损边缘界限不清,实验组中支架孔隙内纤维组织由新生骨质取代,且新生骨成熟度较提高,材料表面有部分吸收。CT扫描观察显示:冠状面上,阳性对照组缺损修复区域与周围正常骨组织融合为一体,实验组修复材料与缺损边缘融合紧密,与周围正常骨组织结合良好,部分边缘结合不连贯。组织学观察显示:实验组材料部分降解,材料间隔可见新生骨小梁。研究中无实验动物死亡,皮肤切口处缝合良好,无皮下积液,无移植物脱出、红肿感染等情况出现。结论:以3D适形打印技术制备的羟基磷灰石/聚乳酸复合体对兔颅骨缺损有较好的修复作用,能促进缺损区域新骨的形成和生长,且安全性较高。     

The harvesting of cranial bone grafts: a guided osteotome

A technique for in situ harvesting of the outer table of the skull using a "guided" osteotome is presented. While guards have been placed to control the depth of the blade, additional steps are advised to ensure the highest level of safety in clinical use: Before harvesting the graft, a full set of anteroposterior and lateral x-rays should be examined to determine which areas of the skull are thin and should be avoided. All areas with cranial sutures should be avoided because here the dura is more firmly attached to the inner table making perforation more dangerous. Bone should not be harvested under the hairless forehead region because this results in a visible depression. The surgeon should use the guards as guides to visually monitor the depth of the blade. The surgeon should not attempt the procedure without having a set of three different depths (1 mm, 2 mm, and 3 mm) available. Different skulls have different thicknesses of the outer table, and the technique loses the advantage of safety if an inappropriate depth is used.     

True serial-sectioning of fossil material

A method of cutting serial sections of fossil material using a very thin diamond annular saw, clamped under tension and revolving at 3000 rev/min is described. A small skull of the therapsid reptile Endothiodon has been cut into 104 serial sections 0–6 mm thick. The technique is still in its infancy, but is described to show its potentialities.     

True serial-sectioning of fossil material

A method of cutting serial sections of fossil material using a very thin diamond annular saw, clamped under tension and revolving at 3000 rev/min is described. A small skull of the therapsid reptile Endothiodon has been cut into 104 serial sections 0–6 mm thick. The technique is still in its infancy, but is described to show its potentialities.     

Comparative ontogenetic shape changes in the skull of Caiman species (Crocodylia,Alligatoridae)

Ontogenetic shape changes in the skull of three species of the genus Caiman (C. latirostris, C. sclerops, and C. yacare) are compared by geometric morphometrics for three-dimensional configurations (the least-squares analysis). The technique for obtaining the landmark coordinates is a simplification of the algorithm for multidimensional scaling. The ontogenetic nonlinear shape changes are similar in the three species but occur in a lesser extent in C. latirostris. These seem to be correlated with functional changes in the skull. The uniform shape change corresponds to an elongation of the skull, dorsoventral flattening, and lateral compression in C. sclerops and C. yacare. There is some lateral broadening in C. latirostris. Differences in the ontogenetic processes probably cause the differences in diet observed between C. latirostris and the other two species. Neotenic evolution seems to have acted in the skull of C. latirostris, and a posterior amplification of the early divergence led to a repatterning of the shape ontogenetic trajectory in this species. J. Morphol. 231:53–62, 1997. © 1997 Wiley-Liss, Inc.     

Relation between the ellipsis and the horizontal skull contour in man and various primates

The values of the human skull circumference measured in the plane of its greatest length and that of the ellipsis determinated by the semiaxis a, the half largest length of the skull, and the semiaxis b, the half largest breadth, prove a high correlation which is neither dependent on the skull form nor size. The difference between the circumference of the skull and the ellipsis amount only a few % and correlates to the skull form. The areas of intersection of the skull and the area of the ellipsis correspond entirely. Samples of non-human primates show the skull in all Haplorhini being also adjustet to the area of the ellipsis, but the correlation is not so good as in human objects and is depending on the species. The morphological difference is caused by the skull contour-lines passing under and over the ellipsis to the same amount without changing the quantitative ratio of the skull area to the ellipsis area.