W. Seeger – författare

The traditional education of the neurosurgeon and duce simultaneous contrast preparations of the ar­ the clinician working in related specialties is based teries and veins and thus obtain a complex photo­ on their presumed knowledge of the macroscopic graphic representation of the structures of the prep­ anatomy of the brain as traditionally taught. Most aration. neurosurgical textbooks, therefore, provide macro­ The manuscript and drawings were completed in the scopic views of sections of the operative site. The years 1974-1976 after almost two decades of neu­ literature that has accumulated in recent years on rosurgical work. The data worked out in the early the subject of microneurosurgical operations also stages (Chapter 1 in particular) were used by the follows this principle. author as the basis for teaching programmes at the For some years, however, the customary macro­ University of Giessen. Chapters 2-7, dealing with scopic representation of the anatomy of the brain the operative technical aspects, were produced after has been inadequate for the needs of the neurosur­ mid-1975 and used by the author as the basis for geon using refined modern operative techniques. microneurosurgical teaching of his colleagues at the Furthermore, despite their detailed presentation, University of Freiburg. stereotactic atlases are also insufficient for neuro­ My thanks are due to Doz. Dr. E.

Preface In the present volume various approaches to the same in relation to the surrounding brain structures and target area in the deep regions of the brain are cerebral vessels. Here it is to be noted that the so- described. In the previous volumes this aspect was called "quadrigeminal" region consists not only of the taken little into account. The author endeavored to Cisterna tecti, but the nearby fissures (Fissura trans- describe particularly the typical operative approaches versa cerebri and Fissura horizontalis cere belli) and their principles to make it easier for the beginner should also be included. The pathological processes to learn the microsurgical techniques in interventions do not generally confine themselves to the Cisterna in the central nervous system. tecti, but extend over the neighboring fissures. The Now problematical processes in the immediate vicini- Cisterna tecti extends without limits into the neigh- ty of the brainstem area have been exclusively boring fissures and into the Cisterna ambiens. selected.They have been separated into dorsal, later- As previously, besides personal operational experi- ences (which are not marked as such) also interven- al and ventral processes with locations mainly in the dorsal, lateral or ventral cisternal areas. Each of tions are presented which have been carried out by these three groups has been separated again into co-workers.

In the previous volume, "Differential Approaches in - if approach is hindered through such variants, or - if the lesion itself has a close relationship to impor- Microsurgery of the Brain", the particularly prob­ lematical operations in the depth of the brain around tant vessels, for example, if arteries penetrate or the brainstem were covered. Even more than in other are just adjacent to a meningioma. operations on the brain, it was important here to decide before the operation which from several pos­ On the basis of this method, it was obvious to first sible approaches would be chosen. Therefore in this present the description of the veins and then to con­ present volume, it was obvious to try to describe sider the arteries and not to choose the direction of microsurgical operations of the brain primarily under the blood flow in the image analysis, as is usually the aspect of preoperative planning. This is done by done. Only then can one judge which problems might presenting the usual daily preliminary discussions be encountered. Certainly only a part of the suspected which have taken place in the Freiburg Clinic for the problems will show up during the operation. How­ last ten years. On the day before surgery, these ever, in view of the great number of possible difficul­ discussions are always carried out according to the ties, one should also be prepared for rare complica­ same principle: tions.

A description of cerebral veins under operative­ versely, where there are large arterial vessel stems (at the base of the brain) the veins somewhat lose their technical aspects is practically a description of opera­ significance. They become important again in the tive approaches and their obstruction by cerebral region of the basal Dura, the Tentorium, and the Falx veins. It is this which constitutes the major difference but (with the exception of the region of the Sinus between arteries and veins. The arteries of the brain originate from only four large vessel stems, which cavernosus) away from the large arterial stems. This justifies writing a microneurosurgical textbook exclu­ bridge the CSF space and then run along the surface sively under the aspect of the cerebral veins. of the brain or inside the brain. Arterial vessels hardly interfere with operative approaches, even in the deep That we know so much about cerebral veins is due CSF spaces such as the Sylvian fissure, the Tentorium primarily to the work of neuroradiologists. It is not fissure, and the ventricle system. Veins, on the other the objective of the present volume to provide a hand, can appear in almost every location of the brain compreherisive and comparative survey of the large as so-called bridging veins. They are extremely vari­ number of individual results of attempts at establish­ able and can bloc~ the approach to deep CSF spaces ing vein types.