A. Perneczky

Direct surgical approach to infraclinoidal aneurysms

SummaryA loose connective tissue layer covering the intracavernous portion of the internal carotid artery makes the exposure of the anterior syphon knee possible without opening the cavernous sinus. The approach leads by a fronto-latero-basal craniotomy to the anterior part of the cavernous sinus roof (transversal plate). The anatomical relationships are discussed. By means of surgical cases, both the ipsilateral and the contralateral approach to infraclinoidal aneurysms are demonstrated.

Cavernous sinus surgery

SummaryThe cavernous sinus is divided from the surgical point of view into three parts. The middle part consists of the lateral sinus wall, the cranial nerves III, IV, V, VI and the posterior siphonknee of the internal carotid artery. Lesions of this region, vascular as well as tumorous, can be exposed by approaching the lateral sinus wall. The surgical dissection through the sinus wall is based on some important anatomical details, which are described here. As a consequence a modified transcavernous approach will be introduced and demonstrated by 35 clinical cases.

Intradural variant of cervical nerve root fibres. Potential cause of misinterpreting the segmental location of cervical disc prolpases from clinical evidence.

SummaryIn 40 postmortem specimens the cervical posterior roots were examined under the surgical microscope, and intradural communicating fibres between neighbouring segments were demonstrated. The implications of these frequent variants for the diagnosis of prolapsed cervical discs are discussed.

Problems of Surgical Technique for the Treatment of Supratentorial Midline Tumors in Children

In this presentation the authors describe briefly their thoughts on microsurgical management of certain typical brain tumors arising from within and adjacent to the third ventricle the surgical treatment of which has for many years been essentially conservative, not infrequently without histological verification of the type of the tumor or even of the presence of a real neoplasm.

Timing of surgery for ruptured aneurysms--experience from 800 consecutive cases.

SummaryIn the Department of Neurosurgery, University of Vienna, about 800 patients with intracranial aneurysms have been operated since 1958. The distribution of age, sex, and the localization of the aneurysms correspond roughly to the international statistics. From our experience it is apparent that the level of consciousness and responsiveness is the most important factor in deciding the choice and time of treatment on the one hand and the further fate of the patient on the other. The authors therefore use some modification of the five-grade system of Hunt and Hess to stress the importance of the level of consciousness and the neurological deficits.As far as timing of surgery is concerned, the earliest possible microsurgical treatment for patients in grades I and II seems the method of choice, primarily to avoid rebleeding. Patients with impaired and/or fluctuating consciousness, neurological deficits and rather severe signs of meningeal irritation were operated as soon as the clinical picture became stable or showed a tendency to improve. Grade V patients were operated only if a life-threatening space occupying intracerebral haematoma was encountered my means of a CT scan. Nevertheless the authors have tried to avoid any too rigid routine and to adjust their decisions on therapeutic measurements according to the needs of the individual patient.

Para- and infraclinoidal aneurysms. Anatomy, surgical technique and report on 22 cases

The internal carotid artery in its intracavernous portion is covered by a soft connective tissue layer. At the entrance of the artery into the subarachnoid space there is a very dense fibrous ring fixing the artery wall at the roof of the cavernous sinus. After cutting the fibrous ring it is possible to dissect along the artery wall without opening the cavernous sinus. The anatomical details are described.

Intraventricular aneurysm of the medial posterior choroid artery clipped via the contralateral transcallosal approach

SummaryIn lesions located in the lateral ventricle of the dominant hemisphere the contralateral transcallosal approach provides maximum protection of the dominant side as well as excellent visualization of the cella media of the contralateral lateral ventricle. We demonstrated this safe approach in a rare case with intraventricular aneurysm of the left medial choroid artery. The literature on aneurysms in the lateral ventricle is discussed.

Blood Supply of Acoustic Neurinomas

SummaryThe arterial blood supply of acoustic neurinomas is reviewed on the basis of normal and pathological anatomical findings as well as neuroradiological and intra-operative observations. Available data suggest that, as a rule, the tumour primarily receives blood from the external carotid by way of dural vessels, with the occipital artery playing a prominent role. The cerebellar vessels, including the anterior inferior cerebellar artery, are apparently no more than secondary contributors. In the light of these observations, selective external carotid angiography on the diseased side is recommended in acoustic neurinomas. In hypervascularized neurinomas preoperative embolization of afferent external carotid branches is discussed as a potential supplementary procedure.

The relationship between the caudolateral pontine syndrome and the anterior inferior cerebellar artery.

SummaryThe caudolateral pontine syndrome associated with compromised circulation through the anterior inferior cerebellar artery is reviewed on the basis of three cases. Clinical observations are supplemented by the authors anatomical studies, and the pertinent literature is discussed.

Special remarks on microsurgical techniques for cerebral aneurysms

SummaryReviewing 152 cases of intracranial aneurysms which have been operated under identical preoperative, intraoperative and postoperative surgical conditions, the authors discuss the role of the microsurgical technique for prevention of postoperative vasospasm and for positively influencing the symptoms caused by subarachnoid haemorrhage.