0000000000017546
AUTHOR
Georg Fries
showing 21 related works from this author
Brain Oedema and Intracranial Pressure in Superior Sagittal Sinus Balloon Occlusion. An Experimental Study in Pigs
1990
About 2/3 of all patients with thrombosis of the superior sagittal sinus (SSS) develop signs of increased ICP and/or brain oedema (BE). The time of onset and the spectrum of symptoms in SSS thrombosis vary extremely. This variability might be caused by differences in pathomechanism like BE and rise of ICP, parameters studied in the present contribution.
Endoscope-assisted Brain Surgery: Part 1—Evolution, Basic Concept, and Current Technique
1998
Rationale The evolution of neurosurgical techniques indicates the effort to reduce surgery-related traumatization of patients. The reduction of traumatization contributes to better postoperative outcomes. The improvement of diagnostic imaging techniques facilitates not only the precise localization of lesions but also the accurate determination of topographical relations of specific lesions to individual anatomic variations of intracranial structures. This precision of diagnostic imaging should be used to perform individual surgical procedures through so-called keyhole approaches. Keyhole craniotomies are afflicted with a reduction of light intensity in the depth of the operating field, and…
Enhanced Interleukin-1β Release and Longevity of Glioma-associated Peripheral Blood Monocytes in Vitro
1994
Interleukin-1 (IL-1) plays a controversial role in the immune response. Besides its activation of immune cells and juvenile central nervous system cells, monocyte-derived IL-1 may be able to stimulate the malignant transformation and proliferation of glial brain tumor cells expressing IL-1 receptors. The aim of this study was to determine the growth pattern and the IL-1 beta release of long-term cultured peripheral blood monocytes of glioma patients. At 6- to 7-day intervals, the vital monocytes, characterized by CD14 immunophenotyping, were counted. By the use of a specific IL-1 beta enzyme-linked immunosorbent assay, the IL-1 beta content of monocyte culture supernatants derived from 13 s…
Transcranial Doppler diagnosis of cerebral vasospasm following subarachnoid haemorrhage: correlation and analysis of results in relation to the age o…
1994
A retrospective analysis was undertaken to determine whether cerebral vasospasm following subarachnoid haemorrhage (SAH) correlates with the age of patients. For at least 3 weeks after bleeding 80 subjects underwent very close follow-up with clinical examination and transcranial Doppler records of the blood velocities within the basal cerebral arteries. Firstly a correlation between measured maximal mean blood flow velocities and age was made. Secondly, according to their age and the maximum of recorded mean velocities (v), the patients were divided into groups as follows: age 55 years or less, age more than 55 years; and maximum velocity v190 cm/s, 90 cm/sv2120 cm/s, 120 cm/sv3160 cm/s, v4…
Experimental Hypertensive Intracerebral Mass Hemorrhage in Cats
1986
About two–thirds of all patients with spontaneous intracerebral hemorrhage suffer from systemic hypertension. Additionally systemic hypertension is the main factor indicating a poor prognosis of intracerebral hemorrhage. This has been shown in our statistical evaluation of 117 cases of conservatively treated spontaneous intracerebral hemorrhage. More than 48% of the hypertensive patients died, but only 30% of the normotensive patients (Fig. 1). In an experimental study we investigated the influence of systemic hypertension and normotension on epidural pressure and on the formation of brain edema during the first 12 h after artificial intracerebral hemorrhage.
Neuroendoscopic Technique for the Operative Treatment of Septated Syringomyelia
1992
The management of septated, chambered syringomyelia has until now been problematic because the usual operative methods cannot secure drainage of all chambers of the cavity.
Contralateral and ipsilateral microsurgical approaches to carotid-ophthalmic aneurysms.
1997
Objective The vicinity of carotid-ophthalmic aneurysms to the roof of the cavernous sinus, to the anterior clinoid process, and to the optic nerve or the optic chiasm requires well-defined surgical techniques. Although microsurgical techniques with ipsilateral direct approaches to these aneurysms have been described in detail, studies about contralateral strategies for the microsurgical treatment of carotid-ophthalmic aneurysms are rare and are mainly confined to case reports. The aim of this study is to describe how to decide on the ipsilateral and contralateral microsurgical approaches to such aneurysms and to demonstrate the surgical techniques for the ipsilateral and contralateral expos…
Cerebral blood flow velocities after subarachnoid haemorrhage in relation to the amount of blood clots in the initial computed tomography.
1998
In 72 patients with acute subarachnoid haemorrhage (SAH) the relationship between the amount of subarachnoid blood clots detected by initial cranial computed tomography (CCT) up to 48 hours after bleeding and the later development of vasospasm, established by blood flow velocity measurement with transcranial Doppler ultrasound (TCD) was investigated. The serial Doppler examinations started within the first 72 hours after SAH and were carried out every second day up to three weeks. Each Doppler recording was accompanied by a neurological examination. Patients classified as Hunt and Hess grade V were excluded from the study. All patients with remarkable brain oedema in CCT or with intracrania…
Occlusion of the pig superior sagittal sinus, bridging and cortical veins: multistep evolution of sinus-vein thrombosis
1992
✓ Cerebral sinus-vein thrombosis may lead to severe hemodynamic changes, elevated intracranial pressure (ICP), and brain edema. It is supposed that progression of the thrombus from the sinus into bridging and cortical veins plays a key role in the development of these pathophysiological changes, but this hypothesis lacks experimental proof. The aim of this study, using a novel animal model of sinus-vein thrombosis, was to evaluate the effects of a standardized occlusion of the superior sagittal sinus and its bridging and cortical veins on hemodynamic alterations, on brain water content, and on ICP in domestic pigs. In 10 animals, the middle third of the superior sagittal sinus was occluded …
Endoscope-assisted Brain Surgery: Part 2—Analysis of 380 Procedures
1998
Objectives Microsurgical techniques and instruments that help to reduce intraoperative retraction of normal intracranial neuronal and vascular structures contribute to improved postoperative results. To achieve sufficient control of the operating field without retraction of neurovascular components, the resection of dura and bone edges is frequently required, which, on the other hand, increases operating time and operation-related trauma. The use of endoscopes may help to reduce retraction and, at the same time, may help to avoid additional dura and bone resection. The aim of this study is to describe the principles on which the technique of endoscope-assisted brain surgery is based, to giv…
Suprasellar Granular Cell Tumor
1992
A case of a suprasellar granular cell tumor, approximately 1.5 cm in diameter, in a 68-year-old woman is described. Diagnosis was established postoperatively by histopathological examination of the tumor tissue. The preoperative computed tomographic scan revealed a slightly hyperdense suprasellar mass with strong contrast enhancement. There was no evidence of calcification. The T1-weighted image on magnetic resonance imaging scan showed an isointense tumor with non-homogeneous enhancement after intravenous gadolinium diethylene-triamine-pentaacetic acid. In the proton-weighted image, the suprasellar mass presented a non-homogeneously enhanced signal. A non-homogeneous signal reduction was s…
The keyhole concept in aneurysm surgery: results of the past 20 years.
2011
Item does not contain fulltext BACKGROUND: Improvements in preoperative imaging and intraoperative visualization have led to a refinement in surgical techniques. OBJECTIVE: Report of a 20-year experience with application of the keyhole technique as a contribution to the ongoing debate on the impact of limited craniotomies in aneurysm surgery. METHODS: Over a 20-year period, 1000 consecutive patients with 1297 aneurysms were surgically treated in 1062 operations: 651 in the acute stage after SAH and 411 with unruptured aneurysms. The outcome was assessed with the modified Rankin scale and approach-related complications. RESULTS: The majority of the cases were treated by 4 different keyhole a…
Endoscope-assisted keyhole surgery for aneurysms of the anterior circulation and the basilar apex
2000
In the treatment of cerebral aneurysms, preoperative surgical planning and intraoperative strategies for microsurgical approaches are important issues. Within the context of minimally invasive neurosurgery, so-called keyhole approaches, especially those with intraoperative endoscopic assistance, have gained increasing interest, but their application for cerebral aneurysm surgery is a matter of ongoing controversy. The main aspects of keyhole microsurgery, with and without endoscopic assistance, for cerebral aneurysms are explained. To present the keyhole concept, which is based on the preoperative analysis and intraoperative use of pre-existing anatomic windows, this article concentrates on…
Tissue characterization of benign brain tumors: Use of NMR-tissue parameters
1988
Abstract To evaluate the potentials of NMR tissue parameters for tissue characterization we investigated 68 patients with benign brain tumors. Tissue parameters were accurately measured by a recently developed interlaced triple sequence. Each individual tumor was characterized by a set of three numbers (relaxation times T 1 and T 2 and proton density Rho). Different tumors exhibited significant overlaps of the three tissue parameters. Therefore a reliable prediction of the histological diagnosis based on the quantitative analysis of tissue parameters alone was not possible. T 2 -prolongation correlated well with water content and “regressive changes” in meningiomas and neuromas.
The Influence of Systemic Hypertension on Intracranial Pressure and Edema Formation in Experimental Intracerebral Hemorrhage
1986
Systemic hypertension is not only the most frequent cause of intracerebral hemorrhage but also the most important complication of this disease. In our clinical investigation of 117 cases almost 70% of the patients suffered from systemic hypertension. Despite advances in diagnosis (Schiirmann, Dei Anang, 1980) mortality of hypertensive patients was 48%. Normotensive hemorrhages showed a better prognosis: only 31% of the patients died and 33% (17% in hypertensive patients) obtained good neurological recovery (Wallenfang et al., 1985).
Evaluation of collateral flow capacity in patients with vascular or tumorous lesions of the skull base by Doppler sonography
1991
In 12 patients with vascular or tumorous lesions of the skull base, the collateral flow capacity was examined by transcranial Doppler sonography and carotid compression studies. In four patients no cross flow mechanism was found, in two patients the test remained unclear, and in six patients the examination suggested a good collateral flow capacity. However, for this application of Doppler sonography no borderlines have yet been defined and thus interpretation is difficult. Intraoperative Doppler sonography was used in five patients and proved to be helpful for localisation of the internal carotid artery within skull base tumors.
Meningiomas of the Space of the Cavernous Sinus
1996
During the years 1985 to 1992, we encountered 59 patients with meningiomas involving the space of the cavernous sinus. In 29 of these patients, meningiomas were primarily located within the space of the cavernous sinus and were operated on without mortality and with low morbidity. A small subtemporal surgical approach was favored, which allowed initial tumor resection from the posterior aspect, where the Parkinson's triangle is wide, thus avoiding the additional morbidity of large-scale approaches. According to the relationships of the all-important cranial nerves passing within the lateral wall of the cavernous sinus, we divided the primary intracavernous meningiomas into four types, which…
Endoscopic Third Ventriculostomy: Outcome Analysis of 100 Consecutive Procedures
1999
OBJECTIVE: Endoscopic third ventriculostomy (ETV) has been shown to be a sufficient alternative in the surgical treatment of occlusive hydrocephalus. To elucidate the ongoing discussion of timing, indication, and surgical technique, a retrospective analysis of 100 consecutive ETVs was conducted. METHODS: One hundred ETVs were performed in 95 patients (43 female and 52 male patients). Their age ranged from 3 weeks to 77 years (mean age, 36 yr). Hydrocephalus was caused by aqueductal stenosis in 40 patients, space-occupying lesions in 42, and intraventricular or subarachnoid hemorrhage in 8. One patient had postinflammatory hydrocephalus, and four patients had occlusive hydrocephalus of unkno…
Use of a new aneurysm clip with an inverted-spring mechanism to facilitate visual control during clip application. Technical note.
1995
✓ When operating on deep-seated cerebral aneurysms, the surgeon's visual control of clip application may be impaired by the clip holder unless adjacent structures are retracted. To improve visual control and reduce the necessity for retraction, the senior author (A.P.) developed a new concept: an aneurysm clip with an inverted-spring mechanism. The clip has two jaws that point away from the clip blades. The jaws of the clip holder articulate with the inner side of the clip jaws. By distending the jaws of the clip holder the blades of the clip are opened and vice versa. Thus the visual field increases while the clip application is proceeding. This instrumentation is useful, especially in cas…
Immunohistochemical Investigation in Experimental Intracerebral Hemorrhage (ICH) and Its Correlation with Findings in Clinical Studies
1986
Since McKissock et al. 1961 investigated the effects of surgical and conservative treatment of ICH on final outcome it is well known that systemic hypertension worsens the prognosis of this serious cerebrovascular disease. Our own studies on this problem have revealed differences in final outcome, as well as in level of consciousness after ICH, between normotensive and hypertensive patients. Whilst 30.6% of the normotensive patients died, 48.1% of the hypertensive patients had a lethal outcome.
Glioblastoma-associated circulating monocytes and the release of epidermal growth factor.
1996
✓ Monocytes/macrophages frequently infiltrate malignant gliomas and play a central role in the tumor-associated immune response as they process tumor antigen and present it to T-lymphocytes. Findings have accumulated that peripheral blood monocytes leaving the cerebral circulation become microglial cells and vice versa and that monocytes/macrophages may stimulate malignant tumor growth by some unknown mechanism. Most malignant gliomas express growth factor receptors, for example epidermal growth factor receptor (EGFR). The aim of this study was to determine whether peripheral blood monocytes of glioma patients release EGF, the appropriate ligand of gliomacell membrane-bound EGFR. Long-term …