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Helmut Bertalanffy

Publications and source records attributed to Helmut Bertalanffy.

At least 37 records · Page 2Linked to original sources

Surgical closure and reconstruction of a large occipital encephalocele without parenchymal excision.

INTRODUCTION: Encephalomeningocele is a herniation of the brain and meninges through a congenital bone defect resulting from the failure of normal midline fusion of the cranial neural tube. Various sites are possible; however, among Caucasians more than 70% of encephaloceles are located on the occipital/posterior part of the cranium. Usually they contain degenerative cerebral cortex, which is often excised during surgical closure of the defect. Techniques to preserve the herniated brain tissue have been described, but they focus on increasing the intracranial cavity by ventriculomegaly and retracting the encephalocele into new intracranial space in a second stage, as a result of hydrocephalic treatment. TECHNICAL REPORT: The authors report a well-documented newborn with a large encephalocystocele of the left occipital lobe. This encephalocele included the left lateral ventricle and a part of the cerebellum, and was covered with allopathic skin. Initially the cystic portion was removed so that a partial reduction of the encephalocystocele was achieved. Six months later, the surgical closure of the defect was performed, with preservation of the occipital and cerebellar parenchyma, by incising the tentorium and retracting the cortex to the newly created infratentorial space. The bony defect was covered with autologous osseous graft harvested from parietal bone and reconstructed. OUTCOME: In the long-term follow-up after 13 years, the child has preserved visual function.

Child↗

The evolution of stereotactic guidance in neuroendoscopy.

OBJECTIVES: To evaluate the advantages and limitations of the utilized system in accordance with the operative indications of stereotactic neuroendoscopy. PATIENTS AND METHODS: We reviewed our collective experience of computer-assisted stereotaxy (frame-based and frameless) and virtual endoscopy in neuroendoscopic surgery from 1982 to 2003. Sterotactic guiding systems (frame-based and frameless) have been used to perform more than 450 neuroendoscopic operations at our institute. RESULTS: Even though image guidance is not essential in all cases, technological developments have definitely been one of the major factors in improving outcomes. Planning endoscopic trajectory and intraoperative orientation within the ventricular system or other cavities are the main indications for its application. CONCLUSIONS: No surgical tool, no matter how accurate, can be a substitute for thoughtful and methodical pre-operative planning. Image-guided technologies are applied in order to make endoscopic surgery safer, faster and more easily reproducible. Despite the high initial cost of the equipment, overall expenses are expected to be reduced because of greater operative efficiency and shorter hospital stay.

Adolescent↗

Neuroendoscopic surgery of intracranial cysts in adults.

OBJECTS: The purpose of this study was to describe the indications, surgical techniques and postoperative outcome of neuroendoscopic interventions in a heterogeneous group of intracranial cystic pathologies. PATIENTS AND METHODS: Between 1992 and 2003, 127 patients with symptomatic intracranial cysts and cystic tumours underwent neuroendoscopic treatment in our department. In 22 patients indication for surgery was colloid cysts, in 9 patients pineal cysts and in 3 patients cavum vergae cysts. Twelve arachnoid cysts, 10 cystic craniopharyngiomas, 2 Rathke's cleft cysts and 69 malignant cystic tumours were operated on. The patients' mean age was 45 years and their clinical presentations varied from typical signs of increased intracranial pressure to focal neurological deficits. RESULTS: One hundred and twenty-seven patients with intracerebral cystic space-occupying lesions were operated on using stereotactic frameless or frame-based endoscopic techniques. There was no operative mortality. The operative morbidity was 3.1% including 1 memory deficit due to fornix injury, 1 hemiparesis due to postoperative haematoma after lesion biopsy, 1 aseptic meningitis and 1 subdural fluid collection. CONCLUSIONS: Endoscopic interventions enable neurosurgeons to manage intracranial cystic lesions. Via the same approach, the obstructed CSF pathways may be restored and consequently the increased intracranial pressure diminishes. With the aid of stereotactic guidance or a neuronavigation system, access to the lesion can be gained rapidly and with high accuracy.

Adult↗

Neuroendoscopic stent procedure in obstructive hydrocephalus due to both foramina of monro occluding craniopharyngioma: technical note.

BACKGROUND: The development of various neuroendoscopic surgical instruments has offered more options for endoscopic procedures in the treatment of intraventricular tumors. Not only tumor biopsy or tumor resection but also restoration of an obstructed cerebral spinal fluid (CSF) pathway can be performed using the same approach. METHOD: A 76-year-old woman with a cardiac pacemaker for an underlying heart disease was diagnosed with obstructive hydrocephalus because of a third ventricular tumor 8 years ago. The patient had been treated with ventriculo-peritoneal shunt placement. At admission she presented with a subcutaneous infection of the shunt catheter and an abdominal mass of unknown etiology. Neuroendoscopic stenting between lateral and third ventricle was performed to restore the obstructed CSF pathway, and the infected shunt system was removed in the same setting. RESULT: The postoperative course was uneventful. Contrast ventriculography demonstrated a restored CSF pathway between the lateral and third ventricle. Histologic examination of the intraventricular tumor revealed a craniopharyngioma, and the abdominal mass was diagnosed as a gastrointestinal adenocarcinoma. CONCLUSION: The neuroendoscopic foraminoplasty technique should be considered as an alternative treatment for patients who present with an obstructive hydrocephalus caused by a tumor that occludes both foramina of Monro when shunt placement or endoscopic third ventriculostomy is not feasible.

Adenocarcinoma↗

Hypoxia-inducible factor and vascular endothelial growth factor are expressed more frequently in embolized than in nonembolized cerebral arteriovenous malformations.

OBJECTIVE: In previous studies, we documented a marked neoangiogenesis and endothelial proliferation in cerebral arteriovenous malformations (AVMs) that were embolized before surgery compared with those that were not embolized. We hypothesized that embolization caused a local hypoxia that promotes neoangiogenesis as a possible pathomechanism. To support this hypothesis, we now examined the angiogenesis-related proteins in a larger cohort of patients. In addition, we investigated hypoxia-inducible factor-1 alpha as a possible protein operative during neoangiogenesis of cerebral AVMs. METHODS: Paraffin-embedded specimens of 56 AVMs obtained from surgical resection and 14 brain tissue controls were immunohistochemically stained with antibodies to proliferating cell nuclear antigen, MIB-1, vascular endothelial growth factor, Flk1, and hypoxia-inducible factor-1 alpha by standard protocols. RESULTS: In AVMs treated with embolization before surgery (n = 35, 63%), the expression of hypoxia-inducible factor-1 alpha (P = 0.0101) and vascular endothelial growth factor (P = 0.0007) was significantly higher (Fisher's exact test) than in patients who did not have previous endovascular treatment. Differences in the expression of Flk-1 (P = 0.0798) and proliferating cell nuclear antigen (P = 0.0423) were in the same direction but were not significant when corrected for multiple testing. CONCLUSION: Our results provide circumstantial evidence that a partial occlusion of cerebral AVMs might induce local hypoxia-related neoangiogenesis. To support these data, future animal studies should be performed.

Adolescent↗

Arteriovenous malformation surrounding the trigeminal nerve--case report.

A 57-year-old man presented with subarachnoid hemorrhage due to the rupture of an arteriovenous malformation (AVM) located at the base of the root of the right trigeminal nerve. In contrast to previous similar cases, his history included no evidence of trigeminal neuralgia or sensory loss. Right vertebral artery angiography revealed a doubled superior cerebellar artery feeding the angioma nidus. The patient refused radiotherapy and preferred surgical treatment. Intraoperatively, a close relationship between arterial feeders and rootlets of the trigeminal nerve was observed. Complete removal of the malformation was achieved and confirmed angiographically. The postoperative course was complicated by subdural hygroma that required repeated drainage and eventually a shunting procedure. This case demonstrates that microsurgical treatment of a trigeminal AVM is feasible. However, stereotactic radiosurgery may be the preferred treatment option considering the potential for postoperative complications.

Humans↗

Immunohistochemical study in dural arteriovenous fistula and possible role of ephrin-B2 for development of dural arteriovenous fistula.

BACKGROUND: Although there were several clinical and experimental studies discussing the pathogenesis of dural arteriovenous fistula (DAVF), the pathological process leading to intracranial DAVF so far remains unknown. In this study, we investigated the expression of vascular growth factors in order to elucidate the possible role of these factors for the development of DAVF and to study the biological activity of this uncommon lesion. METHODS: We examined the histological features, proliferative and angiogenic capacities of the tissue specimens obtained from 6 patients who underwent surgery at our institution. Immunohistochemical staining for vascular endothelial growth factor (VEGF), its receptors Flk-1 and Flt-1, ephrin-B2, MIB-1 and proliferating cell nuclear antigen (PCNA) was performed using standard immunohistochemical techniques. RESULTS: A positive immunostaining was found for all antibodies studied except MIB-1, whereas nuclear endothelial expression of PCNA was observed in only 3/6 cases. VEGF stained positive in all of the available specimens (6/6). Flk-1 showed a positive immunoreaction in only 2/6 cases and Flt-1 in 4/6 cases. Ephrin-B2 was expressed in the majority (5/6) of the cases. CONCLUSIONS: These results support the hypothesis that DAVFs might be acquired dynamic vascular malformations with low biological activity. Vascular growth factors like VEGF and ephrin-B2 might play a pivotal role in the formation of DAVF.

Aged↗

Isolated paramedullary hemangioblastoma originating from the first cervical nerve root: case report.

STUDY DESIGN: A retrospective case of an isolated paramedullary hemangioblastoma originating from the first cervical root is reported. OBJECTIVE: To describe an uncommon type of spinal hemangioblastoma and its operative treatment. SUMMARY OF BACKGROUND DATA: Spinal hemangioblastoma, rare finding accounting for approximately 1.5% to 2.5% of all spinal cord tumors, may have an intramedullary, extramedullary, or extradural location. Cervical hemangioblastomas occur in approximately 45% of the cases and are intramedullary in about 83% of the cases. METHODS: A 59-year-old man presented with acute subarachnoid hemorrhage in the basal cisterns. Four-vessel angiography showed a highly vascular small tumor at the dorsolateral side of the cervicomedullary junction fed by a branch of the vertebral artery. The lesion was surgically removed. RESULTS: Total removal of the lesion was achieved after identification of both the arterial feeder and the draining vein with the aid of microvascular Doppler sonography. There were no complications, and the patient did well after surgery. CONCLUSIONS: Although hemangioblastomas occurring in the cervicomedullary area usually may cause progressive neural compression, occasionally they also can present clinically as acute subarachnoid hemorrhage. This situation requires urgent and adequate treatment as in the reported case.

Acute Disease↗

Neuroendoscopic treatment for colloid cysts of the third ventricle: the experience of a decade.

OBJECTIVE: Microsurgical resection or ventriculoperitoneal shunt placement was for a long time the only means of treatment for patients with colloid cysts. In the past few years, however, endoscopic procedures have gained increasing significance and have been used more widely. Long-term results are now available for the first time, which enabled us to evaluate this method and assess its future relevance. METHODS: Twenty patients with symptomatic colloid cysts of the third ventricle have been treated endoscopically in our department during the past 10 years. Retrospective analysis and follow-up of the patients' clinical and radiological outcomes were performed. RESULTS: In the early postoperative period, 18 patients had excellent outcomes, with clinical signs improving immediately. One patient experienced intraoperative hemorrhage followed by temporary postoperative psychosis and IIIrd cranial nerve palsy. Another patient remained shunt-dependent because of aseptic meningitis after the endoscopic procedure. In the long-term follow-up, one patient had to be reoperated to treat cyst recurrence. The operative time was strongly dependent on the cyst material as well as on the surgeon's experience with endoscopic techniques; it varied between 60 and 300 minutes (mean operative time, 200 min). The average hospitalization time was 9 days. Long-term follow-up ranging from 1 to 10 years showed a clear benefit in each patient. In three individuals with pre- and postoperative short-term memory deficits and in one patient who complained of headaches, symptoms resolved gradually during the first few months after surgery. The patient with intraoperative hemorrhage complained of slight permanent short-time memory deficit. The analysis of postoperative computed tomographic and magnetic resonance imaging scans revealed a remaining cyst wall in the majority of patients and an inconsistent decrease in ventricular size. Postoperative cine magnetic resonance imaging studies showed normalization of cerebrospinal fluid flow in 17 patients. CONCLUSION: Continued improvement of endoscopic techniques and instruments, together with good long-term results in endoscopically treated patients, have established this method as an alternative to microsurgical techniques and might even set a new standard for treatment.

Adolescent↗

Intraoperative spinal digital subtraction angiography: technique and results.

OBJECTIVE: To evaluate technical and methodological aspects of intraoperative spinal digital subtraction angiography (ISDSA) in our clinical practice and to assess its practicability, safety, and accuracy for the surgical treatment of spinal vascular malformations. METHODS: Between August 1997 and February 2002, a total of 30 patients were treated either surgically (n = 18) or endovascularly (n = 12) for spinal vascular lesions at our institution. The clinical records of five patients who underwent ISDSA were analyzed retrospectively. The thoracic segment was involved in three patients and the medullary cone in two. RESULTS: ISDSA could be performed in four cases. In one patient, the segmental artery could not be probed sufficiently while the patient was prone. No complications occurred from the application of ISDSA. The method was beneficial for the neurosurgeon in all but one patient because the vascular anatomy of the malformation was shown with respect to the surgical approach, including the nidus, and immediate resection control could be performed before wound closure. The duration of the procedure was prolonged by 45 minutes on average. CONCLUSION: ISDSA is safe and effective, especially in surgery for complex vascular and recurrent malformations. Benefits to the patient outweigh the additional expense and prolongation of the surgical procedure.

Adolescent↗

Image-guided transsylvian, transinsular approach for insular cavernous angiomas.

OBJECTIVE: Surgical treatment of cavernomas arising in the insula is especially challenging because of the proximity to the internal capsule and lenticulostriate arteries. We present our technique of image guidance for operations on insular cavernomas and assess its clinical usefulness. METHODS: Between 1997 and 2003, with the guidance of a frameless stereotactic system (BrainLab AG, Munich, Germany), we operated on eight patients who harbored an insular cavernoma. Neuronavigation was used for 1) accurate planning of the craniotomy, 2) identification of the distal sylvian fissure, and, finally, 3) finding the exact site for insular corticotomy. Postoperative clinical and neuroradiological evaluations were performed in each patient. RESULTS: The navigation system worked properly in all eight neurosurgical patients. Exact planning of the approach and determination of the ideal trajectory of dissection toward the cavernoma was possible in every patient. All cavernomas were readily identified and completely removed by use of microsurgical techniques. No surgical complications occurred, and the postoperative course was uneventful in all patients. CONCLUSION: Image guidance during surgery for insular cavernomas provides high accuracy for lesion targeting and permits excellent anatomic orientation. Accordingly, safe exposure can be obtained because of a tailored dissection of the sylvian fissure and minimal insular corticotomy.

Adult↗

Pontine hemorrhage.

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Cerebral Hemorrhage↗

Successful management of a symptomatic fusiform dilatation of the internal carotid artery following surgery of childhood craniopharyngioma.

INTRODUCTION: The development of fusiform dilatation of internal carotid artery is one of the vascular complications that can follow surgery for craniopharyngioma and other suprasellar tumours in children, but its pathogenesis and the line of management are still controversial. CASE REPORT AND DISCUSSION: We report a child who presented with a giant fusiform aneurysm involving the supraclinoid portion of the internal carotid artery after total removal of a craniopharyngioma and review the literature on related cases. The treatment of this phenomenon and its possible pathogenesis are discussed.

Aneurysm↗

Cerebral cavernomas in the adult. Review of the literature and analysis of 72 surgically treated patients.

The authors review the pertinent literature dealing with all aspects of cerebral cavernous malformations in the adult. Clinical, neuroradiological, pathological, and epidemiological aspects are presented. The clinical significance of bleeding from cavernous malformations and various hemorrhage patterns are discussed in relation to the factors that influence hemorrhage rates. Recent reports describing the genetic mechanisms of inheritance, de novo formation, and angiogenesis of cavernomas are reviewed as well. Brainstem cavernomas have received special attention, since their clinical management is controversial in the literature. Presently, microsurgical removal is favored by the majority of authors and stereotactic radiosurgery appears to be inappropriate for prevention of bleeding from a cavernoma. Our own case material consists of data of 72 patients operated upon during the past 5 years. Twenty-four patients harbored the lesion within the brainstem, 18 within the deep white matter of the hemispheres, 12 in the basal ganglia or thalamus, 11 in superficial areas of the hemisphere, and seven within the cerebellum. The perioperative morbidity rate was 29.2% (21/72) while the rate of long-term morbidity was 5.5% (4/72), with no mortality in this series. It is concluded that cerebral cavernous malformations, including lesions in critical regions of the brain, can be treated microsurgically with excellent results and an acceptable morbidity.

Brain Neoplasms↗

Role of nitric oxide in the regulation of spinal arteriolar tone.

OBJECTIVE: The important role played by nitric oxide (NO) in the maintenance of cerebral arterial tone, both in the resting state and after injury, has been demonstrated, but the role of NO in spinal arteries is unknown. The aim of this study was to verify, by topical application of a NO synthase inhibitor in vivo, the hypothesis that NO plays an important role in the maintenance of spinal arteriolar tone. METHODS: Closed spinal windows were prepared at the C6 level, for observation of arteriolar reactivity. Male Wistar rats were divided into four groups in the resting state and three groups in the compressed state (which was produced by increasing the intrathecal window pressure). The control group underwent superfusion of artificial cerebrospinal fluid into the spinal window. The nitro-L-arginine-methyl ester (L-NAME) and nitro-D-arginine-methyl ester groups underwent superfusion of the NO synthase inhibitor L-NAME and its inactive enantiomer nitro-d-arginine-methyl ester, respectively. The L-NAME/S-nitroso-acetylpenicillamine (SNAP) group underwent mixed superfusion of L-NAME and the direct NO donor SNAP, for investigation of the effects of an exogenous NO donor. RESULTS: In the resting state, the arterioles constricted significantly in the L-NAME group, compared with values before L-NAME superfusion and those for the other groups. In the L-NAME/SNAP group, the arterioles dilated significantly after SNAP superfusion, compared with values before superfusion and those for the other groups. In the compressed state, the arterioles dilated after compression in all three groups but the dilation was significantly attenuated in the L-NAME group, compared with values for the control and nitro-D-arginine-methyl ester groups. CONCLUSION: It is suggested that NO plays an important role in the maintenance of spinal arteriolar tone in the resting and compressed states of the spinal cord.

Animals↗

Novel multipurpose bipolar instrument for endoscopic neurosurgery.

OBJECTIVE: Hemorrhage control in endoscopic neurosurgery is critical because of the lack of suitable instruments for coagulation. One reason for this problem is that miniaturization of the instruments is still a technical problem. In this article, we present a solution: the use of bipolar microforceps with a small diameter of 1.5 mm. METHODS: With the use of modern synthetic and metallic materials, the construction of the bipolar microforceps was designed without the use of mechanical joints. All movable elements are integrated within the instrument shaft. This design provides optimal visibility of the operating field because the sheath has a diameter of only 1.5 mm along its entire length. Therefore, this instrument is compatible with most working channels of neuroendoscopes. RESULTS: The new, joint-free design of the forceps and the electric insulation of the branches were the technical innovations that led to the development of this novel, multipurpose instrument. CONCLUSION: This new instrument may enhance endoscopic resection and shrinkage of cystic lesions and may offer new possibilities in endoscopic tumor resection and the treatment of hemorrhage.

Adult↗