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Biomedical subjects

W Burkert

Publications and source records attributed to W Burkert.

At least 37 records · Page 2Linked to original sources
PubMed1997

Prognostic factors in malignant glioma: influence of the overexpression of oncogene and tumor-suppressor gene products on survival.

Despite the use of multimodal therapy, higher-grade glioma is still uniformly fatal in the adult population. There is a considerable difference between the length of survival in each given patient, even within the same tumor type and malignancy grade group, suggesting that there are factors that might differentially influence outcome. To identify such factors, 107 patients with anaplastic or malignant glioma were retrospectively investigated. Clinical parameters and paraclinical data on the p53, mdm2, and EGFR genes at the DNA or protein level were evaluated by univariate analysis and Cox proportional hazards regression modeling. Kaplan-Meier survival estimation demonstrated that immunohistochemical positivity for mdm2 protein in patients with anaplastic astrocytoma or with glioblastoma multiforme was associated with a shorter survival time (p = 0.02). P53 gene mutations and immunopositivity for the epidermal growth factor receptor (EGFR) protein were not significantly related to poor prognosis. The Cox proportional hazards model revealed immunohistochemical positivity for p53, mdm2, or for both of them, the presence of postoperative irradiation, and the extent of surgical resection of tumor to be variables significantly associated with prolonged survival. EGFR overexpression, age over 60 years, and Karnofsky performance score below 40 points did not significantly shorten survival time. In conclusion, the present study identified immunohistochemically detected mdm2-protein overexpression as a statistically significant negative prognostic parameter in patients bearing anaplastic or malignant glioma. Association analysis of variables revealed a possible correlation between mdm2 and p53, which is also consistent with the biological interaction mode of both proteins in vivo.

Analysis of Variance↗
PubMed1997

Dorsal spondylodesis of unstable thoracolumbar fractures by a far-lateral approach to the disc.

This paper describes a modified and less traumatic approach to the thoracolumbar spine and compares it with standard techniques for instrumented spinal fusion. Ten patients with unstable fractures of the thoracolumbar spine were included in the open prospective investigation, and were treated by a surgical technique consisting of a dorsolateral approach to the injured segment, filling the disk space and the fractured vertebra with autologous bone, and transpedicular fixation with an AO internal fixator. All patients were followed for 6 to 12 months after surgery by clinical tests and spinal X-rays. Excellent short-term and long-term results were obtained. A stable bony fusion was achieved in all cases, and a minimal mean decrease of 2 degrees in the kyphosis angle was found at late follow-up. No major complications related to the procedure were encountered, and no worsening of neurological deficits occurred after surgery. In conclusion, the far-lateral approach to the thoracolumbar spine yields results which are equivalent or better than those of standard techniques. Major advantages of our procedure, as evaluated in this rather small group of patients, are selective immobilization of the injured segment without involvement of functionally intact spinal levels, no manipulations within the spinal canal boundaries, and relatively limited exposure of the spine.

Adult↗
PubMed1997

Continuous monitoring of the partial pressure of oxygen in cerebral venous blood.

OBJECTIVE: Clinical oxygen monitoring in the injured brain is somewhat difficult. However, ischemia is one of the major factors responsible for secondary tissue damage after head injury or subarachnoid hemorrhage. Therefore, the aim of the present study was to investigate the value of continuously monitoring the partial pressure of oxygen in cerebral venous blood (PcvO2) during changes in intracranial pressure (ICP). METHODS: In eight domestic pigs with Clark type probes placed in the posterior third of the superior sagittal sinus, PcvO2 was continuously registered while ICP was stepwise elevated by an inflatable balloon placed below the tentorium. Arterial blood pressure was continuously monitored, cerebral perfusion pressure (CPP) was calculated, and arterial partial carbon dioxide pressure and partial pressure of oxygen were registered intermittently. RESULTS: The mean intraparenchymal ICP before the start of balloon inflation was 5 +/- 1 mm Hg, the mean CPP was 80 +/- 15 mm Hg, and the mean PcvO2 was 36 +/- 3 mm Hg. At maximum ICP elevation, CPP decreased to 20 +/- 12 mm Hg, PcvO2 decreased to 10 +/- 6 mm Hg, and ICP increased to 90 +/- 10 mm Hg. Strong linear correlations between ICP and PcvO2 and between CPP and PcvO2 were revealed, and mean correlation coefficients of 0.89 for ICP/PcvO2 and 0.73 for CPP/PcvO2 were calculated. CONCLUSION: The present study demonstrates that polarographic PcvO2 monitoring in the superior sagittal sinus is a reliable method for the early detection of reduced CPP during ICP elevation. This technique is capable of registering the global oxygen supply and oxygen consumption of the brain. It seems superior to jugular venous oxymetry and is better suited for clinical use because of a somewhat low artifact susceptibility.

Animals↗
PubMed1997

[Thromboembolic complications in neurosurgical patients].

This study was aimed at the analysis of thromboembolic risk factors in a large and representative group of adult neurosurgical patients. Using an open retrospectively designed mode of evaluation, 3162 inpatients treated in 5 years were investigated. Thromboembolism was diagnosed clinically and confirmed be ultrasound and phlebographic tests. Thromboembolism prophylaxis included subcutaneous injection of low-molecular-weight heparin and supporting physical therapy. In the whole patient population, 2.6% deep venous thromboses and 0.7% fulminant pulmonary embolisms were diagnosed. Risk factors such as malignant disease, ischemic disease of the heart, history of thromboembolism, age over 60 years, varicosis, and immobilisation rendered patients especially prone to thromboembolic events, increasing 2- to 3-fold their respective risk and reaching for some factors the level of statistical significance. Low-molecular-weight heparin application reduced the rate of thromboembolic complications, as compared to the group without heparin prophylaxis. Wound revision because of hematoma formation was necessary in 1.1% of all cases, and heparin did not induce an increase in the rate of wound hematoma formation. We conclude that low-molecular-weight heparin prophylaxis is able to safely reduce the rate of thromboembolic events in neurosurgical patients without producing additional drug-related surgical complications.

Adult↗
PubMed1996

Local invasivity of glioblastoma multiforme with destruction of skull bone. Case report and review of the literature.

Primary tumors originating from cells of the glial lineage usually affect predominantly the white matter of the brain. Only rarely do gliomas destroy the surrounding bone by invasion of the extracellular matrix, especially without prior surgery. This paper describes the unusual case of a 66-year-old female patient with a left-sided intra- and extracranial tumor involving the temporal lobe, destroying the underlying skull base, and growing into the paranasal sinuses, orbit, and temporal bone. Biopsy revealed glioblastoma multiforme with strong GFAP positivity. Molecular biologic investigations of the p53, EGFR, and mdm2 genes showed functional inactivation of the p53 gene but no overexpression of oncogenes. Because the tumor was considered inoperable, palliative irradiation was carried out. The patient died 7 months after diagnosis. The causes of this phenomenon are discussed and the literature reviewed.

Aged↗
PubMed1996

Direct anterior fixation of odontoid fractures with a hollow spreading screw system.

Direct fixation of odontoid fractures has the advantage of preserving rotation in the atlanto-axial motion segment. Early mobilisation of patients and minor intra-operative trauma increase the value of this technique. The original screw method of Nakanishi, Magerl, and Böhler, was improved by Knöringer who designed a double-threaded screw for direct fixation of dens axis fractures. He stated that double screwing is absolutely necessary in order to prevent rotation of fragments against each other. The purpose of the present study was to describe a new single screw for direct fixation of odontoid fractures, which is easy to place into the limited space of the dens axis and which offers enough rotational stability and sufficient compression of fracture fragments. The so-called hollow spreading screw system (HSS) consists of an outer hollow screw, a spreading insert, a toothed washer, an hexagonal nut, and a protective nut. Thirty-five patients with traumatic and arthritic odontoid fractures were treated using direct internal fixation with the HSS system. In 30 cases, there was a type-II-fracture, in 3 a shallow type-III-fracture, and in 2 a type-II-fracture with pseudarthrosis formation. Pre-operative neurological deficits were seen in 16 cases. No additional neurological deficits were caused by the surgical procedure. The bony fusion rate of fresh fractures in the presented series was 100%. With the HSS system, ca. 12% postoperative complications, such as slight reduction of head rotation or neck pain, were found. These results are virtually equal to the results of the double-screw technique. Since a relatively simple technical procedure is required for placement of the screw, the HSS system can be recommended in all cases of odontoid fractures suitable for direct anterior fixation.

Adolescent↗
PubMed1996

Intra-operative epidural morphine, fentanyl, and droperidol for control of pain after spinal surgery. A prospective, randomized, placebo-controlled, and double-blind trial.

The present study was conducted to investigate the analgesic effects of intra-operatively administered epidural morphine in patients undergoing surgery for lumbar disc disease. Three treatment groups were constituted: one with 5.0 mg morphine and 2.5 mg dehydrobenzperidol (DHB) in 10 ml physiological saline, one with 5.0 mg morphine and 0.1 mg fentanyl in the same amount of saline, and one placebo group with saline only. The test solution was injected epidurally via catheter after haemostasis and before closure of the wound. Sixty eight patients were randomly assigned to each of the three groups and subjected to a double-blind evaluation. In the morphine/fentanyl and morphine/droperidol groups, significantly better analgesia was found as compared to the placebo group. No significant difference was found between the morphine/fentanyl and morphine/droperidol groups considering side effects of therapy, as well as duration and quality of analgesia. The side effects in the treatment groups were only slight and not significantly different from the placebo group. It was shown that additional epidural fentanyl offers no significant improvement of postoperative analgesia. No significant reduction of adverse effects could be found in the morphine/droperidol group compared to the morphine/fentanyl group. In conclusion, the intra-operative epidural application of morphine is a safe, effective and simple method for achieving sufficient analgesia in the first 24 hours after lumbar spinal surgery for disc disease.

Analgesia, Epidural↗
PubMed1996

Back to the roots of modern neurosurgery: neurosurgical pioneers in Halle an der Saale.

At the end of the 19th and the beginning of the 20th centuries, German surgeons played a large role in the development of neurologic surgery. Many of them, however, have not been fully appreciated by the neurosurgical community until now. Pioneering personalities like F. Krause and F. von Bramann have contributed considerably to the early establishment of standard neurosurgical principles and operative techniques. Alexander Stieda was their successor and kept alive the neurosurgical tradition in Halle until the end of World War II. This middle-sized city in Central Germany, with an old university where Martin Luther once taught, was especially privileged to be one of the places where some of the best-qualified and restless surgeons have practiced neurologic surgery and done work in progress. This paper traces the biographies of the great old masters of German neurosurgery in search of the "Halle connection" to the progress of our field.

Brain Neoplasms↗
PubMed1996

Ultrasound-guided endoscopic fenestration of the third ventricular floor for non-communicating hydrocephalus.

Conventional valve shunting for treatment of hydrocephalus has a high rate of long-term complications. Endoscopic ventriculostomy by fenestration of the third ventricular floor, a minimally-invasive technique, avoids many of the drawbacks of extracranial shunting. Endoscopy was performed in 12 hydrocephalic patients with MRI-diagnosed aqueductal stenosis and neurological signs. Intraoperative ultrasound guidance allowed aiming the tip of the rigid endoscope to the foramen of Monro, and direct entering of the enlarged third ventricle. This technique is as exact as stereotaxy but is faster and easier. No complications were seen due to the surgical procedure. Nine patients were cured from their complaints, in 3 cases there was a subjective improvement of neurology. Long-term patency of the third ventriculostomy was confirmed by movement-sensitive MRI.

Adult↗
PubMed1996

Short test-period spinal cord stimulation for failed back surgery syndrome.

The aim of this study was to investigate the effects of spinal cord stimulation (SCS) on patients with chronic pain due to failed back surgery syndrome and to evaluate selection criteria for predicting SCS success. Thirty-two patients were enrolled in the present study. Prior to test implantation, all of them have been screened with various plan questionnaires and were selected for the SCS procedure according to stringent criteria. The single-electrode neurostimulators Itrel II and Xtrel were used with percutaneously inserted leads. The leads were placed under X-ray image intensifier control, and position was modified until optimum paresthetic coverage of pain areas was achieved. Twenty-nine of the 32 test stimulation patients reported on a pain reduction of at least 50% and up to 90% of preimplantation values. After a test period of 24 to 72 hours, internalization of the whole SCS system followed. In 3 cases the lead was explanted after 3 days of test stimulation because of insufficient analgesic effect. No major complications were seen in this highly preselected group. Follow-ups of 2 to 3.5 years after lead implantation proved stable analgesia and good outcome in 25 patients. Further 4 patients experienced a late failure of the system due to decreased analgesic effects of SCS. In conclusion, if the selection of SCS candidate patients is performed very carefully and according to well defined criteria, test stimulation periods can be kept relatively short, thus reducing therapeutic failures, risk of infection, and costs of therapy.

Adult↗
PubMed1996

Miliary brain metastases from malignant melanoma.

Malignant melanoma represents the third most common cause for central nervous system metastases after breast and lung cancer. Whereas breast, lung and kidney metastases are predominantly solitaire, malignant melanoma metastasizes often in a multiple way. Nevertheless, only about 5% of the patients with multiple melanoma metastases have more than five intracerebral metastatic lesions. The case of disseminated carcinomatous cell spreading throughout the brain is called "miliary metastases" or "carcinomatous encephalitis". This condition is very rare and correlated with a poor prognosis. We describe the case of a female patient with neuroradiologically diagnosed miliary brain metastases occurring five years after surgical excision of a forearm malignant melanoma. The clinical signs, diagnosis, and etiology of this rare phenomenon are discussed.

Brain↗
PubMed1995

Complete disappearance of giant intracranial germinoma after irradiation.

Intracranial germinomas are lesions with a varying, rather benign growth potential, and account for only 0.3 to 1.5% of all brain tumors. About 70% of the patients with these tumors are between 10 and 21 years of age at diagnosis. Germinomas are radiosensitive and respond well also to chemotherapy. The case of a 22-year-old male patient with a giant primary intracranial germinoma originating in the pineal region is presented. Clinical signs and symptoms are described together with neuroradiological, light-microscopic, and immunohistochemical findings. The tumor was irradiated with a total dose of 46 Gy and disappeared completely already after an effective tumor dose of 30 Gy. No recurrence was seen during a follow-up of three years. The patient's quality of life could be preserved and a complete cure was achieved.

Adult↗
PubMed1995

Thoracic and lumbar meningocele in neurofibromatosis type 1. Report of two cases and review of the literature.

We report two cases of ventrolateral thoracic and lumbar meningoceles associated with neurofibromatosis type 1, and present a review of the literature. Thoracic and lumbar meningoceles are rare lesions which are associated with neurofibromatosis in 60% to 85% of cases. Large meningoceles may cause pain, neurological signs, or respiratory complaints when located intrathoracically. Surgery is indicated in such cases, as well as when small meningoceles enlarge with time. The etiology of meningoceles in neurofibromatosis remains controversial. The authors postulate that ventrolateral lesions of the thoracic and lumbar spine are secondary to congenital mesodermal dysplasia and hypoplastic bone changes. MRI is the diagnostic method of choice, since it most adequately visualizes the pathological anatomy of the spinal cord, meninges, and adjacent structures in every sectional plane. CT scans are particularly useful in assessing the spinal bony changes.

Adult↗
PubMed1995

Dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease).

The case of a 30-year-old male patient is presented who was admitted with a 3-month history of elevated intracranial pressure and reduced-hearing on the right. CT revealed hydrocephalus due to displacement of the 4th ventricle by a large non-enhancing cerebellar mass with calcifications. MRI sequences showed a space-occupying lesion within the right cerebellar hemisphere with unusual septations. At operation, the poorly demarcated lesion was excised from the apparently normal surrounding cerebellar tissue and histologically proven to be a dysplastic gangliocytoma (Lhermitte-Duclos disease). Clinical and neuroradiological appearance of this rare entity, as well as hypotheses on its pathogenesis are discussed.

Adult↗
PubMed1995

Absence of p53 autoantibodies in sera from glioma patients.

Alteration of the tumor suppressor gene p53 is the most frequent genetic feature of human cancer and leads to over-expression and loss of function of the p53 protein in affected cells. Patients with many types of cancer, including breast, lung, and colon carcinoma, were shown to develop auto-immune response against the overexpressed protein and to produce autoantibodies directed to immunodominant epitopes common for both wild type and mutants. The presence of p53 autoantibodies (p53-aAb) seems to be, at least in patients with breast and bronchial tumors, related to an unfavorable prognosis. The present study aimed to investigate the presence of p53-aAb in patients with malignant glioma. Sera from 70 consecutive patients with gliomas graded WHO G III and IV were collected and assayed together with sera from 30 controls. A new photometric sandwich-ELISA was used for semiquantitative analysis of p53-aAb titers. p53 gene and its protein product were examined in formalin-fixed and fresh-frozen tumor tissues using immunohistochemistry, PCR-single-strand conformational polymorphism, and sequencing. Sixty percent of the glioma cases showed immunohistochemically positive cells, thus indicating intracellular accumulation of p53. Sequencing of the hot-spot exons 5-8 revealed mutations in 39% of the tumor cases. In contrast to results in other types of malignant tumors, where up to 40% of patients have high serum titers of p53-aAb, no such antibodies were found in patients with malignant cerebral glioma despite the presence of mutated or alterated p53 protein in the primary tumors. None of the non-cancer control patients had detectable titers of p53-aAb, although sera from five of six lung cancer patients had medium to high titers. The presented data suggest that glial tumors are unusual in the absence of serum antibodies to p53. It is hypothesized that impaired function of most immunocompetent cells invading brain tumors could be the cause for the absence of an autoimmune response.

Adult↗
PubMed1994

Abdominal CSF pseudocysts in patients with ventriculo-peritoneal shunts. Report of fourteen cases and review of the literature.

The abdominal intraperitoneal cerebrospinal fluid pseudocyst is an infrequent but important complication in patients with ventriculoperitoneal shunts. Since 1954, 115 cases of paediatric pseudocysts have been reported in the literature. One additional report deals with an adult patient. We report on 14 cases of sonographically diagnosed abdominal pseudocysts. Their aetiology, diagnosis, clinical signs and symptoms and surgical management are investigated. In our hydrocephalus series we have an incidence of pseudocyst formation of 4.5%. The most common presentation of the paediatric patients is with symptoms of elevated intracranial pressure and abdominal pain, whereas the adults have predominantly local abdominal signs. Diagnosis is readily made with ultrasonography. Predisposing factors for pseudocyst formation are multiple shunt revisions and infection. Microscopically, the pseudocysts consist of fibrous tissue without epithelial lining. The treatment involves surgical removal of the catheter with or without excision of the pseudocyst wall and placement of a new catheter intraperitoneally in a different quadrant or an intra-atrial shunt. Recurrences are rare, especially under appropriate medical treatment of infection. In our series, microbiologically proven infection was present in 30% of the cases.

Adolescent↗