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Biomedical subjects

F Böck

Publications and source records attributed to F Böck.

At least 19 recordsLinked to original sources
PubMed1995

Percutaneous endoscopic lumbar discectomy: minimally invasive, but perhaps only minimally useful?

BACKGROUND A few recent studies dampen the euphoric reports of the value of percutaneous endoscopic lumbar discectomy (PELD) in the treatment of discogenic disease. We felt that a large-scale comparison between PELD and the still minimally invasive open lumbar disk surgery (OLDS) was called for. METHODS This report is based on the surgical experience of one year (1991) and is confined to the intervertebral disk level L4-5. Three hundred thirteen patients treated by open disk surgery were compared with 13 who were selected for percutaneous discectomy. RESULTS Using careful selection criteria, only 13 (4%) of a possible 326 were considered potentially suitable for PELD. Of these, only eight were wholly suitable and were operated on percutaneously. Within the first postoperative month, 62.5% (5 patients) of the PELD group required open surgery for definitive treatment, whereas only 14 (4%) of the 313 OLDS patients had to undergo additional surgery. CONCLUSIONS Although it may of benefit to a very few, we feel that the PELD method cannot be considered a substitute for, or even an alternative to, traditional surgery in most cases.

Adult↗
PubMed1995

Is blood pressure really a trigger for the circadian rhythm of subarachnoid hemorrhage?

BACKGROUND AND PURPOSE: Circadian blood pressure changes are not infrequently cited as a trigger for the onset of subarachnoid hemorrhage (SAH). Our purpose was to determine the reliability of this chronorisk and study the variability and consequences of it as it occurs in hypertensive and normotensive individuals. METHODS: Of 273 consecutive patients with proven SAH of aneurysmal origin seen between January 1990 and December 1993, we studied 120 (44%) for whom the exact time of hemorrhage could be reliably determined. Beyond the recognition of a circadian rhythm for this collective, the patients were then sorted by blood pressure, yielding one group each of 80 normotensive (group N, 66.7%) and hypertensive (group H, 33.3%) individuals. The differential chronorisk of these two groups was studied. RESULTS: A circadian rhythm with a definitive characteristic acrophase was observed for the entire group, occurring between 9 AM and 10 AM (chi 2 test, P < .0005) with a possible secondary peak in the afternoon hours. The separation into two blood pressure groups somewhat surprisingly revealed a different curve for each group (chi 2 test, P = .01). Statistical analysis of each group's separate chronorisk revealed that this acrophase only holds true for hypertensive individuals, whereas normotensive patients not only lack a morning peak, but an apparent elevation in the afternoon is statistically irrelevant, leading to the impression that SAH in normotensive persons seems to be subject to no circadian rhythm at all. CONCLUSIONS: The incidence of SAH conforms to circadian blood pressure variation in hypertensive patients, similar to the diurnal rhythms observed with strokes and myocardial infarctions. This leads to the hypothesis that blood pressure elevation is a trigger for the onset of bleeding in this group. In clear contrast, normotensive individuals with cerebrovascular aneurysms seem to have a random 24-hour distribution of SAH onset times, thus leaving the nature of a possible trigger mechanism unresolved.

Adolescent↗
PubMed1993

[Immunoscintigraphy for detection of inflammatory perioperative foci].

The aim of our study was to evaluate the clinical usefulness of a monoclonal antibody (MAB; BW 250/183; Behringwerke, Germany) in patients with suspected perioperative septic foci. The MAB is directed against the nonspecific crossreacting antigen (NCA 95) which has been found on the surface of human neutrophil granulocytes and which represents a murine immunoglobulin isotype of IgG1. Immunoscintigraphy was performed by labelling the MAB with 740 MBq (20mCi) Tc-99m. Data acquisition followed 4 and 18 to 24 hours after administration by a digital Anger camera (APEX 409A, Elscint). 53 patients were investigated (31 female, 22 male; average age 39 years), 4 patients were twice, 1 patient was 3 times evaluated, which results in a total of 59 studies. 45 patients experienced operation within 12 hours after our investigation, which resulted in 36 true positive, 5 true negative, 3 false negative, and 1 false positive findings. This means a sensitivity of 92%, and specificity of 83%. Immunoscintigraphy with granulocyte antibodies can be performed at any time, the preparation of the radiopharmaceutical is simple, the image quality is high; the obtained information concerning localization and size of perioperative septic infections permits the determination of the optimal point of time for surgical intervention. The accumulation of activity was visible as early as 4 hours post application. SPECT would enhance the diagnostic accuracy, but this technique cannot be applied in all such patients.

Abscess↗
PubMed1992

[Intracerebral hemorrhage from the neurosurgical viewpoint].

After the introduction of computed tomography intracerebral haemorrhage (ICH) was diagnosed more frequently. We discuss the role of surgical strategies for treatment of ICH of different aetiology. The main factors for surgical intervention for ICH (except vascular malformations) are: degree of midline shift, deformation of neurological deficit or consciousness-level and ventricular enlargement. In small hematomas surgical evacuation is of no benefit for final outcome.

Cerebral Hemorrhage↗
PubMed1990

[Immunoscintigraphy for the detection of inflammation foci in bone and joint diseases].

We evaluated the monoclonal antibody MAb, BW 250/183, which is easy to label with Tc-99m, with respect to its clinical application for the detection of inflammatory processes in bone and joint diseases. This monoclonal antibody is a murine immunoglobulin (IgG1 isotype), directed against NCA 95 (nonspecific cross-reacting antigen), which is also present on the surface of neutrophil granulocytes. We investigated patients with acute (n = 9) and chronic (n = 3) osteomyelitis, with coxitis (n = 3) and coxarthrosis (n = 2), with septic hip prosthesis (n = 8) and loosening hip prosthesis (n = 14), with low back pain (n = 4), with spondylitis (n = 5) and with postoperative spondylodiscitis (n = 9). With reference to the total number of patients examined in this study we found 29 true positive results, 22 true negative results, 4 false negative results and 2 false positive results. This gives a sensitivity of 88% and a specificity of 92%. The lesions were already visualized within 4 to 6 hours, but 24 hour pictures are desirable. SPECT pictures are mandatory in patients with diseases of the hip or of the spine because sensitivity is considerably improved thereby.

Adolescent↗
PubMed1990

Invasion of the cavernous sinus by medial sphenoid meningioma--"radical" surgery and recurrence.

We have reviewed the cases of 57 patients with medial sphenoid meningioma who were operated on in our department during the period 1976 to 1988. The patients were grouped according to location, and their pertinent clinical features are presented. Given the frequency of invasion of the cavernous sinus by such tumours, the following question must be considered in each individual case: the potential benefit of the most radical surgery possible, to minimize the recurrence rate, must be weighed against the cost to the patient in diminished quality of life of iatrogenic neurological impairment. We currently advocate the following strategy: radical removal of tumour tissue lying within the cavernous sinus is unwarranted for the first operation if it would entail iatrogenic neurological damage. Only if subsequent follow-up reveals either fast growth of this tissue, or neurological signs and symptoms attributable to it, do we then attempt uncompromising radicality at a second operation.

Brain Neoplasms↗
PubMed1988

Meningeal melanocytoma. Report of a case and review of the literature.

A primary localized, partly encapsulated melanotic tumour broadly attached to the occipital dura and tentorium was removed from a 27 year-old woman. It recurred almost four years later in the posterior fossa and was resected again. Although grossly resembling a meningioma, the tumour lacked the histological, immunocytochemical and ultrastructural features of meningiomas and was characterized by the presence of numerous melanosomes and premelanosomes in the cytoplasm of tumour cells and macrophages and was, therefore, classified as "meningeal melanocytoma". The clinical and pathological features of this and 15 other cases in the literature are reviewed. The neoplasm, mainly occurring in the posterior cranial fossa and spinal canal, may cause neurological deficits through expanding, but non-invasive growth. Its biological behaviour is variable, and recurrence may occur after incomplete resection, but transition into malignant melanoma has not been observed. Total resection of this rare pigmented tumour arising from the pial melanocytes is recommended.

Adult↗
PubMed1988

[Recombinant tissue-type plasminogen activator: pharmacokinetics and effect on the hemostasis system of the human].

The in vitro interaction of rt-PA with the coagulation and fibrinolytic system was investigated. After addition of rt-PA to citrated plasma prolonged clotting times for prothrombin time, partial thromboplastin time and thrombin time, decreased activities of individual clotting factors and decreases of alpha 2-antiplasmin, plasminogen and fibrinogen were measured. The alterations were dependent on incubation times and rt-PA concentrations and were mainly observed at rt-PA concentrations exceeding therapeutic levels. These in vitro phenomena could be prevented to different degrees using various inhibitors. Because of interferences with some fibrinolytic and coagulation assays aprotinin was only of limited utility as an inhibitor. PPACK lengthened clotting time assays based on generation of endogenous thrombin, but did not affect fibrinolytic assays. The most versatile inhibitor was a specific anti-rt-PA antibody which enabled correct measurements of all fibrinolytic and most coagulation assays. It is concluded that high rt-PA levels in samples taken from patients during fibrinolytic therapy induce in vitro artefacts which can be prevented by the use of suitable inhibitors. In 8 healthy male volunteers aged 32 +/- 7 years pharmacokinetic investigations were done. After infusion of 0.25 mg rt-PA/kg bw mean maximal plasma levels were 970 +/- 130 ng/ml. The elimination of rt-PA from plasma was fitted to a two compartment model and was characterized by two half lives of t1/2 alpha = 3.3 and t1/2 beta = 26 minutes.

Adult↗
PubMed1984

Cerebral granulomatous angiitis with atypical features.

A case of cerebral granulomatous angiitis of the left temporal lobe mimicking a brain tumour is presented. Following surgical removal of a glioma-imitating mass, histological examination disclosed a granulomatous vasculitis. Treatment consisted of dexamethasone given in tapering doses for 5 days after surgery. Clinical and morphological differences from other reported cases of granulomatous angiitis of the nervous system are described.

Adult↗
PubMed1981

Cerebral space-occupying cysts following radiation and chemotherapy of malignant gliomas.

Eight cases of cerebral cyst formation among 50 patients (= 16%) with malignant supratentorial gliomas treated by surgery, megavoltage radiation, and multiple-agent chemotherapy are reported. Five of them developed signs of intracranial hypertension or progressive neurological deficit, while in three patients cerebral cysts were detected by CT without clinical deterioration. At operation or autopsy, or both, the large fluid-filled, smooth-walled cysts were lined by glio-mesenchymal scar tissue with no or little tumour recurrence in five, while three patients showed large recurrent tumour masses associated with necrosis and cyst formation. Clinical signs or CT evidence, or both, of cerebral cysts developed 4 to 12 months (average 10 months) after the first craniotomy, and 3 to 9 months after termination of radiotherapy, usually after the second to fourth course of polychemotherapy. The cystic cavities which are attributed to increased necrosis and other effects of radiation and cytostatic treatment, may mimic tumour progression or recurrence, and cerebral abscess, but are usually recognized by CT. Surgical treatment produced transient clinical improvement in 5 patients, but usually did not prevent the fatal outcome of the disease, which in these paticrosis and other effects of radiation and cytostatic treatment, may mimic tumour progression or recurrence, and cerebral abscess, but are usually recognized by CT. Surgical treatment produced transient clinical improvement in 5 patients, but usually did not prevent the fatal outcome of the disease, which in these paticrosis and other effects of radiation and cytostatic treatment, may mimic tumour progression or recurrence, and cerebral abscess, but are usually recognized by CT. Surgical treatment produced transient clinical improvement in 5 patients, but usually did not prevent the fatal outcome of the disease, which in these patients occurred 3 weeks to 6 months after surgical treatment of cyst formation, their life span ranging from 9 to 22 months. The pathogenesis and clinical problems related to cerebral cysts arising following multimodality treatment of malignant brain tumours are discussed.

Adult↗