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Biomedical subjects

W Wagner

Publications and source records attributed to W Wagner.

At least 127 records · Page 7Linked to original sources
PubMed1997

Infrared-based neuronavigation and cortical motor stimulation in the management of central-region tumors.

An infrared-based neuronavigation device (Surgical Microscope Navigator) integrating a pointer system with microscope guidance, is presented. We report our experience with this system in 17 patients undergoing surgery for space-occupying lesions of the central region. Cortical motor stimulation was additionally used in selected cases. The system was helpful in all operations by guiding craniotomy, corticotomy, or extent of tissue resection. Gross total tumor removal was possible in all patients but 1. Technical problems occurred in 1 case. Postoperative neurological worsening was found in 3 patients; this was reversible within a few weeks in 2 of them. In 9 cases, neuronavigation (combined with cortical stimulation, if necessary) probably prevented permanent neurological injury by exactly localizing tumors in the central area. It is concluded that neuronavigation (combined with motor cortex stimulation) may decrease neurological injury or neurosurgical invasiveness in lesions of the central region.

Astrocytoma↗
PubMed1997

[Backache--orthopedic diagnosis and special therapeutic possibilities].

Back pain is a wide-spread complaint in modern society and in part an adverse effect resulting from present-day lifestyles. To date, too little attention has been drawn to efficient prevention. The treatment of patients affected with back pain today calls for an in-depth pathophysiological knowledge about the mechanism occurring on the spine. Diagnostic methods and non-operative treatment have been complemented specifically by chirotherapeutic methods. A systematic classification of the vertebragenous pain syndromes and the related treatment strategies have proven to be successful. Irrespectively of that, the individuality of diagnosis and the complaint's progress in each patient should be taken into account at all events. Cost-intensive diagnostic imaging should only be undertaken with a clear indication. Today, the overwhelming majority of back pain patients undergo a non-operative treatment. In case the conservative applications prove inefficient, it is possible to successfully operate on patients a with disc prolaps, degenerative instabilities as well as osseous spinal foraminal stenoses. A precondition is a precise causal diagnosis and a clear indication for operative intervention.

Back Pain↗
PubMed1996

Ten years of fast neutron therapy in Münster.

The indication for neutron therapy in the treatment of malignant tumors is often uncertain. We therefore would like to present our experience of neutron therapy for different tumors in different localizations and discuss the indications for radiotherapy with neutrons. In Münster, 269 patients were treated with neutrons between 1985 and 1995, via a deuterium-tritium generator with an energy of 14 MeV. The tumors, treated mainly with neutrons, were 64 adenoid cystic carcinomas of the salivary glands, 42 soft tissue sarcomas, 37 rectal cancer recurrences and 20 recurrences in the head and neck region. Furthermore, patients with non adenoid cystic carcinomas of the salivary glands as well as ten other tumor sites also received this treatment, mainly with palliative intent. The 64 patients with adenoid cystic salivary gland tumors had either an unresectable primary tumor, an unresectable recurrence or residual tumor (R1, R2) after surgery. These patients showed complete remission in 78% and partial remission in 22%. The 2-year survival rate was 76%. Forty-two patients with soft tissue sarcomas after resection (R1, R2) and different gradings had an overall survival rate after 5 years of 53%. The 37 patients with rectal cancer recurrence experienced rapid pain relief in nearly 90% of cases. In agreement with the results in the literature, there seems to be an indication for neutron therapy in cases of unresectable primaries, unresectable recurrences or residual tumor after surgery in adenoid cystic carcinomas. Results regarding soft tissue sarcoma treatment with neutrons seem to show superiority in comparison with photon therapy. The treatment with neutrons of rectal recurrences has a very good palliative effect. The radiotherapy treatment with neutrons in all the other tumors did not demonstrate any proven superiority in comparison with photon radiation.

Actuarial Analysis↗
PubMed1996

Sealing ability of five different retrograde filling materials.

The sealing ability of Amalgam, Harvard-Cement, Diaket, gold-leaf, and Ketac-Endo as retrofilling materials was investigated. Paper cones were fixed with Harvard-Cement in the instrumented roots of 100 extracted human incisors. Apicectomy was performed and a 2-mm-deep retrograde cavity was prepared. Teeth were assigned to five groups (n = 20); each group received a different filling material. Surfaces of the roots were isolated with nail polish. Teeth, were stored in 1% methylene blue dye for 72 h. Roots were sectioned, and the depth of dye penetration was evaluated through a stereomicroscope. Retrofills with Ketac-Endo showed significantly less leakage compared with amalgam. There was no significant difference between the amalgam and Diaket groups. The sealing ability of Harvard-Cement and gold foil was lower than amalgam. It was concluded that retrograde fillings with Ketac-Endo or Diaket can be considered as alternatives for amalgam.

Bismuth↗
PubMed1996

[How traumatising is mechanical mucous membrane care after interventions on paranasal sinuses? A histological immunohistochemical study].

OBJECTIVE: Endonasal sinus surgery lead to more or less circumscribed mucosa defects exposing the underlying bone. Healing of these wounds is accompanied by crust formation, which may be subjected to mechanical debridement. It is not known whether this wound care impaires or facilitates wound healing. METHODS: Following sinus surgery, 72 crusts were removed from the operative site after having taken endoscopic photographs choosing different postoperative intervals. Mucosal biopsies were taken from beneath the crusts. All specimen were submitted to routine histological serial sections as well as immunohistochemical staining of epithelium. RESULTS: Local debridement of crusts avulsed parts of epithelium in 23% of cases during the first postoperative week. There was no histological evidence of avulsed epithelium with crusts removed the second week. This figure later increased to 16%. Possible trauma to regenerating mucosa cannot be predicted solely by the appearance of crusts. CONCLUSION: In principle, large crusts may disturb ventilation and drainage, causing secondary mucositis. Local care is mandatory in these cases. According to our examinations, mechanical debridement of wounds must respect the time-dependent irritability of the healing wound. There is little risk of impairing epithelization during the second week after surgery and the chance of sustaining the healing process is best.

Biopsy↗
PubMed1996

Scalp, earlobe and nasopharyngeal recordings of the median nerve somatosensory evoked P14 potential in coma and brain death. Detailed latency and amplitude analysis in 181 patients.

Median nerve somatosensory evoked potentials (SEPs) were recorded in a total of 181 patients in coma and brain death. Special attention was paid to derivation of P14 (the positive potential occurring approximately 14 ms after median nerve stimulation) with different electrode montages, using midfrontal scalp (Fz), linked earlobe (A1/2), median nasopharyngeal (Pgz) and non-cephalic reference (NC) electrodes. The P14 amplitude (and, to a lesser extent, latency) were invariably lower in brain death than in coma. The potential was preserved in coma in all patients, but lost in brain death in 9.8% in Fz-NC and Pgz-NC recordings, in 23.2% in Fz-A1/2, and in 100% in Fz-Pgz. Thus, Fz-Pgz was the derivation yielding the most reliable results with respect to the distinction between coma and brain death and is therefore recommended as a confirmatory test, when other diseases interrupting the lemniscal pathway (isolated brainstem death, high cervical transverse cord lesion and focal bilateral lemniscal lesion) are excluded. Theoretical considerations lead to the hypothesis of different (rostral and caudal) segments of the P14 generator dipole being recorded by the different electrode montages. It is assumed that Fz-Pgz picks up the most rostral part of P14 (rP14) that is invariably lost in brain death and preserved in coma.

Adolescent↗
PubMed1996

[Results of revision and new operation in arteriovenous shunt complications].

Over a 10 years period 260 arterio-venous fistulas have been performed and followed up. The Brescia-Ciminoshunt was the most frequent type (n = 174). This type of fistula has been performed in about 85.2% of all cases as primary operation method. In secondary formations the saphena-interposition was used most frequently (49.4% of all cases). A shunt revision should be performed in cases of immediate thrombosis although a shorter life time of revisioned shunts compared with new formations is known. The new formation of a shunt should be considered if terminal thrombotic changes have been detected as well as in cases of shunt infection or shunt insufficiency.

Arteriovenous Shunt, Surgical↗
PubMed1996

[The value of differential recording of subcortical somatosensory evoked potentials (SEP) in neurosurgery].

The role of subcortical median nerve somatosensory evoked potential (SEP) testing is exemplified in neurosurgical patients with syringomyelia, coma, brain death, or undergoing intraoperative monitoring. Of special importance is the isolated recording of two components with similar latencies but different generator sites: N13 (lower cervical spinal cord) and P14 (caudal brain stem). These two potentials overlap in conventional neck-scalp recordings using a frontal reference. Theoretical implications and practical aspects of a differential recording of subcortical SEP in neurosurgery are discussed.

Brain Death↗
PubMed1996

A fixed-dose combination of low molecular weight heparin with dihydroergotamine versus adjusted-dose unfractionated heparin in the prevention of deep-vein thrombosis after total hip replacement.

The low dose heparin regimen (LDH) is not appropriate for prevention of intra- and postoperative thromboembolic complications in high risk patients, especially those undergoing elective hip replacement. Despite LDH prophylaxis, the incidence of deep-vein thrombosis (DVT) remains in a range of 20 to 35%. Adjusted-dose unfractionated heparin prophylaxis is thought to be one of the most effective regimens for thrombosis prophylaxis in this indication, but it requires two or three daily injections as well as precise monitoring of the activated partial thromboplastin time (aPTT). As an attractive alternative, we investigated the efficacy and safety of the low molecular weight heparin (LMWH) certoparin combined with dihydroergotamine (DHE) given once daily. In a randomised, open clinical trial, a total number of 305 patients undergoing total elective hip replacement were enrolled and divided into two groups, either receiving a fixed-dose combination of LMWH (3,000 IU) and DHE (0.5 mg) subcutaneously once daily, or adjusted-dose unfractionated heparin (UFH) subcutaneously every 8 h. The UFH dosage was adjusted daily to keep an aPTT of about 50 s. The aPTT was determined 3 h after the morning injection. During the study, the starting dose (15,000 IU/day) was increased to a plateau value of 28,800 +/- 7,150 IU/day (mean +/- SD) to maintain the aPTT in the prescribed range. The plateau value was achieved after 8 postoperative days. For analysis of efficacy 289 patients were evaluable. The occurrence of deep vein thrombosis was determined by bilateral ascending venography, which was performed on the same day in patients with clinical signs suggesting DVT; and in all remaining patients at the end of the prophylaxis period. Deep vein thrombosis was diagnosed in 17 of 142 patients (12.0%) treated with LMWH/DHE and in 13 of 147 patients (8.8%) treated with adjusted-dose UFH. Combined distalproximal thrombosis was more frequently in patients receiving UFH (n = 5; 3.4%) compared to the LMWH/DHE group (n = 2; 1.4%). These differences are statistically not significant. In the UFH group one case of non-fatal pulmonary embolism occurred. Both prophylaxis regimens were well tolerated; wound bleeding was observed in 8 (5.3%) patients in the LMWH group and in 6 (4.0%) patients in the UFH group. Intraoperative blood-loss volume (mean +/- SD) was 751 +/- 339 mL (LMWH/DHE) and 736 +/- 380 mL (UFH), whereas postoperative drain-loss volume (mean +/- SD) was found to be 523 +/- 333 mL (LMWH/DHE) and 581 +/- 404 mL (UFH). Whole blood transfusion volumes (mean +/- SD) were 570 +/- 202 mL (LMWH/DHE) and 748 +/- 455 mL (UFH). Additionally, red cell replacement volumes (mean +/- SD) were 804 +/- 435 mL (LMWH/DHE) and 720 +/- 328 mL (UHF). Revision of wound or additional drainage were necessary in 3 LMWH/DHE and 7 UFH patients. One patient needed reoperation due to bleeding, 3 (2.0%) had petechia and 1 exhibited an allergic exanthema, all of them in the UFH group. A slight erythema at the injection site was observed in 6 (3.9%) patients receiving LMWH/DHE. During the course of prophylaxis, injection hematomas were documented in 57.9% (LMWH/DHE) and in 61.4% (UFH) of the patients. All differences were statistically not significant. Single daily subcutaneous injections of LMWH/DHE appeared to be safe and efficacious compared to adjusted-dose UFH for prophylaxis of DVT in high-risk patients.

Aged↗
PubMed1996

[Radiotherapy of epidural metastases with spinal cord compression].

BACKGROUND: We have evaluated the records of patients who developed epidural metastases with spinal cord compression and underwent X-ray therapy in combination with dexamethasone. The results, prognostic factors and live-tables will be demonstrated. PATIENTS AND METHOD: Between 1984 and 1995 48 patients were treated at the Department of Radiooncology at the University of Münster because of epidural metastases. All but 3 cases were histologically proved. Three patients were irradiated without definitive histology because of clinical symptoms and CT or MR-imaging. Only patients with solid tumors were considered-patients with systemic diseases like leukemia or lymphoma were not analysed. In all of our cases irradiation was combined with systemic steroid application. Radiotherapy was performed with cobalt-60 or with an accelerator with total doses between 25 Gy and 40 Gy. RESULTS: The combination of irradiation and steroids had resulted in pain relief in about 80% of all patients. The ambulatory status after paraparesis was restituted in 35%. Best prognosis had been seen in patients with the following criterions: primary tumor should be breast cancer, no evidence of other tumor manifestation, no signs of paraparesis or paraplegia before the beginning of irradiation or regaining the ambulatory status after therapy. Under these conditions we have calculated a median survival rate of 709 days for these patients with good prognosis. Patients with bronchogenic carcinoma had a very poor prognosis with a median survival rate of only 90 days. CONCLUSIONS: Epidural metastases in cancer led often to a very fatal outcome. Irradiation is useful for pain relief and also for local tumor control. In some cases in patients with good prognostic factors long-time survival could be demonstrated. The results of irradiation are comparable with those after surgery.

Adult↗
PubMed1995

Properties of human affect induced by static color slides (IAPS): dimensional, categorical and electromyographic analysis.

Human affect elicited by static color slides was evaluated quantitatively using dimensional (N = 60 subjects) and differential or categorical (N = 57) self report, and facial electromyography (N = 20). Mean dimensional self reports of affective responses were highly replicable across cohorts. Mean categorical response profiles over seven affective categories were monomodal for some slides, but multimodal for most, and nearly identical within the same cohort for slides of similar content. Mean categorical response profiles for individual slides were also similar across different cohorts and for different experimental conditions. Valence calculated from weighted categorical self report scores was highly correlated with the self reported valence (r = +0.98), demonstrating a simple, linear relationship between dimensional and categorical (differential) measures of affect. Categorical response strength was synergically patterned, i.e. invariably correlated positively for affect of the same dimensional valence and generally correlated negatively for affect of opposite valence. Facial electromyograms associated with affective responses to slides were correlated with valence, but smaller in magnitude than those associated with the weakest possible voluntary facial movements involving the same muscles. This study, therefore, demonstrates that self reported affective responses to color IAPS slides are replicable within and between cohorts, complex but synergically patterned, and relatively weak.

Affect↗
PubMed1995

External proton beam analysis of layered objects.

Ion-beam analysis for determining the elemental composition and to obtain depth information has been carried out with MeV protons in air by means of simultaneous external PIXE and RBS. Stainless steel products of extended size and a historic painting are analyzed non-destructively. These objects include systems of layers with areal densities up to some ten mg/cm(2). Depth information is obtained by PIXE using energy variation of the primary proton beam and in addition directly from RBS for the outermost near-surface region. Main and secondary elements as well as impurities can be determined together with areal densities. Particularly, the knowledge on the depth distribution of the pigments in paintings provides information on paint techniques.

Journal Article↗
PubMed1995

Retained pieces of wood in the retromaxillary space: a case report.

Detection and operative removal of wood as a foreign body in the cranio-maxillary area has received frequent attention in the literature. However, as a rule, most of the cases described are related to the orbit or the orbito-neurocranial space. Almost no literature exists on the detection and treatment of wooden foreign bodies in the retromaxillary space. The authors present an unusual case of long-term retained wood in this area in a child. The case inspires discussion of the general problem of detecting retained retromaxillary wood, even using modern diagnostic tools in this area and the question of the operative therapy, especially the most favourable surgical access.

Child↗
PubMed1995

Intraoperative monitoring of median nerve somatosensory evoked potentials in cervical syringomyelia: analysis of 28 cases.

Intraoperative median nerve somatosensory evoked potentials (SEP) were monitored in 28 patients undergoing surgery for cervical or cervicothoracic syringomyelia. Analysis was focused on SEP components N13 (spinal cord), P14 (brain stem), and N20 (cortex). N13 was lacking in nearly 87% of the patients (due to a combined effect of syringomyelia and general anesthesia) and never recovered. P14 showed a significant (> 10%) intraoperative latency increase in two patients; this was irreversible in one patient who had a postoperative worsening of sensory function. N20 showed no relevant alterations. Pure motor deficits after surgery were not predicted by SEP monitoring. In conclusion, intraoperative P14 recording helped to identify harm to the dorsal columns and probably prevented the cord from irreversible damage in one case, whereas N13 recording did not contribute to the monitoring of spinal cord function during surgery for syringomyelia.

Adult↗