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J Steenbeck

Publications and source records attributed to J Steenbeck.

5 recordsLinked to original sources
PubMed2003

[Pseudoaneurysm--a rare complication of internal jugular vein cannulation: two case reports in liver transplant patients].

Internal jugular vein catheterization is nowadays a routine procedure in clinical practice. Arterial puncture is the most common complication of internal jugular vein catheterization. Two cases of pseudoaneurysm formation as a complication of accidental arterial puncture in liver transplant patients with coagulopathy are presented. Punctures of the common carotid artery, thyrocervical trunk, respectively were the source for these lesions. Coagulopathy is seen as an essential factor in the formation of pseudoaneurysm. Especially in patients with coagulopathy the threshold for ultrasound guidance should be low. Under these circumstances using the external jugular vein seems to be more prudent as it eliminates the risk for arterial punctures. We illuminate the genesis, signs and symptoms, diagnosis, and therapy of pseudoaneurysm. Recommendations for risk reduction are given.

Aneurysm, False↗
PubMed2000

Source localization and possible causes of interictal epileptic activity in tumor-associated epilepsy.

Electrophysiological studies in gliomas have demonstrated action potentials in neoplastic cells. These "spiking tumor cells" are, however, an enigma. In attempt to find evidences for spikes within tumoral borders, 21 patients with different intracerebral tumors were preoperatively screened for the occurrence of epileptogenic discharges using multichannel MEG and EEG. A correlation between histopathology and the distance between dipole and tumor border could be found. Glioma patients showed epileptic activities closer to the border than those with mixed glioneuronal neoplasms and metastases. Four glioma patients demonstrated epileptic activity within the tumor boundary, however, not in the deep center of the tumor. Patch-clamping of cells from acute glioma slices did not yield a correlation between the presence of voltage-gated sodium channels in tumor cells and the MEG/EEG data. Our results demonstrate that the zone with the highest epileptogenic potential is different in gliomas and other brain tumors. However, our data do not strongly suggest that glioma cells are directly involved in the generation of tumor-associated epilepsy in vivo via their capability to generate action potentials.

Action Potentials↗
PubMed2000

Neuronavigation in surgery of intracranial and spinal tumors.

PURPOSE: To demonstrate the new possibilities and advantages of neuronavigation in the surgery of intracranial and spinal tumors, based on patient populations treated in our hospital. MATERIALS AND METHODS: An infrared navigation system with integrated microscope guidance was used for frameless intracranial neuronavigation. The biopsies of intracranial tumors were carried out using a frame-based stereotactic technique. Intracranial navigation was, in part, combined with the use of an intraoperative CT scanner and a three-dimensional ultrasound system for data acquisition, correction of brain shifts, and intraoperative quality control. The navigation was also supported by presurgical brain mapping with magnetic source imaging. Navigation in spinal surgery was exclusively performed using an infrared navigation system in combination with an intraoperative CT scanner. RESULTS: The stereotactic tumor biopsies (n = 57) were carried out with an accuracy of 91.4% as compared with the histological diagnosis. The work flow of stereotactic procedures could be increased by using the intraoperative CT scanner. Fifty-seven patients with intracranial tumors were treated with the aid of neuronavigation between July 1997 and December 1999. These patients showed an improvement from 80% to 86% on the Karnofsky index 8 weeks postoperatively. The majority of intracranial cases were primary brain tumors (n = 30) and metastases (n = 13) in functionally important areas of the brain. In four patients, a significant brain shift was observed during neuronavigation, and could be corrected by an image update using either the intraoperative CT scanner (n = 2) or the three-dimensional ultrasound system (n = 2). The presurgical brain mapping with magnetoencephalography was shown to be reliable in the sensory cortex (n = 25). Eleven patients with a thoracic or lumbar tumor were treated by open surgery or stabilization, using a combination of spinal neuronavigation and the intraoperative CT scanner. Two patients with spinal tumors underwent navigated biopsies. Neither of them showed a reduction in the clinical stage, but the Karnofsky index improved from 63% up to 72% 8 weeks postoperatively. CONCLUSION: Neuronavigation allows very precise intracranial and spinal surgery. The problem of brain shift during the navigation procedures has been solved by intraoperative image acquisition. The use of neuronavigation was shown to improve the postoperative quality of life of patients suffering from brain and spinal tumors.

Adult↗
PubMedDate not supplied

Technical developments in cardiac MRI: 2000 update.

In recent years, the technological developments in MRI have made it possible to perform routine cardiovascular imaging with MR. The availability of a vectorcardiogram, real time interactive scanning, SENSE and optimized protocols (balanced FFE) have made it possible to evaluate wall motion, perfusion and viability at rest and under stress. All vessels can be visualized, including the coronary arteries. In the near future, MRI will be capable of distinguishing between calcified and lipid plaque, and will even allow interventional applications.

Cardiovascular Diseases↗