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Biomedical subjects

W Lanksch

Publications and source records attributed to W Lanksch.

At least 19 recordsLinked to original sources
PubMed2000

Transvenous occlusion of dural cavernous sinus fistulas through the thrombosed inferior petrosal sinus: report of four cases and review of the literature.

BACKGROUND: The aim of this study is to describe the technique and results of the endovascular approach through the thrombosed inferior petrosal sinus (IPS) for occlusion of dural cavernous sinus fistulas (DCSFs). METHODS: In four patients presenting with clinically symptomatic DCSFs, the angiogram did not show opacification of the IPS, indicating that it neither drained the arteriovenous fistula nor the cerebral venous outflow. A large volume biplane phlebogram of the jugular bulb was obtained to identify a thrombosed remnant of the IPS. We were able to navigate small hydrophilic catheters and microguide wires through the thrombosed IPS into the ipsi- or contralateral CS. After reaching the fistula site the CS was packed with detachable platinum coils. RESULTS: We were able to reach the fistula site and to achieve a dense packing of coils within the arteriovenous shunting zone in all of the patients. The final angiogram showed subtotal or complete occlusion of the arteriovenous fistula. All four patients recovered completely and showed disappearance of the fistula on follow-up arteriograms. One patient developed a transient sixth nerve palsy. No complications related to the approach were observed. CONCLUSIONS: For endovascular treatment, transvenous occlusion of DCSFs via the IPS is a feasible approach, even when this sinus is partially or completely thrombosed. Gentle handling of recently available, improved hydrophilic microguide wires and microcatheters allows effective and safe catheter navigation into the CS. A phlebogram of the jugular bulb is very useful for identification of a thrombosed IPS.

Aged↗
PubMed1998

Imaging in epidural lipomatosis.

This paper reviews the literature concerning symptomatic epidural lipomatosis. The different diagnostic procedures (conventional myelography, computed tomography, and magnetic resonance imaging) and therapeutic approaches (including medical treatment, surgery, and dietary influence) are discussed.

Journal Article↗
PubMed1998

Dual-switch valve: clinical performance of a new hydrocephalus valve.

The Dual-Switch valve (DSV) is the first construction on the market which changes between two different valve-chambers in parallel depending on the posture of the patient. In the lying position the valve acts like a conventional differential pressure valve, in the vertical position the high-pressure chamber only opens, when the pressure exceeds the hydrostatic pressure difference between the formanen of Monro and the peritoneal cavity. The new device has been implanted in 32 adult patients with hydrocephalus of different etiology. The clinical results are excellent to good accompanied by a remarkable slight reduction of the ventricular size. Apart from one case with a nonsymptomatic transient hygroma, we saw no valve related complications like overdrainage, underdrainage or dysfunction. Contrary to conventional differential-pressure valves, adjustable devices and other hydrostatic constructions like the Anti-Siphon-device (ASD) or Deltavalve, the DSV reliably controls the IVP independently of the posture of the patient, the CSF viscosity or the subcutaneous pressure. In contrast to the Orbis-Sigma-valve (OSV) or the Diamond-valve, the DSV does not control the flow but the physiological IVP avoiding the increased risk of mechanical failure. The results of this study give strong evidence that the shunt-therapy of adult hydrocephalic patients can be significantly improved by the DSV.

Adult↗
PubMed1998

Custom-made cast titanium implants produced with CAD/CAM for the reconstruction of cranium defects.

Titanium implants for the reconstruction of bony skull defects, using data from three-dimensional spiral computer tomography, have been described by other authors. Instead of milling the implants from a titanium block, an advanced method of rapid prototyping for a fine casting process is presented. Casting vs milling offers several advantages. It is possible to form very thinly tapered structures and to obtain more complex geometrical structures with smaller diameters. Many geometrical forms, which cannot be milled for technical reasons, can be produced using this technique.

Adult↗
PubMed1997

The Doppler guide wire: clinical applications in neuroendovascular treatment.

The application of Doppler-tipped guide wires to measure blood flow velocity in coronary and peripheral arteries has been described previously as a valuable means of functional assessment in interventional cardiological procedures. In animal studies intravascular Doppler has been used in the cerebrovascular system, and this appears to be an important field of application for this new technique. We used intravascular haemodynamic monitoring by the Doppler guide wire during neuroendovascular procedures in patients with different cerebrovascular diseases and evaluated the clinical feasibility of the method. We found it a safe technique which complements morphological angiographic information with valuable functional data. Further studies may be expected to demonstrate the relation of flow parameters to clinical outcome.

Adult↗
PubMed1996

Intraaneurysmal flow: evaluation with Doppler guidewires.

Flow dynamics in cerebral aneurysms were studied with the use of Doppler guidewires in two patients. In both cases it was possible to reach the aneurysmal sac and to assess intraaneurysmal flow. Torquability and flexibility of the new Doppler guidewires permitted continuous assessment of flow velocity and flow pattern at the dome as well as in the neck area. Flow velocities were higher at the neck than within the aneurysmal sac (88 cm/s > 28 cm/s). Because of the limited area of interrogation (sample volume, 5 mm) it was not possible to investigate the complete intraaneurysmal space.

Adult↗
PubMed1995

[Diagnosis of cerebral metastasis with standard dose gadobutrol vs. a high dose protocol. Intraindividual evaluation of a phase II high dose study].

PURPOSE: To assess the effectiveness and safety of normal and high doses of Gadobutrol versus a standard dose of Gadolinium DTPA in the MR evaluation of patients with brain metastases. MATERIAL AND METHODS: In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spin-echo images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. RESULTS: Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. CONCLUSION: The first in vivo results prove the excellent contrast capacity of the nonionic contrast agent Gadobutrol for the diagnosis of intracerebral metastases.

Adult↗
PubMed1994

The treatment of spondylotic cervical myelopathy by ventral discectomy. Long term results on 121 patients.

The pathophysiology of spondylotic cervical myelopathy is still a matter of discussion. This paper presents a series of 126 patients operated on using a ventral approach. In 47% of the patients only a spondylotic narrowing of the spinal canal was present and in 35% an additional disc herniation was found. In 13% of the cases however a soft disc without spondylotic spures was found and in 5% a dislocation of vertebral bodies. We found a marked male preponderance of 77%, mean age was 51.6 years, ranging from 25-50 years. Most patients were operated on at the levels of C4/5 and C5/6. Observation time covered a period of 3-10 years. The outcome was rated relatively to the preoperative degree of disablement using a questionnaire for the patients and their family doctors. We found a marked difference in the answers, especially in rating deterioration, which was stated by patients in 34%, by physicians only in 12%. Another finding was the time-related outcome. We found best results with 75% improvement and 5% deterioration between 3-6 months postoperatively, with increasing time the results decreased to 33% improvement, 33% identical statys and in 33% a deterioration related to the preoperative status must be noted.

Adult↗
PubMed1993

Long-term observations of intracranial pressure after severe head injury. The phenomenon of secondary rise of intracranial pressure.

The long-term course of intracranial pressure (ICP) was studied in 53 patients from a group of 90 patients with severe head injury treated over a 3-year period. In 49 of these, ICP was significantly elevated during the observation period. The maximum in ICP was usually observed 24 to 96 hours posttrauma. A subgroup of patients developed a second rise of ICP. Such a course was observed in 15 (31%) of the 49 patients with intracranial hypertension. In these cases, ICP increased initially to 20 to 30 mm Hg but could be controlled. Thereafter, ICP was decreased again for at least 12 hours. The secondary ICP rise occurred 3 to 10 days after trauma. In six patients, intracranial hypertension became uncontrollable and eventually caused brain death. The outcome of patients with a secondary rise of ICP was worse when compared with that of patients without this complication. A cause of the secondary ICP rise could only be identified in some cases. Delayed traumatic intracerebral hemorrhage, traumatic vasospasm, hypoxia, and hyponatremia were diagnosed in seven cases. In seven other patients, the secondary ICP rise coincided with a pronounced leukocytosis, which was not associated with apparent infections. Because the occurrence and degree of a secondary rise of ICP after severe head injury are important factors affecting outcome, monitoring of ICP after severe head injury should be prolonged.

Adolescent↗
PubMed1992

[The regional blood flow in intracranial tumors: a comparison of HMPAO-SPECT with a newer magnetic resonance tomographic procedure].

We compared the value of gadolinium-enhanced first-pass MRI perfusion studies and HMPAO-SPECT for the assessment of regional cerebral blood flow in a prospective study of 23 intracranial tumour patients. In five tumours with homogeneous hypoperfusion and eight tumours with homogeneous hyperperfusion, tumour blood flow patterns in MRI and HMPAO-SPECT were similar. By contrast, in ten patients with inhomogeneous tumour blood flow pattern only MRI was able to differentiate between tumour areas with no or low flow, tumour tissue with high flow, and perifocal oedema with reduced flow. In HMPAO-SPECT, these inhomogeneous tumours were represented as areas of homogeneously reduced tracer retention corresponding to different tumour constituents and perifocal oedema. In conclusion, the high spatial resolution of MRI enables a detailed analysis of tumour blood flow.

Brain↗
PubMed1990

"Meningeal sign": a characteristic finding of meningiomas on contrast-enhanced MR images.

In meningiomas, a flat, contrast-enhancing, probably dural structure adjacent to the tumor can occasionally be observed on Gadolinium-DTPA enhanced MR images. This so called "meningeal sign" was evaluated with respect to the differential diagnosis of meningiomas in MR imaging. The study included 29 patients with intracranial meningiomas and 24 patients with non-meningeal brain tumors. In all meningiomas, MR studies included T2-weighted as well as unenhanced and Gadolinium-DTPA-enhanced T1-weighted images. In all non-meningeal tumors, Gd-DTPA-enhanced MR images were available. All images were evaluated with respect to the presence of the "meningeal sign". In meningiomas, a "meningeal sign" was seen in 15/29 cases on Gadolinium-DTPA-enhanced images. No abnormalities corresponding to the areas of contrast enhancement were found on unenhanced T2- and T1-weighted MR images. In non-meningeal tumors only 2/24 cases showed a "meningeal sign". In conclusion, with a sensitivity of 52% and a specificity of 92%, the demonstration of the "meningeal sign" improved the differential diagnosis of intracranial meningiomas in contrast-enhanced MR imaging.

Adult↗
PubMed1990

Multiple slice FLASH imaging: an improved pulse sequence for contrast enhanced MR brain studies.

A multisclice gradient echo sequence (FLASH) was compared with a conventional spin-echo (SE) technique with regard to its value for contrast enhanced brain studies. In 50 patients with contrast enhancing intracranial lesions, MR studies (0.5 Tesla MR tomograph) were performed with SE images (SE 400/30; four images/3.4 min) and FLASH scans (FLASH 315/14, 90 degrees; 15 images/1.4 min) before and after Gd-DTPA. Based on visual and quantitative assessment diagnostic results of postcontrast SE- and FLASH images were equivalent with respect to contrast enhancement, lesion/brain-contrast, lesion/edema-contrast, and lesion delineation. Although image quality generally was excellent on postcontrast FLASH images, susceptibility artifacts were more severe on FLASH scans than on SE images. However, with the exception of postoperative patients with artifacts due to metal remains, diagnostic information was not decreased by artifacts on postcontrast FLASH images. In conclusion, because of the clearly higher efficiency of the multisclice FLASH technique, this pulse sequence offers the opportunity to speed up contrast enhanced brain imaging.

Adult↗
PubMed1987

[Radiotherapy of medulloblastoma].

Between 1970 and 1985, 29 patients were postoperatively irradiated for medulloblastoma. Eight out of them received only a local irradiation and 21 a complete CNS irradiation. The posterior fossa was saturated up to a dose of 45 to 49 Gy in nine patients and 50 to 55 Gy in twelve patients. The patients treated by complete CNS irradiation show a three-year survival rate of 47% and a five-year survival rate of 40%. A nonsignificant increase of the three-year survival rate is found in patients whose posterior fossa was exposed to a higher radiation dose. Eleven recurrences were observed, and the posterior fossa was involved in seven out of these cases. Four recurrences confined to the spine were found after a dose of 20 to 30 Gy. Remote metastases, preferentially with a skeletal site, were formed in three out of 29 cases.

Adolescent↗
PubMed1983

Computed tomography of the "armored brain".

A calcified chronic subdural hematoma may cover the surface of the cerebral hemispheres to such an extent that one can talk of an "armored brain". Pathogenesis, clinical course and treatment are discussed based on the computed tomograms of five cases.

Adolescent↗
PubMed1982

Do we need ventriculography in the era of computed tomography?

The question is posed whether in the investigation of intracranial tumors, particularly in the posterior cranial fossa, CT and/or ventriculography should be practiced. We investigated 134 patients (93 were children up to the age of 14 years), all of whom had had both computed tomography and ventriculography. The results clearly demonstrate the superiority of CT compared with ventriculography. Ventriculography is a surgical intervention with risk for the patient; side effects may occur and serious complications can sometimes arise. Modern CT is producing pictures of high quality which are entirely sufficient for neurosurgical intervention. Very rarely does additional angiography have to be performed. The diagnosis of intracranial tumor can be fully established by CT and ventriculography is no longer necessary.

Adolescent↗
PubMed1982

[Computed tomography and/or ventriculography? (author's transl)].

It is discussed if in intracranial tumors, especially in tumors of the posterior cranial fossa, a CT and/or a ventriculography should be practiced. We have made investigations of 134 patients, 93 of whom were children up to 14 years of age. Each case was undertaken computed tomography as well as ventriculography. The results are clearly demonstrating the superiority of computed tomography compared with ventriculography. Ventriculography is a surgical intervention stressing the patients, side-effects may occur, and sometimes serious complications are caused. Modern computed tomography is producing pictures of high quality, which are highly sufficient for neurosurgical intervention. Very rarely additional angiography has to be performed. The diagnosis of intracranial tumors can fully be established by computed tomography, whereas ventriculography is no longer necessary.

Adolescent↗