Biomedical subjects

Thomas Riegel

Publications and source records attributed to Thomas Riegel.

10 recordsLinked to original sources

PubMed2005

Secretory meningioma: immunohistochemical findings and evaluation of mast cell infiltration.

Secretory meningiomas constitute a relatively rare subtype of meningiomas, accounting for only 1.1% at our institution, with a 6:1 predominance of female patients. This study aimed to obtain more information about the immunohistochemical characteristics of this histological entity, and to analyse the effects of histological factors such as the presence of mast cells on the radiological evidence of surrounding tumour oedema that frequently occurred in this subtype of meningioma. Fourteen cases of secretory meningioma were examined. Relevant clinical information was obtained from the patient files. Peritumoural oedema was determined either by CT or MRI scans and graded as small, moderate and severe. In order to perform the quantitative evaluation of mast cells in secretory meningiomas in a comparison with other meningiomas, 14 non-secretory meningiomas were randomly selected and used as a control group. The immunohistochemical staining of carcinoembryonic antigen was positive within the secretory droplets and the cells surrounding them in all cases. Ki 67 (MIB 1) proliferative index mean values were 2.4%, indicating low expression in all secretory meningiomas. Moreover, from our statistical analysis, there is no clear-cut pattern of various types of cytokeratins emerging in secretory meningiomas. The secretory meningiomas were characterized by a significantly increased number of mast cells as compared with non-secretory meningiomas of different grades. As the present clinical findings and laboratory results could not confirm a correlation between mast cell density and radiological evidence of oedema, further studies of mediators are warranted.

Actins↗

PubMed2005

Enlarged perivascular spaces mimicking multicystic brain tumors. Report of two cases and review of the literature.

The authors present two cases in which enlarged Virchow-Robin spaces were located in the basal ganglia and the thalamomesencephalic region. The incidence of such huge cystic lesions is extremely rare. The expanding nature of these lesions, demonstrated by the patients' progressive symptoms due to compression of the adjacent brain parenchyma and obstructive hydrocephalus, mimicked that of brain tumors. The two patients were successfully treated by neuroendoscopic cystocisternostomy or ventriculocystostomy. To the authors' knowledge there have been only two published reports on expanding Virchow-Robin spaces that produced a compressive effect or consequent hydrocephalus and were directly fenestrated using neuroendoscopic techniques. Neuroendoscopy appears to offer an effective surgical option in the treatment of symptomatic Virchow-Robin spaces.

Basal Ganglia↗

PubMed2004

Endoscopic third ventriculostomy for obstructive hydrocephalus.

The indications for neuroendoscopy are not only constantly increasing, but even the currently accepted indications are constantly being adjusted and tailored. This is also true for one of the most frequently used neuroendoscopic procedures, the endoscopic 3rd ventriculostomy (ETV) for obstructive hydrocephalus. ETV has gained popularity and widespread acceptance during the past few years, but little attention has been paid to the techniques of the procedure. After a short introduction describing the history of ETV, an overview is given of all the different techniques that have been and still are employed to open the floor of the 3rd ventricle. The spectrum of indications for ETV has been widely enlarged over the last years. Initially, the use of this procedure was restricted to patients older than 2 years, to patients with an obvious triventricular hydrocephalus, and to those with a bulging, translucent floor of the 3rd ventricle. Nowadays, indications include all kinds of obstructive hydrocephalus but also communicating forms of hydrocephalus. The results of endoscopic procedures in treating these pathologies are given under special consideration of shunt technologies. In summary, from the review of the publications since the first ETV performed by Mixter in 1923, this technique is the treatment of choice for obstructive hydrocephalus caused by different etiologies and is an alternative to cerebrospinal fluid shunt application.

Age Factors↗

PubMed2004

The evolution of stereotactic guidance in neuroendoscopy.

OBJECTIVES: To evaluate the advantages and limitations of the utilized system in accordance with the operative indications of stereotactic neuroendoscopy. PATIENTS AND METHODS: We reviewed our collective experience of computer-assisted stereotaxy (frame-based and frameless) and virtual endoscopy in neuroendoscopic surgery from 1982 to 2003. Sterotactic guiding systems (frame-based and frameless) have been used to perform more than 450 neuroendoscopic operations at our institute. RESULTS: Even though image guidance is not essential in all cases, technological developments have definitely been one of the major factors in improving outcomes. Planning endoscopic trajectory and intraoperative orientation within the ventricular system or other cavities are the main indications for its application. CONCLUSIONS: No surgical tool, no matter how accurate, can be a substitute for thoughtful and methodical pre-operative planning. Image-guided technologies are applied in order to make endoscopic surgery safer, faster and more easily reproducible. Despite the high initial cost of the equipment, overall expenses are expected to be reduced because of greater operative efficiency and shorter hospital stay.

Adolescent↗

PubMed2004

Neuroendoscopic stent procedure in obstructive hydrocephalus due to both foramina of monro occluding craniopharyngioma: technical note.

BACKGROUND: The development of various neuroendoscopic surgical instruments has offered more options for endoscopic procedures in the treatment of intraventricular tumors. Not only tumor biopsy or tumor resection but also restoration of an obstructed cerebral spinal fluid (CSF) pathway can be performed using the same approach. METHOD: A 76-year-old woman with a cardiac pacemaker for an underlying heart disease was diagnosed with obstructive hydrocephalus because of a third ventricular tumor 8 years ago. The patient had been treated with ventriculo-peritoneal shunt placement. At admission she presented with a subcutaneous infection of the shunt catheter and an abdominal mass of unknown etiology. Neuroendoscopic stenting between lateral and third ventricle was performed to restore the obstructed CSF pathway, and the infected shunt system was removed in the same setting. RESULT: The postoperative course was uneventful. Contrast ventriculography demonstrated a restored CSF pathway between the lateral and third ventricle. Histologic examination of the intraventricular tumor revealed a craniopharyngioma, and the abdominal mass was diagnosed as a gastrointestinal adenocarcinoma. CONCLUSION: The neuroendoscopic foraminoplasty technique should be considered as an alternative treatment for patients who present with an obstructive hydrocephalus caused by a tumor that occludes both foramina of Monro when shunt placement or endoscopic third ventriculostomy is not feasible.

Adenocarcinoma↗

PubMed2003

Isolated paramedullary hemangioblastoma originating from the first cervical nerve root: case report.

STUDY DESIGN: A retrospective case of an isolated paramedullary hemangioblastoma originating from the first cervical root is reported. OBJECTIVE: To describe an uncommon type of spinal hemangioblastoma and its operative treatment. SUMMARY OF BACKGROUND DATA: Spinal hemangioblastoma, rare finding accounting for approximately 1.5% to 2.5% of all spinal cord tumors, may have an intramedullary, extramedullary, or extradural location. Cervical hemangioblastomas occur in approximately 45% of the cases and are intramedullary in about 83% of the cases. METHODS: A 59-year-old man presented with acute subarachnoid hemorrhage in the basal cisterns. Four-vessel angiography showed a highly vascular small tumor at the dorsolateral side of the cervicomedullary junction fed by a branch of the vertebral artery. The lesion was surgically removed. RESULTS: Total removal of the lesion was achieved after identification of both the arterial feeder and the draining vein with the aid of microvascular Doppler sonography. There were no complications, and the patient did well after surgery. CONCLUSIONS: Although hemangioblastomas occurring in the cervicomedullary area usually may cause progressive neural compression, occasionally they also can present clinically as acute subarachnoid hemorrhage. This situation requires urgent and adequate treatment as in the reported case.

Acute Disease↗

PubMed2003

Neuroendoscopic treatment for colloid cysts of the third ventricle: the experience of a decade.

OBJECTIVE: Microsurgical resection or ventriculoperitoneal shunt placement was for a long time the only means of treatment for patients with colloid cysts. In the past few years, however, endoscopic procedures have gained increasing significance and have been used more widely. Long-term results are now available for the first time, which enabled us to evaluate this method and assess its future relevance. METHODS: Twenty patients with symptomatic colloid cysts of the third ventricle have been treated endoscopically in our department during the past 10 years. Retrospective analysis and follow-up of the patients' clinical and radiological outcomes were performed. RESULTS: In the early postoperative period, 18 patients had excellent outcomes, with clinical signs improving immediately. One patient experienced intraoperative hemorrhage followed by temporary postoperative psychosis and IIIrd cranial nerve palsy. Another patient remained shunt-dependent because of aseptic meningitis after the endoscopic procedure. In the long-term follow-up, one patient had to be reoperated to treat cyst recurrence. The operative time was strongly dependent on the cyst material as well as on the surgeon's experience with endoscopic techniques; it varied between 60 and 300 minutes (mean operative time, 200 min). The average hospitalization time was 9 days. Long-term follow-up ranging from 1 to 10 years showed a clear benefit in each patient. In three individuals with pre- and postoperative short-term memory deficits and in one patient who complained of headaches, symptoms resolved gradually during the first few months after surgery. The patient with intraoperative hemorrhage complained of slight permanent short-time memory deficit. The analysis of postoperative computed tomographic and magnetic resonance imaging scans revealed a remaining cyst wall in the majority of patients and an inconsistent decrease in ventricular size. Postoperative cine magnetic resonance imaging studies showed normalization of cerebrospinal fluid flow in 17 patients. CONCLUSION: Continued improvement of endoscopic techniques and instruments, together with good long-term results in endoscopically treated patients, have established this method as an alternative to microsurgical techniques and might even set a new standard for treatment.

Adolescent↗

PubMed2002

Successful management of a symptomatic fusiform dilatation of the internal carotid artery following surgery of childhood craniopharyngioma.

INTRODUCTION: The development of fusiform dilatation of internal carotid artery is one of the vascular complications that can follow surgery for craniopharyngioma and other suprasellar tumours in children, but its pathogenesis and the line of management are still controversial. CASE REPORT AND DISCUSSION: We report a child who presented with a giant fusiform aneurysm involving the supraclinoid portion of the internal carotid artery after total removal of a craniopharyngioma and review the literature on related cases. The treatment of this phenomenon and its possible pathogenesis are discussed.

Aneurysm↗

PubMed2002

Novel multipurpose bipolar instrument for endoscopic neurosurgery.

OBJECTIVE: Hemorrhage control in endoscopic neurosurgery is critical because of the lack of suitable instruments for coagulation. One reason for this problem is that miniaturization of the instruments is still a technical problem. In this article, we present a solution: the use of bipolar microforceps with a small diameter of 1.5 mm. METHODS: With the use of modern synthetic and metallic materials, the construction of the bipolar microforceps was designed without the use of mechanical joints. All movable elements are integrated within the instrument shaft. This design provides optimal visibility of the operating field because the sheath has a diameter of only 1.5 mm along its entire length. Therefore, this instrument is compatible with most working channels of neuroendoscopes. RESULTS: The new, joint-free design of the forceps and the electric insulation of the branches were the technical innovations that led to the development of this novel, multipurpose instrument. CONCLUSION: This new instrument may enhance endoscopic resection and shrinkage of cystic lesions and may offer new possibilities in endoscopic tumor resection and the treatment of hemorrhage.

Adult↗

PubMed2002

Image fusion for skull base neuronavigation. Technical note.

An automatic image fusion module (BrainLab, Munich, Germany) is used for the fusion of the magnetic resonance (MR) imaging and computed tomography (CT) data sets. The procedure of image fusion takes 5 minutes prior to surgery. The image fusion of CT and MR imaging data visualizes the skull base and tumor margins clearly. Color display of the different data sets allows the tumor and the skull base to be distinguished easily. The fused CT data in bone window mode provides useful additional information on the osseous skull base.

Brain Mapping↗