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Biomedical subjects

Ulrich Sure

Publications and source records attributed to Ulrich Sure.

26 records · Page 2Linked to original sources
PubMed2004

Immunohistochemical study in dural arteriovenous fistula and possible role of ephrin-B2 for development of dural arteriovenous fistula.

BACKGROUND: Although there were several clinical and experimental studies discussing the pathogenesis of dural arteriovenous fistula (DAVF), the pathological process leading to intracranial DAVF so far remains unknown. In this study, we investigated the expression of vascular growth factors in order to elucidate the possible role of these factors for the development of DAVF and to study the biological activity of this uncommon lesion. METHODS: We examined the histological features, proliferative and angiogenic capacities of the tissue specimens obtained from 6 patients who underwent surgery at our institution. Immunohistochemical staining for vascular endothelial growth factor (VEGF), its receptors Flk-1 and Flt-1, ephrin-B2, MIB-1 and proliferating cell nuclear antigen (PCNA) was performed using standard immunohistochemical techniques. RESULTS: A positive immunostaining was found for all antibodies studied except MIB-1, whereas nuclear endothelial expression of PCNA was observed in only 3/6 cases. VEGF stained positive in all of the available specimens (6/6). Flk-1 showed a positive immunoreaction in only 2/6 cases and Flt-1 in 4/6 cases. Ephrin-B2 was expressed in the majority (5/6) of the cases. CONCLUSIONS: These results support the hypothesis that DAVFs might be acquired dynamic vascular malformations with low biological activity. Vascular growth factors like VEGF and ephrin-B2 might play a pivotal role in the formation of DAVF.

Aged↗
PubMed2003

Intraoperative spinal digital subtraction angiography: technique and results.

OBJECTIVE: To evaluate technical and methodological aspects of intraoperative spinal digital subtraction angiography (ISDSA) in our clinical practice and to assess its practicability, safety, and accuracy for the surgical treatment of spinal vascular malformations. METHODS: Between August 1997 and February 2002, a total of 30 patients were treated either surgically (n = 18) or endovascularly (n = 12) for spinal vascular lesions at our institution. The clinical records of five patients who underwent ISDSA were analyzed retrospectively. The thoracic segment was involved in three patients and the medullary cone in two. RESULTS: ISDSA could be performed in four cases. In one patient, the segmental artery could not be probed sufficiently while the patient was prone. No complications occurred from the application of ISDSA. The method was beneficial for the neurosurgeon in all but one patient because the vascular anatomy of the malformation was shown with respect to the surgical approach, including the nidus, and immediate resection control could be performed before wound closure. The duration of the procedure was prolonged by 45 minutes on average. CONCLUSION: ISDSA is safe and effective, especially in surgery for complex vascular and recurrent malformations. Benefits to the patient outweigh the additional expense and prolongation of the surgical procedure.

Adolescent↗
PubMed2003

Image-guided transsylvian, transinsular approach for insular cavernous angiomas.

OBJECTIVE: Surgical treatment of cavernomas arising in the insula is especially challenging because of the proximity to the internal capsule and lenticulostriate arteries. We present our technique of image guidance for operations on insular cavernomas and assess its clinical usefulness. METHODS: Between 1997 and 2003, with the guidance of a frameless stereotactic system (BrainLab AG, Munich, Germany), we operated on eight patients who harbored an insular cavernoma. Neuronavigation was used for 1) accurate planning of the craniotomy, 2) identification of the distal sylvian fissure, and, finally, 3) finding the exact site for insular corticotomy. Postoperative clinical and neuroradiological evaluations were performed in each patient. RESULTS: The navigation system worked properly in all eight neurosurgical patients. Exact planning of the approach and determination of the ideal trajectory of dissection toward the cavernoma was possible in every patient. All cavernomas were readily identified and completely removed by use of microsurgical techniques. No surgical complications occurred, and the postoperative course was uneventful in all patients. CONCLUSION: Image guidance during surgery for insular cavernomas provides high accuracy for lesion targeting and permits excellent anatomic orientation. Accordingly, safe exposure can be obtained because of a tailored dissection of the sylvian fissure and minimal insular corticotomy.

Adult↗
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

Cerebral cavernomas in the adult. Review of the literature and analysis of 72 surgically treated patients.

The authors review the pertinent literature dealing with all aspects of cerebral cavernous malformations in the adult. Clinical, neuroradiological, pathological, and epidemiological aspects are presented. The clinical significance of bleeding from cavernous malformations and various hemorrhage patterns are discussed in relation to the factors that influence hemorrhage rates. Recent reports describing the genetic mechanisms of inheritance, de novo formation, and angiogenesis of cavernomas are reviewed as well. Brainstem cavernomas have received special attention, since their clinical management is controversial in the literature. Presently, microsurgical removal is favored by the majority of authors and stereotactic radiosurgery appears to be inappropriate for prevention of bleeding from a cavernoma. Our own case material consists of data of 72 patients operated upon during the past 5 years. Twenty-four patients harbored the lesion within the brainstem, 18 within the deep white matter of the hemispheres, 12 in the basal ganglia or thalamus, 11 in superficial areas of the hemisphere, and seven within the cerebellum. The perioperative morbidity rate was 29.2% (21/72) while the rate of long-term morbidity was 5.5% (4/72), with no mortality in this series. It is concluded that cerebral cavernous malformations, including lesions in critical regions of the brain, can be treated microsurgically with excellent results and an acceptable morbidity.

Brain Neoplasms↗
PubMed2002

Role of nitric oxide in the regulation of spinal arteriolar tone.

OBJECTIVE: The important role played by nitric oxide (NO) in the maintenance of cerebral arterial tone, both in the resting state and after injury, has been demonstrated, but the role of NO in spinal arteries is unknown. The aim of this study was to verify, by topical application of a NO synthase inhibitor in vivo, the hypothesis that NO plays an important role in the maintenance of spinal arteriolar tone. METHODS: Closed spinal windows were prepared at the C6 level, for observation of arteriolar reactivity. Male Wistar rats were divided into four groups in the resting state and three groups in the compressed state (which was produced by increasing the intrathecal window pressure). The control group underwent superfusion of artificial cerebrospinal fluid into the spinal window. The nitro-L-arginine-methyl ester (L-NAME) and nitro-D-arginine-methyl ester groups underwent superfusion of the NO synthase inhibitor L-NAME and its inactive enantiomer nitro-d-arginine-methyl ester, respectively. The L-NAME/S-nitroso-acetylpenicillamine (SNAP) group underwent mixed superfusion of L-NAME and the direct NO donor SNAP, for investigation of the effects of an exogenous NO donor. RESULTS: In the resting state, the arterioles constricted significantly in the L-NAME group, compared with values before L-NAME superfusion and those for the other groups. In the L-NAME/SNAP group, the arterioles dilated significantly after SNAP superfusion, compared with values before superfusion and those for the other groups. In the compressed state, the arterioles dilated after compression in all three groups but the dilation was significantly attenuated in the L-NAME group, compared with values for the control and nitro-D-arginine-methyl ester groups. CONCLUSION: It is suggested that NO plays an important role in the maintenance of spinal arteriolar tone in the resting and compressed states of the spinal cord.

Animals↗
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↗