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D C Widenka

Publications and source records attributed to D C Widenka.

5 recordsLinked to original sources
PubMed1999

BrainLab VectorVision Neuronavigation System: technology and clinical experiences in 131 cases.

OBJECTIVE: The BrainLab VectorVision neuronavigation system was used in 131 cases of different brain pathological conditions. The neuronavigation system was used without problems in 125 cases. These cases included 114 microsurgical operations, 4 endoscopic procedures, 4 frameless stereotactic biopsies, and 3 catheter placements. METHODS: The BrainLab VectorVision neuronavigation system is an intraoperative, image-guided, frameless, localization system. The system consists of a computer workstation for registration of images and physical spaces, an intraoperative localization device, and a computer image display. The system provides real-time responses regarding the locations of surgical instruments. VectorVision is based on passive reflections of infrared flashes. Universal adapters with reflective markers for surgical instruments, endoscopes, and the operating microscope are used. RESULTS: In six cases, the system could not be used because of system failure or mishandling. In 125 neurosurgical cases, the neuronavigation system was useful, with a target-localizing accuracy of 4+/-1.4 mm (mean+/-standard deviation). For small cerebral lesions, we never performed an exploration with negative results. CONCLUSION: The BrainLab neuronavigation system has been shown to be very helpful and user-friendly for routine neurosurgical interventions. Its advantage lies in its mobility, based on wireless reflective adapters for surgical instruments, endoscopes, and the operating microscope.

Biopsy↗
PubMed1999

Treatment of carotid tandem stenosis by combined carotid endarterectomy and balloon angioplasty: technical case report.

OBJECTIVE AND IMPORTANCE: Cervical internal carotid artery disease associated with high-grade carotid siphon stenosis poses a therapeutic challenge. This report describes the combination therapy of carotid end-arterectomy and intraoperative transluminal balloon angioplasty of the carotid siphon. CLINICAL PRESENTATION: A 67-year-old man sustained repeated left hemispheric and retinal transient ischemic attacks. Results of a diagnostic examination, including angiography, disclosed a 70% ulcerative stenosis of the left extracranial internal carotid artery as well as a 90% stenosis of the left intracavernous carotid artery. The decision was made for combined open and endovascular therapy. INTERVENTION: After standard endarterectomy, an introducer for the dilation catheter was placed into the common carotid artery before final closure of the arteriotomy and recirculation. Under intraoperative fluoroscopy, a 3-mm dilation balloon was navigated into the carotid siphon stenosis and inflated several times. A 30% residual stenosis in the carotid siphon was obtained as a final result. The intervention was completed without complications. No further neurological symptoms were observed during the follow-up period of 30 months. CONCLUSION: Carotid endarterectomy, combined with intraoperative transluminal angioplasty of carotid siphon stenosis, is a feasible procedure for selected patients with carotid tandem stenosis.

Aged↗
PubMed1999

Inducible nitric oxide synthase: a possible key factor in the pathogenesis of chronic vasospasm after experimental subarachnoid hemorrhage.

OBJECT: The role of nitric oxide (NO) in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH) is not well understood. Nitric oxide is a well-established vasodilatory substance; however, in SAH, NO may become a major source for the production of injurious free-radical species, leading to chronic cerebral vasospasm. Reactive overproduction of NO to counteract vascular narrowing might potentiate the detrimental effects of NO. The focus of the present study is to determine the extent of reactive induction of inducible nitric oxide synthase (iNOS) after experimental SAH. METHODS: Chronic vasospasm was induced in male Wistar rats by an injection of autologous blood (100 microl) into the cisterna magna followed by a second injection 24 hours later. A control group of 10 animals was treated with injections of 0.9% sodium chloride solution. Vasospasm was verified by pressure-controlled angiography after retrograde cannulation of the external carotid artery 7 days later. In 11 of 15 animals radiographic evidence of cerebral vasospasm was seen. The animals were perfusion fixed and their brains were removed for immunohistochemical assessment. With the aid of a microscope, staining for iNOS was quantified in 40-microm floating coronal sections. Immunohistochemical staining for iNOS was markedly more intense in animals with significant angiographic evidence of vasospasm. Virtually no staining was observed in control animals. Seven days after the second experimental SAH, labeling of iNOS was found in endothelial cells, in vascular smooth-muscle cells, and, above all, in adventitial cells. Some immunohistochemical staining of iNOS was observed in rod cells (activated microglia), in glial networks, and in neurons. CONCLUSIONS: The present study demonstrates induction of iNOS after experimental SAH.

Animals↗