Volker Ziegler

Publications (2)2.55 Total impact

• Article: Does anatomical completeness of the circle of Willis correlate with sufficient cross-perfusion during unilateral cerebral perfusion?

  Paul P Urbanski, Aristidis Lenos, Juan C Blume, Volker Ziegler, Bernd Griewing, Rainer Schmitt, Anno Diegeler, Michael Dinkel
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  ABSTRACT: The aim of the study was to evaluate the role of anatomical completeness of the circle of Willis for sufficient brain perfusion during unilateral cerebral perfusion and the methodology of the preoperative and intraoperative functional assessments of adequate cross-perfusion. This prospective observational study included all elective patients (99) who underwent elective open arch surgery (hemiarch in 74 and arch replacement in 25 patients, respectively) at our institution between September 2004 and September 2006. Preoperative neuro-vascular evaluation included color-coded duplexsonography of the extracranial arteries, cranial CT angiography, and transcranial sonography. A functional test of cerebral cross-perfusion was performed during cross-clamping of the common carotid artery during cannulation by transcranial Doppler, electroencephalography and measurement of somatosensory evoked potentials. These examinations, which were completed through measurement of arterial pressure in both radial arteries, also served as an intraoperative assessment of cerebral perfusion during surgery. During mild hypothermic (30 degrees C) circulatory arrest with a mean duration of 18 min (range, 7-70) brain protection using unilateral cerebral perfusion was performed in all patients. As assessed in preoperative CT angiography, the circle of Willis was complete in only 59 patients. Eighteen patients showed a singular abnormal location within the circle of Willis, 13 patients presented with abnormalities within the posterior communicating arteries on both sides, and 9 patients within the anterior and posterior communicating arteries. Nevertheless, functional tests during carotid artery cross-clamping as well as intraoperative cerebral monitoring including transcranial Doppler showed no pathology in any patient, and only one patient with severe aortic valve calcification suffered from embolic minor stroke after surgery. The anatomical status of the circle of Willis assessed with cranial CT angiography does not correlate with functional and intraoperative tests examining the cerebral cross-perfusion. The authors do not recommend cranial CT angiography as a preoperative standard examination before open arch surgery in which unilateral cerebral perfusion is scheduled.
  European Journal of Cardio-Thoracic Surgery 04/2008; 33(3):402-8. · 2.55 Impact Factor
• Article: [Clinical symptoms and diagnostic imaging in moyamoya disease].

  Georgios Christopoulos, Volker Ziegler, Günther Coblenz, Eberhard Wedell, Bernd Griewing, Rainer Schmitt
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  ABSTRACT: Presentation of typical imaging findings and diagnostic approaches in patients suspected of moyamoya disease. Two female patients (24 resp. 44 years old) presenting with equivocal neurological symptoms (headache, recurrent monoparesis, choreiformic ataxia, grand mal seizure) were examined by means of colour-coded ultrasound, selective catheter-based angiography (DSA), CT and MRI including MR angiography. Cranial CT and MRI showed normal findings in one patient, and focal cerebral infarctions of different age in the other. In both cases, colour-coded ultrasound was indicative in detecting occlusive disease of the internal carotid arteries. Both, MR angiography as well as catheter-based angiography revealed the pathology of the culprid vessel, in addition catheter-based angiography was more accurate in depicting moyamoya collaterals at the skull base. In moyamoya disease colour-coded ultrasound is diagnostic for the lesion of the internal carotid artery, MRI resp. MRA depict the vascular and parenchymal lesion, whereas catheter-based DSA by providing information about the main vessel and collateral system allows the staging of the disease.
  Rontgenpraxis 02/2003; 55(1):39-45.