Mark A Davies

Publications (3)5.86 Total impact

• Article: Is bone scintigraphy necessary in the initial surgical staging of chondrosarcoma of bone?

  Hassan Douis, Steven L James, Robert J Grimer, Mark A Davies
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  ABSTRACT: To assess the value of whole-body bone scintigraphy in the initial surgical staging of chondrosarcoma of bone. A retrospective review was conducted of the bone scintigraphy reports of a large series of patients with peripheral or central chondrosarcoma of bone treated in a specialist orthopaedic oncology unit over a 13-year period. Abnormal findings were correlated against other imaging, histological grade and the impact on surgical staging. A total of 195 chondrosarcomas were identified in 188 patients. In 120 (63.8%) patients the reports of bone scintigraphy noted increased activity at the site of one or more chondrosarcomas. In one patient the tumour was outside the field-of-view of the scan, and in the remaining 67 (35.6%) cases, there was increased activity at the site of the chondrosarcoma and further abnormal activity in other areas of the skeleton. Causes of these additional areas of activity included degenerative joint disease, Paget's disease and in one case a previously undiagnosed melanoma metastasis. No cases of skeletal metastases from the chondrosarcoma were found in this series. Multifocal chondrosarcomas were identified in three cases. In two it was considered that all the tumours would have been adequately revealed on the initial MR imaging staging studies. In only the third multifocal case was an unsuspected, further presumed low-grade, central chondrosarcoma identified in the opposite asymptomatic femur. Although this case revealed an unexpected finding the impact on surgical staging was limited as it was decided to employ a watch-and-wait policy for this tumour. There is little role for the routine use of whole-body bone scintigraphy in the initial surgical staging in patients with chondrosarcoma of bone irrespective of the histological grade.
  Skeletal Radiology 09/2011; 41(4):429-36. · 1.54 Impact Factor
• Article: Positional vomiting due to a thoracic spinal dural arteriovenous fistula. Case report.

  Dennis J Cordato, Mark A Davies, Lynette T Masters, Phillp D Cremer, Raymond S Schwartz, William Sorby, Zoran Becvarovski
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  ABSTRACT: The authors report the unique case of a patient with a thoracic spinal dural arteriovenous fistula (DAVF) causing remote brainstem symptoms of positional vomiting and minimal vertigo. Magnetic resonance (MR) imaging of the brain demonstrated high signal abnormality in the medulla, presumably related to venous hypertension, and spinal MR imaging revealed markedly dilated veins along the dorsal aspect of the cord. Spinal angiography confirmed the presence of a thoracic spinal DAVF. Disconnection of the DAVF from the spine resulted in a marked improvement in symptoms and resolution of the preoperative MR imaging-documented abnormalities. The authors highlight the rare syndrome of positional vomiting as a brainstem symptom and conclude that spinal DAVFs should be considered in the differential diagnosis of high signal MR imaging abnormalities localized to the brainstem.
  Journal of Neurosurgery Spine 10/2004; 1(2):219-22. · 1.53 Impact Factor
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  Available from: sydneyspineclinic.com.au

  Article: Death after late failure of endoscopic third ventriculostomy: a potential solution.

  Ralph J Mobbs, Marianne Vonau, Mark A Davies
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  ABSTRACT: Late failure after successful third ventriculostomy is rare, and death caused by failure of a previously successful third ventriculostomy has been reported on four occasions. We describe a simple innovation that adds little morbidity and has the potential to reduce the advent of death after late failure of endoscopic third ventriculostomy. After endoscopic fenestration of the floor of the third ventricle, a ventricular catheter and subcutaneous reservoir are placed via the endoscope path. With acute blockage and neurological deterioration, cerebrospinal fluid can be removed via needle puncture of the reservoir until consultation with a neurosurgeon. From 1979 to 2003, more than 240 endoscopic third ventriculostomies have been performed at our institution, with one death after late failure. The revised technique was devised after this death and has been performed on 21 patients to date. The addition of a reservoir adds little time and morbidity to the procedure and offers the potential to sample cerebrospinal fluid, measure intracranial pressure, and reduce mortality associated with late failure of endoscopic third ventriculostomy.
  Neurosurgery 09/2003; 53(2):384-5; discussion 385-6. · 2.79 Impact Factor