Thorough knowledge of the anatomic and (patho)physiologic characteristics of the vertebral venous system is mandatory for all physicians that participate in percutaneous vertebroplasty and kyphoplasty. To reduce the risk of cement extrusion into the vertebral venous system during injection, vertebral venous pressure should be increased during surgery. This can be achieved by operating the patient in the prone position and by raising intrathoracic venous pressure with the aid of the anesthesiologist during intravertebral instrumentation and cement injection. Intensive theoretical and practical training, critical patient selection, and careful monitoring of the procedures, also taking into account patient positioning and intrathoracic and intra-abdominal pressures, will help to facilitate low morbidity outcomes in these very promising minimally invasive techniques.

The morphology of the anterior and posterior internal vertebral venous plexus (IVVP) in human fetuses between 21-25 weeks of gestational age is described. The results are compared to the findings of a previous morphological study of the IVVP in the aged. The morphological pattern of the anterior IVVP in the fetus is very similar with the anterior IVVP in the aged human. In contrast, the posterior IVVP in the fetus lacks the prominent transverse bridging veins that are present in the aged lower thoracic and the lumbar posterior IVVP. The background of these morphological differences is unclear. Maybe the thoracolumbar part of the posterior IVVP is subject to "developmental delay," or the observed differences in the aged may result from functional and age-related factors that trigger this part of the vertebral venous system during (erect) life. The observed age related morphological differences of the posterior IVVP support the concept of the venous origin of the spontaneous spinal epidural hematoma (SSEH).

Chylothorax is a rare clinical entity characterized by a milky white aspirate with increased triglyceride levels. The commonest aetiology is malignancy and trauma. Pulmonary tuberculosis is an extremely rare cause of chylothorax. Two children with chylothorax and pulmonary tuberculosis are described. One child had bilateral and the other unilateral chylous effusions. Extensive mediastinal and hilar lymphadenopathy was demonstrated. Diseased lymph nodes may infiltrate other intrathoracic structures such as the thoracic duct, and they can also obstruct the cisterna chyli and thoracic duct. A possible explanation for the development of a chylothorax in our patients is obstruction of the thoracic duct by tuberculous lymphadenopathy with subsequent increase in pressure in the surrounding lymphatic system and leaking of chyle into the pleural space.

Renal tuberculosis is relatively uncommon in children. Imaging of renal tuberculosis in children differs from adults in that intravenous urography is rarely performed for urinary symptoms in childhood because of radiation dose considerations. Modern imaging modalities include cross-sectional techniques such as ultrasound, CT and MRI, which successfully show renal, calyceal, ureteric and bladder pathology of renal tuberculosis in children.