Etiology: placed in patients who require long-term decompression of hydrocephalus
Imaging: superior catheter tip should be intraventricular in location, inferior catheter tip should be freely floating within the peritoneum, normal to see small amount of free fluid in pelvis, ventricles should not be dilated
Complications: shunt broken or discontinuous or kinked or occluded, shunt tip migration out of ventricle, shunt tip intraparenchymal, shunt infection, over-shunting (slit-like ventricles), CSFoma
Treatment: shunt replacement except in cases of shunt infection which require temporary shunt diversion before shunt replacement
Clinical: presents with headaches / sommulence / irritability, shunt infection presents with fever, CSFoma presents with abdominal mass
AP and lateral radiographs of the abdomen shows the distal portion of the VP shunt to be broken into multiple fragments.AP radiograph of the skull shows a discontinuity between the tip of the VP shunt and the rest of the VP shunt. Axial, coronal, and sagittal CT without contrast of the brain shows marked hydrocephalus with transependymal flow of cerebrospinal fluid.AP and lateral radiographs of the skull and an AP radiograph of the abdomen shows a discontinuity between the reservoir of the VP shunt in the neck and the remainder of the VP shunt in the abdomen.AP and lateral radiographs of the skull show a kink in the VP shunt in the middle of the neck.AP and lateral radiographs of the skull shows migration of the VP shunt catheter tip out of its right-sided burr hole in the skull.AXR (above) shows the tip of the VP shunt has migrated into the right scrotum. Transverse US image (below) shows a moderate left hydrocele and the round VP shunt catheter in the medial aspect of the right scrotum.Axial CT without contrast of the brain obtained postoperatively shows a VP shunt catheter placed from a right parietal approach whose tip lies within the brain parenchyma.Axial T2 MRI without contrast of the brain (above) obtained 2 months ago shows normal ventricular size with a VP shunt in place. Axial CT without contrast of the brain (below) shows interval marked dilation of the lateral and third ventricles with transependymal flow of cerebrospinal fluid. The VP shunt series showed no radiographic abnormality of the VP shunt.Axial CT without contrast of the brain shows a low density fluid collection around the VP shunt reservoir between the skull and the scalp. In the operating room this fluid was found to be pus.Axial CT with contrast of the brain shows subependymal enhancement throughout the ventricular system.AP and lateral radiographs of the abdomen show the VP shunt to be coiled upon itself and there is a suggestion of a retrogastric mass on the lateral view. Transverse US of the left upper quadrant of the abdomen shows a large cystic structure with the VP shunt tip within it.Axial CT with intravenous and oral contrast of the abdomen shows an extremely large mass filling the abdomen with the tip of the VP shunt within it which is causing hydronephrosis and displacement of the bowel.Initial axial CT without contrast of the brain (above) showed marked dilation of the lateral, third and fourth ventricles. Axial CT without contrast of the brain 1 day after shunt placement (below) shows interval decompression of the ventricular system and interval development of large bilateral subdural hygromas.
