Etiology: Ventriculoperitoneal (VP) shunt 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
Note: — Shunt malfunction can be caused by shunt valve dysfunction or shunt valve failure, catheter disruption, catheter fracture or CSFoma = cerebrospinal fluid pseudocyst — Discontinuity of ventriculoperitoneal shunt can be difficult to identify especially if discontinuity is at the shunt reservoir so do not forget to look at comparison studies — Check entire length of a ventriculoperitoneal shunt for fracture or discontinuity on every study — Look for a change in ventricular size on HCT or MRI to determine if a shunt malfunction is present — Remember to look at shunt valve setting on shunt series with programmable shunt valves to make sure they are similar — With overshunting look for decreased ventricular volumes compared to prior and overshooting occasional causes subdural hematomas
Complications: — Ventriculoperitoneal shunt broken or discontinuous or kinked or occluded — Ventriculoperitoneal shunt no longer intraperitoneal due to patient growing — Ventriculoperitoneal shunt tip migration out of ventricle — Ventriculoperitoneal shunt tip intraparenchymal — Intraparenchymal pericatheter cysts — Ventriculoperitoneal shunt infection — Over-shunting (slit-like ventricles) — CSFoma
Treatment: Ventriculoperitoneal shunt replacement except in cases of ventriculoperitoneal shunt infection which require temporary ventriculoperitoneal shunt diversion before ventriculoperitoneal shunt replacement
Clinical: — Presents with headaches or sommulence or irritability — Ventriculoperitoneal shunt infection presents with fever — CSFoma presents with abdominal mass
Radiology Cases of Ventriculoperitoneal Shunt Broken
Lateral radiograph of the skull taken 7 years ago (above) shows the VP shunt to be intact inferior to the lucent shunt reservoir. Current lateral radiograph of the skull (below) shows a discontinuity in the ventriculoperitoneal shunt inferior to the lucent shunt reservoir due to a breakage of the shunt tubing.AP and lateral radiographs of the abdomen shows the distal portion of the VP shunt to be broken into multiple fragments.Axial CT without contrast of the brain (above left) shows the tip of the ventriculoperitoneal shunt to be in the center of dilated lateral ventricles, and that the dilated ventricles are a new finding when compared to the axial T2 MRI without contrast of the brain from 1 year ago (above right). AXR from a shunt series (below left) shows a discontinuity in the VP shunt in the right mid abdomen which is better demonstrated on the 3D CT of the abdomen (below right).
Radiology Cases of Ventriculoperitoneal Shunt Discontinuity
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.Lateral radiograph of the skull obtained after VP shunt placement 3 months ago (above) shows all of the parts of the VP shunt to be connected together. Current lateral radiograph of the skull (below) shows an increasing space between the superior portion of the VP shunt and the reservoir beneath it, thus the superior part of the VP shunt is disconnected from the reservoir.Lateral radiograph of the skull obtained 3 years ago (above) shows the ventriculoperitoneal (VP) shunt tubing that courses inferiorly is connected appropriately to the radiolucent VP shunt reservoir. Lateral radiograph of the skull obtained today (below) shows interval development of increased distance between the VP shunt tubing that courses inferiorly and the radiolucent VP shunt reservoir due to interval development of a disconnection of the VP shunt tubing from the VP shunt reservoir.
Radiology Cases of Ventriculoperitoneal Shunt Kinked
AP and lateral radiographs of the skull show a kink in the VP shunt in the middle of the neck.
Radiology Cases of Ventriculoperitoneal Shunt Tip Migration Out of Ventricle
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.Axial T2 MRI without contrast of the brain immediately after ventriculoperitoneal shunt placement a week ago (left) shows the tip of the VP shunt placed from a left parietal approach to be in appropriate position in the the posterior horn of the left lateral ventricle. Axial T2 MRI of the brain from today (right) shows the tip of the ventriculoperitoneal shunt to no longer be within the left lateral ventricle but to be in the brain parenchyma.
Radiology Cases of Ventriculoperitoneal Shunt Tip Migration Into Scrotum
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.
Radiology Cases of Ventriculoperitoneal Shunt Tip Migration Into Chest
AXR taken 1 year ago (left) shows the VP shunt to be radiographically intact and its tip is coiled in the pelvis. AXR taken today (right) shows the VP shunt migrated out of the abdomen into the left chest and its tip is in the left costrophrenic angle.
Radiology Cases of Ventriculoperitoneal Shunt Tip Intraparenchymal
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.
Radiology Cases of Ventriculoperitoneal Shunt Occluded
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.
Radiology Cases of Ventriculoperitoneal Shunt Infected
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.
Radiology Cases of Ventriculoperitoneal Shunt CSFoma
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.Axial CT without contrast of the abdomen shows a VP shunt in the anterior right abdomen that is coursing between two low density fluid collections and whose tip is in the fluid collection nearest to the midline.Axial CT with contrast of the abdomen (above) shows the VP shunt anteriorly in the abdomen coursing through a multiloculated fluid collection on the left side of the abdomen. Coronal CT (below left) shows multiple dilated loops of proximal small bowel while the sagittal CT (below right) shows the fluid collection to have at least 3 locules.Axial (above) and coronal (below) CT with contrast of the abdomen shows a round low density fluid collection in the subcutaneous tissues of the right anterior abdominal wall with inflammatory changes noted around the fluid collection. In the center of the fluid collection is a coiled ventriculoperitoneal shunt.
Radiology Cases of Ventriculoperitoneal Shunt Overshunting
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.Axial T2 MRI without contrast of the brain from 1 year ago (left) shows normal size of the anterior and posterior horns of the lateral ventricles. The tip of the ventriculoperitoneal shunt (not shown) was in a correct position. Axial T2 MRI without contrast of the brain from today (right) shows interval decrease in size of the anterior and posterior horns of the lateral ventricles which appear slit-like. The tip of the ventriculoperitoneal shunt (not shown) was in a correct position.Axial CT without contrast of the brain show a ventriculoperitoneal shunt entering from a right parietal approach whose tip projects over the anterior horn of the right lateral ventricle. The ventricular system is completely collapsed and cannot be seen.
