Abstract
Background Ventriculoperitoneal (VP) shunt is still a mainstay of treatment in centers for infants
with aqueductal stenosis which is the most common cause of congenital obstructive
hydrocephalus. Shunt migration remains a common complication. Delayed distal shunt
tip migration into the thoracic cavity due to negative intrathoracic pressure is a
rare occurrence.
Case Presentation Authors report a 1-year-old infant presenting with drowsy sensorium, increasing head
circumference, and bulging anterior fontanelle. Magnetic resonance imaging of the
brain revealed significant obstructive hydrocephalus with periventricular seepage.
A large expansile diverticulum of the suprapineal recess extending infratentorially
compressing the dorsal midbrain and cerebellum inferiorly. The child underwent an
emergency right-side VP shunt (medium pressure) in view of clinical symptoms of raised
intracranial pressure. A right iliac fossa infraumbilical transverse incision was
taken for placing the abdominal end. Visual confirmation of bowel was done after opening
the peritoneum by two operating surgeons prior to inserting the distal catheter. Postoperative
course was uneventful. The child presented 3 months later with acute dyspnea and diminished
breath sounds on the right hemithorax. Neurologically, the child was active, feeding
well, and anterior fontanelle was lax. A chest roentgenogram and computed tomogram
(CT) of the thorax revealed complete shunt migration into the pleural space with significant
pleural effusion on the right side. The distal shunt system on CT appeared to enter
the pleural space below the 8th rib, probably indicating that there was subcostal
tunneling of the shunt below the 8th rib space during the first surgery which was
inconspicuous and subsequently over a span of 3 months due to sucking effect of negative
intrathoracic pressure the shunt gradually migrated into the pleural cavity which
led to the effusion. An emergency VP shunt revision was performed. The distal end
below the chamber was retunneled subcutaneously into a new incision in the left paraumbilical
region. Postoperative chest and abdomen roentgenograms showed resolving effusion and
accurate shunt placement. The child required elective ventilation temporarily to tide
over the underlying lung collapse and an intercostal tube drainage for the cerebrospinal
fluid (CSF) hydrothorax for 2 days to aid in quicker weaning. The child was discharged
on the 5th postoperative day.
Discussion Intrapleural migration of VP shunts has been contemplated to be due to trauma during
surgery, migration across foramen of Bochdalek or Morgagni, and negative intrathoracic
pressure. Taub and Lavyne have classified thoracic complications of VP shunt as thoracic
trauma during shunt tunneling, supradiaphragmatic migration of shunt or transdiaphragmatic
migration of shunt, and pleural effusion complicated by CSF ascites. Transdiaphragmatic
migration is commonly seen in pediatric population and supradiaphragmatic migration
can be seen in any age group. We believe our case to be a type of supradiaphragmatic
migration of the shunt which has occurred slowly over a span of time due to the negative
intrathoracic pressure. The idea behind this clinical case image is to edify neurosurgeons,
pediatricians, and intensivists to remain wary of such a complication.
Keywords
CSF flow problem - hydrocephalus - neurology - neurosciences - neurosurgery - pediatrics
