Keywords
extradural - hematoma - hydrocephalus - subdural - ventriculoperitoneal shunt
Introduction
Ventriculoperitoneal (VP) shunt surgery is a very common neurosurgical procedure in the continuum of relatively high prevalence of hydrocephalus in our country. In the Indian context, VP shunts are most commonly used to treat hydrocephalus.[1] Shunt surgeries are associated with many complications. Excessive drainage is one of those complications which has significant impact on the neurological status of the patients. Chronic subdural hematoma (SDH) and extradural hematoma (EDH) are potentially life-threatening complications of excessive drainage occurring usually over different time periods.[2]
[3] Occurrence of both entity simultaneously in a patient is extremely rare. Hereby, we report a case of a 12-year-old boy who presented to the emergency room in altered sensorium and gradual onset quadriparesis following multiple shunt revision for congenital hydrocephalus secondary to aqueductal stenosis and his initial computed tomography (CT) head scans showed simultaneous occurrence of chronic SDH on the right side and EDH on the left side.
Discussion
VP shunt is a very common neurosurgical procedure done for hydrocephalus due to various etiologies in different age groups. Shunt surgery and its complications are integral part of each other.[4] Intracranial hematomas are rare set of complications associated with VP shunt surgeries.[5] Intracranial hematoma can be in the form of acute or chronic SDH, EDH, or intracerebral hematoma. SDHs among these are more common.[6]
[7] SDHs can occur in up to 2 to 17% patients with cerebrospinal fluid diversion procedures.[8] Mechanisms to explain formation of intracranial hematomas are not precisely defined yet, but some concepts have been postulated. Following VP shunt surgery, ventricles shrinkage lead to the collapse of brain cortex inwards. It causes stretching of the bridging veins which are amenable to rupture even after minor trauma.[8] Other causes may be bleeding disorders or use of anticoagulants.[6]
[7]
[8] Formation of EDH following shunt surgeries is extremely rare. It may be at the surgical site or distant from the surgical site.[9] Dural separation during ventricular catheter insertion or collapse of cortex following drainage of ventricle leads to pressure on dural venous attachment which may bleed further. Repeated attempt of ventricular catheter insertion without adequate durotomy may lead to the separation of dura from calvarium and delayed manifestation in the form of EDH secondary to dural vessels oozing. Inadequate hemostasis of dural margins or bone, bleeding diathesis, or venous malformations are the other causes.[9]
[10]
In our case, gradual collapse of the cortex on the right side following VP shunt surgery led to the formation of chronic SDH. Rapid shrinkage of ventricle followed by collapse of the cortex and inadequate hemostasis of dural margins were probable causes of EDH formation on the left side.
Although chronic SDHs have gradual progression, patients may remain asymptomatic but rapid neurological deterioration can occur in case of EDH. In our case, EDH formation after shunt revision led to rapid neurological deterioration for which emergency surgery was required.
Few cases have been reported of isolated chronic SDH or EDH following VP shunt placement. We are probably one of the first authors to report such case of simultaneous occurrence of chronic SDH and EDH in a patient following shunt procedures.
Conclusion
VP shunt surgeries are associated with many complications. SDH and EDH are potentially life-threatening complications. Adequate hemostasis along with accurate surgical technique is of paramount importance in shunt surgeries. In case of neurological deterioration following shunt surgeries, high index of suspicion should be made and immediate CT scans are required to rule out these fatal entities. Prompt diagnosis and appropriate surgical intervention lead to excellent outcome.
