Supratentorial Epidural Hematoma after Posterior Fossa Surgery
Non-traumatic, non-arterial origin delayed Epidural Hematoma after posterior fossa surgery is extremely rare. Moreover, the pathogenesis of its supratentorial extension is obscure.
The possible causes include sudden decompression of ventricular pressure in the supratentorial compartment, rupture of cortical veins in the sitting position, coagulopathy, hemodynamic fluctuations during surgery, and position-related ischemia 1).
The lowering of the ventricular pressure by the ventricular tapduring the operation may play significant role in the formation of the extradural hematoma.
The younger age of the cases and the long history of increased intracranial pressure were stressed in the literature2).
Wolfsberger et al., stressed the importance of early postoperative CT scan and optimal management of ventricular pressure and coagulation status to detect and prevent this possibly life-threatening complication 3).
Avci et al., from Mersin, reported a case during removal of a huge Posterior fossa dermoid cyst 4).
Pandey et al., from Bangalore reported in 2008 a large bifrontal extradural hematoma following posterior fossa surgery for a vermian medulloblastoma. 5).
Tsugane et al., reported five cases of the supratentorial extradural hematomas secondary to the posterior fossa craniectomy.
The site of the hematoma was far from the operative field and two cases showed acute course and three were rather mild. The symptoms of this complication were the unsuspected sensorium disturbance, anisocoria and the non-functioning ventricular drainage. Two cases died of this complication and two were severely disabled 6).
Multiple Supratentorial Epidural Hematomas
Tyagi et al., from Bangalore published Multiple Remote Sequential Supratentorial Epidural Hematomas 7).
Wolfsberger et al., from Vienna published a 31-year-old female who presented with a history of chronic hydrocephalus due to fourth-ventricular plexus papilloma. Following resection of the posterior fossa tumor with intraoperative placement of a ventricular drainage, she consecutively developed four supratentorial epidural haematomas at different locations, all necessitating evacuation. The clinical manifestations ranged from subtle neurological deficits to signs of tentorial herniation; the ultimate outcome was complete recovery. Rapid tapering of CSF pressure after long-standing hydrocephalus and clotting disorders could be implicated as causative factors. They stressed the importance of early postoperative CT scan and optimal management of ventricular pressure and coagulation status to detect and prevent this possibly life-threatening complication 8).