An unusual fatal complication of low basilar trunk aneurysm surgery:: Isolated prepontine tension pneumocephalus

OBJECTIVE A case of postoperative tension pneumocephalus after low basilar trunk aneurysm clipping is presented. To our knowledge, this is the first case of isolated prepontine tension pneumocephalus. BACKGROUND A 63-year-old woman was admitted for repair of a basilar aneurysm that had caused a subarachnoid hemorrhage, She was cooperative and partially oriented. According to Hunt & Hess classification, she was considered Grade III. METHOD The aneurysm was clipped, using a right lateral suboccipital craniectomy with the patient in the sitting position. In the early postoperative period, she had no new neurological deficit. However, 2 hours later the patient became lethargic and unresponsive to verbal commands. Emergency CT scan revealed an isolated prepontine tension pneumocephalus with prominent posterior displacement of the pens. She was immediately taken back to surgery. Upon incision of the dura mater, air could be heard escaping under pressure from the posterior fossa cavity. The clip was in its proper position and all arteries were patent. Spontaneous respiration and pupil reflexes returned soon after surgery, but she remained unconscious and died 3 days later. CONCLUSION We believe that this death was directly attributable to the tension pneumocephalus and the distortion of the pens. Postoperative prepontine tension pneumocephalus, although this is an extremely rare condition, should be considered if a patient deteriorates after basilar aneurysm surgery in the sitting position. (C) 1999 by Elsevier Science Inc.