Control of Brain Retraction Pressure Using Epidural Intracranial Pressure Monitor System in Early Aneurysm Surgery

OBJECTIVE: To prevent retraction induced cerebral contusion during early aneurysm surgery, we propose a simple technical tip using commonly available Spiegelberg(R) epidural intracranial pressure(ICP) monitor system. METHODS: In this study, twenty six cases of early aneurysm clipping were enrolled. Routine pterional approach were performed. The air-pouch end of epidural ICP system was attached to the tip of Yasargil(R) retractor and the other end of connecter jack was plugged in digital converter. At each stage of approach, the value of retraction power was kept a record. Immediate feedback calls were announced in case of over 25mmHg of the values. RESULTS: The average retraction pressure values at each stage were as follows. At the state of initial optic nerve confirmation, it was about 39+/-10.5mmHg. After immediate intentional re-adjust of the retraction power, it reduced to 22.8+/-4.5mmHg. After sufficient suck out of cerebrospinal fluid(CSF), it more reduced to 11.7+/-3.2mmHg. At the stage of juxta-aneurysmal brain retraction, it was about 9.0+/-4.1mmHg. By the aid of this system, no retraction induced contusion or hemorrhage were occurred. CONCLUSION: This data indicate the usefulness of epidural ICP sensor attached brain retractor for real time feedback of retraction power. It may be another safeguard for successful early aneurysm surgery.

Dialysis Disequilibrium Syndrome in Neurosurgical Patient

Neurological symptoms may develope when the blood urea nitrogen is lowered too rapidly by hemodialysis. It is known that these symptoms, known as dialysis disequilibrium are associated with cerebral edema. However, the pathogenesis of brain swelling and neurological deterioration after rapid hemodialysis is controversial. The reverse urea hypothesis suggests that hemodialysis removes urea more slowly from the brain than from the plasma, creating an osmotic gradient that results in cerebral edema. The idiogenic osmole hypothesis proposes that an osmotic gradient between brain and plasma develops during rapid dialysis because of newly formed brain osmoles. Authors report a such case and discuss the possible mechanism and preventive methods.