Microdialysis: intraoperative and posttraumatic applications in neurosurgery

Microdialysis offers a unique opportunity to study the extracellular human brain environment. Our aim was to improve the ability to detect neuronal injury in patients undergoing complicated neurovascular procedures and to detect secondary brain lesions after severe head injury with the use of in vivo microdialytic monitoring. We employed intraoperative microdialysis monitoring in patients with a variety of neurovascular procedures including high-flow and low-flow bypass surgery and aneurysm clipping. In the second group there were patients after severe brain injury where in vivo microdialysis was performed as a bedside monitoring in the intensive care unit. In this review we present our results for these various groups of patients, in which a variety of neurochemical parameters which are known to change in ischemia were studied. The advantages and disadvantages of the technique are discussed. Our results show that microdialysis is a useful tool for detecting ischemic changes intraoperatively and in severe head trauma. However, further studies are needed to get more data and to better refine the online microdialysis technique before we can recommend it for routine clinical use.