Evaluation of an intraoperative algorithm based on near-infrared refracted spectroscopy monitoring, in the intraoperative decision for shunt placement, in patients undergoing carotid endarterectomy.

Background: We evaluated whether the use of an intraoperative algorithm based on cerebral oximetry with near-infrared refracted spectroscopy (NIRS) monitoring, could aid in the intraoperative decision for shunt placement, in patients undergoing carotid endarterectomy (CEA). Methods: In this prospective, randomized, controlled study were included 253 patients who underwent CEA under general anesthesia. They were randomly allocated in Group A (n = 83) using NIRS monitoring and the suggested algorithm, Group B (n = 84) using NIRS monitoring without the algorithm and Group C (n = 86) who served as controls. Shunt placement criterion for Group A and B was 20% drop in ipsilateral regional saturation from the baseline value recorded before surgery. Primary endpoint of the study was to evaluate the use of the intraoperative algorithm based on NIRS monitoring, in the intraoperative decision for shunt placement, in patients undergoing carotid endarterectomy. Additionally, we examined whether this might affect the rate of postoperative neurologic deficits. Results: When compared with Group A, Group B and Group C had 3.7 times (99% c.i 1.59.5) and 70.6 times (99% c.i. 15-724.3) respectively, greater likelihood of having a shunt placed. When compared with Group B, Group C had 19.4 times (99% c.i. 4.3-191.2) greater likelihood of having a shunt placed. Regarding the rate of postoperative neurologic deficits no significant difference was found between the three groups. Conclusions: The use of a specific algorithm based on NIRS monitoring, in patients undergoing CEA, may aid in the intraoperative decision for shunt placement. * Consultant Anesthetist, «G Gennimatas» General Hospital of Athens, Greece. ** Associate Professor of Anesthesia, Department of Anesthesia, Democritus University of Thrace Medical School, Greece. *** Professor of Vascular Surgery, Medical School, Democritus University of Thrace, Greece. **** Assistant Professor of Anesthesia, Medical School, Democritus University of Thrace, Greece. ***** Associate Professor, Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, Texas, USA. ****** Consultant Vascular Surgeon, Department of Vascular Surgery, «G Gennimatas» General Hospital of Athens, Greece. ******* Associate Professor of Anesthesia, Head of Department of Anesthesia, «G Gennimatas» General Hospital of Athens, Greece. Corresponding Author: Vassilios K Dimitriou, Associate Professor of Anesthesia, Head of Department of Anesthesia, «G Gennimatas» General Hospital of Athens, 154 Mesogion Avenue, 11527 Athens, Greece. Fax: +302132032212. E-mail address: vaskdimi@otenet.gr 368 I. D. ZOGOGIANNIS ET AL.