Intraoperative cerebral arterial embolization during total hip arthroplasty

Background: Fat embolism to the pulmonary circulation is known to occur dur ing total hip arthroplasty, especially during insertion of a cemented femor al component. Fat and air bubbles may enter the systemic circulation via a patent foramen ovale or through pulmonary circulation. Methods: To determine whether microemboli to the brain were occurring durin g total hip arthroplasty, 23 patients underwent transcranial Doppler assess ment of emboli to the middle cerebral artery during total hip arthroplasty. Surgery was performed with the patient in the lateral decubitus position s o that the probe recorded from the nondependent side. Results: Successful recordings were made in 20 patients, in 8 of 20 patient s there were embolic signals, which ranging from 1 to 200. In all eight pat ients, signals were recorded during impaction of a cemented component or af ter relocation of the hip. Only one patient showed evidence of emboli with impaction of the acetabulum component. In two patients there were 150 and 2 00 embolic signals: in both mild respiratory symptoms developed. One patien t became overtly agitated during a flurry of emboli. Conclusion: Cerebral microemboli can occur during total hip arthroplasty. W hether this contributes to changes in postoperative cognitive function is u nknown.