Background: Cerebral emboli may be detected by transcranial Doppler (TCD) in patients undergoing hip arthroplasty. Venous – arterial circulation shunts (v-aCS), cerebral embolism and postoperative organ dysfunction were investigated in elective hip arthroplasty.
Methods: TCD was used to identify v-aCS in (i) elective hip arthroplasty (n=45), (ii) abdominal aortic aneurysm surgery (AAA) (n=20) and (iii) transurethral resection of prostate (TURP) (n=10). A v-aCS was diagnosed when 1 or more microbubbles were detected in the middle cerebral artery by TCD following intravenous injection of a microbubble emulsion. TCD was also used to monitor for intraoperative cerebral emboli (ICE). Cognitive function was measured by a battery of computerised tests before and 5 days after surgery. Troponin T, AST, ALP, Bilirubin, Creatinine, Urea and Creatinine clearance were measured pre-operatively and 24 and 48 hours post-operatively.
Results: Cerebral embolism occurred in 26 of 45 patients during hip arthroplasty (median 4, range 1 – 368) but not during AAA or TURP surgery. Cerebral embolism only occurred in patients with a v-aCS (p<
0.001) and was strongly associated with the size of the v-aCS (rs=0.8, p<
0.001). The number of ICE had no influence on Troponin T, renal function, liver function or cognitive function.
Conclusion: Cerebral embolism is common in patients with a v-aCS during hip arthroplasty. There was no evidence of cerebral or multi-organ damage due to paradoxical embolism.