Cerebral microembolization during primary total hip arthroplasty and neuropsychologic outcome: a pilot study.
BACKGROUND
Intraoperative cerebral microembolization occurs in a substantial proportion of patients undergoing THA. Historically, postoperative cognitive dysfunction has been attributed to different factors, including anesthesia, but the influence of the surgery has not been thoroughly examined.


OBJECTIVE
We conducted a prospective, controlled clinical trial to assess intraoperative cerebral microembolization during THA and neuropsychologic outcome.


METHODS
The presence of a patent foramen ovale (PFO) also was investigated, using transcranial Doppler, to determine whether this affected cerebral microembolic incidence and load and whether microemboli occurred as a result of specific surgical activity. Forty-five patients were recruited who underwent THA and neuropsychologic assessment; a battery of tests was administered preoperatively and at 6 weeks and 6 months postoperatively.


RESULTS
Overall, patients showed improvement in total neuropsychologic change scores at both postoperative intervals. The incidence of cerebral microembolization for THA was 23%. The prevalence of PFO was 37%. PFO did not appear to influence microemboli load or incidence. More microemboli were seen during femoral component insertion and impaction.


CONCLUSIONS
Intraoperative cerebral microembolization occurs in a substantial proportion of patients during THA recorded by transcranial Doppler. The microemboli load is low and is not influenced by the presence of PFO. Certain surgical activities seem responsible for greater cerebral microemboli generation. However, neuropsychologic outcome was not affected postoperatively by microemboli or other operative or patient variables.
Department of Trauma & Orthopaedics, University College London Hospitals Trust, Flat 3, 39 Priory Terrace, NW6 4DG London, UK. rp@rahulpatel.net
Rahul V
RV
Patel
Jan
J
Stygall
Jane
J
Harrington
Stanton P
SP
Newman
Fares S
FS
Haddad
D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D015207:Osteoarthritis, Hip / Q000601:surgery*; D010865:Pilot Projects; D015995:Prevalence; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial