title: Paradoxical cerebral embolisation. An explanation for fat embolism syndrome.
abstract: Fat embolism occurs following fractures of a long bone or arthroplasty. We investigated whether paradoxical embolisation through a venous-to-arterial circulation shunt (v-a) could lead to cerebral embolisation during elective hip or knee arthroplasty. Transcranial Doppler ultrasound (TCD), following the intravenous injection of microbubble contrast, identified the presence of a shunt in 41 patients undergoing hip (n = 20) or knee (n = 21) arthroplasty. Intra-operative cerebral embolism was detected during continuous TCD monitoring. Of the 41 patients, 34 had a v-a shunt of whom 18 had an embolism and embolism only occurred in patients with a shunt (p = 0.012). Spontaneous and larger shunts were associated with a greater number of emboli (rs = 0.67 and rs = 0.71 respectively, p < 0.01). Observations in two patients with large spontaneous shunts revealed 368 and 203 emboli and unexplained post-operative confusion and pancreatitis. Paradoxical cerebral embolisation only occurred in patients with a shunt and may explain both postoperative confusion and fat embolism syndrome following surgery.
authors.affiliation: Academic Surgery Unit, South Manchester University Hospital, Southmoor Road, Manchester M23 9LT, England, UK.
authors.forename: G
authors.initials: G
authors.lastname: Riding
authors.forename: K
authors.initials: K
authors.lastname: Daly
authors.forename: S
authors.initials: S
authors.lastname: Hutchinson
authors.forename: S
authors.initials: S
authors.lastname: Rao
authors.forename: M
authors.initials: M
authors.lastname: Lovell
authors.forename: C
authors.initials: C
authors.lastname: McCollum
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D004620:Embolism, Fat / Q000209:etiology*; D019320:Embolism, Paradoxical / Q000209:etiology*; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications* / Q000000981:diagnostic imaging; D020766:Intracranial Embolism / Q000209:etiology*; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D013577:Syndrome; D017585:Ultrasonography, Doppler, Transcranial