title: Control of emboli in patients with recurrent or crescendo transient ischaemic attacks using preoperative transcranial Doppler-directed Dextran therapy.
abstract: BACKGROUND
  Transcranial Doppler (TCD)-directed Dextran 40 treatment after carotid endarterectomy reduces the rate of early postoperative thrombosis. This study assessed the efficacy of intravenous Dextran 40 at controlling symptoms and emboli before elective carotid endarterectomy in patients with recurrent or crescendo transient ischaemic attacks (TIAs).
  
  
  METHODS
  In a prospective study, patients with more than 70 per cent internal carotid artery stenosis who had two or more symptomatic episodes within 30 days and TCD-detected microemboli were studied. Dextran 40 was commenced at 20 ml/h and TCD was repeated to reassess the rate of embolization. The infusion was increased in 20-ml/h increments until symptoms and emboli were controlled. The patient then had carotid surgery on the next elective list.
  
  
  RESULTS
  Nineteen patients with internal carotid stenosis greater than 70 per cent, recurrent symptoms and TCD-detected emboli were studied. All patients had symptoms and emboli controlled with Dextran 40. One patient with both unstable angina (awaiting urgent operation) and crescendo TIAs died from a myocardial infarct before undergoing operation. Of the 18 patients who had an operation, one suffered a non-disabling stroke on the third postoperative day.
  
  
  CONCLUSIONS
  TCD-directed Dextran 40 offers a safe approach to high-risk patients before elective carotid endarterectomy, and warrants further study.
authors.affiliation: Coventry and Warwickshire County Vascular Unit, Coventry University Hospital, Clifford Bridge Road, Walsgrave, Coventry CV2 2DX, UK.
authors.forename: N S
authors.initials: NS
authors.lastname: Lennard
authors.forename: C
authors.initials: C
authors.lastname: Vijayasekar
authors.forename: C
authors.initials: C
authors.lastname: Tiivas
authors.forename: C W M
authors.initials: CW
authors.lastname: Chan
authors.forename: D J
authors.initials: DJ
authors.lastname: Higman
authors.forename: C H E
authors.initials: CH
authors.lastname: Imray
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D016893:Carotid Stenosis / Q000601:surgery; D003911:Dextrans / Q000008:administration & dosage*; D016894:Endarterectomy, Carotid / Q000379:methods*; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000517:prevention & control*; D002546:Ischemic Attack, Transient / Q000150:complications*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011183:Postoperative Complications / Q000517:prevention & control*; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods; D018084:Ultrasonography, Interventional
chemical_list: D000925:Anticoagulants; D003911:Dextrans