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Cerebrovascular disease
Safety of transcranial Doppler ‘bubble study’ for identification of right to left shunts: an international multicentre study
  1. Georgios Tsivgoulis1,
  2. Elefterios Stamboulis2,
  3. Vijay K Sharma3,
  4. Ioannis Heliopoulos1,
  5. Konstantinos Voumvourakis2,
  6. Hock Luen Teoh3,
  7. Konstantinos Vadikolias1,
  8. Nikos Triantafyllou4,
  9. Bernard P L Chan3,
  10. Spyros N Vasdekis5,
  11. Charitomeni Piperidou1
  1. 1Department of Neurology, Democritus University of Thrace, School of Medicine, Alexandroupolis, Greece
  2. 2Second Department of Neurology, University of Athens, School of Medicine, Attikon Hospital, Athens, Greece
  3. 3Department of Neurology, National University Hospital, Singapore, Singapore
  4. 4First Department of Neurology, University of Athens, School of Medicine, Eginition Hospital, Athens, Greece
  5. 5Third Surgical Department, Vascular Unit, Attikon Teaching Hospital, University of Athens, Athens, Greece
  1. Correspondence to Dr G Tsivgoulis, Kapodistriou 3, Nea Chili, Alexandroupolis, 68100, Greece; tsivgoulisgiorg{at}


Background and purpose A recent retrospective study using an online list service established by the American Academy of Neurology has suggested that ischaemic cerebrovascular events may occur in patients who undergo ‘bubble studies’ (BS) with either transcranial Doppler (TCD) or transoesophageal echocardiography (TOE). The safety of TCD-BS for right to left shunt (RLS) identification was evaluated prospectively in an international multicentre study.

Methods Consecutive patients with cerebral ischaemia (ischaemic stroke or transient ischaemic attack (TIA)) were screened for potential ischaemic cerebrovascular events following injection of microbubbles during TCD-BS for identification of RLS at three tertiary care stroke centres. TCD-BS was performed according to the standardised International Consensus Protocol. TOE-BS was performed in selected cases for confirmation of TCD-BS.

Results 508 patients hospitalised with acute cerebral ischaemia (mean age 46±12 years, 59% men; 63% ischaemic stroke, 37% TIA) were investigated with TCD-BS within 1 week of ictus. RLS was identified in 151 cases (30%). TOE-BS was performed in 101 out of 151 patients with RLS identified on TCD-BS (67%). It was positive in 99 patients (98%). The rate of ischaemic cerebrovascular complications during or after TCD-BS was 0% (95% CI by the adjusted Wald method: 0–0.6%). Structural cardiac abnormalities were identified in 38 patients, including atrial septal aneurysm (n=23), tetralogy of Fallot (n=1), intracardiac thrombus (n=2), ventricular septal defect (n=3) and atrial myxoma (n=1).

Conclusion TCD-BS is a safe screening test for identification of RLS, independent of the presence of cardiac structural abnormalities.

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  • Competing interests None.

  • Ethics approval The ethics committees of all three institutions involved in the study approved the study protocol.

  • Provenance and peer review Not commissioned; externally peer reviewed.