Supplement 1: Reasons for excluding studies during eligibility phase

CAS/CEA performed for non-carotid atherosclerotic disease:

  1. Awano et al2010Intraoperative EC-IC Bypass Blood Flow Assessment WithIndocyanine Green Angiography in Moyamoya and Non-Moyamoya Ischemic Stroke.
  2. Azaki et al1999Common brachiocephalic trunk: strategies for revascularization.
  3. De Paula et al2013Clinical and vascular features of Takayasu arteritis at the time of ischemic stroke.
  4. Fujimura et al2007Temporary neurologic deterioration due to cerebral hyperperfusion after superficial temporal artery-middle cerebral artery anastomosis in patients with adult-onset moyamoya disease.
  5. Fujimura et al2014Genetics and Biomarkers of Moyamoya Disease: Significance of RNF213 as a Susceptibility Gene.
  6. Fugimura et al2015Quantitative analysis of early postoperative cerebral blood flow contributes to the prediction and diagnosis of cerebral hyperperfusion syndrome after revascularization surgery for moyamoya disease.
  7. Greene et al2014Perioperative Management of Carotid Endarterectomy: A Survey of Clinicians’ Backgrounds and Practices.
  8. Hayashi et al2012Incidence and Clinical Features of Symptomatic Cerebral Hyperperfusion Syndrome After Vascular Reconstruction.
  9. Horie et al2014De novo ivy sign indicates postoperative hyperperfusion in moyamoya disease.
  10. Houkin et al2004Pitfalls in cerebral revascularization surgery.
  11. Ishishita et al2014Peer-Review Report: Universal Extracranial-Intracranial Graft Bypass for Large or Giant Internal Carotid Aneurysms: Techniques and Results in 38 Consecutive Patients.
  12. Kaps et al1990Intracranial haemodynamics in patients with spontaneous carotid dissection. Transcranial Doppler ultrasound follow-up studies.
  13. Kim et al2012Clinical research study: Surgical bypass vs endovascular treatment for patients with supra-aortic arterial occlusive disease due to Takayasu arteritis.
  14. Meyer et al1998Physiological steal around AVMs of the brain is not equivalent to cortical ischemia.
  15. Meyers et al2000Cerebral hyperperfusion syndrome after percutaneous transluminal stenting of the craniocervical arteries. Neurosurgery 2000;47:335–343
  16. Qureshi et al2002Intracerebral Hemorrhages Associated With Neurointerventional Procedures Using a Combination of Antithrombotic Agents Including Abciximab
  17. Rodan et al2015Cerebral hyperperfusion and decreased cerebrovascular reactivity correlate with neurologic disease severity in MELAS.
  18. Sugiyama et al2015Reappraisal of Microsurgical Revascularization for Anterior Circulation Ischemia in Patients with Progressive Stroke.
  19. Terada et al2006Hemorrhagic Complications after Endovascular Therapy for Atherosclerotic Intracranial Arterial Stenosis
  20. Teo et al2013Cerebral hyperperfusion syndrome after superficial temporal artery-middle cerebral artery bypass for severe intracranial steno-occlusive disease: a case control study.
  21. Yamagushi et al2010Incidence and predictive factors of cerebral hyperperfusion after extracranial-intracranial bypass for occlusive cerebrovascular diseases.
  22. Wang et al2015Predicting Cerebral Hyperperfusion Syndrome Following Superficial Temporal Artery to Middle Cerebral Artery Bypass based on Intraoperative Perfusion-Weighted Magnetic Resonance Imaging.

Absence of specific ICH/HPS data:

  1. Aralasmak et al2015Hyperperfusion in carotid stenting patients.
  2. Bandyk et al2009Use of intravascular ultrasound as a "Quality Control" technique during carotid stent-angioplasty: are there risks to its use?
  3. Beard et al 2001 Prevention of postoperative wound haematomas and hyperperfusion following carotid endarterctomy
  4. Beliaev et al2011Syndrome of cerebral hyperperfusion after carotid endarterectomy
  5. Benichou et al1996Carotid angioplasty and stenting: will periprocedural transcranial Doppler monitoring be important?
  6. Bergeron et al1996Recurrent carotid disease: will stents be an alternative to surgery?
  7. Cai et al2014Learning curve for intracranial angioplasty and stenting in single center.
  8. Chang et al2009Change in cerebral perfusion after carotid angioplasty with stenting is related to cerebral vasoreactivity: a study using dynamic susceptibility-weighted contrast-enhanced MR imaging and functional MR imaging with a breath-holding paradigm.
  9. Cho et al2014Reperfusion injury on magnetic resonance imaging after carotid revascularization.
  10. Du Mesnil de Rochemont et al2006Diffusion-weighted MR imaging lesions after filter-protected stenting of high-grade symptomatic carotid artery stenoses.
  11. Edwards et al1988Prevention of stroke during carotid endarterectomy.
  12. Fukuda et al2007Prediction of cerebral hyperperfusion after carotid endarterectomy using cerebral blood volume measured by perfusion-weighted MR imaging compared with single-photon emission CT.
  13. Katano et al2014Surgical Treatment for Carotid Stenoses with Highly Calcified Plaques.
  14. Hines et al2011Post-Carotid Endarterectomy Hyperperfusion Syndrome—Is It Predictable by Lack of Cerebral Reserve?
  15. Hirooka et al2008Magnetic resonance imaging in patients with cerebral hyperperfusion and cognitive impairment after carotid endarterectomy.
  16. Hosoda et al2003Prediction of hyperperfusion after carotid endarterectomy by brain SPECT analysis with semiquantitative statistical mapping method.
  17. Iwata et al2011Predictors of hyperperfusion syndrome before and immediately after carotid artery stenting in single-photon emission computed tomography and transcranial color-coded real-time sonography studies.
  18. Iwata et al2014Global oxygen extraction fraction by blood sampling to anticipate cerebral hyperperfusion phenomenon after carotid artery stenting.
  19. Karkos et al2010Thirty-day outcome following carotid artery stenting: a 10-year experience from a single center.
  20. Kawai et al2014Cerebral Blood Flow and Oxygen Metabolism Measurements Using Positron Emission Tomography on the First Day after Carotid Artery Stenting.
  21. Kim et al2013Post-carotid endarterectomy cerebral hyperperfusion syndrome : is it preventable by strict blood pressure control?
  22. Kim et al2013Pulse pressure variation and stroke volume variation to predict fluid responsiveness in patients undergoing carotid endarterectomy.
  23. Komoribayashi et al2006Cerebral hyperperfusion after carotid endarterectomy is associated with preoperative hemodynamic impairment and intraoperative cerebral ischemia.
  24. Kyung et al2013Pulse pressure variation and stroke volume variation to predict fluid responsiveness in patients undergoing carotid endarterectomy.
  25. Leonardi et al2008Carotid Stenting without Angioplasty and without Protection: The Advantages of a Less Invasive Procedure.
  26. Maltezos et al2007Changes in Blood Flow of Anterior and Middle Cerebral Arteries Following Carotid Endarterectomy: A Transcranial Doppler Study.
  27. Matsubara et al2009Analysis of cerebral perfusion and metabolism assessed with positron emission tomography before and after carotid artery stenting.
  28. Murakami et al2010Brain temperature measured by using proton MR spectroscopy predicts cerebral hyperperfusion after carotid endarterectomy.
  29. Ogami et al2011Cerebrospinal fluid enhancement on fluid attenuated inversion recovery images after carotid artery stenting with neuroprotective balloon occlusions: hemodynamic instability and blood-brain barrier disruption.
  30. Ogasawara et al2005Postoperative cerebral hyperperfusion associated with impaired cognitive function in patients undergoing carotid endarterectomy.
  31. Ogasawara et al2008Significance of postoperative crossed cerebellar hypoperfusion in patients with cerebral hyperperfusion following carotid endarterectomy: SPECT study.
  32. Ogasawara et al2009Prediction of cerebral hyperperfusion after carotid endarterectomy using middle cerebral artery signal intensity in preoperative single-slab 3-dimensional time-of-flight magnetic resonance angiography.
  33. Oriel et al1999Intracerebral hemorrhage after carotid endarterectomy: Incidence, contribution to neurologic morbidity, and predictive factors
  34. Paul et al2011Polymorphisms in complement component 3 (C3F) and complement factor H (Y402H) increase the risk of postoperative neurocognitive dysfunction following carotid endarterectomy.
  35. Pennekamp et al2012When to perform transcranial Doppler to predict cerebral hyperperfusion after carotid endarterectomy?
  36. Pennekamp et al2012Prediction of Cerebral Hyperperfusion after Carotid Endarterectomy with Transcranial Doppler.
  37. Pennekamp et al2012Near-Infrared Spectroscopy Can Predict the Onset of Cerebral Hyperperfusion Syndrome after Carotid Endarterectomy.
  38. Reigel et al1987Cerebral hyperperfusion syndrome: A cause of neurologic dysfunction after carotid endarterectomy.
  39. Reith et al1992Spontaneous intracerebral hemorrhage following carotid endarterectomy. Experience of 328 operations from 1983-1988.
  40. Schaafsma et al2002Hyperperfusion Syndrome Identified by Daily Transcranial Doppler Investigation After Carotid Surgery.
  41. Schroeder et al1987Cerebral hyperperfusion following carotid endarterectomy
  42. Schwartz et al2002Hyperperfusion encephalopathies: hypertensive encephalopathy and related conditions.
  43. Shang et al2011Cerebral monitoring during carotid endarterectomy using near-infrared diffuse optical spectroscopies and electroencephalogram.
  44. Soong et al1996The generation of byproducts of lipid peroxidation following carotid endarterectomy.
  45. Suga et al2007Preoperative cerebral hemodynamic impairment and reactive oxygen species produced during carotid endarterectomy correlate with development of postoperative cerebral hyperperfusion.
  46. Szarmach et al2011Evaluation of changes in the parameters of brain tissue perfusion in multi-slice computed tomography in patients after carotid artery stenting.
  47. Széplaki et al2008Early complement activation follows eversion carotid endarterectomy and correlates with the time of clamping of the carotid artery.
  48. Tehindraza-narivelo et al1992Headache following carotid endarterectomy: a prospective study.
  49. Terada et al2010Endovascular recanalization of the completely occluded internal carotid artery using a flow reversal system at the subacute to chronic stage.
  50. Tran Dinh et al1997Cerebral postischemic hyperperfusion assessed by Xenon-133 SPECT.
  51. Tseng et al2009Prediction of cerebral hyperperfusion syndrome after carotid stenting: a cerebral perfusion computed tomography study.
  52. Van Putten et al2004A brain symmetry index (BSI) for online EEG monitoring in carotid endarterectomy.
  53. Vitek et al2002Carotid stenting with distal balloon protection: technical considerations (preliminary experience).
  54. Wada et al2015Evaluation of changes of intracranial blood flow after carotid artery stenting using digital subtraction angiography flow assessment.
  55. Wang et al2015Decreased 13N‑labeled ammonia uptake in the ipsilateral and contralateral hemispheres following carotid endarterectomy.
  56. Wylie et al1964Intracranial Hemorrhage Following Surgical Revascularization for Treatment of Acute Strokes
  57. Yamashita et al2005Measurement of cerebral reserve capacity using acetazolamide loading xenon CT CBF before carotid endarterectomy.
  58. Ziaja et al2014Neurological symptoms associated with cerebral hyperperfusion syndrome after CEA and CAS--one centre study.

Duplication of the population included in another studies:

  1. Hingorani et al2002Causes of early post carotid endartectomy stroke in a recent series: the increasing importance of hyperperfusion syndrome.

(Population included in Ascher et al, 2003)

  1. Ogasawara et al2003Transcranial regional cerebral oxygen saturation monitoring during carotid endarterectomy as a predictor of postoperative hyperperfusion.

(Population included in Ogasawara et al 2003)

Highly selected populations or experimental studies:

  1. Fujimoto et al2004Diagnostic impact of transcranial color-coded real-time sonography with echo contrast agents for hyperperfusion syndrome after carotid endarterectomy.
  2. George et al1993Cerebral hyperperfusion syndrome: an etiology of seizures following carotid endarterectomy.
  3. Kawamata et al2009Postcarotid endarterectomy cerebral hyperperfusion can be prevented by minimizing intraoperative cerebral ischemia and strict postoperative blood pressure control under continuous sedation.
  4. Kieburtz et al1990Seizures following carotid endarterectomy.
  5. Muller et al1999Cerebrovascular resistance and blood flow velocity changes after carotid endarterectomy.
  6. Nael et al2013Periprocedural arterial spin labeling and dynamic susceptibility contrast perfusion in detection of cerebral blood flow in patients with acute ischemic syndrome.
  7. Ogasawara et al2004Pretreatment with the free radical scavenger edaravone prevents cerebral hyperperfusion after carotid endarterectomy.
  8. Rugonfalvi et al2011High rate of early restenosis after carotid eversion endarterectomy in homozygous carriers of the normal mannose-binding lectin genotype.
  9. Sbarigia et al1993Post-carotid endarterectomy hyperperfusion syndrome: preliminary observations for identifying at risk patients by transcranial Doppler sonography and the acetazolamide test.
  10. Seungnam et al2015Emergency carotid artery stenting in patients with acute ischemic stroke due to occlusion or stenosis of the proximal internal carotid artery: a single-center experience.
  11. Seungnam et al2013Carotid artery stenting in patients with near occlusion: Asingle-center experience and comparison with recent studies
  12. Son et al2015Emergency carotid artery stenting in patients with acute ischemic stroke due to occlusion or stenosis of the proximal internal carotid artery: a single-center experience.
  13. Ushida et al2015Experience of Staged Angioplasty to Avoid Hyperperfusion Syndrome for Carotid Artery Stenosis.
  14. Walsh et al2010Remote ischemic preconditioning for cerebral and cardiac protection during carotid endarterectomy: results from a pilot randomized clinical trial.
  15. Yoshida et al2015Post-carotid endarterectomy changes in cerebral glucose metabolism on (18)F-fluorodeoxyglucose positron emission tomography associated with postoperative improvement or impairment in cognitive function.
  16. Yoshimura et al2009Staged angioplasty for carotid artery stenosis to prevent postoperative hyperperfusion.

Administrative data:

1.McDonald2011Intracranial Hemorrhage Is Much More Common After Carotid Stenting Than After Endarterectomy. Evidence from the National Inpatient Sample.