title: Extracranial carotid arteriopathy in stroke-free children with sickle cell anemia: detection by submandibular Doppler sonography.
abstract: BACKGROUND
  Cerebral vasculopathy is a serious complication of sickle cell anemia. Overt strokes are largely due to intracranial arteriopathy, detected by routine transcranial Doppler and largely prevented through chronic transfusions. As extracranial internal carotid artery arteriopathy was considered rare, it has not been routinely assessed in sickle cell anemia. Recent cases of overt strokes associated with stenosis/occlusion of the extracranial portion of the internal carotid artery prompted us to include extracranial internal carotid artery assessment to our transcranial Doppler sonography protocol.
  
  
  OBJECTIVE
  The aim of the study was to perform a cross-sectional study in children with sickle cell anemia to evaluate Doppler flow patterns of the extracranial internal carotid arteries and to assess potential associated factors.
  
  
  METHODS
  Between June 2011 and April 2012, 435 consecutive stroke-free children with sickle cell anemia (200/235 M/F, median age: 7.9 years) were assessed for extracranial internal carotid artery using a 2-MHz transcranial Doppler sonography probe via a submandibular window during routine transcranial Doppler sonography visits. The course of both extracranial internal carotid artery was assessed by color Doppler mapping, and the highest flow velocity was recorded after insonation of the entire length of the artery and analyzed. Intra- and extracranial MR angiographies were available in 104/435 subjects for comparison.
  
  
  RESULTS
  Mean (SD) extracranial internal carotid artery time-averaged mean of maximum velocity was 96 (40) cm/s. Extracranial internal carotid artery tortuosities were echo-detected in 25% cases and were more frequent in boys (33% vs.18%; P < 0.001). Velocity ≥160 cm/s in at least one extracranial internal carotid artery was found in 45 out of 435 patients with sickle cell anemia (10.3%) and was highly predictive of MR angiography stenosis. Simultaneous abnormal intracranial velocity (≥200 cm/s) was recorded in 5/45 patients, while 40 patients had isolated extracranial internal carotid artery velocity ≥160 cm/s. Low hemoglobin (odds ratio: 1.9/g/dL, 95% confidence interval (CI): 1.3-2.9; P = 0.001) and tortuosities (odds ratio: 19.2, 95% CI: 7.1-52.6; P < 0.001) were significant and independent associated factors for isolated extracranial internal carotid artery velocities ≥160 cm/s.
  
  
  CONCLUSIONS
  Adding extracranial internal carotid artery evaluation via the submandibular window to transcranial Doppler sonograpy allowed us to detect 10.3% patients at risk for extracranial internal carotid arteriopathy. Further studies are needed to evaluate the prognosis of these anomalies.
authors.affiliation: Department of Pediatric Imaging, University Paris VII, Assistance-Publique-Hôpitaux de Paris, Hospital Robert Debré, Paris, France, suzanne.verlhac@chicreteil.fr.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Verlhac
authors.forename: Stéphane
authors.initials: S
authors.lastname: Balandra
authors.forename: Isabelle
authors.initials: I
authors.lastname: Cussenot
authors.forename: Florence
authors.initials: F
authors.lastname: Kasbi
authors.forename: Manuela
authors.initials: M
authors.lastname: Vasile
authors.forename: Ahmed
authors.initials: A
authors.lastname: Kheniche
authors.forename: Monique
authors.initials: M
authors.lastname: Elmaleh-Bergès
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Ithier
authors.forename: Malika
authors.initials: M
authors.lastname: Benkerrou
authors.forename: Françoise
authors.initials: F
authors.lastname: Bernaudin
authors.forename: Guy
authors.initials: G
authors.lastname: Sebag
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000000981:diagnostic imaging / Q000209:etiology; D013363:Submandibular Gland / Q000000981:diagnostic imaging*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*