title: Multimodal fetal transesophageal echocardiography for fetal cardiac intervention in sheep.
abstract: BACKGROUND
  The overall performance of available mechanical intravascular ultrasound catheters for fetal transesophageal echocardiography during fetoscopic fetal cardiac interventions in sheep has been limited by radioelectronic interference, low system frame rates, and low acoustic outputs. Therefore, a more reliable device is desired for human fetoscopic surgical procedures.
  
  
  RESULTS
  We assessed the potential of a newly available 10-French phased-array intravascular ultrasound catheter for multimodal fetal transesophageal echocardiography in 5 fetal sheep between 78 and 98 days of gestation (term, 145 to 150 d). The intravascular ultrasound catheter was easily inserted through the mouth into the esophagus in all 5 sheep fetuses (mean weight, 600 g), and it permitted high-quality 2D imaging of the fetal heart in vertical imaging planes that were validated by MRI. Color Doppler and pulsed Doppler imaging permitted clear assessment of fetal cardiovascular flows and recording of velocity-time integral tracings of the fetal heart and great vessels. The vertical imaging planes were particularly useful to demonstrate interventional material inside the fetal heart and great vessels.
  
  
  CONCLUSIONS
  Our early experience with the phased-array intravascular ultrasound catheter indicates that multimodal fetal transesophageal echocardiography has now become possible in these smallest of patients.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Prenatal Medicine, University of Lübeck, Lübeck, Germany. thokohl@t-online.de
authors.forename: T
authors.initials: T
authors.lastname: Kohl
authors.forename: M
authors.initials: M
authors.lastname: Westphal
authors.forename: D
authors.initials: D
authors.lastname: Strümper
authors.forename: S
authors.initials: S
authors.lastname: Achenbach
authors.forename: S
authors.initials: S
authors.lastname: Halimeh
authors.forename: P
authors.initials: P
authors.lastname: Petry
authors.forename: S
authors.initials: S
authors.lastname: Aryee
authors.forename: T
authors.initials: T
authors.lastname: Buller
authors.forename: R
authors.initials: R
authors.lastname: Aleksiene
authors.forename: B
authors.initials: B
authors.lastname: Asfour
authors.forename: R
authors.initials: R
authors.lastname: Witteler
authors.forename: J
authors.initials: J
authors.lastname: Vogt
authors.forename: H
authors.initials: H
authors.lastname: Van Aken
authors.forename: H H
authors.initials: HH
authors.lastname: Scheld
mesh_terms: D000818:Animals; D002404:Catheterization / Q000295:instrumentation*; D015150:Echocardiography, Doppler / Q000295:instrumentation / Q000379:methods; D017548:Echocardiography, Transesophageal / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D005333:Fetus; D008279:Magnetic Resonance Imaging; D011247:Pregnancy; D015203:Reproducibility of Results; D018615:Ultrasonography, Doppler, Color / Q000295:instrumentation / Q000379:methods; D016216:Ultrasonography, Prenatal / Q000295:instrumentation / Q000379:methods*