title: Factors affecting technical success of fetal aortic valve dilation.
abstract: OBJECTIVE
  We have reported previously that valve dilation enhances growth of cardiac structures and may prevent hypoplastic left heart syndrome (HLHS) in fetuses with critical aortic stenosis. We aimed to investigate maternal/fetal factors which may affect the technical success of fetal valvuloplasty, and to describe perinatal complications of the procedure.
  
  
  METHODS
  This was a descriptive series of 22 fetuses diagnosed with critical aortic stenosis developing into HLHS which underwent intervention by valvuloplasty. Initially this was attempted using a percutaneous approach; reassessment after our first five attempts, only one of which was successful, led to the introduction of the option of laparotomy. Technical success was defined as balloon inflation across the aortic annulus and a broader jet through the aortic valve as assessed by Doppler. Data collected included body mass index, demographic variables, ultrasound findings and postprocedure interventions.
  
  
  RESULTS
  Technical success increased significantly if maternal laparotomy was an option (83.3% vs. 20.0%, P = 0.017). Laparotomy was performed in 66.6% (12/18) of cases. There was a learning curve that showed an increase in success rate and decrease in need for laparotomy over the 3-year study period. Neither the need for laparotomy nor the chances of technical success were predictable by gestational age, body mass index or placental location. Tocolysis was limited to perioperative prophylaxis; one woman experienced wound infection and fluid overload. Postoperatively, three fetuses died and two delivered prematurely, 2 and 7 weeks after intervention.
  
  
  CONCLUSIONS
  Fetal aortic valvuloplasty can be performed with technical success, with low fetal loss rate and few maternal complications. While the need for laparotomy cannot be predicted, having it available as an option improves the technical success rate.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Boston, MA 02115, USA. lwilkinshaug@partners.org
authors.forename: L E
authors.initials: LE
authors.lastname: Wilkins-Haug
authors.forename: W
authors.initials: W
authors.lastname: Tworetzky
authors.forename: C B
authors.initials: CB
authors.lastname: Benson
authors.forename: A C
authors.initials: AC
authors.lastname: Marshall
authors.forename: R W
authors.initials: RW
authors.lastname: Jennings
authors.forename: J E
authors.initials: JE
authors.lastname: Lock
mesh_terms: D000328:Adult; D001021:Aortic Valve; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D002404:Catheterization / Q000379:methods*; D016009:Chi-Square Distribution; D015150:Echocardiography, Doppler; D005260:Female; D005865:Gestational Age; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000517:prevention & control; D011247:Pregnancy; D016896:Treatment Outcome; D016216:Ultrasonography, Prenatal