title: Right ventricular outflow tract obstruction after arterial switch operation for the Taussig-Bing heart.
abstract: OBJECTIVE
  Incidence of right ventricular outflow tract obstruction (RVOTO) may be suspected to be higher after arterial switch operation (ASO) for Taussig-Bing heart than after ASO for transposition of the great arteries (TGA), as Taussig-Bing anomaly is frequently associated with aortic arch obstruction and subvalvular aortic stenosis. We evaluated the risk to develop RVOTO after ASO for Taussig-Bing heart.
  
  
  METHODS
  The 34 Taussig-Bing cases who underwent ASO from 1984 to 2005 were reviewed. RVOTO was defined as peak echo-gradient >or=30 mmHg across right ventricular outflow tract. Kaplan-Meier method was used to estimate time-related events.
  
  
  RESULTS
  Subaortic stenosis was resected in 25 patients, 20 of whom (80%: 20/25) were discharged from hospital free from RVOTO. There was one early death: 2.9% mortality. Three patients died late. Actuarial survival was 85.1%+/-7.0% from 54 month onwards. Eleven survivors (36.7%: 11/30) experienced postoperative RVOTO. Obstruction was seen in 82% (9/11) of cases at subvalvular and/or valvular level. Surgery (n=4) or percutaneous intervention (n=2) was required in six patients. Patients discharged from hospital with RVOTO (n=8) were more likely to undergo reintervention for RVOTO (p=0.026). Freedom from reintervention for RVOTO decreased rapidly in the first two years to 86.5+/-6.3%, slowly thereafter (80.4+/-8.4% at year 7) and stabilized at 70.3+/-11.9% from year 11 on. Risk for RVOTO occurrence was 23.5+/-7.3% early after repair and progressively increased to level out at 53.6+/-11% at year 11. Patients who underwent subaortic resection were more likely (p=0.023) to be free from RVOTO occurrence or development. In the period under review, for patients who underwent ASO for simple (n=355) and complex (n=92) TGA, reoperation rate for neopulmonary stenosis was 0.3% (1/355) and 5.4% (5/92), respectively, to be compared to 11.8% (4/34) RVOTO rate of reoperation for Taussig-Bing heart in this study.
  
  
  CONCLUSIONS
  Postoperative right-sided obstruction occurs more frequently after ASO repair of Taussig-Bing heart than after TGA arterial switching, leading to higher reintervention rate. Resection of the commonly associated subaortic stenosis often prevents RVOTO development.
authors.affiliation: Department of Pediatric Thoracic and Cardiovascular Surgery, Congenital Cardiac Center (Deutsches Kinderherzzentrum), Sankt Augustin, Germany. n.sinzobahamvya@asklepios.com
authors.forename: Nicodème
authors.initials: N
authors.lastname: Sinzobahamvya
authors.forename: Hedwig C
authors.initials: HC
authors.lastname: Blaschczok
authors.forename: Boulos
authors.initials: B
authors.lastname: Asfour
authors.forename: Claudia
authors.initials: C
authors.lastname: Arenz
authors.forename: Marka J
authors.initials: MJ
authors.lastname: Jussli
authors.forename: Ehrenfried
authors.initials: E
authors.lastname: Schindler
authors.forename: Joachim
authors.initials: J
authors.lastname: Photiadis
authors.forename: Andreas E
authors.initials: AE
authors.lastname: Urban
mesh_terms: D001020:Aortic Stenosis, Subvalvular / Q000150:complications / Q000401:mortality / Q000601:surgery; D006348:Cardiac Surgical Procedures / Q000379:methods; D004310:Double Outlet Right Ventricle / Q000150:complications / Q000401:mortality / Q000601:surgery*; D015150:Echocardiography, Doppler; D006352:Heart Ventricles / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D011183:Postoperative Complications / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D012086:Reoperation; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology