title: Current expectations of the arterial switch operation in a small volume center: a 20-year, single-center experience.
abstract: BACKGROUND
  We reviewed our 20-year experience with arterial switch operation (ASO) for transposition of the great arteries (TGA) or double outlet right ventricle with subpulmonary ventricular septal defect (Taussig-Bing anomaly) to assess the early and long-term outcomes.
  
  
  METHODS
  Between January 1995 and December 2014, 139 consecutive patients who underwent ASO for TGA or Taussig-Bing anomaly were included in this retrospective study. The median age at the operation was 9 (0-485) days, and 97 patients (70 %) underwent ASO less than 2 weeks. The median weight was 3.3 (2.1-10.3) kg. The patients were divided into three groups; simple TGA (n = 78) included patients with TGA with intact ventricular septum, complex TGA (n = 46) included those who had TGA with ventricular septal defect or other anomalies, and Taussig-Bing anomaly (n = 15). Median follow-up duration was 72.5 (0.4-230) months.
  
  
  RESULTS
  There were 3(2.2 %) in-hospital deaths. One patient (0.7 %) underwent early reoperation due to coronary insufficiency. Late deaths occurred in 3 (2.2 %) of 136 survivors. The Kaplan-Meier's survival rate was 97.6 ± 1.4 % at 15 years. Twenty-three patients (16.9 %) required 26 reintervention. The freedom from reintervention rates were 82.5 ± 3.7 % at 5 years and 75.8 ± 4.7 % at 10 years, respectively. Median interval between ASO and first reintervention was 22.8 (6.4-89.2) months. The multivariate analysis showed that diagnosis of Taussig-Bing anomaly (hazard ratio, 7.09; P < 0.001) and side by side great artery relationship (hazard ratio, 7.98; P = 0.001) were independent risk factors for reoperation. Five patients (3.9 %) had developed at least moderate neo-aortic regurgitation during the follow-up and one patient underwent reoperation mainly for neo-aortic regurgitation. By multivariate analysis, Taussig-Bing anomaly was the risk factor for at least moderate neo-aortic regurgitation (P = 0.035).
  
  
  CONCLUSIONS
  ASO can be performed with a low risk of early mortality and satisfactory long-term outcomes even in a small volume center. Close long-term surveillance is mandatory to detect structural or hemodynamic changes.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Kangnam-gu, Seoul, 135-710, Korea. mdshmsh@naver.com.
authors.forename: Man-shik
authors.initials: MS
authors.lastname: Shim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Kangnam-gu, Seoul, 135-710, Korea. tgjunsmc@gmail.com.
authors.forename: Tae-Gook
authors.initials: TG
authors.lastname: Jun
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Kangnam-gu, Seoul, 135-710, Korea. jh1.yang@samsung.com.
authors.forename: Ji-Hyuk
authors.initials: JH
authors.lastname: Yang
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Kangnam-gu, Seoul, 135-710, Korea. pw.park@samsung.com.
authors.forename: Pyo Won
authors.initials: PW
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. is04.kang@samsung.com.
authors.forename: I Seok
authors.initials: IS
authors.lastname: Kang
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. herz.huh@samsung.com.
authors.forename: June
authors.initials: J
authors.lastname: Huh
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. amyjys.song@samsung.com.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Song
mesh_terms: D001022:Aortic Valve Insufficiency / Q000209:etiology / Q000601:surgery; D000069278:Arterial Switch Operation / Q000009:adverse effects; D004310:Double Outlet Right Ventricle / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006345:Heart Septal Defects, Ventricular / Q000401:mortality / Q000601:surgery*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014188:Transposition of Great Vessels / Q000401:mortality / Q000601:surgery*; D016896:Treatment Outcome