title: Outcomes of Subaortic Obstruction Resection in Children.
abstract: BACKGROUND
  Studies of long-term outcomes of discrete subaortic stenosis are rare. Therefore, we reviewed the long-term outcomes of fibromuscular resection in children with subaortic stenosis over 26 years from a single institution.
  
  
  METHODS
  We conducted a retrospective review of all children (n=72) who underwent resection of subaortic obstruction for discrete subaortic stenosis between 1989 and 2015.
  
  
  RESULTS
  Median age at surgery was 5.0 years (2.7-7.6 years). There were no operative deaths but three late deaths (4.2%, 3/72). Overall Kaplan-Meier survival at 10 years was 93.0 ± 3.9% (95% CI: 79.6, 97.7). Peak instantaneous left ventricular outflow tract Doppler gradient decreased from 74.2±36.7mmHg (16.0-242.0mmHg) preoperatively to 12.8±7.4mmHg (2.6-36.0mmHg) postoperatively (p<0.001). Mean left ventricular outflow tract Doppler gradient decreased from 42.4±17.2mmHg (12.0-98.0) preoperatively to 7.5±2.7mmHg (1.4-19.3mmHg) postoperatively (p<0.001). However, over the mean follow-up period of 7.8±6.1 years (0.1-25.2 years), 29.0% (20/69) of patients had recurrence and 18.8% (13/69) required reoperation at median time of 4.8 years (3.1-9.1 years) after the initial repair. Freedom from reoperation at 10 years was 71.1±7.1% (95% CI: 54.6, 82.3). Risk factors for reoperation were age less than five years at initial repair (p=0.036) and extension of the membrane to the aortic valve (p=0.001). Aortic insufficiency was present in 54.2% (39/72) of patients preoperatively. Progression of aortic insufficiency occurred in 38.9% (28/72). Involvement of the aortic valve at initial repair was associated with need for subsequent aortic valve repair or replacement (p=0.01).
  
  
  CONCLUSIONS
  Resection of subaortic obstruction is associated with low mortality and morbidity. Recurrence and reoperation rates are high and progression of aortic insufficiency following subaortic resection is common. Therefore, these patients warrant close follow-up into adult life.
authors: Royal Children's Hospital, Melbourne, Vic., Australia; University of Melbourne, Melbourne, Vic., Australia.
authors: Julia S
authors: JS
authors: Donald
authors: Royal Children's Hospital, Melbourne, Vic., Australia; University of Melbourne, Melbourne, Vic., Australia; Murdoch Children's Research Institute, Melbourne, Vic., Australia.
authors: Phillip S
authors: PS
authors: Naimo
authors: Royal Children's Hospital, Melbourne, Vic., Australia; University of Melbourne, Melbourne, Vic., Australia; Murdoch Children's Research Institute, Melbourne, Vic., Australia.
authors: Yves
authors: Y
authors: d'Udekem
authors: Women's and Children's Hospital, Adelaide, SA, Australia.
authors: Malcolm
authors: M
authors: Richardson
authors: Princess Margaret Hospital for Children, Perth, WA, Australia.
authors: Andrew
authors: A
authors: Bullock
authors: Royal Children's Hospital, Melbourne, Vic., Australia; University of Melbourne, Melbourne, Vic., Australia; Murdoch Children's Research Institute, Melbourne, Vic., Australia.
authors: Robert G
authors: RG
authors: Weintraub
authors: Royal Children's Hospital, Melbourne, Vic., Australia; University of Melbourne, Melbourne, Vic., Australia; Murdoch Children's Research Institute, Melbourne, Vic., Australia.
authors: Christian P
authors: CP
authors: Brizard
authors: Royal Children's Hospital, Melbourne, Vic., Australia; University of Melbourne, Melbourne, Vic., Australia; Murdoch Children's Research Institute, Melbourne, Vic., Australia. Electronic address: igor.konstantinov@rch.org.au.
authors: Igor E
authors: IE
authors: Konstantinov
mesh_terms: D000328:Adult; D000367:Age Factors; D001022:Aortic Valve Insufficiency / Q000401:mortality / Q000469:parasitology / Q000601:surgery; D006348:Cardiac Surgical Procedures; D002648:Child; D002675:Child, Preschool; D021922:Discrete Subaortic Stenosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D013318:Stroke Volume; D013997:Time Factors
keywords: Congenital heart disease; Subaortic stenosis; Surgery