title: Surgical management of complex and tunnel-like subaortic stenosis.
abstract: BACKGROUND
  Relief of primary or secondary subaortic stenosis (SAS) remains a surgical challenge. Heart block, aortic valve regurgitation and recurrent obstruction have been persistent problems.
  
  
  METHODS
  Forty six patients who underwent surgery for complex and tunnel-like SAS between January 1990 and November 1998 were reviewed. In 45 of the 46 patients SAS developed following repair of a primary congenital heart defect and only one patient presented with de novo tunnel-like SAS. Fifteen of the 45 patients had undergone repair of double-outlet right ventricle (DORV) and the remaining 30 had undergone repair of a variety of defects. The median age at the time of surgery was 5 years. The modified Konno procedure was performed in 15 patients, Konno procedure in three, Ross-Konno procedure in two and resection of the conal septum in 12 patients. Five patients with DORV underwent replacement of the intraventricular baffle and two patients underwent an aortic valve-preserving procedure in conjunction with mitral valve replacement.
  
  
  RESULTS
  There were no deaths. None of the patients had an exacerbation of aortic regurgitation and none developed complete heart block. The median follow-up was 3 years (range 1 month-8.5 years). Two patients developed recurrent SAS defined as a gradient of 40 mmHg or greater diagnosed by transthoracic echocardiography. Freedom from SAS at 1, 3 and 5 years was 100, 94 and 86%, respectively.
  
  
  CONCLUSIONS
  We favor the modified Konno procedure and conal resection to the Konno or the Ross procedure, since insertion of a prosthetic valve or homograft is avoided and aortic valve function is preserved. Excellent relief of tunnel-like SAS can be achieved without damage to the conduction tissue.
authors.affiliation: Department of Cardiac Surgery, Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: M
authors.initials: M
authors.lastname: Jahangiri
authors.forename: I A
authors.initials: IA
authors.lastname: Nicholson
authors.forename: P J
authors.initials: PJ
authors.lastname: del Nido
authors.forename: J E
authors.initials: JE
authors.lastname: Mayer
authors.forename: R A
authors.initials: RA
authors.lastname: Jonas
mesh_terms: D001020:Aortic Stenosis, Subvalvular / Q000000981:diagnostic imaging / Q000601:surgery*; D001021:Aortic Valve / Q000601:surgery; D006348:Cardiac Surgical Procedures / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D004452:Echocardiography; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000601:surgery*