Surgical management of complex and tunnel-like subaortic stenosis

Background: Relief of primary or secondary subaortic stenosis (SAS) remains a surgical challenge. Heart block, aortic valve regurgitation and recurren t obstruction have been persistent problems. Methods: Forty six patients wh o underwent surgery for complex and tunnel-like SAS between January 1990 an d November 1998 were reviewed. In 45 of the 46 patients SAS developed follo wing repair of a primary congenital heart defect and only one patient prese nted 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 un dergone repair of a variety of defects. The median age at the time of surge ry 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-p reserving procedure in conjunction with mitral valve replacement. Results: There were no deaths. None of the patients had an exacerbation of aortic re gurgitation and none developed complete heart block. The median follow-up w as 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 echo cardiography. Freedom from SAS at 1, 3 and 5 years was 100, 94 and 86%, res pectively Conclusions: We favor the modified Konno procedure and conal rese ction to the Konno or the Ross procedure, since insertion of a prosthetic v alve or homograft is avoided and aortic valve function is preserved. Excell ent relief of tunnel-like SAS can be achieved without damage to the conduct ion tissue. (C) 2000 Published by Elsevier Science B.V.