FIG 44.28 Surgical approaches for patients with discrete subaortic stenosis (subAS) based on size and function of the aortic valve (AoV) LVOTO, Left ventricular outflow tract obstruction In the majority of cases, circumferential excision of the fibrous ridge with septal myectomy provides efficient relief of obstruction (Video 44.18) A modified Konno operation, which involves myectomy, resection of fibrous subaortic tissue, and creation of a ventricular septal defect that is patch closed, provides effective relieve of subaortic obstruction if the aortic annulus and valve are normally developed The Ross-Konno operation is the procedure of choice in children with a multilevel type of left ventricular outflow tract obstruction and severe abnormality of the aortic valve (Video 44.19) Long-Term Outcomes Early surgical mortality following repair of discrete subaortic membrane is low, less than 5%, with the survival rate greater than 90% at 15 years.184 However, patients are at risk for both recurrence of subaortic stenosis and progressive aortic regurgitation Need for reoperation for recurrence of subaortic stenosis after resection of a discrete subaortic membrane ranges from 7.1% to 20%.182,185,186 The risk for recurrence is less when membrane resection is accompanied by myectomy compared with membrane resection alone.187 Aggressive resection of all structures causing flow turbulence (anomalous septal insertion of the mitral valve, accessory mitral valve tissue, anomalous papillary muscle, anomalous muscular band, etc.) and removal of pathologic tissue from the valve leaflets and from the subcommissural trigones may prevent the development or progression of aortic regurgitation and may eliminate the substrate for recurrent obstruction.188 Aortic regurgitation may progress even after successful repair of the subaortic stenosis.182 Postoperative complete heart block is a complication when there is too aggressive an approach during extended, circumferential myectomy Annotated References Anderson RH Demystifying the anatomic arrangement of the aortic valve Eur J Cardiothorac Surg 2006;29(6):1006–1007 A publication showing that the leaflets of the aortic valve are suspended in a semilunar fashion within the aortic root, making it difficult to describe any part of the root consistently in terms of an annulus Prakash SK, Bosse Y, Muehlschlegel JD, et al A roadmap to investigate the genetic basis of bicuspid aortic valve and its complications: insights from the international BAVCon (bicuspid aortic valve consortium) J Am Coll Cardiol 2014;64(8):832–839 A review article that discusses the complex inheritance patterns and the current understanding of the genetic etiology of bicuspid aortic valve disease Nishimura RA, Otto CM, Bonow RO, et al 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American heart association task force on practice guidelines J Am Coll Cardiol 2014;63(22):e57– ... AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/ American heart association task force on practice guidelines J Am Coll Cardiol 2014;63(22):e57–