Surgical Repair of Secondary Subaortic Stenosis in Congenital Heart Disease Without Initial Subaortic Obstruction
Keywords:congenital heart disease, secondary subaortic stenosis, left ventricular outflow tract, recurrence
Background: Secondary subaortic stenosis (SSS) is a rare heart disease of the left ventricular outflow tract (LVOT). It usually occurs after cardiovascular correction with or without initial left ventricular outflow tract obstruction (LVOTO). Because most patients with SSS are asymptomatic, many do not realize the need for reoperation until the obstruction worsens. Few studies suggest the characteristics and reasons of SSS without initial SAS. We conducted a retrospective study to describe the characteristics and surgical outcomes of these patients.
Methods: In this study, we examined a single-center retrospective cohort of SSS patients without initial SAS undergoing resection from 2010 to 2019. Patients are defined as secondary subaortic obstruction requiring surgery after cardiovascular correction. Demographics, perioperative findings, and clinical data were analyzed.
Results: Twenty-three patients had undergone secondary cardiac surgery for SSS without initial SAS during 10 years in our center. The median age at operation was 7.3 (4.0-13.5) years. In this study, the most commonly associated cardiac lesions were ventricular septal defect (VSD), atrioventricular septal defect (AVSD), patent ductus arteriosus (PDA), and coarctation arch hypoplasia (COA). The surgical techniques included membranous resection of five patients, fibromuscular resection of 17 patients, and reconstruction of the intraventricular baffle of one patient. The results of surgery in these patients are satisfied. The average LVOT gradient at the last follow up was 14.9 (7.8-26.2) mmHg. There was no operative mortality. Two patients had postoperative complications. The median follow-up period was 2.9 (1.1-4.3) years with one late death. Two patients (8.7%) had recurrence of stenosis.
Conclusions: Secondary subaortic stenosis is an uncommon heart disease. The reason is related to several causes, including missed diagnosis, unnoticed abnormalities of LVOT, and further changes of geometric morphology by intracardiac surgery. The results of surgery in these patients are satisfied. However, the recurrence of stenosis is still frequent.
Alsoufi B, Schlosser B, McCracken C, Sachdeva R, Kogon B, Border W, et al. 2016. Selective management strategy of interrupted aortic arch mitigates left ventricular outflow tract obstruction risk. J Thorac Cardiovasc Surg. Feb;151(2):412-20.
Anderson BR, Tingo JE, Glickstein JS, Chai PJ, Bacha EA, Torres AJ. 2017. When Is It Better to Wait? Surgical Timing and Recurrence Risk for Children Undergoing Repair of Subaortic Stenosis. Pediatr Cardiol. Aug;38(6):1106-1114.
Brauner R, Laks H, Drinkwater DC, et al. 1997. Benefits of Early Surgical Repair in Fixed Subaortic Stenosis. J Am Coll Cardiol. Dec;307(7).
Brauner R, Laks H, Drinkwater DC, Shvarts O, Eghbali K, Galindo A. 1997. Potential Role of Mechanical Stress in the Etiology of Pediatric Heart Disease: Septal Shear Stress in Subaortic Stenosis. J Am Coll Cardiol. Dec;30(7):1835-42.
Buratto E, Ye XT, Bullock A, Kelly A, d'Udekem Y, Brizard CP, et al. 2016. Long-term outcomes of reoperations following repair of partial atrioventricular septal defect. Eur J Cardiothorac Surg. Aug; 50(2):293-7.
Hirata Y, Chen JM, Quaegebeur JM, Mosca RS. 2009. The role of enucleation with or without septal myectomy for discrete subaortic stenosis. J Thorac Cardiovasc Surg. May;137(5):1168-72.
Kalfa D, Ghez O, Kreitmann B, Metras D. 2007. Secondary subaortic stenosis in heart defects without any initial subaortic obstruction: a multifactorial postoperative event. Eur J Cardiothorac Surg. Oct;32(4):582-7.
Kim CY, Kim WH, Kwak JG, Jang WS, Lee CH, Kim DJ, Lim C, et al. 2010. Surgical Management of Left Ventricular Outflow Tract Obstruction after Biventricular Repair of Double Outlet Right Ventricle. J Korean Med Sci. Mar; 25(3):374-9.
Mukadam S, Gordon BM, Olson JT, Newcombe JB, Hasaniya NW, Razzouk AJ, et al. 2018. Subaortic Stenosis Resection in Children: Emphasis on Recurrence and the Fate of the Aortic Valve. World J Pediatr Congenit Heart Surg. Sep;9(5):522-528.
Overman DM. 2014. Reoperation for Left Ventricular Outflow Tract Obstruction After Repair of Atrioventricular Septal. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 171(1).
Ruzmetov M, Vijay P, Rodefeld MD, Turrentine MW, Brown JW. 2006. Long-term results of surgical repair in patients with congenital subaortic stenosis. Interact Cardiovasc Thorac Surg. Jun;5(3):227-33.
Sigfússon G, Tacy TA, Vanauker MD, Cape EG. 1997. Abnormalities of the Left Ventricular Outflow Tract Associated with Discrete Subaortic Stenosis in Children: An Echocardiographic Study. J Am Coll Cardiol. Jul;30(1):255-9.
Valeske K, Huber C, Mueller M, Böning A, Hijjeh N, Schranz D, et al. 2011. The Dilemma of Subaortic Stenosis – A Single Center Experience of 15 Years with a Review of the Literature. Thorac Cardiovasc Surg. Aug;59(5):293-7.
Yang Y, Wang J, Qiao A, Fan X. 2020. Numerical Simulation of the Influence of Geometric Configurations on Pressure Difference in the Intraventricular Tunnel. Front Physiol. Feb 21;11:133.
Zhang X, Wang W, Yan J, Wang Q. 2020. Surgical treatment results of secondary tunnel-like subaortic stenosis after congenital heart disease operations: A 7-year, single-center experience in 25 patients. J Card Surg. Feb; 35(2):335-340.