Residual Lesions Linked to Postoperative Congenital Cardiac Surgery Outcomes

Fallot’s tetralogy. Colored X-ray of the chest of an infant with Fallot’s tetralogy and rickets. Fallot’s tetralogy is a congenital heart defect that results in insufficient oxygen in the blood (cyanosis), which can cause the baby to turn blue. It is caused by 4 malformations of the heart. There is a hole between the 2 bottom chambers (ventricles) of the heart, a narrowing of the valve leading to the pulmonary arteries, a thickening of the right ventricle and blood can enter the aorta from both ventricles, not only the left. Treatment is with a series of operations. Rickets, soft bones due to a lack of vitamin D, has lead to a misshapen chest. It is treated with vitamin D supplements.
This study evaluated factor associated with outcomes after cardiac surgery for congenital heart defects.

Residual lesions after congenital cardiac surgery are associated with in-hospital outcomes, with the greatest effects occurring after more complex operative procedures, according to a study recently published in the Journal of the American College of Cardiology.

This multicenter, prospective observational study included 1149 infants aged <1 year enrolled between 2015 and 2017 for 5 different types of cardiac operations (tetralogy of Fallot [TOF] with pulmonary stenosis repair, n=250; complete atrioventricular septal defect [CAVSD] repair, n=249; arterial switch operation, n=251; coarctation or hypoplastic or interrupted arch with ventricular septal defect [VSD] closure [Arch/VSD], n=150; Norwood operation, n=249). Residual lesion score (RLS) was categorized by clinical events postoperation, as well as by echocardiography.

RLS 1 was classified as trivial/no residual lesions, RLS 2 as minor lesions, and RLS 3 as major residual lesions requiring reintervention before discharge. The study’s primary outcome was alive and out-of-hospital days within 30 days of surgery (60 days for Norwood). Secondary outcomes included postoperative course, days in the hospital, and major medical events. Kruskal-Wallis and analysis of variance were used to assess continuous outcomes across RLS categories, while a Fisher exact test was used for categorical outcome comparison.

Although RLS 2 vs RLS 1 was not consistently significant for different outcomes across operations, categorization of RLS 3 vs RLS 1 was associated with worse outcomes for days alive and out of hospital as well as postoperation stay in hospital. RLS 3 vs RLS 1 was also associated with poorer secondary outcomes following coarctation/interrupted arch with VSD repair and Norwood. RLS accounted for 5% of the variation of the least complex surgery, TOF, and 20% in the most complex operation, Norwood.

Limitations to this study included a small amount of missing data, diverse major medical events, the use of local interpretation for the arterial switch operation, uncertain generalizability of the study’s findings, and a focus on early postoperative (rather than medium- or long-term) outcomes.

“Major residual lesions were most strongly associated with worse in-hospital outcomes in the most complex operations but had less predictive value for operations of lower complexity”, the study authors noted.


Nathan M, Levine JC, Van Rompay MI, et al.; for the Pediatric Heart Network Investigators. Impact of major residual lesions on outcomes after surgery for congenital heart disease. J Am Coll Cardiol. 2021;77:2382-94.