The surgical anatomy of the left ventricular outflow tract in hearts with ventricular septal defect and aortic arch obstruction

Growth of left ventricular outflow tract and predictors of future re-intervention after repair for ventricular septal defect and aortic arch obstruction

Ventricular septal defect and aortic arch obstruction are usually associated with a narrow left ventricular outflow tract. The aim of the present study was to analyse the growth and predictors of future obstruction of the left ventricular outflow tract after surgical repair.

METHODS

We carried out a retrospective review of patients who underwent repair for ventricular septal defect and aortic arch obstruction - coarctation or interrupted aortic arch - between July, 2002 and June, 2013. Echocardiographic data were reviewed, and the need for re-intervention was evaluated.

RESULTS

A total of 89 patients were included in this study. A significant left ventricular outflow tract growth was noticed after surgical repair. Preoperatively, the mean left ventricular outflow tract Z-score was -1.46±1 (range -5.5 to 1.1) and increased to a mean value of -0.7±1.3 (range -2.7 to 3.2) at last follow-up (p=0.0001), demonstrating relevant growth of the left ventricular outflow tract after repair for ventricular septal defect and aortic arch obstruction. After primary repair, 11 patients (12.3%) required re-intervention with surgical repair for left ventricular outflow tract obstruction after a mean period of 36±21 months. There were no significant differences in age, weight, and indexed aortic valve and left ventricular outflow tract measurements between those who developed obstruction and those who did not.

CONCLUSION

Significant left ventricular outflow tract growth is expected after repair of ventricular septal defect and aortic arch obstruction. Small aortic valve and left ventricular outflow tract at diagnosis are not risk factors to predict the need for surgical re-intervention for left ventricular outflow tract obstruction in future.

Risk factors associated with mortality and interventions in 472 neonates with interrupted aortic arch: A Congenital Heart Surgeons Society study

OBJECTIVE

We sought to determine the prevalence of outcomes and associated patient and management factors for neonates with interrupted aortic arch.

METHODS

From 1987 to 1997, a total of 472 neonates were enrolled prospectively from 33 institutions. Competing risks methodology was used to determine simultaneous risk and associated incremental risk factors for death, initial and subsequent left ventricular outflow tract procedures, and arch reinterventions.

RESULTS

Overall survival was 59% at 16 years after study entry but improved with successive birth cohort. In general, risk factors for death in each of the competing risks analyses included lower birth weight, younger age at study entry, type B interrupted aortic arch, and major associated cardiac anomalies. Of 453 patients who had interrupted aortic arch repair, after 16 years 33% had died and 28% had undergone an arch reintervention. Reintervention was more likely for those who had truncus arteriosus repair, interrupted aortic arch repair by a method other than direct anastomosis with patch augmentation, and the use of polytetrafluoroethylene as either an interposition graft or a patch. From study entry, competing risks after 16 years showed that 28% had died and 34% had undergone an initial left ventricular outflow tract procedure. Initial left ventricular outflow tract procedure was more likely for those with single ventricle, type B interrupted aortic arch, bicuspid aortic valve, or anomalous right subclavian artery. Among those who had undergone an initial left ventricular outflow tract procedure, after 16 years 37% had died and 28% had undergone a second procedure.

CONCLUSION

Anatomic features affect mortality and initial left ventricular outflow tract procedures, whereas characteristics of the arch repair affect arch reintervention.