Reoperation after isolated subaortic membrane resection

The prognostic significance of early troponin levels in patients undergoing aortic ridge surgery

Subaortic stenosis is a CHD that can lead to left ventricular hypertrophy, heart failure, and aortic valve damage if left untreated. The gold standard treatment for subaortic stenosis is septal myectomy. However, there is no clear consensus on the surgical margins required for adequate muscle resection. In this retrospective study, we reviewed the records of 83 patients who underwent subaortic stenosis surgery between 2012 and 2020 to investigate the effect of early troponin levels on prognosis. We excluded patients with additional cardiac pathologies, hypertrophic obstructive cardiomyopathy, and valvular aortic stenosis.Troponin levels were recorded in the early post-operative period, and patients were monitored for complications such as ventricular arrhythmia, left ventricular systolic dysfunction, infective endocarditis, and pacemaker implantation. The troponin levels were significantly higher in the patients who had septal myectomy. The degree of myectomy affected the risk of complications in the early post-operative period and recurrence in the later period. However, when the gradient was substantially or completely removed by myectomy, patients experienced significant symptom improvement in the early post-operative period, and their late survival was equivalent to that of healthy individuals of the same age.Our findings suggest that monitoring troponin levels in patients undergoing septal myectomy may be beneficial in predicting the risk of complications. However, further studies are needed to establish the optimal surgical technique and extent of muscle resection required for subaortic stenosis treatment. Our study adds to the existing knowledge of the benefits and risks associated with septal myectomy as a treatment option for subaortic stenosis.

Subaortic Stenosis in Adult Patients With Atrioventricular Septal Defect

BACKGROUND

Patients with atrioventricular septal defects (AVSD) are at risk for development of subaortic stenosis throughout their lifetime. The early and midterm outcomes of adults with AVSD undergoing primary operation or reoperation for subaortic stenosis remain unknown.

METHODS

All patients aged 18 years or more with partial or complete AVSD who underwent operation for subaortic stenosis at our institution from 1992 to 2020 were retrospectively reviewed.

RESULTS

Nineteen patients were identified: 15 patients with partial AVSD (79%); 3 (16%) with complete AVSD; and 1 (5%) with transitional AVSD. Fifteen patients (79%) had previously corrected AVSD (median 8 years; interquartile range, 3.6-23.1) and 7 (37%) had previous repair of subaortic stenosis. The mechanism for obstruction included subaortic membrane (n = 19, 100%); septal hypertrophy (n = 11, 58%); anomalous papillary muscle, chordae, or left atrioventricular valve tissue (n = 9, 47%); and tunnel obstruction (n = 5, 26%). All patients underwent transaortic membrane resection, and septal myectomy was done in 18 patients (95%). There was no early mortality. During follow-up (median 8.3 years, maximum 28), survival was 100% at 5 years and 95% at 10 years. One patient required reintervention for subaortic stenosis 15 years after the operation at our institution.

CONCLUSIONS

Surgical correction of subaortic obstruction in adult patients with AVSD can be accomplished with low morbidity and mortality. Subaortic stenosis can appear late after the initial repair of AVSD, and these patients remain at risk for recurrence after resection.

Long-term follow-up of subvalvular aortic stenosis in children: a single-centre experience

OBJECTIVE

The aim of this study is to evaluate clinical and surgical outcomes of children with subaortic stenosis, to determine the risk factors for surgery and reoperation and to compare isolated subaortic stenosis and those concomitant with CHDs.

METHODS

The study involved 80 children with subaortic stenosis. The patients were first classified as isolated and CHD group, and the isolated group was further classified as membranous/fibromuscular group. The initial, pre-operative, post-operative and the most recent echocardiographic data, demographic properties and follow-up results of the groups were analysed and compared. The correlation of echocardiographic parameters with surgery and reoperation was evaluated.

RESULTS

There was a significant male predominance in all groups. The frequency of the membranous type was higher than the fibromuscular type in the whole and the CHD group. The median time to the first operation was 4.6 years. Thirty-five (43.7%) patients underwent surgery, 5 of 35 (14%) patients required reoperation. The rate of surgery was similar between groups, but reoperation was significantly higher in the isolated group. The gradient was the most important factor for surgery and reoperation in both groups. In the isolated group besides gradient, mitral-aortic separation was the only echocardiographic parameter correlated with surgery and reoperation.

CONCLUSION

Reoperation is higher in isolated subaortic stenosis but similar in membranous and fibromuscular types. Early surgery may be beneficial in preventing aortic insufficiency but does not affect the rate of reoperation. Higher initial gradients are associated with adverse outcomes, recurrence and reoperation.

The Surgeon's View of the Left Ventricular Outflow Tract in Congenital Heart Surgery

Left ventricular outflow tract (LVOT) obstruction is a component of many forms of congenital heart disease, including hypertrophic cardiomyopathy, membranous subaortic stenosis, tunnel subaortic stenosis, and outflow tract obstruction related to atrioventricular septal defects. We have gained a particularly extensive experience with the diagnosis and treatment of hypertrophic cardiomyopathy, having performed septal myectomy in over 3,800 patients. In the setting of this review of LVOT obstruction, we use hypertrophic cardiomyopathy as a template by which other pathologies causing LVOT obstruction can be understood. We review important surgical issues in patient selection, diagnostic evaluation, interpretation of imaging, and operative management. To this end, the review focuses on obstructive hypertrophic cardiomyopathy and then broadens to discuss other pathologies causing LVOT obstruction, with important similarities and differences in their management. These other pathologies share some similar presentations and operative techniques, and at times can be confused with hypertrophic cardiomyopathy, but also have important distinctions of which the surgeon should be aware.