Preoperative Factors That Predict Recurrence After Repair of Discrete Subaortic Stenosis

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.

Perioperative and Anesthetic Considerations in Pediatric Valvar and Subvalvar Aortic Stenosis

Aortic stenosis (AS) is a common form of left ventricular outflow tract obstruction (LVOTO) in children with congenital heart disease. This review specifically considers the perioperative features of valvar (VAS) and subvalvar AS (subAS) in the pediatric patient. Although VAS and subAS share some clinical features and diagnostic approaches, they are distinct clinical entities with separate therapeutic options, which range from transcatheter intervention to surgical repair. We detail the pathophysiology of AS and highlight the range of treatment strategies with a focus on anesthetic considerations for the care of these patients before, during, and after intervention.

Incidence of Reoperation After Surgical Procedure for Left Ventricular Outflow Tract Obstruction in Children and Young Adults

BACKGROUND

The common causes of subaortic left ventricular outflow tract obstruction (LVOTO) are hypertrophic cardiomyopathy (HCM) and membranous/tunnel subaortic stenosis (SAS). Reoperation after corrective surgery may be due to recurrent disease, associated congenital defects, or complications of the initial procedure. This study compares the late outcomes of young patients with HCM and SAS.

METHODS

We studied clinical, echocardiographic, and operative data of patients ≤21 years of age at the time of surgery for LVOTO between August 1963 and August 2018. We stratified patients into HCM (n = 152) and congenital SAS (n = 63) groups and compared survival and cumulative incidence of reoperation.

RESULTS

At initial repair, patients with HCM were older than patients with SAS (median [interquartile range] age, 15 [10-19] years vs 8 [5-13] years; P < .001), and patients with HCM were more symptomatic with dyspnea (P < .001), chest pain (P = .002), and presyncope/syncope (P = .005). Thirty-day mortality was 1.3% vs 0% for HCM and SAS groups. During a median follow-up of 13.1 years, survival was similar through the first 10 years; but during the second decade, patients with HCM had poorer survival (survival at 20 years, 80% vs 91% for patients with SAS; P = .007). Ten years after repair, reoperation for recurrent LVOTO was performed in 5% of patients with HCM vs 31% in those with SAS (P < .001).

CONCLUSIONS

In this surgical cohort, patients with HCM were more symptomatic preoperatively than those with SAS. Late survival of patients with SAS was superior to that of patients with HCM despite a greater need for reoperation.

A Case Report of Recurrent Subaortic Membrane in a 3-Year-Old Saudi Child

INTRODUCTION

While only a few cases have been reported in pediatrics, subaortic stenosis (SAS) is a gradually progressive disorder rarely seen at birth and infancy, however, it is the most common type of aortic stenosis. It obstructs the blood flow across the left ventricular outflow tract (LVOT). Although the cause is still not well known, different etiologies have been suggested by the literature. While surgical resection is the definitive treatment, recurrence is observed in many patients, nonetheless, LVOT gradient usually progresses over years of follow-up.

CASE PRESENTATION

We report the clinical and diagnostic course of a 41-months-old Saudi boy, asymptomatic child who was found to have progressive recurrent subaortic stenosis within a few months which required two redo sternotomy for sub-aortic membrane resection throughout a period of two years.

DISCUSSION

SAS is usually detected incidentally in asymptomatic patients requiring an echocardiogram to assess other accompanying congenital heart defects (CHD), or rather potentially arising after repair of CHD. Patient close monitoring is important aspect given the nature of disease progression, re-operation for recurrence demonstrate significant increase over years, re-resection rate was 0 % after one year, 6 % after five years, and 8 % after 10 years.

CONCLUSION

Recurrence of LVOT obstruction following sub-aortic membrane resection is common. Long-term follow-up care in postoperative patients is crucial. Majority of patients will need re-operation for recurrence at certain point during course of the disease.

Managing uncertainty in decision-making of common congenital cardiac defects

Decision-making in congenital cardiac care, although sometimes appearing simple, may prove challenging due to lack of data, uncertainty about outcomes, underlying heuristics, and potential biases in how we reach decisions. We report on the decision-making complexities and uncertainty in management of five commonly encountered congenital cardiac problems: indications for and timing of treatment of subaortic stenosis, closure or observation of small ventricular septal defects, management of new-onset aortic regurgitation in ventricular septal defect, management of anomalous aortic origin of a coronary artery in an asymptomatic patient, and indications for operating on a single anomalously draining pulmonary vein. The strategy underpinning each lesion and the indications for and against intervention are outlined. Areas of uncertainty are clearly delineated. Even in the presence of "simple" congenital cardiac lesions, uncertainty exists in decision-making. Awareness and acceptance of uncertainty is first required to facilitate efforts at mitigation. Strategies to circumvent uncertainty in these scenarios include greater availability of evidence-based medicine, larger datasets, standardised clinical assessment and management protocols, and potentially the incorporation of artificial intelligence into the decision-making process.

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.

Adult Presentation of Subaortic Stenosis with Subaortic Membrane Treated with Surgical Removal

Subaortic stenosis (SAS) is a rare heart disease in adults with an unclear etiology and variable clinical presentation. In some cases, SAS appears as hypertrophic cardiomyopathy with obstruction due to the accompanying systolic anterior motion of the mitral valve. A 46-year-old male with dizziness for several months presented in the outpatient department. Two-dimensional transthoracic echocardiography demonstrated a slightly hypertrophic left ventricle with normal systolic function without wall-motion abnormalities. Just below the aortic valve, a linear structure protruding from the septum side and the left-ventricular outflow tract (LVOT) side of the mitral valve was confirmed, which was causing a significant pressure gradient (mean and maximum of 91 mmHg and 138 mmHg, respectively). A diagnosis of SAS with subaortic membrane was made, and surgical myomectomy and subaortic membrane removal surgery were performed. Postoperative transthoracic echocardiography did not show flow acceleration through the LVOT, nor a significant pressure gradient across the aortic valve. This case report highlights the clinical significance of SAS with subaortic membrane, which can be confused with aortic stenosis of other etiology.

Adult Presentation of Subaortic Stenosis with Subaortic Membrane Treated with Surgical Removal

Subaortic stenosis (SAS) is a rare heart disease in adults with an unclear etiology and variable clinical presentation. In some cases, SAS appears as hypertrophic cardiomyopathy with obstruction due to the accompanying systolic anterior motion of the mitral valve. A 46-year-old male with dizziness for several months presented in the outpatient department. Two-dimensional transthoracic echocardiography demonstrated a slightly hypertrophic left ventricle with normal systolic function without wall-motion abnormalities. Just below the aortic valve, a linear structure protruding from the septum side and the left-ventricular outflow tract (LVOT) side of the mitral valve was confirmed, which was causing a significant pressure gradient (mean and maximum of 91 mmHg and 138 mmHg, respectively). A diagnosis of SAS with subaortic membrane was made, and surgical myomectomy and subaortic membrane removal surgery were performed. Postoperative transthoracic echocardiography did not show flow acceleration through the LVOT, nor a significant pressure gradient across the aortic valve. This case report highlights the clinical significance of SAS with subaortic membrane, which can be confused with aortic stenosis of other etiology.

Surgical repair of subaortic stenosis resection: 10 years of single-center experience in 65 patients

BACKGROUND

Subaortic stenosis (SAS) was a rare congenital heart disease of left ventricular outflow tract (LVOT), ranging from "isolated" lesions to "tunnel" or "diffuse" lesions. We conducted a retrospective study to describe the characteristics of patients with different lesions and analyze the risk factors for reoperation.

METHODS

In this study, we examined a single-center retrospective cohort of SAS patients undergoing resection from 2010 to 2019. Patients were classified as simple lesion group (n = 37) or complex lesion group (n = 28). Demographics, perioperative findings, and clinical data were analyzed.

RESULTS

The surgical effect of the two groups was significantly lower than that before the operation (p < .05). The median age at operation was 6 (3-11.8) years. There was no operative mortality. In complex lesion group, cardiopulmonary bypass time (CPB time), aortic cross-clamping time (ACC time), mechanical ventilation time, and intensive care unit (ICU) stay time were longer. The median follow-up period was 2.8 years (range: 1-3.8), with two late death. Six patients (9.2%) required reoperation due to restenosis or severe aortic insufficiency. The freedom from reoperation rates at 5 years was 66.7% for simple lesion but only 52.3% for complex lesion (p = .036).

CONCLUSIONS

Although the lesions include many forms, SAS resection was still satisfactory. However, the reoperation after initial surgical treatment was not infrequent, especially in patients with complex lesion.