[Epidemiological, clinical and echographic profile of patients operated for subvalvular aortic stenosis in the region of Sfax (Tunisia) and factors associated with postoperative recurrence: an observational study]. / Profil épidémiologique, clinique et échographique des patients opérés pour un rétrécissement aortique sous-valvulaire dans la région de Sfax (Tunisie) et facteurs associés à la récidive post-opératoire: étude observationnelle.

Subvalvular aortic stenosis is difficult to manage due to the evolutionary unpredictability of stenosis and a high recurrence rate after surgical treatment. The purpose of this study is to describe the profile of patients undergoing surgery for the treatment of aortic subvalvular stenosis and to investigate factors associated with post-operative recurrence of the subaortic obstacle. We conducted an observational study of all patients operated for subvalvular aortic stenosis, whose data were collected in the Department of Cardiology of the Sfax University Hospital between January 2010 and December 2020. The study involved 28 patients, with predominance of male sex (64.29%, n=18). At diagnosis, the mean age was 6.82 (±4.84) years and 19 patients (67.85%) had symptoms. On echocardiography, maximal subaortic gradient ≥50 mmHg was found in 23 patients (82.14%). Cardiovascular malformations associated with subvalvular stenosis were found in 16 patients (57.14%). The average age of patients at the time of surgery was 10.43 (±7.08) years. Subaortic membrane resection was the most commonly used technique (46.4%, n=13). It was associated with septal myomectomy in 8 patients (28.6%). Postoperative mortality rate was zero. Residual gradient ≥30 mmHg was reported in 8 patients (28.6%) after surgery. Recurrences were observed in 7 patients (25%) of whom 6 underwent reintervention. In multivariate analysis, only postoperative residual gradient was significantly associated with recurrence (p=0.030, OR=33.785, 95% CI: 1.398-816.754). Despite old age at diagnosis and surgery, favorable short-term outcomes were reported, but recurrences were frequent in the long term. This highlights the role of regular, perioperative and postoperative, clinical and echographic monitoring of these patients.

Surgical Repair of Secondary Subaortic Stenosis in Congenital Heart Disease Without Initial Subaortic Obstruction.

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.

Intraoperative transesophageal echocardiographic predictors of recurrent left ventricular outflow tract obstruction in children undergoing subaortic stenosis resection.

BACKGROUND: Intraoperative transesophageal echocardiography (iTEE) is used to assess for residual left ventricular outflow tract obstruction (LVOTO) after surgical resection of subaortic membrane causing subaortic stenosis (sub-AS). We aimed to identify the iTEE features associated with recurrence of LVOTO. METHODS: We conducted a retrospective study of children undergoing sub-AS resection from June 2006 to June 2014. Doppler assessment of the flow velocity and the anatomical features of the left ventricular outflow tract were analyzed from stored echocardiograms. Recurrent LVOTO was defined as an increase in the mean pressure gradient across the left ventricular outflow tract of > 15 mm Hg on the most recent follow-up echocardiogram from the mean pressure gradient on the predischarge echocardiogram or as doubling of the mean pressure gradient to a value ≥20 mm Hg. RESULTS: Thirty-five patients were included, with median age at surgery was 8.1 years (range: 0.7-29 years) and median follow-up was 47 months (2-91 months). Ten patients (29%) had recurrent LVOTO, which was associated with a shorter distance between the narrowest diameter of the outflow tract and the aortic valve on iTEE [median 0.59 cm (range 0.39-0.74) vs 0.98 cm (0.75-1.5), P = .03]. No patients with more than mild residual LVOTO on iTEE regressed to mild or no LVOTO on follow-up echocardiograms. CONCLUSIONS: LVOTO recurrence after sub-AS resection is common, and residual LVOTO remains the same or increases over time. Proximity of the LVOTO to the aortic valve is a risk factor for recurrent LVOTO. These findings may be useful in counseling patients and to guide the frequency of postoperative follow-up.

Subvalvular aortic stenosis: a review of current literature.

Subvalvular aortic stenosis (SAS) is one of the common adult congenital heart diseases, with a prevalence of 6.5%. It is usually diagnosed in the first decade of life. Echocardiography is the test of choice to diagnose SAS. Surgical correction is the best treatment modality, and the prognosis is usually excellent. In this review, we describe the pathophysiology, diagnosis, prognosis, and management of SAS with a focus on different pathophysiologic mechanisms, diagnostic approach, and prognosis of the disease by reviewing the current literature.

Paediatric subvalvular aortic stenosis: a systematic review and meta-analysis of natural history and surgical outcome.

Sub-valvular aortic stenosis (SAS) is a common form of left ventricular outflow tract (LVOT) obstruction, which can lead to aortic valve damage. Although surgery for SAS is an accepted treatment, the timing of surgical intervention of SAS remains controversial. This review aims to establish an overview of the natural history and outcome after surgery and factors associated with prognosis in paediatric SAS patients. We searched PubMed and EMBASE for studies that reported factors that negatively affected the prognosis of patients with SAS. Studies were included if they were written in English, published between 1 January 1997 and 31 December 2012 and the mean patient age was <18 years at the time of study entry. Studies were excluded if the study size was <20 patients. A distinction was made between natural history and surgical cohorts. Twenty-four studies were included in this review, encompassing a total of 809 natural history and 1476 surgical patients. Fifty-one percent of natural history patients required surgery. After surgery, there was a substantial reoperation rate. Higher LVOT gradient and the presence of aortic regurgitation (AR) were identified as the foremost independent predictors of a worse outcome. Valve-to-membrane distance was also found to be associated with prognosis, although the results were contradictory. This systematic review underlines the importance of LVOT gradient, aortic valve-to-membrane distance and AR in surgical decision-making in paediatric SAS patients. There is need for collaborative effort to further study the optimal timing of surgery based on LVOT gradient, valve-to-membrane distance and the presence of AR.

Surgery for simple and complex subaortic stenosis in children and young adults: results from a prospective, procedure-based national database.

OBJECTIVE: To identify the outcomes of surgically treated subaortic stenosis in a national population. METHODS: From 2000 to 2013, 1047 patients aged < 40 years underwent 1142 subaortic stenosis procedures. Of the 1047 patients, 484 (46.2%) were considered to have complex stenosis (CS) because at or before the first operation they had mitral valve (MV) disease, aortic valve disease, aortic coarctation or an interrupted aortic arch. RESULTS: The 30-day mortality was 0.7% for simple stenosis (SS), 2.3% for CS (P = .06), and 1.6% overall. Age < 1 year (P < .01), MV procedure (P = .02) and an interrupted aortic arch at the index procedure (P < .01) were risk factors for early death. Konno-type procedure early mortality was 2.4%. The 12-year survival was 97.1%, with a significant difference between SS and CS (hazard ratio [HR], 4.53; P = .02). Having MV disease alone (HR, 4.11; P = .02), MV disease plus aortic coarctation (HR, 6.73; P = .008), and age < 1 year (HR, 6.72; P < .001) were risk factors for late mortality. Freedom from subaortic reintervention overall was 92.3% and 88.5% at 5 and 12 years, respectively, much greater with CS than with SS (HR, 4.91; P < .0001). The independent risk factors for reintervention were younger age at the index procedure (HR, 0.1/y; P = .002), concomitant MV procedure (HR, 2.68; P = .019), ventricular septal defect plus interrupted aortic arch (HR, 3.19; P = .014), and ventricular septal defect plus aortic coarctation (HR, 2.41; P = .023). Undergoing a concomitant aortic valve procedure at the index procedure was protective (HR, 0.29; P = .025). CONCLUSIONS: Patients with SS had excellent outcomes. However, those with CS had worse long-term survival and freedom from reintervention, with morbidity and mortality greatest in young patients with multiple lesions. Additional evaluation in large-scale prospective studies is warranted.

Congenital discrete subaortic stenosis in pregnancy: case report and literature review.

Today's growing numbers of pregnant patients with congenital heart defects presents challenges for cardiologists treating adult patients. The case is presented of a 19-year-old woman who was admitted with a threatened miscarriage in the third trimester and was diagnosed with an incomplete atrioventricular canal, cleft mitral valve with severe regurgitation, and severe congenital subaortic stenosis caused by a subaortic membrane. She was managed conservatively, delivered via cesarean section, and then underwent surgical repair of all defects with good outcome. Here, a review is provided of the literature on the natural course, complications, and treatment strategies of subaortic stenosis, together with a summary of recommendations for the management of the condition.

Surgical management of subaortic stenosis.

A 63-year-old male patient with subaortic stenosis (Pmax 105 mmHg, Pmean 55 mmHg) and an aneurysm of the ascending aorta was referred to our hospital due to progressive angina pectoris. Transesophageal echocardiography demonstrated high and turbulent subaortic flow velocities. A calcified subaortic membrane was identified. The membrane was removed and the aneurysm was treated with a Bentall procedure. The patient recovered smoothly from surgery and was doing well 6 months after discharge.

Accessory mitral valve without subaortic obstruction of left ventricular outflow tract in a middle-aged male.

Accessory mitral valve (AMV) is a rare congenital abnormality with a usually early-age clinical onset, being potentially a cause of subvalvular obstruction of the left ventricular outflow tract. This report describes the case of a 60-year-old patient presented with palpitations and chest pain. Primary evaluation revealed a ventricular tachycardia episode while transthoracic echocardiography showed an intracardiac additional structure at the level of the left ventricular outflow tract. After transoesophageal echocardiography and paraclinical investigations this structure was proven to be an AMV tissue which did not provoke left ventricular outflow obstruction. This case presents an unusual late-age clinical onset of AMV without a clinically significant LVOT (left ventricular outflow tract) obstruction and highlights the importance of transthoracic and transoesophageal echocardiography in the diagnosis of this rare cardiological entity.

Surgical management of supravalvar aortic stenosis with coronary artery involvement.

Supravalvar aortic stenosis is characterized by an obstruction of the left ventricular outflow tract distal to the aortic valve. Its association with left main coronary artery stenosis is well known but right coronary artery involvement has not been reported. We describe two cases of supravalvar aortic stenosis with coronary artery stenosis and its surgical management.

Diffuse alveolar damage in a young cat.

A 10-month-old cat was diagnosed with congenital subvalvular aortic stenosis. To resolve its hypoxia, oxygen therapy was administered a couple of times a week during two months. The oxygen partial pressure in the chamber was maintained between 30 and 35%, and the time for one procedure was 12-24 hr. The animal died due to severe respiratory failure. At necropsy, the lungs were voluminous and had a rubbery texture. Histologically, large type II pneumocytes with occasional atypia had diffusely proliferated within the lungs. Interstitial fibrosis was not observed, although some alveolar septa were thickened along with fibrinous exudates and neutrophilic infiltration. The histology of these lesions was consistent with diffuse alveolar damage (DAD), which might have been partially due to oxygen toxicity.

The dilemma of subaortic stenosis--a single center experience of 15 years with a review of the literature.

OBJECTIVE: The term "subaortic stenosis" includes a variety of obstructions of the left ventricular outflow tract (LVOT), ranging from a short (discrete) subvalvular membrane to long, tunnel-like narrowing. An association with other congenital lesions is frequent. We reviewed the reported literature and describe our results, analyzing the nomenclature of and risk factors for restenosis after surgical treatment. METHODS: From 1994 to 2009, 81 children (53 males, 28 females; median age: 57 months, range [ R]: 5-204) underwent surgical relief of a subaortic stenosis. Patients were divided, according to pathology, into short segment (group A, n = 42) and complex obstructions (group B, n = 39), with the latter including long segment stenosis and/or associated anomalies such as aortic coarctation, interrupted aortic arch or Shone's complex. RESULTS: Surgery resulted in a significant reduction of the gradient between the left ventricle and the aorta in both groups (Δ P group A: 51 ± 28 mmHg, group B: 46 ± 25 mmHg). There was no operative mortality. One patient died in the early postoperative period due to pericardial tamponade. Median follow-up was 90 months (R = 0.5-187). Twenty-five (31%) patients required reoperation because of recurrent stenosis after a median of 43 months (R = 0.5-128). Seven (16%) patients belonging to group A developed restenosis, and 18 (46%) in group B. Freedom from reoperation for all patients was 60% after 10 years. 10 (40%) of the patients of group B were ultimately treated with a Ross-Konno reconstruction of the LVOT. CONCLUSION: Despite adequate surgical resection, recurrence of subaortic stenosis within several years after initial surgical treatment is frequent, especially in patients with complex lesions. In cases requiring reoperation, the surgical therapy is often extensive, and even includes Ross-Konno reconstruction of the LVOT.