Membranous Subaortic Stenosis Research Articles

Clinical features and surgical outcomes of membranous subaortic stenosis in three siblings: a case series and literature review

Introduction: Subvalvular aortic stenosis (SAS) is a rare heart condition that can cause LVOT obstruction and lead to serious complications. While surgery is the main treatment, recurrence is a concern. This case series highlights the challenges in managing SAS in young patients. Case Series: Three young brothers presented with symptoms of shortness of breath and chest tightness. All were diagnosed with membranous SAS through echocardiography and Doppler ultrasound. Surgical intervention was performed to remove the obstruction, but all three patients experienced recurrence within two years. Discussion: This case series of three brothers suggests a genetic predisposition. Symptoms included exertional dyspnea and chest tightness, diagnosed via echocardiography. Surgical intervention is the primary treatment, but its timing is debated due to recurrence risks and complications. Conclusions: This case series suggests a possible genetic predisposition to SAS. Despite successful initial surgery, the high recurrence rate highlights the need for improved management strategies and long-term follow-up. Further research is crucial to understand the causes of recurrence and optimize treatment for children with SAS.

AN UNEXPECTED INTRAOPERATIVE UNUSUAL CASE OF AORTIC STENOSIS

Introduction Aortic stenosis is the most frequent valvular pathology in the developed countries (1). It is most often due to the calcified or degenerated aortic valve as a manifestation of ageing. Sub-valvular aortic stenosis is rare in the adult population being more common in children accounting for 8-20% of left ventricular outflow tract (LVOT) obstructions (2). Stenosis degree may change depending on the malformation varying from a minor ridge to a complete fibrous ring or tunnel. Although proper timing for surgery is unclear, diagnosis might be more difficult in the adult patient with transthoracic echocardiography as subvalvular portions of the LVOT might be shaded by calcium and difficult to visualize. We report a case of a 65 years old lady diagnosed with severe aortic stenosis and scheduled for aortic valve surgery. Methods The patient presented to our department with recent history of shortness of breath and clinical and transthoracic echocardiographic diagnosis os severe aortic stenosis. The maximum blood velocity across the aortic valve was 4.8 m sec-1 at continuous Doppler sampling. She was scheduled for aortic valve replacement. After establishing hemodynamic monitoring, general anaesthesia induction was performed with remifentanil, propofol and cisatracurium and maintained as TIVA. According to our protocol, a transesophageal echocardiography (TEE) was positioned and a baseline TEE was performed. Results TEE demonstrated a massive concentric hypertrophy of the left ventricle, a membranous subaortic stenosis and a normal aortic valve (fig. 1A,1B,1C). Surgery was then halted as the patient's written consent had been obtained for a valve replacement. Then the patient was further investigated by ECG gated cardiac CT scan, which confirmed the subvalvular membrane. The patient was then operated to remove the subvalvular membrane and a partial septal myectomy was also executed (fig 1D). She completely recovered and was discharged home on p.o. day 5. Discussion Differential diagnosis between aortic valvular stenosis or stenosis due to a subvalvular obstruction might be tricky, but is crucial for the operation result. TEE 2D and 3D imaging recognised the anomaly prior to surgery and so allowed to properly address the cardiac disease leading to post-operative success. Perioperative TEE should be performed in a systematic manner according to the current guidelines (3), but beyond the level of re-confirming the expected findings prior to surgery. TEE allowed for rapid and thorough recognition of previously undiscovered pathology leading to proper patient's management and case resolution, so confirming the importance of perioperative TEE in the setting of surgical treatment of heart valve diseases.

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.

Successful Percutaneous Balloon Dilatation of Membranous Sub-aortic Stenosis in a 22 Year Old Pregnant Patient

Congenital obstruction of the left ventricular outflow tract comprises a heterogeneous group of disorders, with obstruction potentially occurring below, above, or at the level of the aortic valve. Subvalvular stenosis is the second most common type of left ventricular outflow tract obstruction, of which discrete membranous type is the most common. Although surgical resection of the subaortic membrane is the treatment of choice in discrete membranous subaortic stenosis, in selected patients with isolated membranous subaortic stenosis, without significant aortic insufficiency, percutaneous balloon tearing of the membrane results in reduction in the degree of left ventricular outflow tract obstruction and symptomatic relief. We report a case of 22 year old pregnant patient admitted with NYHA class III breathlessness, found to have discrete membranous subaortic stenosis. Balloon aortic valvuloplasty was performed in the patient with good result. Patient underwent normal vaginal delivery at 38 weeks. Both mother and newborn were asymptomatic. Patient is asymptomatic on subsequent follow-ups.

Outcome in Children Operated for Membranous Subaortic Stenosis: Membrane Resection Plus Aggressive Septal Myectomy Versus Membrane Resection Alone.

The optimal surgical procedure for treatment of fibromembranous subaortic stenosis has been a subject of debate. We report our experience with patients treated for membranous subaortic stenosis using membrane resection alone and membrane resection plus aggressive septal myectomy. Patients followed in the pediatric cardiology clinic of a university hospital, who had undergone surgery for subaortic stenosis between 2002 and 2013 were reviewed. Recurrence of subaortic membrane, residual left ventricular outflow gradient, and aortic valve function were analyzed. Forty-six patients underwent surgery for subaortic membrane. Of these, 19 had membrane resection plus aggressive septal myectomy, while 27 had membrane resection alone. Mean age at surgery for the membrane resection group was 7.7 ± 3.9 years and 10.9 ± 3.6 years for the membrane resection plus aggressive myectomy group. Preoperative subaortic gradient for the membrane resection group was 75.5 ± 26.7 mm Hg and 103.2 ± 39.7 mm Hg for the membrane resection plus aggressive myectomy group. The mean follow-up left ventricular outflow tract gradient was 42.3 ± 31.3 mm Hg in the membrane resection group, while it was 11.6 ± 6.3 mm Hg in the aggressive septal myectomy group. Nine patients from the membrane resection group had significant regrowth of the subaortic membrane during the follow-up period, while none of the aggressive septal myectomy group had detectable membrane on echocardiography. Seven of the nine patients with recurrence of the subaortic membrane underwent subsequent membrane resection plus aggressive septal myectomy. Intraoperative finding in all these redo cases was recurrence (growth) of a subaortic membrane. Aggressive septal myectomy offers less chance of recurrence, freedom from reoperation, and an improved aortic valve function. This is especially important in sub-Saharan settings where a chance of getting a second surgery is unpredictable.

Invited Commentary: Outcome in Children Operated for Membranous Subaortic Stenosis: Membrane Resection Plus Aggressive Septal Myectomy Versus Membrane Resection Alone: Subaortic Stenosis--How Deep Should the Knife Go?

Invited Commentary: Outcome in Children Operated for Membranous Subaortic Stenosis: Membrane Resection Plus Aggressive Septal Myectomy Versus Membrane Resection Alone: Subaortic Stenosis--How Deep Should the Knife Go?

Atypical Shone’s Complex Diagnosed by Echocardiography

Shone's complex is a rare and severe type of congenital left-sided obstructive lesion of multiple cardiovascular levels. This report aims to present the authors' experience diagnosing atypical Shone's complex using echocardiography. Atypical Shone's complex was diagnosed for 38 consecutive patients (18 boys and 20 girls, ages 1 day to 15 years) using echocardiography. All the diagnoses were confirmed by cardioangiography, surgery, or both. Among the congenital left-sided obstructive lesions, four levels of obstruction coexisted in 3 cases (7.9%), three levels in 10 cases (26.3%), and two levels in 25 cases (65.8%). Supra-annular mitral stenosis caused by a supravalvular mitral ring was diagnosed in 1 case. Mitral valvular stenosis was diagnosed in 24 cases including a parachute mitral valve (4 cases), a double-orifice mitral valve (1 case), and partly fused thickened mitral valvular leaflets (19 cases). Subaortic stenosis was diagnosed in 10 cases including circumferential membranous subaortic stenosis (1 case), tunnel-type subaortic narrowing (2 cases), and asymmetric obstructive fibrous ridge below the aortic valve (7 cases). Aortic stenosis was diagnosed in 25 cases including the bicuspid aortic valve (12 cases), the hypoplasia aortic annulus (3 cases), and partly fused or thickened tri-leaflet aortic valves (10 cases). Supra-aortic stenosis was diagnosed in 6 cases including the localized type (4 cases) and the diffused type (2 cases). Coarctation of the aorta was diagnosed in 26 cases. Of these, focal coarctation was described in 15 cases, long segment coarctation in 7 cases, and dysplastic isthmus and/or descending aorta in 4 cases. Secondary changes in Shone's complex manifested as left atrial dilation (26 cases), left ventricular hypertrophy (26 cases), and pulmonary hypertension (19 cases). Echocardiography plays an important role in the diagnosis of atypical Shone's complex, in comprehensive evaluation of the number, position, morphology, and severity of left-sided obstructions.

Medical Management of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. The underlying cause of HCM has been attributed to a number of mutations within genes encoding primarily for sarcomeric proteins, which lead to a heterogeneous phenotype of left ventricular hypertrophy in the absence of other causes (eg, hypertension, aortic stenosis, or a discrete membranous subaortic stenosis). Symptoms may range from mild to severely limiting and consist of dyspnea and chest pain with exertion or at rest, syncope, or even sudden cardiac death (SCD). The majority of patients with HCM are treated medically. The primary aim of therapy is to reduce symptoms, but it should also address the risk of SCD. Throughout the years, numerous medical treatments have been used to achieve symptom control in these patients, and include medications such as β-blockers, calcium channel blockers, amiodarone, disopyramide, and angiotensin receptor blockers. This review provides an overview of the current medical treatment of HCM.

Noninvasive Evaluation of Membranous Subaortic Stenosis: Complimentary Roles of Echocardiography and Computed Tomographic Angiography

A 29-year-old Ethiopian woman that was referred to the Wisconsin Heart Hospital for treatment of subaortic stenosis, diagnosed 4 years earlier, in Ethiopia, using transthoracic echocardiography. Preoperative evaluation included transesophageal echocardiography, which showed severe membranous subaortic stenosis with a mean outflow gradient of 70 mmHg. Cardiac computed tomographic angiography also demonstrated a subaortic membrane, and additionally showed normal epicardial coronary arteries. The patient underwent uneventful surgical resection of the subaortic membrane without undergoing cardiac catheterization.

Discrete Membranous Subaortic Stenosis Complicated by Infective Endocarditis: A Case Report

Discrete membraneous subaortic stenosis is an uncommon cause of left ventricular outflow tract obstruction. Although its relationship to infective endocarditis is well defined, the expected site of vegetation is over the aortic valve. We report on a 46-year-old man who had a discrete membranous subaortic stenosis, complicated with infective endocarditis, in which the vegetation was over the subaortic membrane and the aortic valve was spared. To our knowledge, this is the first reported case of that entity.

Familial membranous subaortic stenosis: Review of familial inheritance patterns and a case report

Discrete subaortic stenosis (DSS) accounts for 8% to 20% of all cases of left ventricular outflow tract (LVOT) obstruction. 1 Familial incidence of DSS, although very rare, signifies the importance of screening in family members. Thus far, a clear inheritance pattern has not been reported in any single pedigree. We have described a family with 2 affected children (out of 3) and have also reviewed the inheritance patterns observed in the reported familial cases of DSS. Most cases of DSS present with systolic murmurs and with time progress to systolic dysfunction. Therefore we also explored the relationship between age and the peak LVOT pressure gradient in the familial cases. Clinical Summary PATIENT 1. A 3-month-old infant presented with recurrent pulmonary infections, congestive heart failure, and failure to thrive. On examination, he had a machinery murmur. Echocardiography revealed a large patent ductus arteriosus, mild pericardial effusion, severe left ventricular hypertrophy (LVH), moderate-to-severe subaortic stenosis, a normal aortic valve, and the presence of a subaortic membrane (Figure E1, A). The peak pressure gradient was 70 mm Hg, and the mean pressure gradient was 45 mm Hg. The child underwent surgical intervention for closure of the patent ductus arteriosus during the same admission and an elective operation for subaortic membrane removal at the age of 21 months. The subaortic membrane, surrounding hypertrophied muscles, and free wall were excised. Histopathology showed fibromuscular tissue fragments exhibiting secondary regenerative changes on a myxoid background. A follow-up echocardiogram showed moderate LVH, a peak pressure gradient of 51 mm Hg, and a mean pressure gradient of 32 mm Hg. PATIENT 2. A 5-year-old, otherwise healthy sister of the proband was found to have a heart murmur. Echocardiography showed the presence of a subaortic membrane (Figure E1, B), moderate aortic stenosis, and moderate LVH. The LVOT pressure gradient was 90 mm Hg, and the mean pressure gradient was 55 mm Hg. She underwent elective surgical excision of the subaortic membrane, hypertrophied muscles, and free wall. Histopathology revealed fibromuscular tissue showing spindle-shaped cells with abundant intercellular connective tissue stroma. Postoperative echocardiography showed moderate aortic valvular stenosis and a peak pressure gradient of 72 mm Hg.

Minimally invasive resection of congenital subaortic stenosis

Fifteen consecutive patients with membranous subaortic stenosis underwent resection by a minimal-access approach through a partial upper sternotomy using a cardioscope. There were no operative deaths and no postoperative complications. Twelve patients (80%) were extubated in the operating room. The mean hospital stay was 3.1 days, and 3 patients (20%) needed blood products. Our experience demonstrates that this modified approach is a safe and effective surgical option for resection of subaortic stenosis.

Membranous Subaortic Stenosis Presenting Decades After Surgical Correction for Tetralogy of Fallot

Subaortic stenosis is rare in the middle-aged adult. Its association with tetralogy of Fallot is extremely rare. We report two middle-aged patients, presenting three decades after surgical repair of tetralogy of Fallot, with the rare association of subaortic stenosis. The clinical presentation in each patient mimicked residual pulmonary stenosis and insufficiency, but echocardiography revealed subaortic stenosis with associated valvular aortic regurgitation. (J Am Soc Echocardiogr 1998;11;206–8.)

Discrete Membranous Subaortic Stenosis: Improved Results After Resection and Myectomy

Background. Despite an adequate resection, a significant recurrence rate is encountered in patients undergoing operation for discrete membranous subaortic stenosis. The fibrous membrane and hypertrophied myocardium commonly are removed, but because of the involved risks, the resection may be inadequate and contribute to the recurrence rate. Methods. A review of the cases of 23 patients undergoing operation for discrete membranous subaortic stenosis from 1980 to 1994 was undertaken. Fourteen patients (61%) had coexisting cardiac lesions, all of which were concomitantly repaired. Results. The left ventricle–aorta gradient decreased from a preoperative mean of 63.39 ± 7.63 mm Hg to 15.17 ± 3.06 mm Hg postoperatively ( p < .001) during a mean follow-up of 3.32 ± 0.58 years. Aortic insufficiency decreased postoperatively in 8 patients (34.8%), remained unchanged in 6 patients (26.1%), and showed only insignificant progression in 4 patients (17.4%). There were no early deaths, and the single late death was not cardiac related. No patient had development of endocarditis or heart block or required a pacemaker. One patient (4.3%) had a recurrence, which required reoperation. Conclusions. Our results suggest that aggressive myectomy in concert with membrane resection constitutes safe treatment for discrete membranous subaortic stenosis and is associated with low rates of endocarditis, recurrence, and progression of aortic insufficiency.

Video-Assisted Resection of Hypertrophied and Fibrous Intraventricular Tissue

There is increasing interest in endoscopic techniques in cardiac surgery. However, use of the endoscope during open heart operations is still not routine. Cardioscopy has been used in patients with hypertrophied obstructive cardiomyopathy, asymmetric septal hypertrophy, or membranous subaortic stenosis. We demonstrate the resection of this pathologic tissue under direct visualization. With this technique we could increase the safety and accuracy of this surgical procedure. Beside this advantage, the entire operating room staff could follow the surgical intervention, which increases its educational side-effect.(Ann Thorac Surg 1997;63:1180–2)

Surgery for membranous subaortic stenosis. Long-term follow-up

Journal Article Surgery for membranous subaortic stenosis. Long-term follow-up Get access European Journal of Cardio-Thoracic Surgery, Volume 8, Issue 2, February 1994, Pages 110–112, https://doi.org/10.1016/1010-7940(94)90105-8 Published: 01 February 1994

The probability of detecting a subaortic ridge in children with ventricular septal defect or coarctation of the aorta

Membranous subaortic stenosis can be found as an isolated congenital defect or in association with other congenital heart lesions such as ventricular septal defect (VSD) 1–7 or coarctation of the aorta (C of A). 8 Recent reports have suggested an increased incidence of membranous subaortic stenosis in patients with VSD and right ventricular muscle bundles, 9 malalignment VSD 10 and ventricular septal aneurysm. 11–14 Membranous subaortic stenosis develops and progresses over time 15–17 and usually requires surgery. Subaortic stenosis is often associated with damage and thickening of the aortic valve, leading to aortic valve regurgitation. 18–20 In patients with VSD, ventricular septal aneurysm or C of A, we have observed an echogenic ridge of tissue in the left ventricular outflow tract that may be a precursor to membranous subaortic stenosis. To determine the probability of detecting a subaortic ridge in patients with VSD in different locations and in patients with C of A, and to determine if ventricular septal aneurysm increases the probability of detecting a subaortic ridge in patients with perimembranous VSD, we reviewed the echocardiographic records of our patients with VSD, subaortic ridge or C of A.

Surgery for Discrete Subvalvular Aortic Stenosis: Actuarial Survival, Hemodynamic Results, and Acquired Aortic Regurgitation

Discrete membranous subaortic stenosis (DMSS) accounts for 8 to 30% of congenital left ventricular outflow obstruction. The immediate effectiveness of surgical resection of this discrete obstructing membrane has been well documented, but little has appeared regarding late clinical and hemodynamic follow-up. Fifty-three patients with DMSS underwent operation at our institution from 1957 to 1983. Most (78%) were symptomatic, 79% had left ventricular hypertrophy (LVH) by electrocardiogram, and 92% had roentgenographic evidence of cardiomegaly preoperatively. Catheterization revealed a mean preoperative left ventricular-aortic gradient of 89 mm Hg. Twenty-eight patients had associated aortic insufficiency (AI) on the initial aortogram. Seven patients acquired AI in the interim between the first and second preoperative catheterization. Our patients have been followed for up to 12 years postoperatively. There have been 2 early and 3 late deaths. (Actuarial analysis revealed 5- and 10-year survival of 95% and 83%, respectively.) Seventy-one percent of the previously symptomatic patients noted relief of their preoperative complaints, and 45% of those with LVH had a regression in voltage. Cardiomegaly as determined by chest roentgenogram decreased in 45%. The left ventricular-aortic gradient fell to an average of 35 mm Hg a year postoperatively. Surgical treatment of congenital subvalvular aortic stenosis is effective in reducing the preoperative symptoms and the left ventricular-aortic gradient. It appears that DMSS causes AI.

Familial membranous subaortic stenosis.

Familial occurrence of membranous subaortic stenosis (MSS) is described in three families. The defect was found in 2 siblings in two of these families, and in 3 siblings of the third family. The importance of early diagnosis and treatment of MSS is emphasized. We suggest early evaluation of first-degree relatives of patients with MSS for the possibility of this defect.

Echocardiographic Diagnosis of a Discrete Membranous Subaortic Stenosis with Aneurysm of the Membrane: A Hitherto Undescribed Entity

A case of echocardiographically-demonstrated congenital aneurysm of the subaortic membrane, confirmed at surgery, is presented. The echocardiographic pattern may create an impression of vegetations of bacterial endocarditis. We were not able to find a similar case in the literature.