Surgical pathology of subaortic septal myectomy: histology skips over clinical diagnosis.

BACKGROUND: Subaortic septal myectomy is usually performed to mitigate obstruction in patients with the obstructive form of hypertrophic cardiomyopathy (HCM) or in those with congenital subaortic stenosis. Moreover, it is combined with aortic valve replacement in patients with severe aortic valve stenosis (SAS) and asymmetrical septal hypertrophy causing concomitant left ventricular outflow tract obstruction. When both conditions coexist, it is conceptually difficult to identify a cardiomyopathy beyond an adaptive myocardial hypertrophy, strictly related to pressure overload. Myectomy histopathology might be useful to enlighten the cause of the obstruction and establish the diagnosis. AIM: The aim was to describe the pathological findings of surgical septal myectomy specimens obtained from a group of patients with diverse clinical diagnosis, including HCM, severe aortic stenosis, and asymmetrical septal hypertrophy. METHODS: This was a retrospective study of 56 patients undergoing septal myectomy along a 10-year period at a tertiary cardiac surgical center. Clinical, interventional, and anatomopathological findings between patients with and without a preoperative diagnosis of HCM were analyzed and compared. RESULTS: Mean age at intervention was 67.5±20.5 years; 37 (66.1%) were female Preoperative diagnosis of sarcomeric obstructive HCM was assumed in 23 (41.1%) patients. All the other patients (58.9%) were referred for surgery with preoperative diagnosis of asymmetric septal hypertrophy, mainly in the context of severe aortic stenosis (24 patients). Twenty-seven (48.2%) patients had a greater than 30 mmHg intraventricular gradient at rest. Patients with presumed HCM were significantly younger (56.5±15.8 vs. 70.2±13.3 years, P<.001), had higher prevalence of significant intraventricular obstruction at rest [20 (87.0%) vs. 8 (34.8%), P<.001], and more frequently had moderate or severe mitral regurgitation [9 (39.1%) vs. 5(15.1%), P=.043]. All patients with aortic valve stenosis underwent both aortic valve replacement and septal myectomy. Twelve (52.1%) of the patients with obstructive HCM had isolated septal myectomy, while in the remaining 11, the procedure was combined with intervention on the mitral valve. Histopathological final diagnosis was of nonspecific reactive myocardial hypertrophy in all but 4 (92.2%) patients. In those, 2 (3.6%) had the final diagnosis of HCM and 2 (3.6%) the diagnosis of congenital subaortic membranous stenosis with reactive myocardial hypertrophy. Different grades of subendocardial fibroelastosis and myocardial fibrosis, mainly interstitial, were present [27 (48.2%) and 18 (32%) patients, respectively]. When microscopic data were compared between patients with or without a preoperative clinical diagnosis of HCM, no significant differences were found. CONCLUSION: In patients submitted to surgical septal myectomy, histology was mostly indistinctive among different clinical entities. Since different myocardial hypertrophy etiologies may share similar pathological expression, there is a need for detailed clinical assessment when trying to define the best strategy for clinical management.

Subaortic membrane and aorto-septal angle: an echocardiographic assessment and surgical outcome.

BACKGROUND: Development of a subaortic membrane is not fully understood. Recurrence after surgical removal continues to be high. We sought to assess the differences in aorto-septal angles (AoSA) to possibly explain alterations within the left ventricular outflow tract, hence in subaortic membrane formation. METHODS: A total of 113 patients who underwent subaortic membrane resection were matched by age and sex with 113 controls. The subaortic membrane resection group included isolated subaortic membranes (n = 34, group I), associated with ventricular septal defect (n = 29, group II), or patent ductus arteriosus (n = 50, group III). RESULTS: Mean (± standard deviation) AoSA (in degrees) were not different between subaortic membrane groups I, II, and III but were steeper than their control groups (126.2 ± 9.2 vs 138.6 ± 7.0, 129.2 ± 9.9 vs 137.7 ± 10.0, and 126.2 ± 8.1 vs 135 ± 8.5, respectively; all Ps < .05). Additionally, group II had lower preoperative gradients (28.8 ± 20.7 mm Hg) compared to groups I and III (67.0 ± 32.9 and 66.2 ± 33.1 mm Hg, respectively, P < .001). Follow-up ranged from 3 to 132 months. In 22 (32%) patients, a subaortic membrane recurred. Early postoperative residual gradients and development of aortic regurgutation were associated with the need for reoperation (P < .05). CONCLUSIONS: These findings suggest a contributing role of the AoSA in the development of subaortic membrane. Further rheological experiments are warranted. Whether the steeper the angle the higher the risk of recurrence may be revealed by longer follow-up periods.

Outcome of surgery for sinus of Valsalva aneurysm with discrete membranous subaortic stenosis.

BACKGROUND: Sinus of Valsalva aneurysm (SVA) is a rare cardiac anomaly, and SVA with discrete membranous subaortic stenosis is even rarer. The aim of the study was to make sure the incidence of SVA with discrete membraneous subaortic stenosis in SVA and their surgical results. We retrospectively analyzed 234 patients receiving surgical repair of SVA and reported the incidence of ventricular septal defect, aortic regurgitation, and discrete membranous subaortic stenosis. We also reported seven cases of SVA combined with discrete membranous subaortic stenosis and their surgical results. METHODS: Between January 1999 and December 2009, seven patients of SVA with discrete membranous subaortic stenosis underwent surgical repair of SVA and resection of subaortic discrete membrane. There were six male and one female patients. The mean age was (33.71 ± 13.25) years (range 16 - 52 years). Associated cardiovascular lesions were aortic regurgitation (n = 7), ventricular septal defect (n = 5), coarctation of aorta (n = 1), bicuspid aortic valve (n = 1), patent ductus arteriosus (n = 1), and aortic valve stenosis (n = 1). The aortic valve was replaced in four patients and valvuloplasty was done in three. The other co-existing anomalies were corrected at the same time. All the seven patients were followed up from 18 to 125 months (mean (63.14 ± 39.54) months). Among 234 SVA patients who underwent surgical repair, the number of cases with coexisting ventricular septal defect, aortic regurgitation, and discrete membranous subaortic stenosis was 129, 108, and 7, respectively. RESULTS: There was neither early death after operation nor late death during the follow-up period. All the seven patients were in the New York Heart Association (NYHA) functional classes I and II. There was no recurrence of discrete subaortic membrane during the follow-up period. The incidence of ventricular septal defect, aortic valve incompetence, and discrete membranous subaortic stenosis among 234 SVA patients was 55.13%, 46.15%, and 2.99%, respectively. CONCLUSIONS: Surgical repair of SVA with discrete membranous subaortic stenosis showed good mid-term results. Resection of discrete subaortic membrane should be done actively while repairing SVAs. Long-term results need to be followed up.

Valvular aortic stenosis as a major sequelae in patients with pre-existing subaortic stenosis changing spectrum of outcomes.

OBJECTIVES: The purpose of this study was to determine the prevalence of valvular aortic stenosis requiring surgery in patients with a pre-existing diagnosis of subaortic stenosis. BACKGROUND: Classic teachings emphasize aortic regurgitation as the most common complication associated with discrete subaortic stenosis. We hypothesized that significant aortic stenosis may also be an important valve lesion associated with this condition. METHODS: Clinical outcomes in patients with subaortic stenosis were examined. The primary outcome of interest was the prevalence of valvular aortic stenosis requiring surgery (surgical valvotomy or valve replacement). Logistic regression was used to identify variables associated with the need for surgery for aortic stenosis. RESULTS: One hundred twenty-one adults with subaortic stenosis (median age 32 years) were evaluated in our clinic. Associated lesions were common: 23% had bicuspid valves and 21% had coarctation of the aorta. Seventy-nine percent of the patients had at least 1 surgical resection of subaortic tissue (median age 12 years). Moderate to severe aortic regurgitation was present in 16% of patients (19 of 121), 3 of whom required surgical intervention in adulthood. Twenty-six percent of patients (32 of 121) required surgery for valvular aortic stenosis. Valve surgery for aortic stenosis was more common in patients with concomitant bicuspid aortic valve disease (p = 0.008), coarctation of the aorta (p = 0.03), and supravalvular stenosis (p = 0.02). CONCLUSIONS: Valvular aortic stenosis is a surprisingly common finding in patients with discrete subaortic stenosis. Careful clinical follow-up of this population to monitor aortic valve status continues to be warranted even after a successful surgical resection.

Takedown of Yasui procedure due to closed ventricular septal defect.

A two and a half year old girl who had undergone the Yasui procedure as a neonate for ventricular septal defect, subaortic stenosis, and interrupted aortic arch underwent follow-up catheterization 2 years postoperatively. It showed that the neo-left ventricular tract reconstructed by Damus-Kaye-Stansel anastomosis had occluded due to closure of the ventricular septal defect and residual subaortic stenosis at the original left ventricular outflow tract. The patient therefore underwent takedown of the Yasui procedure.

Discrete subaortic membranes in adults--a clinicopathological analysis.

INTRODUCTION: A discrete subaortic membrane (DSM) is one of the causes of subaortic stenosis in children. The incidence, characteristics, and the therapeutic options for such membranes in adults have not been well documented. This report documents the clinical and pathological features of DSM in adults. METHODS: DSMs, surgically excised over a 10-year period in a large adult tertiary care center, were reviewed with regard to the age and gender of the patients, clinical findings, and the morphological features. RESULTS: Among the 19 adults, there were six males and 13 females, with age ranging from 26 to 75 years. The patients most often presented with dyspnea, fatigability, and palpitation for 3 months to 2 years. Four patients (21%) had other congenital heart disease in association with the DSM; in the rest, the membranes were isolated occurrences (79%). A cardiac murmur or the presence of membranes had been noted in childhood in four patients. Tissue growths over the ventricular surface of the anterior mitral leaflet were seen in 18 cases. Irrespective of the gross appearance, the stenosing lesions exhibited five tissue layers, beginning from the luminal aspect, endothelium, acid mucopolysaccharide-rich subendothelial layer, collagen-rich fibrous layer, fibroelastotic layer, and a smooth muscle layer. Twelve patients (63%) had aortic regurgitation, which necessitated repair or replacement in seven. Septal myectomy resulted in conduction abnormalities in nine. CONCLUSIONS: The study describes the occurrence of DSM in adults. It is important to remember that it can occur following a repair of underlying congenital heart disease.

Multiplanar review analysis of three-dimensional echocardiographic datasets gives new insights into the morphology of subaortic stenosis.

AIMS: Associated left ventricular structures may play a role in progression and recurrence of discrete subaortic stenosis. The availability of a new 3D echocardiography tool, multiplanar review (MPR), allows comprehensive analysis of datasets in infinite planes, and detailed examination of anatomy. We sought to evaluate the role of MPR in defining the morphology of subaortic stenosis. METHODS: Consecutive patients underwent detailed 2 and 3D echocardiographic examination using MPR. RESULTS: Sixteen patients aged 0.7-15.9 years (median 4.57) with diagnosis as follows: isolated subaortic stenosis in nine, additional defects in seven (coarctation of aorta, VSD, mitral, or aortic stenosis). Position and extent of subaortic stenosis was clearly described by multiplanar review in all patients. Additional MPR findings were: abnormalities of mitral valve leaflet or chordal apparatus attachments (14 patients), abnormal ventricular muscle band (11), abnormal increased aorto-mitral separation (two). The aortoseptal angle was significantly decreased in subaortic stenosis, mean 141 +/- 12 degrees , vs. normal subjects, mean 153 +/- 6 degrees , P = 0.02. Surgical findings correlated well with MPR findings. CONCLUSIONS: MPR analysis of 3D datasets is a sensitive and accurate mode for delineation of morphological details of discrete subaortic stenosis, providing additional information to 2D echocardiography.

Steepened aortoseptal angle may be a risk factor for discrete subaortic stenosis in adults.

Discussion exists whether discrete subaortic stenosis (DSS) is a congenital or acquired cardiac defect. Currently, it is regarded an "acquired" cardiac defect presumably secondary to altered flow patterns due to morphological abnormalities in the left ventricular outflow tract, as have been shown by some studies in the pediatric population. In this report, we demonstrated a steepened aortoseptal angle in adults with DSS without previous cardiac surgery in comparison to controls. Our results strengthen the hypothesis that altered flow patterns due to a steepened aortoseptal angle are a substrate for development of DSS in adults.

The "1st septal unit" in hypertrophic obstructive cardiomyopathy: a newly recognized anatomo-functional entity, identified during recent alcohol septal ablation experience.

In hypertrophic obstructive cardiomyopathy, selective and asymmetric hypertrophy results in a stenotic subaortic channel, which is further narrowed by a Venturi effect (suctioning of the anterior leaflet, manifested by systolic anterior motion of the mitral valve). Better understanding of these essential pathophysiologic mechanisms has led to the definition of a new anatomo-functional entity, the 1st septal unit, which consists of the basal interventricular septal hypertrophy and its related septal arterial branches. As an alternative to surgical myomectomy, alcohol septal ablation is an effective method of reducing subaortic stenosis and improving mitral valve function. After alcohol ablation, global negative remodeling of the hypertrophied left ventricle eventually ensues. This review presents specific anatomic and functional features of a newly identified pathophysiologic entity (the 1st septal unit) in relation to the clinical manifestations and natural history of hypertrophic obstructive cardiomyopathy. This relationship is also relevant during the performance of alcohol septal ablation interventions: related operative suggestions are provided for optimizing subaortic stenosis relief during septal ablation and for preventing complications.

Geometry of the left ventricular outflow tract in fixed subaortic stenosis and intact ventricular septum: an echocardiographic study in children and adults.

OBJECTIVE: We compared the echocardiographic geometry of the preoperative and postoperative left ventricular outflow tract in children and adults with isolated fixed subaortic stenosis with age- and weight-matched controls to elucidate whether the geometry can be modified when surgical intervention is performed at a younger age. METHODS: The mitral-aortic valve distance, aortic valve diameter, aorto-left ventricular septal angle, degree of aortic valve dextroposition, aortic valve-subaortic stenosis distance, width of left ventricular outflow tract, left ventricle wall thickness, and septal thickness were determined preoperatively and postoperatively in 21 patients and 21 controls. The measurements were indexed to body surface area. Patients were divided into 3 age groups: group 1 comprised 9 patients aged 1 to 10 years, group 2 comprised 8 patients aged 11 to 20 years, and group 3 comprised 4 patients aged 21 years or more. RESULTS: Compared with controls, patients had a significantly wider mitral-aortic separation (group 1, P = .003; group 2, P = .02), a steeper aortoseptal angle (group 1, P = .02; group 3, P = .03), a smaller left ventricular outflow tract width (group 1, P = .003; group 2, P = .01), a marked aortic valve dextroposition (groups 1 and 3), an increased left ventricle wall thickness (group 1, P = .03), and an increased septal thickness (group 1, P = .01). There was a significant difference between preoperative and postoperative values in aortoseptal angle and left ventricular outflow tract width in patients up to 10 years of age (P = .02 and P = .01, respectively). CONCLUSIONS: Hearts with isolated subaortic stenosis have abnormal left ventricular outflow tract geometry that postoperatively showed changes in left ventricular outflow tract width and aortoseptal angle. Compared with controls, the aortoseptal angle does not "normalize" when surgery is performed in older patients, suggesting that left ventricular outflow tract geometry may be remodeled in younger patients.

Discrete subaortic stenosis in adults: increased prevalence and slow rate of progression of the obstruction and aortic regurgitation.

OBJECTIVES: We sought to determine the prevalence and rate of progression of left ventricular outflow tract obstruction (LVOTO) and aortic regurgitation (AR) in adults with discrete subaortic stenosis (DSS). BACKGROUND: Discrete subaortic stenosis is an uncommon form of LVOTO, with rapid hemodynamic progression in children, but the prevalence and rate of progression in adults have not been studied so far. METHODS: The prevalence of DSS was determined in 2,057 consecutive adults diagnosed with congenital heart disease (CHD). The relationship between LVOTO on Doppler echocardiography and patient age was analyzed. Sequential changes in LVOTO and AR were determined for patients with two or more Doppler echocardiograms obtained with at least a two-year interval. RESULTS: A total of 134 adults (mean age 31 +/- 17 years) were diagnosed with DSS. The prevalence was 6.5% for all adults with CHD. Sixty patients (44%) had other associated CHD. The mean age of 29 patients who had undergone an operation for DSS during their adult life (56 +/- 15 years) was significantly higher than that of 64 patients (27 +/- 13 years) who had not required a surgical intervention (p < 0.0001). A significant relationship between LVOTO and patient age (r = 0.61, p < 0.0001) was found: 21 +/- 16 mm Hg in patients <25 years old, 51 +/- 47 mm Hg for those between 25 and 50 years old, and 78 +/- 36 mm Hg for those >50 years old. The LVOTO increased from 39.2 +/- 28 to 46.8 +/- 34 mm Hg (p = 0.01) during a mean follow-up of 4.8 +/- 1.8 years in 25 patients. The slope of the change in LVOTO was 2.25 +/- 4.7 mm Hg per year of follow-up. Aortic regurgitation was detected by color Doppler imaging in 109 patients (81%), but it was hemodynamically significant in <20%. An increase in the mean degree of AR over time was not significant (baseline: 1.3 +/- 0.8; follow-up: 1.5 +/- 0.9; p = 0.096). CONCLUSIONS: The prevalence of DSS is increasing in adults due to the greater number of repaired CHDs that develop into evolutive DSS. In contrast to infants and children, adults with DSS show a slow rate of LVOTO progression. Aortic regurgitation is a common but usually mild and nonprogressive consequence. The current indications for surgical intervention should be revised.

Palliated congenital heart disease.

The group of patients with palliated complex forms of congenital heart disease presents a challenging and difficult management problem during the adolescent years. In patients not considered to be candidates for more fully palliated procedures that separate the circulations, a bidirectional caval pulmonary shunt, often associated with a systemic to pulmonary shunt, may provide significant palliation for several more decades. However, there remain a significant number of patients who, after some years, may develop increasing problems associated with myocardial failure and the development of serious atrial arrhythmias. Interventional cardiac catheterization combined with newer surgical techniques may return many of these patients to more satisfactory hemodynamic states. However, some patients during their adolescent years may eventually require cardiac transplantation for the long-term management of their complex congenital cardiac defects.