Computed Tomographic Evaluation of Congenital Left Ventricular Outflow Obstruction.

Congenital left ventricular outflow obstruction represents a multilevel obstruction with several morphological forms. It can involve the subvalvular, valvar, or supravalvular portion of the aortic valve complex, and may coexist. Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital LVOT obstruction. Unlike transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging, it is not bounded by a small acoustic window, needs for anaesthesia or sedation, and metallic devices. Current generations of CT scanners with excellent spatial and temporal resolution, high pitch scanning, wide detector system, dose reduction algorithms, and advanced 3-dimensional postprocessing techniques provide a high-quality alternative to CMR or diagnostic cardiac catheterization. Radiologists performing CT in young children should be familiar with the advantages and disadvantages of CT and with the typical morphological imaging features of congenital left ventricular outflow obstruction.

Right ventricular outflow tract obstruction: a quest for ideal management.

Management of right ventricular outflow tract obstruction has undergone much change over the last century. Techniques described in the literature include anatomical repairs and the use of various patches, conduits, and innovative grafts. However, many of these approaches require reoperations or catheter-based interventions, leading to increased morbidity, mortality, and cost. The search for the ideal long-lasting conduit continues and there are new techniques on the horizon, using genetic engineering and nanotechnology. This review discusses the evolution of various techniques for repair of right ventricular outflow tract obstruction, past and current conduits, as well as ongoing research.

The Damus-Kaye-Stansel 0peration: Management of systemic ventricular outflow tract obstruction.

The Damus-Kaye-Stansel (DKS) anastomosis was originally described for the treatment of transposition of the great arteries but it is now used mainly for the treatment of single ventricle anomalies in patients who are at risk of developing systemic ventricular outflow tract obstruction (SVOTO). In most instances, DKS is performed as a concomitant procedure at time of bidirectional cavopulmonary connection in these patients. This tutorial we demonstrate our modified double-barrel approach, along with anterior patch augmentation of the distal ascending aorta. We have found that this technique is very effective in mitigating SVOTO risk while preserving semilunar valve anatomy and function.

Ross-Konno Procedure With Cylinder Mitral Valve Replacement in 49 Days Old Infant.

A neonate with antenatally diagnosed severe aortic valve stenosis, left ventricular outflow tract obstruction, left ventricular endocardial fibroelastosis, and severe mixed mitral valve disease was admitted to our center for balloon aortic valvuloplasty. On day 49, we performed a Ross-Konno procedure and mitral valve replacement on the baby, whose weight was 3.4 kg. Right ventricle-to-pulmonary artery continuity was restored with a handmade trileaflet Gore-Tex conduit. We used a handmade cylindrical prosthesis made from decellularized equine pericardium in the mitral position. We observed improvement in left ventricular function and good performance of aortic, pulmonary, and mitral prostheses at four months of follow-up.

Midterm results of the Ross procedure in children: an appraisal of the subannular implantation with interrupted sutures technique.

OBJECTIVES: The support of the pulmonary autograft root by the fibromuscular left ventricular outflow tract is emphasized to address the concern related to the dilatation of the pulmonary autograft structures in the paediatric population. METHODS: This retrospective study analyses the outcomes of 75 children who were operated between 1998 and 2012 with the subannular interrupted sutures technique at a median age of 10.2 years (range, 5.3 months-18.0 years). Median follow-up time was 5.2 years (range, 3 days-13.2 years). RESULTS: There were no deaths, but there were 3 reinterventions on the autograft for regurgitation and 2 resections of left ventricular outflow tract obstruction. There was no significant autograft stenosis, and freedom from moderate-to-severe regurgitation was 95% (95% confidence interval: 89-100) and 88% (95% confidence interval: 77-99) at 5 and 10 years, respectively. Median z-scores at the latest follow-up examination were, at the annulus, 0.31 [interquartile range (IQR) = -0.81 to 1.2]; at the sinus of Valsalva, 2.7 (IQR = 1.5-3.5); and at the sinotubular junction, 3.1 (IQR = 1.7-4.2). The correlation between z-scores and time after the operation was negative at the level of the annulus (r = -0.29, P = 0.034) but positive at the level of the sinus (r = +0.37, P = 0.005) and the sinotubular junction (r = +0.26, P = 0.068). The median rate of change in the z-score at the annulus was low, 0.065 z-score/year (IQR = -0.13 to 0.43). CONCLUSIONS: The subannular interrupted sutures implantation technique is associated with acceptable risks and, in the midterm, delivers limited annular dilatation, autograft regurgitation and delayed need for autograft reintervention.

Asymptomatic and isolated accessory mitral valve tissue in an adult.

Accessory mitral valve (AMV) tissue is a congenital anomaly that occurs in association with other congenital anomalies, and is an uncommon cause of left ventricular outflow tract obstruction. It is usually detected in early childhood when accompanied by symptoms of obstruction of the left ventricular outflow tract, and is rarely diagnosed in adults. We present a case of a 53-year-old man who was referred to our institution for evaluation of a systolic heart murmur. Echocardiography disclosed a diagnosis of AMV tissue. This case was uncommon because of the lack of severe obstruction of left ventricular outflow, cardiac symptoms, or other cardiac anomalies. We were able to carry out surgical resection of AMV tissue to avert possible progression of aortic insufficiency and the risk of a cerebrovascular embolization. The patient's postoperative course was uneventful, and postoperative echocardiography showed no residual accessory mitral tissue.

Ross Procedure in Neonates and Infants: A European Multicenter Experience.

BACKGROUND: Infants and neonates with severe left ventricular outflow tract obstruction may require pulmonary autograft replacement of the aortic root. In this retrospective multicenter cohort study, we present our experience with the Ross procedure in neonates and infants with a focus on midterm survival and pulmonary autograft durability. METHODS: A retrospective observational study was performed in 76 infants (aged less than 1 year) operated on in six congenital cardiac centers in The Netherlands and Germany between 1990 and 2013. RESULTS: Patients had a pulmonary autograft replacement of the aortic valve with (68%) or without (32%) septal myectomy. Median patient age was 85 days (range, 6 to 347). Early mortality (n = 13, 17%) was associated with neonatal age, preoperative use of intravenous inotropic drugs, and congenital aortic arch defects. Five patients (9%) died during follow-up. Freedom from autograft reintervention was 98% at 10 years. Echocardiography demonstrated good valve function, with no or trace regurgitation in 73% of patients. Freedom from right ventricular outflow tract reintervention was 51% at 10 years. Univariable analysis demonstrated superior freedom from reintervention of pulmonary homografts compared with aortic homografts or xenografts. CONCLUSIONS: Pulmonary autograft replacement of the aortic valve in neonates and infants is a high-risk operation but offers a durable neoaortic valve. Midterm durability reflects successful adaptation of the autograft to the systemic circulation. Late mortality associated with heart failure was an unexpected finding.

[Discrete Subaortic Stenosis in an Adult; Report of a Case].

Discrete subaortic stenosis (DSS) is a well-described cause of isolated left ventricular outflow tract obstruction( LVOTO) in children. But prevalence, rate of progression and postoperative data in adults are limited. We report a case of a 30-year-old woman, who was referred to our institution because of chest pain and loss of consciousness. Echocardiography revealed DSS with LVOTO (peak gradient 81 mmHg) and mild aortic regurgitation. Increased age at the time of diagnosis, female sex and preoperative left ventricular outflow tract(LVOT) gradient ≥80 mmHg were thought to be predictors for reoperation, therefore the obstructing membrane was circumferentially excised and concomitant localized myectomy of the ventricular septum was performed to achieve complete relief of the LVOT obstruction. Her postoperative course was uneventful, and she was discharged on the 5th postoperative day.

Stenting of Native Right Ventricular Outflow Tract Obstructions in Symptomatic Infants.

OBJECTIVE: To assess feasibility, safety and effectiveness of right ventricular outflow tract (RVOT) stenting in symptomatic young infants. METHODS: Multicentre evaluation of 35 patients intended to undergo RVOT stenting in 11 pediatric cardiac centres from 2009 to August 2011. RESULTS: Median age and weight at the time of first stent implantation were 8 weeks and 3.3 kg, with 40% of patients <3 kg. A total of 19 patients had suffered from hypoxemic spells, 8 patients were ventilated, 6 on inotropic support and 5 on prostaglandin infusion. Severe concomitant malformations were present in 11 patients, and acute infections in 2. Stenting of the RVOT was successfully performed in 33 patients, improving oxygen saturation from a median of 77 to 90% 2 days after intervention. Besides the 2 patients in whom RVOT stenting was not successful for technical reasons, there were no procedural complications. In 17 of 33 patients, 1-3 reinterventions were performed during follow-up, less than half of those were reinterventions in the RVOT. A total of 27 patients have undergone successful surgical repair 4-162 (median 19.5) weeks after initial RVOT stent implantation, 2 patients are still waiting. There were no perioperative deaths. CONCLUSIONS: Stenting of the RVOT provides a safe and effective management strategy for initial palliation in symptomatic young infants, including those patients not suitable or at higher risk for surgical therapy.

Isolated right subclavian artery with interrupted aortic arch, ventricular septal defect, and left ventricular outflow tract obstruction.

We present two cases of isolated right subclavian artery from the right pulmonary artery (PA) associated with interrupted aortic arch, ventricular septal defect, left ventricular outflow tract obstruction, and 22q11 microdeletion. Both patients were successfully managed with bilateral PA banding initially followed by a modified Yasui operation. Isolation of the subclavian artery is rare but should always be taken into account, especially when bilateral PA banding is considered. The banding must then be placed on the PA distal to the origin of the subclavian artery.

Echocardiographic evaluation of congenital left ventricular outflow obstruction.

Left ventricular outflow obstructions (LVOTO) encompass a series of stenotic lesions beginning within the anatomic left ventricular outflow tract and ending in the descending thoracic aorta, occurring alone or in series. The degree of stenosis and hemodynamic consequences may vary from mild and well tolerated to severe and functionally limiting. The majority of LVOTO (with the exception of calcific and rheumatic aortic stenosis) are congenital in etiology. Echocardiography has become an integral tool in the assessment of patients with congenital heart disease. This article is a contemporary review of the clinical features of LVOTO and the role of echocardiography in this patient population.

Risk factors in the origin of congenital left-ventricular outflow-tract obstruction defects of the heart: a population-based case-control study.

The aim of our project was to study possible etiological factors in the origin of congenital heart defects (CHDs) because in the majority of patients the underlying causes are unclear. Cases with different CHD entities as homogeneously as possible were planned for evaluation in the population-based large data set of the Hungarian Case Control Surveillance of Congenital Abnormalities. Dead or surgically corrected 302 live-born cases with different types of left-ventricular outflow tract obstructive defects (LVOT, i.e., valvular aortic stenosis 76, hypoplastic left heart syndrome 76, coarctation of the aorta 113, and other congenital anomalies of aorta 32) were compared with 469 matched controls, 38,151 controls without any defects, and 20,750 malformed controls with other isolated defects. Medically recorded pregnancy complications and chronic diseases were evaluated based on prenatal maternity logbooks, whereas acute diseases, drug treatments, and folic acid/multivitamin supplementation were analyzed both on the basis of retrospective maternal information and medical records. The results of the study showed the role of maternal diabetes in the origin of LVOT in general, while panic disorder was associated with a higher risk of hypoplastic left heart syndrome and ampicillin treatment with a higher risk of coarctation of the aorta (COA). High doses of folic acid had a protective effect regarding the manifestation of LVOT, particularly COA. In conclusion, only a minor portion of causes was shown in our study; thus, further studies are needed to understand better the underlying causal factors in the origin of LVOT.

Outcomes of the modified norwood procedure: hypoplastic left heart syndrome versus other single-ventricle malformations.

Recent studies have suggested that survival after the modified Norwood procedure is influenced by anatomy and is worse for patients with hypoplastic left heart syndrome (HLHS) than for patients with other forms of functional single ventricle. This study aimed to compare the outcomes of the modified Norwood procedure for these two groups at a single center. A retrospective chart review compared modified Norwood procedure outcomes between children with HLHS (n = 40) and children with other single-ventricle malformations (n = 19) from January 2002 to August 2012. The HLHS patients had a lower mean age (10.0 ± 13.2 days) at the time of operation than the non-HLHS patients (16.5 ± 18.5 days). The difference was not significant. The number of patients with a Sano modification was significantly higher in the HLHS group (HLHS 85 % vs non-HLHS 32 %; p < 0.001). The follow-up data did not differ between the groups (HLHS 3.6 ± 3.2 years vs non-HLHS 4.8 ± 3.3 years, nonsignificant difference). The overall operative survival was 85 %: 83 % for the patients with HLHS and 89 % for the patients with non-HLHS (nonsignificant difference). The Kaplan-Meier transplant-free survival estimate at 10 years was 73 % and did not differ between the HLHS patients (67 %) and the non-HLHS patients (84 %, nonsignificant difference). The timing of stages 2 and 3 palliation (bidirectional Glenn and external conduit Fontan) did not differ significantly (HLHS, 7.0 ± 2.8 months and 3.0 ± 0.5 years vs non-HLHS 6.1 ± 1.7 months and 2.8 ± 0.8 years). The two groups were similar with respect to the need for post-Norwood extracorporeal membrane oxygenation support, aortic arch reinterventions, atrioventricular valve repair, pulmonary artery reconstruction, pacemaker implantation, and progression to bidirectional Glenn and Fontan completion. The modified Norwood reconstruction provides good palliation for HLHS as well as other forms of functional single-ventricle anatomy. Survival, postoperative morbidity, and progression to Glenn and Fontan are not significantly different.

The Ross, Konno, and Ross-Konno operations for congenital left ventricular outflow tract abnormalities.

Operations for left ventricular outflow tract abnormalities are centred on hemodynamic conditions that relate to subvalvar stenosis, valvar stenosis/regurgitation, aortic annular hypoplasia, and supravalvar aortic stenosis. Operative interventions over the years have evolved because the intervening outcomes proved to be unsatisfactory. The resection for subvalvar aortic stenosis has progressed from a fibrous "membrane" resection to a more extensive fibromuscular resection. Operative solutions for valvar aortic stenosis and regurgitation have resulted in operative interventions that depend on simple commissurotomy, leaflet extensions, prosthetic mechanical valve replacement, biologic valve replacement, including the pulmonary autograft, and operations to treat aortic annular stenosis. Although there are enthusiastic proponents for all of these strategies, the fact remains that none have proven to be curative; patients can expect to undergo further procedures during their lifetimes. The short- and mid-term solutions to these left ventricular outflow tract abnormalities have improved based on operations that have been attended by increasing operative complexity. The purpose of this review is to chronicle the operative steps of the Ross operation, the Konno-Rastan operation, the modified Konno operation, the Ross-Konno operation, and the modified Ross-Konno operation.

Porcine bioprosthetic valve in the pulmonary position: mid-term results in the right ventricular outflow tract reconstruction.

Pulmonary valve replacement (PVR) for pulmonary valve insufficiency (PVI) currently represents the most frequent reoperation performed for adults with congenital heart disease. A variety of pulmonary valve substitutes have been used, but none has proved to be ideal. This report reviews the authors' experience using a porcine prosthetic valve in the pulmonary position. Between January 2001 and December 2011, 76 patients (mean age, 36 years; range, 18-64 years) underwent PVR for chronic PVI using a porcine bioprosthesis. All the patients had previously undergone surgery: 65 for repair of tetralogy of Fallot and 11 for pulmonary surgical valvotomy. Magnetic resonance imaging (MRI) evaluations before surgery and at the 1-year postoperative follow-up evaluation were compared. Aside from the PVR, 59 patients (59/65, 78 %) received 94 associated cardiac surgical procedures. Two hospital deaths occurred. The mean hospital stay was 13 days (range, 7-48 days). At the 1-year control MRI, pulmonary regurgitation fraction, right ventricular end diastolic volume (RVEDV), and RV/LV EDV had improved significantly. During a mean follow-up period of 52 months (range, 6-132 months), one patient died. All the patients were categorized as New York heart association (NYHA) functional class 1. No episodes of structural valve deterioration, endocarditis, or thromboembolic event were noted. Echocardiography showed trivial or no PVI in all the patients. The porcine bioprosthetic valves demonstrated excellent midterm results in the RV outflow tract reconstruction. The hemodynamic characteristics of this valve are comparable with those of homografts or valved conduits. It is easy to implant and allows for avoiding extensive dissection, especially of the pulmonary arteries.

Aortico-left ventricular tunnel: the elusive diagnosis.

We present a case of an infant prenatally diagnosed with bilateral outflow-tract obstruction and severe aortic regurgitation who underwent cardiac transplantation at 45 days of life. Aortico-left ventricular tunnel was subsequently diagnosed on pathologic examination of the explant heart. Aortico-left ventricular tunnel is a rare congenital cardiac malformation and can remain undiagnosed if the clinician has a low level of suspicion. Aortico-left ventricular tunnel should be considered in any fetus or newborn with aortic regurgitation.

Repair of left ventricular inflow tract lesions in Shone's anomaly: valve growth and long-term outcome.

BACKGROUND: The degree of involvement of left ventricular inflow tract obstruction is the predominant factor determining outcome in Shone's anomaly. In this series of patients with Shone's anomaly, we evaluated the impact of mitral valve (MV) repair strategies performed to correct the components of this anomaly on growth of the valve and long-term functional outcome in children. METHODS: In the last 25 years, 45 children, mean age 5.16 ± 5.0 years (median, 3.9; range, 2 months-16.8 years), underwent surgical correction of Shone's anomaly. Coarctation of the aorta was found in 40%, subaortic stenosis due to fibromuscular hypertrophy was found in 55%, and subvalvar membrane was found in 66% of these patients. Left ventricular inflow tract obstruction was brought about by fused commissures with dysplastic and shortened chordae in 53.3%, valve hypoplasia in 11.1%, supravalvar mitral ring in 100%, and parachute valve in 17.8 of patients%. RESULTS: Various repair strategies were performed according to the presenting morphologic characteristics in patients with either previously corrected or concomitant correction of the left-sided obstructive lesions. Mean duration of follow-up was 17.5 ± 1.5 years. Freedom from reoperation was 52.8% ± 11.8%, wherein 23 patients underwent repeated MV repair and 1 patient underwent MV replacement after failed attempts at repair. The cumulative survival rate was 70.3% ± 8.9% at 15 years. Severity and type of mitral abnormalities, left ventricular outflow tract lesions, and pulmonary hypertension are risk factors for reoperation and mortality (p < 0.05). CONCLUSIONS: Repair allowed growth of the MV. Long-term outcome of MV repair in Shone's anomaly is related to the degree that the obstructive lesions can be relieved.

Ross-Konno procedure in infants: mid-term results.

OBJECTIVES: The aim of study was to analyse the mid-term results of the Ross-Konno procedure in infants. METHODS: Between 2000 and 2011, 16 infants, including five newborns, with complex left ventricular outflow tract (LVOT) obstruction underwent the Ross-Konno procedure. Twelve patients (75%) required multiple concomitant procedures such as: mitral valve (MV) surgery (four patients), resection of endocardial fibroelastosis (EFE) and myectomy (six patients), closure of ventricular septal defect (four patients) and aortic arch reconstruction (three patients). The median age at operation was 4.2 months (from 6 to 333 days). RESULTS: There was one late death with a median follow-up of 6.2 years. Actuarial survival is 93.3% at 5 years follow-up (95% confidence interval: 61.2-99.0). Postoperatively, two patients required extracorporeal membrane oxygenation support and one MV replacement. The median length of stay in hospital was 30 days (from 11 to 77 days). At 5 years of follow-up, seven patients had no aortic regurgitation (AR) and nine patients (56%) had trivial AR with no gradient in LVOT. Freedom from mitral regurgitation (MR) ≥ moderate or MV replacement was 70%. MR was associated with either structural abnormalities of MV or with development of EFE. Freedom from redo was 81 and 53% at 1 and 5 years of follow-up. Sixty percent of patients are without medication. All patients are in sinus rhythm. CONCLUSIONS: With the technical aspects of this procedure well accomplished, the risk of surgery is minimal and functional outcome is encouraging. However, early postoperative morbidity is significant. At the mid-term follow-up, there was no residual or recurrent outflow tract obstruction and excellent function of the neoaortic valve. A high incidence of MR associated with the development of EFE and structural abnormalities of the MV is worrisome; however, concomitant MV surgery is not associated with increased mortality. In the case of the development of EFE, an early indication for operation might protect MV function. The reoperation rate is high due to early conduit failure.

The Ross-Konno procedure as reoperative treatment in a young adult with congenital aortic stenosis.

Mechanical and biological prostheses are valid options when aortic valve replacement is necessary. The Ross procedure is also an alternative solution, especially for young patients. We describe the case of a young patient with congenital aortic stenosis and bicuspid aortic valve who presented with dyspnea on exertion. An open commissurotomy was performed, and within 8 months the patient developed recurrent symptoms of severe aortic stenosis. He underwent redo sternotomy and a Ross-Konno procedure with an uneventful recovery.

Apicoaortic conduits: indications, complications, and imaging techniques.

Left ventricular apex to descending aorta conduits may be used as a last resort treatment of severe left ventricular outflow tract obstruction in cases in which alternative therapies are contraindicated. Although this technique is rarely used in current practice for congenital cases, its use in the elderly population is increasing, largely due to the expansion of this patient cohort and associated comorbidities precluding aortic valve replacement, the most common of which are a severely calcified "porcelain" aorta and/or previous coronary artery bypass grafts preventing aortic root manipulation. Diagnostic imaging is essential in the presurgical workup and subsequent follow-up of these patients, as complications of the procedure are potentially life threatening and are not rare. Several imaging modalities may be used, each with advantages and disadvantages. Both anatomic and functional assessments play a role in the comprehensive evaluation of both presurgical and postsurgical patients.