Hypoplastic Left Heart Complex Research Articles

Staged Left Ventricular Recruitment and Biventricular Conversion for Patients With Borderline Left Heart

A borderline left heart may be present in patients with hypoplastic left heart syndrome or an unbalanced atrioventricular canal defect. Traditionally, such patients have been managed either by high-risk biventricular repair in infancy or during the neonatal period, or by definitive single-ventricle palliation. In this article, we present an approach for staged left ventricular recruitment that promotes gradual rehabilitation of left heart structures and allows delay in the commitment to either a single-ventricle pathway or a biventricular pathway. The rationale, techniques, and early results are described.

左心系の低形成を合併した下心臓型総肺静脈還流異常症に対して，段階的治療を行った1例

左心系の低形成を合併した下心臓型総肺静脈還流異常症に対して，段階的治療を行った1例

Midterm Follow-Up After Biventricular Repair of the Hypoplastic Left Heart Complex

In neonates with hypoplastic left heart complex (HLHC), biventricular repair is considered superior to univentricular repair. The Z-scores of the mitral and the aortic valve annulus are primary factors for the choice of repair. Predictive cutoff values for the feasibility and optimal outcome of biventricular repair are unknown. This study assesses the growth of left side heart structures and the midterm outcome after biventricular repair with an interatrial fenestration in our HLHC population. Retrospective study of 19 HLHC patients who underwent biventricular repair in a single tertiary referral center between 2004 and 2013. The cardiac dimensions (mitral and aortic valve annulus, left ventricle inlet length, left ventricular internal diastolic dimension) were measured before and at 6, 12, 24, and 48 months after biventricular repair. The follow-up ranged from 2 to 98 months. There was no early mortality, and the midterm survival rate was 95%. One patient died of a noncardiac- and nonintervention-related cause. Seven patients (37%) required a total of 8 reinterventions because of recurring or residual obstructive lesions. After biventricular repair, the left cardiac structures grew significantly. Neonatal biventricular repair is successful and safe in HLHC patients, even with preoperative mitral and aortic valve annulus Z-scores of-4.5 and-5.5, respectively. Residual or restenosis required reintervention in 37% of our HLHC population, but was not significantly correlated with the magnitude of the preoperative Z-scores. Within the first 6 months of follow-up, the Z-scores almost normalized.

Erratum to: Development of an Echocardiographic Scoring System to Predict Biventricular Repair in Neonatal Hypoplastic Left Heart Complex

Erratum to: Development of an Echocardiographic Scoring System to Predict Biventricular Repair in Neonatal Hypoplastic Left Heart Complex

Long-term results of biventricular repair after initial Giessen hybrid approach for hypoplastic left heart variants

This article presents the long-term results of our patients with a diagnosis of hypoplastic left heart syndrome (HLHS), hypoplastic left heart complex (HLHC), and variants who received a biventricular repair following hybrid stage I with ductal stenting and bilateral pulmonary artery banding. Between June 1998 and June 2013, a total of 154 patients with hypoplastic left heart structures underwent a hybrid stage I procedure. Forty patients were definitely treated by creating a biventricular circulation. Median age and body weight of patients before hybrid stage I were 8.5 days (2-40) and 3.0 kg (1.6-3.8), respectively. The diagnoses were HLHS with mitral and aortic stenosis (n=7), HLHC (n=15), HLHC with interrupted aortic arch (n=9), critical aortic stenosis with hypoplastic aortic arch (n=4), imbalanced atrioventricular septal defect with hypoplastic aortic arch (n=2), double-outlet right ventricle with hypoplastic aortic arch (n=2), and d-transposition of the great arteries with interrupted aortic arch (n=1). Median age at the time of biventricular correction was 6.7 months (1.6-13.8). The patients were treated with direct biventricular correction, including repair of intracardiac defects (n=32), Norwood/Rastelli or Yasui (n=4), arterial switch (n=2), Rastelli (n=1), and Ross-Konno (n=1) operations with ascending aortic/aortic arch reconstruction. All patients survived hybrid stage I. Median survival after biventricular correction is 7.9 years (0.9-14.9). Overall mortality was 10% (4 patients) at 4 weeks, 5 weeks, 6 weeks, and 4 months after biventricular correction, respectively. One patient had to be switched to univentricular circulation and another patient underwent orthotopic heart transplantation 3 and 4 months after biventricular correction, respectively. The Giessen hybrid approach is an alternative to the conventional strategy to treat neonates with HLHS, HLHC, and variants. Biventricular repair after hybrid stage I is feasible and can be performed with satisfactory long-term survival.

Development of an echocardiographic scoring system to predict biventricular repair in neonatal hypoplastic left heart complex.

Neonates born with borderline left heart hypoplasia, or hypoplastic left heart complex, can undergo biventricular repair while those with severe left heart hypoplasia require single ventricle palliation. Deciding which patients are candidates for biventricular repair may be very difficult since there are no scoring systems to predict biventricular repair in these patients. The purpose of this study is to develop an echocardiographic scoring system capable of predicting successful biventricular repair in neonatal hypoplastic left heart complex. The study cohort consisted of twenty consecutive neonates with hypoplastic left heart complex presenting between 9/2008 and 5/2013. Multiple retrospective echocardiographic measurements of the right and left heart were performed. Six patients with significant LH hypoplasia (patent mitral and aortic valves, small left ventricle) who had undergone single ventricle repair were used to validate the scoring system. Seventeen patients underwent biventricular repair and three underwent single ventricle repair. A scoring system (2V-Score) was developed using the equation {[(MV4C/AVPSLA) ÷ (LV4C/RV4C)] + MPA}/BSA. Using a cutoff value of ≤ 16.2, a biventricular repair would have been predicted with a sensitivity of 1.0, specificity 1.0, positive predictive value 1.0, negative predictive value 1.0, area under the ROC curve 1.0, and the p value was 0.0004. The 2V-Score was more accurate than the Rhodes, CHSS, or Discriminant scores in retrospectively predicting biventricular repair in this cohort. The 2V-Score shows promise in being able to predict a successful biventricular repair in patients with hypoplastic left heart complex but requires prospective validation prior to widespread clinical application.

Feasibility and safety of biventricular repair in neonates with hypoplastic left heart complex.

Hypoplastic left heart syndrome is a spectrum of structural cardiac malformations characterized by variable underdevelopment of the left heart-aorta complex. A minority of patients having a milder degree of left ventricular hypoplasia, described as hypoplastic left heart complex (HLHC), may be selected for biventricular repair. The objective of this study was to assess the outcome of the biventricular approach in HLHC. We evaluated retrospectively 30 neonates diagnosed with HLHC from the "12 de Octubre" University Hospital, following established criteria. We analyzed the echocardiographic data recorded just after birth and at last follow-up after surgery. All patients were operated on in the neonatal period using various surgical techniques. There were no early deaths and only 1 late death after a mean follow-up of 62.9 ± 43.8 months. All patients presented a significant growth of the left ventricular structures, with a Z-score increase of 1.17 ± 1.05 for mitral annulus, 1.72 ± 1.23 for aortic annulus, and 1.33 ± 1.46 for left ventricular end-diastolic diameter. Postoperatively, 18 patients showed a left valvular stenosis, and 17 patients underwent a reoperation and/or an interventional procedure. Freedom from surgery or interventional catheterizations at 1, 3 and 5 years was 53, 49 and 43%, respectively. The 29 current survivors are all in a good functional status. In our experience, we achieved good results from biventricular repair in patients with HLHC, with a significant growth of left heart structures and an excellent clinical status at a medium-term follow-up. Nevertheless, there was a high rate of reoperations and/or interventional catheterizations.

Comparability of Z-Score Equations of Cardiac Structures in Hypoplastic Left Heart Complex

Hypoplastic left heart complex (HLHC) is characterized by a mitral valve or an aortic valve annular Z score < -2, antegrade flow in the ascending aorta, ductal dependency, coarctation or aortic arch hypoplasia, and absence of significant (sub)valvar stenosis. The Z scores of the mitral and aortic valve annuli are major determinants of HLHC. Therefore, the algorithm for Z-score calculation is essential for diagnosis. However, no single universal method of calculation is in use. In the scientific literature addressing HLHC, various Z-score calculation methods have been applied. The aim of this study was to evaluate Z scores derived from two-dimensional echocardiographic dimensions in patients with HLHC. To compare the different published methods using two-dimensional echocardiographic measures for Z-score calculation, a cohort of 18 newborns diagnosed with HLHC was retrospectively evaluated. In addition, the methods to determine body surface area in newborns were evaluated. Three Z-score calculation methods were included and compared. Using the method of Daubeney et al. to calculate Z scores in our cohort illustrated a lack of correlation beyond a Z score < 0, compared with the methods of Zilberman et al. and Pettersen et al. Z scores calculated using Zilberman et al.'s and Pettersen et al.'s methods were fairly consistent. The equations used by Pettersen et al. are based on the largest population of neonates. Although the different methods for calculating Z scores for mitral and aortic valve dimensions correspond fairly well in the normal range, Z scores < -2 diverge substantially. A useful scientific comparison of published data and outcomes of patients with HLHC remains elusive. The Z-score calculation algorithms used by Pettersen et al. appear to be the most appropriate for use in an evaluation of HLHC. Because these different methods can yield different values, reporting the method as well as the Z score is essential for an accurate diagnosis. Similarly, the method used to determine body surface area should be reported.

Postoperative neurodevelopmental outcome of patients with hypoplastic left heart complex: hybrid versus Norwood strategy

Besides survival, the neurological status of patients after surgical treatment of congenital heart defect constitutes the most important indicator of the outcome in the current era. Nowadays, it is well documented in the literature a state of immaturity of the brain in neonates born with congenital heart disease that makes them particularly susceptible either to newly occurring brain damage or to worsening of pre-existing brain lesions when subjected to cardiopulmonary bypass surgery [1]. This susceptibility would be further enhanced by special techniques used for the reconstruction of the aortic arch, namely the deep hypothermic circulatory arrest or the antegrade lateral cerebral perfusion [2]. This is the main explanation of the clear tendency of some centres to pursue the treatment of congenital heart disease less aggressively than in the past, by restoring traditional palliative techniques or introducing modern interventional tools, all designed to appeal to the extracorporeal circulation, whenever possible, beyond the terms of the fateful neonatal period [3]. The rationale for the hybrid procedure for treatment at the first stage of hypoplastic left heart complex should be exactly that. In spite of such rationale, literature provides controversial data regarding both survival and myocardial performance in patients undergoing hybrid procedure compared with those treated with Norwood operation. For instance, although avoiding cardiopulmonary bypass and cardioplegic arrest, the early postoperative haemodynamic profile of the hybrid procedure has been reported as not being superior to the Norwood in terms of cardiac output and pulmonary blood flow. As a matter of fact, the acute pressure load imposed by the bilateral banding to the already volume-loaded right ventricle would play a detrimental effect on myocardial performance both directly and mediated by increased circulating vasocontrictors. The resultant increase in systemic vascular resistance would be responsible for a potential for pulmonary overcirculation, with somehow elevated Qp:Qs ratios, the major benefit of the hybrid procedure residing in the avoidance of high VO2 states rather then tight control of Qp [4]. The paper by Knirsch et al .[ 5] provides further data to the evidence that deprive the hybrid procedure of the role of panacea revealing a substantial overlap of data regarding the neurodeve

Modified Repair of Interrupted Aortic Arch Utilizing Retroesophageal Right Subclavian Artery Based on a Neonatal Hybrid Approach in Hypoplastic Left Heart Complex

Interrupted aortic arch (IAA) combined with an aberrant right subclavian artery (ARSA) is frequently associated with a hypoplastic ascending aorta. Neonatal surgical therapy carries a high risk particularly for aortic arch obstructions during the further follow-up. We performed a modified reconstruction of the aortic arch utilizing the ARSA as a natural substitute in a staged surgical approach. In a novel approach, the distal part of the ARSA is reimplanted into the brachiocephalic trunk. In three patients, a novel arch reconstruction was successfully performed during complete biventricular repair. In a follow-up of 60 to 87 months, the reconstructed aortic arch has grown without any signs of obstruction in all three patients. Utilizing the ARSA for surgical aortic arch repair is a satisfactory solution, when postnatal borderline left heart obstruction associated with IAA and ARSA is postponed by an initial hybrid approach.

Postnatal Course of Hypoplastic Left Heart Complex and Restrictive Foramen Ovale

Hypoplastic left heart complex is a cardiac malformation at the mildest end of the spectrum of hypoplastic left heart syndrome. Recently, biventricular repair was proposed for such patients without retrograde flow to the ascending aorta. However, the preoperative course of these patients is unclear. This report describes a unique case of this complex with a retrograde flow to the ascending aorta and a restrictive foramen ovale at birth in which the patient ultimately underwent biventricular repair after transient pulmonary congestion and full reversal of aortic and ductal flow.

Borderline hypoplasia of the left ventricle in neonates: Insights for decision-making from functional assessment with magnetic resonance imaging

We sought to compare the usefulness of echocardiography and magnetic resonance imaging in neonates with a borderline small left ventricle. The preoperative magnetic resonance and echocardiography studies of 20 consecutive patients (mean age 10 +/- 9 days) undergoing magnetic resonance imaging were analyzed. The diagnoses were aortic stenosis (n = 3), hypoplastic left heart complex (n = 12), and unbalanced atrioventricular septal defect (n = 5). The magnetic resonance imaging protocol included ventricular volumetry, flow measurements, and angiography. Potential left ventricular volumes, assuming an ideal geometric shape, were calculated by mathematically "unfolding" the compressed left ventricle. Left ventricular end-diastolic volume was 16.0 +/- 7.0 mL/m(2) of body surface area by echocardiography and 33.5 +/- 15.5 mL/m(2) by magnetic resonance imaging. Echocardiography consistently underestimated left ventricular volume and did not correlate with magnetic resonance. Of all echocardiographic parameters, mitral valve z-score was the best predictor of left ventricular end-diastolic volume by magnetic resonance (r = 0.77; P = .02). The average potential volume increase was 8.8% for aortic stenosis, 35.0% for atrioventricular septal defect and 23.0% for hypoplastic left heart complex patients. Aortic valve diameter did not correlate with flow volume in the ascending aorta. Sixteen (80%) of 20 patients underwent biventricular repair, without early mortality. Of these, only 5 (31.3%) had a preoperative left ventricular end-diastolic volume of more than 20 mL/m(2) by echocardiography. Magnetic resonance imaging is feasible in neonates with borderline left ventricular hypoplasia. Echocardiography does not accurately measure left ventricular hypoplasia in these patients and may unfairly preclude some patients from a biventricular repair in whom magnetic resonance is reassuring.

Management options in neonates and infants with critical left ventricular outflow tract obstruction

Despite being one of the most common congenital cardiac abnormalities, the treatment of critical left ventricular outflow tract obstruction (LVOTO) in the neonate and infant remains a significant challenge. Critical LVOTO in the neonate and infant includes continuous and diverse spectrum of anatomic diagnoses ranging from hypoplastic left heart complex to isolated aortic valvular stenosis with otherwise normally formed left heart structures. Depending on related anatomic features, there are multiple single ventricle and biventricular management strategies available for patients with critical LVOTO; all of which carry significant risk of death and requirement for future interventions. Because of the wide array of morphologic lesions and physiologic manifestations, application of the currently available published data to guide decision making in the individual patients can be challenging. Therefore, the aim of this review is to describe the different therapeutic strategies that can be applied to neonates presenting with critical LVOTO taking into consideration each patient's unique physiologic and anatomic findings.

Hybrid Transcatheter–Surgical Palliation

The outcome of patients with hypoplastic left heart (HLH) is determined by many factors, particularly by the first-step palliative procedure in newborns undergoing the Norwood procedure, its Sano modification, or, rarely, through challenging biventricular repairs. Duct stenting combined with bilateral pulmonary artery banding (PAB) is a new method employed as an alternative first-step approach in a number of centers worldwide. We describe this interventional-surgical "hybrid approach" as an additional strategy for the treatment of newborns with HLH syndrome and HLH complex. Between 1998 and April, 2006, 58 newborns underwent ductal stenting and bilateral PAB. These patients underwent surgical bilateral PAB initially, followed by percutaneous duct stenting; the only exception to this were patients in whom duct stenting was performed as a rescue procedure. Various balloon-expandable and self-expandable stents with different widths and lengths were used during the 8-year period of this study. Balloon dilatation of the atrial septum was performed when indicated. This included 5 patients in whom the atrial septum was stented. Aortic arch reconstruction (AAR) combined with a bidirectional cavopulmonary connection (BCPC) was performed at a median age of 4.8 months (range, 2.6-7.5), and total cavopulmonary connection (TCPC) was performed at a median age of 3.1 years (range, 2.5-4). Nine patients were listed for heart transplantation (HTX) and transplanted with AAR when a donor heart was available. Depending on growth of left ventricular structures, biventricular repair (BVR) was performed at a median age of 7.1 months (range, 3.5-10). Overall, 8 of 58 patients (13.8%) treated by the transcatheter-surgical hybrid approach died during the study period. The mortality rate for duct stenting was 1.7% (l/58), and it was 1.7% for bilateral PAB as well. Twenty-seven patients received an AAR/BCPC; 2 of them died (7.4%). Additionally, 1 of 2 patients with AAR/BCPC died while on the waiting list for HTX, resulting in a total mortality rate of 11% with an actuarial survival rate of 89%. One patient is still awaiting AAR + BCPC. Three patients died while on the waiting list for HTX despite successful bilateral PAB and duct stenting. The 30-day mortality rate for TCPC (n = 11), HTX (n = 8), and 18 patients with BVR was 0. The actuarial survival rate for patients with BVR is 93%. Postnatal transcatheter-surgical hybrid palliation expands the surgical options for newborns with HLH. Using hybrid palliation, Norwood stage I operation can be avoided in the neonatal period, the waiting period for children scheduled for cardiac transplantation can be extended, and observation for left ventricular growth suitable for biventricular repair as well.

Blood type incompatible cardiac transplantation in young infants☆

Donor organ shortage in pediatric heart transplantation (HTx) is causing mortality rates of 30-50% on the waiting list. Due to immaturity of the immune system of newborns and infants, ABO-incompatible HTx may be an option to increase donor availability. We present our experience with ABO-incompatible HTx. Three infants were transplanted ABO-incompatible since 12/2004: (1) hypoplastic left heart complex, (2) restrictive hypertrophic cardiomyopathy, (3) dilative cardiomyopathy. Age at HTx was 7, 5, and 3.5 months. All recipients had blood type O, donors were A, A, and B. Informed consent was given by parents, the ethics committee, and Eurotransplant. Preoperative isohemagglutinin titers were low (Patient 1: 1:4 for anti-A1, A2, B, Patient 2: 1:4, 1:1, 1:4 for anti-A1, A2, B, respectively, and Patient 3: 0 for all, but quick spin 1+ for all). Intraoperatively, plasma was separated from red blood cells and discarded up to six times until antibodies were eliminated. Immunosuppressive induction with ATG was started for 5 days. Basic immunosuppression consisted of tacrolimus, mycophenolate mofetil, and prednisone. Extubation was performed on days 15, 2, and 1, respectively. After a follow-up of 17, 16, and 12 months all patients are well, ventricular function is excellent without any acute rejection periods; Patient 1 is still on dialysis. Isohemagglutinin titers against donor blood type have disappeared in follow-up. ABO-incompatible cardiac transplantation shows good short-term results in young infants and seems to be a safe procedure to lower the mortality on the waiting list.

Biventricular repair in patients with hypoplastic left heart complex

Biventricular repair in patients with hypoplastic left heart complex

Biventricular repair in children with hypoplastic left heart complex

Biventricular repair in children with hypoplastic left heart complex

Borderline left ventricle

The first problem to solve when dealing with the topic 'borderline left ventricle' is to find the appropriate definition. Several parameters have been taken into consideration, either morphometric (diameter of the mitral valve, indexed mitral valve area, left ventricular inflow dimension, left ventricular cross-sectional area, ratio between the apex-to-base left ventricular dimension and right ventricular dimension, left ventricular long axis to heart long axis ratio, left ventricular end diastolic volume, left ventricular mass index, ratio of the right/left ventricular wall thickness, presence of endocardial fibroelastosis, cardiac apex not formed by the left ventricle, diameter of the ventriculo-aortic junction, diameter of the aortic valve annulus and indexed aortic root diameter) as well as functional (left ventricular ejection fraction, left ventricular end diastolic pressure, mean pulmonary artery pressure, direction of the blood flow in the ascending aorta and at the level of the patent ductus arteriosus). Pre-operative determination whether the left ventricle is adequate to sustain the systemic circulation, or it may became adequate with the available surgical approaches, and therefore a bi-ventricular type of repair is feasible, can be extremely difficult, particularly in the presence of a 'borderline left ventricle'. In the clinical practice pediatric cardiologists and cardiac surgeons are faced with the problem of the 'borderline left ventricle' in four different groups of congenital heart defects: (a) aortic valve stenosis, (b) aortic coarctation, with or without hypoplastic aortic arch, (c) hypoplastic left heart complex, (d) right ventricular pressure and/or volume overload. In all the above situations in the presence of a left ventricle smaller than normal a very exhaustive approach has been reviewed in the decision making process, taking in account the literature reports as well as the personal experience. In each patient with 'borderline left ventricle' the elements to be considered for the decision making process between uni- and bi-ventricular type of repair, or for less ideal options of management, are the following: morphometric and functional parameters, hemodynamic data, available surgical options, results of the personal and institutional experience.

Indications, criterions, and principles for biventricular repair.

The hypoplastic left heart syndrome constitutes a wide spectrum of cardiac malformations, characterized by varying degrees of underdevelopment of the structures of the left heart and aortic arch. At the severe end of the spectrum, there is aortic and mitral atresia, and the left ventricle is vestigial. In contrast, at the mild end, there is hypoplasia of the left ventricle in the absence of overt stenosis of either the aortic or mitral valves, the combination we have described as hypoplastic left heart complex.1Until recently, debate with regard to the optimal surgical approach has centered on the choice between the Norwood operation and neonatal cardiac transplantation. In the last several years, nonetheless, it has been shown that of biventricular repair can be achieved in those patients at the favorable end of the spectrum that we designated as having the complex rather than the syndrome.1,2It is well recognized that an ongoing difficulty is the inconsistent and imprecise definition of hypoplastic left heart syndrome. In this presentation, I summarize our own criterions, and our principles for biventricular repair, as based on our experience at the Montreal Children's Hospital, for those patients we judge to have the hypoplastic left heart complex.

Biventricular repair in the management of hypoplastic left heart syndrome.

Hypoplastic left heart syndrome is the term introduced by Noonan and Nadas1to describe a spectrum of cardiac anomalies characterized by varying degrees of significant underdevelopment of the left heart and aortic arch. These cardiac anomalies include mitral valvar disease, left ventricular hypoplasia, aortic stenosis at subvalvar, valvar, and supravalvar levels, hypoplasia of the ascending aorta and aortic arch, and aortic coarctation. Although descriptive, hypoplastic left heart syndrome suffers from being a very unspecific term, since it encompasses multiple degrees and combinations of abnormalities involving the left sided structures. In an attempt to provide gradings of severity, Kirklin and Barratt-Boyes2categorized these patients falling into the syndrome into four classes, according to whether obstruction was found at one, two, or more levels, or whether there is aortic atresia. Then, in 1998, Tchervenkov and colleagues3introduced the term hypoplastic left heart complex to describe a set of patients falling within the spectrum of hypoplasia of the left heart, but in the absence of intrinsic aortic or mitral valvar stenosis, this concept subsequently being endorsed by the International Committee established by the Society of Thoracic Surgeons, together with the European Association of Cardiothoracic Surgery, to rationalize the approach to nomenclature and databases.4The analysis offered by Tchervenkov et al.3showed that, in certain circumstances, there are potentially patients considered to have hypoplasia of the left heart who might be candidates for biventricular repair. If this is the case, then it is important to establish how this subset can be recognized, and how they are best treated.