Determinants of repair type, reintervention, and mortality in 393 children with double-outlet right ventricle

Double outlet right ventricle - the 50% rule has always been about the conus

PURPOSE OF REVIEW

There has been much variability in the definition of double outlet right ventricle (DORV) spanning the last century. Historically, emphasis has been placed on the assignment of the great arteries to the right ventricle as a definition of DORV. In this review, we aim to underscore the importance of conal muscle, rather than rules surrounding assignment of great arteries to ventricles. We will be outlining the variability in patient anatomy that results from variations in conal muscle development in DORV, which may not fit perfectly into predefined constructs. This anatomic variability directly determines physiology and surgical repair options.

RECENT FINDINGS

There is a growing appreciation of the utility of cross-sectional imaging in complex DORV, and the generation of patient-specific 3D models with virtual reality simulations for surgical planning. These models improve the prediction of candidacy for biventricular repair and allow the mapping of complex baffle pathways preoperatively.

SUMMARY

DORV is not a disease entity in itself, but rather a vast spectrum of disorders associated with maldevelopment of conal muscle and often abnormal expansion of one the great vessels. Patient-specific 3D models will be crucial for improved surgical planning and patient outcomes.

Current outcomes of live-born children with double outlet right ventricle in Norway

OBJECTIVES

This population-based, comprehensive, retrospective study presented the clinical outcomes of all children born in Norway between 2003 and 2017 with double outlet right ventricle (DORV).

METHODS

All children born with DORV between 2003 and 2017 were identified in the Oslo University Hospital registry. Patients' characteristics, interventions, complications and deaths were recorded. Echocardiographic data were reviewed for classification according to current standards. We investigated time-dependent surgical reintervention and mortality using Kaplan-Meier analyses and determinants of treatment complications, reintervention and death using regression analyses.

RESULTS

Ninety-three children with DORV represented an annual median prevalence of 1.18 per 10 000 births in Norway. Six children received palliative care. With an intention to treat, a surgical route with the primary biventricular repair was followed for 62 children, staged biventricular repair for 15 and univentricular repair for 10 children. Major complications occurred in 1.0% and 6.2% of children following catheter or surgical intervention, respectively. No significant determinants of the complications were identified. Overall survival following treatment was 91.9%, 90.8%, 89.5% and 89.5% and corresponding freedom from surgical reintervention was 88.0%, 79.0%, 74.9% and 69.4% at 1, 2, 5 and 10 years, respectively. The presence of atrioventricular septal defect predicted an increased risk of mortality (hazard ratio: 7.16) but did not increase the risk of surgical reintervention.

CONCLUSIONS

In Norway, most children receive tailored treatment for DORV with low rates of complications, surgical reinterventions and mortality. However, atrioventricular septal defect remains a potential determinant of postoperative death.

3D modeling and printing for complex biventricular repair of double outlet right ventricle

BACKGROUND

Double outlet right ventricle (DORV) describes a group of congenital heart defects where pulmonary artery and aorta originate completely or predominantly from the right ventricle. The individual anatomy of DORV patients varies widely with multiple subtypes classified. Although the majority of morphologies is suitable for biventricular repair (BVR), complex DORV anatomy can render univentricular palliation (UVP) the only option. Thus, patient-specific decision-making is critical for optimal surgical treatment planning. The evolution of image processing and rapid prototyping techniques facilitate the generation of detailed virtual and physical 3D models of the patient-specific anatomy which can support this important decision process within the Heart Team.

MATERILAS AND METHODS

The individual cardiovascular anatomy of nine patients with complex DORV, in whom surgical decision-making was not straightforward, was reconstructed from either computed tomography or magnetic resonance imaging data. 3D reconstructions were used to characterize the morphologic details of DORV, such as size and location of the ventricular septal defect (VSD), atrioventricular valve size, ventricular volumes, relationship between the great arteries and their spatial relation to the VSD, outflow tract obstructions, coronary artery anatomy, etc. Additionally, physical models were generated. Virtual and physical models were used in the preoperative assessment to determine surgical treatment strategy, either BVR vs. UVP.

RESULTS

Median age at operation was 13.2 months (IQR: 9.6-24.0). The DORV transposition subtype was present in six patients, three patients had a DORV-ventricular septal defect subtype. Patient-specific reconstruction was feasible for all patients despite heterogeneous image quality. Complex BVR was feasible in 5/9 patients (55%). Reasons for unsuitability for BVR were AV valve chordae interfering with potential intraventricular baffle creation, ventricular hypoplasia and non-committed VSD morphology. Evaluation in particular of qualitative data from 3D models was considered to support comprehension of complex anatomy.

CONCLUSION

Image-based 3D reconstruction of patient-specific intracardiac anatomy provides valuable additional information supporting decision-making processes and surgical planning in complex cardiac malformations. Further prospective studies are required to fully appreciate the benefits of 3D technology.

Double outlet right ventricle in adults: Anatomic variability, surgical treatment, and late postoperative complications

Double outlet right ventricle (DORV) is a highly complex congenital heart disease (CHD) entity, gaining increasing interest due to the rapid progress of cardiac surgery. The number of patients operated for this congenital defect has been growing since 1980s and over following decades with active transitioning of this cohort into the adult medicine. However, the diversity of initial anomaly and performed interventions makes challenging the management of these patients. This is particularly important in the regions where specialized adult CHD cardiology still remains underdeveloped. In this review, we observe the basic principles of DORV nomenclature, main types of the operations and possible late complications. The article focuses on adult patients and offers illustrations from clinical practice.

Louis J, Raghuveer G, Kochilas L. Outcomes Following Aortic Valve Replacement in Children With Conotruncal Anomalies

OBJECTIVE

Conotruncal anomalies can develop aortopathy and/or aortic valve (AV) disease and AV replacement (AVR) is occasionally needed. We report long-term results and examine factors affecting survival following AVR in this group.

METHODS

We queried the Pediatric Cardiac Care Consortium (PCCC, US database for interventions for congenital heart diseases) to identify patients with repaired conotruncal anomalies and AVR. Long-term outcomes were provided by the PCCC, the US National Death Index, and Organ Procurement and Transplantation Network. Competing risks analysis examined outcomes following AVR (death/transplantation, reoperation) and multivariable regression analysis assessed significant factors.

RESULTS

One hundred six children with repaired conotruncal anomalies underwent AVR (1982-2003). Underlying anomaly was truncus (n = 40), d-transposition (n = 22), type-B interrupted arch (n = 16), double-outlet right ventricle (n = 12), pulmonary atresia with ventricular septal defect (n = 9), tetralogy of Fallot (n = 6), corrected transposition (n = 1). 18 (17%) had prior aortic valvuloplasty (surgical = 12, percutaneous = 6). Median age at AVR was 6.9 years (interquartile range = 2.5-12.4). AV pathophysiology was regurgitation (n = 83, 78%), stenosis (n = 9, 9%), and mixed (n = 14, 15%). AVR type was mechanical (n = 72, 68%), homograft (n = 21, 20%), and Ross (n = 13, 12%). Operative mortality was 13(12%). Infant age at AVR was risk factor (odds ratio = 55, 95% confidence interval [CI] = 6-539, P = .0006). On competing risks analysis, five years after AVR, 6% died or received transplantation, 20% had reoperation. Twenty-five years transplant-free survival was 53%. Factors associated with death after hospital discharge included mitral surgery (hazards ratio [HR] = 11, 95% CI = 3-39, P = .0002), underlying defect (HR = 2, 95% CI = 1-5, P = .446). Twenty years transplant-free survival in conotruncal anomalies group was inferior to matched children undergoing AVR for congenital non-conotruncal disease (61% vs 82%, P = .0012).

CONCLUSIONS

Long-term survival following AVR in children with conotruncal anomalies is inferior to that of isolated congenital AV disease and is linked to an underlying cardiac defect. Although valve type was not associated with survival, infant age was a risk factor for operative mortality. Continuous attrition and high reoperation warrant vigilant monitoring.

Individualized Surgical Reconstruction of the Right Ventricle Outflow Tract in Double Outlet Right Ventricle With Mirror Image-Dextrocardia

Introduction: The purpose of this study was to report our experience in the surgical reconstruction of the right ventricular outflow tract in double outlet right ventricle with a major coronary artery crossing the right ventricular outflow tract in the presence of mirror image-dextrocardia. Methods: From January 2005 to December 2019, 19 double outlet right ventricle patients (median age 4 years) with mirror image-dextrocardia and a major coronary artery crossing the right ventricular outflow tract received surgical repair. An autologous pericardial patch was used to enlarge the right ventricular outflow tract in four patients without pulmonary stenosis and three patients with mild pulmonary stenosis. A valved bovine jugular venous conduit was added to a hypoplastic native pathway in nine patients, among which six patients with moderate pulmonary stenosis received small-sized bovine jugular venous conduit implantation (diameter ≤ 16 mm). In comparison, a large-sized bovine jugular venous conduit (diameter >16 mm) was adopted in a total of three patients with severe pulmonary stenosis. Finally, three patients with preoperative pulmonary hypertension (mean pulmonary artery pressure ≥40 mmHg) did not undergo further intervention of right ventricular outflow tract due to the adequate outflow tract blood flow. Results: There was no hospital mortality. One patient with sub-pulmonary ventricular septal defect and concomitant severe pulmonary hypertension died from respiratory failure 11 months after the operation. Kaplan-Meier survival was 94% at 5, 10 years. Within a mean echocardiographic follow-up of 6.9 ± 3.6 years, a total of two patients received reintervention due to valvular stenosis of the bovine jugular venous conduit (pressure gradient > 50 mmHg at 4 and 9 years) after surgical operation. Actuarial freedom from reoperation was 90 and 72% at 5 and 10 years, respectively. During the last echocardiographic follow-up phase, all the survivors were in NYHA class I. Conclusions: Double outlet right ventricle with mirror image-dextrocardia is a rare and complicated congenital cardiac malformation. Surgical reconstruction of the right ventricular outflow tract should be individualized based on the degree of pulmonary stenosis and the specific anatomical features of each patient. Reconstructing the pulmonary artery using the various sizes of valved bovine jugular venous conduit is a safe and effective surgical method.

Narrative review of assessing the surgical options for double outlet right ventricle

The individualized surgical approach in individuals with both arterial trunks arising from the morphologically right ventricle is dictated by the extreme morphological variability encountered in this setting, with each patient being unique. An individualized surgical approach has been designed to take account of the morphological variations, identifying the anatomy with the preoperative three-dimensional CT scan reconstruction. The key features have been considered the distance between tricuspid and pulmonary valves, the size and location of the interventricular communication, and the relationship between the outflow tracts. The surgical approach is tailored, whenever feasible, to create a connection between left ventricle and aorta, but primarily to achieve biventricular repair. Account has been taken of all available surgical options already reported in the literature, identifying the most suitable to provide the best outcomes for each unique morphology. To date, meaningful comparison between different reported surgical series has been difficult because of the marked variation of individual intracardiac morphology, and the lack of reports of specific surgical approaches for well-categorized groups of patients. Our approach, being tailored to the individual cardiac morphology, can be offered to any patient with this ventriculo-arterial connection. Given the difficulties of diagnosis, and the multiple therapeutic indications, very close collaboration between cardiologists and surgeons is indispensable for further progress in the understanding and management of this complex congenital cardiac lesion.

Conversion of prior univentricular repairs to septated circulation: Case selection, challenges, and outcomes

Objectives

Complex congenital heart defects that present earlier in life are sometimes channelled in the single ventricle pathway, because of anatomical or logistic challenges involved in biventricular correction. Given the long-term functional and survival advantage, and with the surgeons' improved understanding of the cardiac anatomy, we have consciously explored the feasibility of a biventricular repair in these patients when they presented later for Fontan completion. We present a single institution's 10-year experience in achieving biventricular septation of prior univentricular repairs, the technical and physiological challenges and the surgical outcomes.

Methods

Between June 2010 and December 2019, 246 patients were channelized in the single ventricle pathway, of which 32 patients were identified as potential biventricular candidates at the time of evaluation for Fontan palliation, considering their anatomic feasibility. The surgical technique involves routing of the left ventricle to the aorta across the ventricular septal defect, ensuring an adequate sized right ventricular cavity, establishing right ventricle-pulmonary artery continuity and taking down the Glenn shunt with rerouting of the superior vena cava to the right atrium. This is a retrospective study where we reviewed the unique physiological and surgical characteristics of this subset of patients and analysed their surgical outcomes and complications.

Results

Biventricular conversion was achieved in all cases except in 3 patients, who had the Glenn shunt retained leading to a one and a half ventricle repair. The average age of the patients was 4.9 years of whom 18 were male. The average cardiopulmonary bypass time was 371 min with an average cross clamp time of 162 min. There was one mortality in a patient with corrected transposition of great arteries (c-TGA) with extensive arterio-venous malformations (AVMs). At a median follow-up of 60 months, all patients remained symptom free except two with NYHA II symptoms, one being treated for branch pulmonary artery stenosis with balloon dilatation and the other with multiple AVMs who needed coil closure. One patient with branch pulmonary artery (PA) stenosis required balloon dilatation and stent placement.

Conclusion

The possibility of achieving the surgical goal in this unique subset of patients evolves with the progressive experience of the congenital heart surgeon. Case selection is a crucial aspect in achieving the desired outcome, and this 'borderline' substrate is often recognized at the time of evaluation for the Fontan completion. A comprehensive preoperative imaging and planning helps in achieving the surgical septation and reconnection to achieve the desired physiological circulation. Though technically challenging, the surgery has excellent short- and mid-term outcomes as evidenced by our 10-year experience.

Repair of double outlet right ventricle: Midterm outcomes

OBJECTIVE

Double outlet right ventricle (DORV) is a complex cardiac malformation with many anatomic variations and various approaches for surgical repair. This study aimed to describe the clinical outcomes of biventricular (BiV) repair for DORV.

METHODS

Patients with DORV, who underwent BiV repair between January 2000 and December 2017 were retrospectively reviewed. Group 1 underwent primary BiV repair, whereas group 2 underwent staged BiV repair over a series of operations. The decision to pursue staged approach included complexity of intracardiac anatomy, age of the patient, and the size and function of the ventricles and the atrioventricular valves. Time-dependent surgical reintervention for LVOTO and mortality were evaluated using Kaplan-Meier survival analysis.

RESULTS

A total of 238 patients with DORV underwent BiV repair at a median age of 6.2 months (range, 1.1 month-27.5 years) (158 in group 1, 80 in group 2). Twenty-two patients (7.8%) required surgical reintervention within 30 days of BiV repair. Overall survival at 5 years was 89.0%. Freedom from LVOTO reoperation at 5 years was 84%. Primary outcomes were not significantly different between groups. CAVC repair and right ventricle to pulmonary artery conduit at BiV repair were associated with higher surgical reintervention (hazard ratio, 2.9 and 1.75, respectively).

CONCLUSIONS

Patients with DORV and complex anatomy may undergo staged BiV repair with acceptable outcomes. Although LVOTO is a potential complication in these patients, the rate of surgical reintervention for LVOTO does not differ significantly from patients undergoing primary BiV repair.

Anatomical Repair Conversion After Bidirectional Cavopulmonary Shunt for Complex Cardiac Anomalies: Palliation is Not a One-Way Path

Complex cardiac anomalies are sometimes channeled toward Fontan palliation for various reasons. Nevertheless, anatomical repair after bidirectional cavopulmonary shunt may be another option with theoretical benefits. In this study, we report our experience with anatomical repair conversion in challenging patients who had been palliated with bidirectional cavopulmonary shunt. Retrospective review was conducted in patients who underwent anatomical repair conversion from prior bidirectional cavopulmonary shunt palliation between January 2008 and March 2016. Patients who underwent a planned staged 1½-ventricular repair were excluded. Twenty-three patients underwent anatomical repair conversion at a median age of 6.5 years (range 2.7-20.0 years). The interval time between palliation and conversion was 4.6 ± 2.4 years (range 0.9-12.4). Indications for conversion were high-risk Fontan candidates (n = 11) and preference for biventricular anatomy (n = 12). In eight of the patients, bidirectional cavopulmonary shunts were taken down and superior vena cava was reconnected to the right atrium with Gore-Tex tube or bovine jugular venous tube. Mean cardiopulmonary bypass and aortic cross-clamp times were 225.6 ± 107.0 and 138.3 ± 76.6 min, respectively. After a mean follow-up of 2.7 ± 2.2 years, there was no mortality and reoperation. No patients presented sinoatrial node dysfunction and superior venous cave stenosis. All the patients were in the New York Heart Association functional class I or II. Patients with previous bidirectional cavopulmonary shunt should be re-evaluated before completion of Fontan and, if cardiac anatomy allows, anatomical repair conversion may be considered, especially in patients with high-risk Fontan completion. Initial bidirectional cavopulmonary shunt palliation should not be considered as a one-way path to Fontan. Although technically challenging, early- and mid-term clinical results of anatomical repair conversion were satisfactory.

Biventricular Repair of Double Outlet Right Ventricle: Preoperative Echocardiography and Surgical Outcomes

OBJECTIVE

To discuss the key anatomic features of double outlet right ventricle (DORV) assessed by preoperative echocardiography among patients treated with different types of biventricular repair.

METHODS

Surgical and echocardiographic databases were queried to identify patients who had undergone biventricular repair for DORV and had adequate preoperative echocardiographic imaging. All patients underwent pre- and postoperative echocardiography and clinical evaluation following discharge.

RESULTS

Two hundred sixty-two patients with DORV met the inclusion criteria of the study. The patients were divided into two groups-intraventricular tunnel repair (IVR) to the aorta (194 [74%] patients) or to the pulmonary artery with either concomitant arterial switch operation or double-root translocation (68 [26%] patients). Among 68 patients undergoing IVR to the pulmonary artery, 50 patients with transposition of the great arteries (TGA) type of DORV and 7 patients with remote ventricular septal defect (VSD) type underwent IVR plus arterial switch operation and 6 patients with TGA type and 5 patients with remote VSD type underwent IVR plus double-root translocation. There were three hospital deaths and one late death (overall operative mortality: 1.5%).

CONCLUSION

Preoperative echocardiography provided crucial data to estimate the feasibility of intraventricular tunnel creation to either the aorta or the pulmonary artery and to guide the selection of either arterial switch or double-root translocation. Biventricular repair could be achieved with favorable outcomes in most patients with DORV.

[Cyanosis in a calf with a double outlet right ventricle]

A 4-day-old female Holstein Friesian calf was presented for evaluation of cyanosis and dyspnea. On auscultation, severe bronchovesicular sounds and a systolic heart murmur of grade IV/VI above the tricuspid valve were found. On echocardiography, a marked dextroposition of the aorta (> 50% originating from the right ventricle), leading to both great arteries arising from the right ventricle - a so-called double-outlet right ventricle - was detected. Two ventricular septal defects were present, one in the perimembranous, subpulmonary region, the other non-committed in the muscular region. The subpulmonary ventricular septal defect was responsible for the shunting of unoxygenated blood into the aorta. Additionally, an aneurysma-like atrial septal defect (type secundum) and a large patent ductus arteriosus were visualized. The main pulmonary artery was severely enlarged without the presence of a stenotic defect. The findings could be verified by angiography. Additionally, a diffuse hypoplastic ascending aorta was visualized. Necropsy confirmed the echocardiographic and angiographic findings.

Surgical Treatment for Double Outlet Right Ventricle With Pulmonary Outflow Tract Obstruction

BACKGROUND

Double outlet right ventricle (DORV) is a conotruncal anomaly that is a defining element of many types of complex congenital heart disease. Because of a big variety of pathology, there are still some controversies with respect to the definition, classification, and surgical treatment. We report our experience with surgical treatment for DORV (as defined by the "90% rule") with pulmonary outflow tract obstruction (POTO).

METHODS

From July 2005 to July 2015, 90 patients underwent surgical treatment of DORV with POTO at the First Hospital of Tsinghua University. There were 55 males and 35 females whose age varies from 3 months to 36 years (mean age 7.1 ± 9.0 years old), and body weights ranged from 5 to 63 kg (mean weight 20.4 ± 16.6 kg). Besides DORV, ventricular septal defect, and POTO, this group of patients includes some with additional associated cardiac abnormalities.

RESULTS

Fourteen patients (15.6%) died. The main cause of death was low cardiac output syndrome.

CONCLUSIONS

The DORV is usually associated with a variety of cardiac abnormalities and POTO is a common defining feature. Acceptable surgical results can be achieved by individualized surgical treatment of most patients. Some patients may require reoperation, and a close follow-up is needed.

Echocardiographic Classification and Surgical Approaches to Double-Outlet Right Ventricle for Great Arteries Arising Almost Exclusively from the Right Ventricle

Selecting an appropriate surgical approach for double-outlet right ventricle (DORV), a complex congenital cardiac malformation with many anatomic variations, is difficult. Therefore, we determined the feasibility of using an echocardiographic classification system, which describes the anatomic variations in more precise terms than the current system does, to determine whether it could help direct surgical plans. Our system includes 8 DORV subtypes, categorized according to 3 factors: the relative positions of the great arteries (normal or abnormal), the relationship between the great arteries and the ventricular septal defect (committed or noncommitted), and the presence or absence of right ventricular outflow tract obstruction (RVOTO). Surgical approaches in 407 patients were based on their DORV subtype, as determined by echocardiography. We found that the optimal surgical management of patients classified as normal/committed/no RVOTO, normal/committed/RVOTO, and abnormal/committed/no RVOTO was, respectively, like that for patients with large ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries without RVOTO. Patients with abnormal/committed/RVOTO anatomy and those with abnormal/noncommitted/RVOTO anatomy underwent intraventricular repair and double-root translocation. For patients with other types of DORV, choosing the appropriate surgical approach and biventricular repair techniques was more complex. We think that our classification system accurately groups DORV patients and enables surgeons to select the best approach for each patient's cardiac anatomy.

Surgical Treatment of Double Outlet Right Ventricle Complicated by Pulmonary Hypertension

Background:

Double outlet right ventricle (DORV) is a group of complex congenital heart abnormalities. Preoperative pulmonary hypertension (PH) is considered an important risk factor for early death during the surgical treatment of DORV. The aim of this study was to report our experience on surgical treatment of DORV complicated by PH.

Methods:

From June 2004 to November 2016, 61 patients (36 males and 25 females) aged 2 weeks to 26 years (median: 0.67 years and interquartile range: 0.42–1.67 years) with DORV (two great arteries overriding at least 50%) complicated by PH underwent surgical treatment in our center. All patients were categorized according to surgical age and lesion type, respectively. Pulmonary artery systolic pressure (PASP), pulmonary artery diastolic pressure (PADP), and mean pulmonary artery pressure (mPAP) were measured directly before cardiopulmonary bypass (CPB) was established and after CPB was removed. An intracardiac channel procedure was performed in 37 patients, arterial switch procedure in 19 patients, Rastelli procedure in three patient, Senning procedure in one patients, and Mustard procedure in one patient. The Student's t-test and Chi-squared test were performed to evaluate clinical outcomes of the surgical timing and operation choice.

Results:

Fifty-five patients had uneventful recovery. PASP fell from 55.3 ± 11.2 mmHg to 34.7 ± 11.6 mmHg (t = 14.05, P < 0.001), PADP fell from 29.7 ± 12.5 mmHg to 18.6 ± 7.9 mmHg (t = 7.39, P < 0.001), and mPAP fell from 40.3 ± 10.6 mmHg to 25.7 ± 8.3 mmHg (t = 11.85, P < 0.001). Six (9.8%) patients died owing to complications including low cardiac output syndrome in two patients, respiratory failure in two, pulmonary hemorrhage in one, and sudden death in one patient. Pulmonary artery pressure (PAP) dropped significantly in infant and child patients. Mortality of both infants (13.9%) and adults (33.3%) was high.

Conclusions:

PAP of patients with DORV complicated by PH can be expected to fall significantly after surgery. An arterial switch procedure can achieve excellent results in patients with transposition of the great arteries type. Higher incidence of complications may occur in patients with ventricular septal defect (VSD) type before 1 year of age. For those with remote VSD type, VSD enlargement and right ventricle outflow tract reconstruction are usually required with acceptable results. The degree of aortic overriding does not influence surgical outcome.

Application of Virtual Three-Dimensional Models for Simultaneous Visualization of Intracardiac Anatomic Relationships in Double Outlet Right Ventricle

Our goal was to construct three-dimensional (3D) virtual models to allow simultaneous visualization of the ventricles, ventricular septal defect (VSD) and great arteries in patients with complex intracardiac anatomy to aid in surgical planning. We also sought to correlate measurements from the source cardiac magnetic resonance (CMR) image dataset and the 3D model. Complicated ventriculo-arterial relationships in patients with complex conotruncal malformations make preoperative assessment of possible repair pathways difficult. Patients were chosen with double outlet right ventricle for the complexity of intracardiac anatomy and potential for better delineation of anatomic spatial relationships. Virtual 3D models were generated from CMR 3D datasets. Measurements were made on the source CMR as well as the 3D model for the following structures: aortic diameter in orthogonal planes, VSD diameter in orthogonal planes and long axis of right ventricle. A total of six patients were identified for inclusion. The path from the ventricles to each respective outflow tract and the location of the VSD with respect to each great vessel was visualized clearly in all patients. Measurements on the virtual model showed excellent correlation with the source CMR when all measurements were included by Pearson coefficient, r = 0.99 as well as for each individual structure. Construction of virtual 3D models in patients with complex conotruncal defects from 3D CMR datasets allows for simultaneous visualization of anatomic relationships relevant for surgical repair. The availability of these models may allow for a more informed preoperative evaluation in these patients.

Surgical outcomes of 380 patients with double outlet right ventricle who underwent biventricular repair

OBJECTIVES

The study objective was to report the outcomes of biventricular repair in patients with double outlet right ventricle.

METHODS

Patients with double outlet right ventricle who underwent biventricular repair at Fuwai Hospital from January 2005 to December 2012 were included. Patients were excluded if double outlet right ventricle was combined with atrioventricular septal defect, heterotaxy syndrome, atrioventricular discordance, or univentricular physiology.

RESULTS

A total of 380 consecutive patients with a mean age of 1.9 ± 2.1 years (range, 1 month to 6 years) were included. Varied types of biventricular repair were customized individually. Follow-up was 90.4% complete, and the mean follow-up time was 3.4 ± 3.9 years. There were 17 (4.5%) early deaths and 7 (2.1%) late deaths. Preoperative pulmonary hypertension was the only risk factor for early mortality. Postoperative significant left ventricular outflow tract obstruction was present in 9 survivors. Patients with noncommitted ventricular septal defect had a longer crossclamp time, longer cardiopulmonary bypass time, and higher incidence of postdischarge left ventricular outflow tract obstruction. There were 4 reoperations, all of which were caused by subaortic left ventricular outflow tract obstruction. All of the pressure gradients were decreased to less than 20 mm Hg after the modified Konno procedure with an uneventful postoperative course.

CONCLUSIONS

Optimal results of varied types of biventricular repair for double outlet right ventricle have been acquired. Although noncommitted ventricular septal defect is technically difficult, the outcomes of patients are favorable. Late-onset left ventricular outflow tract obstruction is the main reason for reoperation but can be successfully relieved by the modified Konno procedure.

Perioperative Management of DORV

The diagnosis of double-outlet right ventricle (DORV) characterizes a complex heterogeneous group of congenital cardiac malformations for which multiple classification schemes have been used. A clear understanding of the anatomy is critical to understanding the physiologic consequences of the specific type of DORV. Perioperative considerations include the medical management of the patient during the preoperative period, anesthetic and surgical management, and postoperative care. Both anesthetic and surgical management strategies are very different depending on the type of DORV. Key principles for anesthetic management include balancing the systemic and pulmonary circulations, optimizing systemic cardiac output, and closely monitoring for impaired oxygen delivery to the tissues. Depending on the specific anatomy the patient is usually placed on a 1- or 2-ventricle pathway, and initial palliation may involve placement of a systemic arterial to pulmonary artery shunt or pulmonary artery banding. In some cases the child may undergo a complete repair during the first few months of life. Surgical outcomes, both short and long-term, are dependent on the type of DORV and surgical procedure done. These patients require long-term follow up and may present for surgical or catheter-based interventions as adults.

Two-ventricle repair for complex congenital heart defects palliated towards single-ventricle repair

OBJECTIVES

Complex congenital heart defects that present earlier in life are sometimes channelled towards single-ventricle repair, because of anatomical or logistic challenges involved in two-ventricle correction. Given the long-term functional and survival advantage, we have been consciously exploring the feasibility of a biventricular repair in these patients when they present later for Fontan completion.

METHODS

Since June 2009, 71 patients were referred for staged completion of the Fontan procedure. Following detailed evaluation that included three-dimensional echocardiography and magnetic resonance imaging, 10 patients (Group 1-median age 6 years) were identified and later underwent complex biventricular repair with takedown of Glenn shunt, while completion of extracardiac Fontan repair was done in 61 patients (Group 2-median age 7 years).

RESULTS

Two-ventricle repair was accomplished in all the 10 Group 1 patients. One patient developed complete heart block requiring permanent pacemaker insertion. Late patch dehiscence occurred in another (awaiting repair). At a median follow-up of 15 months, there was no mortality among the Group 1 patients and all except for 1 patient were symptom free. There were 2 early deaths (3.3%) in the Group 2 patients.

CONCLUSIONS

Two-ventricular repair, although surgically challenging, should be considered in all patients with two functional ventricles who come for Fontan completion. Comprehensive preoperative imaging and meticulous planning helps in identifying suitable candidates.

The Pathological Spectrum of Left-Ventricular Hypoplasia

Left-ventricular (LV) hypoplasia encompasses a range of LV sizes, varying from a mildly underdeveloped, but functionally adequate, chamber to the miniscule, barely perceptible LV cavity seen in hypoplastic left-heart syndrome. Associated malformations include obstructive lesions of LV inflow, outflow, and the aortic arch, often in combination. Repair of complex combinations and/or severe LV hypoplasia usually results in a single-ventricle anatomy with the right ventricle serving as the systemic ventricle. New therapeutic interventions, including fetal procedures, are expanding the spectrum of lesions and LV sizes that may be amenable to a biventricular repair. These surgical considerations place renewed emphasis on understanding the anatomical features associated with LV hypoplasia. This review details pathological features of the full spectrum of LV hypoplasia, particularly those with borderline severe hypoplasia. Primary defining lesions are described as well as additional lesions that may affect clinical symptoms, surgical repair, and long-term outcome.

The role of the Fontan operation in the treatment of congenitally corrected transposition of the great arteries

Congenitally corrected transposition of the great arteries (ccTGA) is a complex cardiac anomaly with an unfavorable natural history. Surgical treatment has been available for over 50 years. Initial procedures used for ccTGA did not correct atrio-ventricular discordance, leaving the right ventricle in systemic position. In the past two decades anatomic repair has been considered to be a better option. Many cases subjected to anatomic repairs would also be suitable for the Fontan strategy, which probably has a lower initial risk. The rationale for use of the Fontan operation in management of congenitally corrected transposition is discussed in this review, with comparisons to other strategies.

The impact of the length between the top of the interventricular septum and the aortic valve on the indications for a biventricular repair in patients with a transposition of the great arteries or a double outlet right ventricle

The purpose of this study was to establish a useful cut-off level for performing an original Rastelli-type operation in patients with transposition of the great arteries (TGA)/ventricular septal defect (VSD) or double outlet right ventricle (DORV). A total of 43 patients with TGA/VSD or DORV who underwent an original Rastelli-type operation in this institute between March 1993 and January 2009 were reviewed retrospectively. These patients were divided into two groups using the length between the top of the interventricular septum and the aortic valve (IVS-AV length); Group A; IVS-AV length <80% of normal left ventricular end-diastolic diameter (LVDd). Group B; IVS-AV length > or =80% of normal LVDd. Group A had a significantly better survival than Group B (100% vs. 56%, P=0.001). The cardiac event-free survival were 89.1% at 7.2 years in Group A and 26.3% at 8.4 years in Group B (P<0.0001). The Group B had a higher incidence of left ventricular outflow tract obstruction (LVOTO; 3% vs. 33%, P=0.02). The IVS-AV length was found to be a significant risk factor for mortality and LVOTO. The IVS-AV length should, therefore, be taken into consideration when selecting the optimal surgical procedures for these patients.

The practical clinical value of three-dimensional models of complex congenitally malformed hearts

OBJECTIVE

Detailed 3-dimensional anatomic information is essential when planning strategies of surgical treatment for patients with complex congenitally malformed hearts. Current imaging techniques, however, do not always provide all the necessary anatomic information in a user-friendly fashion. We sought to assess the practical clinical value of realistic 3-dimensional models of complex congenitally malformed hearts.

METHODS

In 11 patients, aged from 0.8 to 27 years, all with complex congenitally malformed hearts, an unequivocal decision regarding the optimum surgical strategy had not been reached when using standard diagnostic tools. Therefore, we constructed 3-dimensional virtual computer and printed cast models of the heart on the basis of high-resolution whole-heart or cine magnetic resonance imaging or computed tomography. Anatomic descriptions were compared with intraoperative findings when surgery was performed.

RESULTS

Independently of age-related factors, images acquired in all patients using magnetic resonance imaging and computed tomography proved to be of sufficient quality for producing the models without major differences in the postprocessing and revealing the anatomy in an unequivocal 3-dimensional context. Examination of the models provided invaluable additional information that supported the surgical decision-making. The anatomy as shown in the models was confirmed during surgery. Biventricular corrective surgery was achieved in 5 patients, palliative surgery was achieved in 3 patients, and lack of suitable surgical options was confirmed in the remaining 3 patients.

CONCLUSION

Realistic 3-dimensional modeling of the heart provides a new means for the assessment of complex intracardiac anatomy. We expect this method to change current diagnostic approaches and facilitate preoperative planning.