Complications associated with heterotaxy syndrome in Fontan patients

The heterotaxy syndrome: associated congenital heart defects and management

Heterotaxy syndrome (HS) constitutes a spectrum of anomalies arising from embryological errors that result in abnormalities of lateralization involving thoraco-abdominal viscera and culminate in loss of normal asymmetric arrangement of these organs. Besides the unique challenges involved in planning and execution of surgical procedures aimed at correction or palliation of these anomalies, they have the potential to cause profound physiological and immunological consequences in the individual patient due to their cardiac and extra-cardiac manifestations. This article aims to review the literature on this rare and extraordinary subset of developmental anomalies with the intention of familiarizing the reader on the modes of presentation, manifestations, and the variations thereof while dealing with this anomaly. In our institutional experience with HS, 75 consecutive patients were seen between January 2011 and September 2018. Of these, 48 (64%) were confirmed to have isomerism of right atrial appendages (IRAA) and the rest had isomerism of left atrial appendages (ILAA). The cardiac and extra-cardiac manifestations of these patients were listed out. Fifty-four patients (34 with IRAA and 20 with ILAA) underwent 83 surgical procedures. While 49 patients were palliated on the univentricular pathway, 5 underwent biventricular repair. The in-hospital mortality was 7 (13%) in both groups combined (5 for patients with IRAA and 2 for ILAA). In conclusion, the surgical management of HS is associated with satisfactory outcomes in current era.

Characteristics and outcomes of fetuses with laterality defects are the current outcomes better? A single center study

Objective: To analyze the more recent outcomes of fetuses with different laterality defects.Material and methods: Out of 1508 fetuses with congenital heart disease (CHD) diagnosed by echocardiography between January 1995 and December 2015, 94 (6.3%) presented abnormal visceroatrial situs: 42 till December 2002 (group 1, analyzed retrospectively) and 52 since then until December 2015 (group 2, analyzed prospectively). Twenty-one had left isomerism (Lisom), 22 right isomerism (Risom), 16 situs inversus- dextrocardia (SVI-dx), 5 situs inversus- levocardia (SVI-levo), and 30 situs solitus-dextrocardia (SSol-dx).Results: Seventy-six cases (81%) had CHD, more frequently complex atrioventricular defect. Eighteen cases showed normal heart: half of subgroups SVI-dx and SVI-levo, a third of SSol-dx. Postoperative mortality in continuing pregnancy in group 2 was 43.7 versus 40% in group 1, lower in SVs-dx (0 versus 50%) and Lisom (33.3 versus 66.7%), worse in Risom (71.4 versus 25%). Total mortality in group 2 was 48.3 versus 55% in group 1, better in Ssol-dx (37.5 versus 50%) and in Lisom (27.4 versus 71.4%). In isolated forms all but one case are alive.Conclusions: Our fetal cases presented a relevant mortality in both periods. The outcomes were slightly better in a more recent era in SSol and Lisom.What is known about this topic?Out of laterality defects, the heterotaxies (i.e. left and right isomerism) are known to be associated to a relevant mortality in fetal and neonatal cases.Heterotaxies have a variable position of the heart, but some authors evaluated only those with dextrocardia in their studies on different laterality defects.Controversial data are presented in the literature for the outcomes of fetuses with laterality defects. Many large studies analyzed the data of a very long time period in which it is opinable to compare the results of the treatment, because of a recent improved management and surgical techniques.What does this study add?Our study presents an experience of a single center with cases of different types of laterality defects observed during a routine fetal echocardiography, not only heterotaxies.The knowledge of different laterality defects and of their characteristics (association with cardiac and extracardiac anomalies or with normal heart) is useful for the prenatal counseling.We compare the postoperative and total mortality in more recent period (since 2003) with respect to the previous era (1995-2002).

Modification of hemi-Fontan operation for patients with functional single ventricle and anomalous pulmonary venous connection to the superior vena cava: mid-term results

OBJECTIVES

Fontan candidates with mixed totally anomalous pulmonary venous connection often have postoperative pulmonary venous obstruction after cavopulmonary anastomosis. Because some pulmonary venous obstructions have no intimal hypertrophy at reoperation, we considered such pulmonary venous obstructions to be caused by 3D deformities arising from dissection or mobilization of the vessels, and hypothesized that keeping the pulmonary venous branches in a natural position could avoid such obstruction. Here, we evaluated a modified hemi-Fontan strategy consisting of minimal dissection with no division of vessels and patch separation between systemic and pulmonary venous flow.

METHODS

We retrospectively reviewed clinical records of infants with a functional single ventricle and supracardiac anomalous pulmonary venous connection who had undergone this procedure between 2002 and 2012.

RESULTS

Nine infants underwent this procedure (median age, 5.6 months; range 3.2-30), all with right atrial isomerism and several pulmonary venous branches directly and separately connecting to the superior vena cava. In 5 patients, all pulmonary veins drained into the superior vena cava; in 1, the right pulmonary veins drained into the superior vena cava and in 3, a pulmonary venous branch drained into the superior vena cava. The median follow-up was 6.9 years (0.8-13 years). Three patients underwent reoperation for postoperative pulmonary venous obstruction caused by intimal hypertrophy; however, we confirmed no pulmonary venous obstruction caused by 3D deformities on the pulmonary venous branches connecting separately to the superior vena cava. Although 2 patients were effectively relieved from pulmonary venous obstruction, 1 died due to recurrent pulmonary venous obstruction. There was no late death and no sinus-node dysfunction. Eight patients underwent successful Fontan operation and catheterization. The median interval from the Fontan operation to the latest catheterization was 3.7 years (0.9-3.7 years). The median arterial oxygen saturation was 94% (91-97%) and the central venous pressure was 12 mmHg (8-14 mmHg); no deficiency of pulmonary arteries and veins was noted.

CONCLUSIONS

For patients with functional single ventricle and anomalous pulmonary venous connections to the superior vena cava, our novel strategy of second-stage palliation could avoid postoperative pulmonary venous obstruction caused by 3D deformities, but may not eliminate pulmonary venous obstruction caused by intimal hypertrophy.

Non-cardiac issues in patients with heterotaxy syndrome

Management of complex congenital heart disease in patients with Heterotaxy syndrome (HS) has steadily improved. However, there is an insufficient appreciation of various non-cardiac issues that might impact the overall status of these patients. This article briefly reviews the implications of gastrointestinal, immunologic, genitourinary, respiratory, and central nervous system involvement in HS patients with a view to aid in their comprehensive clinical management.

Atrioventricular valve repair for patient with heterotaxy syndrome and a functional single ventricle

Heterotaxy syndrome is a mortality risk factor for patients with complex heart disease. These patients often have common atrioventricular valve (CAVV) morphology and significant atrioventricular valve regurgitation - yet another mortality risk factor in congenital heart disease. Thus, patients with both heterotaxy syndrome and atrioventricular valve regurgitation are at highest risk of mortality. A large number of patients with heterotaxy syndrome have CAVV and a functional single ventricle. These patients are more difficult to operate than patients with biventricular morphology because in the former, the CAVV is often less adapted to systemic afterload than the mitral valve. Herein, we present the results of atrioventricular valve repair surgeries performed at the Okayama University Hospital on patients with heterotaxy syndrome, atrial isomerism, and a functional single ventricle. In addition, we review the current literature in this typically challenging patient population. In-depth understanding of reasonable management strategies and resolution of technical issues will help guide surgeons during this procedure.

Improving outcomes of the surgical management of right atrial isomerism

BACKGROUND

Patients with right atrial isomerism (RAI) have several cardiac malformations historically resulting in significant morbidity and mortality. We sought to assess whether current surgical strategies have improved the outcomes of patients with RAI.

METHODS

A retrospective review of our database from 1997 to 2010 identified 60 consecutive patients with RAI who underwent initial palliation at Mt. Fuji Shizuoka Children's Hospital. All of the patients had a functional single ventricle. Of the 60 patients, 33 patients (51.7%) had obstructed total anomalous pulmonary venous drainage (TAPVD), 23 patients (40.3%) had significant (more than moderate) atrioventricular valvular regurgitation (AVVR), 7 patients (12.3%) had hiatus hernia, and 4 patients (6.7%) had major aortopulmonary collateral arteries. Pulmonary outflow atresia was present in 39 of the patients (65%), and 46 patients had systemic-to-pulmonary artery shunts. Of the 33 patients with TAPVD, 18 underwent repair of the condition at initial palliation, 9 others at the time of a Glenn operation, 2 more through a Fontan operation, and 4 at the interstage between palliative surgeries. Eight of the 23 patients with significant AVVR underwent atrioventricular valve repair at initial palliation, 8 others at the time of Glenn operation, 4 others at the time of Fontan operation, and 3 during the interstage between operations. An initial neonatal surgical procedure was performed in 30 patients (50%). The mean follow-up period for patients in the study was 53.1 months.

RESULTS

Operative mortality after initial palliation was 15.4% (4 of 26 patients) before 2003 and 17.6% (6 of 34 patients) after 2004 (p=NS). Five-year survival was 53.8% before 2003 and 81.7% after 2004 (p=0.035, log-rank test). A multivariate analysis identified persistent AVVR of more than moderate degree (p=0.04) as a factor associated with late mortality.

CONCLUSIONS

The outcomes of surgery for RAI are improving. Neonatal palliative surgery for RAI carries a high operative risk of early mortality, and persistent significant AVVR remains a risk factor for late mortality.

Challenges of Univentricular Physiology in Heterotaxy

Patients with heterotaxy syndrome exhibit an extensive constellation of congenital cardiac malformations, making these patients a challenging group to manage surgically. Many of these patients' hearts do not lend themselves to separation of the pulmonary and systemic circulations except by some modification of the Fontan procedure. Palliative procedures early in life are directed at creating a satisfactory balance of pulmonary and systemic blood flow and at the same time ensuring unobstructed pulmonary venous return. Early conversion from parallel pulmonary and systemic circulations to superior cavopulmonary connections is important, to reduce volume work of the systemic ventricle. Heterotaxy patients are generally considered a high-risk population with respect to eventual Fontan procedure. It is important to appreciate the unique and variable anatomy of the sinus node and conduction system and the potential for occult pulmonary venous obstruction, atrioventricular valve regurgitation, and recurrent cyanosis, which may be related to the development of pulmonary arteriovenous malformations.

Heterotaxy: lessons learned about patterns of practice and outcomes from the congenital heart surgery database of the society of thoracic surgeons

According to The International Society for Nomenclature of Pediatric and Congenital Heart Disease (ISNPCHD), "Heterotaxy is synonymous with 'visceral heterotaxy' and 'heterotaxy syndrome'. Heterotaxy is defined as an abnormality where the internal thoraco-abdominal organs demonstrate abnormal arrangement across the left-right axis of the body. By convention, heterotaxy does not include patients with either the expected usual or normal arrangement of the internal organs along the left-right axis, also known as 'situs solitus', or patients with complete mirror-imaged arrangement of the internal organs along the left-right axis also known as `situs inversus'." or patients with complete mirror-image arrangement of the internal organs along the left-right axis, also known as situs inversus. The purpose of this article is to review the data about heterotaxy in the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database. The investigators examined all index operations in the STS Congenital Heart Surgery Database over 12 years from January 1, 1998 to December 31, 2009, inclusive. This analysis resulted in a cohort of 77 153 total index operations. Of these, 1505 operations (1.95%) were performed in patients with heterotaxy. Of the 1505 index operations performed in patients with heterotaxy, 1144 were in patients with asplenia and 361 were in patients with polysplenia. In every STS -EACTS Congenital Heart Surgery Mortality Category, discharge mortality is higher in patients with heterotaxy compared with patients without heterotaxy (EACTS = European Association for Cardio-Thoracic Surgery). Discharge mortality after systemic to pulmonary artery shunt is 6.6% in a cohort of all single-ventricle patients except those with heterotaxy, whereas it is 10.8% in single-ventricle patients with heterotaxy. Discharge mortality after Fontan is 1.8% in a cohort of all single-ventricle patients except those with heterotaxy, whereas it is 4.2% in single-ventricle patients with heterotaxy. The STS Congenital Heart Surgery Database is largest congenital heart surgery database in North America. This review of data from the STS Congenital Heart Surgery Database allows for unique documentation of practice patterns and outcomes. From this analysis, it is clear that heterotaxy is a challenging problem with increased discharge mortality in most subgroups.

Pulmonary Arteriovenous Malformations in Heterotaxy Syndrome

We report a surgical approach using hepatic vein–to–azygos vein connection without cardiopulmonary bypass or deep hypothermic circulatory arrest in a patient with heterotaxy syndrome and interrupted inferior vena cava with persistence of pulmonary arteriovenous malformations (PAVMs) after previous Fontan completion. We advocate early performance of hepatic vein–to–azygos vein connection following the Kawashima operation for heterotaxy with functionally univentricular heart and interrupted inferior vena cava. We review the physiology of heterotaxy syndrome with congenital heart disease and justify our approach in the context of a review of previous surgical strategies used in this patient population.

Contemporary management of right atrial isomerism: effect of evolving therapeutic strategies

OBJECTIVES

Infants with right atrial isomerism have poor outcomes because of a complex combination of cardiac anomalies. Aggressive management of total anomalous pulmonary venous drainage might have a positive effect on the prognosis.

METHODS

Outcomes of all children with right atrial isomerism from 1994 to the present were reviewed. Management of total anomalous pulmonary venous drainage evolved from no repair or conventional surgical technique to primary sutureless repair on initial palliation. Cox survival models were used to identify variables associated with reduced survival.

RESULTS

There were 55 children enrolled in the study. The median age at the initial visit was 2 days. Fifty-one patients had total anomalous pulmonary venous drainage (obstructive in 22 patients). Withdrawal of treatment occurred in 11 (20%) of 55 patients during an interval of institutional bias toward no treatment. Thirteen (24%) of 55 patients had palliations without total anomalous pulmonary venous drainage repair, and 3 (23%) of 13 survived. Thirty-one (56%) of 55 patients had operations that included total anomalous pulmonary venous drainage repair, of whom 13 (42%) of 31 underwent primary sutureless repair for total anomalous pulmonary venous drainage. Sixteen (52%) of 31 survived, and their current status 1 to 10 years (median, 5.8 years) after repair is post-Fontan (7/16 [44%]), postbidirectional Glenn (6/16 [38%]), and others (3 [20%]). In patients who underwent total anomalous pulmonary venous drainage repair (n = 31), 2 risk factors of decreased survival were identified: drainage site obstruction and infracardiac or mixed-type total anomalous pulmonary venous drainage. After adjustment, sutureless repair appeared to be associated with improved survival (hazard ratio, 0.43), but this beneficial effect did not reach significance (P = .19).

CONCLUSIONS

Mortality continues to be high; however, aggressive total anomalous pulmonary venous drainage repair for right atrial isomerism has resulted in improved survival. The role of primary sutureless repair for total anomalous pulmonary venous drainage remains to be defined.

Surgery for the functionally univentricular heart in patients with visceral heterotaxy

The heterotaxy syndromes are characterized by a high incidence of cardiac anomalies of extreme heterogeneity. Due to this, the surgical management is varied and challenging. Although a minority of patients can undergo biventricular repair, the complexity of the cardiac defects, and the high incidence of ventricular hypoplasia, mandate a surgical approach in the majority of patients depending on the creation of a functionally univentricular heart. Traditionally, the functionally univentricular approach was associated with a high mortality. More recently, the results have been improving as a result of better understanding of these malformations, and logical improvements in surgical technique. In this review, we will make brief comments on the nomenclature and classification of the heterotaxy syndromes, and the range of cardiac anomalies, before concentrating on the surgical treatment for those patients having functionally univentricular hearts in the setting of heterotaxy. More specifically, we will review initial palliation in early life, creation of the cavopulmonary anastomoses, including the Kawashima procedure and the Fontan circulation, and the role of transplantation.

Atrioventricular Valve Procedures with Repeat Fontan Operations: Influence of Valve Pathology, Ventricular Function, and Arrhythmias on Outcome

BACKGROUND

The purpose of this study is to analyze atrioventricular valve procedures when performed in association with repeat Fontan operations and to determine the influence of atrioventricular valvar pathology, ventricular function, and arrhythmias on outcome.

METHODS

Between December 1994 and August 2004, 80 patients had repeat Fontan operations that included arrhythmia surgery (78 of 80), venous pathway revision (78 of 80), atrioventricular valve repair-replacement (15 of 80), and other associated procedures. Mean ages were the following: at operation, 20.3 +/- 8.4 years; at prior Fontan, 7.1 +/- 5.8 years. Atrioventricular valve procedures were performed on 8 functionally mitral and 7 functionally tricuspid valves. The average cross-clamp and cardiopulmonary bypass times were 61.9 +/- 42.8 minutes and 218 +/- 82 minutes, respectively.

RESULTS

Ventricular dysfunction (8% vs 54%, p < 0.0001), valvar dysfunction (13% vs 25%, p < 0.05), and atrial arrhythmias (18% vs 86%, p < 0.0001) increased during the preceding 12.0 +/- 4.7 years before the most recent Fontan operation. Multivariate analysis for death, orthotopic cardiac transplantation (OCT), or renal dialysis showed severe ventricular dysfunction, age greater than 25 years, right or ambiguous functional ventricle, and ischemic time greater than 100 minutes to be highly significant. Notably, cardiac index, elevated end diastolic pressure, and atrial fibrillation were not predictors of outcome. Mitral valve repairs were inconsistent due to probable technical misjudgments; most tricuspid valves could not be repaired. Operative and late mortality were 1.2% and 5.0%, respectively. Emergent and late OCT were 1.2% and 3.7%, respectively.

CONCLUSIONS

Risk factors for poor outcome are severe ventricular dysfunction, right or ambiguous single ventricle, age greater than 25 years, and ischemic time greater than 100 minutes. Mitral valves are potentially more amenable to repair than are tricuspid valves. Prosthetic valve replacement should be considered when valve repair is questionable.