Heterotaxy Syndrome: Proceedings From the 10th International PCICS Meeting

27 years of experience with the Fontan procedure: characteristics and clinical outcomes of children in a tertiary referral hospital

BACKGROUND

The Fontan operation has improved the survival of children born with congenital heart disease with single ventricle physiology. The most widely adopted variations of the Fontan procedure are the extracardiac conduit, the lateral tunnel ve the intra/extracardiac conduit with fenestration. Despite advances in the treatment and prevention of early and late complications that may develop after Fontan surgery, morbidity still remains an important problem.

METHODS

304 patients who underwent Fontan surgery in our center between 1995 and 2022 were included in our study. The complications that developed in patients who underwent primary Fontan or lateral tunnel surgery and extracardiac conduit Fontan application were compared.

RESULTS

Classic Fontan surgery and lateral tunnel surgery were performed in 26 of the patients, and extracardiac Fontan surgery was performed in 278 patients. 218 of 304 cases were patients with single ventricular pathology. 86 cases were patients with two ventricular morphologies but complex cardiac pathology. Fenestration was performed in only 6 patients, other patients did not require fenestration. The mean follow-up period of our patients was 12 years (3 months-27 years). When the complications between Fontan procedures were compared in our study, it was found that the length of hospital stay and mortality were statistically significantly reduced in patients who underwent extracardiac Fontan surgery. There was no significant difference in terms of complications that can be seen after Fontan surgery and the length of stay in the intensive care unit.

CONCLUSION

Fontan complex is a palliative surgery for children with complex heart disease. Palliative surgical operations aimed at the preparation of the Fontan circulation lead to the preparation of the pulmonary vascular bed and the preservation of ventricular function. The techniques applied in Fontan surgery affect the early and long-term complications and the survival of the patients. In our study, when we examined the patients who extracardiac conduit Fontan procedure for the non-cardiac route, we found that mortality and morbidity were minimal.

A multi-disciplinary, comprehensive approach to management of children with heterotaxy

Heterotaxy (HTX) is a rare condition of abnormal thoraco-abdominal organ arrangement across the left-right axis of the body. The pathogenesis of HTX includes a derangement of the complex signaling at the left-right organizer early in embryogenesis involving motile and non-motile cilia. It can be inherited as a single-gene disorder, a phenotypic feature of a known genetic syndrome or without any clear genetic etiology. Most patients with HTX have complex cardiovascular malformations requiring surgical intervention. Surgical risks are relatively high due to several serious comorbidities often seen in patients with HTX. Asplenia or functional hyposplenism significantly increase the risk for sepsis and therefore require antimicrobial prophylaxis and immediate medical attention with fever. Intestinal rotation abnormalities are common among patients with HTX, although volvulus is rare and surgical correction carries substantial risk. While routine screening for intestinal malrotation is not recommended, providers and families should promptly address symptoms concerning for volvulus and biliary atresia, another serious morbidity more common among patients with HTX. Many patients with HTX have chronic lung disease and should be screened for primary ciliary dyskinesia, a condition of respiratory cilia impairment leading to bronchiectasis. Mental health and neurodevelopmental conditions need to be carefully considered among this population of patients living with a substantial medical burden. Optimal care of children with HTX requires a cohesive team of primary care providers and experienced subspecialists collaborating to provide compassionate, standardized and evidence-based care. In this statement, subspecialty experts experienced in HTX care and research collaborated to provide expert- and evidence-based suggestions addressing the numerous medical issues affecting children living with HTX.

Unusual long survival in a case of heterotaxy and polysplenia

Heterotaxy syndrome with polysplenia is an extremely rare congenital disorder caused by a disruption in the embryonic development that results in an abnormal arrangement of the abdominal and thoracic organs. We present the case of a 59-year-old female patient with invasive ductal carcinoma of the right breast (luminal A type) and CT findings of heterotaxy syndrome with polysplenia. The most remarkable anomalies identified were a left inferior vena cava draining into the hemiazygos vein, absent inferior vena cava at the thoracic level, and hepatic veins directly draining into the right atrium. Moreover, an atrial septal defect was identified, explaining the pulmonary hypertension of unknown cause previously detected in the patient. The relevance of this case lies in the unusual anatomical abnormalities found and the large patient survival, having in to account the great rate of heterotaxy syndrome mortality in the first years of life.

Nosocomial Severe Bacterial Infection After Cardiac Surgery for Complex Congenital Heart Disease in Heterotaxy Syndrome

BACKGROUND

Patients with heterotaxy syndrome (HS), commonly associated with hyposplenism and complex congenital heart disease (CCHD), require multiple-stage single ventricle type operation for long-term survival. Although a higher risk of community-acquired sepsis and mortality rate was reported in CCHD with HS compared with those without HS, whether the risk of postoperative severe bacterial infection (SBI) is higher in patients with HS remains unknown.

METHOD

All patients with CCHD (with and without HS) born between 2001 and 2013 who received cardiac surgery between 2001 and 2018 were enrolled. We analyzed the epidemiology and risk of postoperative SBI in this CCHD cohort.

RESULT

In total, 101 patients of CCHD with HS and 164 patients without HS were enrolled. The mean postoperative nosocomial SBI rate was 0.73/100 patient-days in patients with HS and 0.56/100 patient-days in patients without HS (P = 0.13). Multivariate Cox regression analysis demonstrated that the most critical risk factor for postoperative SBI was postoperative intubation >14 days. Preoperative risk factors, including a nonstandard surgical procedure and multiple surgeries, but not HS, were associated with an increased risk of postoperative nosocomial SBI. The pathogens of infection were also similar between these 2 groups.

CONCLUSION

Although commonly associated with hyposplenism, patients with HS have similar postoperative SBI risk and pathogens as those with CCHD alone.

Successful Palliation via Kawashima Procedure of an Infant With Heterotaxy Syndrome and Left-Atrial Isomerism

Background

Heterotaxy is a condition of abnormal lateralization of organs across the body's left-right axis, causing multiple congenital malformations. The anatomic manifestations of heterotaxy syndrome generally follow one of two patterns, referred to as right atrial isomerism (with two similar right atria and duplication of right-sided features of multiple organs) and left atrial isomerism (with two similar left atria and duplication of left-sided features of multiple organs). Cardiac surgical intervention for patients with heterotaxy syndrome depends on ventricular physiology and circulatory balance. For patients with single-ventricle physiology, a Fontan operation, which directs systemic venous return to the pulmonary arteries, is the definitive intervention. Prior to a Fontan operation, many patients require one or more palliative surgeries (eg, a Blalock-Taussig-Thomas shunt or bidirectional Glenn/Kawashima procedure) to prepare them for definitive correction.

Case Report

We present the case of a term female neonate who was transferred to our pediatric cardiovascular intensive care unit for management of suspected congenital cardiac disease. Echocardiography confirmed the diagnosis of heterotaxy syndrome with left atrial isomerism, an interrupted inferior vena cava with azygos continuation, and a hypoplastic left ventricle with single-ventricle physiology. At 11 months of age, she underwent a Kawashima procedure with subtotal pulmonary artery ligation. She tolerated the procedure well and is anticipated to remain stable for the near future, possibly without the need for further cardiac surgery.

Conclusion

Patients with heterotaxy syndrome have congenital malformations in several organ systems, requiring lifelong coordination of care among health providers across multiple disciplines.

Heterotaxy Syndrome and Intestinal Rotation Abnormalities

BACKGROUND

Infants with heterotaxy syndrome (HS) have abnormal lateralization of organs along the right-left body axis. Intestinal rotation abnormalities (IRAs) are a potential source of morbidity and mortality. For this study, our objective was to prospectively observe a cohort of infants with HS and determine the incidence and natural history of IRA.

METHODS

Infants ≤6 months of age with HS were enrolled in this prospective observational study. Exclusion criteria were other congenital abnormalities that necessitated abdominal surgery. HS was defined as any arrangement of organs that was not situs solitus or situs inversus along with associated congenital heart disease. The investigation for IRA was at the discretion of each participating center.

RESULTS

Infants were recruited from January 2012 to December 2016. Thirty-eight infants from 7 institutions were included; 22 infants had right isomerism and 16 infants had left isomerism. Twenty-nine infants (76%) were evaluated for IRAs; 21 of 29 evaluations (72%) were abnormal. Eight infants were investigated because of symptoms, and 21 infants were evaluated routinely. The median age at symptom presentation was 46 days (range: 5-171 days). Seven infants had a Ladd procedure; 4 were prophylactic, with 3 as part of a combined procedure, and 3 were emergent. No child suffered acute midgut volvulus over a median follow-up of 1.6 years (range: 0.06-4.93 years).

CONCLUSIONS

IRAs are common in infants with HS. Infants with symptoms presented by 6 months of age. There was no failure of expectant management resulting in midgut volvulus during a median follow-up of 1.6 years.

Segregating bodily isomerism or heterotaxy: potential echocardiographic correlations of morphological findings

BACKGROUND

Bodily isomerism, also referred to as heterotaxy, involves predominantly the thoracic organs, although other organs are usually abnormally positioned. Previously assessed on the basis of splenic anatomy, it is now understood that isomerism is better segregated on the basis of atrial appendage morphology. This allows for anticipation of associated findings. We aimed to assess the accuracy of segregation based on the morphology of the atrial appendages and other structures more easily identified by echocardiography.

METHODS

We reviewed postmortem specimens of hearts from the archives at four institutions categorised as obtained from patients with "heterotaxy". The cardiac structures were analysed using sequential segmental analysis. Non-cardiac structures were also examined if available. Statistical analyses were performed to compare differences in the settings of right as opposed to left isomerism.

RESULTS

Specimens were available from 188 patients. Of these, 57 had left isomerism, and 131 had right isomerism. Atrial appendages were isomeric in all patients. A coronary sinus was found only in left isomerism, whereas a terminal crest, or a Eustachian valve, was found only in right isomerism. Interruption of the inferior caval vein was associated with left isomerism, whereas totally anomalous pulmonary venous connection was associated with right isomerism.

CONCLUSION

Isomerism is uniformly segregated on the basis of the morphology of the atrial appendages, itself defined by the extent of the pectinate muscles. Other features such as the presence of a coronary sinus and systemic venous return can further help with such segregation of isomerism.

Cardiac Embryology and Molecular Mechanisms of Congenital Heart Disease: A Primer for Anesthesiologists

Congenital heart disease is diagnosed in 0.4% to 5% of live births and presents unique challenges to the pediatric anesthesiologist. Furthermore, advances in surgical management have led to improved survival of those patients, and many adult anesthesiologists now frequently take care of adolescents and adults who have previously undergone surgery to correct or palliate congenital heart lesions. Knowledge of abnormal heart development on the molecular and genetic level extends and improves the anesthesiologist's understanding of congenital heart disease. In this article, we aim to review current knowledge pertaining to genetic alterations and their cellular effects that are involved in the formation of congenital heart defects. Given that congenital heart disease can currently only occasionally be traced to a single genetic mutation, we highlight some of the difficulties that researchers face when trying to identify specific steps in the pathogenetic development of heart lesions.

Intestinal malrotation in patients with situs anomaly: Implication of the relative positions of the superior mesenteric artery and vein

PURPOSE

To assess the usefulness of the relative position of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in diagnosing intestinal malrotation in situs anomaly.

MATERIALS AND METHODS

From January 2004 to April 2015, 33 patients with situs anomalies were enrolled in this study who underwent abdominal USG, CT or MRI as well as upper gastrointestinal series (UGIS) or surgery: situs inversus (n=16), left isomerism (n=10), and right isomerism (n=7); age 21.2±23.2years (mean±standard deviation), range 0-72 years. The intestinal malrotation was confirmed with UGIS and/or operation in 16 patients. Relative positions of the SMV to the SMA were classified into four groups by reviewing abdominal USG, CT, or MRI: right sided, left sided, ventral sided, and dorsal sided. The incidence of malrotation was analyzed for each group.

RESULTS

In 16 patients with situs inversus, there was reversed SMA-SMV relationship: left sided (n=11) or ventral sided (n=5). One situs inversus patient with ventral sided SMV had intestinal malrotation (6.25%). 17 patients with situs ambiguus showed various SMA-SMV relationships (ventral sided, n=7; left sided, n=5; right sided, n=4; dorsal sided, n=1). Among them, 15 patients (88.2%) had intestinal malrotation. Two patients with normal rotation had either right sided or dorsal sided SMV.

CONCLUSION

Situs ambiguus was commonly associated with intestinal malrotation with a variable SMA-SMV relationship. Reversal of the mesenteric vascular relationship was observed in situs inversus with normal rotation, not excluding the possibility of intestinal malrotation.