Radiologic Considerations in Heterotaxy: The Need for Detailed Anatomic Evaluation

Polysplenia with situs inversus totalis, azygos continuation of the inferior vena cava, and duplication of the superior vena cava in a healthy adult: A case report

Polysplenia syndrome is an embryological disorder whereby the usual left-right asymmetry of thoracic and abdominal viscera fails to develop. It is a rare entity, estimated to occur at a frequency of 1 in 40,000, and is often associated with cardiac and biliary abnormalities. More than 75% of patients die before the age of 5 years, and even in the absence of cardiac anomalies, only 5%-10% of patients are expected to survive into adulthood without complications. Although polysplenia syndrome encompasses a wide range of anatomic abnormalities, there is no single pathognomonic feature. Hence, the prognosis of patients with polysplenia depends on their anatomy, thus necessitating radiology in their management. Here we present a case of a 56-year-old man with polysplenia syndrome and situs inversus totalis. This presentation is atypical because polysplenia is usually considered a form of situs ambiguus, and cases with situs inversus totalis are exceedingly rare. Also noted in our patient are variations in the great vessels, including aortic arch branches and the venae cavae which are features not typically associated with either polysplenia syndrome or situs inversus totalis. The patient is healthy and asymptomatic at baseline, with his diagnosis being made incidentally. Our case report is the first to describe this unique combination of cardiothoracic and cardiovascular anatomy. It also emphasizes the importance of radiologists in caring for patients with laterality defects. As these disorders are uncommon, more data on their anatomic variations may help provide better medical care to this patient population.

Rare variant of heterotaxy syndrome in childhood in pulmonology clinic

Heterotaxy syndrome is a congenital malformation in which the internal organs of the chest and abdominal cavity have an abnormal location. People suffering from this syndrome have multiple complex defects in the heart, blood vessels, spleen, liver, lungs and other organs. Heterotaxy is a rare pathology that requires a multidisciplinary approach to diagnosis. This article demonstrates a rare case of heterotaxy observed in the pulmonology clinic of the Veltischev Institute.

Diagnostic Modalities in Primary Immunodeficiency

As the field of inborn errors of immunity expands, providers continually update and fine-tune their diagnostic approach and selection of testing modalities to increase diagnostic accuracy. Here, we first describe a mechanistic consideration of laboratory testing, highlighting both benefits and drawbacks of currently clinically available testing modalities. Next, we provide methods in evaluation of patients presenting with concern for inborn errors of immunity as defined by the International Union of Immunological Societies 2019 phenotypic categories: primary antibody deficiencies, cellular and humoral immune deficiency, disorders of the innate immune system, and syndrome-associated and primary immune regulation disorders (PIRDs). Using the suggested approach in this paper as a roadmap highlights the importance of thorough history taking and physical examination as the foundation to guide further diagnostic tests. This is followed by enumeration and functional testing. Finally, to determine the underlying molecular etiology-specific genetic panels, chromosomal microarrays, and broad genetic testing (whole exome sequencing or whole genome sequencing) are available.

Heterotaxy polysplenia syndrome in an adult female with complete endocardial cushion defect

Heterotaxy syndrome is a rare condition characterized by the abnormal arrangement of thoracoabdominal organs across the left-right axis of the body.

It is generally classified as right and left atrial isomerism or asplenia and polysplenia syndrome, even though there are overlaps and uncertainties. The diagnosis of isomerism is typically made by echocardiography. However, multidetector computed tomography and MRI can help in obtaining detailed data on the morphology of the heart, great vessels, the anatomy of the internal organs, and their mutual arrangement that make an accurate diagnosis of heterotaxy syndrome.

The authors present here the imaging findings of the heterotaxy polysplenia syndrome in a 21-year-old female with a complete endocardia cushion defect and a duplicated right renal vein.

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.

Timing of Fontan Completion in Children with Functionally Univentricular Hearts and Isomerism: The Impact of Age, Weight, and Pre-Fontan Arterial Oxygen Saturation

Isomerism, or heterotaxy, impacts morbidity and mortality after various stages of univentricular palliation. Timing of Fontan completing in these patients based on preoperative factors has not been investigated previously. The aim of this study was to determine the impact of preoperative factors on various outcomes including length of hospital stay and duration of chest tubes. A cross-sectional study was conducted. Patients with isomerism having undergone Fontan at the Children's Hospital of Wisconsin between 1998 and 2014 were identified. Preoperative, operative, and postoperative data were collected on these patients. Linear regression analysis was conducted to determine preoperative characteristics associated with various postoperative outcomes. Receiver operator curve analysis was also performed to determine the sensitivity and specificity of age and pre-Fontan arterial oxygen saturation in predicting increased length of hospitalization and increased duration of chest tubes. Younger age and lower pre-Fontan arterial oxygen saturation were associated with increased length of hospitalization while younger age, lower pre-Fontan arterial oxygen saturation, interrupted inferior caval vein, and worse pre-Fontan atrioventricular valve regurgitation were associated with increased length of chest tubes. Age, arterial oxygen saturation, pulmonary arteriovenous malformations, interruption of the inferior caval vein, and atrioventricular valve regurgitation should all be taken into consideration when timing Fontan completion in patients with isomerism. Arterial oxygen saturations between 82 and 84% with an approximate age of 3 years appear to be a time at which it is reasonable to consider Fontan in patients with 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.

Cardiopulmonary Exercise Testing in Fontan Patients With and Without Isomerism (Heterotaxy) as Compared to Patients With Primary Ciliary Dyskinesia and Subjects With Structurally Normal Hearts

Isomerism, also known as heterotaxy, is a clinical entity that impacts multiple organ systems both anatomically and functionally. The airways and lungs are involved in a great number of these patients, leading to increased sinopulmonary symptoms, increased need for oxygenation, and increased postoperative ventilatory support. Additionally, these patients often have congenital heart disease requiring Fontan palliation. What has not been previously described, and is the focus of this study, is the results of cardiopulmonary exercise testing in those who have undergone Fontan palliation with and without isomerism. We have now compared these finding with those from patients with primary ciliary dyskinesia, as many patients with isomerism have ciliary dyskinesia. We identified patients having the Fontan circulation with and without isomerism who had undergone cardiopulmonary exercise testing, comparing the findings from healthy individuals undergoing exercise, and a comparable number of individuals with primary ciliary dyskinesia but no congenital heart disease. We were able to include a total of 68 patients in our study, with 17 in each of the four groups. Cardiopulmonary exercise testing yielded the best results in healthy patients. All patients with the Fontan circulation demonstrated mixed pulmonary disease, although those with isomerism had greater FVC and FEV1. Exercise times did not differ, although peak consumption of oxygen was greater in those with isomerism. Those with ciliary dyskinesia had only obstructive pulmonary disease and had the lowest FEF25-75 between all groups. Those with isomerism had a lesser degree of obstructive pulmonary disease when compared to those with primary ciliary dyskinesia. Patients with the Fontan circulation with and without isomerism have relatively subtle differences in their cardiopulmonary exercise testing, with both groups demonstrating restrictive lung disease. In regard to obstructive lung disease, those with isomerism tend to be more similar to the patients with primary ciliary dyskinesia than those with the Fontan circulation but without isomerism. The results are likely limited by selection bias and highlight the need for multicentric efforts to characterize cardiopulmonary exercise testing in those patients with pulmonary isomerism.

Isomerism in the setting of the so-called "heterotaxy": The usefulness of computed tomographic analysis

The most complex combinations of congenital cardiac malformations are found in the setting of bodily isomerism. The question remains, however, as to whether evidence of cardiac isomerism is always to be found in the setting of bodily isomerism, also known as "heterotaxy." We have previously shown that, when assessed on the basis of the extent of the pectinate muscles relative to the atrioventricular junctions, there is always isomerism of the atrial appendages in this setting. Doubt has been remained, however, as to whether these cardiac features can accurately be recognized during life. We have now encountered two patients showing features of the left and right bodily isomerism. Examinations of these patients made using computed tomography show that all features of isomerism, no matter how complex, can now be visualized during life. The images currently presented show, furthermore, that the features of the so-called "heterotaxy" can be seen during life, not only within the heart but also in all the thoracic and abdominal organs, albeit that the isomeric features are confined to the thoracic organs. Based on the images presented, we argue that if each system of organs is analyzed and described in independent fashion; then it is possible for clinicians to exclude any suggestion of ambiguity and to provide accurate descriptions of the overall arrangement. We further discuss the appropriate terminology to describe the entity we prefer to call isomerism, along with the indications and usefulness of computed tomography in revealing the anatomic features of the congenitally malformed heart.

Characteristics of Hospitalizations for the Glenn Procedure in Those With Isomerism Compared to Those Without

Isomerism, also known as heterotaxy, is a unique clinical entity in which there are mirror imaged findings in the thoracic. In the abdomen, the arrangement of organs can be random. The anatomic findings also have functional consequences. Isomerism has been known to increase morbidity and mortality in those with functionally univentricular hearts. The aim of this study was to determine the impact of isomerism on the Glenn hospitalization. Data from the 1997 to 2012 Kids' Inpatient Database were utilized for this cross-sectional study. Admissions during which a Glenn procedure was done were identified. Next, these admissions were separated into those with and without isomerism. Admission characteristics were then compared in a univariate fashion as well as by regression analysis. Length of hospitalization, cost of hospitalization, extracorporeal membrane oxygenation, and inpatient mortality were the outcomes of interest. A total of 4959 admissions with a Glenn procedure were identified. Of these, 450 were associated with isomerism. The median age at which the Glenn procedure was done was 10 and 13 months in those without and with isomerism, respectively. Neither univariate nor regression analysis demonstrated any significant difference in length of hospitalization, cost of hospitalization, need for extracorporeal membrane oxygenation, and inpatient mortality between those with and without isomerism. Isomerism does not impact the characteristics of the Glenn hospitalization. Those with isomerism did tend to be older when they underwent the Glenn procedure.