Asymptomatic left isomerism with preduodenal portal vein: computed tomography appearance.

Left isomerism (polysplenia), one of the two major variants of heterotaxia with right isomerism (asplenia), may be rarely diagnosed in adulthood. Most cases are nevertheless asymptomatic and incidentally detected during imaging or surgery performed for unrelated conditions. We hereby report a case of left isomerism fortuitously diagnosed in a 55-year-old man with unrelated tachy-cardiomyopathy. Thoraco-abdominal computed tomography revealed a typical preduodenal portal vein (PDPV) associated with a large series of other occult anatomic variations comprising: polysplenia, agenesis of both pancreatic body and tail, complete non-rotation of the bowel and finally azygous continuation of the inferior vena cava. Subtle but highly specific thoracic features of left isomerism were also found with a bilobed right lung and bilateral long hyparterial main bronchi. The features of adult left isomerism are remembered with special attention to the PDPV.

Laterality defects in the national birth defects prevention study (1998-2007): birth prevalence and descriptive epidemiology.

Little is known epidemiologically about laterality defects. Using data from the National Birth Defects Prevention Study (NBDPS), a large multi-site case-control study of birth defects, we analyzed prevalence and selected characteristics in children born with laterality defects born from 1998 to 2007. We identified 517 nonsyndromic cases (378 heterotaxy, 73.1%; 139 situs inversus totalis [SIT], 26.9%) resulting in an estimated birth prevalence of 1.1 per 10,000 live births (95% confidence interval 1.0­1.2). Prevalence did not differ significantly across sites, over time, or by inclusion of pregnancy termination. Laterality defects were more common among preterm cases compared to term cases, and in children born to mothers who were non-white or younger than 20 years compared to white mothers or those age 25­29 years. The distribution of associated cardiac and extra-cardiac defects, excluding the expected heterotaxy anomalies, varied by type of laterality defect. Cases with heterotaxy were significantly more likely than those with SIT to have double outlet right ventricle, atrioventricular canal defects, pulmonary stenosis, non-tetralogy of Fallot pulmonary atresia with ventricular septal defect, totally and partially anomalous pulmonary venous return; also more likely to have orofacial clefts, esophageal atresia, bowel atresias, and omphalocele, though not reaching statistical significance. Relatively more common among cases with SIT were Dandy- Walker malformation, anotia/microtia, and limb deficiency. The similarity in the demographic characteristics of heterotaxy and SIT supports the hypothesis that they are part of a continuum of abnormal left-right axis patterning. These findings on laterality defects may help guide clinical care, future research, and prevention strategies.

Heterotaxy syndrome - An unusual cause for bowel obstruction in an adult.

Heterotaxy syndrome, also known as situs ambiguous, is a spectrum of pathology due to loss of the normal right-to-left asymmetry of the thoraco-abdominal organs. This report describes the case of a 39-year-old female, previously well, who presented with bowel obstruction. CT showed features of left isomerism, with malrotation and volvulus. Contribution: Heterotaxy syndrome consists of cardiac and non-cardiac manifestations. Imaging studies play a crucial role in the individualised management of the patient.

Laterality Defects in Primary Ciliary Dyskinesia: Relationship to Ultrastructural Defect or Genotype.

Rationale: The association between organ laterality abnormalities and ciliary ultrastructural defect or genotype in primary ciliary dyskinesia is poorly understood. Objectives: To determine if there is an association between presence and/or type of laterality abnormality and ciliary ultrastructural defect or genotype. Methods: Participants with primary ciliary dyskinesia in a multicenter, prospective study were grouped based on ciliary ultrastructural defect or genotype. In a retrospective analysis of these data, the association of ciliary ultrastructural defect or genotype and likelihood of a laterality abnormality was evaluated by logistic regression adjusted for presence of two loss-of-function versus one or more not-loss-of-function variants. Results: Of 559 participants, 286 (51.2%), 215 (38.5%), and 58 (10.4%) were identified as having situs solitus, situs inversustotalis, and situs ambiguus, respectively; heterotaxy, defined as situs ambiguus with complex cardiovascular defects, was present in 14 (2.5%). Compared with the group with inner dynein arm defects with microtubular disorganization, laterality defects were more likely in the outer dynein arm defects group (odds ratio [OR], 2.07; 95% confidence interval [CI], 1.21-3.54; P < 0.01) and less likely in the normal/near normal ultrastructure group (OR, 0.04; 95% CI, 0.013-0.151; P < 0.01). Heterotaxy was present in 11 of 242 (4.5%) in the outer dynein arm defects group but 0 of 96 in the inner dynein arm defects with microtubular disorganization group (P = 0.038). Conclusion: In primary ciliary dyskinesia, risk of a laterality abnormality differs by ciliary ultrastructural defect. Pathophysiologic mechanisms underlying these differences require further exploration.

Anatomy, embryology, and imaging of situs ambiguous with polysplenia and left IVC.

The situs ambiguous or heterotaxy syndrome is a type of syndrome that involves multiple visceral abnormalities, vascular ones and associated with left isomerism. Malformation of gastroenterologic system includes polysplenia (segmented spleen or multiple splenules), agenesis (partial or complete) of the dorsal pancreas and anomalous of the inferior vena cava implantation. Here, we describe and show the anatomy of a patient with left side inferior vena cava, situs ambiguous (complete common mesentery), polysplenia, and short pancreas. We also discuss about the embryologic process and the implications of these anomalies during gynecologic, digestive, and liver surgeries.

Diagnosis of Dextrocardia with a Pictorial Rendition of Terminology and Diagnosis.

A significant number of patients with dextrocardia and other cardiac malpositions have other congenital heart defects (CHDs). The incidence of CHDs in subjects with cardiac malpositions is significantly greater than that in normal children, and the prevalence varies with the associated visceroatrial situs. The most useful approach to diagnosis is segmental analysis. Firstly, dextroposition should be excluded. In segmental analysis, the visceroatrial situs, ventricular location, status of atrioventricular connections, the great artery relationship, and conotruncal relationship are determined with the use of electrocardiogram (ECG), chest X-ray, and echocardiographic studies, and, when necessary, other imaging studies, including angiography. Following identification of the afore-mentioned segments, the associated defects in the atrial and ventricular septae, valvar and vascular stenosis or atresia may be determined by a review of the historical information, physical examination, and analysis of chest roentgenogram, ECG, and echocardiographic studies. Along the way, a pictorial rendition of the terminology and diagnosis of cardiac malpositions is undertaken.

Heterotaxy syndrome with complex congenital heart disease, facial palsy, and asplenia: A rare newborn finding.

Heterotaxy syndrome is associated with asplenia/polysplenia and complex congenital heart disease. Facial palsy in heterotaxy is very rare. The management is still challenging with a poor prognosis. Proper counseling to the family about the disease course, treatment modalities, and outcomes is essential.

Heterotaxy Syndrome: Discordant Growth.

Heterotaxy syndrome implies a discordance between placement of thoracic organs with respect to abdominal organs. A large number of these have associated congenital heart defects. This syndrome is unique as every patient is different and can have any permutation and combination of symptoms. In our case, the five-year-old male child presented with complaints of abdominal distension, fever, and bluish discoloration of limbs with even mild exertion. Radiological evaluation was diagnosed with a large atrial septal defect, cardiomegaly, partial pulmonary venous circulation, multiple small spleens on the right side of body, a large midline liver, malrotated bowel, inferiorly displaced kidneys, and two hemiazygos veins. The echocardiography and electrocardiogram too were consistent with atrial septal defect and right ventricular strain pattern. The reasons for this highly variable pattern are rooted in the genetically complicated process of lateralization with a strong link to the copy number variations. Due to the variable patterns, it is more efficient to report all the findings utilizing a step-by-step process of commenting on each and every individual organ, instead of classifying them under different categories based on atrial isomerism. This is important as any other way of classification predisposes to a certain bias.

A Rare Case of Recurrent Pneumonia in Heterotaxy Syndrome, Polysplenia/Left Isomerism.

Heterotaxy syndrome (HS) or situs ambiguous refers to the abnormal arrangement of viscera across the body axis, and abnormalities arise depending on the isomerism of the right or left atrial appendage. The cause remains unexplained and is attributed to a combination of genetic mutations and environmental factors. It is a rare condition and may remain undiagnosed for a long time. In this report, we aim to highlight an unusual presentation and aggravation of an infection due to the underlying isomerism of the left atrial appendage. We discuss the case of a female patient who presented with symptoms of fever and cough. The patient underwent prolonged antibiotic treatment, and her recovery was slow. The presence of bilobed lungs, vertical left-bronchus, and polysplenia on CT scan explained the left-sided aspiration pneumonia. The hypofunctioning spleen (polysplenia) caused her to have a weak immunological response, necessitating prolonged antibiotic use. She was followed up over time and had a recurrence of pneumonia within a few months. The condition is associated with high morbidity and mortality, and the role of early diagnosis and reporting to prevent complications is paramount. The recurrent pneumonia observed in the patient also raises questions related to long-term antibiotic use and immunization in the case of polysplenia in this patient population.

Situs Ambiguous Anomaly during Laparoscopic Cholecystectomy in an Adult Female.

Situs anomalies are rare structural defects affecting 0.01% of general population. They present with multisystem structural defects mostly involving cardiovascular, respiratory and GI systems. Situs abnormality with presence of multiple spleen is termed as left atrial isomerism with anatomical and structural differences to its countertype situs ambiguous with asplenia (right atrial isomerism). In this case report, we present an adult case of situs ambiguous anomaly which was diagnosed incidentally during laparoscopic cholecystectomy. The patient had enlarged left lobe of liver, multiple splenules on right side, malrotated small and large gut, interrupted inferior vena cava with azygos continuation, and bilateral bilobed lungs. It is concluded that variations in situs ambiguous cases differ and a single description is not possible. It is crucial to reveal these variations by using imaging modalities and being aware of them prior to surgery and invasive intervention to prevents the possible risks and complications.

99m-Technetium-Labeled Red Blood Cells' Single-Photon Emission Computed Tomography/Computed Tomography in Situs Ambiguous with Polysplenia.

Situs ambiguous or heterotaxy syndrome is defined as the abnormal arrangement of organs and vessels within the body. Herein, we present an 8-year-old girl with growing right-sided suprarenal masses mimicking adrenal tumors. Technetium-99-m-radiolabeled red blood cells' planar images were inconclusive for the diagnosis of splenic tissue in the right side. Single-photon emission computed tomography/computed tomography imaging clearly identified right-sided functioning spleens and confirmed the diagnosis of situs ambiguous with polysplenia.

Situs ambiguous and hepatic vein anomaly: a case report / Situs ambiguous y anomalía de la vena hepática: informe de un caso

SUMMARY: Situs ambiguous is the placement of vessels and organs in the thoracoabdominal space that are anatomically located outside its normal position in a certain order. This condition is a broad definition that includes many variations. In this case report, we reported a patient with Situs ambiguus with an abnormal hepatic vein who was diagnosed incidentally during medical imaging (computed tomography, sonography and MRI study).

RESUMEN: El Situs ambiguous es la colocación de vasos y órganos en el espacio toracoabdominal que anatómicamente se encuentran fuera de su posición normal en un cierto orden. Esta condición es una definición amplia que incluye muchas variaciones. En este reporte de caso, reportamos un paciente con Situs ambiguous con una vena hepática anormal que fue diagnosticado incidentalmente durante un estudio de imagen médica (tomografía computarizada, ecografía y resonancia magnética).

Síndrome de heterotaxia: hallazgos tomográficos / Heterotaxy syndrome: tomographic findings

Resumen El objetivo de este trabajo es caracterizar los aspectos tomográficos relevantes en el síndrome de heterotaxia, mediante cuatro pacientes que ejemplifican los hallazgos más frecuentes en esta patología. Situs solitus es la disposición habitual de los órganos y vasos sanguíneos y situs inversus se refiere a la imagen en espejo del situs solitus. Cuando la disposición de los órganos es indeterminada e impredecible y no se corresponde con el situs solitus ni el situs inversus, estamos frente al situs ambiguus o síndrome de heterotaxia, espectro de anomalías poco frecuente en las relaciones de los órganos toracoabdominales. Puede acompañarse de isomerismo derecho o isomerismo izquierdo. Clasificarlo en dos subgrupos es habitualmente difícil, ya que ninguno de estos tiene hallazgos únicos y patognomónicos, sino que existe amplia superposición. Ambos son de mal pronóstico, en los casos de isomerismo izquierdo un 5-10% llegan a la edad adulta, siendo de peor pronóstico los casos de isomerismo derecho, debido a que presentan inmunodepresión secundaria a la asplenia y cardiopatías congénitas más severas. Se debe analizar cada caso de forma individualizada y detallada para establecer el diagnóstico, determinar la asociación lesional y establecer aquellos pacientes que presenten mayor riesgo de complicaciones.

Abstract The objective of this brief communication is to characterize the relevant tomographic aspects in the heterotaxy syndrome, by means of 4 patients that exemplify the most frequent findings in this pathology. Situs solitus is the usual arrangement of organs and blood vessels and situs inversus refers to the mirror image of situs solitus. When the arrangement of the organs is indeterminate and unpredictable and does not correspond to situs solitus or the situs inversus, we are facing the situs ambiguus or heterotaxy syndrome, abnormal spectrum of anomalies in the relations of the thoracoabdominal organs. It may be accompanied by right isomerism or left isomerism. Attempts to classify it into two subgroups are usually difficult since none of these has unique and pathognomonic findings, but rather there is broad overlap. Both are of poor prognosis, in the cases of left isomerism 5-10% reach adulthood, with a worse prognosis being the cases of right isomerism due to the fact that they have immunodepression secondary to asplenia and more severe congenital cardiopathies. Each case should be analyzed in an individualized and detailed manner to establish the diagnosis, determine the lesional association and establish those patients that present a higher risk of complications.

Asplenia Syndrome in a Neonate: A Case Report.

Asplenia syndrome is a syndrome of right isomerism or attempted bilateral right sidedness. It includes congenital asplenia in association with complex congenital cyanotic heart disease and situs anomalies of the other thoracoabdominal organs. Herein we report a case of asplenia syndrome so as to highlight and refocus attention on the possibility of this rare syndrome that must be considered in a neonate presenting with congenital cyanotic heart disease.

Situs ambiguous, levocardia, right sided stomach, obstructing duodenal web, and intestinal nonrotation: a case report.

When approaching a case with a situs abnormality, using the proper terminology, making a specific diagnosis, and understanding the other often associated abnormalities that need to be excluded are of great importance. We present a case of situs ambiguous in the presence of intestinal nonrotation and an obstructing duodenal web. Our patient initially presented at two days old with bilious emesis and failure to pass meconium after birth. An abdominal radiograph demonstrated an unusual bowel gas pattern, a reversed "double bubble" sign. A subsequent thorough imaging survey was crucial to further characterize our patient's unique anatomy. Overall, our case demonstrates many of the unusual plain radiographic and sonographic findings associated with our patient's situs abnormality and allows for review of situs abnormalities and their significance.

Cardiac and Non-Cardiac Abnormalities in Heterotaxy Syndrome.

Thoraco-abdominal viscera have unique morphological asymmetry, unlike the body's external organs. Heterotaxy syndrome is a disorder in which there is a loss of normal left to right asymmetry of thoraco-abdominal viscera and their naturally proscribed spatial relationship. It has multiple anatomical alterations, culminating into physiological and hemodynamic consequences. It is divided into two groups on the basis of morphology of the two atrial appendages. These subgroups are - 1) Isomerism of right atrial appendage (asplenia syndrome); 2) Isomerism of left atrial appendage (polysplenia syndrome); Patients from group I, usually have severe cardiac malformations and present early. They may have duct dependent lesions and eventually may undergo Fontan surgery. However, extracardiac anomalies are more common in group II. All the patients must be evaluated in detail to rule out anomalies like gut-malrotation. Patients must be provided with special care for their susceptibility to infection due to absence of spleen or presence of splenic malfunction. Majority of these patients may have genetic link and may present in families. Hence, genetic evaluation is necessary before assuming long term outcome.

Heterotaxy Polysplenia Syndrome In An Adult With Unique Vascular Anomalies: Case Report With Review Of Literature.

The pattern of anatomical organization of the thoraco-abdominal visceral and vascular structures which is not the expected normal arrangement, is called as situs ambiguous or heterotaxy syndrome. Patients with heterotaxy syndrome exhibit a wide spectrum of anatomical variations involving thoraco-abdominal structures. We present here an incidental finding of heterotaxy syndrome associated with unique vascular anomalies in a 35 year old male patient evaluated initially for nephrolithiasis by ultrasonography, and intravenous pyelography. Further evaluation by multidetector row computed tomography showed bilateral bilobed lungs with hyparterial bronchi, cardiac apex to the left, five branches from left-sided aortic arch with retroesophageal right subclavian artery, interrupted inferior vena cava with azygos continuation, left renal vein continuing as hemiazygos vein and replaced common hepatic artery arising from the superior mesenteric artery. Other vascular anomalies include right internal iliac vein joining the left common iliac vein and precaval course of the single main right renal artery. Anomalies involving abdominal organs include right-sided stomach, midline liver, multiple splenules (polysplenia) in right upper quadrant of abdomen, short truncated pancreas, intestinal malrotation, inversion of superior mesenteric vessels and a preduodenal portal vein. To the best of our knowledge this is the first report of association of left renal vein continuing as hemiazygos vein, precaval right renal artery and anomalous branching pattern of aortic arch with heterotaxy syndrome.

Incidentally detected situs ambiguous in adults.

Situs ambiguous is rare congenital anomaly in adults. In 2 adult patients who admitted for different cardiac problems, situs ambiguous with polysplenia was detected. A 42-year-old male admitted for radio frequent catheter ablation of atrial fibrillation, and he had left-sided inferior vena cava (IVC), hepatic segment of IVC interruption with hemiazygos continuation, multiple spleens and intestinal malrotation. And in a 52-year-old female case who was hospitalized due to infective endocarditis after implanting pacemaker for sick sinus syndrome, multiple spleens, left-sided stomach, bilateral liver with midline gallbladder, and left-sided IVC were found. Those findings were consistent with situs ambiguous with polysplenia, but their features were distinctive.