Thrombocytosis in asplenia syndrome with congenital heart disease: A previously unrecognized risk factor for thromboembolism

Incidental Finding of Heterotaxy Syndrome in a Patient With Pulmonary Embolism: A Case Report and Concise Review

Heterotaxy syndrome, also called atrial isomerism, is a rare congenital condition in which the internal organs are abnormally arranged across the left-right axis of the body. It is classified into polysplenia syndrome or left atrial isomerism and asplenia syndrome or right atrial isomerism. It is associated with high morbidity and mortality due to the severity of cardiac anomalies. It is important to be aware of the syndrome findings as they can be incidentally found on imaging in adults. Here, we report a case of a 33-year-old female who presented with worsening shortness of breath, found to have a pulmonary embolism, and heterotaxy was incidentally identified on her imaging. A concise review follows.

The multisystem nature of isomerism: left isomerism complicated by Abernethy malformation and portopulmonary hypertension

Isomerism, also referred to as "heterotaxy" is a complex set of anatomic and functional perturbations. One of the most obvious manifestations of isomerism is the disturbance of organ arrangement, such that the thoracic organs are no longer asymmetric on the left and right. We report the case of a 14-year-old female in whom exercise-induced dyspnea led to a late diagnosis of left isomerism complicated by Abernethy malformation and portopulmonary hypertension. A comprehensive evaluation revealed two anatomic left lungs and hyparterial bronchi, bilateral left atria, an interrupted inferior caval vein with azygos continuation, multiple spleens, sinus node dysfunction, hepatic hypertrophy with focal nodular hyperplasia, and absence of the portal vein. Pulmonary vasodilator therapy was initiated resulting in clinical improvement. This case exhibits unique features including a late diagnosis of isomerism with Abernethy malformation and portopulmonary hypertension. The patient's presentation, medical workup, and future treatment emphasise the importance of multidisciplinary care in children with complex multisystem disease. We review the multiple cardiac and extracardiac manifestations of isomerism.

Incidence and Timing of Thrombosis After the Norwood Procedure in the Single-Ventricle Reconstruction Trial

Background Thrombosis is common in infants undergoing staged surgeries for single-ventricle congenital heart disease. The reported incidence and timing of thrombosis varies widely, making it difficult to understand the burden of thrombosis and develop approaches for prevention. We aimed to determine the timing and cumulative incidence of thrombosis following the stage I Norwood procedure and identify clinical characteristics associated with thrombosis. Methods and Results We analyzed data from the Pediatric Heart Network Single Ventricle Reconstruction trial from 2005 to 2009 and identified infants with first-time thrombotic events. In 549 infants, the cumulative incidence of thrombosis was 21.2% (n=57) from stage I through stage II. Most events occurred during stage I (n=35/57, 65%), with a median time to thrombosis of 15 days. We used a Cox proportional hazards model to estimate the association of clinical variables with thrombosis. After adjusting for baseline variables, boys had a higher hazard of thrombosis (adjusted hazard ratio [HR], 2.69; 95% CI, 1.44-5.05; P=0.002), non-hypoplastic left heart syndrome cardiac anatomy was associated with a higher early hazard of thrombosis (adjusted HR, 3.93; 95% CI, 1.89-8.17; P<0.001), and longer cardiopulmonary bypass time was also associated with thrombosis (per 10-minute increase, adjusted HR, 1.07; 95% CI, 1.01-1.12; P=0.02). Lower oxygen saturation after the Norwood procedure increased the hazard for thrombosis in the unadjusted model (HR, 1.08; 95% CI, 1.02-1.14; P=0.011). Conclusions Thrombosis affects 1 in 5 infants through Stage II discharge, with most events occurring during stage I. Male sex, non-hypoplastic left heart syndrome anatomy, longer cardiopulmonary bypass time, and lower stage I oxygen saturation were associated with thrombosis.

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.

Venous Thromboembolism in Special Populations: Preexisting Cardiopulmonary Disease, Cirrhosis, End-Stage Renal Disease, and Asplenia

Venous thromboembolism (VTE) is a common cause of morbidity and mortality. Presence of preexisting conditions, such as cardiopulmonary diseases, cirrhosis, renal dysfunction, and asplenia, commonly occurs in VTE patients. Moreover, these conditions often are risk factors for developing VTE. These preexisting conditions make VTE diagnosis and treatment challenging and worsen outcomes. Current guidelines do not include detailed features in the diagnosis and management of patients with preexisting conditions. This review discusses presence of VTE in patients with preexisting cardiopulmonary diseases, cirrhosis, renal dysfunction, and asplenia.

Factors influencing bacteraemia in patients with isomerism and CHD: the effects of functional splenic status and antibiotic prophylaxis

BACKGROUND

"Heterotaxy syndrome", best segregated as isomerism, is characterised by laterality defects of the thoraco-abdominal organs, causing functional impairment. In particular, the spleen is frequently affected, increasing susceptibility to bacteraemia. This study explored factors that may increase the risk of bacteraemia in patients with isomerism.

METHODS

We identified patients with CHD and isomerism. Review of outpatient, inpatient, and surgical records was conducted to collect data and determine trends in the cohort. A Cox regression analysis was conducted to determine factors influencing freedom from bacteraemia (Fig 1).

RESULTS

We identified 83 patients with CHD and isomerism - 17 (20%) who had documented episodes of bacteraemia with a total of 21 episodes. A majority (86%) were nosocomial. The median age at the time of bacteraemia was 4 months. Although splenic anatomy did appear to influence the risk of bacteraemia in univariate analysis, this significance was lost with multivariate analysis. None of the other factors was significantly associated in either univariate or multivariate analysis.

CONCLUSION

Specific factors such as splenic anatomy, atrial appendage isomerism, and antibiotic prophylaxis status are not significantly associated with the risk of bacteraemia in patients with CHD and isomerism. Nosocomial infections represent a majority of bacteraemia in these patients.

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.

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.

Thrombocytosis in the Setting of Isomerism and a Functionally Univentricular Heart

Introduction

Bodily isomerism, also known as heterotaxy, is a unique entity in which there is mirror imagery in various organ systems. Those with isomerism will often have congenital malformations of the heart requiring functionally univentricular palliation. Anecdotally, thrombocytosis has been noted with higher frequency in patients with isomerism. This study aimed to determine the prevalence of thrombocytosis at different stages and identify independent predictors of thrombocytosis.

Methods

We identified patients with isomerism and a functionally univentricular heart who received care at our institution between January 1998 and January 2014. Clinical data regarding these patients was collected via chart review. Platelet counts were collected before initial surgical palliation, the day prior to second surgical palliation, and the day prior to the third surgical palliation. Platelet counts from the first postoperative day following all three surgical palliations was also collected. Mean platelet counts were compared between consecutive stages as well as to the initial platelet count. The frequency of thrombocytosis was also calculated at each point with a binomial logistic regression conducted to determine independent risk factors of thrombocytosis at each time point.

Results

A total of 57 patients were included in the analysis. The mean platelet count before initial surgical palliation was 349.21 x 10⁹/L and decreased with age. Thrombocytosis was noted in 15.8% prior to initial surgical palliation and 23.6% prior to second surgical palliation. Thrombocytosis was no longer noted after second surgical palliation. No independent risk factors for thrombocytosis were identified.

Conclusion

Thrombocytosis is not infrequent during the first year of life in those with isomerism. It is important to be vigilant of platelet counts in this population as thrombocytosis may lead to increased thromboembolic events, particularly in the setting of a Blalock-Taussig shunt. Thrombocytosis nearly always resolves after the second surgical palliation.

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.

Reference ranges of fetal spleen biometric parameters and volume assessed by three-dimensional ultrasound and their applicability in spleen malformations

AIM

The aims of this article are to establish three-dimensional ultrasonographic nomograms of normal fetal spleen size and to evaluate the clinical application value.

METHODS

An observational, cross-sectional study was performed on 455 women with a normal singleton pregnancy between 18 and 38 weeks' gestational age (GA). Fetal spleen volume was measured using three-dimensional ultrasound equipped with virtual organ computer-aided analysis, and biometric parameters were assessed in multiplanar mode to create reference ranges to GA. Thirty cases were randomly selected to conduct reliability analyses via intraobserver and interobserver ultrasonographic measurement. Moreover, 50 cases of suspected splenic malformations were evaluated by the newly established nomograms and followed up subsequently.

RESULTS

Using regression formulas, we found that fetal spleen size increased with GA. We observed strong reliability in intraobserver and interobserver volume measurements with intraclass correlation coefficients of 0.994 and 0.962. Bland-Altman analyses showed narrow limits of agreement [intraobserver: (-3.2 to 3.5)%; interobserver: (-3.2 to 4.3)%]. Of the 50 cases with suspected splenic malformations, six cases of splenomegaly and one case of splenic cyst were diagnosed.

CONCLUSION

Three-dimensional ultrasound nomograms of normal fetal spleen size across a range of GA have a strong diagnostic value. Volume measurements with good reliability were optimal in clinical practice.