Asplenia syndrome, also known as right atrial isomerism is a subcategory of heterotaxy. It involves multiple malformations and abnormal location of organs, characteristically including congenital cardiac lesions and the absence of a spleen.
Asplenia syndrome (AS) is a condition that results from failure of normal rotation of thoracic and abdominal structures during embryogenesis. It is often detected soon after birth and constitutes 1% of newborns diagnosed with congenital heart disease. AS is a subtype of heterotaxy, also referred to as right atrial isomerism, and falls within a wide range of lateralization disorders that have variable abnormalities and presentations . In AS, the left side of the body is essentially a copy of the right-hand side, hence the characteristic absence of the spleen, which is normally located on the left. Although hereditary occurrences have been reported, some following an X-linked pattern, most cases of AS are isolated, and the etiology is unknown.
The common signs associated with AS are congenital cardiac malformations, which are often cyanotic and are the most frequent cause of symptoms and death. They usually consist of transposition of great vessels, pulmonary stenosis (and other valvular diseases), and total anomalous pulmonary venous connection (TAPVC).
Furthermore, AS is associated with numerous defects in the chest and abdominal cavities, the most prominent and clinically relevant of these being the lack of development of a spleen. Individuals with asplenia have a weakened immune system and are more susceptible to severe life-threatening infections, particularly those mediated by encapsulated organisms  . This risk exists throughout their entire lives. Other abnormalities reported include a midline or transverse liver, gall bladder and pancreas malformations, three lobes in both lungs, as well as an inferior vena cava that is located anterior to the aorta. AS carries a high mortality rate as over 85% of children born with AS die before the age of one year  . It is thought that those who survive beyond childhood may have milder manifestations and complications.
Entire Body System
Atrial Septal Defect
septal defect, patent ductus arteriosus, bilateral superior venae cavae, and inferior vena cava draining into the left-sided atrium. [ncbi.nlm.nih.gov]
The most common associated cardiovascular anomalies in polysplenia are noncyanotic congenital heart defects, including atrial septal defect, endocardial cushion defects, partial anomalous pulmonary venous return, and up to 50% of cases are associated [metealpaslan.com]
Pulmonary Valve Stenosis
Classically, Heterotaxy comprises of: Cardiac looping malformations – commonly Fallot’s Tetralogy, Transposition of the Great Vessels, Pulmonary Valve Stenosis, and ventricular and atrial septal defects. [chdbabies.com]
[…] unable to avoid public transport (for example, if you need to get to hospital for treatment or an appointment), wash your hands after every trip, use the antiseptic hand gel dispensers in the hospital regularly, cover your nose and mouth if you sneeze or cough [dontforgetaboutflu.co.uk]
Those with asplenia are also cautioned to start a full-dose course of antibiotics at the first onset of an upper or lower respiratory tract infection (for example, sore throat or cough), or at the onset of any fever. [en.wikipedia.org]
The diagnosis of AS depends on a combination of history, physical examination and imaging findings. Features known to be typical in AS are used to guide the choice of investigations, which focus on specific systems or organs. These may include:
- Testing for nucleic acids known as Howell-Jolly bodies, which may be present in the red blood cells as a sign of splenic pathology.
- Electrocardiogram (ECG): This is useful in the detection of arrhythmias and other abnormalities in cardiac function
- Echocardiogram: This is a non-invasive imaging technique used to visualize and confirm structural defects of the heart .
- Prenatal ultrasound: It is possible to diagnose AS before birth, as ultrasound can be used to identify cardiac abnormalities and asplenia .
- Computerized tomography (CT) scan and CT angiography: These accurately detail the nature of malformations, as this information is needed for patient care and treatment .
- Magnetic resonance imaging (MRI) scan: MRI is also useful in defining the relationship between soft tissue structures.
Abstract Asplenia was suspected in one patient with combined immunodeficiency syndrome and 5 with congenital cardiac anomalies who had Howell-Jolly bodies on peripheral blood smears. 99mTc-sulfur colloid scans were equivocal for absence of the spleen. [ncbi.nlm.nih.gov]
These may include: Testing for nucleic acids known as Howell-Jolly bodies, which may be present in the red blood cells as a sign of splenic pathology. [symptoma.com]
Relevant laboratory investigations including peripheral blood smear revealed Howell-Jolly bodies. Parathormone and electrolytes were normal. Quantitative measurements of major immunoglobulin classes and T lymphocyte subpopulations were normal. [endocrine-abstracts.org]
This paper draws attention to the prophylactic treatment of gastric malfixation in the AS through the presentation of two cases in which gastropexy was performed. [ncbi.nlm.nih.gov]
Computerized tomography (CT) scan and CT angiography: These accurately detail the nature of malformations, as this information is needed for patient care and treatment. [symptoma.com]
This era was followed by improved environmental factors which operate to produce methods of medical treatment, introduction congenital cardiac malformations. [books.google.com]
We have stressed the importance of early recognition of mendelian disorders with associated cardiac malformations to provide meaningful counseling regarding prognosis, medical management, and risk of recurrence. [ncbi.nlm.nih.gov]
Coverage of congenital heart abnormalities includes how the conditions look on scans, which scanning views and modalities to use, differential diagnosis, prognosis, and treatment. [books.google.com]
A review of cardiac and non-cardiac malforma tions in 60 cases with special reference to diagnosis and prognosis. Br Heart J 1975 ; 37 : 840 – 852. 11. Sapire, DW, Ho, SY, Anderson, RH, Rigby, ML. Diagnosis and significance of atrial isomerism. [cambridge.org]
A brief review of the various hereditary patterns of visceral situs abnormalities suggests that, at least in some cases, the asplenia and polysplenia syndromes are etiologically and pathogenetically interrelated. [ncbi.nlm.nih.gov]
Although hereditary occurrences have been reported, some following an X-linked pattern, most cases of AS are isolated, and the etiology is unknown. [symptoma.com]
Their etiology is not precisely century with the first clinical recognition of known, so we have included chapters that dis symptoms and patterns for diagnosis of car cuss many aspects of congenital cardiac mal diovascular diseases. [books.google.com]
Etiology Acquired asplenia Anatomic asplenia : due to splenectomy, which may be indicated in Functional asplenia Autosplenectomy: sickle cell anemia Splenic infarction ( splenic artery thrombosis ) Tumor infiltration Congenital asplenia (very rare) References [amboss.com]
Cheng, Department of Epidemiology and Preventive Medicine, Monash University, Commercial Road, Melbourne, VIC 3004, Australia. (Email: [email protected] ) References Hide All 1. Di Sabatino, A, Carsetti, R, Corazza, GR. [cambridge.org]
To review the epidemiology and clinical course of invasive S. pneumoniae infections in children with asplenia before the release of the conjugate pneumococcal vaccine. [journals.lww.com]
Clinical and Epidemiological Study 40.1 (2012): 35-39 Yapp, Alvin. "Infection Outcomes in Splenectomized Patients." International Society for Infectious Diseases 13 (2009): 696-700. [nuemblog.com]
Epidemiology The exact incidence is not known. Asplenia is present in about 3% of neonates with structural heart disease. Isolated asplenia is most often recognized at autopsy. [unboundmedicine.com]
Pathophysiology: High Risk Organisms IV. [fpnotebook.com]
Pathophysiology The spleen is a major component of the reticuloendothelial system; it is important both for antibody synthesis and for clearance of opsonized organisms by phagocytosis. [unboundmedicine.com]
The pathophysiology of asplenia also varies depending on the underlying etiology and comorbid conditions. [ncbi.nlm.nih.gov]
Severe reduction of pulmonary blood flow secondary to pulmonary stenosis or atresia in such patients may prevent the usual radiographic appearance of pulmonary oedema. [ncbi.nlm.nih.gov]
Doctors should encourage routine medical examination for their patients which could help identify this anomaly, thereby preventing wrong diagnosis and possibly death due to delay in management. Key words: Dextrocardia; heterotaxy; asplenia syndrome. [scopemed.org]
Management of this abnormality include surgical correction and prevention of infection with vaccination and antibiotic prophylaxis due to asplenia. [jmums.mazums.ac.ir]
Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. الصفحة 332 - Crane JP, LeFevre ML, Winborn RC, et al. [books.google.com]
Postsplenectomy infection – strategies for prevention in general practice. Australian Family Physician 2010 ; 39 : 383 – 386. 3. Spelman, D, et al. Guidelines for the prevention of sepsis in asplenic and hyposplenic patients. [cambridge.org]
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