What is Asplenia?
Asplenia is a medical condition where there is absence of normal spleen function. The term Asplenia literally means an absent spleen. However, the spleen may not be physically absent in most of the patients and rather there is underdevelopment of the spleen due to which the function of the spleen is not completely reached. Asplenia carries serious risks of infection and needs careful management. The spleen is one of the most vital organs of the body and its function is filtering the blood and maintaining the immune system. Most of the patients with Asplenia have multi-organ involvement.
Fortunately the incidence rate for asplenia is low. Asplenia is seen in men more than women. According to studies, about 1% to 3% of children who have congenital heart defects also have asplenia.
What are the Causes of Asplenia?
Congenital /Genetic Causes of Asplenia: It is thought that there is genetic association with asplenia. However, there is no sufficient proof of this. It is also assumed that non-working genes can lead to asplenia. It is also thought that parents who are somehow related can possibly pass the autosomal recessive gene to one of their children. There has been no clear proof of this; however, some patients are thought to acquire asplenia in this manner. Congenital asplenia is a rare occurrence. There are two different types of genetic disorders: isolated congenital asplenia and heterotaxy syndrome.
Acquired Causes of Asplenia: There are various causes of Acquired Asplenia:
- Asplenia caused by splenectomy done due to splenic rupture as a result of tumor or injury/trauma.
- Asplenia caused by splenectomy done with the aim of interfering with the function of spleen for treating diseases, such as thalassemia, idiopathic thrombocytopenic purpura and spherocytosis because the spleen's normal function exacerbates these diseases.
- Asplenia caused by underlying diseases such as sickle-cell disease, which destroy the spleen. This is also termed as autosplenectomy.
- Patients with functional asplenia are treated as asplenic. Functional asplenia is a condition when splenic tissue is present, but it does not function well, e.g. sickle-cell disease.
What are the Symptoms of Asplenia?
Asplenia affects multiple organs of the body. Due to the absence of spleen or functioning of the spleen, the following symptoms or manifestation are seen in patients with Asplenia:
Increased Risk of Infections: As spleen's function is not met, the immune system gets affected which makes the patient more prone to infections.
Problems with Digestive Tract: Patients with asplenia are at an increased risk for having digestive tract problems due to intestinal malrotation where there is rotation of the midgut. Obstruction is the commonest problem of asplenia with digestive tract problems and this can be a life threatening situation requiring emergent surgical intervention.
Malpositioning of Liver and Stomach: With the absence of spleen, there will be significant changes in the location of the liver and stomach. The normal location of the stomach is in the central abdominal quadrant and the absence of the spleen causes it to be mal-positioned, which can result in twisting. Also, the liver which is normally located at the upper right quadrant of the abdomen tends to move to the central part of the body and can occupy a larger space in the opposite side. These may lead to obstruction which hinders proper digestion and blood circulation to stomach.
Heart Problems: Heart diseases tend to develop in children with congenital asplenia. This leads to respiratory problems and cyanosis. The symptoms in children suffering with congenital heart disease are similar to symptoms in children suffering from heart problems developing from asplenia. Patients having asplenia-induced heart problems will commonly have abnormal pulmonary venous return. Due to this problem, the patient will have difficulties with respiration and proper oxygenation of body. Another anomaly which develops as an asplenia-induced heart problem is atrial septal defect where there is distribution of less oxygenated blood to the body instead of oxygenated blood.
Lung Problems: Patients with asplenia will have 3 lobes in the left lung instead of 2 lobes.
What are the Complications of Asplenia?
Asplenia is a type of immunodeficiency which leads to increased risk of infection and sepsis caused by polysaccharide encapsulated bacteria. This can lead to devastating post splenectomy infection which can become life threatening in a few hours. Patients are especially at increased risk from Haemophilus influenzae, Streptococcus pneumoniae and meningococcal. There is increased platelet counts is patients with asplenia.
How is Asplenia Diagnosed?
Imaging studies are done to confirm the diagnosis of asplenia. MRI scan is extremely useful in detecting any problems with other organs of the body along with checking their positioning. Echocardiogram is done to detect problems of the cardiovascular system which occur as a result of asplenia. Chest x-ray helps in ascertaining the position of the heart and to look for problems with the lungs. Ultrasound is done to detect any probable malformation and location of the organs which can be potentially affected. A screening test is done to detect Heinz and Howell-Jolly bodies in the blood as the presence of these bodies is indicative of asplenia.
How is Asplenia Treated?
The aim of treatment for asplenia is to alleviate or manage the symptoms of asplenia:
Surgery: Surgery may be done if the patient has heart defect induced by asplenia. Surgery is also done if there is an intestinal obstruction present.
Vaccinations: Proper vaccinations should be given to the patient to protect them against any infections, as asplenia makes the patient prone to infection due to nonfunctioning of the spleen.
Patients who are undergoing splenectomy should take the following vaccinations before the surgery: Pneumococcal vaccines, Haemophilus influenzae type b vaccine, Meningococcal conjugate vaccine and influenza vaccine.
Antibiotics: Antibiotics are given to the patient if there is already an infection present to prevent further exacerbation. Antibiotics are also given prophylactically to prevent the development of infections in patients with asplenia or after splenectomy.
- It is important that the patient with asplenia or without a functioning spleen should carry an alert card or wear a warning bracelet so that if he/she falls sick then emergent treatment is started to prevent fatal outcome.
- Antibiotic prophylaxis should be given to patients with asplenia before any dental and surgical procedures.
- Patients with asplenia should get themselves checked for tick bites as they are at increased risk for any tick-borne infection.
- In case of any animal bites, patients should be given adequate antibiotic, even if the bite is minor.
What is the Prognosis & Life Span of Patients with Asplenia?
If Asplenia is not treated or managed properly, then the prognosis is very poor. About 80% of patients with asplenia have a life expectancy of about 1 year. The poor prognosis is due to the involvement of multiple organs, especially the heart. With proper treatment and management of Asplenia, the prognosis is relatively better with improved life expectancy.