What is Splenic Infarction?
The spleen is a lymphatic organ of our body situated in the upper left abdominal quadrant. The function of the spleen is filtering and storing the red blood cells, production of white blood cells for immunity and removing microorganisms, such as bacteria. If there is any interruption of the blood flow or blood circulation to the spleen, such as blockage in the splenic artery or one of its branches, then it leads to a condition known as splenic infarction (death of the tissue from oxygen deprivation). The splenic infarction can be partial or complete. The area of the spleen affected by loss of blood supply or essentially the regions where the tissue death in the spleen has occurred is known as splenic infarct. The interruption in the blood supply to the spleen can be caused by an object, such as a piece of plaque or blood clot. It could also be due to infection, trauma or certain diseases. The regions of the spleen which are affected from lack of blood supply die as they do not receive sufficient blood and oxygen resulting in splenic infarction or formation of splenic infarct. Some of the serious complications of splenic infarction are splenic abscess and splenic rupture.
Splenic infarct forms when there is deprivation of blood flow to one or more small areas within the spleen. As mentioned before the blockage in the blood circulation can be due to clots, conditions such as infected heart valves, artificial heart valves, hypercoagulable states, trauma to the spleen, cancer and its metastasis.
What Causes Splenic Infarction?
- The cause of Splenic Infarction is decreased blood circulation to the spleen due to blockage in the splenic artery or any of its branches. The blockage could be due to a clot, mass, infection or trauma.
- There are many factors which increase the tendency for formation of clot, such as infections like cytomegalovirus infection, infectious mononucleosis, malaria, or babesiosis, inherited clotting disorders, such as antiphospholipid syndrome, thrombophilia, malignancies such as pancreatic cancer or metastasis of the cancer, or it can be due to a combination of all the above factors.
- There are some conditions like atrial fibrillation, having a prosthetic mitral valve, endocarditis, patent foramen ovale, paradoxical emboli from right heart, cholesterol embolism, infected thoracic aortic graft, left ventricular mural thrombus after a myocardial infarct and mycobacterial infections associated with HIV, where there is clotting of the blood in one part of the circulatory system and the blood clot then dislodges and travels to another part of the body, which can also include spleen, leading to formation of a splenic infarct or splenic infarction.
- Benign hematological disorders, such as hypercoagulable states , use of oral contraceptives, lupus anticoagulant, idiopathic venous thrombosis, erythropoietin therapy, sickle hemoglobinopathies and polycythemia vera can also cause splenic infarction.
- Some hematological disorders such as myeloproliferative disorders with associated splenomegaly can also cause splenic infarct. Malignant hematological disorders, such as lymphoma, leukemia or myelofibrosis can also cause splenic infarction.
- Other medical causes of splenomegaly such as Gaucher's disease can also predispose or increase the risk of having splenic infarction.
- Sickle cell crisis in individuals with sickle cell anemia can also cause splenic infarction. This condition is characterized by splenomegaly and a tendency towards clot formation. There can be repeated splenic infarctions in sickle cell disease resulting in a non-functioning spleen (autosplenectomy).
- Factors which directly compromise the splenic artery can cause splenic infarction. Some of these factors include aortic dissection, abdominal traumas, torsion of the splenic artery and compression of splenic artery due to tumor.
- Complication of vascular procedures can also cause splenic infarction.
- Diffuse intravascular coagulation or vasculitis can also cause splenic infarction.
- Certain medications, such as vasoconstrictors, increase the predisposition to thrombosis or vasospasm leading to splenic infarction.
- There are some conditions, which are related to splenic infarction, such as granulomatosis with polyangiitis.
- Collagen vascular diseases or autoimmune diseases can also lead to splenic infarction.
- Other medical conditions such as splenic vein thrombosis, amyloidosis, pancreatitis, sarcoidosis, acute respiratory distress syndrome (ARDS), pancreatic cancer and postpartum toxic shock syndrome can also lead to splenic infarction.
- Surgical procedures, such as liver transplant and pancreatectomy, can also lead to splenic infarction.
Signs & Symptoms of Splenic Infarction
Symptoms depend on the cause of the splenic infarction and on the extent and severity of the damage to the spleen. In some cases, patient does not have any symptoms of splenic infarction until it has reached a severe stage. Some of the common symptoms of splenic infarction include:
- Severe pain and tenderness in the left upper abdomen is the most common symptom.
- The pain can radiate to the left shoulder.
- Pain in the left flank.
- Fever with chills.
- Nausea and vomiting.
- Pain in the lower left chest.
- Hypotension and tachycardia can be an indication of impending hemorrhagic shock due to splenic rupture.
- Abdominal distension.
- Changes in the mental status; can be due to septic shock occurring as a result of splenic abscess, if the cause of the splenic infarction is bacteria.
Complications of Splenic Infarction
Splenic infarction can lead to serious complications, such as splenic abscess and splenic rupture which are described as below:
Splenic Abscess: Splenic infarction caused by bacteria can lead to splenic abscess. Symptoms of splenic abscess comprise of acute pain in the upper abdomen, radiating shoulder pain, upper abdominal tenderness, pain in the left lower chest, vomiting and fever. If splenic abscess is left untreated, then it can result in sepsis due to the bacteria entering the bloodstream and spreading to other organs and tissues of the body. If sepsis is not treated then, it can lead to septic shock where the patient exhibits symptoms, such as tachycardia, severe hypotension and changes in mental status.
Splenic Rupture: In some cases, splenic infarction can cause rupture of the spleen and hemorrhage. Diagnosis of non-traumatic type of splenic rupture is difficult, as the symptoms of splenic rupture are similar to appendicitis, heart attack or acute pancreatitis. The most common symptom of splenic rupture is again pain in the left upper abdomen, which can radiate towards the left shoulder. Some of the common signs are tachycardia and hypotension, which can be an indication of potential hemorrhagic shock. Other than this, patient can also have abdominal distension with presence of mass in the left upper abdomen.
Investigations to Diagnose Splenic Infarction
- Medical history & physical exam of the patient is taken.
- CT scan of the abdomen is the common investigation done to confirm the diagnosis.
- Echocardiogram or a heart murmur can reveal if the clot has traveled from the heart.
- Complete blood count (CBC).
- Comprehensive metabolic panel (CMP).
- Magnetic resonance imaging (MRI).
How is Splenic Infarction Treated?
The aim of treatment of Splenic Infarction is treating the underlying cause and relieving the pain. There is no specific treatment for splenic infarction. Initially, the patient is put under observation. Painkillers and NSAIDs such as ibuprofen and naproxen are given to relieve pain.
Surgery, i.e. splenectomy, is done only when required, such as when there are complications only, as surgically removing the spleen greatly increases the risk of serious post-splenectomy infections.
Patients with non-functioning spleen need to undergo evaluation for vaccination against haemophilus, pneumococcus and meningococcal bacteria.
As mentioned above, complications of splenic infarction include a ruptured spleen, splenic abscess, hemorrhage or formation of pseudocyst . Splenectomy is also needed for persistent pseudocysts or if there multiple abscesses in the spleen as it has a high risk of rupture.
Sometimes patients having splenic infarction can delay the treatment due to the initial absence of symptoms or if the symptoms are mild. If patient suffers from a condition which makes them more prone to any type of infarction, including splenic infarction, then they should immediately get treatment done, especially if they are also having symptoms, such as tenderness in the left upper abdomen or left upper abdominal pain which also radiates to the left shoulder.
If fever is also present along with these symptoms, then it indicates a splenic abscess. If there are signs of hemorrhagic shock with these symptoms then it indicates rupture of the spleen. All these conditions are fatal and can result in death, so it is imperative that the patient seeks immediate medical attention.
Therapeutic Splenic Infarction
Splenic infarction can be induced for medical purposes, such as for treating conditions like splenic injury or portal hypertension. Medical induction of Splenic Infarction can also be done before doing splenectomy for preventing loss of blood.