[4] Splenic Infarct Flashcards
What causes a splenic infarct?
Occlusion of the splenic artery, or one of its branches, resulting in tissue necrosis
What is the cause of a splenic infarct?
It is caused by many separate pathophysiological processes
What provides the blood supply to the spleen?
The splenic artery and the short gastric arteries
Where does the splenic artery come from?
Coeliac axis
Where do the short gastric arteries come from?
The left gastroepiploic artery
What is the result of the spleen being supplied with blood from multiple arteries?
Infarction is often not complete due to collateral circulation
Are splenic infarctions common?
No, they are rare events
Give an example of a condition that has a high incidence of splenic infarcts?
Chronic myelogenous leukaemia (72%)
Are splenic infarcts always symptomatic?
No
What are the most common causes of splenic infarcts?
Haemotological disease or thromboembolism
What is a more common cause of splenic embolism, haemotological disorders or embolic disorders?
Haemotological disorders
What haemotoloical disorders can cause splenic infarction?
Leukaemia or lymphoma Myelofibrosis Sickle Cell Disease Chronic Myeloid Leukaemia Polycythaemia Rubra Vera Hypercoaguable states
What embolic disorders can lead to splenic infarction?
Endocarditis
AF
Infected aneurysm grafts
Post-MI mural thrombus
What are some rarer causes of splenic infarction?
Vasculitis
Trauma
Collagen tissue defects
Surgery
What kinds of trauma can cause splenic infarction?
Blunt trauma, or torsion of a ‘wandering’ splenic artery
What surgeries can cause splenic infarction?
Pancreatectomy
Liver transplantation
How does haematological disease cause splenic infarction?
Through congestion of the splenic circulation by abnormal cells
What often confounds splenic infarction caused by haematological disease in conditions such as CML or myelofibrosis?
Anaemia and splenomegaly
How will symptomatic splenic infarct patients classically present?
Left upper quadrant abdominal pain, radiating to the left shoulder (Kehr’s sign)
What are the less common symptoms of splenic infarcts?
Fever
Nausea and vomiting
How can splenic infarcts be diagnosed if they are asymptomatic?
Purely by imaging or laparotomy/laparoscopy
What is commonly found on examination with splenic infarcts?
LUQ tenderness
Other signs may be present depending on any complications that may have developed
What are the differential diagnoses of splenic infarcts?
The most important differentials to consider for LUQ pain include;
Peptic ulcer disease
Pyelonephritis or ureteric colid
Left sided basal pneumonia
What is the gold standard investigation for suspected splenic infarction?
CT abdominal scan with IV contrast
What routine bloods should be performed in suspected splenic infarction?
FBC
U&E
LFTs
Coagulation screen
When are bloods particularly useful for the diagnosis of splenic infarction?
If a haemotological or thromboembnolic cause is suspected
What may be found on bloods with splenic infarction?
WCC is high in around half of cases
Raised d-dimer levels may aid diagnosis
How does a splenic infarction appear on CT scanning with contrast?
As a segmental wedge of hypoattenuated tissue, with the apex of the wedge pointing to the hilum of the spleen from the segmental branching of the splenic artery
Why does CT scanning with contrast produce a hypoattenuated wedge on CT?
Because the IV contrast cannot reach the infarcted area
What will be shown on CT with contrast if the splenic artery, rather than one of its segmental branches, is affected?
The entire spleen will be hypoattenuated
How are most cases of splenic infarction followed up after treatment?
With repeat CT scanning
What may be shown on repeat CT scanning with contrast following treatment for splenic infarction?
Either full resolution, fibrosis of the original infarct, or liquefaction of the affected region
Are there any specific treatments for splenic infarcts?
No
What is involved in the management of splenic infarct?
Regular monitoring, ensuring haemodynamic stability, with appropriate analgesia and IV hydration prescribed
What do most cases of splenic infarct warrant in terms of management?
Suitable management of the underlying condition, in order to minimise future risk
Why is it important to identify the cause of splenic infarction?
As it may require the involvement of a haematologist and an ECHO scan, as well as consideration for long-term anticoagulation
Why should splenectomy be avoided following splenic infarction?
Due to risks of overwhelming post-splenectomy infection (OPSI) syndrome
When might splenectomy be unavoidable in splenic infarction?
If complications develop, or symptoms persist
How long should a splenectomy be delayed in young patients?
Most cases should be delayed until the patient >2 years old, ideally >10 years
Why should most cases of splenic infarction be delayed until the patient is >2 years of age?
To ensure appropriate immune response can be developed post-splenectomy
What is recommended following extensive splenic infarctions?
Vaccinations against Pneumococcus, N. Mengitidis, and H. Influenza
Life-long antibiotic cover
Why should patients with extensive splenic infarction receive vaccinations and life-long low dose antibiotics?
Due to the spleens role in protection against encapsulated bacteria, which cannot be performed as effectively in those with extensive infarctions
What is the prognosis of splenic infarctions?
The prognosis of splenic infarctions varies enormously
What does the prognosis of splenic infarction depend on?
The cause and severity of the disease
Which patients have an extremely good prognosis following splenic infarction?
Patients with benign underlying disease, and asymptomatic infarcts
Which patients have a poor outcome following splenic infarction?
Patients with splenic infaction secondary to haematological malignancy
What are the most common complications of splenic infarction?
Splenic rupture
Splenic abscess
Pseudocyst formation
What will most complications of splenic infarction warrant?
Splenectomy
When will a splenic abscess be seen post-splenic infarct?
When the underlying cause was from a non-sterile embolus, such as infective endocarditis, or in rarer cases where the patient is immunocompromised
How does a non-sterile embolus cause a splenic abscess?
The embolus seeds infection to the necrotic splenic tissue
What is the problem with the diagnosis of a splenic abscess?
It can be difficult to differentiate from an uncomplicated infection
How can a splenic abscess be diagnosed?
Based on CT scanning viewed by an experienced radiographer, especially when combined with raised inflammatory markers
How will most cases of splenic abscess be confirmed?
Explorative surgery
What is auto-splenectomy?
A rare condition that results in asplenism
What causes auto-splenectomy?
Repeated splenic infarctions, resulting in the progressive fibrosis and atrophy of the spleen. When this continues over a prolonged period of time, it can lead to complete atrophy of the spleen
When is repeated infarction particularly likely to cause auto-splenectomy?
During childhood
What is the most common cause of auto-splenectomy?
Sickle-cell anaemia
How does sickle-cell anaemia cause auto-splenectomy?
Repeated sickle-cell crises lead to recurrent occlusion of the splenic artery.
