Splenic Infarction: ED Presentation, Evaluation, and Management
- Aug 23rd, 2021
- Marshall Howell IV
Authors: Marshall Howell IV, MD (EM Resident Physician, Emory University SOM/Grady Memorial Hospital) and Eliot Blum, MD, FACEP (Assistant Professor/Attending Physician, Dept of Emergency Medicine, Emory University SOM/Grady Memorial Hospital) // Reviewed by: Alex Koyfman, MD (@EMHighAK) and Brit Long, MD (@long_brit)
A 50-year-old male with a history of rate-controlled atrial fibrillation (non-compliant with warfarin), obesity, coronary artery disease, heroin use disorder, and hypertension presents with left-sided abdominal pain. He reports two days of worsening left flank and abdominal pain, chills, nausea, and two episodes of non-bilious, non-bloody vomiting this morning. He reports no significant changes in his diet or bowel movements. He denies trauma to the area or a history of abdominal surgeries. T 38.4C, HR 110, BP 155/95, RR 18, SpO2 99% on room air. On physical exam, his abdomen is soft and tender to palpation in the left upper-quadrant (LUQ) and left flank without rebound or guarding. Bowel sounds are within normal limits. No obvious masses or organomegaly are palpated, but exam is difficult due to body habitus. Labs show a WBC of 16 and LDH twice the normal limit. INR is 1.5. Bedside ultrasound of the LUQ shows no free fluid or subcapsular splenic hematoma. CT scan shows a wedge-shaped infarct in the upper pole of the spleen.
What are the most likely underlying causes for the infarction? What additional studies will you order? What treatments should you start? What is the patient’s expected disposition?
The spleen is a highly vascular, encapsulated organ that serves as a filter for the body’s blood products, a site of antibody production, and protection against encapsulated bacteria in the bloodstream. The spleen receives 5% of the total cardiac output, primarily via the splenic artery, a branch of the celiac trunk.1 Shortly before entering the hilum of the spleen, the splenic artery divides into four or five segmental arteries that supply separate portions of the spleen.
When blood supply to the spleen is diminished or occluded, tissue ischemia and eventual infarction occur in either a segmental or global distribution, depending on the vessel(s) involved.2 Splenic infarction is a rare phenomenon, accounting for only 0.016% of admissions at a single large academic center over 10 years.1,3 The most common causes of splenic infarction are hematologic or hypercoagulable disorders, embolic phenomenon, and splenomegaly.3 Infarction classically leads to symptoms of left-sided abdominal pain, nausea and vomiting, and fever.3,4
While the causes and classical picture of this rare condition may seem clear, the actual presentation may be vague, often mimicking other intra-abdominal pathologies. This condition is a diagnostic dilemma for the emergency physician, and it is important to be aware of its varied presentations and underlying causes.
Hematologic or hypercoagulable disorders account for 15-59% of all splenic infarctions.1,5–7 These conditions include protein C and S deficiencies, factor V Leiden, lupus anticoagulant, polycythemia vera (JAK2 mutation), heparin-induced thrombocytopenia, oral contraceptive use, and others.2,7,8 Patients under 40 years old are most likely to experience splenic infarction due to these disorders, with lupus anticoagulant and JAK2 mutation each accounting for ~10% of cases.1,2,5,7,9 In hemoglobin SS disease, patients have sickling crises that occlude splenic blood flow in response to dehydration, acidosis, hypoxia, and other stressors. Most of these patients’ spleens are completely infarcted and non-functional by the age of 3 months to 5 years.10 Malignancy and intrabdominal infectious processes can also cause infarction by inflammation-induced hypercoagulable state or local extension affecting the splenic vasculature. Recently, cases have been reported of COVID-19 associated splenic infarction in hospitalized patients despite low-standard heparin VTE prophylaxis.11
Thromboembolic disease accounts for 29-67% of splenic infarctions, particularly in patients over 40 years old.1,5–7,12These conditions include atrial fibrillation, endocarditis, and thrombosis of prosthetic valves.13 The majority of these cases are in patients with atrial fibrillation not on therapeutic anticoagulation.4,14 Septic emboli from endocarditis can cause infarction in addition to splenic abscesses, associated with high fevers and severe localized pain (similar to the case above).15
Conditions causing splenomegaly account for 6-31% of all cases of infarction across all age groups.1,5 Splenomegaly can occur from vascular congestion and occlusion in CML, myelofibrosis, malaria, AIDS, MAC, CMV, spherocytosis, autoimmune hemolytic anemia, infectious mononucleosis, and others.2,16,17 In fact, CML and myelofibrosis patients develop splenic infarction at a rate of 50-72%.6,18
Trauma is also a potential cause for infarction, regardless of age. Damage to vasculature and surrounding structures can cause lacerations or compressive hematomas that may limit splenic blood supply.16 There is also an association between splenic infarction and pancreatic disease. A 2015 study found that of their 123 non-traumatic splenic infarction patients, 13% had pancreatic cancer and 6% had severe acute pancreatitis as their primary risk factor.19
Many cases of infarction are initially diagnosed via CT scan without physician identified risk factors. However, it is important that EM physicians consider this broad differential and avoid labelling the infarct as cryptogenic. Approximately 38% of splenic infarctions are the first evidence of a previously unrecognized illness.2,5,7 Presence of splenic infarction should trigger an investigation for an underlying cause.
The classic (historical) patient presentation for splenic infarction was left-sided abdominal pain, tenderness to palpation over the spleen, and splenomegaly.5,20 Today, with increased CT scan usage and infarct detection, splenic infarction can present in a multitude of ways, from asymptomatic to intense pain with infectious symptoms.
In five case series from 2008-2020, the most common symptoms of splenic infarction included left-sided or LUQ abdominal pain (20-65%), non-left-sided abdominal pain (14-47%), and fever (19-36%).1,4,5,7,21 Between 9% and 33% of patients have no abdominal pain.1,4,5,7,21 Other reported symptoms included splenomegaly, epigastric pain, chest pain, referred shoulder pain, nausea, vomiting, and dyspnea.2,7
These varying symptoms may have significant overlap with other splenic pathologies such as splenic artery aneurysm or splenic abscess, as well as non-splenic pathologies including pancreatitis, peptic ulcer disease, left lower lobe pneumonia, and many other conditions. In other cases, the clinical presentation provides no indications, and the diagnosis is made upon imaging, laparoscopy, or laparotomy.18
Due to the varied presentations mentioned above, physical exam can be misleading in the diagnosis of splenic infarction. Assessment of spleen size is a difficult physical exam maneuver. A 2015 study showed a 40% sensitivity for the detection of splenomegaly with physical exam, whereas ultrasound-aided exam had a sensitivity of 100%.16,22 Physical exam may be used by the emergency physician as an adjunct in diagnosis but should never rule out splenic infarction.
Unfortunately, there is no disease-specific laboratory workup for the diagnosis of splenic infarction. Recommended labs include CBC, CMP, coagulation studies, lipase, and LDH. In case series from 2008-2020, the most common lab abnormalities were leukocytosis (56-67%) and elevated LDH (69-72%).4,5,7 While a relatively non-specific marker of inflammation, one study also showed CRP to be elevated in 39 of 40 splenic infarction patients.7
Imaging is central in diagnosing splenic infarction in the emergency department. The recommended modality for diagnosis in the ED is CT abdomen with IV contrast, ideally performed during the conventional portal venous phase.2,4,7,23,24 CT can assess the number of infarcts, determine the extent of thrombosis, identify possible sources, and evaluate for complications such as abscess or rupture.16 The classic infarct will appear as a pyramidal wedge with the apex pointing toward the hilum.23 CT angiography could also be used for infarct detection, but this modality is conventionally reserved for IR treatment, rather than diagnosis of splenic insults.24
Ultrasound may be used to investigate splenic infarction and other causes of LUQ pain. When mature (days), infarction will appear as hypoechoic areas in the splenic parenchyma with absent doppler flow.23,25 However, compared to CT, B-mode ultrasound has only a 50% sensitivity in detecting the acute phase of infarction (hours to days) due to minimal change in echogenecity.26 Detection of infarction by bedside ultrasound is also restricted by differences in operator skill and interpretation of images.4,5 If arterial and venous phase contrast-enhanced ultrasound is performed by radiology, the infarcted region will remain hypoechoic throughout all phases, and sensitivity increases to nearly 100%.23,26
While not the most sensitive option for ED diagnosis, bedside ultrasound is fast and, in an unstable patient, can help quickly distinguish between infarction and other splenic insults. Look for evidence of intraperitoneal free fluid from splenic rupture, hypoechoic fluid within the capsule indicating a hematoma, or poorly demarcated hypoechoic areas with internal echoes and septations concerning for abscess. If infarcts are visualized on ultrasound, CT with IV contrast is warranted to investigate the extent and possible complications of the infarction. In one series of autopsies, 62% of patients with splenic infarcts were found to have concomitant infarcts in other organ systems.12
Evaluation of Underlying Cause
After infarction is diagnosed on imaging, the highest yield workup to determine the etiology of the infarction includes an EKG, echocardiogram (echo), and blood cultures.7 These tests evaluate for possible atrial fibrillation or arrhythmia, valvular disease or intracardiac thrombi, and bacteremia secondary to endocarditis.7 While obtaining an EKG and blood cultures may be done quickly in the ED, the timing of the formal echo depends upon the patient’s presentation. More severe, symptomatic cases that require monitoring may need the echo in the inpatient or observational setting, while stable patients may obtain theirs on an outpatient basis. Consider a hypercoagulable panel in younger patients with otherwise unknown cause.
Approximately 5% of patients with infective endocarditis will develop a splenic abscess.27 This most often occurs when septic emboli from cardiac vegetations become lodged in splenic vessels, often at the site of previous splenic infarction.17,28 The range of symptoms is similar to splenic infarction, including: LUQ pain, fever, nausea and vomiting, and splenomegaly.17 Recurrent bacteremia of unknown source is another common presentation.17 As discussed above, these abscesses may be visualized by CT with contrast and ultrasound. These patients will require admission for broad spectrum antibiotics with vancomycin and piperacillin/tazobactam or cefepime.17 Most patients undergo abscess drainage or resection.27 Those with large territory abscesses may require splenectomy.17,27
Splenic infarction may rarely lead to spontaneous splenic rupture in patients with a non-traumatic acute abdomen.29This typically occurs due to vascular occlusion and subsequent congestion leading to splenomegaly and rupture. Symptoms include severe abdominal pain with rebound or guarding and signs of shock.29 Diagnosis is made by CT in hemodynamically stable patients and ultrasound in those that are unstable.30 Ultrasound may also show subcapsular bleeding, a sign of future potential rupture. Such atraumatic splenic ruptures require splenectomy in 84% of cases and have a mortality around 12%.17,30
Splenic infarction causes vascular occlusion and increased intravascular pressures, which can produce splenic artery aneurysms. These aneurysms are particularly important due to their risk of rupture and retroperitoneal hemorrhage, especially when >2cm in size.17,31,32 Symptoms often include abdominal pain, nausea, and vomiting.17 The gold standard for diagnosis is CT angiogram of the abdomen and pelvis.32 Vascular surgery or IR interventions include resection, stenting, endovascular coiling, or embolization, many of which can ultimately lead to worsening infarction.17,31
Patients that are hemodynamically stable with well-controlled pain should be considered for medicine admission or observation with appropriate consultation with hematology, cardiology, oncology, or rheumatology, based upon imaging results and the most likely cause. Patients should be given PO or IV fluids, analgesics, and anti-emetics for symptomatic care.16 If appropriate based upon etiology, patients should be started on anti-coagulation (discussed below). Symptoms of mild infarction typically abate within 7-14 days.2
Unstable patients with evidence of hemorrhage require resuscitation, admission, and consultation with surgery or interventional radiology.16 The majority of splenic infarction cases, both traumatic and atraumatic, are treated non-operatively, but those with hemodynamic instability may be candidates for splenectomy or endovascular interventions. Patients with fever and evidence of endocarditis or abscess will also require admission for broad spectrum antibiotics and potential abscess drainage.17,27
Patients with splenic infarction may require anticoagulation, depending upon their underlying etiology. When starting anticoagulation in patients with splenic infarction secondary to arterial or venous thrombosis, most sources recommend enoxaparin (LMWH) bridge to warfarin with an INR goal of 2.0-3.0.8,33,34 Patients with reversible causes of thrombotic infarction, such as OCP use, have been shown to benefit from beginning LMWH and bridging to warfarin (INR goal 2.0-3.0) for a total of 3 months.8 Patients with hypercoagulable disorders, atrial fibrillation, or cryptogenic infarcts should receive LMWH as a bridge to warfarin for indefinite anti-coagulation in addition to hematology or cardiology consultation.3,17,34,35 Patients with vaso-occlusive but non-thrombotic conditions, most notably sickle cell disease, will not benefit from anti-coagulation.17
In patients with large territory infarction, it is important to provide necessary vaccinations to protect against encapsulated organisms, including pneumococcus, meningococcus, and Haemophilus influenza type B.16
- The classical presentation of splenic infarction is a patient with left-sided abdominal pain, nausea, vomiting, and fever, but actual presentations are often ambiguous and mimic other pathologies.
- In patients under 40, the most common cause of infarction is a hematologic or hypercoagulable disorder. In those over 40, most infarctions are the result of thromboembolic disease.
- The gold standard for diagnosis is abdominal CT with contrast. Ultrasound may be useful in the unstable patient to distinguish infarction from splenic rupture or subcapsular hemorrhage.
- ~38% of splenic infarctions are the first presentation of an underlying disorder. Begin the investigation in the ED with an EKG, blood cultures, and echo (if possible).
- Stable patients with controlled pain may be admitted or observed with symptomatic care and appropriate consults based upon the most likely etiology. Unstable patients or those with signs of abscess or hemorrhage require admission with surgical and possible IR consultation.
- Ami S, Meital A, Ella K, Abraham K. Acute Splenic Infarction at an Academic General Hospital Over 10 Years. Medicine (Baltimore). 2015;94(36). doi:10.1097/MD.0000000000001363
- Chapman J, Helm TA, Kahwaji CI. Splenic Infarcts. In: StatPearls. StatPearls Publishing; 2020. Accessed November 4, 2020. http://www.ncbi.nlm.nih.gov/books/NBK430902/
- O’Donnell M, Shatzel JJ, Olson SR, et al. Arterial thrombosis in unusual sites: A practical review. Eur J Haematol. 2018;101(6):728-736. doi:https://doi.org/10.1111/ejh.13165
- Antopolsky M, Hiller N, Salameh S, Goldshtein B, Stalnikowicz R. Splenic infarction: 10 years of experience. Am J Emerg Med. 2009;27(3):262-265. doi:10.1016/j.ajem.2008.02.014
- Lawrence YR, Pokroy R, Berlowitz D, Aharoni D, Hain D, Breuer GS. Splenic infarction: an update on William Osler’s observations. Isr Med Assoc J IMAJ. 2010;12(6):362-365.
- Nores M, Phillips EH, Morgenstern L, Hiatt JR. The clinical spectrum of splenic infarction. Am Surg. 1998;64(2):182-188.
- Wand O, Tayer-Shifman OE, Khoury S, Hershko AY. A practical approach to infarction of the spleen as a rare manifestation of multiple common diseases. Ann Med. 2018;50(6):494-500. doi:10.1080/07853890.2018.1492148
- Abdallah A-O, Kaur V, Mahmoud F, Motwani P. Image Diagnosis: Splenic Infarction Associated with Oral Contraceptive Pills in a Healthy Young Woman. The Permanente Journal – Kaiser Permanente. Accessed February 1, 2021. http://www.thepermanentejournal.org/issues/2017/6407-splenic-infarction.html
- Jaroch MT, Broughan TA, Hermann RE. The natural history of splenic infarction. Surgery. 1986;100(4):743-750.
- Tintinalli J, Ma O, Yealy D, Meckler G, Stapczynski J, Cline D, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9th Edition. McGraw-Hill Education; 2020.
- Qasim Agha O, Berryman R. Acute Splenic Artery Thrombosis and Infarction Associated with COVID-19 Disease. Case Reports in Critical Care. doi:https://doi.org/10.1155/2020/8880143
- O’Keefe JH, Holmes DR, Schaff HV, Sheedy PF, Edwards WD. Thromboembolic splenic infarction. Mayo Clin Proc. 1986;61(12):967-972. doi:10.1016/s0025-6196(12)62638-x
- Smalls N, Obirieze A, Ehanire I. The impact of coagulopathy on traumatic splenic injuries. Am J Surg. 2015;210(4):724-729. doi:10.1016/j.amjsurg.2015.05.035
- Schattner A, Adi M, Kitroser E, Klepfish A. Acute Splenic Infarction at an Academic General Hospital Over 10 Years: Presentation, Etiology, and Outcome. Medicine (Baltimore). 2015;94(36):e1363. doi:10.1097/MD.0000000000001363
- Wang C-C, Lee C-H, Chan C-Y, Chen H-W. Splenic infarction and abscess complicating infective endocarditis. Am J Emerg Med. 2009;27(8):1021.e3-1021.e5. doi:10.1016/j.ajem.2008.12.028
- Kann K. Splenic Infarction in Mononucleosis: Pearls and Pitfalls. emDOCs.net – Emergency Medicine Education. Published February 23, 2016. Accessed November 4, 2020. http://www.emdocs.net/splenic-infarction-in-mononucleosis-pearls-and-pitfalls/
- Bona R. Evaluation of splenomegaly and other splenic disorders in adults. UpToDate. Published November 9, 2020. Accessed November 4, 2020. https://www.uptodate.com/contents/evaluation-of-splenomegaly-and-other-splenic-disorders-in-adults?search=splenic%20infarct&source=search_result&selectedTitle=1~83&usage_type=default&display_rank=1#H3864297002
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