Renal infarction usually occurs in patients with cardiovascular risk factors, such as arterial hypertension, atrial fibrillation, ischemic heart disease or valvulopathy, previous infarction or thromboembolism [1]. However, this condition can also be associated with malignancies, trauma, clotting disorders, kidney transplantation, fibromuscular dysplasia, Marfan and Ehlers-Danlos syndromes [2] or cocaine use [3].

Symptoms start abruptly and consist of abdominal, flank, costovertebral or lower back pain, nausea, vomiting, fever and sometimes oliguria [4] and hematuria [5]. Blood pressure may be high during the acute episode [6]. Small renal infarction may only cause fatigue [7].

On examination, the affected kidney may be palpable or tender. Symptoms due to shock such as hypotension, tachycardia and prolonged capillary refill time may be present.

If the disease occurs in pregnant women, symptoms include vaginal bleeding, lower abdominal pain and uterus contractions.

• Fever

  Patients with fever, flank pain, and dysuria frequently are encountered in the emergency department. [ncbi.nlm.nih.gov]

• Abdominal Pain

  Acute abdominal pain is one of the most frequent complaints evaluated at emergency departments. Approximately 25 % of abdominal pain patients discharged from emergency departments are diagnosed with undifferentiated abdominal pain. [ncbi.nlm.nih.gov]

• Vomiting

  The most common symptoms were abdominal pain, flank pain, nausea, and vomiting. Leukocytosis ( 10 10(9)/L) and elevated lactate dehydrogenase levels ( 620 IU/L) were the most prominent laboratory findings. [ncbi.nlm.nih.gov]

  Symptoms start abruptly and consist of abdominal, flank, costovertebral or lower back pain, nausea, vomiting, fever and sometimes oliguria and hematuria. Blood pressure may be high during the acute episode. [symptoma.com]

  Snapshot A 68-year-old man presents to the emergency room with a 2-day history of abdominal pain, nausea, and vomiting. He denies any urinary frequency or urgency and denies any recent changes in his diet. [medbullets.com]

• Nausea

  A 62-year-old male patient was admitted with a sudden abdominal pain, right flank pain and nausea. He had a diastolic hypertension at admission and his previous medical history showed atrial fibrillation. [ncbi.nlm.nih.gov]

  Symptoms start abruptly and consist of abdominal, flank, costovertebral or lower back pain, nausea, vomiting, fever and sometimes oliguria and hematuria. Blood pressure may be high during the acute episode. [symptoma.com]

• Right Flank Pain

  Here we present a case of a 41 year-old male who was admitted for acute onset right flank pain with fevers and rigors. A CT abdomen with contrast showed findings concerning for right pyelonephritis or renal infarction. [ncbi.nlm.nih.gov]

• Left Flank Pain

  We present an original case of a 41-year-old man, complaining of acute severe left flank pain, resistant to common analgesic therapy, who was diagnosed of segmental renal infarction of a branch of left renal artery. [ncbi.nlm.nih.gov]

• Hypertension

  Hypertension was diagnosed during the study of hematuria in the first case and due to a hypertensive emergency in the second case. [ncbi.nlm.nih.gov]

  Hypertension 2016; 68:832–839. Copyright 2018 Wolters Kluwer Health, Inc. All rights reserved. [journals.lww.com]

• Diastolic Hypertension

  He had a diastolic hypertension at admission and his previous medical history showed atrial fibrillation. Initial clinical diagnosis was aortic dissection. [ncbi.nlm.nih.gov]

• Left Ventricular Dysfunction

  A 57-year-old man had been followed up for severe left ventricular dysfunction after acute myocardial infarction with a left ventricular thrombus. [ncbi.nlm.nih.gov]

• Back Pain

  He had complained of back pain 7 days after the ICD shock. Renal infarction was suspected, although computed tomography and magnetic resonance imaging could not be performed because of chronic renal failure and the presence of his ICD. [ncbi.nlm.nih.gov]

  Symptoms start abruptly and consist of abdominal, flank, costovertebral or lower back pain, nausea, vomiting, fever and sometimes oliguria and hematuria. Blood pressure may be high during the acute episode. [symptoma.com]

  Acute renal infarction as a cause of low-back pain. South Med J. 2003;96(5):497-9. 2. Dursun B, Yagci B, Batmazoglu M, Demiray G. Bilateral renal infarctions complicating fibromuscular dysplasia of renal arteries in a young male. [bjuinternational.com]

  If patient is suffering from acute renal infarction posse’s low back pain, flank and many more problems, in this stage, clinical treatment is not sufficient but it includes many treatments. [renaltreatment.com]

  Two nights prior to admission to our hospital, the patient experienced pain in the left flank, and the day before coming in, he had left lower back pain. [jxym.amegroups.com]

• Low Back Pain

  Acute renal infarction as a cause of low-back pain. South Med J. 2003;96(5):497-9. 2. Dursun B, Yagci B, Batmazoglu M, Demiray G. Bilateral renal infarctions complicating fibromuscular dysplasia of renal arteries in a young male. [bjuinternational.com]

  If patient is suffering from acute renal infarction posse’s low back pain, flank and many more problems, in this stage, clinical treatment is not sufficient but it includes many treatments. [renaltreatment.com]

• Meningism

  Subsequently, he was found to have pneumococcal infective endocarditis, pneumococcal pneumonia and bacterial meningitis, namely Austrian syndrome. He underwent an early aortic valve and mitral valve repair but still had a poor clinical outcome. [ncbi.nlm.nih.gov]

• Akinesia

  Echocardiography showed marked hypokinesia/akinesia in the mid-anterior, mid-anterolateral, and mid-inferior wall of the left ventricle and mild hypokinesia in the apical region. [ncbi.nlm.nih.gov]

• Flank Pain

  Acute renal infarction is a well known, although relatively unfrequent, cause of flank pain resistant to administration of spasmolytic and nonsteroidal anti-inflammatory drugs. [ncbi.nlm.nih.gov]

• Hematuria

  Symptoms start abruptly and consist of abdominal, flank, costovertebral or lower back pain, nausea, vomiting, fever and sometimes oliguria and hematuria. Blood pressure may be high during the acute episode. [symptoma.com]

  Enhanced abdominal computed axial tomography scan showed renal infarction, and urinalysis showed no hematuria. Selective renal angiography was essential to evaluate the extent of dissection and suitability for repair. [ncbi.nlm.nih.gov]

  […] cell carcinoma", keywords "Carcinoma, transitional cell, Hematuria, Infarction etiology, Kidney/blood supply, Urologic neoplasms", author "Castle, {Erik P} and T. [mayoclinic.pure.elsevier.com]

  Indeed, there was almost a significant difference in the patients with hematuria who had normal renal function (10 of 21) compared to the patients without hematuria who had normal renal function (5 of 18, p 0.059), indicating that the absence of hematuria [journals.lww.com]

• Oliguria

  After operation, oliguria and renal dysfunction developed, and he was admitted to our hospital because of acute renal failure after trauma. [ncbi.nlm.nih.gov]

  Symptoms start abruptly and consist of abdominal, flank, costovertebral or lower back pain, nausea, vomiting, fever and sometimes oliguria and hematuria. Blood pressure may be high during the acute episode. [symptoma.com]

  Of the clinical symptoms, pain was present in 81 of 89 (91%) cases, vomiting in 40%, fever in 49%, and oliguria in 16%. [journals.lww.com]

• Anuria

  Hemorrhagic renal infarction due to renal vein thrombosis Signs and Symptoms Flank pain or abdominal pain Hematuria Arterial hypertension Irregular heart rate Nausea, vomiting Oligouria, Anuria Diagnostic Work-Up Urine: Signs for kidney infarction are [urology-textbook.com]

  Renal artery embolism successfully revascularized by surgery after 5 days’ anuria. Is it never too late? Nephrol Dial Transplant 1996; 11:1843–1845. 13. Olin JW, Froehlich J, Gu X, Bacharach JM, Eagle K, Gray BH, et al. [journals.lww.com]

• Bilateral Flank Pain

  We report the case of a previously healthy 43-year-old white man presenting with acute bilateral flank pain. The pain was more severe on the left side. [ncbi.nlm.nih.gov]

Blood workup in suspected renal infarction patients should include a complete blood cell count that may show leukocytosis [8], elevated levels of lactate dehydrogenase, [9], creatinine, blood urea nitrogen, as well as, C-reactive protein and aminotransferases [2]. Fibrinogen level will be low and fibrin-degradation product levels will be high. Metabolic acidosis, hyperkalemia, and hypocalcemia may be encountered. Other causes of lactate dehydrogenase elevation, such as myocardial infarction, hemolysis or malignancy should be excluded. Urinary analysis will show macroscopic or microscopic hematuria [6] and proteinuria [2].

An electrocardiogram is useful in order to determine if atrial fibrillation, a risk factor for renal infarction, is present. Other imaging studies include spiral computer tomography, renal ultrasound, computer tomography or classical angiography and dimercaptosuccinic acid or diethylenetriamine penta-acetic acid radioisotope scan. Computer tomography is used to exclude nephrolithiasis [5] and other lesions. It shows a typical wedge-shaped parenchymal opacification defect, while angiograms are capable of highlighting the occluded vessel [10]. Seldom, the renal vein may also be occluded. If contrast agents are used, the physician should consider their toxicity on an already compromised kidney and even order hemodialysis, if needed.

The infarction usually involves both the cortical and medullary areas and extends into the renal capsule. Hematoma, if present, indicates kidney trauma or transection. If contrast enhanced computer tomography is performed eight to seventy-two hours after the infarction developed, the cortical rim sign appears: a thin rim of cortex is visualized, due to collateral perfusion. Ultrasound and contrast-enhanced ultrasound, although less precise, may show the absence of flow on color Doppler evaluation [11]. These methods are also capable of detecting preexisting infarctions, that appear as hyperechoic scar tissue. Scintigraphic imaging will show diminished or absent renal perfusion and function.

As a last resort, a kidney biopsy may be performed in order to establish the diagnosis and exclude malignancy, if the patient has no contraindications.

• Glomerular Filtration Rate Decreased

  The estimated glomerular filtration rate decreased to 70 % and recovered to 80 % of the original value after 1 year. The mortality rates were 9 and 15 % at 1 month and 1 year, respectively. [ncbi.nlm.nih.gov]

• Candida

  Although renal involvement can be a sequela of disseminated candidiasis, acute renal infarction secondary to Candida invading the renal vasculature has not previously been reported. [ncbi.nlm.nih.gov]

1. Argiris A. Splenic and renal infarctions complicating atrial fibrillation. Mt Sinai J Med. 1997;64:342-349.
2. Domanovits H, Paulis M, Nikfardjam M, et al. Acute renal infarction: Clinical characteristics of 17 patients. Medicine. 1999;78:386-394.
3. Kramer R, Turner R. Renal infarction associated with cocaine use and latent protein C deficiency. South Med J. 1993; 86:1436-1438.
4. Paris B, Bobrie G, Rossignol P,et al. Blood pressure and renal outcomes in patients with kidney infarction and hypertension. J Hypertens. 2006;24(8):1649–1654.
5. Chu P, Wei Y, Huang J, et al. Clinical characteristics of patients with segmental renal infarction. Nephrology. 2006;11(4):336–340.
6. Krishnan P, Anandh U, Fernandes DK, et al. Renal failure in a patient with primary antiphospholipid syndrome. J Assoc Physicians India. 2002;50:964–966.
7. Iga K, Izumi C, Nakano A, et al. Problems in the initial diagnosis of renal infarction. Intern Med. 1997; 36: 330-332.
8. Korzetz Z, Plotkin E, Bernheim J,et al. The clinical spectrum of acute renal infarction. Isr Med Assoc J. 2002;4(10):781–784.
9. Hazanov N, Somin M, Attali M, et al. Acute renal embolism. Forty four cases of renal infarction in patients with atrial fibrillation. Medicine. 2004;83(5):292–299.
10. Kawashima A, Sandler C, Ernst R etal. CT evaluation of renovascular disease. Radiographics. 2000;20(5): 1321-1340.
11. Malhi H, Grant EG, Duddalwar V. Contrast-Enhanced Ultrasound of the Liver and Kidney. Radiol. Clin. North Am. 2014;52(6):1177-1190.