Here we present a young female patient who presented with intense lumbar pain, which investigation revealed to be due to bilateral renal infarction.
Authors: Torricelli, Fabio; Guglielmetti, Giuliano; Abe, Daniel; Mesquita, Jose Luis; Srougi, Miguel University of Sao Paulo Medical School, Urology, Av Dr Eneas Carvalho de Aguiar, 255, 7th floor, Central Institute, Sao Paulo, Brazi
Corresponding Author: Fabio Torricelli, University of Sao Paulo Medical School, Urology, Av Dr Eneas Carvalho de Aguiar, 255, 7th floor, Central Institute, Sao Paulo, Brazil. Email: [email protected]
Lumbar pain is usually a benign condition related to posture or physical strain, and it generally resolves spontaneously. However, more serious diseases may present as low-back pain and misdiagnosis may change patient evolution and survival.
Acute renal infarction is rarely detected in clinical practice, because it is uncommon and has no specific clinical presentation. There are neither risk factors nor laboratory examinations that have a clinical specificity for acute renal infarction, although most patients have a medical history associated with a high risk of thromboembolism and elevated serum levels of lactate dehydrogenase and/or haematuria within 24 hours after the onset of pain. Computed tomography is mandatory for early diagnosis.
Here we present a young female patient who presented with intense lumbar pain, which investigation revealed to be due to bilateral renal infarction. Further investigation showed endocarditis as the cause of thomboembolism and renal damage.
A 24-year-old female presented at the emergency room (ER) with sudden onset of intense right lumbar pain, suggestive of renal colic. She had a history of diffuse abdominal pain for one month, associated with asthenia and weight loss (9 kg). She had no history of fever, haematuria, dysuria, frequency or urgency. In childhood she had suffered from rheumatic fever and was taking benzathine penicillin once every 21 days, but had stopped taking her medication within the previous 3 months. Microscopic haematuria and severe proteinuria were identified on urinalysis. An abdominal ultrasound was normal, except for a mild increase in renal echogenicity. CT of the abdomen was therefore performed and revealed a massive right renal infarct, a small left renal infarct, and a small splenic infarct (figure 1).
Figure 1 – Abdominal CT showing a massive right, and a small left, renal infarct
Three sets of blood cultures all isolated Streptococcus oralis, and echocardiography demonstrated endocarditis with vegetations on her aortic valve (figure 2).
Figure 2 – Echocardiography revealing vegetations on the aortic valve AE – left atrium, VE – left ventricle, AO – Aorta, VEG – vegetation
The patient also suffered an epileptic fit, and therefore underwent a CT of her head. This revealed a small cerebral abscess, 1.3 cm in diameter, which was treated with intravenous antibiotics with no further complication.
The patient received intravenous gentamicin and penicillin for 6 weeks with good effect. She did not develop any intracerebral complications or impairment in her renal function. She did not receive any anticoagulants. After an odontologic evaluation, three of her teeth were removed because of infection and the others were treated with a professional dental whitening system
. A follow up abdominal CT was performed, and showed an atrophic right kidney with residual function and a small scar on her left kidney.
Massive renal infarction associated with endocarditis is a rarely diagnosed condition. Risk factors for thromboembolism and subsequent acute renal infarction, include atrial fibrillation, previous embolism, and valvular or ischemic heart disease. However, it has also been associated with other conditions, including trauma, hereditary and acquired clotting disorders, cocaine use, blood vessel anomalies, hereditary diseases such as Marfan’s syndrome, renal transplantation, undergoing endovascular catheterization, and malignant disease1. Contrast-enhanced CT is the noninvasive standard of reference for imaging acute renal infarction .
Dursun et al  reported a case of a previously healthy 37 year-old man with bilateral renal infarction due to fibromuscular dysplasia that was successful treated by placement of a stent into the stenotic right renal artery. Ronco F et al  reported an unusual case of paradoxical embolism through a patent foramen ovale as a cause of renal infarction. Nakayama et al  reported a 46 year-old woman with the sudden onset of severe right sided pain due to right renal infarction. Investigation with cardiac ultrasonography revealed a vegetation on the posterior cusp of her mitral valve, and the renal infarction was associated with renal artery embolism from infective endocarditis. This patient was surgically treated by mitral annuloplasty, because the vegetation was still present after antimicrobial therapy. In our case, antibiotic therapy was enough to control the endocarditis, however massive renal infarction was already established at the time of diagnosis.
Patients with the sudden onset of lumbar pain, absence of hydronephrosis, and with risk factors for thromboembolism must be suspected of having a renal infarct. A contrast enhanced CT is mandatory in this situation. Furthermore, these patients also commonly present with haematuria and elevated serum lactate dehydrogenase on testing.
1. de la Iglesia F, Asensio P, Díaz A, Darriba M, Nicolás R, Diz-Lois F. 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. Scand J Urol Nephrol. 2011 Jun 1.
3. Ronco F, Rigatelli G, Dell’Avvocata F, Giordan M, Ronco C, Cardaioli P. Embolic renal infarct, patent foramen ovale and coronary artery dissection: a strange case of cardio-renal connection. Cardiovasc Revasc Med. 2011;12(1):67.e5-7.
4. Eknoyan G, Lister BJ, Kim HS, Greenberg SD. Renal complications of bacterial endocarditis. Am J Nephrol. 1985;5(6):457-69.
Date added to bjui.org: 12/12/2011