Spontaneous perirenal urinoma induced by NSAID-associated acute interstitial nephritis

Kidney damage from nonsteroidal anti-inflammatory drugs-Myth or truth? Review of selected literature

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely available drugs with anti-inflammatory and analgesic properties. Their mechanism of action is associated with the enzymes of the arachidonic acid cycle (cyclooxygenases: COX-1 and COX-2). The cyclooxygenase pathway results in the formation of prostanoids (prostaglandins [PGs], prostacyclins, and thromboxanes). It affects various structures of the human body, including the kidneys. Medical literature associates the usage of NSAIDs with acute kidney injury (AKI), tubulointerstitial nephritis (TIN), as well as nephrotic syndrome and chronic kidney disease (CKD). AKI associated with the chronic consumption of NSAIDs is mainly attributed to pharmacological polytherapy and the presence of cardiovascular or hepatic comorbidities. The pathomechanism of AKI and CKD is associated with inhibition of the biosynthesis of prostanoids involved in the maintenance of renal blood flow, especially PGE2 and PGI2. It is suggested that both COX isoforms play opposing roles in renal function, with natriuresis increased by COX-1 inhibition followed by a drop in a blood pressure, whereas COX-2 inhibition increases blood pressure and promotes sodium retention. TIN after NSAID use is potentially associated with glomerular basement membrane damage, reduction in pore size, and podocyte density. Therefore, nephrotic proteinuria and impairment of renal function may occur. The following article analyzes the association of NSAIDs with kidney disease based on available medical literature.

Spontaneous Perinephric Urinoma Secondary to Drug Induced Acute Interstitial Nephritis: A Case Report

Urinoma is defined as the extravasation of urine from any part of the urinary collecting system, which causes lipolysis of the surrounding fat, resulting in an encapsulated collection. The most common cause of urinoma is the direct obstruction of the urinary system. The other etiologies include trauma and postinstrumentation/surgery. Parenchymal cause for spontaneous urinoma is exceedingly rare. We present a case of a 30-year-old gentleman who presented with lower abdominal pain and was treated with a Diclofenac injection. The pain got better temporarily, but he presented again with right loin pain after 3 days. His computed tomography scan images revealed bilateral perinephric urinoma. As there was significant deterioration of renal function, he underwent a renal biopsy. The histopathology was reported as acute interstitial nephritis (AIN). Drug-induced AIN is very rarely presented with acute loin or abdominal pain due to spontaneous perinephric urinoma, as it was seen in our case.

Perinephric urinoma following spontaneous renal rupture in the third trimester of pregnancy: a case report and brief review of the literature

Background

Spontaneous formation of urinoma is a rare condition, especially for pregnant women. We report a patient in the third trimester of pregnancy with a spontaneous renal rupture who then develops a urinoma from urine leaking into the perinephric space.

Case presentation

A 23-year-old primagravida was diagnosed with a spontaneous renal rupture and acute left loin pain accompanied by hematuria when she was 35 weeks pregnant. A sub-capsular perinephric cyst then developed to a size of 319 × 175 × 253 mm, and because of discomfort to the patient, we performed Cesarean section. After a healthy male newborn was delivered, fluid was suctioned from a large perirenal cyst that had an estimated size of 300 × 200 × 300 mm. A percutaneous nephrostomy tube was left in the cyst until CT showed no remaining fluid. In the six-month follow-up, the patient showed no perirenal extravasation according to an ultrasound scan, and the urine analysis and renal function tests were normal.

Conclusion

Close follow-up should be recommended for the patient who has renal rupture after conservative therapy, especially for pregnant woman. CT or MRI should be considered in addition to utilizing ultrasound in the management of pregnant women who present with urinomas. Percutaneous nephrostomy is suggested as an appropriate treatment for large urinomas.