Multiple Gas-Containing Renal Stones: A Case Report

BACKGROUND Emphysematous urinary tract infections are rare and serious conditions that are often multifactorial in etiology and may be associated with the presence of renal stones. Diagnosis can be made by finding gas within the renal collecting system or parenchyma. However, the radiographic finding of gas within a renal stone is rare and little has been published to describe the significance of this finding, its promoting factors, and management. While finding a single gas-containing renal stone is rare, we present a patient with multiple gas-containing stones. CASE REPORT A 63-year-old woman with a history of diabetes and recurrent nephrolithiasis was found to have multiple gas-containing renal stones during a workup of gross hematuria. She was currently being treated for a urinary tract infection. Imaging revealed multiple stones with central encapsulated air and hydronephrosis. She underwent subsequent lithotripsy and stent placement due to this concerning finding, but developed sepsis 2 days following treatment. Cultures from the lithotripsy isolated Proteus mirabilis. It is hypothesized that lithotripsy resulted in endotoxin-mediated sepsis. CONCLUSIONS Proper management of gas-containing renal stones in the setting of urinary tract infections includes broad-spectrum antibiotics (carbapenem plus vancomycin if obstruction is present) followed by drainage via percutaneous nephrostomy and then stone removal. Immediate lithotripsy should be avoided in cases of emphysematous pyelonephritis as it can result in endotoxin-mediates sepsis.