To the editor:

We present a 69 yearold woman who had a renal transplant and with 11- year- history of type 2 diabetes mellitus and visceral involvement (retinopathy and nephropathy). She also had high blood pressure and chronic renal insufficiency secondary to diabetic nephropathy. The early course after renal transplantation was without complications. The graft achieved good renal function 7 days after the procedure and serum creatinine was 1.4 mg/mL.

In the follow-up the patient referred non-specific abdominal pain, mainly hypogastric two months after the transplantation. A computerized tomography (CT) scan was performed that revealed air collection in the inner wall of the bladder,1 with no alterations in of the graft (fig. 1). The patient referred no other symptoms, except urinary tract infection that was treated with ertapenem for two weeks. Twenty days later a new CT scan was performed that showed a normal bladder with no evidence of air collection. The patient had an indwelling urinary catheter for two weeks, which was removed once the radiological image was normal.

DISCUSSION

Emphysematous cystitis is a rare complication of urinary tract infection, characterized by the spontaneous appearance of gas within the bladder wall or in the bladder. Fifty percent of the patients have diabetes and 62.2% are women. Other risk factors are neurogenic bladder and recurrent urinary tract infections.3 The mechanism for the gas formation is unknown, but several hypothesis have been postulated, one of them being glucose fermentation in the urine. Symptoms present only in 53.3% of the cases. The most frequent ones are abdominal pain (65%) and hematuria (82%). Other less frequent complaints are fever, chills, nausea and vomiting. In patients with renal transplantation emphysematous cystitis is not very usual although there is a great percentage of patients with diabetes who undergo this procedure. E. Coli and Klebsiella pneumoniae, both capable of producing gas, are the commonest etiological agents. The prognosis is usually good with antibiotics and glycemic control,2 except in those patients who present systemic organic dysfunction. Treatment duration depends on the clinical response, but antibiotics are necessary during a mean of 10 days.4

A high index of suspicion should be maintained, especially in patients with diabetes that present urinary tract infection, in order to treat the infection as soon as possible to avoid systemic involvement, for example bacteriemia, that develops in 54% of the patients. A plane abdomen X-ray film and/or an abdominal CT scan5 are enough to rule out this condition.