Case Study - February 2010

This is a CT scan from a 71-year-old woman who had undergone urinary diversion more than 20 years earlier, now presenting with signs of left pyelonephritis and a metabolic acidosis
- What does the CT show?
- How may this be related to her urinary diversion?
- How should she be managed?
Reveal Answer
Open answer There is no fixed answer to this question, however your response should be similar to the one below:
- The CT shows large amounts of gas in the left kidney and ureter with gross dilatation of the left-sided collecting system. The right ureter passes anteriorly and is, in fact, anastomosed to the sigmoid colon, as is the ureter on the left. This lady has had a ureterosigmoidostomy
- Reflux of gas & faeces from the sigmoid into the left kidney has caused these appearances. The metabolic acidosis is due to urinary stasis and re-absorption in the colon
- She should be managed initially with parenteral antibiotics and bicarbonate (to correct her acidosis). Renography should determine whether there is any remaining function in the left kidney
Infection and metabolic acidosis are important risks following ureterosigmoidostomy. There is also a risk of developing adenocarcinoma at the anastomosis due to the combined action of urine & faeces which appears to be carcinogenic. Regular sigmoidoscopy is normal practice following this procedure but this lady had been lost to long-term follow-up.