Suspected Urinary Leak in a Renal Transplant Patient With Unusual Collecting System Anatomy

A 36-year-old man with a history of end-stage renal failure secondary to reflux nephropathy who underwent renal transplantation 18 years earlier presented with acute abdominal pain. He underwent a laparotomy and had a Hartmann's procedure for a ruptured sigmoid diverticulum. Postoperatively his renal function deteriorated, with the serum creatinine level increasing from 0.35 to 0.50 mmol/L. A Tc-99m mercaptoacetyltriglycine (MAG3) renal scan was performed and a urinary leak was initially suspected. However, after correlation with ultrasound and prior surgical notes, this was found to be the result of an unusual collecting system anatomy. The patient's creatinine level gradually returned to baseline. The initial increase in creatinine was attributed to acute tubular injury after the surgery.