Extraperitoneal urine leak after renal transplantation: the role of radionuclide imaging and the value of accompanying SPECT/CT - a case report

A 71-year-old male who had sudden anuria, scrotal swelling and elevated creatinine level after cadaveric renal transplantation performed Tc-99 m MAG3 renography to evaluate the renal function, followed by an ultrasound which was unremarkable. An extensive urine leak was evident on the planar images. However, an exact location of the urine leak was unknown. Accompanying SPECT/CT images confirmed a urine leak extending from the lower aspect of the transplant kidney to the floor of the pelvic cavity, presacral region and the scrotum via right inguinal canal as well as to the right abdominal wall.Renal scintigraphy is very useful to detect a urine leak after renal transplantation. However, planar imaging is sometimes limited in evaluating the anatomical location and extent of a urine leak accurately. In that case accompanying SPECT/CT images are very helpful and valuable to evaluate the anatomical relationships exactly.The most effective primary treatment of chronic renal failure is renal transplantation [1-3]. Most surgical complications involve either the wound or one of the three anastomoses (renal artery, renal vein, or ureter). A fluid collection is a common complication after kidney transplantation [1,4-6]. Causes of fluid collection include: lymphocele, urine leak, hematoma and seroma. Fluid collections can be asymptomatic, or may be associated with swelling and pain at the site of the allograft, wound drainage, swelling of the ipsilateral lower extremity, and occult blood loss [4,5]. Approximately two thirds of early urologic complications (urine leaks and obstruction) are apparent in the first month after transplantation [6]. It is often difficult to distinguish the signs and symptoms of urinary extravasation from those of rejection or obstructive uropathy. To aid in the early and definitive diagnosis ultrasound scanning, isotope renal scanning, magnetic resonance urography, antegrade or retrograde urography, and/or cystography are performed [7]. An ultrasound