Pyeloduodenal fistula as a result of pyonephrosis: a case re
Fistulae between the kidney and the duodenum are rare. Most of these cases involved the right kidney, given its proximity to the intestinal tract. These cases have occurred usually as a result of chronic renal inflammation. They can occur from pyogenic infections of the kidney, inflammatory bowel disease, tuberculosis, penetrating trauma and neoplasms.

Published in the journal Urology Case Reports, the authors present a case of a 59-year-old female with stage 4 fallopian tube cancer status post total abdominal hysterectomy/bilateral salpingo-oophorectomy, and Carboplatin/Abraxane chemotherapy. She had known right hydroureteronephrosis from retroperitoneal spread of the malignancy. She had been getting nephrostomy tube exchanges regularly for 6 months prior to this admission.

However the nephrostomy tube was removed 5 days prior to this admission as Nephrogram post removal showed adequate emptying of contrast. She presented with right flank pain, fever and leukocytosis. Urine analysis did not show pyuria. CT abdomen pelvis showed a new right hydroureteronephrosis with complete uretero-pelvic junction obstruction, but Lasix scan showed no obstruction. She was started on IV antibiotics but continued to have flank pain.

Thus, repeat imaging was done which revealed pyonephrosis with complete UPJ obstruction, with extension into the 2nd part of the duodenum, resulting in a fistula. There was mass effect of this abscess on the ampulla of Vater, causing dilation of the common bile duct.

A nephrostomy tube was placed for decompression. During the procedure, contrast injected into the right renal pelvis travelled to the duodenum, confirming fistula formation. Urine analysis performed on nephrostomy tube drainage revealed >600 WBC and cultures grew ESBL E Coli.