Pyeloduodenal fistula as a result of pyonephrosis.

Introduction

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.,

Case

We 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 showed pyonephrosis with complete UPJ obstruction, with extension into the 2nd part of the duodenum, resulting in a fistula (see Fig. 1). 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 traveled to the duodenum, confirming fistula formation (See Fig. 2). Urine analysis performed on nephrostomy tube drainage showed >600 WBC and cultures grew ESBL E Coli.

Fig. 1

Pyonephrosis extending from the right renal pelvis to the 2nd part of the duodenum.

Fig. 2

Contrast injected into the right renal pelvis traveled to the duodenum during nephrostomy tube placement, confirming a fistulous connection.

Discussion

Compared to the initial UA with <2 WBCs, the UA of the nephrostomy drainage was dramatically different, suggesting a complete obstruction. Repeat CT after nephrostomy tube placement showed marked improvement in the size of the pyonephrosis. She was discharged with 3 weeks of IV Ertapenem.