EP606 - Ureterocolic Fistula in a Patient with an Obstructed Encrusted Double J Stent

Purpose/Background: Ureterocolic fistulas are rare pathologic connections between the ureter and colon typically arising from trauma, inflammation, radiation, malignancy, and surgical complications. Although double-J (DJ) stents are vital for maintaining ureteral patency, they may become encrusted over time particularly when these are not replaced regularly - leading to obstruction, infection, and rarely, fistula formation.

Methods/Interventions: A 50-year-old female with high grade serous ovarian carcinoma underwent laparoscopic total hysterectomy with bilateral salpingooophorectomy, omentectomy, and peritoneal stripping overseas in 2018, followed by chemotherapy. A left DJ stent was left in place for an obstructing ureteral stricture following an iatrogenic injury.

Upon returning to the country, systemic treatment was resumed for paraaortic nodal recurrence. Due to poor follow-up, DJ stent replacement was delayed beyond the recommended 6-month interval. Prolonged stent indwelling time caused progressive encrustation and recurrent infections.

Presenting with left flank pain and urinary frequency 15 months after the last stent change, she was admitted for removal of the encrusted DJ stent and cystolithiasis. Intraoperative retrograde pyelography (RGP) revealed a fistulous tract (Fig. 1) between the descending colon and proximal ureter. Proximal transverse loop colostomy and DJ stent replacement were performed as means for fecal diversion and preferential drainage of urine through the stent, in an attempt to facilitate healing of the fistulous tract.

Results/Outcomes: The patient had an uneventful postoperative course, and cancer surveillance showed no evidence of disease. Follow-up distal colonogram (Fig. 2) and colonoscopy confirmed complete resolution of the fistula. Definitive plans include colostomy reversal and repair of the ureteral stricture as resolution of fistula has been established.

Conclusion/Discussion: This patient underwent multiple procedures for obstructive uropathy from a distal ureteral stricture and encrusted stent. The ureteral obstruction, accompanied by infection, led to elevated intraluminal pressure and chronic inflammation, triggering the formation of a fistulous tract to the adjacent descending colon. Repair of the fistula was deferred because of the pre-existing distal ureteral stricture and infection. This case highlights the importance of timely DJ stent replacement and vigilant follow-up in preventing complications, such as fistula formation.

Ureterocolic fistulas typically present with urologic symptoms, as higher colonic pressure causes unidirectional flow into the urinary tract, predisposing patients to infection with enteric flora. Diagnosis may be challenging due to non-specific symptoms and a high index of suspicion is warranted in patients with history of urinary procedures, recurrent infection, pelvic surgery, irradiation, or malignancy. Diagnosis may be confirmed through CT urography, but RGP is the preferred modality in precisely defining the anatomic location and extent of the fistula.

Management requires a multidisciplinary approach. Conservative measures may be attempted but surgery remains the cornerstone of treatment. This includes urinary and fecal diversion, addressing the underlying condition, and optimizing nutrition. For persistent fistulas, definitive surgery involves excision of the tract with segmental resection or primary repair of the affected colon and ureter.

Figure 1
Retrograde pyelogram showing contrast extravasation (yellow arrow) between the proximal ureter and adjacent segment of descending colon
Figure 2
Distal colonogram showing interval resolution of the fistula