The incidence of ureteral injuries is generally low, with only a few cases reported in the literature [4, 8, 9]. Uretero-digestive fistulas are uncommon and typically associated with urinary surgery or endourologic procedures [10, 11] or resulting from trauma. During laparoscopic surgery, ureteral injuries often go unnoticed, resulting in insidious symptoms and delayed treatment [12]. They are also related to recurrent infection, chronic inflammation, and, in some cases, malignancies [13,14,15].

Ureteral involvement can lead to a range of comorbidities, including stenosis, fistulas, hydronephrosis, chronic pain, recurrent infections, and loss of renal function [16]. Clinical presentations often emphasize the potential for cross-contamination of colonic and urinary tract contents, which can lead to electrolyte abnormalities, diarrhea, recurrent urinary tract infections, pneumaturia, and, in some cases, fecaluria. Digestive symptoms and flank pain are reported less frequently, ultimately contributing to malnourishment. Metabolic acidosis resulting from electrolyte imbalance can be life-threatening in pediatric patients, requiring an urgent repair of the urinary connection to the digestive tract [17].

Postoperative fistulas result in increased morbidity and a more extended hospital stay. Treatment options for these conditions may include nephrostomy tube placement, ureteral stenting, intestinal resection, and urinary tract reconstruction [18]. While surgery is the most common treatment, the endoscopic approach is an increasingly utilized alternative, predominantly in adult patients and often involving stent placement instead of clipping [19].

The approach to urinary tract reconstruction depends on the location and length of the injury. Minor defects can be effectively addressed through endoscopic procedures, such as temporarily placing a ureteral stent for a few weeks. Additionally, a technique involving endoscopic realignment, combining antegrade and retrograde ureteroscopy, is applicable in cases of wholly transected ureters [20]. However, for injuries resulting in longer strictures, these minimally invasive approaches exhibit limited long-term success rates [21].

In open approaches for tuberculous stricture, urogenital malignancy, and strictures post-pelvic surgery, radiation, or trauma, various attempts have been made to utilize different bowel segments, such as ileal, colonic, or appendiceal segments, for open ureteral reconstructions [22, 23]. These segments are opened anti-mesenterically and reconfigured after rotation, resembling the Yang-Monti procedure [24]. However, severe postoperative complications, including metabolic acidosis secondary to renal failure, stenosis, and fistulas, have been reported after bowel interposition [25].

Full-length ureteral defects can also be reconstructed using only the urinary bladder. One method involves creating a spiral bladder muscle flap while preserving branches of the superior vesical artery. This flap demarcated slightly longer than the ureteral defect, is spirally wrapped around a stent and anastomosed to the proximal end of the ureter. Other successful operative techniques include ureteroureterostomy, ureter cystostomy with psoas hitch, and Boari flap [25,26,27].

Another proven technique involves injecting indocyanine green into the stricture ureter via nephrostomy and ureteral catheter. Visualization of indocyanine green with near-infrared fluorescence allows for the clear identification of the ureter, stricture length, and localization [28]. The most successful outcomes are observed when these techniques are combined and tailored to individual cases, and all the methods are now used in laparoscopic and robot-assisted approaches [11, 29].

Distal injuries are often successfully managed with vesicoureteral reimplantation only or psoas hitch procedure. In cases of long ureteral loss, procedures like Boari vesical flap reconstruction can achieve success rates exceeding 80% [30] (Fig. 5).

This case highlights the patient's improved condition, achieved through the successful closure of the ureterocolonic fistula using an endoscopic clip with a nephrostomy. This approach allowed for the planning of subsequent fistula resection and ureteral reconstruction with a vesical flap. The follow-up confirmed patency from the bladder to the renal pelvis during a retrograde cystogram.