Radical cystectomy with urinary diversion is part of the treatment paradigm for muscle-invasive bladder cancer.¹ Cystectomy is also increasingly used as part of extirpative surgery for nongenitourinary pelvic malignancies and is a treatment for severe overactive bladder, obstructed bladder outlet or severe urinary incontinence. Even though cystectomy has a high rate of surgical complications,² most patients do well after urinary diversion. A small subset of patients, however, develop ureteroenteric strictures (UES), which can lead to multiple future interventions. In the setting of new UES, malignancy should always be ruled out with either an endoscopic or percutaneous biopsy. If present, further surgery including distal ureterectomy or salvage radiation therapy is an option.

UES occur in less than 10% of patients after urinary diversion.³ Common causes of UES include vascular ischemia, as is often the case after mobilization of the left ureter, infection or stones. Radiation therapy, either pre- or post-diversion, has classically been thought to be an additional risk factor likely due to radiation-induced vascular ischemia. A recent study of 2,888 patients found a UES rate of 4% at a median followup of 32 months.⁴ Higher BMI, ASA^® score, presence of lymph node positivity and 30-day complications were associated with UES formation. Interestingly, this study found that previous abdominal surgery was the strongest risk factor with a UES rate of 9.3% compared to a rate of 1.9% at 10 years for those without previous abdominal surgery.

UES can be asymptomatic and found on surveillance imaging. Alternatively, UES can present with pyelonephritis, flank pain, abdominal pain sometimes associated with a urinoma, or any signs of infection. If suspicion is high, a renal sonogram is often the first diagnostic modality, and if hydronephrosis is present, an upper tract imaging study such a CT urogram is the next step. MRI or noncontrast imaging can be used if kidney function is impaired.

After UES are identified, shared decision making is paramount to determine if the UES need to be treated. Asymptomatic UES can be left untreated as long as the patient is aware that the involved kidney will likely lose function over time. This may not be a reasonable option for patients who have a likelihood of needing further chemotherapy for malignancy because of possible nephrotoxicity of chemotherapy.

Once a decision to treat has been made, the initial management consists of draining the affected renal unit. A percutaneous nephrostomy is often the treatment of choice because a dilated collecting system makes percutaneous access easy. A stent can then be attempted via an antegrade approach. Accessing the upper tract from the urinary diversion is often difficult due to variability of the location of the ureteral anastomosis and mobility of the enteric segment of the diversion. If feasible, however, a stent can be placed retrograde. An ileal conduit urinary diversion allows for the placement of an “upside-down nephroureteral tube,” which is a stent with 1 curled end in the kidney and the other end, usually without a curl, through the conduit and into the urostomy bag. Stents need to be exchanged on a regular schedule. A stent through an ileal conduit into the stoma can be exchanged without anesthesia. Some patients are comfortable with stents and can be managed indefinitely with routine stent exchanges.

Definitive endoscopic management can be attempted, particularly for stricture less than 1 cm in length.³ Endoscopic management includes balloon dilation or endoluminal incision of the stricture either via a laser or electrosurgery. A cutting balloon catheter (“accusize”) should be used with caution, particularly for left-sided UES because of the proximity to the iliac vessels. As in the placement of stents, an antegrade approach via a percutaneous route is preferred, but a retrograde approach via the urinary diversion can be employed by experienced practitioners. A stent is usually left in place for a few weeks after dilation or incision of the UES. Balloon dilation succeeds in less than 40%, while endoluminal incision is successful in approximately 60% of patients.⁵

If endoscopic management fails or patients have UES not amenable to endoscopic treatment, ureteral reconstruction can be performed. It is important to know the details of the original urinary diversion when planning a ureteral reconstruction for UES. Most urinary diversions consist of separate ureteroenteric anastomosis (Bricker), but the common tunnel approach (Wallace) has become more common with newer robotic techniques likely because of decreased operative time and possible decreased UES rates.

Open ureteral reimplantation remains the standard option for definitive repair and is successful in over 80% of patients but involves a laparotomy and is therefore associated with relatively high morbidity. The operation itself is straightforward and involves identification of the involved ureter and its insertion into the urinary diversion. A catheter placed into an orthotopic neobladder, into the ileal conduit or though the afferent limb of a continent cutaneous diversion can aid in identifying the urinary diversion. Once the enteric segment of the diversion has been identified, the dissection can be limited to the area of the involved ureteroenteric anastomosis. This is particularly relevant for continent cutaneous diversions, where the pouch might involve a large portion of the abdomen but the ureteral anastomosis can be mobilized easily. Reimplantation is performed by resecting the strictured segment of the ureter, spatulating the viable edge of ureter, mobilizing the enteric segment and performing a tension-free new ureteroenteric anastomosis. While stents may not be useful in decreasing ureteroenteric complications after a primary urinary diversion,^6,7 most surgeons leave a temporary stent in place after reimplant for UES. Robotic approaches are gaining increased visibility and can theoretically be performed in the same manner as an open operation, with the caveat that the field is a reoperated field and it may be difficult to lyse adhesions to allow use of laparoscopic instruments.

Ureteral strictures after urinary diversion remain a bothersome problem for surgeons and patients alike, but can be managed well with a stepwise and graded approach.