Ureteral Stricture Treatment & Management

No accepted medical treatment of ureteral strictures currently exists.

Balloon dilation

The most common initial management of benign ureteral strictures is balloon dilation, followed by stent placement for 4-6 weeks. Hafez and Wolf reviewed 8 published series of ureteral strictures managed with balloon dilation.^[8] Success rates ranged from 48%-88%. Of the 280 ureteral strictures treated, the overall mean success rate was 55%. They found balloon dilation best suited for very short nonischemic strictures.

Goldfischer and Gerber summarized the results of balloon dilation in a large series and found this procedure to yield a success rate of 50%-76%.^[9] Factors associated with a good outcome included short duration (< 3 mo) and short length of stricture. Given the frequent need for multiple procedures and the higher success rate associated with endoureterotomy, most urologists recommend endoscopic incision as the initial minimally invasive management of ureteral stricture disease.^[10]

Endoureterotomy

This procedure is also commonly performed for benign strictures and boasts a higher success rate than balloon dilation. Hafez and Wolf reviewed 8 published series of endoureterotomy for benign stricture disease and found success rates of 55-85%.^[8] The overall success rate was 78% in the 156 patients. Goldfischer and Gerber found that an endoureterotomy has a success rate of 62-100%.^[9] In a large review assessing endoureterotomy and factors associated with success, Wolf et al found a success rate of 82% for benign strictures.^[4] Poor renal function (< 25% overall function), long strictures (>1 cm), and tight stricture lumen (< 1 mm) are associated with a poorer outcome. Wolf et al found that the use of triamcinolone injection into the stricture bed and large stents (>12F) are useful for long strictures (>1 cm).^[4] Recent long-term studies indicate a success rate of closer to 50% after 5-year follow-up.

Ureteral metal stents

Metal stents, which have been used to treat end-stage malignant disease, provide proximal decompression, although recurrence of the obstruction is possible. Stent removal is extremely difficult, and stent migration has been reported. Some attempts to apply them to benign ureteral strictures and UPJ obstruction and ureterovesical obstruction have been made. Liatsikos et al reported on their experience of 102 patients with a total of 142 ureters stented.^[11] The primary stent patency rate was 66%. They did not report on the time interval in which the stents became occluded.

Liatsikos and colleagues also reported on their experience using self-expandable metal stents for ureteroileal anastomotic strictures.^[12] They treated a total of 24 ureteroileal conduits with a technical success of 100% and an immediate postoperative clinical success rate of 70.8%. The 1- and 4-year primary patency rates were 37.8% and 22.7%, respectively. Despite the high occlusion rates, the authors contend that the placement of metal stents is appropriate in patients who may not be candidates for open surgery.

Innovations in the materials and design of ureteric stents will likely continue. A number of metallic microcoiled stents coated with polymers that retard stone growth are currently on the market. These stents can be used in patients who require long-term stent changes or in those with malignant obstruction due to terminal illness. The stents can be changed every 6-12 months. Periodic cystoscopy to rule out stent encrustations has been recommended.

Open surgical management

Open surgical management includes various treatment options such as psoas hitch, Boari flap, ureteroneocystostomy, transureteroureterostomy (TUU), intestine interposition, renal mobilization, and autotransplant. All open procedures carry an increased risk of morbidity, increased recovery time, and increased hospitalization time compared with endoscopic approaches.

The surgical approach used depends primarily on the location of the ureteral stricture. Distal strictures that require open repair are best managed with ureteroneocystostomy or a psoas hitch, depending on the proximity to the ureteral orifice. If more length is required, a Boari flap can bridge a 10- to 15-cm defect and may reach the mid ureter.

For midureteral strictures, a primary ureteroureterostomy may be appropriate for short benign strictures with minimal tension. TUU may be used if the donor ureter is of adequate length and the recipient ureter is not diseased. Relative contraindications to TUU (see Transureteroureterostomy) include conditions that may affect both ureters (eg, TCC, urolithiasis, radiation, chronic infection, retroperitoneal fibrosis).

Proximal ureteral strictures may be managed with ureteropyelostomy if length allows. Also, ureterocalicostomy is useful if the renal pelvis is scarred or intrarenal in location.

Long, complex upper tract ureteral strictures have traditionally been managed with nephrectomy, bowel interposition, and autotransplantation. For long, extensive ureteral strictures that are not amenable to repair with urothelium, ileal ureteral substitution may be a satisfactory solution. Franke and Smith have stated that contraindications to ileal ureter substitution include renal insufficiency (serum creatinine level >2 mg/dL), bladder outlet obstruction, inflammatory bowel disease, and radiation enteritis.

Laparoscopic and robot-assisted laparoscopic repair

Laparoscopic and robot-assisted laparoscopic surgery are increasingly used to replicate the results offered by open ureteral stricture surgery. Simmons and colleagues (2007) retrospectively compared 12 patients who underwent laparoscopic surgery with 34 patients who underwent open ureteroureterostomy, ureteroneocystostomy, and Boari flap procedures.^{[13, 14]} The average operative blood loss was 258 mL in the open group versus 86 mL in the laparoscopic group; the hospital stay was a median of 5 days in the open group versus 3 days in the laparoscopic group. The overall complication rate was higher in the open group (15%) than in the laparoscopic group (8%). No significant differences were found in the patency or duration of follow-up between the two groups.

Fugita and colleagues reported 3 successful cases of distal ureteral stricture treated with laparoscopic Boari flap creation.^[15] Modi et al reported the successful use of laparoscopic ureteroneocystostomy with psoas hitch in 6 patients with ureterovaginal fistula in whom endoscopic management initially failed.^[16] The first reported use of laparoscopic ureteroureterostomy was published in 1998 and detailed 9 patients with symptomatic endometriosis of the ureter treated with resection and primary repair.^[17] One patient had recurrent stricture that responded to endoscopic dilation.

With the increasing availability of the da Vinci robot system, this technology has been successfully applied to ureteral stricture disease. It offers the advantage of easier intracorporal suturing and knot tying. Multiple centers have reported small case series documenting successful treatment of distal ureteral stricture with robot-assisted laparoscopic reimplantation, with and without psoas hitch or Boari flap.^{[18, 19]}

Assessing the anatomic details of the stricture is paramount and is often best accomplished with retrograde pyelography and CT scanning with delayed contrasted views. The degree of preoperative obstruction and the relative renal function of the ipsilateral and contralateral kidneys are important. This assessment is usually performed using nuclear renal scanning.

The location of the surrounding vascular anatomy may be important, depending on the stricture site. The location can be delineated preoperatively with using images from spiral CT scanning, magnetic resonance angiography, or intraluminal ultrasonography, if necessary.

Consider collecting a biopsy sample from the stricture in patients with a prior malignancy (eg, ureterointestinal anastomotic stricture after radical cystectomy).

To decrease the risk of perioperative infection, the patient should have a sterile urine culture prior to surgical or endoscopic treatment.

Perform a preoperative mechanical and antibiotic bowel preparation in patients in whom an ileal ureter substitution is a possibility.

Endoureterotomy

An antegrade or retrograde endoureterotomy may be performed, but note that a retrograde endoureterotomy has the advantage of avoiding percutaneous renal access.

Then, ureteral incisions can be performed with an endoscopic cold knife, a small (3F) electrocautery probe, or holmium:YAG laser. The Acusize cutting balloon, with its electrocautery wire over the dilating balloon surface, may also be used under fluoroscopic, rather than endoscopic, guidance. Keep in mind that this is a blind cut when only fluoroscopy is used. This can result in vascular complications, even in patients with normal anatomy.

Incisions should be of full thickness into periureteral fat and for 1-2 cm proximal and distal to the stricture. At times, postincisional dilation may facilitate complete incision. The orientation of the incision should vary depending on the location of the stricture in the ureter. In general, the incision should be directed posterolateral in the proximal ureter, from the UPJ to the iliac vessels, directly anterior over the iliacs, and anteromedial below the vessels. Endoluminal ultrasound may assist with the identification of the periureteral vessels.

Postoperative stenting with a 7F-14F stent for 4-6 weeks is commonly performed.

Ureteroneocystostomy

Ureteroneocystostomy and a psoas hitch can be performed through a Pfannenstiel or lower midline incision, although the lower midline approach is more versatile and can be extended if needed. Both a Boari flap and TUU can be performed through midline incisions. Proximal ureteral surgery can be performed through dorsal lumbotomy or flank incisions, but, if TUU or ileal substitution is considered, the midline approach is most versatile.

All ureteral anastomosis should be widely spatulated and free of tension. Ureteral adventitia should be carefully preserved to avoid injuring the ureteral blood supply. Absorbable sutures are recommended to avoid a nidus for calculus formation. Most ureteral anastomoses in adults are stented with indwelling stents to promote drainage and to minimize urine extravasation. The duration of stenting is controversial; 10-21 days is most common for anastomotic repairs. Drains are sometimes placed postoperatively. Use of a Foley catheter can preclude drainage in many cases.

Ureteroneocystostomy and a psoas hitch should be performed with attention to avoid obstruction. The usefulness of tunneled anastomoses in adults is probably small because the risk of obstruction is likely greater than the risk of reflux. Pantuck and colleagues compared end-to-side direct and nonrefluxing anastomosis following urinary diversion after cystectomy.^[20] They found a significant increase in ureteral stricture in the nonrefluxing group, while the development of hydronephrosis, pyelonephritis, and stone formation did not significantly differ.

Transureteroureterostomy

When performing a TUU, care must be taken to avoid kinking as the ureter crosses the sigmoid mesentery. If possible, this tunnel should be superior to the inferior mesenteric artery.

Ileal substitution should be performed in an isoperistaltic fashion to avoid urinary stasis and to promote drainage.

Antibiotics are used perioperatively and may be continued for 24 hours or until drains are removed.

Drains are left in place until output is minimal (< 30 mL/d) or the drainage is confirmed to be serum, which is accomplished by checking the drain creatinine level. In patients who received an endoureterotomy, stents are left in place for 4-6 weeks. In patients who received anastomotic repairs, stents are left in place for 10-21 days.

If a nephrostomy tube was placed in the patient, it is typically removed last because it can be used to perform antegrade nephrostography to confirm patency.

Early follow-up imaging studies are typically performed 2-4 weeks after stent removal and include renal ultrasonography, IVP, or renal scintigraphy. A serum creatinine evaluation and urine culture are often performed.

If the patient is asymptomatic, imaging is performed at 3 months and then at 6-month intervals for the first 2 years. Most stricture recurrences are identified within the first year after surgery.

For excellent patient education resources, visit eMedicine's Kidneys and Urinary System Center and Imaging Center. Also, see eMedicine's patient education articles Intravenous Pyelogram, Magnetic Resonance Imaging (MRI), and CT Scan.

• Balloon dilation

  • Infection
  • Failure to successfully dilate
  • Loss of renal access
  • Subsequent need for percutaneous nephrostomy drainage
• Endoureterotomy

  • Infection
  • Failure to successfully dilate
  • Loss of renal access
  • Subsequent need for percutaneous nephrostomy drainage
  • Direct injury to adjacent structures (eg, bowel or vascular structures, urinoma formation)
  • Vascular injury: Yamada et al reported that 1 of 20 patients treated with a cold-knife ureterotomy had a major vascular injury that required an immediate laparotomy.^[21]
• Open surgical repair

  • Prolonged ileus
  • Urinoma
  • Prolonged urine leak from repair
  • Bowel injury
  • Sepsis
  • Late adhesion formation
  • Small bowel obstruction
  • Risks of major surgery (eg, deep venous thrombosis, myocardial infarction, surgical mortality)
  • Impaired bladder function: Patients who undergo psoas hitch or Boari flap may develop impaired bladder function.

The success rate of balloon dilation is 48%-88%, with a mean of approximately 55%. The length and location of the stricture are important factors, with short and distal strictures responding best.

The success rate of endoureterotomy used to manage benign strictures is 78%. Higher success rates are achieved in nonischemic strictures, those shorter than 1 cm, and those treated less than 24 months from the etiologic event. In addition, the use of a large stent (>12F) is associated with a better outcome, as is stenting for less than 4 weeks.

The success rate of endoureterotomy used to manage ureteroenteric strictures is 32% at 3 years. Right ureteroenteric strictures tend to have better outcomes compared with left ureteroenteric strictures. Large stents (>12F) are associated with better outcomes, as is longer stenting, ie, over weeks.^[4]

The success rate of balloon dilation used to manage ureteral strictures after renal transplantation is 45%-79%. Antegrade or retrograde cold-knife incision has a success rate of 82% at 26 months.

The success rate of open surgical repair of ureteral strictures is over 90%.

A current controversy involves the usefulness of intralesional injection of steroids to inhibit stricture recurrence. In a retrospective review of 77 endoureterotomies, Wolf et al found that the injection of intralesional triamcinolone was associated with greater success in strictures longer than 1 cm.^[4] The significance of this observation in an uncontrolled review is uncertain.

The future of ureteral stricture management may involve extraurinary tissue used as grafts or vascular pedicle flaps to replace damaged portions of ureter. Naude reported the successful use of buccal mucosal grafts with omental wrap in 4 patients with segmental ureteric loss.^[22] An artificial ureter crafted from silicone-polyester was used in two renal transplant patients with ureteral stricture in whom endoscopic and open repair had failed.^[23] At 12 and 15 months of follow-up, the renal function was stable, with no evidence of obstruction.

Innovative tissue engineering technology may produce ureteral tissue that closely mimics native ureteral tissue for ureteral replacement. Some groups have used xenogenic acellular collagen membranes such as porcine small intestine submucosa for ureteral reconstruction. Atala is using similar technology to engineer bladder, cavernosal, urethral, and ureteral tissue.^[24]