410 CHAPTER 9 Upper tract obstruction

Management of ureteric strictures (other than UPJ obstruction)

Definition

A normal ureter undergoes peristalsis and therefore at any one moment at least one area of the ureter will be physiologically narrowed. A ureteric stricture is a segment of ureter that is narrowed and remains so on several images (i.e., it is a length of ureter that is constantly narrow).

Causes

Most ureteric strictures are benign and iatrogenic. Some follow impaction of a ureteric stone for a prolonged period. Malignant strictures are within the wall of the ureter (e.g., TCC ureter) or due to extrinsic compression from the outside wall of the ureter (e.g., lymphoma, malignant retroperitoneal lymphadenopathy). Retroperitoneal fibrosis (RPF) may be benign (idiopathic, aortic aneurysm, post-irradiation, analgesic abuse) or malignant (retroperitoneal malignancy, post-chemotherapy).

Mechanism of iatrogenic ureteric stricture formation

Normally it is ischemic:

•Usually injury at time of open or endoscopic surgery (e.g., damage to ureteric blood supply or direct damage to ureter at time of colorectal resection, AAA graft, hysterectomy); at ureteroscopy— mucosal trauma (from ureteroscope or electrohydraulic lithotripsy), perforation of ureter (urine extravasation leading to fibrosis)

•Radiotherapy in the vicinity of the ureter

•Stricture of ureteroneocystostomy of renal transplant

Investigations

The stricture may be diagnosed following investigation for symptoms (flank pain, upper tract infection) or may be an incidental finding on an investigation done for some other reason. The stricture may be diagnosed on a renal ultrasound (hydronephrosis), an IVP, or a CTU.

A MAG3 renogram will confirm the presence of obstruction (some minor strictures may cause no renal obstruction) and establish split renal function. Where ureteric TCC is possible, proceed with ureteroscopy and biopsy.

Treatment options

•Nothing (symptomless stricture in an older patient with significant comorbidity or <25% function in an otherwise healthy patient with a normally functioning contralateral kidney)

•Permanent JJ stent or nephrostomy, changed at regular intervals (symptomatic stricture in an older patient with significant comorbidity or <25% function in affected kidney with compromised overall renal function)

•Dilatation (balloon or graduated dilator) (see Figs. 9.2 and 9.3).

MANAGEMENTOFURETERICSTRICTURES(OTHERTHANUPJOBSTRUCTION)ICTURES 411

Figure 9.2 Balloon dilatation of a lower ureteric stricture.

Figure 9.3 The catheter used for balloon dilatation.

412CHAPTER 9 Upper tract obstruction

•Incision + balloon dilatation (endoureterotomy by Acucise balloon; ureteroscopy or nephrostomy and incision e.g., by laser). Leave a 12Fr. stent in for 4 weeks.

•Excision of stricture and repair of ureter (open or laparoscopic approach)

•Nephrectomy

Factors associated with reduced likelihood of a good outcome after endoureterotomy are as follows:

•<25% function in kidney

•Stricture length >1 cm

•Ischemic stricture

•Mid-ureteric stricture (compared with upper and lower)—tenuous blood supply

•JJ stent size <12 Fr

Ureteroenteric strictures (ileal conduits, ureteric implantation into neobladder)

These are due to ischemia and/or periureteral urine leak in the immediate postoperative period, which leads to fibrosis in the tissues around the ureter.

In ileal conduits, the left ureter is affected more than the right ureter because greater mobilization is required to bring it to the right side and it may be compressed under the sigmoid mesocolon, both of which impair blood flow to the distal end of the ureter.

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