Chapter 11

Urethral Stricture Disease

Definition

1. A urethral stricture results from fibrotic tissue that narrows the lumen and renders the normally compliant urethral lumen inelastic. This results in the slowing or absence of urine flow through the area. Strictures occur as a result of inflammation or trauma from iatrogenic or external sources.

a. The term urethral stricture is correctly used to describe lesions of the anterior urethra. In contrast, posterior urethral “strictures” are more accurately referred to as pelvic fracture urethral distraction defects (PFUDD) that occur in the setting of pelvic fracture. Other obstructive processes of the posterior urethra include prostatic stenosis or bladder neck contractures that occur as a result of prostatic radiation or surgery.

2. The anterior urethra begins at the urogenital diaphragm and includes the bulbar urethra, the penile or pendulous urethra, and the fossa navicularis and meatus.

3. The posterior urethra includes the prostatic and membranous urethra (Figure 11-1).

f11-01-9781455753598 — Figure 11-1 Anatomy of anterior and posterior urethra. (Courtesy of Jack W. McAninch, MD).

Etiology

Trauma

1. Anterior urethra

a. Straddle injuries can injure the bulbar urethra when the urethra is crushed against the undersurface of the pubic symphysis.

b. Penetrating injuries can involve the penile urethra.

2. Posterior urethra

a. Urethral distraction defects as a result of pelvic fracture occur within the membranous urethra. This roughly 2-cm-long segment is between two relatively fixed points (the prostatic apex and the proximal corpus spongiosum, which is fixed to the cavernous bodies).

Iatrogenic

1. Injuries result from traumatic catheterization, instrumentation during other urologic surgeries (transurethral resection of the prostate [TURP], ureteroscopy), or self-induced injury from traumatic Foley catheter removal.

Infection

1. Gonococcal urethritis classically causes anterior, mostly penile, urethra strictures, although these are less common in the antibiotic era.

2. Other sexually transmitted diseases such as Chlamydia trachomatis can also result in stricture disease.

Differential Diagnosis

1. Bladder outlet obstruction from:

a. Bladder neck contracture

b. Prostatic obstruction

2. Meatal stenosis

3. Detrusor failure or atonic neurogenic bladder

4. Detrusor-sphincter dyssynergia

Clinical presentation

Obstruction

1. The classic history is that of obstructive urinary symptoms, that is, slowing of urinary stream, decreased caliber of the stream, increase in voiding time, incomplete bladder emptying, and postvoid dribble.

2. Meatal strictures can result in splaying or splitting of the urinary stream.

Secondary complications

1. Infection

a. Obstruction of the flow of urine often leads to “upstream” infections such as prostatitis or epididymoorchitis.

Diagnosis is largely clinical, based on history. Clinical suspicion can be supported by a flow rate and curve determination and/or assessment of postvoid residual. The shape of the flow curve is as important as or more important than the actual rate measurement. A “plateau” pattern, in which the flow rate reaches a rate and continues at this rate and no faster, is indicative of an obstructive process in the urethra.

Urethroscopy

1. This can be used to confirm a clinical suspicion; accurate diagnosis of length and location of stricture should be performed radiographically.

Retrograde urethrogram (RUG) and voiding cystourthrogram (VCUG)

1. Accurate assessment of length and location of stricture is achieved by the correct performance of a RUG and a VCUG.

2. The patient should be placed obliquely at 30 to 45 degrees, with the bottom leg flexed 90 degrees at the knee and the top leg straight. This allows unobstructed lateral imaging of the urethra and limits imaging foreshortening, which occurs with anteroposterior projection.

3. A 12- or 14-F Foley catheter is then placed within the fossa navicularis, and the balloon is inflated with 2 mL of saline to prevent dislodgment.

4. Contrast is then injected by the way of the catheter to opacify the urethra, and images are obtained.

5. In some cases, a voiding study is required to fully evaluate the stricture, especially in proximal lesions. The bladder is filled in a retrograde fashion via this catheter, or a small feeding tube (5 or 8 F) can be navigated through the stricture to allow for bladder filling. This component of the study can show what aspect of the urethral stricture is truly urodynamically significant as proximal dilation and distal diminution of urethral caliber will be seen (Figure 11-2).

f11-02-9781455753598 — Figure 11-2 Positioning for performance of retrograde urethrogram (RUG). (Courtesy of Jack W. McAninch, MD).

Associated conditions

1. Urethral carcinoma can present with a urethrocutaneous fistula secondary to urethral obstruction from stricture and must be ruled out with a biopsy in all patients presenting in this fashion.

2. Periurethral abscess proximal to distal obstruction from the urethral stricture

3. A urethral diverticulum can form proximal to the site of obstruction and cause postvoid dribbling or infections.

Treatment

1. The first step in determining the course of treatment needs to involve a discussion of goals of therapy with the patient. Most treatments that involve dilation or incision can certainly treat the acute problems of urinary obstruction but do not have good long-term success rates (30% to 50%). Formal urethroplasty, utilizing a variety of techniques, can provide long-term success rates near 90% at the expense of a longer operation and longer immediate postoperative convalescence.

2. Algorithm for treatment (Table 11-1)

Table 11-1

Algorithm for Diagnosis and Management of Urethral Strictures

3. Urethral dilation can be performed in the office with local anesthesia with lidocaine jelly and is still a mainstay of therapy for stricture disease. A well-performed dilation may be the least traumatic of all of the minimally invasive techniques. Urethral sounds or filiforms and followers can be employed to perform the dilation. Both techniques are not without risks, however. Urethral false passages and trauma can lead to development of longer and more complex strictures. Urethral dilation should be considered a palliative procedure as definitive successes are extremely rare.

4. A combination of flexible endoscopy and filiform placement can be a valuable tool to ensure correct luminal placement of the filiform. The filiform, placed in parallel next to the scope, is seen to transverse the stricture as opposed to a passage based on feel.

5. Soft dilation is a practice of the placement of a urethral catheter that is changed and increased in size over a period of days or weeks. This has not resulted in long-term success but can atraumatically extend the life of a dilation.

6. Direct vision incisional urethrotomy (DVIU)

a. Incisional urethrotomy is performed endoscopically under sedation or general anesthesia and involves visualizing the stricture endoscopically and incising with a cold knife at the 12 o’clock position to open the stricture. A Foley catheter is then placed for 2 to 10 days. The goal of the incision is to allow for reepithelialization of the urethral lumen, which will result in a lumen of normal caliber.

b. A variation of the aggressive DVIU incision at the 12 o’clock position is multiple small, shallow incisions in a stellate pattern—the radial DVIU. Theoretically, this causes less damage and may result in a recurrence that is only minimally longer and more complex than the original stricture, making formal open urethroplasty easier to perform.

c. Urethrotomies with a hot knife or a laser should be avoided, secondary to the addition of thermal injury to the spongiosal tissue making recurrences longer and more severe.

d. Results

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