What is the urethra?
In men, the urethra is a thin tube like structure that starts from the lower opening of the bladder and traverses the entire length of the penis. The urethra has a sphincter that is normally closed to keep urine inside the bladder. When bladder fills with urine, there are both voluntary and involuntary controls to open the urethral sphincter to allow urine to come out.
What is urethral stricture?
Urethral stricture refers to any narrowing of the urethra for any reason whether or not it actually impacts the flow of urine out of the bladder. Any inflammation of urethra can result in scarring, which then can lead to a stricture or a narrowing of the urethra. Trauma, infection, tumors, surgeries, or any other cause of scarring may lead to urethral narrowing or stricture. Mechanical narrowing of the urethra without scar formation (developmental causes or prostate enlargement) can also cause urethral stricture.
What are the causes of urethral stricture?
The following are common causes of scarring or narrowing of the urethra:
- Trauma from injury or accidents with damage to the urethra or bladder (for example, falling on a frame of a bicycle between the legs, or a car accident).
- Pelvic injury or trauma.
- Previous procedures involving the urethra (urinary catheters, surgeries, cystoscopy)
- Previous prostate surgery (TURP or transurethral resection of the prostate for prostate enlargement)
- Infections of the urethra (sexually transmitted diseases or STDs, urethritis, gonorrhea, chlamydia)
- Prostate infection or inflammation (prostatitis)
- Previous hypospadias surgery (a congenital birth defect in which the opening of the urethra is on the underside of the penis instead of the tip)
- Congenital malformations of the urethra, which rarely can cause urethral stricture in children
About one-half of causes of urethral stricture are from medical procedures and manipulation of the urethra or nearby structures (surgeries, catheter insertion, etc.). In about one-third of cases, no identifiable cause are found.
What are the symptoms of urethral stricture?
Symptoms of urethral stricture can range from no symptoms at all (asymptomatic), to mild discomfort, to complete urinary retention (inability to urinate).
Some of the possible symptoms and complications of urethral stricture include the following:
- Difficulty starting urine flow
- Painful urination (dysuria)
- Urinary tract infection (UTI)
- Urinary retention
- Incomplete emptying of bladder
- Decreased urine stream
- Dribbling of urine
- Spraying or double streaming urine
- Blood in the urine (hematuria)
- Blood in the semen
- Urinary incontinence
- Pelvic pain
- Discharge from the urethra
- Reduced ejaculation force
How is urethral stricture diagnosed?
When the medical history, physical examination, and symptoms are suggestive of urethral stricture, additional diagnostic tests may be helpful in further evaluation. Urinalysis (UA), urine culture, and urethral culture for sexually transmitted diseases (gonorrhea, chlamydia) are some of the typical tests that may be ordered in this setting. Oftentimes, imaging and endoscopic studies are necessary to confirm the diagnosis and identify the cause of urethral strictures.
Are there any special tests for diagnosing urethral stricture?
The following are some common imaging and endoscopic tests in evaluating urethral stricture:
- Ultrasound of the urethra
- Retrograde urethrogram
- Anterograde cystourethrogram
- Cystourethroscopy
Ultrasound of the urethra is one of the radiologic methods in evaluating urethral stricture. An ultrasound probe can placed along the length of the penis (phallus) and determine the size of the stricture, degree of narrowing, and length of the stricture. This is a non-invasive method and usually does not require any special preparation.
Retrograde urethrogram (RGU) is another radiology test to evaluate urethral strictures. This test basically entails placing a small urinary catheter in the last part of the urethra (closest to the tip of the penis). Approximately 10 cc of an iodine contrast material is slowly injected in the urethra via the catheter. Then, radiographic pictures are taken under fluoroscopy to assess any obstruction or impairment to the flow of the contrast material that can suggest urethral stricture. This test provides useful information about the location, extent, and size of any narrowing in the urethra as well as the shape of any possible abnormalities.
Anterograde cystourethrogram is a similar test but can only be done if there is a suprapubic catheter in place (a urinary catheter placed in the bladder through the skin in the lower abdomen). Iodine contrast is then injected into the bladder via the catheter and its flow out of the urethra is radiographed under fluoroscopy.
Cystourethroscopy is an endoscopic evaluation in which a small camera at the tip of a thin tube is inserted into the urethra for direct visualization of the lumen of the urethra. The tip of the urethral opening is cleansed, and local lubricant and anesthetic gels are applied for comfort. Then the endoscope is inserted into the urethra and bladder. Any anatomical or structural abnormalities will be detected, and a biopsy can be obtained at the same time if necessary.
What is the treatment for urethral stricture?
There are essentially no real medical treatments (medications) for urethral strictures other than those offering symptom control (for example, pain medications to control discomfort). Surgery remains the only treatment for individuals with uncontrolled symptoms of urethral narrowing.
Surgery may be recommended in the following circumstances:
- Severe problems with urination and urinary retention
- Kidney stones in the bladder
- Recurrenturinary tract infections
- Increasing post-void residual (amount of urine left in bladder after urination)
- Failure of conservative measures to control symptoms (pain)
What surgical options are available for urethral stricture?
Many surgical procedures are available for treating urethral strictures. Depending on the cause and other medical and social aspects, the most appropriate procedure may be recommended for each individual case. The common procedures include
- Urethral dilation,
- Optical internal urethrostomy,
- Urethral stent placement,
- Open urethral reconstruction.
Urethral dilation is a commonly attempted technique for treating urethral strictures. This procedure is done under local or general anesthesia. Thin rods of increasing diameters are gently inserted into the urethra from the tip of the penis (meatus) in order to open up the urethral narrowing without causing any further injury to the urethra. This procedure may need to be repeated from time to time, as strictures may recur. The shorter the stricture, the less likely it is to recur after a dilation procedure. Occasionally, patients are given instructions and dilation instruments (rods, lubricating gel, and anesthetic gel) to perform the urethral dilation at home as needed.
Optical internal urethrostomy is an endoscopic procedure that is typically done under general anesthesia. A thin tube with a camera (endoscope) is inserted into the urethra to visualize the stricture (as describe in earlier section). Then a tiny knife is passed through the endoscope to cut the stricture lengthwise and open the flow of urine. A Foley catheter (urinary catheter) is then inserted and kept in place for a few days while the urethral incision is healing. The success rate of this procedure is about 25%, and again, shorter strictures generally have a better response to this procedure.
Urethral stent placement is another endoscopic procedure aimed at treating urethral strictures. Depending on the location of the stricture in the urethra, a closed tube (stent) can be passed through an endoscope to the area of the stricture. Once it reaches the proper location, then the stent can be opened to form a patent tube or conduit for urine to flow.
Open reconstruction entails several possible techniques for correction of urethral strictures. These are surgeries that involve opening the urethra surgically under general anesthesia to fix the stricture. In some, the area of scarring is cut out and the remaining urethra is reconnected. In others, after the scar tissue is removed, a graft from inside the cheek (buccal mucosa) or a skin flap may be used to form a reconstructed urethra. These techniques in general have a good response rate, although they are more invasive than other described procedures.
The treating urologist would recommend the procedure that would be the best option for each individual. As with any medical procedures, there is some degree of risks and complications associated with any of these operations.
Can urethral stricture be prevented?
In general terms, urethral stricture is not preventable as most common causes are related to injury, trauma, instrumentation, or unpreventable medical conditions. Sexually transmitted diseases such as gonorrhea or chlamydia are less common causes of urethral stricture, and they can be potentially prevented by practicing safe sex.
What is the prognosis for urethral stricture?
In general, outlook on urethral stricture is favorable. Depending on the underlying cause, some cases may carry a poorer prognosis.