- Urethra Anatomy
Urethral stricture facts
- Urethral stricture disease is much more common in men than in women. In fact, urethral stricture is rare in women.
- Congenital urethral strictures (present at birth) are rare.
- Any inflammation of the urethra resulting from injury, trauma, previous surgery, or infection can cause urethral stricture.
- Symptoms of urethral stricture can range from no symptoms at all to complete urinary retention.
- Imaging studies and endoscopic evaluations are important tools in the diagnosis of urethral stricture.
- Medications have a limited role, and endoscopic and surgical procedures remain the mainstay of treatment for symptomatic urethral stricture disease.
- The overall prognosis for urethral stricture is good.
What is the urethra?
The urethra is a hollow tube that allows urine to leave the bladder. In men, the urethra starts from the lower opening of the bladder, the bladder neck, and traverses the entire length of the penis. In women, it is a shorter opening coming off the lower opening of bladder and is between 2.5 to 4 centimeters (cm) in length. In both males and females, muscle (urethral sphincter) surrounds the urethra. The urethral sphincter closes the urethra to keep urine in the bladder, and just prior to urination, the sphincter muscle relaxes to allow urine to leave the bladder and pass through the urethra.
The posterior urethra and the anterior urethra are the two principal segments of the urethra in males. The posterior urethra is composed of the prostatic and membranous urethra and extends from the bladder neck to the end of the verumontanum (the region where the ejaculate [sperm and fluids] enters the urethra). The anterior urethra is composed of the bulbar urethra, penile urethra, and the fossa navicularis. The corpus spongiosum completely surrounds the anterior urethra. Subdivisions of these segments include the following:
- The urethral meatus, which is the opening at the tip of the penis
- The fossa navicularis, which is the urethra located proximal to the urethral meatus and within the glans, head of the penis
- The penile urethra, which is the urethra that goes from the urethral meatus to the distal edge of the muscle, the bulbocavernosus muscle
- The bulbar urethra goes from the beginning of the proximal urethra back to the end of the membranous urethra. The bulbocavernosus muscle surrounds the bulbar urethra.
- The membranous urethra is a short area of the urethra that extends from the proximal bulbar urethra to the distal verumontanum (the verumontanum is a small mound in the urethra where the ejaculatory ducts open into and sperm enters the urethra).
- The prostatic urethra is the urethra that goes from the end of the bladder neck (outlet of the bladder) to the verumontanum.
- The bladder neck, the outlet of the bladder
What is a urethral stricture?
Urethral stricture refers to chronic fibrosis and/or narrowing of the lumen of the urethra. Depending on the severity of the stricture, the flow of urine (urinary stream) may or may not be affected. Urethral stricture disease is associated with varying degrees of fibrosis of the spongiosum. Urethral stricture is the term applied to abnormal narrowing of the anterior urethra, whereas the American Urologic Association prefers the term stenosis for narrowing of the posterior urethra, which lacks spongiosum.
What are the risk factors and causes of urethral strictures?
Any inflammation of urethra can result in scarring, which then can lead to a stricture or a narrowing of the urethra. Trauma, infection, tumors, iatrogenic urologic interventions such as urethral instrumentation (catheter placement, cystoscopy), transurethral surgeries, treatment of prostate cancer, 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 narrow the urethra, but is not a stricture.
In developed countries, the most common cause of urethral stricture is idiopathic (41%, no cause identified) followed by iatrogenic (35%). Iatrogenic causes include strictures related to hypospadias (a congenital abnormality where the urethral meatus is located on the underside of the penis, anywhere from the perineum to just short of the head of the penis) and strictures from endoscopic procedures (for example, cystoscopy or transurethral prostatectomy). In developing countries, trauma (36%) is the most common cause of 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), straddle injuries
- Pelvic injury (fracture of the pelvic bones) or trauma
- Previous procedures involving the urethra (urinary catheters, surgeries, cystoscopy)
- Previous prostate surgery (TURP or transurethral resection of the prostate for prostate enlargement, radical prostatectomy for prostate cancer)
- Prostate enlargement
- Cancer of the urethra (rare)
- Infections of the urethra (sexually transmitted infections 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
- Brachytherapy (placement of radiation seeds into the prostate) for prostate cancer
- Diaper-related irritation to the urethral meatus (opening at the tip of the penis)
- Inflammatory conditions such as lichen sclerosus (previously referred to as balanitis xerotica obliterans in males), Reiter's syndrome
What are the symptoms and signs of a urethral stricture?
Some of the possible symptoms and complications of urethral stricture include the following:
- Difficulty starting urine flow (hesitancy)
- Painful urination (dysuria)
- Urinary tract infection (UTI)
- Urinary retention
- Incomplete emptying of bladder
- Decreased urinary stream
- Dribbling of urine
- Spraying or double streaming urine
- Blood in the urine (bloody or dark-appearing urine) known as hematuria
- Blood in the semen (hematospermia)
- Urinary incontinence (loss of bladder control)
- Pelvic pain
- Discharge from the urethra
- Reduced ejaculation force
- Stones in bladder
- Straining to urinate
- Safe sex
What type of doctor treats urethral obstruction?
Most commonly, urologists manage urethral strictures. Urologists are doctors with training and specialization in the urinary system.
How do physicians diagnose urethral strictures?
Doctors make a diagnosis based on history, physical examination, and one or more studies to determine the location and extent of the stricture.
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 infections diseases (gonorrhea, chlamydia) are some of the tests that physicians may order. A doctor may examine the prostate and screen for prostate cancer (manual exam and measurement of prostate specific antigen or PSA) depending on the history, symptoms, and age of the male. A uroflow study may be obtained, whereby one urinates into a special collection container that can measure the rate of the flow of urine and the pattern of the urine stream. In addition, an ultrasound like machine, a bladder scanner assesses the amount of urine left in the bladder (postvoid residual).
Oftentimes, imaging and endoscopic studies are necessary to confirm the diagnosis and identify the location, length, and extent of the narrowing from the stricture.
Are there any special tests for diagnosing urethral strictures?
The following are some common imaging and endoscopic tests in evaluating urethral stricture:
- Ultrasound of the urethra
- Retrograde urethrogram
- Cystography, filling and voiding (VCUG)
- Antegrade cystourethrogram
- MRI and CT scan
Ultrasound of the urethra (ultrasound urethrography) is one of the radiologic methods in evaluating urethral stricture. An ultrasound probe can be 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 noninvasive method and usually does not require any special preparation. However, the location of the stricture limit an ultrasound of the urethra. Ultrasound of the urethra is more helpful in identifying strictures in the part of the urethra that passes through the penis. Currently, doctors may use ultrasound of the urethra in addition to other studies, such as retrograde urethrogram (RUG) to define the stricture before surgery.
Retrograde urethrography is another X-ray test to evaluate urethral strictures. This test entails placing a small urinary catheter in the last part of the urethra, the urethral meatus (the opening at the tip of the penis). A health care professional gently inflates the balloon of the catheter to hold the catheter in place during the study. Then a physician injects a small amount (10-20 cc) of an iodine contrast material into the urethra via the catheter and takes radiographic pictures 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, length of the stricture, and presence of other abnormalities.
Cystography, filling and voiding (VCUG) is helpful to look at the first part of the urethra, proximal urethra. In this study, an individual drinks water to fill his/her bladder and then voids under fluoroscopy.
Antegrade cystourethrogram is a similar test that a health care professional performs if there is a suprapubic catheter in place (a urinary catheter placed in the bladder through the skin in the lower abdomen). A health care provider injects iodine contrast 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 instrument that is a thin tube (cystoscope) with a light within it and a camera at the tip is inserted into the urethra to look directly at the inside (lumen) of the urethra. A health care professional cleans the tip of the urethral opening to prevent infection and applies a local lubricant and anesthetic gel for comfort. Then a physician passes an endoscope through the urethra into the bladder to detect any anatomical or structural abnormalities and obtain a biopsy if he or she suspects urethral cancer. Cystoscopy is limited as the length of the stricture and the exact location may not be able to be fully identified due to the size of the scope and the degree of narrowing of the urethra. In individuals with a suprapubic tube in place, a health care provider can perform the cystoscopy with a flexible tube through the suprapubic tract, termed antegrade cystoscopy.
MRI and CT: Physicians use these studies less frequently to evaluate urethral strictures but in certain cases may be helpful, such as in individuals with a history of a fracture of the pelvic bone(s).
What is the treatment for urethral strictures?
Once a stricture has developed, it will not go away. The role of medications in the management of primary urethral strictures is limited.
Surgery is the recommended treatment for individuals with symptomatic urethral strictures.
A doctor may recommend surgery in the following circumstances:
- Severe problems with urination, such as straining to urinate, weak stream, and urinary retention (inability to urinate)
- Stones in the bladder
- Recurrent urinary 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 strictures?
There are several surgical treatments available for treating urethral strictures, some are more invasive than others. The treatment recommended may vary with the location, length, and severity of the stricture as well as an assessment of the risks and benefits of the procedure.
The common procedures include
- urethral dilation,
- direct vision internal urethrotomy (DVIU),
- urethral stent placement, and
- open urethral reconstruction.
When deciding the most appropriate form of treatment, it's important to take into account the stricture etiology, location, and severity, prior treatments, comorbidities, and patient preference. Physicians typically place a urethral catheter after urethral stricture treatment as it may serve as a stent around which the site of urethral intervention can heal.
Urethral dilation is a commonly attempted technique for treating urethral strictures. The goal of urethral dilation is to stretch the scar tissue without injuring the lining of the urethra. A physician performs the procedure in the office under local anesthesia or in the operating room under general anesthesia. A health care professional gently inserts thin rods of increasing diameters into the urethra from the tip of the penis (meatus) in order stretch the narrowing without causing any further injury to the urethra. A health care provider typically places a catheter after the dilation and removes it approximately 72 hours after the procedure, if it was uncomplicated. It may be necessary to repeat this procedure from time to time, as strictures may recur. However, the AUA guidelines recommend urethroplasty instead of repeated endoscopic management for recurrent anterior urethral strictures following failed urethral dilation of direct vision internal urethrotomy. The shorter the stricture, the less likely it is to recur after a dilation procedure. Occasionally, physicians give patients instructions and dilation instruments (rods, lubricating gel, and anesthetic gel) to perform the urethral dilation at home as needed, particularly those patients who are not candidates for urethroplasty. A risk of urethral dilation is the risk of making the stricture worse over the long term.
Direct vision internal urethrotomy (DVIU) is an endoscopic procedure performed under general anesthesia. A physician inserts a thin tube with a camera (endoscope) into the urethra to visualize the stricture (as describe in earlier section). Then a physician passes a tiny knife through the endoscope to cut the stricture lengthwise to open up the stricture and widen the urethra. A physician then inserts a Foley catheter (urinary catheter), which is kept in place for a few days to a week while the urethral incision is healing. For individuals with a soft stricture that is short, <1 cm long, located in a segment of the urethra called the bulbar urethra, DVIU has a stricture-free rate of 50%-70%. The success of DVIU in other locations and more dense strictures is often less. Complications after DVIU include bleeding, pain, urinary tract infection (UTI), troubles with erections, and recurrent stricture. Use of the laser to open up the scar tissue does not appear to be any better than using the knife. DVIU may be repeated if the stricture recurs, however, as with urethral dilation, urethroplasty should be offered for recurrent anterior urethral strictures after failed DVIU.
Bladder neck contracture (vesicourethral stenosis) may occur after surgical management of prostate disease, including transurethral prostatectomy for benign prostatic hypertrophy (BPH) and radical prostatectomy for prostate cancer. Dilation or incision initially treats bladder neck contracture. Recurrent bladder neck contracture may require surgical reconstruction.
Urethral stent placement is another endoscopic procedure aimed at treating urethral strictures. Depending on the location of the stricture in the urethra, a health care provider may pass a closed tube (stent) through an endoscope to the area of the stricture. Once it reaches the proper location, a physician will open the stent to form a patent tube or conduit for urine to flow. This may be helpful in individuals who are too sick to undergo surgery that is more extensive. Information on long-term success rates of urethral stents is lacking. Complications of urethral stent placement include pain, dribbling after urinating, change in position of the stent (stent migration), stent malposition, and blockage of the stent.
Open surgery, urethroplasty, is the gold standard. It has better long-term success rates than other therapies. Doctors may recommend different types of urethroplasty depending on the location and extent of the stricture. There are two types of urethroplasty techniques: tissue transfer procedures and non-tissue transfer procedures. Performance of tissue transfer procedures may require one stage or multiple stages (multi-stage) depending on the availability of tissue, extent, and location of the stricture.
Excision and primary anastomosis urethroplasty is a non-tissue transfer procedure: This procedure involves open surgical removal of the scar and reconnection of the urethra. This procedure works well for short strictures (< 2 cm) located in a special area of the urethra, the bulbar urethra. A catheter left in place after the procedure allows the area to heal. The duration of the catheter will vary with surgeon preference. The success rate of this procedure is up to 90%. Risks of this procedure include risks of infection, bleeding, pain, recurrent stricture, and fistula (a communication between the urethra and the skin), and dribbling after urination.
Augmented urethroplasty involves tissue transfer. For example, if the stricture is long and/or located in the penis, the stricture may be opened and a flap or graft of tissue is sewn on top of the opened urethra to increase the caliber of the urethra (single stage) or less commonly replaced with a tube, made from surrounding tissues, such as nearby skin or from tissue removed from other areas in the body such as from the inside of the cheek (buccal mucosa) (multi-stage). In a multi-stage procedure, the scarred urethra is typically removed and a piece of tissue (graft of flap) is sewn into the area. Several months later the tissue is then made into a tube. To allow the tissue to heal and minimize urine leakage during healing, a catheter is left in place. The duration of the catheter may vary with the extent and location of the stricture and whether the procedure is being performed in a single stage or in two stages. Individuals with lichen sclerosis related stricture disease should not use penile or genital skin for the urethroplasty due to possible involvement of this tissue with the lichen sclerosis. Erectile dysfunction may occur transiently after urethroplasty with resolution in nearly all affected individuals by six months postoperative. Ejaculatory dysfunction (pooling of semen, decreased ejaculatory force, discomfort with ejaculation, and decreased semen volume) is reported in up to 21% of men follow urethroplasty for bulbar urethral strictures.
Pelvic fractures may results in urethral injury and subsequent stricture. The risk of developing a stricture is related to the initial treatment of the injury. If a suprapubic tube is placed at the time of the pelvic injury, there is a high likelihood that a stricture will form. The stricture is repaired when the patient has healed from the other injuries and is treated with excision of the stricture and reapproximation of the ends of the urethra. In some cases, a catheter is able to be passed through the urethral injury into the bladder (primary realignment) at the time of injury, and the urethra is allowed to heal over the catheter. This realignment of the urethra decreases the risk of urethral stricture formation by about 30% and makes surgery for repair of the stricture, if it occurs, easier. Success rates with repairs of urethral strictures from pelvic fractures is about 90%-98% with excision of the stricture and bringing the ends of the urethra together (reapproximation). Complications of pelvic fractures include bleeding, infection, and erectile dysfunction. Complications of the urethral stricture repair include bleeding, infection, and urinary incontinence.
In select circumstances, a perineal urethrostomy may be preferred as a long-term treatment alternative to urethroplasty. A perineal urethrostomy involves making an incision into the urethra, urethrothrotomy, and opening the urethra and sewing it to the perineum (anterior to the rectum and behind the scrotum). With a perineal urethrostomy, the individual would sit on the toilet to urinate.
The treating urologist would recommend the procedure that would be the best option for each individual. As with any medical procedures, there are some degrees of risks and complications associated with any of these operations.
What is the recovery period after surgery to repair a urethral stricture?
The recovery period after surgery will vary with the procedure performed, duration of catheterization, surgeon preference, and overall health status. A catheter (Foley catheter) is left in the penis after almost all surgeries for treatment of a urethral stricture. How long the catheter remains in place will depend on the procedure performed and surgeon preference. Typically, the catheter is left in place for at least 72 hours. In some cases, a suprapubic tube (tube that goes through the lower abdomen into the bladder) may be left in place to drain the urine in addition to the catheter. With less invasive procedures, the duration may be shorter. The discomfort related to the procedure will also vary with much less discomfort with the less invasive procedures, urethral dilation, and internal urethrotomy. With the more extensive surgery, urethroplasty, a more prolonged course can be expected, varying with the extent of the surgery. Procedures such as dilation and internal urethrotomy are outpatient procedures, whereas more complex repairs may be associated with an overnight stay in the hospital. Follow-up is required after urethroplasty to ensure that the repair is healing well and complications such as a fistula (communication between the urethra and the skin), recurrent stricture, and diverticulum (outpouching of the urethra) are identified and treated if they occur.
How are urethral strictures followed after repair?
There is a risk of recurrence of the urethral stricture, and thus follow-up is essential. The physician will ask questions about the force of urine stream, frequency of urination, feeling of complete or incomplete bladder emptying, direction of the urine stream, and other symptoms of urethral strictures. During such follow-up visits, you may be asked to void into a special collection device, uroflow, to measure the speed of urination and the flow of urination. A small ultrasound probe may be placed on the lower part of the abdomen after urination to measure the amount of urine remaining in the bladder (post-void residual). In some cases, a cystoscopy may be performed to look directly at the area of urethra that was repaired.
Urethral strictures in children may result from diaper irritation (meatal stenosis), trauma, prior surgery or instrumentation, or may be congenital. They will often appear with similar symptoms as those in adults.
Meatal stenosis is a narrowing of the opening at the tip of the penis and is felt to occur from diaper irritation in circumcised boys. It may also occur after hypospadias repair. Symptoms include decreased or deflected urine stream. Performing a meatotomy/meatoplasty, crushing the scarred bridge of tissue and cutting it after, is successful in 98%-100% of boys.
For urethral strictures in the penile urethra to the bulbar urethra, dilation is not recommended. DVIU will be successful in approximately 50% of patients. Excision of the stricture if feasible and primary reattachment of the urethral ends is most effective. When this cannot be accomplished, then a patch graft of buccal mucosa is successful.
Is it possible to prevent a urethral stricture?
In general terms, urethral stricture is not preventable as most common causes are related to injury, trauma, instrumentation, or unpreventable medical conditions. Sexually transmitted infections such as gonorrhea or chlamydia are less common causes of urethral stricture, and they can be potentially prevented by practicing safe sex. Judicious use of catheters and instrumentation may decrease the risk of urethral strictures.
What is the prognosis for urethral stricture?
In general, the outlook on urethral stricture is favorable with success rates up to 90%-98%. A thorough initial evaluation may help identify the most appropriate initial treatment strategy and thus decrease recurrence rates. Repeated dilation and DVIU is discouraged as they result in further urethral injury and longer and more extensive strictures.
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