What is Urethral Strictures?
A urethral stricture is when the urethra (the tube that carries urine from the bladder out of the body) becomes narrow, leading to problems with urine flow. This condition frequently happens due to injury to the inner lining and surrounding tissues of the urethra. It’s common enough to cause many doctor’s appointments, emergency room visits, and hospital stays. While both men and women can suffer from urethral strictures, it’s rare in women, and there’s less guidance on how to diagnose and treat strictures in females.
In men, this narrowing can happen anywhere along the urethra, but it usually occurs in the bulbar urethra (a section of the male urethra). The male urethra is categorized into two parts- the anterior (from the external opening to a part of the urethra near the bladder) and the posterior (from that segment of the urethra to the bladder base). The urethra is held within a part of the penis called the corpus spongiosum, which is located below two other parts known as the corpora cavernosa. The urethra’s inner lining consists of a type of skin tissue.
When looking at where strictures often occur, 92.2% happen in the anterior part of the urethra, with almost half occurring in the bulbar urethra, followed by the penile urethra. Sometimes, the stricture can involve both the bulbar and penile urethras, and in rare cases, it can affect the entire urethra.
In 2002, a conference held by the World Health Organization advocated for a more detailed way to identify specific sections of the urethra. They proposed dividing the urethra into seven segments: the outflow opening, the fossa navicularis, and the penile, bulbar, membranous, and prostatic parts of the urethra, and the part connecting to the bladder.
What Causes Urethral Strictures?
Urethral strictures, or narrowing of the urethra, can be caused by four main factors: unknown causes, medical procedures, inflammation, and injury. The most common causes, each at 33%, are unknown causes and medical procedures. Other causes include injury (19%) and inflammation (15%), although sometimes up to 26.6% of strictures can be due to infections, as these strictures are typically longer than 4 cm.
The cause of urethral stricture disease can greatly depend on where in the world you are. In Nigeria for instance, infection is the leading cause of urethral strictures at 66.5%, while it only accounts for 15.2% of cases in Brazil.
In Western countries, the main cause of urethral strictures tends to be unknown (41%), followed by medical procedures (35%), which are usually the result of surgeries or procedures on the urethra. In low-income regions, trauma is the most common cause due to higher rates of traffic accidents, less developed infrastructure, and underdeveloped trauma care. Some unknown causes may actually be due to repeated minor injuries in the genital area that lead to the stricture.
Medical procedures that can cause urethral strictures split into five categories. The first, Transurethral resections (41%), involve large instruments repeatedly passing in and out of the urethra, which can cause injury and eventual stricture. The next, prolonged catheterization (36%), creates pressure in the urethra that can lead to tissue death and frictional injury. Cystoscopy and simple Foley catheterization, which both involve inserting a tube into the urethra, account for 12.7% of cases. Unplanned catheter removals by confused patients can also lead to injury and strictures. Fourth, hypospadias repair, often done in children, causes 6.3% of strictures, with those children having a 10% risk of developing urethral strictures later in life. Lastly, surgery for prostate cancer (3.2%) also leads to urethral strictures, specifically near the bladder neck.
Furthermore, over a large group of patients at the Mayo Clinic, about 5% developed a stricture after prostate surgery. Using a robotic surgical approach and preserving the nerves reduced this rate. Radiation therapy, especially brachytherapy, also increases the risk for urethral stricture, and the risk increases with the radiation dose.
Inflammatory strictures can be caused by an inflammation after an infection that narrows and weakens the urethra, most often a recurrent gonococcal urethritis. These are less common in developed countries due to improved public health measures and education but are still common in developing countries. Yet, how other infections, such as chlamydia, tuberculosis, and schistosomiasis, relate to urethral strictures, is not clear. Recurrent urinary tract infections (UTIs), with Escherichia coli being the most common organism, can also cause urethral strictures.
Lichen sclerosis, a disease causing pale, ivory-colored lesions around the genitals, is another relatively common cause of inflammatory urethral strictures. However, the cause and development of this disease are not clear; there might be a genetic predisposition and an autoimmune factor. Such lesions can extend into the urethra, leading to obstructive symptoms.
Inflammatory urethral strictures due to infection typically only affect the anterior urethra and these strictures are usually significantly longer than those caused by other factors and are therefore more likely to require surgical repair.
Post-traumatic anterior urethral strictures often affect the bulbar urethra, usually due to injury compressing the bulbar urethra against the pubic bone. This usually happens from straddle injuries and rarely from a pelvic fracture. Strictures in the penile urethra due to trauma are rare but can occur after a penile fracture. Severe trauma leading to a pelvic fracture almost exclusively causes strictures in the bulbar or membranous urethra. Although only a relatively small fraction of people who sustain a pelvic fracture develop a stricture (3% to 25%), 84% of people with a traumatic posterior stricture have had a pelvic fracture. These strictures are typically short, with most less than 4 cm in length.
Risk Factors and Frequency for Urethral Strictures
Urethral strictures, or narrowings in the urinary tract, are a common issue, especially among older men or individuals from the black community. They become much more frequent after the age of 55. Each year in the US, about 0.9% of the population is diagnosed with this condition.
This problem leads to a significant number of hospital visits and admissions. Specifically, urethral strictures cause 5000 hospital admissions and 1.5 million clinic visits each year. However, in the UK, the rates are considerably lower, with an estimated 40 out of every 100,000 men up to 65 years of age and 100 out of every 100,000 men over 65 years affected.
It’s important to remember, though, that urethral strictures can occur anywhere. Globally, anywhere from 229 to 627 out of every 100,000 men are believed to have the condition.
Signs and Symptoms of Urethral Strictures
A urethral stricture is a condition that occurs when the urethra (urine tube) narrows, causing problems with urination. Consider this condition when a man has issues like painful urination, weak urine flow, not being able to empty the bladder completely, increased leftover urine after urinating, or frequent urinary tract infections (UTIs).
Typically, urethral stricture develops gradually over time. Its symptoms are similar to those of Benign Prostatic Hyperplasia (BPH), a condition where the prostate gland enlarges and blocks urinary flow. Some of the common symptoms include:
- Weak urine flow
- Struggling to start urinating
- Inability to completely empty the bladder
- Double-voiding (needing to urinate twice within a short period)
- Intermittent urine flow
- Leaking urine after urination
- Painful urination
- Frequent UTIs
- Acute urinary retention (sudden inability to urinate)
- Blood in urine
Despite the blocking of urinary flow, around 70% of patients only experience the above symptoms and no others. However, the severity of these symptoms can differ from patient to patient, especially if the stricture is developing slowly or is small. This discrepancy sometimes results in patients having no symptoms. In those cases, the patient may develop a more muscular bladder to compensate for the blockage.
Two key differences between BPH and urethral stricture disease are that blocked ejaculation can occur in urethral stricture, and urethral strictures do not respond well to BPH treatment protocols such as alpha-blocker medications. Another sign of urethral strictures is a consistently weak urinary stream.
In the diagnosis phase, doctors will inquire about potential causes such as any prior surgeries, infections, or trauma. Additionally, a patient’s full medical history and any other health conditions are also important to know.
While a physical examination may not often confirm a urethral stricture, it is still crucial. The clinician will feel the urethra for any hard lumps, check for any changes in skin color like pale patches that might suggest lichen sclerosis (a skin condition that can cause urethral strictures), especially around the urethral opening. Scars from prior surgeries will also be looked for. Examination of the prostate is very important too, to check for conditions such as BPH, prostate cancer, or prostatitis.
Testing for Urethral Strictures
If your doctor suspects you might have a urethral stricture, which is a narrowing of the tube that carries urine out of your body (the urethra), they will use several methods to confirm the diagnosis.
Your medical history, a physical examination, a urine test, measurement of how much urine you have left after going to the toilet, and measurement of the maximum speed of your urine flow may all be part of this process. These tests will help to suggest if a stricture is present. However, it’s important to know that blood tests are not used to diagnose urethral strictures.
The doctor will also use a test called uroflowmetry. This test measures the speed and volume of urine and is a good, non-invasive way to assess the flow rate of urine through your urethra. If this test shows that the maximum flow rate of your urine is less than 12 mL per second, this might suggest that you have a urethral stricture or at least some sort of blockage. The shape of your urine flow can also provide important clues.
The doctor may also measure the amount of urine left in your bladder after you pee, which can provide an additional clue about the presence of a blockage. However, this cannot definitively diagnose a stricture.
In order to confirm the diagnosis, your doctor might use a cystoscopy, a procedure that involves inserting a special tube (there are flexible and rigid versions) into your urethra to examine it. This procedure is fast, can be done in a clinic, and can also help the doctor determine the stricture’s location. It must be noted that in some cases, like when the stricture is tight, this method might not be able to determine its length or the condition of the urethra above the stricture. Another limitation is that it provides limited information about the fibrosis or scarring in the surrounding tissues. The solution is to use a smaller tube which may be able to go beyond the stricture.
Retrograde urethrography is another technique the doctors use. It involves introducing contrast fluid into your urethra to enable the doctor to see the entire length of the urethra including the bladder on their screen. If the stricture is tight, however, this method might not be able to determine its complete length and in such cases, they may ask you to empty your bladder after filling it with contrast, to get additional information.
Doctors often use a combination of these methods to get a detailed picture of the stricture, including its location and length. Despite these techniques being reliable, they do have limitations – mainly because they only provide a two-dimensional image of a three-dimensional structure. Some studies recommend using computed tomography, voiding urethrography, or sonoelastography to provide more detailed images of the stricture and its characteristics.
For the more complex situations or for diagnosing urethral strictures in women, a technique called videourodynamics is used. This provides a combination of how the bladder empties and imaging of the urethra. It’s especially useful to differentiate between actual strictures and dysfunctional urethras.
Ultrasound is another tool that doctors use, mainly to examine your bladder and the upper part of your urinary tract. It may also indicate how much fibrosis, or tissue scarring, is present in your urethra.
In rare cases, a magnetic resonance imaging (MRI) scan might be used. This technique is primarily used when cancer is suspected to be causing the stricture. An MRI can provide excellent images of the location and extent to which the tumor has spread into surrounding tissues.
Treatment Options for Urethral Strictures
If you’re not experiencing any complications, the primary goal of therapy would be to relieve symptoms. The treatment should be chosen based on how severe the symptoms are, where the stricture is located, how severe it is, the length of the stricture, and your preference. You should not be offered treatment if your symptoms aren’t bothersome or harmful.
If you experience urinary symptoms, such as recurring infections or difficulties with passing urine, treatment can relieve these symptoms, reduce complications, and lessen any damage to the lower part of your urinary tract. If your doctor isn’t sure of the diagnosis, or suspects an infection, they might recommend a course of antibiotics. If antibiotics help to relieve your symptoms, you will need to take them until the course is complete.
The peak urine flow rate in a young healthy male should be greater than 15 mL/second. If the flow rate is less than 12 mL/second, this would be considered low. Treatment is not usually needed if there’s no thickening of the bladder wall or issues with bladder emptying. Treatment should be offered only to those patients who have troublesome symptoms or clear signs of damage in the bladder.
If you’re a female with urethral strictures, the standard initial treatment is urethral dilation (widening the urethra), often followed by self-catheterization (you inserting a tube into the urethra) to keep the urethra open. However, this treatment has a high recurrence rate of over 50%. A more preferable treatment is urethroplasty using buccal grafts or vaginal flaps, as this offers a high success rate of 90%. Because this type of surgery is complex, you would be referred to a urologist specializing in such procedures.
Urethral strictures can be treated using endoscopic procedures (procedures using a medical instrument inserted into the urethra) or open surgical procedures. The type of treatment chosen will depend on the exact location and length of the stricture. Please note that with any treatment options, there is a chance of recurrences, especially if the stricture is long or if it was treated previously.
After treatment, you may be recommended to perform intermittent self-catheterizations to help maintain an open urethra. If you are unable to insert the catheter easily, your doctor may suggest you do it more frequently, or use a smaller catheter. Doing self-catheterizations for 4 months or longer has been shown to reduce the recurrence rates. But you should be aware that a urethroplasty is a safe and effective alternative, especially if you need to perform self-catheterization regularly to keep your urethra open.
Urethroplasty is a surgical procedure in which the narrow part of the urethra is widened or removed and replaced by tissue from another part of your body. This procedure is used for longer strictures and has good outcomes with very high success rate of over 85%. A perineal urethrotomy may be considered for patients who had multiple surgeries for strictures, or for those with extensive or complex stricture disease who do not wish to have more surgeries.
Remember, whatever the type of urethral stricture you have, regular check-ups are necessary to monitor for recurrence.
What else can Urethral Strictures be?
Just like how a narrow or blocked urethra typically shows signs of slow and difficult urination, several other diseases can show similar symptoms. Here are some other conditions that doctors consider when diagnosing this problem:
- Bladder stones
- Bladder muscle weakness or lack of muscle tone
- Nerve issues affecting the bladder, like detrusor sphincter dyssynergia
- Effects of certain medications
- Enlargement of the prostate, either non-cancerous or cancerous. (Having a non-cancerous enlarged prostate is the most common reason for a weak urine stream.)
- Prostate infection, which usually pairs with burning sensation when peeing, increased urge to pee, seeing blood in the urine, intense pelvic pain, particularly when sitting, and cloudy urine with a high level of a protein called prostate-specific antigen (PSA)
- Abnormal flaps of tissue in the urethra, known as posterior urethral valves
- Underactive bladder, bladder stones, reduced bladder sensation
- Foreign objects in the urethra (like a stone)
- Condition where urine flows backward from the bladder toward the kidneys, known as vesicoureteral reflux.
What to expect with Urethral Strictures
Urethral strictures, or narrowings in the urethra, work in a cycle that causes tensions and scarring to continuously increase and at the same time, the size of the lumen (the inner open space of the urethra) to keep shrinking.
Left untreated, the stricture or narrowing will worsen over time and eventually cause complications. It’s important to realize that these strictures often reoccur, especially if they are managed without surgery.
Although surgical treatment using a procedure called urethroplasty is the most effective option to manage this condition. It boasts over an 85% success rate overall.
Another good long-term treatment for urethral strictures, specifically those less than 3 cm in the bulbar urethra (a section of the male urethra), involves balloon dilation coated with a substance called paclitaxel, in combination with a procedure called DVIU (direct vision internal urethrotomy), which is a minimally invasive technique used to remove the stricture.
Possible Complications When Diagnosed with Urethral Strictures
If a urethral stricture is not treated quickly, it may lead to various complications such as:
- Severe difficulties in passing urine,
- Backflow of urine from the bladder to both kidneys,
- Appearance of abnormal pouches in the bladder,
- Problems with getting or maintaining an erection,
- Change in the shape or size of the penis,
- Frequent urinary tract infections,
- Trouble with normal urine release,
- Backflow of urine from the bladder to one kidney,
- The creation of an unnatural passage between the urethra and the skin.
Preventing Urethral Strictures
To decrease the occurrence of urethral strictures, which are narrowings in your urethra, it helps to lessen the chances of injuries or conditions that lead to the problem. Here are some of the ways you can do this:
Firstly, try to prevent injuries to your pelvis, perineum (the area between your genitals and anus), and penis.
Secondly, if you’re using a catheter (a tube to help you absorb urine from the bladder), it’s important to get proper advice. It’s recommended to use a good amount of lubricating gel and use the smallest size catheter you are able to for short periods of time.
Thirdly, if you’re handling your own catheter, it’s vital to learn and master the least harmful method of inserting it. This can prevent damage to the urinary tract.
Lastly, practicing safe sex is very important. Gonorrhea, a sexually transmitted infection, was once the most common cause of urethral strictures. Safer sex practices have significantly decreased the number of urethral strictures caused by this infection, particularly in developed countries. This shows just how effective these practices can be.
