What is Urethral Injury?
Urethral injuries, which refer to any damage to the urethra, the tube that allows urine to exit the body, are relatively uncommon. They make up less than 1% of all visits to emergency rooms in the United States. These injuries come in different forms such as crushing, bruising, cutting, or splitting of the urethra. While they don’t pose immediate risks to life, if not treated, they can cause significant health issues. Most of these injuries are unintentionally caused by medical treatment (iatrogenic), but they can also occur from intense physical trauma, which can potentially be fatal. Planning a method for treating these injuries largely depends on the severity and exact location of the injury.
Medical professionals use multiple anatomical landmarks to evaluate, classify, and manage urethral injuries, particularly in males. The male urethra is divided into two parts, the anterior and posterior sections, separated by the urogenital diaphragm, a thin sheet of muscle and connective tissue. The front (anterior) section is made up of the penile and bulbar urethra while the rear (posterior) section consists of the membranous and prostatic sections of the urethra. They are called so based on their relative locations in the body.
What Causes Urethral Injury?
Urethral injuries refer to damage to the urethra, the tube that carries urine out of the body from the bladder. They typically fall into two categories: anterior injuries, which often result from crushing forces, and posterior injuries, typically caused by shearing forces. Anterior injuries tend to occur due to car accidents, injuries from straddling an object, or other forms of trauma. Posterior injuries are frequently related to pelvic fractures or iatrogenic impacts, which are unintentional injuries caused by medical procedures.
Unintentional injury from medical procedures like incorrect urethral catheterization (a tube inserted into the urethra to drain the bladder) is the most widespread cause of urethral injuries globally. For men, it has been estimated that incorrect urinary catheterization is responsible for 6% to 32% of all urethral injuries. This risk is higher in individuals with an enlarged prostate because they often need frequent emergency catheter insertions. Simple medical injuries can generally heal themselves and usually have a good recovery.
An additional common cause of urethral injuries, particularly in men, is when patients who are confused or distressed accidentally pull out their own catheters, causing damage. Nurses make precautionary evaluations to determine the likelihood of a patient improperly removing their catheter and take steps to make it harder for patients to find or grip the catheter. Using special clothing and harmless “decoy” catheters for patients to pull can also prevent self-induced urethral injuries. As these precautions are nurse-led, they can be initiated without a doctor’s permission, allowing for immediate implementation.
Penile fractures occasionally involve partial or complete urethral damage. These injuries are best addressed with prompt surgical intervention.
In women, urethral trauma is commonly an obstetrical complication occurring in approximately 10.3 out of every 1000 vaginal deliveries. Like men, anterior injuries in women typically result from vehicle accidents or from straddling accidents, while pelvic fractures are usually tied to posterior injuries. Notable causes of urethral injuries can also include penile fractures during intense sexual activity, foreign object-related injuries, and self-inflicted harm in individuals with mental health issues.
Risk Factors and Frequency for Urethral Injury
Urethral injuries are reported in approximately 10% of patients who have experienced major blunt or piercing trauma, according to some studies. These injuries occur more frequently in young males, typically between the ages of 11 and 25. In fact, men are nearly ten times more likely to experience a urethral injury than women. Women are less likely to get these injuries due to their anatomy – their urethra is shorter and more flexible, and their uterus is also mobile. However, even with these anatomical advantages, up to 6% of women with pelvic fractures may still have a urethral injury.
Signs and Symptoms of Urethral Injury
Urethral injuries are often identifiable through certain symptoms and physical examination findings. These are typically linked to recent trauma, certain medical procedures involving the urinary system, or sudden pain during sexual intercourse. When examining a patient for possible urethral injury, doctors will likely look for specific symptoms.
- Blood at the urethral opening
- Pain during urination or inability to urinate
- Unstable pelvic area
- Feeling a distended bladder because of inability to urinate
- Swelling of the scrotum or labia
- Prostate gland appearing to be situated unusually high
- Bruises in a “butterfly” pattern in the perineal area (the area between the genitals and the anus)
It’s important to be alert to these symptoms, as they could indicate a urethral injury. The American College of Surgeons highlights three key symptoms as part of their advanced trauma life support guidelines: blood at the urethral opening, inability to urinate, and a distended bladder. If these symptoms are present, the person should be evaluated for urethral injury.
Testing for Urethral Injury
The Retrograde Urethrography (RUG) test is considered the best method for checking the urethra. This test is especially useful for patients who have experienced a trauma, and it can easily be done bedside. It involves injecting a diluted, water-soluble dye into the urethra opening and then taking an x-ray. If the dye leaks out of the urethra, it indicates an urethral injury. While this test is excellent for spotting urethral injuries, it’s not as good at pinpointing the exact location of the injury and the results can vary depending on who is performing the test.
There are also other types of scans that can be used to check for urethral injuries. For example, a Computed Tomography (CT) scan is usually the first choice for examining the urinary system, which includes the kidneys, ureters, and bladder, especially in the cases of blunt injuries. However, a CT scan doesn’t replace the need for a RUG, as it isn’t as effective at checking the penile urethra.
Magnetic Resonance Imaging (MRI) is another option that could be ideally suited for this. But due to logistical issues, it is often challenging to perform. However, some suggest it could be particularly useful for children who have suffered a urethral injury and need a detailed imaging test.
Lastly, ultrasound could be used as an initial check for potential urethral injuries. This could be particularly useful if you have suffered pelvic trauma and there’s a suspicion of urethral injury. The ultrasound can detect the presence of air in the bulbocavernosus (a muscle in the male pelvic area). If air is present, a more detailed imaging test, such as a RUG or CT is needed.
Being able to correctly classify and describe urethral injuries is essential to create an effective treatment plan and facilitate communication between healthcare providers. While several systems exist to help with this, the most commonly used is the Unified Anatomical Mechanical Classification of Urethral Injuries. This system classifies injuries into types based on the area of the injury and whether the injury is partial or complete.
Treatment Options for Urethral Injury
If a urinary tube injury is spotted, urgent medical help from specialized urinary system doctors is required. Sometimes, patients might need to be moved to a hospital that has such specialists. Treating these injuries often involves a variety of steps and there isn’t always a clear agreement on the best course of action. While urinary tube injuries are not instantly dangerous, they do need to be checked promptly to prevent future problems.
Surgeries to fix these injuries can be done right away (within the first 10 days), somewhat later (within 10 to 14 days) or a long time after the injury (more than three months). In cases where the injury is due to a harsh direct hit or a deep and open wound, specialists try to perform the surgery immediately. But for injuries resulting from a penis fracture, the surgery is usually postponed.
The main principles of surgical treatment include the cleaning of deep and open injuries, sewing the torn edges of the urinary tube’s lining back together, ensuring the opening of the bladder works properly, and making sure the joined sections receive enough blood supply.
There are certain key steps that are commonly agreed upon by experts. Firstly, if the patient is unable to urinate or if they have received a blunt hit to the urinary tube, it’s important to ease the pressure in the bladder to prevent any urine leak into the pelvic area or the stomach. Secondly, all sharp penetrating and open urinary tube injuries must be quickly investigated surgically and perhaps be cleaned. Lastly, antibiotics are advised to prevent any potential infections.
There are various ways to handle acute urinary tube injuries after pelvic damage. One option is endoscopic realignment (or rearrangement), which is a refined method most commonly done in experienced hospitals. Here, the tube is flushed with a normal saline solution followed by the introduction of a thin, flexible tube with a light and camera (a cystoscope) through the bladder into the urinary tube. At the same time, another tube is inserted from the other end, and efforts are made to pass a guide wire between the two. Once the guide wire is passed, a catheter (tube to drain fluids from the body) can be inserted for urinary tube realignment. This catheter is usually kept in place (and changed every month) until the urinary tube has healed and its regular function has been established. This process can take anywhere between a month to three months.
If this procedure is not successful, a tube might be inserted above the pubic area for urine drainage, and surgery to fix the urinary tube can be scheduled for roughly three months after the injury.
Currently, the standard suggestion when a urinary tube injury occurs is to insert a tube above the pubis bone (suprapubic cystotomy tube) surgically. Doctors could first try to realign the urinary tube endoscopically (using a cystoscope) or non-endoscopically and insert a catheter, but these attempts shouldn’t be stretched out for long to prevent any contamination or urine leakage. If these attempts fail, a tube can be inserted above the pubic area, and there is a high possibility that a delayed surgery on the urinary tube (urethroplasty) will be required.
What else can Urethral Injury be?
When a person endures an injury to the lower core or pelvic area, medical professionals might need to check for several potential conditions:
- Injury to the exterior parts of the genitals
- A fracture in the pelvic bones, which could be either visible (open) or internal (closed)
- A retroperitoneal hematoma – a type of blood clot that forms behind the lower part of the abdomen
- Injury to the kidneys
- Injury to the urinary bladder – the organ that holds urine
- Damage to the ureters – the tubes that carry urine from the kidneys to the bladder
- A fracture in the penis
- Contusion or bruise to the urethra – the tube that allows urine to exit the body
- Disruption of the urethra, which could be either complete or partial
What to expect with Urethral Injury
Urethral injuries, or injuries to the tube that transports urine from the bladder out of the body, are never life-threatening. However, they are often found in combination with other serious injuries which can complicate treatment. The prognosis, or expected outcome, for these injuries is generally good, but there can be long-term complications. For children, the outcome of a urethral injury is harder to foresee because their tissues are less mature and consequently have less blood supply.
It’s recommended to evaluate sexual function and continence (the ability to control urine release) in children only after they reach puberty. Several studies have been conducted in adults to compare different treatment options in terms of the rates of erectile dysfunction, incontinence, and stricture formation (the narrowing of the urethra). While the quality of these studies varies, collectively they imply that the rates of erectile dysfunction (15%-20%) and incontinence (4%-6%) are roughly the same with any treatment.
However, the rates of stricture formation appear to differ significantly. Treatment strategies that involve early urethral realignment (i.e., surgery to restore your urethra’s normal structure) have an overall stricture rate of about 45%-53%. This rate increases to 89%-97% with treatments that involve the placement of a supersaturate tube (a tube placed into the bladder to drain urine) and delayed urethral repair surgery.
Possible Complications When Diagnosed with Urethral Injury
Urethral injuries can definitely cause future health problems for a patient. These complications can be divided into early complications and late complications. Early complications center around secondary infections, like abscesses, and in extreme cases, a serious infection known as Fournier’s gangrene.
On the flip side, late complications might include narrowing in the urethra and stiffening of the urethral passage. Furthermore, this could lead to the complete closure of the urethral canal, formation of abnormal connections between the urethra and the skin, urinary incontinence, and erectile dysfunction. The most common reason for these injuries is other medical procedures, and these often involve partial urethral injuries, which fortunately have the best prognosis.
Managing minor narrowings in the anterior part of the urethra can be done by dilating the urethra. However, in cases where the narrowing extends more than 2 cm, surgical procedures such as urethrotomy or urethroplasty might be needed. Because the urethral wall in the bulbous part of the urethra is thinner, injuries in this region are managed conservatively, if possible, and then by urethroscopy if needed. For extensive narrowings, a surgical procedure called urethroplasty can be performed.
Potential complications:
- Secondary infections
- Abscesses
- Fournier’s gangrene (in extreme cases)
- Narrowing or stiffening of the urethra
- Closure of the urethral canal
- Abnormal connection between the urethra and skin
- Urinary incontinence
- Erectile dysfunction
Preventing Urethral Injury
It’s essential that healthcare workers and patients who need to use a catheter themselves receive proper education about the risks involved with incorrect catheter use, in order to avoid injuries to the tube that carries urine from your bladder (urethra). Education in the wider community about how to prevent injuries from car accidents, including the correct use of seatbelts, can also help reduce damage to the urethra. Lastly, to avoid injury caused by patients removing their own Foley catheters (a specific type of catheter that’s inserted into the bladder), a plan to prevent this behaviour should be put into place, as mentioned above.
