A urethral tear is a serious injury involving a rupture or laceration of the urethra, the tube that carries urine from the bladder out of the body. While relatively rare, this trauma requires immediate medical intervention due to its potential for severe complications. Prompt diagnosis and treatment are necessary to restore urinary function and prevent long-term health issues. The injury often occurs in the context of major trauma and can range from minor bruising to a complete separation of the tube.
Anatomy and Types of Urethral Injury
The anatomical structure of the urethra differs significantly between sexes, accounting for the difference in injury risk. The female urethra is short (approximately 1.5 inches) and highly mobile, making it less susceptible to trauma except in cases of severe pelvic fracture or direct injury. The male urethra is much longer (about seven to eight inches) and is fixed in certain areas, which makes it more vulnerable to tearing forces.
The male urethra is divided into two primary segments: the posterior and the anterior urethra. The posterior segment includes the prostatic and membranous parts, which are deep within the body and rigidly held in place by surrounding structures. The anterior urethra, consisting of the bulbar and penile segments, is more exposed to external forces.
Injuries are categorized based on the extent of the damage to the urethral tissue. A urethral contusion is the least severe, representing bruising without an actual tear, and often resolves on its own. A laceration or rupture involves an actual tear, classified as partial or complete. In a partial tear, some continuity of the urethral wall remains. A complete tear involves full separation of the tube, allowing urine to leak freely into the surrounding tissue. This distinction dictates the immediate management approach.
Primary Causes and High-Risk Scenarios
Urethral tears most often result from blunt force trauma, particularly in high-energy accidents involving the pelvis or perineum. The most common cause of posterior urethral injury is a Pelvic Fracture Urethral Injury (PFUI). This occurs when the force of a severe impact causes the pelvic bones to shear and disrupt the deep, fixed portion of the urethra. Such injuries frequently occur in motor vehicle collisions, crush injuries, or falls from a significant height.
Injuries to the anterior urethra are commonly caused by a “straddle injury.” This occurs when a person falls forcefully onto a hard object, such as a bicycle crossbar or a railing, causing a direct blow to the perineum. This force crushes the anterior, or bulbar, urethra against the pubic bone, leading to a tear. These injuries can have delayed consequences, sometimes manifesting years later as a urethral stricture (scar tissue formation).
Beyond blunt trauma, tears can also be caused by penetrating trauma from gunshot or stab wounds, although this is less common. Iatrogenic injuries, caused unintentionally during a medical procedure, are another source of urethral damage. These often result from the difficult insertion of a urinary catheter or during endoscopic procedures, which can cause minor tears or contusions that may later lead to scar tissue.
Identifying Symptoms and Confirming the Diagnosis
A urethral tear is often first suspected based on physical signs and the mechanism of injury. The most important sign suggesting injury is blood visible at the urethral opening (the meatus), which occurs in the majority of cases. Patients may also experience pain in the pelvic or perineal area (the space between the anus and the genitals).
Acute urinary retention is another common symptom, defined as the inability to pass urine despite a full bladder, due to obstruction or surrounding swelling. If urine leaks into the surrounding tissues, swelling and bruising (a hematoma) can develop in the perineum or scrotum. In severe posterior urethral injuries associated with pelvic fracture, the prostate gland may feel displaced or “high-riding” on examination due to detached supporting ligaments.
To confirm the diagnosis and determine the extent of the tear, medical professionals use a specialized imaging procedure called a retrograde urethrogram (RUG). This procedure involves gently injecting a radiopaque contrast dye directly into the urethral opening, followed by X-ray images. It is important that a standard Foley catheter is not inserted before this imaging, as it could convert a partial tear into a complete one, worsening the injury.
The retrograde urethrogram allows the urologist to visualize the entire length of the urethra. If the contrast dye leaks out of the tube into the surrounding tissues, it confirms the presence of a tear. The pattern of leakage indicates whether the injury is partial (some dye still flows into the bladder) or complete (all the dye extravasates at the rupture site, showing clear separation).
Treatment and Long-Term Management
The immediate management of a urethral tear focuses on diverting urine away from the injury site to prevent infection and further damage. This is typically achieved by placing a suprapubic catheter. This small tube is inserted through the skin of the lower abdomen directly into the bladder, allowing drainage while avoiding manipulation of the torn urethra, which is necessary for healing.
Initial surgical repair is generally avoided in the acute setting, especially for severe posterior tears associated with pelvic fractures, because the patient is often unstable from other injuries. Instead, a delayed approach is preferred, allowing the patient to stabilize and local inflammation to subside, which can take three to six months. In some less severe partial tears, a urethral catheter may be carefully placed to stent the urethra and allow it to heal.
The long-term definitive treatment often involves a reconstructive surgery called urethroplasty, performed months after the initial trauma. This procedure involves excising the damaged, scarred section of the urethra and reconnecting the healthy ends in a tension-free manner (an anastomotic repair). For longer or more complex injuries, tissue grafts, such as those taken from the inside of the cheek, may be necessary to reconstruct the damaged segment.
While urethroplasty has a high success rate in restoring urinary function, patients must be aware of potential long-term complications stemming from the initial trauma. Scar tissue formation (urethral stricture) is the most common issue, often requiring follow-up monitoring. Severe posterior injuries can also damage the nerves and muscle structures in the pelvis, which may lead to urinary incontinence or, in approximately 40% of cases, erectile dysfunction.