Urethral Trauma - Etiology, Diagnosis, and Treatment

Introduction

Urethral injuries are rarely seen and are caused by childbirth, severe trauma, and improper catheterization. Urethral trauma can be seen as urethral crush, bruising, laceration, and transection. Urethral trauma is not life-threatening but, if left untreated, can cause serious complications. Most urethral trauma causes are iatrogenic or traumatic etiologies with high-energy mechanisms. Management of urethral injuries is based on the location and anatomical locations, particularly in males. The male urethra is divided into anterior and posterior divisions precisely by the urogenital diaphragm.

What Is the Etiology of Urethral Trauma?

Etiology is classified into anterior and posterior injuries. Posterior injuries have shearing force mechanisms, whereas anterior injuries have a crushing force mechanism. Anterior urethra injuries are caused by:

• Motor vehicle trauma.

• Straddle injuries.

• Blunt traumas.

• Penetrating traumas.

Posterior urethra injuries are caused by:

• Pelvic fractures.

• Iatrogenic etiologies.

Iatrogenic injuries are caused by improper catheterization and transurethral instrumentation. They are the most common causes of urethral trauma. 32 % of all urethral injuries are caused by inappropriate catheterization. Individuals having an enlarged prostate are at a higher risk of urethral injury because of the frequent placement of foley catheters. Urethral trauma also occurs due to improper handling or removal of foley catheters seen in individuals who are disoriented, confused, or agitated. These individuals can cause a potential problem and can minimize the issue through the following steps:

• The catheter is taped against the skin, making it difficult for the individual to grip it tightly.

• The catheter is run through and underneath the thigh so that the individual cannot find the catheter.

• The individual is suggested to use pajamas, pads, mesh pants, and diapers to protect the catheter.

• Decoy catheters are used and taped to the diapers or pads. Decoy catchers are not attached to anything; hence, when the individual tries to pull, it does not cause any harm.

Following these steps help to reduce urethral trauma, which is self-induced by the individual due to inappropriate catheter extraction. Urethral injuries are often seen in association with penile fractures. A surgical approach manages these injuries. Urethral injuries in females are an obstetrical complication. Vaginal deliveries mostly cause urethral injuries. The anterior urethra is commonly injured during straddle injuries caused by motor vehicle trauma, and the posterior urethra is injured during pelvic fractures. Other causes include self-mutilation in psychiatric individuals and penile fractures caused due to vigorous sexual activity.

What Is the Epidemiology of Urethral Trauma?

Ten percent of urethral injuries are caused due to blunt or penetrative trauma. It is common among males in the age group of eleven to twenty-five. Men are ten times more prone to urethral injury than women. This is because of the anatomical difference in the urethras. Females have a shorter and more mobile urethra than males.

What Is the Pathophysiology of Urethral Trauma?

Urethral injuries cause scar tissue formation, leading to stenosis, fibrosis, or stricture formation. Urethral injuries can lead to contusions and transection. Urine retention can cause complications in individuals who have been intubated, causing hydronephrosis, or in extreme cases, may cause kidney failure.

What Is the Presentation of Urethral Trauma?

Individuals present with a recent history of trauma, urological surgery, or pain during sexual intercourse. On physical examination, the individuals have:

• Blood in the urethral meatus.

• Pain during voiding.

• Inability to urinate.

• Pelvic instability.

• Palpable bladder caused due to urine retention.

• Scrotal or labial swelling.

• Bruising on the perineum (butterfly pattern).

• High-riding prostate.

The individual may complain of symptoms such as:

• Swelling.

• Pain in the stomach.

What Is the Diagnosis of Urethral Trauma?

Retrograde urethrography is a joint investigation performed to check for urethral injury. Retrograde urethrography is preferred because of its good utility and user-friendly techniques that assess the individual at the bedside. Retrograde urethrography involves 20ml to 30ml of water-soluble, diluted contrast medium injected into the urethral meatus, followed by an x-ray. A positive report suggests extravasation of the contrast medium outside the urethral tract's winding cylinder. The drawback of retrograde urethrography is that it fails to identify the exact location of the injury and needs technique-sensitive handling. Computed tomography is an imaging test that can check the intra-abdominal urinary system, including the ureters, kidneys, and bladder. In blunt trauma cases, computed tomography is preferred. The drawback of computed tomography is it fails to examine the penile urethra. Ultrasonography is sometimes used as a preliminary screening test for urethral injuries. Ultrasonography detects air within the bulbocavernosus.

How Is Urethral Trauma Classified?

Classification of the urethral injury helps in treatment planning and management.

• Type 1: stretched and intact posterior urethra.

• Type 2: pure posterior urethral injury with a tear in the membranous urethra above the urogenital diaphragm, complete or partial.

• Type 3: combined posterior and anterior urethral injury with urogenital diaphragm involvement, complete or partial.

• Type 4: bladder neck injury which extends to the urethra.

• Type 4a: base of the bladder injuries with periurethral invasion.

• Type 5: pure anterior urethral injury, partial or complete.

What Is the Treatment for Urethral Trauma?

Treatment for urethral injuries is a multifactorial approach. Surgical cases are categorized into three types:

• Immediate : 0 to 10 days.

• Delayed: 10 to 14 days.

• Late: More than three months.

Surgery involves the debridement of open or penetrating injuries, establishment of bladder neck competence, epithelial apposition, and enough blood supply to the anastomosis. In cases of blunt trauma to the anterior urethra, the individual may be suggested to undergo bladder.

Decompression. Immediate management techniques involve endoscopic urethral realignment. This may be followed by antibiotic therapy to prevent secondary infection.

What Is the Differential Diagnosis for Urethral Trauma?

The differential diagnosis involves:

• Pelvic bone fracture (open or closed).

• External genital injury.

• Retroperitoneal hematoma.

• Ureteral injury.

• Urinary bladder injury.

• Renal injury.

• Penile fracture.

• Urethral contusion.

• Incomplete versus complete urethral disruption.

What Are the Complications of Urethral Trauma?

Complications involve:

• Secondary infection.

• Abscess formation.

• Fournier's gangrene.

• Urethral stricture and stenosis.

• Fibrosis.

• Obliteration of urethral lumen.

• Urethrocutaneous fistula formation.

• Urinary incontinence.

• Erectile dysfunction.

Conclusion

Urethral trauma occurs when an external force hurts the urethra. Treatment is mainly surgery, and the prognosis is generally good. Urethral injuries are rarely seen and are caused by childbirth, severe trauma, and improper catheterization.