Urethral Trauma 

Updated: Jan 02, 2019
Author: James M Cummings, MD; Chief Editor: Bradley Fields Schwartz, DO, FACS 

Overview

Practice Essentials

Most urethral injuries are associated with well-defined events, including major blunt trauma such as caused by motor vehicle collisions or falls. Penetrating injuries in the area of the urethra may also cause urethral trauma. Straddle injuries may cause both short- and long-term problems. Iatrogenic injury to the urethra from traumatic catheter placement, transurethral procedures, or dilation is not uncommon.

Urethral injuries can be classified into 2 broad categories based on the anatomical site of the trauma. Posterior urethral injuries are located in the membranous and prostatic urethra. These injuries are most commonly related to major blunt trauma such as motor vehicle collisions and major falls, and most of such cases are accompanied by pelvic fractures. Injuries to the anterior urethra are located distal to the membranous urethra. Most anterior urethral injuries are caused by blunt trauma to the perineum (straddle injuries), and many have delayed manifestation, appearing years later as a urethral stricture.

External penetrating trauma to the urethra is rare, but iatrogenic injuries are quite common in both segments of the urethra. Most are related to difficult urethral catheterizations.

The diagnosis of urethral trauma is made by with retrograde urethrography, which must be performed prior to insertion of a urethral catheter to avoid further injury to the urethra. Extravasation of contrast demonstrates the location of the tear. Further management is predicated on the findings of urethrography in combination with the patient's overall condition. See the images below.

Urethrogram demonstrating partial urethral disrupt Urethrogram demonstrating partial urethral disruption.
Urethrogram demonstrating complete urethral disrup Urethrogram demonstrating complete urethral disruption.

Trauma to the male urethra must be efficiently diagnosed and effectively treated to prevent serious long-term sequelae. Patients with urethral stricture disease secondary to poorly managed traumatic events are likely to have significant voiding problems and recurring need for further interventions. Many of these men have significant orthopedic and neurologic injuries, as well. Rehabilitation requires reconstruction of the urinary tract in a manner that does not interfere with the healing process.

Relevant Anatomy

The male urethra may be divided into 2 portions. The posterior urethra includes the prostatic urethra, which extends from the bladder neck through the prostate gland. It then joins the membranous urethra, which lies between the prostatic apex and the perineal membrane. The anterior urethra begins at that point and includes 3 segments. The bulbar urethra courses through the proximal corpus spongiosum muscles to reach the penile urethra. The penile urethra then extends through the pendulous portion of the penis to the final segment, the fossa navicularis. The fossa navicularis is invested by the spongy tissue of the glans penis. See image below.

 

Male urethral anatomy Male urethral anatomy

Potential areas for injury can be deduced from further study of the urethral anatomy. The membranous urethra is prone to injury from pelvic fracture because the puboprostatic ligaments fix the apex of the prostate gland to the bony pelvis and thus cause shearing of the urethra when the pelvis is displaced. The bulbar urethra is susceptible to blunt force injuries because of its path along the perineum. Straddle-type injuries from falls or kicks to the perineal area can result in bulbar trauma. Conversely, the penile urethra is less likely to be injured from external violence because of its mobility, but iatrogenic injury from catheterization or manipulation can occur, which is also possible in the fossa navicularis.

Pathophysiology

Injury to the posterior urethra occurs when a shearing force is applied at the prostatomembranous junction in blunt pelvic trauma. The prostatic urethra is fixed in position because of the attachments of the puboprostatic ligaments. Displacement of the bony pelvis from a fracture type injury thus leads to either tearing or stretching of the membranous urethra.[1]

Anterior urethral injury most often results from a blunt force blow to the perineum, producing a crushing effect on the tissues of the urethra. The initial injuries are often ignored by the patient, and urethral injury manifests years later as a stricture. The stricture results from scarring induced by ischemia at the site of the injury. Penetrating injuries also occur in the anterior urethra as a result of external violence.

Etiology

As with many traumatic events, the etiology of a urethral injury can be classified as blunt or penetrating. In the posterior urethra, blunt injuries are almost always related to massive deceleration events such as falls from some distance or vehicular collisions. These patients most often have a pelvic fracture involving the anterior pelvis.[2]

Blunt injury to the anterior urethra most often results from a blow to the bulbar segment such as occurs when straddling an object or from direct strikes or kicks to the perineum.[3] Blunt anterior urethral trauma is sometimes observed in the penile urethra in the setting of penile fracture.

Penetrating trauma most often occurs to the penile urethra. Etiologies include animal bites[4] , gunshot and stab wounds. Insertion of foreign bodies is another rare cause of anterior injury. It is usually a result of autoerotic stimulation or may be associated with psychiatric disorders.[5]

Iatrogenic injuries to the urethra occur when difficult urethral catheterization leads to mucosal injury with subsequent scarring and stricture formation. Catheter placement is the most common cause of iatrogenic urethral trauma. Iatrogenic urethral injuries also occur after radical prostatectomy, pelvic radiotherapy, and other abdominopelvic surgery.[6]  

Epidemiology

Posterior urethral injuries are most commonly associated with pelvic fracture, with an incidence of 5%-10%. With an annual rate of 20 pelvic fractures per 100,000 population, these injuries are not uncommon.[7] Anterior urethral injuries are less commonly diagnosed emergently; thus, the actual incidence is difficult to determine. However, many men with bulbar urethral strictures recall an antecedent perineal blunt injury or straddle injury, making the true frequency of anterior urethral injury much higher. Penetrating injury to the urethra is rare, with major trauma centers reporting only a few per year.

Prognosis

Men with urethral injuries have an excellent prognosis when managed correctly. Problems arise if a urethral injury is unrecognized and the urethra is further damaged by attempts at blind catheterization. In those instances, future reconstruction may be compromised and recurrent stricture rates rise. When managed well, these men have an excellent chance of becoming totally rehabilitated from a urinary standpoint.

Continence rates approach 100% in all series, particularly if the bladder neck is not involved. Potency status is probably related to the extent of the injury itself rather than the management of the problem. Several series have demonstrated only a small group of men losing erectile capabilities following the urethroplasty when they are potent following the actual injury.[8]

The main complication following reconstruction of posterior injuries is recurrent stricture. When managed with standard urethroplasty techniques, recurrent stricture requiring major repeat operation should be observed in only 1%-2% of patients, although 10%-15% may require either dilation or incision of a short recurrence.[9]

Endoscopic realignment by experienced physicians appears to produce similar results. When performed at 5-7 days postinjury, rare infectious complications occur despite the presence of the organized pelvic hematoma.

Complications of reconstruction of anterior urethral injuries are similar to those observed in posterior urethral repairs.

 

Presentation

History

Diagnosis of urethral injuries requires a reasonably high index of suspicion. Urethral injury should be suspected in the setting of pelvic fracture, traumatic catheterization, straddle injuries, or any penetrating injury near the urethra. Symptoms include hematuria or inability to void. 

 

 

Physical Examination

Physical examination may reveal blood at the meatus or a high-riding prostate gland upon rectal examination. Extravasation of blood along the fascial planes of the perineum is another indication of injury to the urethra. "Pie in the sky" findings revealed by cystography usually indicate urethral disruption.

 

Workup

Imaging Studies

Computed tomography and magnetic resonance imaging

These studies have become even more important as trauma services rely more on initial computed tomography (CT) scanning as the major imaging modality. The "trauma" CT may well miss lower urinary tract injuries to the urethra and bladder and thus any suspicion for urethral injury should lead to performance of these studies in addition to any others.[10]  

Joshi et al report on their protocol of performing magnetic resonance imaging scans to assess urethral injury in patients with pelvic fractures. These authors note that contrary to conventional belief, the membranous sphincter is often intact and the injury is instead at the membranobulbar junction, suggesting that surgical reconstruction can be undertaken, preserving sphincter mechanisms and improving postoperative continence.[11]

Retrograde urethrography

Retrograde urethrography is the standard imaging study for the diagnosis of urethral injury. It is performed using gentle injection of 20-30 mL of contrast into the urethra while occluding the meatus, with a balloon of a Foley catheter inflated in the fossa navicularis. Films should be taken in a 30°-oblique position, unless this is not possible because of the severity of the pelvic fractures and associated patient discomfort. 

A urethrogram allows for identification of the site of injury and assessment of the extent of any injury. Any extravasation outside the urethra is pathognomonic for urethral injury. The distinction between a complete and partial rupture is not always clear. A typical image for incomplete rupture shows extravasation from the urethra which occurs while the bladder is still filling. A complete rupture is suggested by massive extravasation without bladder filling.[5]

Urethrogram demonstrating partial urethral disrupt Urethrogram demonstrating partial urethral disruption.
Urethrogram demonstrating complete urethral disrup Urethrogram demonstrating complete urethral disruption.

Cystography

Static cystography allows for concurrent bladder injury to be excluded in the acute setting. When a delayed repair is being considered, voiding cystography (performed through the suprapubic catheter) demonstrates the bladder neck and prostatic urethral anatomy and allows for proper surgical planning.

Cystoscopy

Cystoscopy can be a valuable adjunct in the evaluation of a male urethral injury. In the acute setting, the feasibility of early endoscopic realignment can be determined (see Treatment). In the delayed setting, the quality of the urethra can be evaluated for surgical repair. When cystoscopy is combined with retrograde urethrography and cystography, a more accurate estimation of stricture length can be made, facilitating decisions in operative strategy.

Flexible cystoscopy is preferred over retrograde urethrography in suspected penile fracture-associated urethral injury.[5]

Staging

Classification of urethral injuries is based on location and retrograde urethrography[5] :

  • Anterior urethra partial disruption
  • Anterior urethra complete disruption
  • Posterior urethra stretched but intact
  • Posterior urethra partial disruption
  • Posterior urethra complete disruption
  • Posterior urethra complex (involves bladder neck and/or rectum)
 

Treatment

Approach Considerations

When faced with urethral trauma, initial management decisions must be made in the context of other injuries and patient stability. These patients often have multiple injuries, and management must be coordinated with other specialists, usually trauma, critical care, and orthopedic specialists. Life-threatening injuries must be corrected first in any trauma algorithm.[12]   

Initial emergent treatment remains controversial, but mainstays of therapy include drainage of the urinary bladder, often with placement of a suprapubic catheter (SPT) and primary endoscopic realignment of the urethra if possible.

Immediate urethral repair is relatively contraindicated because life-threatening injuries must be corrected first in any trauma algorithm. Urethral repair should be undertaken after the patient has stabilized, when hemorrhage is less of a concern. If open repair is planned, it is better to allow the pelvic hematoma to subside prior to the procedure.

Penetrating anterior urethral injuries should be explored; however, defects longer than 2 cm in the bulbar urethra and longer than 1.5 cm in the penile urethra should never be emergently repaired. They should be reconstructed at an interval following the injury to allow for resolution of other injuries and proper planning of the tissue transfers required for the repair.[13]

 

Surgical Therapy

The traditional intervention for men with posterior urethral injury secondary to pelvic fracture is placement of a suprapubic catheter for bladder drainage and subsequent delayed repair. This is the safest approach because it establishes urinary drainage and does not require either urethral manipulation or entrance into the hematoma caused by the fracture of the pelvis. This allows a formal repair to be carried out several weeks later under controlled circumstances and after resolution of the hematoma. The suprapubic catheter can be safely placed either percutaneously or via an open approach with a small incision. Ultrasound guidance can aid in the percutaneous approach. Some advocate immediate realignment through a number of different techniques, although much controversy exists on this topic.[14]

Ultimate repair of the posterior urethral injury can be performed 6-12 weeks after the event, after the pelvic hematoma has resolved and the patient's orthopedic injuries have stabilized. It is often carried out via a perineal approach, and repair consists of mobilizing the urethra distally to allow a direct anastomosis after excision of the stricture.

To prevent tension on the anastomosis, the distal urethra can be mobilized to the penoscrotal junction. Further length can be achieved with division of the septum between the corpora cavernosa and with inferior pubectomy. A urethral catheter is left indwelling to stent the repair, and the suprapubic catheter may be removed. Transpubic approaches for this repair have also been described and may be useful in men with fistulous tracts complicating a membranous urethral injury. Combining a perineal and abdominal approach with pubectomy provides maximum exposure of the prostatic apex.[15, 16, 17, 18]

Early realignment of posterior urethral injuries is also a treatment option. This has been performed at the time of injury, using interlocking sounds or by passage of catheters from both retrograde and antegrade approaches. Also, direct suture repair has been attempted in the immediate postinjury period. Another approach could be careful insertion of a urethral catheter under fluoroscopic guidance by a urologist experienced in that approach. These approaches have the disadvantage of possible entrance into and contamination of the pelvic hematoma with ensuing hemorrhage and sepsis.

Early endoscopic realignment (within 1 week postinjury) using a combined transurethral and percutaneous transvesical approach may be safer. If performed 5-7 days postinjury, the pelvic hematoma has stabilized and hemorrhage is less of a concern. The patient's overall condition has usually improved by this time, and sepsis is less of a concern.[19, 12] Ultimate outcomes and benefits of this approach remain controversial.[20, 21]

Bulbar urethral injuries often manifest months to years following blunt perineal trauma. The presentation for these injuries is often that of decreased stream and voiding symptoms. The diagnosis of urethral stricture is then made with urethrography and cystoscopy. These strictures may be managed with excision of the stricture and end-to-end anastomosis via a perineal approach. Most are short (< 2 cm). Longer strictures may require flaps (penile fasciocutaneous) or grafts (buccal mucosa) to achieve a tensionless anastomosis.[22, 23]

Penetrating anterior urethral injuries should be explored. The area of injury should be examined, and devitalized tissue should be debrided carefully to minimize tissue loss. Defects of up to 2 cm in the bulbar urethra and up to 1.5 cm in the penile urethra can be repaired primarily via a direct anastomosis over a catheter with fine absorbable suture. This is the preferred method of repair for these injuries. Longer defects should never be repaired emergently; they should be reconstructed at an interval following the injury to allow for resolution of other injuries and proper planning of the tissue transfers required for the repair. Urinary diversion can be accomplished with a suprapubic catheter during this interval.[24]

Preoperative Details

In all urethral injuries, the location of the injury should be localized with repeat urethrography, antegrade cystogram through the suprapubic tube, and cystoscopy, if needed. If an open perineal repair is performed, the patient should be positioned in an exaggerated lithotomy position with the legs well padded. Deep venous thrombosis prophylaxis with compression stockings is preferred. Access to the bladder via the indwelling suprapubic catheter is also useful.

If endoscopic realignment is contemplated, a more relaxed lithotomy position is better. A wide variety of endoscopes, graspers, and wires is needed. This procedure is often best performed using a C-arm for fluoroscopy because of the ease in obtaining oblique views.

Exploration for penile urethral injuries can be performed in the supine position, although lithotomy may also be helpful if dissection must be carried down into the scrotum. Flexible cystoscopy may also be of assistance during the procedure.

Intraoperative Details

In open urethral reconstruction, careful dissection of the urethra is important. Anastomoses must be performed in a mucosa-to-mucosa fashion to ensure proper healing without further scarring. All anastomoses should be performed over a catheter for stenting purposes.

Excessive mobilization of the urethra must be avoided to prevent tethering of the penis. If a gap of more than 2 cm must be bridged, performing a flap procedure rather than placing the anastomosis under tension or tethering the penis, which causes curvature, is better. This should be performed as part of a delayed reconstruction and not in the acute setting.

Local flaps should be handled meticulously to avoid devascularization. Buccal mucosal grafts should be harvested from the inner cheek and carefully tubularized over a catheter. These may also be effectively used in an onlay fashion.

In endoscopic realignment, having 2 urologists working simultaneously with fluoroscopy is preferable. One should pass a scope transurethrally and the other should work via the suprapubic tract. Often, injuries thought to be a complete disruption are found to be partial disruptions, and the intact mucosa can be followed into the bladder. If the scopes can meet and pass wires to one another, then a catheter may be placed transurethrally over the wire.

Postoperative Details

In open repairs, the suprapubic catheter may be removed immediately, leaving the urethral catheter for drainage and stenting. The patient may be mobilized on the day following surgery and discharged when tolerating a diet. Antibiotics are maintained for 2 weeks, and the catheter is removed after 4 weeks. A similar pattern is followed for the endoscopic procedure except that the urethral catheter is left indwelling for 6 weeks. After either type of procedure, retrograde urethrography may be indicated to ensure extravasation is not occurring prior to catheter removal. This is particularly true for patients with poor wound healing such as people with diabetes.

Follow-up

In all instances of urethral injury, follow-up should include assessment of the patient's voiding history, continence status, and potency. Undoubtedly, follow-up should be life-long, although in the trauma population this is often difficult to achieve. Repeat cystourethrography and cystoscopy should be used whenever changes occur following reconstruction.

 

Guidelines

Guidelines Summary

The American Urology Association (AUA) guidelines for diagnosis and management of genitourinary injuries were amended in 2017 to reflect literature that was released since the original publication in 2014. Key recommendations for the ureteral trauma include[25] :

  • Retrograde urethrography should be performed in patients with blood at the urethral meatus after pelvic trauma.
  • Prompt urinary drainage should be established in patients with either pelvic fracture associated urethral injury or with straddle injury to the anterior urethra.
  • Suprapubic tubes (SPTs) may be placed in patients undergoing open reduction internal fixation (ORIF) for pelvic fracture.
  • Primary realignment (PR) may be performed in hemodynamically stable patients with pelvic fracture associated urethral injury. Prolonged attempts at endoscopic realignment should not be performed.
  • Patients should be monitored for complications (e.g., stricture formation, erectile dysfunction, incontinence) for at least one year following urethral injury
  • Prompt surgical repair should be performed in patients with uncomplicated penetrating trauma of the anterior urethra.

In 2016, the American Urology Association (AUA) released guidelines for the diagnosis and treatment of male urethral strictures. For patients with pelvic fracture urethral injury, recommendations include[26] :

  • Use retrograde urethrography with voiding cystourethrogram and/or retrograde + antegrade cystoscopy for preoperative planning of delayed urethroplasty after pelvic fracture urethral injury (PFUI). 
  • Perform delayed urethroplasty instead of delayed endoscopic procedures after urethral obstruction/obliteration due to PFUI. 
  • Definitive urethral reconstruction for PFUI should be planned only after major injuries stabilize and patients can be safely positioned for urethroplasty. 

The 2018 European Association of Urology (EAU) urogenital trauma guidelines includes the following recommendations for diagnosis and management of urethral trauma[5] :

  • Evaluate urethral injuries with flexible cystoscopy and/or retrograde urethrography.
  • Treat blunt anterior urethral injuries by suprapubic diversion.
  • Treat partial posterior urethral ruptures by urethral or suprapubic catheterisation.
  • Perform early endoscopic re-alignment when feasible.
  • Manage complete posterior urethral disruption with suprapubic diversion and deferred (at least three months) urethroplasty.