Traumatic injury to the male anterior urethra, scrotum, and penis

INTRODUCTION — Up to two-thirds of cases of genitourinary (GU) trauma involve the male external genitalia, which includes the anterior urethra, scrotum, and penis. The overall estimation of incidence is difficult to ascertain given the heterogenous etiologies.

Identification and treatment of traumatic injury to the male external genitalia requires anatomic knowledge and timely diagnostic evaluation and treatment to avoid unwanted outcomes, including urethral stricture, sexual dysfunction, and/or secondary psychosocial stressors. Coordination of care among urologists, general/trauma surgeons, orthopedics, and other services can be essential to improve overall outcomes.

Trauma injury to the penis, scrotum, or perineal region can be associated with injury to the anterior urethra, while pelvic fractures can be associated with injury to either the anterior or posterior urethra (bulbomembranous portion) but are generally regarded as posterior urethral injuries. These are reviewed separately. (See "Posterior urethral injuries and management".)

Traumatic injury to the male external genitalia, including injury to the anterior urethra, scrotum, and penis is reviewed here. Traumatic injury to the female external genitalia is reviewed separately. (See "Evaluation and management of female lower genital tract trauma".)

ANATOMY — Knowledge of the fascial layers of the genitalia and perineum aids genital injury diagnosis and subsequent treatment. Knowledge of the anatomy of the urethra, which conveys urine from the bladder to the exterior of the body, is also important since management differs based upon urethral injury location. By convention, the surfaces of the penis are defined with the penis extended cranially and the urethra located ventrally.

Colles', dartos, and Scarpa's fascia are continuous superficial fascial layers of the perineum, penis/scrotum, and anterior abdominal wall, respectively (figure 1). The layers of the scrotum are shown in the figure (figure 2). The perineal membrane is a strong layer of fascia at the urogenital triangle that stretches between the ischiopubic rami and lies between the prostate above and membranous urethra below. Injury to the perineal membrane following a shearing force can completely or partially avulse the urethra (bulbomembranous portion) from the prostate apex.

The tunica albuginea is a tough layer of fibrous connective tissue composed of inner and outer circular fibers encircling the corpora cavernosa and corpus spongiosum of the penis (figure 3). The tunica albuginea is weakest ventrally where the urethral and corporal bodies lie next to one another.

The male urethra is divided into two segments: the posterior urethra and the anterior urethra (figure 4).

●The anterior urethra includes the bulbar urethra, the pendulous urethra, and the fossa navicularis. The suspensory ligament of the penis delineates the pendulous and bulbar urethra. The anterior urethra consists of an epithelial layer that is surrounded by the corpus spongiosum. The spongiosum is concentrically located around the urethra in the distal pendulous urethra (figure 5). In the bulbar urethra, it becomes eccentrically located with a larger component on the ventral surface.

●The posterior urethra includes the bladder neck, the prostatic urethra, and the membranous urethra. The spongiosum is absent around the posterior urethra.

The male urethra is supplied by the bulbourethral arteries (figure 6), which are branches of the internal pudendal artery; venous drainage is via the deep dorsal vein and circumflex veins.

MECHANISMS OF INJURY — Injuries to the male external genitalia include typical blunt or penetrating mechanisms (ie, motor vehicle accident, gunshot) that can involve the penis, scrotum, and/or testicle(s). Injury to the anterior urethra is commonly associated. Other blunt (straddle injury, zipper injury) and penetrating mechanisms (animal bites) are less common but do occur. The perineum/external genitalia are commonly burned in conjunction with burns to the remainder of the body; isolated burn injury to the male genitalia is rare. Specific penile injuries, such as penile fracture and penile amputation, are also rare.

●Blunt trauma

•Testicular/epididymal injury – Blunt scrotal trauma can cause testicular tunica albuginea rupture, testicle contusion, testicle hematoma, testicle torsion, and epididymal injury. Although testicular/epididymal injury can occur following blunt or penetrating injury, blunt mechanisms are most common. Scrotal ecchymosis and pain are common physical exam findings. When blood is seen at the urethral meatus after blunt pelvic or genital trauma, retrograde urethrography is indicated to evaluate for urethral injury [1,2]. (See 'Anterior urethra' below.)

•Degloving – Blunt injury can result in partial, circumferential, or complete penile skin loss (ie, degloving). Scrotal degloving can also occur.

•Straddle injury – Straddle injuries are caused by direct trauma to the perineum and compress the bulbar urethra against the pubic bone. Straddle injury is the most common cause of anterior urethral injury. The clinical manifestations of these injuries can present acutely if there are accompanying clinical symptoms (ie, hematuria, hematoma) or in a delayed fashion following obstructive voiding secondary to a urethral stricture. (See "Straddle injuries in children: Evaluation and management".)

•Zipper injury – The majority of zipper injuries occur in children. It can also occur in adults with impaired cognition, or occasionally during zipper closure by a caretaker, who may have become distracted. When they occur, patients are extremely reluctant to come for care, which can cause delays in presentation. Zipper injuries are presented separately. (See "Management of zipper entrapment injuries".)

•Pelvic fracture – Urethral injuries in the setting of a pelvic fracture are associated with mechanisms that rupture the puboprostatic ligament with or without shearing forces to the perineal membrane. These most commonly affect the bulbomembranous urethra. Inferior pubic rami fractures, symphysis pubis diastasis, and sacroiliac joint diastasis are pelvic fractures more commonly associated with concomitant urethral injury [3]. Urethral injuries associated with pelvic fractures are reviewed separately. (See "Posterior urethral injuries and management".)

●Penetrating trauma – Penetrating injuries more commonly include gunshot and stab wounds, but animal bites and other missile injuries (shotgun) can also occur. Diagnostic evaluation of the urethra is recommended following any penetrating injury to the penis to rule out injury, which occurs in 11 to 29 percent of cases. (See 'Anterior urethra' below.)

•Gunshot/stab – Penetrating penile injuries typically occur following a gunshot wound with damage to the penile skin, corporal bodies, and/or urethra [4]. There is a high correlation with associated injuries to the rectum, scrotum/testicles, femoral vessels, surrounding soft tissue, and/or the pelvic bones (picture 1). Thus, clinicians should be mindful to perform a thorough examination of wounds for possible associated injuries.

•Animal bites – Animal bites involving the male external genitalia are most commonly due to a dog bite involving children. Injury severity is directly correlated with dog size, breed, and any aggressiveness training. Human and dog bites to the genitalia are polymicrobial in nature, and delayed presentation is associated with an increased risk of infection. Among dog bites, Pasteurella species are the most common isolates [5]. Viral transmission of HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV) increases the complexity of human bites. (See "Animal bites (dogs, cats, and other mammals): Evaluation and management" and "Human bites: Evaluation and management", section on 'Spectrum of antibiotic coverage'.)

●Burns – Burns to the perineum and genitalia occur in approximately 3 to 13 percent of all patients sustaining burns. Isolated burns to the perineum and/or genitalia are rare [6,7]. Flames (24 to 77 percent), hot liquids (15 to 64 percent), and chemical agents (8 to 16 percent) are the most common agents [6,8]. (See "Principles of burn reconstruction: Perineum and genitalia".)

●Penile fracture – Penile fracture is an uncommon injury that can occur when the tunica albuginea of the corporal cavernosa ruptures. Penile fracture occurs in the erect state when the circular tunica albuginea fibers are stretched and subsequently thinned out. The tunica is weakest ventrally where the urethral and corporal bodies lie next to one another. The close proximity to the corpus spongiosum can also result in concomitant urethral injury in approximately 20 percent of patients [9-14]. Penile fracture can occur following sexual intercourse in association with bending of the penis during attempted penetration. Aggressive bending of the erect penis downward to achieve rapid penile detumescence (ie, taghaandan) can also lead to penile fracture. Diagnostic evaluation of the urethra is recommended following a confirmed diagnosis of penile fracture. About 20 percent are associated with concomitant anterior urethral injury [15-25]. (See 'Anterior urethra' below.)

●Penile amputation – Penile amputation is a rare injury that is most commonly due to self-mutilation and associated extreme mental illness [26]. Associated psychiatric disorders and/or substance abuse issues should be sought and addressed. Prehospital care for the amputated penile stump is important, ideally using a double bag technique. The amputated stump should be cleaned with saline, wrapped in saline gauze, and placed in an inner plastic bag (eg, Ziploc). The outer bag should be filled with ice/slush to avoid direct thermal injury.

CLINICAL EVALUATION — The clinical evaluation of trauma to the external male genitalia requires a systematic approach to minimize the potential for missed injury, evaluating the skin, penis, testicles, and associated structures in turn. Due to the close association with the urethra, urethral imaging or endoscopy is recommended for all but the most superficial injuries (see 'Anterior urethra' below). The examination should also include evaluation for potential concomitant injuries (eg, rectal), and if identified, these should be inspected during the initial exam (unless associated with unstable pelvic fracture). (See "Traumatic gastrointestinal injury in the adult patient" and "Severe pelvic fracture in the adult trauma patient".)

Skin/soft tissue injury — The presence of perineal bruising should be noted and, in conjunction with an appropriate history, may indicate a straddle injury. If Colles' fascia is intact, this will appear as a butterfly hematoma (picture 2). The hematoma can extend to the dartos fascia lining the scrotum if there is continued bleeding. Testicular rupture may be suggested by scrotal ecchymosis and swelling or difficulty in identifying the contours of the testicle on physical exam. Similar findings may be present in association with penetrating injury. With scrotal skin avulsions, careful washout and examination for penetration of the scrotal dartos fascia is imperative. Penetration of the dartos fascia should prompt further scrotal exploration in the operating room to assess for testicular and/or epididymal injury. (See 'Scrotum' below.)

Penile skin injuries are best evaluated by careful clinical inspection. Any areas of complete circumferential skin loss should be noted. Intact penile shaft skin distal to completely circumferential skin loss can result in chronic lymphedema, prompting recommendations to remove distal skin. Classic features of penile fracture are a loud "popping sound" followed by rapid penile detumescence, penile ecchymosis, pain, and/or difficulty urinating [15-17,27-35]. Blood contained within an intact Buck's fascia (the deep fascia layer surrounding the corpora cavernosa and corpus spongiosum) results in an "eggplant" deformity, as blood is contained over the site of penile fracture (picture 3). If Buck's fascia is penetrated, blood will extravasate below the superficial fascial planes of the penoscrotal dartos fascia, resulting in ecchymosis along the penis and scrotum. Clinical examination alone may be sufficient to identify if the tunica albuginea has been violated; however, additional diagnostic evaluation may be necessary to make this determination. (See 'Penis' below.)

Suspicion for anterior urethral injury — Anterior urethral injures may be due to blunt (eg, straddle injuries) or penetrating trauma (gunshot, shotgun, knife) to the perineum, or due to laceration or crush of the penis, including penile amputation. When anterior urethral injury is suspected, diagnostic evaluation (retrograde urethrogram, cystoscopy) is indicated. (See 'Diagnostic evaluation' below.)

With straddle injuries (picture 2), the bulbar urethra is compressed against the pubic bone, resulting in partial or complete injury. Bulbar urethra straddle injuries are often isolated and less associated with pelvic fracture. Other causes of anterior urethral injury include sexual trauma, burns, and bites. Although urethral injury is commonly associated with penetrating mechanisms, penile injury (blunt or penetrating) can occur in the absence of urethral injury.

Blood at the urethral meatus is the most common finding of associated anterior urethral injury, but this finding is highly variable, present in 37 to 93 percent of acute urethral injuries [36]. Other clinical findings of anterior urethral injury include difficulty voiding and perineal/genital ecchymosis.

DIAGNOSTIC EVALUATION — The diagnostic evaluation of lower genitourinary tract injuries is based on the presenting clinical signs and physical examination, the clinical status of the patient, and mechanism of injury (algorithm 1).

Anterior urethra — All but the most superficial injuries to the external male genitalia (perineum, scrotum, penis) should prompt evaluation for the presence of urethral injury [37]. The diagnosis of anterior urethral injury (partial, complete) can be made by retrograde urethrogram or urethroscopy. Blind catheter passage prior to retrograde urethrogram is generally discouraged, though in selected situations (eg, unstable patient), a blind attempt can be performed by an experienced provider, if deemed necessary. (See 'Catheter drainage' below.)

A retrograde urethrogram will only assess the anterior urethra since the external sphincter, which lies at the junction of the bulbar and membranous urethra, will reflexively close with passage of the contrast material (image 1). Consequently, the posterior urethra cannot be reliably assessed with retrograde urethrogram. Nevertheless, most injuries in the bulbomembranous region will be diagnosed during retrograde urethrogram.

For retrograde urethrogram, the patient should be positioned obliquely at approximately 45° with the top leg straight and bottom leg bent to provide a complete view of the urethra. The anterior urethra is not well seen with the patient in the anterior-posterior position, and diagnostic sensitivity is reduced (image 2).

To perform a retrograde urethrogram, a 12-French urethral catheter is placed into the fossa navicularis. The penis is placed on gentle traction, and 20 mL of undiluted water-soluble contrast material is injected with the image acquired. Although blind urethral catheter passage prior to retrograde urethrogram should be avoided, if a urethral catheter has already been successfully placed, then the contrast can be injected into a small catheter (ie, 3 to 8 Fr feeding tube or angiocatheter) that is placed between the existing urethral catheter and fossa navicularis (ie, pericatheter retrograde urethrogram) [38].

Scrotum — In the absence of scrotal dartos penetration mandating scrotal exploration, scrotal ultrasound can be a useful adjunct following blunt scrotal trauma when clinical findings suggest possible testicle/epididymal injury (figure 2), particularly when a large scrotal hematoma hinders the clinical exam. If associated scrotal swelling or pain during ultrasound precludes accurate assessment of the dartos fascia, operative exploration is recommended to rule out injury to the testicle or epididymis. (See 'Indications for surgical exploration' below.)

Findings on ultrasonography include loss of testicular contour from loss of the testicular lining (ie, tunica albuginea) and heterogeneity of the testicle parenchyma [39,40]. The presence of a hematocele, testicular hematoma, or testicular rupture can result in ischemic atrophy of the testicles with ensuing chronic orchialgia and/or infection, which may necessitate delayed orchiectomy. As such, scrotal exploration with repair of the injury is recommended (picture 4). (See 'Testicular repair/orchiectomy' below.)

Penis — For suspected blunt penile fracture, imaging studies can be useful when there are equivocal findings (ie, unclear or partial loss of erections with associated penile ecchymosis and/or edema) [18]. Demonstration of disruption of the tunica albuginea on imaging is indicative of corpora cavernosa injury. Penile ultrasound is generally recommended given that the exam is widely available and inexpensive [41,42]. While coronal T1-weighted magnetic resonance (MR) imaging has excellent sensitivity, it is less cost effective [28,43].

Injury grading — For urethral injury, knowledge of the injury location and its extent helps guide management. The American Association for the Surgery of Trauma (AAST) urethral injury grading scale provides a descriptive analysis of injury severity (table 1). This and a number of other classification systems can be difficult to use based on fluoroscopic imaging. As such, a more practical staging system was proposed following a consensus panel organized by the Society of International Urology [44]. This classification system stratifies urethral injuries by location as either anterior urethral (penile, bulbar urethra) or posterior urethral (prostatic, membranous urethra) injury, and whether the injury is partial or complete. Posterior urethral injuries with involvement of the bladder neck, or associated injuries to the rectum and/or vagina are designated as complex injuries.

For testicular, scrotal, and penile injuries, a simple clinical description of the injury often suffices in lieu of using the respective AAST organ injury scales (table 2 and table 3 and table 4) [45].

NONOPERATIVE MANAGEMENT — In the setting of other severe injuries, definitive management of traumatic injuries to the male external genitalia is often delayed until other more urgent injuries are successfully managed. Following acute urethral injury, timely urinary drainage is necessary to avoid infection, urethrocutaneous fistula, urethral diverticulum, urethral stricture, and (rarely) necrotizing soft tissue infection. (See 'Catheter drainage' below.)

Focal penile soft tissue injury without skin loss and without injury to the tunica albuginea of the corporal bodies can generally be managed nonoperatively. Nonoperative management is also recommended for most anterior urethral contusions, but certain clinical scenarios can mandate open exploration and repair following acute injury (eg, persistent bleeding following straddle injury (picture 2)). Penile fracture should be managed surgically in lieu of observation as there have been reports of erectile dysfunction and penile curvature following nonsurgical care; surgical repair is rarely associated with erectile dysfunction or penile curvature [46]. (See 'Penile repair/replantation' below.)

For blunt scrotal injury, if scrotal ultrasound and/or clinical exam is not concerning for testicular injury, then initial nonoperative management is appropriate. However, surgical exploration, which is technically easily performed, may be needed due to persistent pain, persistent hematoma, or development of infection. Early compared with delayed exploration and repair of a testicular injury is associated with increased testicular salvage, which preserves hormonal function and fertility. Delayed repair of testicle injury increases the rate of future orchiectomy by three- to eightfold [47-49]. In one study, orchiectomy was required in 9 percent who underwent early exploration compared with 45 percent for delayed exploration [49]. (See 'Testicular repair/orchiectomy' below.)

Superficial and superficial partial-thickness burn injuries to the male genitalia may only require topical antimicrobial agents (eg, 1% silver sulfadiazine). Deep partial-thickness burns that do not heal within three weeks should be treated as a full-thickness burn with excision and skin grafting. (See "Topical agents and dressings for local burn wound care", section on 'Antimicrobial agents' and "Principles of burn reconstruction: Perineum and genitalia".)

Catheter drainage — The acute management of most blunt anterior urethral injuries involves bladder drainage in the form of a urethral catheter (algorithm 1), with delayed repair, as needed. If a urethral catheter cannot be placed, cystoscopy can be used as an aid. Following complete anterior urethral disruption, a suprapubic catheter may be necessary.

Immediate operative repair of blunt anterior urethral injury is contraindicated due to the indistinct nature of the injury border, which may lead to excessive urethral debridement. In addition, definitive repair can be challenging in acute settings; therefore, most surgeons advocate waiting three months before definitive repair. For straddle injuries, catheter placement helps minimize urinary extravasation [50]. While immediate repair is rarely necessary to control persistent bleeding, in such situations, evacuation of the hematoma and control of the bleeding source can be useful.

For uncomplicated (focal) penetrating urethral injury, catheter drainage is provided after repair. For extensive penetrating injuries (ie, significant tissue loss), initial catheter drainage with delayed repair is recommended.

For full-thickness burns to the glans penis and/or ventral penile shaft, a suprapubic catheter should be considered rather than urethral catheterization to reduce the potential for traumatic hypospadias, which can occur as a consequence of pressure necrosis from the indwelling urethral catheter. If placement is not possible due to the extent of the burn to the suprapubic area, then a small-caliber urethral catheter should be secured dorsally to reduce downward (ventral) pressure on the urethra. The urinary catheter should be removed as early as possible to avoid added morbidity.

A peri-catheter retrograde urethrogram is recommended one to two weeks after urethral injury to assess for urethral healing. If there is persistent urinary extravasation, then urethral drainage is continued until urine extravasation has resolved. If the patient is unable to void subsequently as a result of progression to a urethral stricture, a suprapubic tube may become necessary. The suprapubic tube is left in place until definitive surgery. (See 'Surgery' below.)

Antibiotics — Following initial wound irrigation and debridement, topical antimicrobial agents (eg, cephalosporins) can be useful to help reduce infection, if the wound was contaminated.

Following animal and human bites, intravenous antimicrobial therapy is recommended (table 5 and table 6). (See "Human bites: Evaluation and management", section on 'Management' and "Animal bites (dogs, cats, and other mammals): Evaluation and management", section on 'Management'.)

In general, the risk of contracting HIV, hepatitis B, or hepatitis C from a human bite is negligible unless blood exposure has also occurred. If exposure is a possibility, then prophylaxis may be appropriate, and is discussed separately. (See "Management of nonoccupational exposures to HIV and hepatitis B and C in adults".)

SURGERY

Indications for surgical exploration — Surgical exploration is indicated for the following:

●Positive findings of tunica albuginea rupture or scrotal dartos penetration on clinical examination or imaging studies.

●Penetrating injuries to the penis/perineum (including bite wounds) to evaluate/repair possible concomitant anterior urethral injury.

●Penetrating injuries to the scrotum to evaluate/repair the testicle since more than half will have testicular rupture [51].

●Blunt scrotal injury with abnormalities on ultrasound or clinical findings concerning for injury in spite of apparently normal imaging or persistent pain, persistent hematoma, or development of infection during a period of observational management.

●Penile fracture should be managed surgically to prevent erectile dysfunction and penile curvature [52].

●Penile amputation is rare, but when it occurs, surgical replantation, if possible, needs to be performed urgently for the best possible outcome.

Wound cleansing/debridement — With concomitant soft tissue injury, the wound is cleansed and debrided to remove nonviable tissue. Violation of the tunica albuginea or scrotal dartos indicates the need for further exploration of the penis or scrotum, respectively. For soft tissue wounds that are not closed, the wound can be dressed using saline wet-to-dry dressing, until the wound bed is appropriate for closure or reconstruction. (See "Basic principles of wound management".)

Skin grafting/flap reconstruction — Skin grafting or other types of flap reconstruction may be needed following penetrating trauma, burns to the male external genitalia, blunt injury leading to extensive tissue necrosis, and to manage complications related to the trauma, such as complex abscess or necrotizing fasciitis. (See "Skin autografting" and "Overview of flaps for soft tissue reconstruction" and "Principles of burn reconstruction: Perineum and genitalia".)

Prior to skin grafting, any intact penile shaft skin distal to completely circumferential skin loss (ie, degloving) should be excised to avoid distal lymphedema. Similarly, during burn wound excision, any normal penile skin distal to a circumferential full-thickness burn injury should be excised to the coronal sulcus before skin grafting.

Testicular repair/orchiectomy — After delivery of an injured testicle into the operative field, the severity and location of the injury is assessed. Washout of the wound with temporary drain placement may be an option. Otherwise, any extruded seminiferous tubules can be debrided to allow tension-free closure of the testicular tunica albuginea using a running monofilament suture (picture 4). The rates for testicular salvage are higher with immediate exploration and repair, compared with delayed exploration [47-49].

Penile repair/replantation — Penetrating injuries to the penis/perineum, including bite wounds, should be explored to evaluate for possible concomitant anterior urethral injury, which should be repaired immediately rather than staged. (See 'Urethral repair' below.)

Repair of penile fracture is performed by exposing the injured corpus cavernosum through either a ventral midline or circumcision incision and repairing the separated tunica albuginea with absorbable suture (ie, 2-0) [15,29,34,53].

Following penile amputation, replantation can be successful with prompt treatment. Coordination of surgical care between a microvascular surgeon, when available, and a urologist is recommended. Psychiatric consultation is recommended to assess for suicidal ideation. An attempt to reattach the penis should be performed, despite contrary wishes by the patient. The exception is the otherwise fully informed transgender patient.

Microsurgical reanastomosis is necessary to reconnect the dorsal nerve, artery, and vein following penile amputation. Macrosurgical techniques are used for the remainder of the surgery for the urethra, cavernosal artery (if possible), tunica albuginea of the corporal bodies, and penile skin. The location of the penile amputation along the penile shaft can impact the difficulty of microsurgical reanastomosis as the dorsal vessels have a smaller diameter more distally along an amputated penile shaft. Microsurgical replantation is technically challenging; delayed urethral stricture (20 percent), impotence (21 percent), and skin loss (55 percent) are common [26]. Sensation is impaired if microsurgical repair of the dorsal vessels and nerves cannot be accomplished (10 percent preserved for macrosurgical only versus 82 percent preserved for microsurgical repair) [26,54].

Perineal urethrostomy is an option when replantation is not possible because of extensive soft tissue injury or the amputated penile tissue is nonviable. Bladder neck closure with suprapubic catheter placement or creation of a catheterizable urinary reservoir are other options if perineal urethrostomy cannot be performed.

Urethral repair — Immediate surgical closure of anterior urethral injury is recommended for most uncomplicated penetrating injuries. Delayed repair is an option based upon the expertise of the treating surgeon; however, in the acute setting, outcomes of primary repair are generally superior to delayed reconstruction for uncomplicated penetrating injuries.

●For repair of partial penetrating urethral injury, the urethral mucosa is reapproximated using interrupted sutures (5-0 absorbable).

●For repair of circumferential penetrating injury, debridement and mobilization of the urethral ends should allow for a tension-free repair (interrupted 5-0 absorbable suture).

●Bite wounds should be copiously irrigated and debrided with immediate primary closure rather than staged reconstruction.

●For extensive penetrating urethral injury (ie, significant tissue loss (picture 5)), urethral diversion via a suprapubic catheter should be considered with plans for delayed urethral reconstruction.

POSTOPERATIVE CARE AND FOLLOW-UP — Following testicular or penile repair, clinical follow-up examines any associated wounds for progress with healing, assesses voiding function, and can be helpful to provide patient counseling.

Follow-up scrotal ultrasound is recommended to evaluate testicular viability, and fluoroscopic imaging may be used to follow up any injury involving the urethra. Semen analysis can also be offered to anyone interested in future reproduction who have sustained complex genital trauma.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Genitourinary tract trauma in adults".)

SUMMARY AND RECOMMENDATIONS

●Trauma mechanisms – The male external genitalia can be injured due to a variety of traumatic mechanisms, including typical blunt or penetrating mechanisms (ie, motor vehicle accident, gunshot). Other blunt injuries (eg, straddle injury) and penetrating mechanisms (eg, animal bites) are less common but do occur. In addition, the perineum/external genitalia are commonly burned in conjunction with burns to the remainder of the body. Other penile injuries (eg, penile fracture, amputation) are rare. (See 'Mechanisms of injury' above.)

●Clinical and diagnostic evaluation – The clinical evaluation of injury to the male genitalia requires a systematic approach to minimize missed injury. Injuries are initially evaluated by careful clinical inspection. Blood at the urethral meatus is the most common finding of associated urethral injury; other clinical findings include difficulty voiding and perineal/genital ecchymosis. Testicular rupture is suggested by scrotal ecchymosis and swelling or difficulty identifying the contours of the testicle. The presence of perineal bruising may indicate a straddle injury with blunt contusion to the urethra. (See 'Clinical evaluation' above and 'Diagnostic evaluation' above.)

•Testicular injury – Ultrasound is a useful adjunct to the clinical examination following blunt testicle injury or penile fracture. Findings on ultrasonography that indicate a need for further exploration in the operating room include loss of continuity of the tunica albuginea, testicular rupture, heterogeneity of the testicle parenchyma, hematocele, or testicular hematoma. (See 'Scrotum' above.)

•Anterior urethral injury – The diagnosis of anterior urethral injury (partial, complete) can be made by retrograde urethrogram or urethroscopy demonstrating partial or complete occlusion. The appropriate performance of this study is described above. A retrograde urethrogram assesses the anterior urethra since the external urethral sphincter (at the bulbomembranous junction) reflexively closes with passage of the contrast material. Nevertheless, most injuries to the bulbomembranous portion of the anterior urethra (eg, straddle injury, pelvic fracture-associated injury) can be diagnosed with retrograde urethrogram. (See 'Anterior urethra' above.)

●Nonoperative management – Focal penile soft tissue injury without skin loss and without injury to the tunica albuginea of the corporal bodies can generally be managed nonoperatively. Initial nonoperative management is also appropriate for blunt scrotal injury, if clinical exam and/or scrotal ultrasound are not concerning for testicular injury. For associated blunt anterior urethral injuries, bladder drainage via a urethral catheter is also recommended. (See 'Nonoperative management' above.)

●Surgical management – Surgical exploration is indicated for the following (see 'Surgery' above):

•Penetrating injuries to the penis/perineum (including bite wounds) to evaluate/repair possible concomitant anterior urethral injury.

•Penetrating injuries to the scrotum to evaluate/repair the testicle since more than half will have testicular rupture.

•Imaging studies demonstrating tunica albuginea rupture or scrotal dartos penetration.

•Blunt scrotal injury with clinical findings concerning for injury in spite of apparently normal imaging or for persistent pain, persistent hematoma, or development of infection during a period of observational management.

•Penile fracture to prevent erectile dysfunction and penile curvature.

•Penile amputation to evaluate for possible surgical replantation, which needs to be performed urgently for the best possible outcome. If this is not possible, permanent urinary diversion will be needed.

●Timing of surgery – In the setting of other severe injuries, definitive management of traumatic injuries to the male external genitalia is often delayed until other more urgent injuries are successfully managed. Immediate surgical management in the setting of other injuries may be possible for uncomplicated anterior urethral injuries. Exploration with control of bleeding and tissue rearrangement is also an option for penetrating urethral injuries to improve delayed reconstruction. (See 'Surgery' above.)