Penis and Urethra Trauma

Ayman Younis^1,2 and Trevor J. Dorkin¹

¹ Morristown Hospital, Abertawe Bro Morgannwg, University Health Board, Swansea, UK

² Department of Urology, Freeman Hospital, Newcastle upon Tyne Hospitals, Newcastle upon Tyne, London, UK

Abstract

Trauma to the genital tract must be professionally recognised and managed to prevent grave consequences. Genital trauma accounts for up to two‐thirds of all genitourinary trauma and is more common in males than in females. The majority is secondary to blunt injury.

Urethral trauma can be attributed to iatrogenic and noniatrogenic causes. Blunt trauma to the urethra is the most common noniatrogenic cause. Penetrating trauma by gunshot and stabbing are rare but recognised causes of urethral trauma. The urogenital diaphragm divides the male urethra into anterior and posterior urethra. The posterior urethra includes the prostatic and membranous urethra, while the bulbar and pendulous urethra form the anterior urethra. This helps to classify noniatrogenic trauma to the male urethra into anterior and posterior urethral trauma. In females, only the posterior urethra exists and the anterior urethra corresponds to the labia minora.

Frequently, patients with urethral trauma have significant associated orthopaedic injuries and neurological deficits and patients will require initial resuscitation. In these circumstances, management of the urinary tract should be aimed at stabilising the injury and deferring the definitive procedure to a later date to ensure rehabilitation and to minimise surgical complications. This chapter covers the management of penile and scrotal trauma.

Keywords genital trauma; penile trauma; urethral trauma; urethrography

31.1 Penis and Scrotum

Genital trauma account for up to two‐thirds of all genitourinary trauma and is more common in males than in females [1].

31.1.1 Trauma to Foreskin

The foreskin may be injured during minor trauma (e.g. by being jammed in a zip fastener) or may suffer major degloving injuries (e.g. when a vacuum cleaner is used for masturbation) [2]. Industrial or criminal assaults and bites from Homo sapiens or other domestic animals are also seen [3].

All but the most trivial injuries should be taken seriously because mixed infection is apt to lead to cellulitis with more loss of skin. All crushed and nonviable tissue should be excised. No attempt is made at primary closure. Delayed primary or secondary closure is effected after three to four days, during which time intensive antimicrobial therapy is given. With human bites, mixed infection is especially common together with the risk of necrotising fasciitis [3]. Co‐amoxiclav, doxycycline, cephalosporins, and erythromycin are antibiotics of choice with courses for up to two weeks recommended [4, 5]. It is important to liaise with the local microbiology team, especially considering the increasing prevalence of antibiotic resistance and hospital‐acquired infections. With dog bites, there is a risk of rabies infection in certain countries, and consequent treatment and vaccination must be considered.

If there is loss of penile skin, initial wound care simply involves coverage with saline‐soaked gauze dressings. Once any infection has been adequately treated, a full‐thickness skin graft can be applied in cases of extensive skin loss. Split‐thickness skin grafts should be avoided because these can impair expansion during erections, resulting in pain or discomfort.

31.1.2 Penile Trauma

31.1.2.1 Fracture of the Penis

Penile fracture results from trauma to the erect penis during vigorous coitus (most commonly when the partner is on top and the penis slips out of the vagina and forcibly pushed against the perineum or symphysis pubis) or during masturbation. The tunica albuginea splits, often with an audible crack. There is extravasation of blood from the corporal bodies. The corpus spongiosum or urethra may also be torn in 30% cases (Figure 31.1). Patients classically report a popping sound with sudden pain and detumescence during intercourse. A cavernosal defect may sometimes be palpable. The haematoma is usually limited to the penile shaft (the aubergine sign); however, if Buck fascia is ruptured, the haematoma may spread quickly to the lower abdominal wall.

Image described by caption. — **Figure 31.1** Fracture of the penis. (a) The penile skin is pulled back, (b) the tear in the tunica albuginea is repaired, and (c) the skin is replaced (d).

Usually history alone is reliable in diagnosing penile fractures but if in doubt, imaging such as magnetic resonance imaging (MRI) or ultrasound may be useful. The best results follow early exploration, evacuation of the haematoma, and repair of the tunica albuginea [6–8]. A circumferential incision with degloving of the penis is the usual approach to evacuate the haematoma as well as to locate and repair the cavernosal defect. Alternatively, if the injury has been localised with imaging, a linear incision can be made over the injury site. Preoperative urethrography, or more commonly, flexible urethroscopy is useful if urethral injury is suspected.

Conservative management of penile fractures is not recommended because the haematoma may organise, leaving a fibrous plaque in the corpus with the features of Peyronie disease and erectile dysfunction.

31.1.2.2 Amputation of the Penis

Amputation of the penis may occur in an industrial accident, but more often, it follows a domestic or criminal assault or occurs with self‐mutilation. It is occasionally seen after unskilled attempts at circumcision. If the penis can be found, an attempt should be made to reimplant it using microsurgical techniques [8]. This approach may involve microvascular anastomosis of at least one of the penile arteries. There is no need to suture any of the veins; the corpora cavernosa will provide adequate venous return. The urethra is sutured with absorbable sutures over a suitable catheter, and the urine is diverted suprapubically [9]. If the severed penis cannot be found or is unsuitable for reimplantation, the penile wound should be debrided and closed as in partial penectomy. Penile reconstruction or lengthening procedures can be considered at a later date [8].

31.1.2.3 Battery Burn

Severe burns have been caused when an electric battery gets into a baby’s wet napkin [10].

31.1.2.4 Trauma Causing Priapism or Impotence

Cycling may give rise to temporary impotence, which usually recovers spontaneously. Blunt injury has also been reported to cause high‐flow priapism [11, 12].

31.1.3 Scrotal Trauma

31.1.3.1 Lacerations and Avulsions of the Scrotum

As with injuries to the penis, all scrotal injuries require thorough debridement because of the risk of infection. When in doubt, it is wise to delay primary suture for three to four days. This is particularly so in gunshot wounds [13]. If there is any suspicion of urethral injury, a suprapubic catheter is inserted. It is astonishing to see how well the scrotum will regenerate, even though the major part has been avulsed. In the management of these injuries, one can afford to be conservative and postpone skin grafting. If the testes have been exposed by the original injury, they should be temporarily placed in thigh pouches or covered with saline‐soaked dressings until the time of reconstruction.

31.1.3.2 Blunt Trauma

Blunt trauma usually causes injury to the testicles such as dislocation, haematocele, and rupture (see Chapter 38).

31.2 Urethral Trauma

31.2.1 Introduction

Urethral trauma can be attributed to iatrogenic and no‐iatrogenic causes. Blunt trauma to the urethra is the most common noniatrogenic cause. Penetrating trauma by gunshot and stabbing are rare.

The urogenital diaphragm divides the male urethra into anterior and posterior urethra. The posterior urethra includes the prostatic and membranous urethra, whereas the bulbar and pendulous urethra form the anterior urethra. In females, only the posterior urethra exists, and the anterior urethra corresponds to the labia minora.

31.2.2 Noniatrogenic Urethral Injury

31.2.2.1 Male Posterior Urethral Injury

Pelvic fractures as a result of road traffic accidents or falling from heights are commonly associated with posterior urethral injury. The corpora cavernosa are densely attached to the angle between the urethral bulb and the inferior pubic rami and perineal membrane. The prostate gland is firmly attached to the symphysis pubis via the puboprostatic ligaments. In pelvic fractures, severe shearing forces are transmitted to the posterior urethra, leading to complete or incomplete disruption. This is most commonly seen in unstable pelvic fractures, whereby the prostate along with the proximal urethra is wrenched away from the corpora cavernosa which remain joined to the pubic rami (Figures 31.2–31.4). In complete urethral injury, a gap between the severed ends of the urethra may be replaced by fibrous tissue [14]. Although there may be a considerable defect, it is important to note this is not due to loss of urethral tissue; hence, it is possible to undertake direct anastomotic repair to restore urethral continuity.

Many patients with pelvic fractures have other more serious injuries that take priority. In this group of patients, urethral injuries are not life threatening by themselves, but they may result in significant consequences, including urethral strictures, erectile dysfunction, and incontinence [15].

A massive crush injury may lacerate the urethra and rectum (Figure 31.5) [16]. The external urethral sphincter may be destroyed, but the bladder neck is usually intact, except in young boys where the prostate is often torn across. The laceration may also rupture the anal sphincter.

3 Diagrams illustrating the severe crushing injuries which may lacerate urethra and rectum, avulse the adductors, and partially deglove the lower limb. The diagram on the right has 2 arrows indicating crush and shear. — **Figure 31.5** Severe crushing injuries may lacerate urethra and rectum, avulse the adductors, and partially deglove the lower limb.

31.2.2.2 Male Anterior Urethral Injury

Anterior urethral injury is more commonly caused by blunt trauma in comparison to penetrating causes. A fall‐astride or straddle injury to the bulbar urethra or a blow on the perineum forces the urethra up against the inferior edge of the symphysis pubis (Figure 31.6). There may be complete rupture of the corpus spongiosum and urethral wall. Usually, the corpora cavernosa is not injured, and they hold the ends of the corpus spongiosum together (Figure 31.7), so that even if the injury heals with a stenosis, it is always short and easily treated [17, 18] (Figure 31.8). Penile fractures are also associated with anterior urethral injury in 30% of the cases [19]. Less frequent causes of anterior urethral injury include constriction bands used in management of incontinence in paraplegics, gunshot wounds, stab wounds, and dog bites.

Angiogram illustrating urethral injury heals with a stricture. — **Figure 31.8** If the urethral injury heals with a stricture it is a short one.

31.2.2.3 Female Urethral Injury

Urethral injury is rare in females and is attributed to the shortness and mobile nature of the female urethra. Bony fragments resulting from severe pelvic fractures may cause laceration or contusion of the female urethra.

31.2.2.4 Urethral Injury in Children

The urethral injury following pelvic fractures that is seen in boys often differs from that seen in adults. The prostate is so small that the urethra tends to be torn between the bladder and prostate rather than the membranous urethra alone.

31.2.2.5 Clinical Presentation

The diagnosis of urethral injury is suspected by the nature of the injury and the appearance of blood from the urethral meatus or vaginal introitus. Patients may report difficulty voiding or haematuria. Penile haematoma or swelling may develop. In anterior urethral injuries, the pattern of the penile haematoma may give a clue to the extent of the injury. Haematoma confined to the penile shaft suggests an intact Buck fascia; otherwise, haematoma or urine extravasation is only limited by Colles fascia, giving rise to the butterfly pattern. Digital rectal examination (DRE) can be helpful but may not be appropriate to perform in patients who are not stable or those with severe pelvic fractures as a result of possible pelvic haematoma, which may mask the palpation of a small prostate gland. A high riding prostate may suggest complete urethral disruption, although this is an unreliable sign [20]. Blood on the gloved finger can imply associated rectal injury.

31.2.2.6 Investigation

Retrograde urethrography remains the gold standard for evaluation of urethral injury [21]. In males, the injury is confirmed by the injection of water‐soluble contrast medium up the urethra: a 12‐ or 14‐Fr catheter is inserted 1 cm into the urethra so the balloon is in the fossa navicularis. The balloon is inflated with 1–2 ml of water and 20–30 ml of contrast is injected while the patient is preferably in a 30° oblique position with knee and hip slightly flexed and the urethral meatus occluded. Any extravasation signifies some degree of urethral laceration and permits classification and management of urethral injuries. Whatever its extent, this calls for a suprapubic cystostomy if urethral catheterisation is deemed impossible. In females, urethroscopy complements initial physical examination because urethrography is not possible due to the short urethra.

Ultrasound can be useful in placing the suprapubic catheter. MRI and computed tomography (CT) are not part of the initial assessment of urethral injury, but they are useful adjuncts to evaluate other abdominal and pelvic injuries in addition to assessment of the anatomy of the penile crura and urethra [22, 23].

31.2.2.7 Management

As previously mentioned, urethral injury can easily be confirmed by retrograde urethrography. If there is any extravasation, one must assume that the urethra has been lacerated and a catheter (usually suprapubic) is placed at once. If the diagnosis is delayed, the patient will have passed urine into the soft tissues of the scrotum (Figure 31.9), and unless this is drained, the combination of hypertonic urine and infection will lead to tissue necrosis, which will in turn lead to necrosis of the overlying skin.

Diagram of the male genitalia with lines indicating the perineal body- where Colles fascia is bound down and (Scarpa fascia). — **Figure 31.9** To prevent sloughing both fascial compartments of the scrotum must be drained.

Definitive management of the urethral injury will depend on the circumstances of the injury, whether it is blunt or penetrating, complete or partial, and associated injuries. In blunt posterior urethral injuries (urethral distraction defects), urethral reconstruction is usually deferred for three to six months with urine diverted by means of a suprapubic catheter in the interim. Immediate primary open repair of posterior urethral injury is indicated in patients who are stable with penetrating wounds or with blunt and complete urethral rupture associated with bladder neck or rectal injuries [8] (Figure 31.10). Similarly, patients who are stable with anterior urethral injuries are managed with primary open repair over a urethral catheter if associated with penile fracture or penetrating wounds. It is important to document preoperative erectile function for medico‐legal reasons.

3 Diagrams of male urethra with forcep holding the urethra having severed membraneous urethra (top left); fibrous tissue with tip of bougie passed through suprapubic cystotomy (top right); and retracted tissue with lines indicating external sphincter, verumontanum, etc. (bottom). — **Figure 31.10** If the urethral lumen is completely blocked, the bulbar urethra is explored and anastomosed directly to the torn prostatic urethra.

Many patients with pelvic fractures have other more serious injuries, which take priority. In complete urethral injuries associated with pelvic fractures, if the prostatic urethra heals just behind the bulbar urethra, the lumen of the urethra will form an S‐shaped deformity, leaving two shelves, which may need to be incised with a urethrotome (Figures 31.11 and 31.12). Occasionally, it helps to introduce the flexible cystoscope through the cystostomy track and use its light as a guide for the incision of the obstructing shelves or as a means of introducing a guidewire for subsequent dilatation [24]. Early endoscopic realignment (within two to three days) of urethral distraction injuries is possible but has a high failure rate [25] when compared with the 90% success rate of posterior urethroplasty [25].

2 Diagrams displaying the backward displacement of symphysis indicated by arrow (left) and S-shaped deformity or urethra (right). — **Figure 31.11** The symphysis springs back but not quite completely and the prostate comes to lie just behind its original position.

2 Diagrams illustrating the urethra taking an S‐shaped bend with the diagram on the left having a line indicating light from cystoscope shining through walls of urethra. — **Figure 31.12** The urethra takes an S‐shaped bend whose two leaves can be incised with the urethrotome. It may help to introduce a cystoscope from above and cut down on the light.

Patients with perineal wounds always have many other injuries, and although some of these may take priority, it is urgent that the perineal wound is thoroughly debrided and the urinary and faecal streams are diverted to avoid gas gangrene, which is a common complication and leads to loss of soft tissue that could be useful in the subsequent repair. No attempt is made at primary repair [16, 26].

In gunshot injuries, the damage to the urethra is only one part of multiple injuries involving bone, major blood vessels, and bowel. Again, the first priority is adequate debridement with urinary and faecal diversion by means of a suprapubic catheter and loop ileostomy; no attempt should be made at primary repair [26].

In all cases of urethral injury, the patient should be carefully followed up with re‐evaluation after two to three months with urethrogram, MRI, or urethroscopy. If at this stage, a stricture is found, treatment consists of optical urethrotomy or dilatation if the stricture is short and soft; otherwise, urethroplasty can often be performed with excellent results [27, 28].

In children with diagnosed urethral injury, repair is made more difficult by the narrow urethra of the child and the risk of creating a catheter stricture. Immediate primary repair should be avoided because of high complication rates, and there is always a risk that the damage to the bladder neck may be followed by incontinence [29–31].

31.2.3 Iatrogenic

Iatrogenic urethral trauma is the most common form of urethral trauma in modern urology. Causes include transurethral catheterisation, instrumentation as in transurethral resection or holmium laser enoculation of the prostate procedures (TURP/HoLEP), radical prostatectomy, and radiotherapy. Almost a third of strictures are a consequence of incorrect or lengthy catheterisation most of which are bulbar strictures [32]. Urethral catheterisation may result in ischaemic necrosis of the urethra as in a bedsore (Figure 31.13).

Image described by caption and surrounding text. — **Figure 31.13** Ischaemic necrosis caused by the pressure of a catheter leads to a scar which heals by contraction – a catheter stricture.

Urethroscopy in a man catheterised for chronic retention of urine often shows a white ischaemic patch either at the penoscrotal junction or near the external sphincter. These are common sites for ‘postprostatectomy’ strictures, and they are not caused by the prostatectomy but by the pressure necrosis from the catheter [33] (Figure 31.14).

Diagram displaying catheter inserted into the penoscrotal junction and the external sphincter with lines indicating the pressure sore, pressure sore at the penoscrotal angle, secretion dammed up in gland, etc. — **Figure 31.14** Common sites for catheter strictures are at the penoscrotal junction and the external sphincter.

Factors contributing to stricture formation secondary to transurethral surgery include the use of monopolar current, diameter of instrument used, and surgeon’s experience [34, 35]. A clean incision in the urethra made with a urethrotome, and it heals with a linear white scar without stenosis [36] (Figure 31.15).

One important variety of this iatrogenic damage is seen after surgery on the heart or aorta. For a time, a toxic component of the latex rubber or plastic of the catheter was blamed, but it is more likely that the cause is pressure of the catheter, whatever it is made of, on a urethra that has become relatively ischaemic during aortic obstruction or cardiac standstill. These ‘catheter strictures’ may involve the whole length of the urethra and can be difficult to treat (Figure 31.16) [37–39]. Silicone catheters and small‐diameter catheters seem to minimise the probability of urethral upset [40].

Management of iatrogenic urethral trauma starts with primary prevention of urethral injury during catheterisation or instrumentation. The majority of patients with a suspected urethral stricture following traumatic catheterisation present with pain and urethral bleeding, and they may be difficult to catheterise, which can be due to the stricture itself or false passages.

In cases of difficult catheterisation, retrograde urethrography, or flexible urethroscopy may be helpful in establishing the obstructing anatomical lesion, whether it is a stricture or a false passage. In acute cases, endoscopic placement of a catheter with the aid of a guidewire is recommended [8, 41]. Optical urethrotomy is warranted if a short urethral stricture is encountered, with urethral reconstruction considered for patients who develop a recurrent stricture. Suprapubic catheter placement may be necessary to temporarily drain the bladder [8]. Patients with anastomotic strictures following prostatectomy will require bladder neck incision or dilatation. Treatment of complex urethral strictures precipitated by radiotherapy to the prostate may be difficult to treat and urethral reconstruction may be required [42].