Key points

Introduction

External genital trauma is uncommon but can cause devastating long-term physical, psychological, and functional quality-of-life consequences. Therefore, the treating physician must be able to diagnose the injury in a timely fashion and be knowledgeable of principles of delayed reconstruction. In the civilian population, genital trauma is roughly 45% penetrating, 45% blunt, and 10% burns and industrial accidents. The most important objective of management is preserving genital function and cosmesis, while minimizing long-term sequelae.

Introduction

External genital trauma is uncommon but can cause devastating long-term physical, psychological, and functional quality-of-life consequences. Therefore, the treating physician must be able to diagnose the injury in a timely fashion and be knowledgeable of principles of delayed reconstruction. In the civilian population, genital trauma is roughly 45% penetrating, 45% blunt, and 10% burns and industrial accidents. The most important objective of management is preserving genital function and cosmesis, while minimizing long-term sequelae.

Genital and perineal burns

Burns of the genitalia and perineum require referral to a burn center, are rarely isolated, and typically involve other areas of the body. The genitalia alone only comprise 1% of total body surface area (TBSA), and studies have demonstrated an average TBSA of 21% to 56% for all patients with perineal burns. Initial management of perineal burns is removal of all clothing, rapid and aggressive fluid and electrolyte replacement, and Foley or suprapubic tube placement to monitor sufficient urine output. Evaluation includes a complete physical examination, laboratory evaluation with urinalysis, tetanus prophylaxis, intravenous antibiotics, and an estimate of extent and depth of the burn (TBSA) involved. Burns should be treated according to the mechanism of injury and depth of injury. Genital burns demand very close observation and admission to an intensive care unit or burn unit.

Burn classification/depth of burn

First-degree burns affect the epidermis only and are characterized by pink color, with minimal histologic damage, but significant pain. First-degree burns usually do not have long-term scarring. Second-degree burns are divided into superficial partial thickness and deep partial thickness. Superficial partial-thickness burns involve the epidermis and the papillary dermis and present as pink, moist, tender skin with thin-walled blisters. Deep partial-thickness burns include the reticular dermis and present with mottled red and blanched white skin with thick-walled blisters and tender skin. Third-degree burns are full-thickness burns that destroy the epidermis and the entirety of the dermis. Third-degree burns are characterized by a waxy-white or black, dry skin that is insensate.

Thermal burns

Thermal burns of the genitals are caused mainly by flame, but also by boiling water or grease (with scald). Genital burns are typically first-degree and second-degree burns that can be treated without debridement and require only a topical antimicrobial ointment, usually 1% silver sulfadiazine. Genital third-degree burns should be treated with prompt surgical intervention, as conservative management only leads to increased incidence of infection, longer recovery time and hospital stays, and burn scar contracture.

Third-degree burns to the scrotum should be promptly débrided of all nonviable tissue and then immediately skin grafted. With immediate treatment, infection is usually not an issue and there is no reason for delay in scrotal reconstruction with thigh pouch creation.

The penile skin is very thin and thus vulnerable to full-thickness, third-degree burns. Should this occur, the nonviable skin should be sharply débrided; the wound should be primarily closed, and skin should be grafted to the denuded site ( Fig. 1 ). For circumferential penile injury, severe lymphatic obstruction and lymphedema can occur, so all skin distal from the injury site to the subcorona should be excised. Owing to the tremendous vascularity, burns to the glans usually do not need debridement unless it is clearly necrotic. Patients with third-degree burns to the glans or the ventral shaft of the penis should have suprapubic tubes rather than Foley catheters. Foley catheters can cause pressure necrosis, resulting in severe hypospadias due to anterior urethral slough, especially when left in a dependent position.

Third-degree genital burn to the penis, scrotum, and inner thigh with meshed split-thickness grafts to cover the denuded area.

Thermal burns have the potential for long-term sequelae by urethral slough, urethral stenosis, and eventually scar contracture at 3 to 6 months postinjury. These wounds are managed with surgical release and skin grafts.

Chemical burns

Chemical burns should be managed with immediate removal of any clothing and aggressive flushing with copious amounts of sterile water. However, do not peel off adherent clothing. Duration of exposure and concentration of the chemical are directly proportional to the extent of the injury. Searching for neutralizing agent is not necessary, as time is of the essence for these patients; most are best served with sterile water irrigation.

Electrical burns

Electrical burns can be devastating, as the degree and the depth of the burn can be deceiving. The damage is often beyond what is obviously visible on the surface and an extensive exploration of the deep and surrounding structures are warranted to evaluate the extent of the injury. A thorough workup for electrical burns include examination for any related bladder, rectum, pelvic organ, or skeletal damage by cystoscopy, sigmoidoscopy, vaginal speculum examination (if applicable), and pelvic radiograph. Urinalysis must be obtained for hemoglobinuria and myoglobinuria, as their presence can cause acute renal damage. When present, management should include aggressive hydration along with urine alkalization. Moreover, as cardiac arrhythmias and arrests have been known to be caused by electrical injuries, cardiac monitoring is also warranted. These burns can be managed in the same manner as a thermal burn, with prompt debridement, primary wound closure, and skin grafting. However, these burns are unique in needing additional debridement, often because of the extended damage. With serial debridements, these wounds can be eventually covered with skin grafts, without additional complications. At times, the debridement can be extensive, and bone or major vasculature is exposed in the wound. Myocutaneous flaps for coverage may be necessary at that point.

Animal and human bites

Animal bites to the external genitalia are rare. Dog bites are the most common cause of injury and children are the most common victims. Initial management should include copious irrigation with saline and providone-iodine solution, debridement, broad spectrum antibiotic prophylaxis, tetnus-rabies immunizations (when appropriate), and immediate/early closure of wound. Infections after dog bites are rare, but treatment is sought soon after the event. Recommended antibiotic therapies include β-lactam antibiotics with β-lactamase inhibitor (eg, amoxicillin-clavulanate), second-generation cephalosporins (eg, cefotetan, cefoxitin), or clindamycin with fluoroquinolones.

Most human bite victims seek medical care after substantial delay and are more likely to present with gross infection of their wound than with a dog bite. Human bites are contaminated wounds that should never be closed primarily. Empiric antibiotic therapy of choice includes amoxicillin-clavulanate or moxifloxacin.

Scrotal degloving injuries

Due to the pendulous nature of the male genitalia and the laxity of the covering skin, the scrotum has tremendous capacity to resist injury. The skin, however, remains vulnerable to degloving injuries ( Fig. 2 ). In the past, most degloving injuries were caused by agricultural (“power takeoff”) and manufacturing machinery, but the incidence has decreased considerably with improved safety measures. Most present-day genital skin avulsion is due to motorcycle or bicycle accidents.

Extensive scrotal skin loss following a degloving injury.

Avulsion injuries are usually along the fascial planes, often torn free without damage to the underlying tunica vaginalis or dartos fascia. The scrotal skin is very compliant, redundant, and elastic and so defects with up to even 60% skin loss can be primarily closed. To help prevent scrotal bleeding/hematoma after injury, a 2-layered closure of the deep fascia and skin is performed with an interlocking, running, absorbable suture. A scrotal drain after repair is controversial because resultant scrotal hematomas are usually in the interstitium of the skin and are not hematoceles. However, if hemostasis is not possible or the patient has a coagulopathy, either a Penrose drain or a closed suction drain (eg, a Blake drain) is recommended. An antibacterial gauze dressing, such as xeroform, with fluff gauze and a compressive scrotal support should be placed to promote comfort and to facilitate healing.

If blunt traumatic scrotal skin loss is extensive (greater than 60%), several options are available for coverage. Repair should be performed without delay if the injury to the scrotum is not contaminated. Local skin flaps are all preferred options for coverage. When additional coverage is needed, split thickness skin grafting is the repair of choice, because it yields excellent cosmetic and functional outcome ( Fig. 3 ). Other ancillary measures include autologous skin grafts and tissue expanders. To begin the procedure, the testicles and cords are sutured together in the midline with multiple 3-0 polyglactin (Vicryl; Ethicon, Somerville, NJ, USA) sutures to create a singular structure, to ease skin grafting. The thick split-thickness skin graft is then harvested with a dermatome at 15 to 18 thousandths of an inch, ideally from the inner thigh, and meshed 1.5:1. Skin grafts to the penis are typically performed with nonmeshed grafts for both cosmesis and erectile function. For the scrotum, meshed grafts are used as the meshing simulates rugae, while allowing exudates to escape, thus improving graft take. The graft is then applied to cover the testes and cords and sutured in place at the perineum and ventral penile base. Multiple interrupted chromic sutures are placed in the graft to “quilt” it to the underlying tissue. The “neoscrotum” is then covered with xeroform, mineral oil–soaked cotton batting, and fluff gauze bandage. Bolster sutures of purple-dyed 2-0 Vicryl are then placed at the graft margins and tied over the dressings to facilitate immobilization. An easier-to-apply and quicker alternative to a bolster dressing is the use of a negative pressure wound therapy device (refer to section Management of Complex Urologic Wounds). Postoperatively, the patient is typically kept on bed rest for 48 hours (to prevent graft movement and allow for maximal imbibitions) and the dressings are removed on postoperative day 5. The patient then showers twice a day with soap and water, using a blow dryer on cool or gently patting the graft or harvest site with a towel to dry the graft.

Meshed split-thickness skin graft to cover the scrotum.

If the circumstances of the injury prevent immediate repair of the scrotum, the testicle should be wrapped in saline-soaked gauze for protection until surgery. If definitive reconstruction is going to be delayed or the genital and perineal skin defects are very large, the testicles may be protected in superficial thigh pouches as long as necessary ( Figs. 4 and 5 ). Thigh pouches not only protect the testes but augment future scrotal reconstruction, reduce the size of the perineal skin defect via secondary intention closure, and lighten the burden of labor-intensive and dressing changes that are often very painful to the patient. Thigh pouches prevent the testes and cord from forming a thick, fibrous, infected rind of granulation tissue. Should this “rind” of granulation tissue form, it must be completely removed down to the spermatic fascia and tunica for skin graft to take. The rind is chronically infected tissue and is a poor bed for skin graft to take. If the rind is left in situ, the neoscrotum becomes contracted and flattened out into an abnormal, nondependent position. Care must be taken to avoid transmission of the infection to the thigh region, so gross contamination must be eliminated beforehand.

Extensive penile and scrotal skin loss following a degloving injury.

Creation of testicular thigh pouch following scrotal avulsion injury.

To create thigh pouches, the testis and cord are initially dissected to the level of the external ring. To prevent stretching of the spermatic cord with thigh abduction, subcutaneous tissue pockets in the fascia of the thighs should be dissected as far posteriorly and caudally as possible to allow for slack in the cord. Next, the fascia lata of the thigh is identified and then the pouch is dissected superficial to the fascia lata with a sponge stick and 2 narrow deavers into the anterior thigh. If the testes are placed too medially, it may cause pain and discomfort when patients adduct their legs. The plane usually dissects out easily and bluntly. Placing the testes and cord directly on top of the fascia lata facilitates mobilization for delayed scrotal reconstruction.

Penile degloving injuries

Penile degloving injuries typically require immediate reconstruction and should be treated with a sense of urgency owing to the nature of their function. Similar to the repair of the scrotum, primary closure of the skin should be attempted. Primary closure of the penis is often difficult, because the shaft skin is not as elastic or as redundant as scrotal skin. Not infrequently, the penile skin defect is circumferential, disrupting distal lymphatic drainage. With circumferential avulsion, the remaining skin distally must be excised to the subcorona to prevent chronic, disfiguring lymphedema.

The primary objective of reconstruction is to preserve erectile function. If a primary closure is not feasible, a thick nonmeshed split-thickness skin graft should be placed because it is less likely to contract ( Fig. 6 ). Meshed split-thickness skin grafts on the penis can occasionally contract to the extent that erections become impaired. The skin graft should be wrapped around the penis with the seam on the ventral aspect of the shaft, to simulate a median raphé, while avoiding chordee. (Skin grafts placed on the penis shaft never regain normal sensation. However, sexual function is often preserved due the intact sensation in the glans. ) The graft is temporarily held in place with staples, and then quilting sutures (interrupted 3-0 chromic suture) are placed. At the proximal and distal aspect of the penis, 4 sutures of long, purple-dyed 2-0 Vicryl are placed circumferentially to tie over a bolster dressing.

( A ) A thick nonmeshed split-thickness skin graft around the shaft of the penis. ( B ) Two months postoperative following penile skin grafting.

The layers of dressing placed on top of the skin graft around the penis are Xeroform gauze, followed by a layer of mineral oil–soaked cotton wadding, fluff gauze, and then a compressive wrap of elastic bandage (conform). The long, purple-dyed stay sutures are then tied down to hold this bolster fixed in place ( Fig. 7 ). Postoperatively, the patient is kept at bed rest for 48 hours, and the dressing removed at approximately postoperative day 5. These instructions are then followed by twice-daily showers and gentle drying of the graft with the cool setting of a hair dryer. An alternative, simpler way to immobilize the skin graft is to wrap the fluff dressing with elastic bandage (conform) and staple the conform periodically while wrapping it around the penis, leaving the glans exposed. The final tight dressing is stapled at the edges of the skin.

“Penis-house” following skin grafting of penis.

If the patient is impotent and elderly, a meshed split-thickness skin graft is acceptable. In addition, a scrotal flap (modified Cecil technique) can be used to cover the denuded penis, as long as the patient does not mind a hair-bearing penis and is impotent. ¹² To create the scrotal flap, a transverse incision is made in the inferior aspect of the scrotum followed by the formation of a subdartos tunnel. The penis is then mobilized through the tunnel, leaving only the glans exposed, while covering the denuded penile shaft. The scrotal flap edge is then sutured to the subcoronal skin with interrupted absorbable sutures. Patients have the option to undergo a second-stage repair to free the penis, which few select.