Principles of burn reconstruction: Perineum and genitalia

INTRODUCTION — Burns to the perineum and genitalia are an uncommon, but devastating, injury [1]. Burns to these areas generally occur in conjunction with burns involving other anatomic sites, but may be isolated, as in the cases of intentional scalding [2,3]. Resuscitation and stabilization of the burned patient are the first priorities, followed by management of the burn wounds.

Burns to the perineum and genitalia can potentially impair or destroy function, aesthetics, and the ability to maintain proper hygiene. The loss of normal tissue and scarring can limit movement, and cause pain, disfigurement, and social embarrassment. Surveillance for preservation of genitourinary and sexual function is a component of the treatment plan.

The initial management of burns to the perineum and genitalia and reconstruction of the resultant complicated wounds are reviewed. Acute assessment and management, general treatment of superficial and deep burn injury, and an overview of burn reconstruction are provided separately. (See "Overview of the management of the severely burned patient" and "Assessment and classification of burn injury" and "Emergency care of moderate and severe thermal burns in adults" and "Treatment of superficial burns requiring hospital admission" and "Treatment of deep burns" and "Overview of surgical procedures used in the management of burn injuries".)

EPIDEMIOLOGY AND ETIOLOGY — Burns to the perineum and genitalia occur in approximately 3 to 13 percent of all patients sustaining burns [4,5].

The most common causes of perineal and genital burns include scald, flame, chemical, and electrical contact [2-4,6]. Isolated burns to the perineum and/or genitalia are rare, particularly in females, and in children are a marker of abuse and warrant further evaluation [1,4,6-8]. (See "Physical child abuse: Recognition", section on 'Intentional burns' and "Physical child abuse: Diagnostic evaluation and management" and "Child abuse: Social and medicolegal issues".)

Accidental burns can sometimes be distinguished from intentional burns. Intentional scalds are symmetrical, have distinct upper borders and may be associated with old fractures or unrelated injuries. By comparison, unintentional perineal burns have irregular borders and depth.

INITIAL MANAGEMENT — The initial management of patients with superficial and deep burns to the perineum and genitalia prior to any potential surgical management is conservative, including cleansing, gentle gauze debridement of loose burned tissue if present, and coverage with topical antimicrobial agents and dressings. The wound healing rate with conservative measures ranges from approximately 80 to 96 percent [1,4,6,7]. (See "Topical agents and dressings for local burn wound care".)

For patients with substantial burns involving the perineum and/or genitalia alone, or including the inguinal or lower truncal areas, the management is more complex. The thighs should be maintained at 15° abduction to facilitate healing and dressing changes [1]. In addition to local topical agents and dressings, the initial management of the extensively burned patient also includes protecting the urethral meatus from obliteration due to swelling and protecting the burned skin from urinary and fecal contamination.

Necrotizing infections can occur in contaminated perineal burn wounds. The treatment of necrotizing cellulitis and fasciitis is discussed separately. (See "Necrotizing soft tissue infections" and "Surgical management of necrotizing soft tissue infections".)

Urinary management — In large surface area burns requiring fluid resuscitation, a urethral catheter is generally placed in the acute setting to monitor urine output, control urinary continence, and avoid the risk of inability to catheterize the urethra [1]. A delay in urethral catheterizing can result in an inability to see the meatus as edema develops in the preputial skin in males and labial tissue in females.

However, care should be taken in the younger male child, as catheterization can lead to stricture formation. A urinary catheter can also act as a conduit for bacterial contamination and infection. Thus, even in burns to the perineum and genitalia, the use of urinary catheterization should be considered with some caution. (See "Placement and management of urinary bladder catheters in adults".)

Bowel management — Fecal contamination of a burn can result in sepsis, delayed wound healing, graft loss, and contracture of scars [9]. Fecal diversion can be managed with a bowel management system (rectal tube) or a diverting colostomy [9-13]. If a colostomy is used, the stoma can be reversed after the burns have healed. (See "Overview of surgical ostomy for fecal diversion".)

For most patients, a rectal tube is adequate; however, these tubes function properly only if the stool is loose. Stool softeners and enemas are used to maintain loose stools to prevent obstruction fecal impaction. Two specifically designed intrarectal catheters (eg, Zassi Bowel Management System and the Flexi-Seal Fecal Management System) are safe and effective in managing fecal diversion without skin graft loss or a colostomy, but they can cause anal ulceration and sphincter atony [9,10,13].

Temporary diverting colostomy has been advocated for deep perineal burns and in young children [12]; however, with modern bowel management systems, most burn clinicians have found this to be unnecessary [14]. In adults, a diverting colostomy facilitates perineal burn wound management, and may be necessary early in the acute debridement phase. However, complications in the acute period may be encountered including peristomal bowel herniation, difficulties sealing the stoma in the presence of the surrounding burn with leakage of bowel contents, maceration of the peristomal skin, and devitalized bowel in the stoma area. Under these circumstances, routine care can be challenging. (See "Ileostomy or colostomy care and complications".)

Debridement and demarcation — It may be difficult to initially determine the burn wound depth and as such, to preserve skin and function of the genitalia, the burn wound may need to be allowed to demarcate. Demarcation is the conversion of an apparently superficial wound depth to a deeper burn depth, typically occurs by the third post-burn day [15,16]. (See "Assessment and classification of burn injury", section on 'Classification by depth'.)

Acute coverage of deep burns, and superficial burns that do not heal with conservative management, includes sharp debridement of the burn eschar after demarcation and coverage of the site with skin grafts. (See "Overview of surgical procedures used in the management of burn injuries".)

RECONSTRUCTION — Reconstruction of the burn wound serves to restore function and improve aesthetics by releasing or excising scar contractures and/or remodeling tissues. (See "Overview of surgical procedures used in the management of burn injuries", section on 'Coverage of soft tissue defects and deep structures'.)

Laser techniques — A useful approach to the management of abnormal scarring is the use of laser techniques such as ablative and nonablative fractional CO2 techniques and pulsed dye laser techniques, to name a few [17,18]. Its use has shown to improve both appearance and function and to reduce the use of more aggressive standard operative standard techniques. We usually give patients three to five treatments separated by six to eight weeks in any obvious perineal contracture prior to potential surgery.

Reconstruction is typically performed after scar maturation (unless deterioration and loss of function appear earlier), which can require at least one year to develop after wounds have healed. In some instances, reconstructive procedures are performed sooner, such as stricture formation involving the urethra or perineal scar obstructing the anus. (See "Overview of surgical procedures used in the management of burn injuries", section on 'Burn scar revision and timing'.)

Perineum — Cicatricial contractures are the most common complication of perineal burns, occurring in approximately one-third of patients with partial- or full-thickness perineal and genital burns [7,19]. The perineal contracture can present as a scar band that extends between the medial thighs and crosses the area between the genitalia and the anus, or as a band that extends between the proximal medial thigh to the perineum [19,20]. These scars can result in perineal obliteration, hip adduction contractures, and limitation of the hip range of motion [20,21].

The reconstructive procedure performed depends upon the extensiveness of the scar and availability of unburned tissue for coverage of the defect created by contracture release or scar excision. There is no one optimal approach, and the surgeon must make a case-by-case decision for each patient.

●For patients with a limited burn contracture, an excision of the contracture with primary closure of the defect can be performed [7].

●For patients with moderate contractures, or those for whom a primary wound closure is not possible, the defects can be managed using local trapezoid flaps created from tissues on the inner thighs [20]. These flaps are variations of the transposition Z-plasty technique that uses adipocutaneous flaps from neighboring skin to interrupt or realign scars without using a skin graft. When performing this technique using burned skin, caution is advised when mobilizing flaps to avoid flap loss. (See "Z-plasty".)

●An alternative to trapezoid flaps for wound coverage is the perforator flap [22]. The perineum has a rich blood supply with multiple perforating vessels supplied by the vessels of the lower abdomen, medial thigh, and gluteal region. Knowledge of the perineal blood supply can be used to plan a variety of perforator flaps that can be used in perineal burn reconstruction.

●For wounds not amenable to primary closure or closure with local trapezoid flaps, the defects created by the contracture excision can be covered with full-thickness skin grafts, or partial-thickness skin grafts with a dermal regeneration template [19]. A discussion on the advantages and disadvantages of the types of skin grafts is reviewed separately. (See "Skin autografting" and "Skin substitutes".)

●For extensive defects that result from excision of large scars, fasciocutaneous flaps can be used. The groin flap, a fasciocutaneous flap that includes the fascia from the sartorius muscle, is excellent tissue for simultaneous perineal, inguinal, and anal reconstruction [23]. The anterolateral thigh flap, which is located between the rectus femoris and vastus lateralis, has emerged as one of the most versatile reconstructive options for multiple sites. Based on a perforator flap harvest concept, the flap encompasses the advantages of versatility, pliability, and potential for composite tissue replacement [24].

Genitalia — The use of skin grafts with or without dermal scaffolding material is the most frequent procedure performed for secondary reconstruction of burned genitalia. Other options include fasciocutaneous flaps and variations of the Z-plasty technique [25-27]. The local flap options described for secondary contractures in the inguinal region also apply to reconstruction of genitalia. (See "Principles of burn reconstruction: Extremities and regional nodal basins", section on 'Inguinal region'.)

Ingenious methods of splinting to secure the skin graft or flap in place have been created. We use Allevyn foam [28] for its ease of application and have also used topical negative pressure [29]. (See "Negative pressure wound therapy".)

Male — Burns to the male genitalia may cause tissue retraction and scarring, which can result in shaft deformity, inability to achieve normal erections, and meatal obstruction. The goal of reconstruction of the penis and scrotum is to maintain urinary and sexual function and preserve anatomical and aesthetic integrity.

The medical and functional consequences of a burn involving the male external genitalia depend upon the depth and extent of the burn injury. For deep and/or unhealed burns, sharp debridement of devitalized burned tissue is typically performed. Prior to initiating sharp debridement, the urethra should be protected by inserting an indwelling urinary catheter. The penis should be held under gentle traction and all burned tissue sharply debrided. We use a Goulian knife with an 8/1000 inch guard; a hydrosurgical technique with the VersaJet system is an acceptable alternative [30].

Following sharp debridement of devitalized tissue, reconstruction of the male genitalia can proceed depending on the site involved, extensiveness of the burn, and the availability of unburned skin. The following reconstructive options are available:

●The scrotum can usually be reconstructed using full-thickness skin grafts alone or split-thickness skin grafts with a dermal template.

●If the testicles are exposed as a result of the burn or debridement, they can be transferred to pockets fashioned in the inner thigh. While testicular function is preserved, the cosmetic appearance is relatively poor.

●Reconstruction of the penis involves release of the burn contracture to prevent foreshortening of the shaft.

•If Buck's fascia is spared (figure 1), multiple Z-plasties can be performed to release the contracture. If the contracture is excised, the defect created is covered with a full-thickness skin graft. Split-thickness skin graft alone may result in debilitating, inelastic, and painful hypertrophic scars [31]. If using split-thickness grafts, a dermal template should be used to avoid these complications.

If Buck's fascia is involved, a surgical release of the deformity is performed, and the defect can be covered with a pedicled flap, such as the anterolateral thigh flap [26] or the medial circumflex femoral artery perforator flap [27].

•Patients with loss of the deeper layers of the penis, such as the corpora cavernosa, or loss of the glans and meatus, require a complex and multidisciplinary approach with urologic expertise. Prosthetics and complex free microvascular flaps to reconstruct a neo-phallus may be necessary, such as a thoracodorsal artery perforator flap [32] or a forearm fasciocutaneous flap [33] and full-thickness skin grafts to create a urethral tract [34].

•Scarring of the prepuce is treated by circumcision [4]. Skin from the circumcision can be used as a full-thickness graft to the penile shaft if needed.

•Complete loss of a penis following a burn is rare, and there are few reports available that address reconstruction. The microvascular free tissue transfer of a composite radial forearm fasciocutaneous flap phalloplasty with or without a prosthesis or bone graft is an option to closure and urinary drainage through a large meatotomy [25,35]. A phalloplasty is a challenging procedure associated with complications that include an urethrocutaneous fistula and hair formation [35]. If a total loss occurs in a child, reconstruction is typically performed at age 6 to 8 years, even though revisions will be necessary as the child reaches puberty, because of the psychologic impact that can affect the child and family [35].

Female — The approach to reconstruction of female genitalia after a burn is based upon case reports and small series of patients [8,36]. Release of contractures with Z-plasty approach and reconstruction with skin grafts and regional flaps are the most common reconstructive procedures used.

The reconstruction of the external genitalia and of the internal vault represents similar challenges to the ones described for male genitalia. The reconstructive options available include [1]:

●The vaginal vault is usually reconstructed with regional flaps such as the rectus abdominis, gracilis, or perforator based flaps. (See "Vaginectomy", section on 'Vaginal reconstruction'.)

●Distortion or destruction of the labia is corrected by release or excision of contractures and reconstruction using local skin flaps or grafts [1,8].

•To restore a contour deformity caused by loss of skin and subcutaneous tissue, reconstruction can be performed by using an adjacent skin flap and lipoinjection. An alternative is a local flap based in the pudendal artery axis that provides a more pliable though slightly bulkier form of reconstruction.

•The defect created by contracture release can be covered with a full-thickness skin graft or a split-thickness skin graft and dermal regeneration template. The type of graft used depends upon the availability of unburned skin.

Outcomes — There is limited information on the outcomes of reconstructive procedures for burns to the perineum and genitalia, at least in part due to the rarity of the burn. A review of 5280 pediatric burn reconstructive procedures identified only 18 children (less than 1 percent) undergoing a release of a perineal contracture [19]. The initial management of 14 of the 18 patients was conservative with minimal wound debridement, topical antimicrobials, and dressing changes. The other four patients were treated with excision and skin grafts.

The mean time from burn to contracture development was 3.8 years (range 3 months to 11 years). The contractures were treated with a local flap (10 patients), incisional release and split-thickness skin grafting (5 patients), primary closure and release (1 patient), and a combination of these procedures (2 patients). A secondary contracture developed in 4 patients between approximately three and five years after the initial perineal reconstruction.

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: Care of the patient with burn injury".)

SUMMARY AND RECOMMENDATIONS — Burns to the perineum and genitalia are uncommon, particularly as isolated events.

●The primary goal of managing burns of the perineum is preservation of urinary and fecal continence. The initial management of burns to the perineum and genitalia include cleansing, gentle gauze debridement of loose burned tissue, topical antimicrobial agents, and dressing changes. Urinary catheters, rectal tubes, and/or a colostomy (temporary or permanent) can be used to protect the burned perineum from contamination. (See 'Initial management' above.)

●Burns should demarcate before attempting sharp debridement. (See 'Initial management' above.)

●Reconstruction of the perineum includes release of scar and coverage with skin grafts alone or with dermal regeneration templates, Z-plasty techniques with local trapezoid flaps, or fasciocutaneous flaps. (See 'Perineum' above.)

●The reconstructive approach is based upon the extensiveness of the scar and the availability of unburned tissue for reconstruction. Reconstruction of the male genitalia is performed to restore function and aesthetics. The scrotum can be reconstructed with skin grafts, and the penis with contracture release and coverage with skin grafts or pedicled flaps, depending on the extensiveness of damage (see 'Male' above). For complete loss of a penis in children, reconstruction is delayed until puberty. Free tissue transfer with or with without the use of a tubed prosthesis may be required in total loss of the penis to warrant sexual function.

●Reconstruction of the female genitalia includes release of contractures with Z-plasty techniques, skin grafts, and regional flaps. Reconstruction of the vaginal vault can be performed with a flap, such as the rectus abdominis or gracilis flap. (See 'Female' above.)