Brad Figler, MD
Bryan Voelzke, MD, MS
BASICS
DESCRIPTION
• Necrotizing soft tissue infection arising in the genitalia and/or perineum
• Rapidly progressive and life-threatening with a high mortality rate
• Much more common in men than women
ALERT
Fournier gangrene is a urologic emergency, causing progressive tissue destruction with significant potential for soft tissue loss, sepic shock, and death. Prompt debridement is mandatory.
EPIDEMIOLOGY
Incidence
• 1.1 per 100,000 patients are admitted for treatment of Fournier gangrene nationally (1)
• Most common in 5th and 6th decades of life
• Male > Female (10:1)
• Limited to 60 case reports in children
Prevalence
Unknown
RISK FACTORS
• Alcoholism
• Diabetes mellitus
• Genital skin trauma
• Impaired immunity
• IV drug abuse
• Recent penile, perineal, or perirectal surgery
• Urethral stricture
PATHOPHYSIOLOGY
• Primary insult is a breach in the integrity of the GI or urethral mucosal lining
• Infection is frequently polymicrobial (aerobic and anaerobic, gram-positive and gram-negative)
• Pathogens differs from nonnecrotizing infection: Higher frequency of virulent organisms such as group A streptococci, community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), and Clostridium spp (2)
• Obliterative endarteritis leads to thrombosis, ischemia, and necrosis, which allows for further bacterial proliferation
• Process extends along Dartos and Colles fascia, potentially involving perineum, abdomen, thighs, ischiorectal fossa, and retroperitoneum
• Rates of spread as high as 2–3 cm/h have been reported
• Deep structure (corpus cavernosum, corpus spongiosum, and testicles) are typically not affected
ASSOCIATED CONDITIONS
• Perianal/scrotal abscess
• Immunosuppression
• Obesity
• Urethral stricture
• Paraplegia
• Malignancy
• Septic abortions, vulvar abscesses, and episiotomy (in women)
GENERAL PREVENTION
• Early recognition/treatment of infection
• Early and aggressive management of underlying immunosuppressive conditions
DIAGNOSIS
HISTORY
• Presentation is typically abrupt with severe pain in the perineum, abdominal wall and thighs, however a prodrome of several days of fever and lethargy can be seen
• Perineal or genital trauma (including bites)
• Urethral instrumentation
• Perirectal/scrotal/perineal abscess or wound
• Urinary tract infection or STD
• Urethral stricture disease
• Anal fissure, fistulae, or hemorrhoids
• Alcohol or IV drug abuse
• Malignancy
• Diabetes mellitus
• Steroid use
• HIV
PHYSICAL EXAM
• Altered mental status
• Pain out of proportion with physical exam
• Tachycardia and tachypnea
• Fever or hypothermia
• Cellulitis
• Dusky, erythematous or frankly necrotic, skin
• Foul odor described as strong or feculent
• Crepitus
• Edema of the involved skin
• Purulent drainage
• Rectal exam essential. Assess for:
– Tumor
– Perirectal abscess
DIAGNOSTIC TESTS & INTERPRETATION
Lab
• CBC: Leukocytosis/leukopenia, anemia
• Serum chemistry: Hyponatremia, hypocalcemia, elevated serum creatinine, hyperglycemia, metabolic acidosis
• Myonecrosis may elevate CK levels
• Coagulopathy
• Glucosuria and pyuria
• Wound culture (aerobes, anaerobes, fungi)
– Aspiration of subcutaneous skin at the point of demarcation for Gram stain and culture may be useful
– Deep tissue cultures at the time of surgery should be obtained
• Urine and blood culture. In spite of severe clinical findings blood cultures are rarely positive
Imaging
• Plain radiography or ultrasound may show subcutaneous emphysema; less sensitive than CT
• CT helpful in identifying nidus of infection and/or subcutaneous emphysema
• MRI can be used to define affected areas, but should not delay prompt surgical intervention
Diagnostic Procedures/Surgery
• Immediate surgical debridement
• Incision should be extended until normal appearing tissue is encountered
• Infection presumed present as far peripherally as swelling, erythema exist, watery pus, or necrotic fascia are found
Pathologic Findings
• Intact epidermis with dermal necrosis
• Vascular thrombosis
• Acute PMN infiltrate
DIFFERENTIAL DIAGNOSIS
• Cellulitis
• Balanitis
• Epididymitis/orchitis
• Hidradenitis suppurativa
• Pyoderma gangrenosum
• Strangulated inguinal hernia
• Testicular torsion
TREATMENT
GENERAL MEASURES
• Immediate and aggressive surgical therapy with debridement of necrotic tissue
• Aggressive fluid resuscitation (isotonic fluid)
• Inotropic support is frequently necessary
• Correct coagulopathy
• Quadruple antibiotics
• ICU support until clinically stable
MEDICATION
First Line
• Antibiotics should include gram-positive, gram-negative, and anaerobic coverage in full therapeutic dosages
• Modify antibiotics as needed, based on Gram stain, culture, and sensitivity
• Appropriate empiric therapy typically consists of:
– Penicillin G 3–5 million international units IV q6h (Gram-positive coverage)
– Imipenem 500–1,000 mg IV q6h (polymicrobial coverage)
– Clindamycin 600–1,200 mg/d, divided dose (anaerobic coverage)
– Vancomycin 1 g IV BID (MRSA)
Second Line
• Potential single-agent regimens include:
– Imipenem/cilastatin
– Meropenem
– Ertapenem
– Piperacillin/tazobactam
– Ticarcillin/clavulanic acid
– Tigecycline
• Intravenous immunoglobulin may be a useful adjunct in treatment of staphylococcal or streptococcal infections with signs of toxic shock syndrome (TSS)
SURGERY/OTHER PROCEDURES
• Immediate and aggressive wide surgical debridement and irrigation with bacteriocidal solution minimizes progression of necrosis.
• All affected tissues should be debrided; questionable involvement can be treated with incision and drainage and observation.
• Repeat exam under anesthesia and possible debridement at 24-48 hr
• Fascia and muscle are rarely involved and do not typically require wide resection.
• Testicles and tunica vaginalis are rarely involved; when possible, tunica vaginalis should be left intact to facilitate future application of skin graft
• Consider cystoscopy if there is concern for urethral nidus
• Consider proximal urinary diversion (suprapubic tube, percutaneous nephrostomies) if the penis is extensively involved
• If perirectal disease is identified, exam with proctoscopy under anesthesia is necessary
• Postoperative care
– If a vacuum assist closure (VAC) dressing is not used, wet-to-dry dressing changes are performed BID-TID
– EUA after 24–48 hr to assess for and debride newly necrotic tissue
– Follow cultures for sensitivities and adjust antibiotic therapy accordingly
– Nutritional support (preferably enteral) should be instituted early to correct the negative nitrogen balance associated with profound sepsis
ADDITIONAL TREATMENT
• VAC may result in earlier wound granulation compared to simple wet-to-dry dressing changes, but may be difficult to apply to the perineum and genitalia (Level I) (4)
• If a VAC closure is not possible, the wound should be packed with fine-mesh gauze soaked in normal saline, Dakin (25%) solution, or Clorpactin
• Diverting colostomy may help keep perineal or peri-anal wounds clean
• Reconstruction can be performed after the patient has stabilized and the wound demonstrates adequate granulation
• When health of graft bed is uncertain, xenograft is an inexpensive and useful method for temporary wound coverage and is helpful in assessing suitability of graft bed for autologous skin grafting. Xenograft should be removed within 2 wk
• If <50% of scrotum is resected, can be reconstructed primarily
• Split-thickness skin grafts (meshed or unmeshed for penis; meshed for scrotum) are useful for covering small or extensive wounds, with excellent long-term results (4)
• Thigh pouches for testicles are effective, but can cause pain and interfere with testicular exam
Complementary & Alternative Therapies
• Whirlpool therapy for micro-debridement
• Hyperbaric oxygen may be helpful if used early as an adjunct to radical debridement (3)
• Dakin’s solution, Sulfamylon solution, or Silvadene cream can be applied during each dressing change
ONGOING CARE
PROGNOSIS
• Historically, Fournier gangrene carried a >50% mortality rate
• Modern mortality rates average 5–20%, which is highly dependent on prompt diagnosis and tight coordination of definitive care (1)
COMPLICATIONS
• Coagulopathy
• Death from sepsis
• Disfiguring skin and soft tissue loss
• Infertility
• Multi system organ failure
• Renal failure
• Urethral stricture
FOLLOW-UP
Patient Monitoring
Prolonged critical care may be required.
Patient Resources
http://www.mayoclinic.com/health/gangrene/DS00993
REFERENCES
1. Sorensen MD, Broghammer JA, Rivara FP, et al. Fournier’s gangrene: Contemporary population-based incidence and outcomes analysis: A HCUP database study. J Urol. 2008;179(4):13.
2. May AK, Stafford RE, Bulger EM, et al. Treatment of complicated skin and soft tissue infections. Surg Infect (Larchmt). 2009;10(5):467–499.
3. Mindrup SR, Kealey GP, Fallon B. Hyperbaric oxygen for the treatment of Fournier’s gangrene. J Urol. 2005;173:1975–1977.
4. Black PC, Friedrich JB, Engrav LH, et al. Meshed unexpanded split-thickness skin rafting for reconstruction of penile skin loss. J Urol. 2004;172(3):976–969.
ADDITIONAL READING
Vick R, Carson CC, 3rd. Fournier disease. Urol Clin North Am, 1999;26(4):841–849.
See Also (Topic, Algorithm, Media)
• Diabetes Mellitus, Urologic Considerations
• Urosepsis (Septic Shock)
• Fournier Gangrene Images 
CODES
ICD9
• 608.83 Vascular disorders of male genital organs
• 616.89 Other inflammatory disease of cervix, vagina and vulva
ICD10
• N49.3 Fournier gangrene
• N76.89 Other specified inflammation of vagina and vulva
CLINICAL/SURGICAL PEARLS
• Signs of local infection with pain out of proportion to physical exam is highly suspicious for a diagnosis of Fournier Gangrene.
• Prompt and radical debridement is mandatory.
• Infections are typically polymicrobial, so broad-spectrum antibiotics are critical.