What is Fournier's Gangrene?
Fournier's gangrene is a life-threatening necrotizing fasciitis of the external genitalia, perineum, and perianal region that represents a true surgical emergency with mortality rates of 20-50%. 1
Definition and Disease Characteristics
This is an aggressive, polymicrobial soft-tissue infection involving the scrotum, penis, perineum, and perianal areas that rapidly destroys tissue through a combination of bacterial proliferation and vascular thrombosis 1
The infection is typically polymicrobial, involving both aerobic organisms (Streptococcus species, Staphylococcus species, Escherichia coli) and anaerobic bacteria that work synergistically to cause rapid tissue destruction 2
The pathophysiology begins when commensal bacteria enter the perineum through a portal of entry, triggering inflammatory response and obliterative endarteritis with vessel thrombosis, leading to tissue ischemia that promotes further anaerobic bacterial growth 2
Epidemiology and Risk Factors
Fournier's gangrene predominantly affects males with a male-to-female ratio of 42:1, with a mean age of presentation at 51 years and an overall incidence of approximately 1.6 cases per 100,000 males annually 2
Diabetes mellitus is the single most important risk factor, followed by obesity, immunocompromised states (including HIV, malnutrition, leukemia), chronic alcoholism, and high body mass index 2, 1
Common anatomic sources include perianal/perirectal abscesses (45.8% of cases) and urethral damage, with fecal contamination and anal sphincter involvement serving as additional infection sources 2
Clinical Presentation
The classic presentation includes painful swelling of the scrotum or perineum accompanied by sepsis, though up to 40% of cases have a more insidious onset with undiagnosed pain that dangerously delays treatment 1
Key clinical findings include scrotal or perineal erythema, edema, tenderness, subcutaneous crepitations (gas in tissues), patches of gangrene or necrosis, foul-smelling purulent discharge, and tenderness to palpation 3, 1
A high index of suspicion is essential, particularly in obese patients where physical examination is limited 1
Anatomic Spread Pattern
The infection extends along superficial perineal fascial planes, allowing cranial extension to the abdominal wall and caudal spread to the thighs 2, 1
Testicular involvement is rare due to the separate blood supply from the spermatic vessels 1
Diagnostic Approach
Contrast-enhanced CT scan is the preferred imaging modality with 90% sensitivity and 93.3% specificity for evaluating disease extent and identifying underlying causes, though surgery should never be delayed for imaging in hemodynamically unstable patients or those with clinically obvious findings 3
Laboratory workup should include complete blood count looking for leukocytosis, inflammatory markers (C-reactive protein, procalcitonin), and blood cultures obtained before initiating antibiotics 3
The Fournier's Gangrene Severity Index (FGSI) should be calculated using physiological parameters (temperature, heart rate, respiration rate, sodium, potassium, creatinine, leukocytes, hematocrit, bicarbonate) to predict outcomes 3
Management Principles
Surgery must not be delayed for any reason—immediate aggressive surgical debridement is mandatory, with removal of all necrotic tissue at the initial operation and planned repeat debridement every 12-24 hours until no necrotic tissue remains 3
Start empiric broad-spectrum antibiotics immediately upon suspicion, before surgical intervention, with coverage for gram-positive organisms (including MRSA), gram-negative organisms, and anaerobes 3
Obtain microbiological samples (cultures of infected fluid and tissue) during the index operation to guide subsequent antibiotic de-escalation 3
Avoid orchiectomy or extensive genital surgery unless absolutely necessary, and involve urology, colorectal surgery, and critical care specialists early in the multidisciplinary approach 3
Consider fecal diversion (colostomy) only for anal sphincter involvement, fecal incontinence, or continued fecal contamination, but delay this decision for 48 hours after initial surgery to allow inflammation to subside and permit proper sphincter evaluation 3