Fournier's gangrene complicating perinal abscess: report of two cases

Fournier's gangrene

Fournier's gangrene (FG) is a synergistic polymicrobial gangrenous infection of the perineum, scrotum and penis which is characterised by obliterative endarteritis of the subcutaneous arteries, resulting in gangrene of the subcutaneous tissue and the overlying skin. FG affects all ages and both genders, with a male preponderance. It is a rare but life-threatening disease, and despite therapeutic advances in recent years, the mortality rate is 3%-67%, with an incidence of 1:7500-1:750,000. Anorectal, genitourinary and cutaneous sources of infection are the most common causes of FG, with diabetes mellitus being the most common risk factor. The clinical condition presents evolution from 2 to 7 days and is characterised by uneasiness, local swelling and discomfort, fever, crepitus and sometimes frank septic shock. Current imaging techniques for initial evaluation of the disease include radiography, Ultrasonography (USG), Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). However, the diagnosis of FG is usually clinical and imaging can be helpful in uncertain diagnosis and when clinical findings are ambiguous. Treatment of FG is based on a multimodal approach which includes intensive fluid resuscitation to stabilise the patient and correction of electrolyte imbalance, if any. This is followed by extensive debridements and resections in order to remove all necrotic and infected tissue, wide spectrum antibiotics and reconstructive surgery, whenever required. However, despite all the advances in treatment today, FG remains a surgical emergency, hence, early recognition with aggressive haemodynamic stabilisation, parenteral broad spectrum antibiotics and urgent surgical debridement are the mainstay of treatment.

[3.0T MRI with a high resolution protocol for the study of benign disease of the anus and rectum. Part 2: Anorectal inflammatory disease. Postsurgical anatomy and complications after treatment]

Benign anorectal disease comprises a broad group of processes with very diverse origins; these processes may be congenital or acquired as well as inflammatory or tumor related. However, benign anorectal disease has received less attention in the scientific literature than malignant disease. In this second part of this image-based review of benign anorectal disease, we describe the most common inflammatory and fistulous diseases, the postsurgical anatomy, and complications that can occur after surgical treatment or radiotherapy for anorectal disease.

Anorectal disorders

Anorectal disorders are commonly encountered in the practice of emergency medicine. Most can be diagnosed and treated in the emergency department setting. Almost all anorectal disorders once diagnosed and treated in the emergency department need appropriate follow-up to ensure adequacy of treatment, for further possible diagnostic procedures (e.g., endoscopy, biopsy), or for definitive treatment. Hemorrhoids are the most prevalent anorectal disorder and are the most common cause of hematochezia. Treatment is dependent on the degree of hemorrhoid prolapse and symptoms. Most cases can be treated by conservative medical treatment (e.g., dietary changes, sitz baths) or nonsurgical procedures (e.g., rubber band liagation, infrared coagulation). Surgical excision of symptomatic thrombosed external hemorrhoids is indicated if within 48 to 72 hours of pain onset. Anal fissures are one of the most common causes of anorectal pain. They are most frequently idiopathic, and most are located in the posterior midline of the anal canal. Most anal fissures are adequately treated by a medical approach using sitz baths, stool softeners, and analgesics. If the anal fissure becomes chronic and is not responsive to medical therapy, a lateral sphincterotomy of the internal anal sphincter is the surgical procedure of choice. Pharmacologic treatment (botulinum toxin or nitroglycerin ointment) to decrease internal anal sphincter tone has shown promise in the treatment of anal fissure. Anorectal abscesses are categorized into four types: perianal, ischiorectal, intersphincteric, and supralevator. Most are idiopathic and contain mixed aerobic-anaerobic pathogens. Fistula formation varies from 25% to 50% and is much more common with gut-derived organisms (e.g., E. coli, B. fragilis). Definitive treatment for an anorectal abscess is timely surgical incision and drainage to prevent more serious complications (e.g., serious infection, extension of the abscess). Anal carcinomas are infrequent, the majority of them being squamous cell or epidermoid carcinomas. The emergency physician must maintain a high index of suspicion and obtain a biopsy of suspicious lesions in order not to miss the diagnosis of a cancer. The most common presenting complaint of anal tumors is rectal bleeding. Combination chemotherapy and radiotherapy have shown promising results in the treatment of anal canal tumors. Bacterial, viral, and protozoal infections can be transmitted to the anorectum via anoreceptive intercourse. Such infections must be considered when a patient presents with rectal pain or discharge, tenesmus, or rectal or perineal ulcers. Proctosigmoidoscopy and rectal cultures may be necessary to determine the cause. Potential rectal complications of HIV infection include infectious diarrhea, acyclovir-resistant strains of HSV2, Kaposi's sarcoma, lymphoma, and squamous cell carcinoma. Rectal injuries may result from penetrating or blunt trauma, iatrogenic injuries, or foreign bodies. Rectal injury should be suspected when a patient presents with low abdominal, pelvic, or perineal pain or blood per rectum after sustaining trauma or undergoing an endoscopic or surgical procedure. Tetanus prophylaxis, intravenous antibiotics, and surgical intervention are indicated in all but superficial rectal tears.

Fournier's gangrene

Fournier's gangrene is the result of a highly lethal and rapidly progressive necrotizing infection of the perineal and genital fascia, with gangrene of the overlying skin. The infection is generally polymicrobial and probably synergistic in nature. Anorectal, genitourinary, and traumatic infections are the most common causes of Fournier's gangrene. The cutaneous manifestations of Fournier's gangrene are merely "the tip of the iceberg" because the infection spreads aggressively along recognized fascial planes. Perioperative fluid resuscitation, cardiopulmonary support, antibiotic therapy, and nutritional support are of major importance in management of the disease; however, examination under anesthesia with aggressive surgical débridement remains the most important aspect of treatment. Multiple surgical procedures may be necessary to bring the infection under control. In the majority of instances, the testes, glans penis, bladder, and rectum are spared destruction because of their separate blood supplies. Diversion of the fecal and urinary streams may not always be necessary but should always be considered on a case-by-case basis. The value of hyperbaric oxygenation in Fournier's gangrene remains unproven, but there are theoretical reasons why it may be beneficial, at least in some cases. Despite optimal medical and surgical management, the mortality rate in Fournier's gangrene still exceeds 40% in many series.

Fournier's gangrene of the scrotum following anorectal disorders

Five cases of Fournier's gangrene of the scrotum following anorectal disorders were encountered in a period of 2 years. Perirectal abscess was the most common associated underlying condition occurring in three patients. E. coli was the predominant organism cultured in all cases. A chronic debilitating condition was encountered in 3 patients. The mortality rate was 20%, but serious life threatening complications occurred in 4 of our patients. Error in diagnosis and delay in initiating medical treatment were the main causes of the high mortality rate associated with the disease. We advocate thorough rectal examination including proctoscopy in all cases of Fournier's gangrene, especially when no obvious source is apparent.

Anal fistula

Anal fistula is a common cause of chronic irritation to both patients and surgeons. Treatment failure rates may be decreased by a good appreciation of normal anorectal anatomy and fistula pathoanatomy, as well as a wide and practical knowledge of the possible treatment regimens. The various treatment options available for acute abscesses as well as simple and complex anal fistulae are presented and discussed. Identification of the patient at risk of postoperative anal incontinence or of the difficult or high fistula may allow treatment in a specialized proctology unit.

Fournier's gangrene following a perianal abscess

Fournier's disease is an uncommon form of gas gangrene involving the scrotum and perineum. Described by Fournier as an idiopathic condition, it must be recognized as a synergistic gangrene secondary, in most cases, to a focus of perianal infection. Urinary tract infection and local trauma follow as possible causal factors. Five cases complicating a perianal abscess observed in a period of 11 years have been treated with urgent aggressive surgical debridement and intensive care support. Full-thickness skin grafts were required in three patients. Hospital mortality occurred in one case. Although combination antibiotic therapy and correct postoperative wound management are potentially successful, the mainstay of treatment is complete excision of all necrotic tissue. Colostomy and urinary diversion are not mandatory. Treatment with hyperbaric oxygen is controversial.

Necrotizing soft-tissue infection from rectal abscess

Rectal abscess may result in necrotizing soft-tissue infection including fasciitis, myositis, and extraperitoneal dissection of pus without muscle necrosis. The presentation and therapy of ten patients treated over the past six years are reviewed. Early recognition of rapidly spreading infection was imperative. The mortality rate of 40 per cent correlated with the degree of sepsis present at admission. The high mortality attendant with the complications of rectal abscess emphasizes the need for aggressive therapy, including frequent examinations under anesthesia, wide debridement, systemic triple antibiotic therapy, diverting colostomy, aggressive wound care, and hyperalimentation.

Fournier's disease: necrotizing gangrene of the male genitalia

Fournier's disease, a necrotizing subcutaneous infection involving the male genitalia, was first described by the French venereologist Jean Alfred Fournier in 1884. Its characteristic triad of abrupt onset in young, previously healthy males, rapid progression to gangrene, and absence of a discernable cause appear to have been altered, at least partially, by the advent of the antibiotic era. We present a case report, with discussion of the clinical and pathophysiological mechanisms involved in this rare and malignant infectious process.

Invasive necrotizing infection secondary to anorectal abscess

During a six-year period, six patients were treated for invasive necrotizing infection secondary to anorectal abscess. The delay in definitive diagnosis and treatment ranged from three to 14 days. All patients had significant concomitant diseases. The number of operative procedures for each patient ranged from one to nine. Antibiotics, as well as nutritional supplementation by the parenteral or enteral route, were used on all patients. Each patient had three or more complications attributable to this infection. Hospital stay ranged from 30 to 76 days. All patients survived. Factors contributing to the development of this condition are delay in diagnosis, inadequate and inappropriate treatment, and concomitant disease. Factors associated with a satisfactory outcome are examination under general or conduction anesthesia by an experienced examiner, prompt and definitive operation therapy (including drainage and removal ov all necrotic tissue), antibiotics, frequent reexamination under general anesthesia, nutritional support, and close attention to concomitant disease.