Dangers of delayed diagnosis of perianal abscess and undrained perianal sepsis in Fournier’s gangrene: a case series
- 1 Department of Surgery, Westmead Hospital, Westmead, New South Wales, Australia
- 2 Western Sydney Local Health District, Westmead, New South Wales, Australia
- 3 Department of Surgery, Blacktown Hospital, Blacktown, New South Wales, Australia
- 4 Department of Colorectal Surgery, Westmead Hospital, Westmead, New South Wales, Australia
- Correspondence to Dr Edgardo Solis; edgardosolis4@gmail.com
Abstract
Fournier’s gangrene (FG) is a rapidly progressing infective necrotising fasciitis of the perianal, perineal and genital region. It is characterised by its aggressive nature and high mortality rates of between 15% and 50%. While it has been commonly found to primarily develop from urological sources, there have been increasing reports of the role of colorectal sources as the underlying aetiology of FG. Presented is a case series of four FG presentations at a single institution during a 12-month period as a result of underlying untreated perianal disease highlighting its dangers in progressing to a deadly infection, advocating for early and aggressive surgical debridement, and the role of adjunct scoring systems, such as Laboratory Risk Indicator for Necrotising Fasciitis, in guiding clinical diagnosis.
Background
Fournier’s gangrene (FG) is a rapidly progressing infective necrotising fasciitis of the perianal, perineal and genital region.1 Its pathophysiology is characterised by vascular thrombosis, endarteritis and subsequent skin and tissue necrosis.2
The first documented case of genitalia gangrene was associated with a traumatic injury described by Baurienne in 1764.3 In 1883, Fournier described the condition in a case series of four young healthy men, also with traumatic injuries.4 Within the literature, a urological source has been reported to be the primary cause.5 However, there have been increasing reports of FG being associated with undrained perianal sepsis.1 6 These may be associated with anal fistulae, rectal trauma and, rarely, rectal carcinoma.1 It may be monomicrobial or polymicrobial, and is associated with high mortality rates of between 15% and 50%.2 6 The condition mostly occurs in men between 50 and 60 years of age with major risk factors, including diabetes, alcoholism, lymphoproliferative disease and HIV.1 7
In its early stages, FG may be difficult to diagnose, but as it can spread rapidly and its impact may be devastating, a high index of suspicion is required for patients with severe perianal infection and signs of sepsis. Early diagnosis and aggressive surgical debridement are vital.8 In this case series, we have presented a series of four FG cases encountered in a 12-month period at a single institution. Underlying perianal disease was the primary aetiology in all four FG cases.
Case presentation
Case series
Case 1: delayed presentation of ischiorectal abscess
A 72-year-old man, with a background history of smoking, presented to the emergency department after a 7-day history of worsening perianal pain. He had been started on oral antibiotics by his general practitioner but failed to improve and subsequently presented to the emergency department. On examination, he had a painful area of induration and erythema in his perineal region. His initial blood panel demonstrated a white cell count of 33.2×109, a haemoglobin of 101 g/L and a C reactive protein (CRP) of 298 mg/L. The patient had new-onset atrial fibrillation. A CT demonstrated a 9.6×4.8 cm gas-containing abscess within the left ischiorectal region (figure 1) and the patient was suspected to have necrotising fasciitis of the perineum. The patient underwent a wide debridement of his perineum, including drainage of the large left ischiorectal abscess, with no associated fistulating disease. Following debridement, he was commenced on meropenem, clindamycin and vancomycin, with a planned relook debridement 24 hours later, showing further devitalised tissue that was debrided. Due to the wide area of debridement performed close to the anus, the wound was at high risk of faecal contamination and a defunctioning Abcarian colostomy was fashioned. The patient stabilised on antibiotics and after 2 weeks was changed to an oral course of ciprofloxacin and clindamycin and the wound was managed with negative pressure wound therapy (NPWT) for 1 month. Following this, a local advancement flap was performed successfully, and the patient was discharged 47 days after the initial presentation.
CT scan (axial view) demonstrating a gas-containing abscess within the left ischiorectal region (red outline).
Case 2: delayed presentation of scrotal pain and swelling
A 46-year-old man presented with a 2-week history of scrotal pain and swelling. He also had perianal pain but his main complaint was around his scrotal region. He was a smoker and overweight but reported no other medical conditions. He presented unwell with tachycardia, diaphoresis and necrotic skin changes over his scrotum. On examination, there was necrosis and crepitus over the scrotum, and a diagnosis of FG was made (figure 2). He was taken to the operating theatre immediately for a wide debridement. There was extensive necrosis over the perineum and scrotum, with the greatest area of necrotising infection stemming from a right ischiorectal abscess (figure 3), and had an associated anorectal fistula (figure 4). An Abcarian colostomy was fashioned by a minimally invasive laparoscopic technique. The patient required serial debridement of devitalised tissue and was commenced on meropenem, clindamycin and vancomycin. After 7 days, this was changed to oral ciprofloxacin and clindamycin. The patient was subsequently managed with NPWT. The wound was closed primarily 2 weeks after presentation and the patient was discharged successfully on day 19.
Necrosis of the scrotum with associated crepitus on examination.
Extensive area of necrosis debrided, with greatest area of necrotising infection around the right ischiorectal space with associated fistulating disease.
Seton in the right ischiorectal space with associated fistulating disease (red circle).
Case 3: patient with diabetes and end-stage renal failure with worsening perineal erythema and pain, with sudden deterioration
A 57-year-old man with diabetic nephropathy and end-stage renal failure on haemodialysis had a 1-week history of perineal erythema and 1-day history of pain. The patient experienced sudden deterioration with signs of sepsis, including tachycardia, hypotension and diffuse perineal pain. A CT demonstrated bilateral perineal region fat stranding and subcutaneous emphysema consistent with FG . An urgent perineal debridement was performed. The necrotising tissue extended posteriorly to the perianal area. The patient initially had a difficult course in the intensive care unit, but after serial debridement and antibiotics, the patient stabilised and an NPWT was used to control the sepsis. An NPWT system, which allowed for the instillation of debriding Prontosan fluid into the wound, was used. Initially, a faecal management system was used in an attempt to facilitate negative pressure dressings without a stoma. However, due to difficulties associated with faecal contamination, the patient required a diverting ileostomy. After several months of NPWT, a split-thickness skin graft was used but there was significant wound breakdown. Fortunately, the wound completely healed by secondary intention. After 127 days, the patient was discharged to a respite facility.
Case 4: neurosurgical inpatient with sudden onset of scrotal swelling and deterioration
A 69-year-old man recovering from a craniotomy for meningioma suddenly developed scrotal swelling, on a background history of previous FG. He was seen by a urologist and commenced on oral ciprofloxacin. However, he developed high-grade fever and deteriorated, and was found to have an ischiorectal abscess that was drained by a general surgeon. However, the patient failed to improve, with worsening perianal pain. At the same time, he developed atrial fibrillation and was commenced on apixaban. After specialist colorectal consultation, the patient was diagnosed with FG. The initial abscess drainage did not adequately drain all the pus. The second operation revealed an anorectal fistula and necrotising fasciitis in the ischiorectal fossa. The patient was immediately taken to the theatre and a wide debridement of his scrotum, perineum and perianal region was performed. A seton was placed into the fistula and a defunctioning Abcarian colostomy was performed. After several debridements, NPWT was applied to the wound and the patient was commenced on meropenem and vancomycin. The patient was changed to metronidazole after 1 week. Enterococcus faecium was isolated from the ischiorectal abscess and daptomycin was added to the antibiotic regimen. A local flap repair was performed and the wound healed well. The patient was discharged successfully 56 days after his initial craniotomy surgery.
Outcome and follow-up
All patients have recovered well with no significant morbidity and no mortality. The patients from case 1, 2 and 4 have all had a reversal of stoma within 1 year from their initial surgery and have had complete wound healing.
The patient from case 3 has had ongoing management of his fistulating disease with regular colorectal review and is currently awaiting reversal of stoma.
Discussion
FG has been commonly associated with urological conditions which include urethral strictures, renal stones, epididymitis and surgery of the penis and scrotum.1 2 6 However, increasingly, anorectal pathology has been identified as the primary aetiology.1 A review by Eke of 1726 FG cases noted that anorectal conditions accounted for 21% of cases while urological causes accounted for 19%.6 The majority of cases reporting the association between anorectal pathology and FG has been described in case reports and case series, with rare cases also described as a result of rectal carcinoma.5 8 9 For all presented cases in this case series, an underlying perianal disease was identified as the source of sepsis. Two cases were associated with anorectal fistulising disease. This case series conveys the importance of not overlooking perianal sepsis in the development of FG and the potential danger of delayed management of perianal sepsis.
FG is commonly seen as a disease of men, with associated risk factors, including diabetes, smoking and immunocompromised states such as those seen in HIV or lymphoproliferative disease.6 7 Diabetes is associated with about 65% of cases as it predisposes patients to infections due to disturbed microcirculation, dysfunctional neutrophils and hypofunctional immune system.7 Our case series reflected these associated risk factors as two patients had a background history of diabetes mellitus and two patients were active smokers. In patients who have underlying perianal disease and associated risk factors, surgical teams should maintain a high level of clinical suspicion for the potential development of FG and ensure adequate treatment of perianal disease.
Despite its well-known severity and need for urgent surgical management, FG remains a difficult entity to diagnose, particularly in its early stages as it can be indistinguishable from cellulitis or abscesses.10 The diagnosis of FG remains primarily clinical in nature, with its most common features including localised tenderness and swelling of the perianal or genital region, fever, tachycardia and hyperglycaemia.1 2 The Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score was developed to assist in risk stratification and early recognition of FG even in its early stages. The parameters measured include CRP, white cell count, haemoglobin, sodium, creatinine and glucose.10 Bechar et al’s systematic review of LRINEC scoring supported its use as an adjunct in the clinical diagnosis of necrotising fasciitis.11 A score of ≥6 should raise a suspicion of necrotising disease and a score of ≥8 is strongly predictive.10 The median LRINEC score in our presented patients was 9 (range 3 to 11), a score indicating high risk of necrotising fasciitis. The Fournier’s gangrene severity index (FGSI), described by Laor et al, provides a predictive measure of mortality. An FGSI score greater than 9 predicts a mortality probability of 75% while a score of 9 or less was associated with a 78% probability of survival.12 The Uludag FGSI (UFGSI) combines the extent of disease, age and FGSI to provide a scoring system that predicts a 94% probability of death with a score greater than 9, and an 81% probability of survival with a score of 9 or less.13 These scoring systems can be useful adjuncts in guiding clinical diagnosis as well as predicting mortality risk of FG; however, it may not always be accurate as seen in one of the presented cases in which the LRINEC score was 3.
Delayed diagnosis and delayed operative debridement are associated with increased mortality rates.10 The mainstay management of FG involves haemodynamic resuscitation, broad-spectrum antibiotics and early aggressive surgical debridement of all involved necrotic tissue. Of consideration, faecal diversion through colostomy should be considered in cases involving the anorectal area and those with high risk of faecal contamination.2 Continued exposure to faecal contamination can aggravate sepsis and delay wound healing, as well as placing a burden on nursing resources and discomfort to the patient with the need of frequent dressing changes.14 Faecal diversion can be achieved through stoma formation or use of flexible faecal management systems (Flexi-Seal), with stomas being the traditionally the preferred method. While recent studies show similar outcomes in wound healing and length of stay between stoma and flexible faecal management systems, the role of each intervention is dependent on extent of disease.14–16 Ozturk et al’s prospective comparison of stoma versus non-stoma faecal management showed that patients with FG from an anorectal source required stoma formation more frequently than those with a urinary source of FG.15 Flexi-Seal can be useful in select patient populations such as cases in which the anal sphincter is not involved.14–16 However, each management system has associated risks that need to be considered. Stoma formations carry an increased cost to the healthcare system, require a second surgery for reversal and have the associated complications of the procedure itself.15 16 Flexi-Seal risks include pressure ulcers, bleeding from ulceration and sphincter damage.14 15 In all four cases in this series, a diverting stoma was created as part of their management; one patient was initially trialled with flexible faecal management but failed to achieve adequate faecal diversion. As such, we advocate for the use of stoma formation for faecal diversion, as in the emergency setting, it can be difficult to adequately assess sphincter preservation for the use of Flexi-Seal. Surgical debridement occurred within 12 hours of presentation in three cases. Appropriate broad-spectrum antibiotic cover is vital in managing FG to combat a usually polymicrobial entity in which aerobic and anaerobic bacteria work synergistically to cause a fulminant and aggressive necrotising infection.6 In this study, two cases were associated with polymicrobial infections, of which one case was due to three separate organisms: vancomycin-resistant Enterococcus E. faecium, multi-resistant Klebsiella pneumoniae and Pseudomonas aeruginosa.
The presented case series highlights the dangers of perianal sepsis. In patients with severe perianal pain that is out of proportion, signs of sepsis and scrotal swelling especially in elderly patients with significant comorbidities such as renal failure, diabetes or who are immunosuppressed, clinicians must have a high index of suspicion for FG. Perianal abscesses if not adequately drained may lead to a devastating fulminant soft tissue infection that poses a significant threat to a patient’s life and causes significant morbidity if not mortality. Early presentations may pose a clinical diagnostic dilemma; however, the use of adjunct scoring systems such as the LRINEC score can assist clinicians in risk stratifying patients. We advocate for early intervention, aggressive surgical debridement and faecal diversion in the management of FG.
Learning points
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Early Fournier’s gangrene (FG) may pose a clinical diagnostic dilemma, the use of adjunct scoring systems, such as the Laboratory Risk Indicator for Necrotising Fasciitis score, can assist clinicians in risk stratifying patients.
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The role of untreated perianal disease cannot be underestimated in its potential to progress to FG.
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Early intervention and aggressive surgical debridement remains the mainstay treatment of FG.
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Negative pressure wound therapy is a valuable tool in managing FG wounds postoperatively as is faecal diversion in managing wound contamination.
Footnotes
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Contributors ES and YL were involved in the acquisition of data, analysis and interpretation of data, and writing of manuscript. JWTT and GC participated in the conception and design, interpretation of data and reviewing of manuscript.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Patient consent for publication Obtained.
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Provenance and peer review Not commissioned; externally peer-reviewed.
- © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.
References
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