Fournier’s Gangrene With Subcutaneous Emphysema of the Thigh Caused by Air Inflow Associated With a Rectovaginal Fistula: A Case Report of Pseudo-gas Gangrene

When emphysema of the thigh with strong inflammation is observed, it is necessary to consider necrotic soft tissue infection such as gas gangrene and perform debridement immediately.¹ Gas gangrene, an infection with gas-producing organisms, is a medical emergency of significant morbidity; however, emphysema of the thigh as a first sign of disease other than gas gangrene also exists.^2,3 Previous studies^4,5 reported emphysema of the thigh following disease originating in the intra-abdominal region, such as perforation due to carcinoma of the colon, diverticulitis, or appendicitis.However, to the authors’ knowledge, emphysema of the thigh associated with a rectovaginal fistula (RVF) has never been reported. Herein the authors report a case of pseudo-gas gangrene of the thigh caused by air inflow associated with an RVF in a patient with Fournier’s gangrene.

A 61-year-old female patient presented to her family doctor with a swollen left lower limb. The patient was diagnosed with cellulitis and administered intravenous cefazolin. The left thigh and left lower abdomen exhibited swelling combined with crepitus 3 days later. Because gas gangrene was suspected, the patient was transported to the authors’ emergency department. The patient had nephrotic syndrome for more than 40 years and was taking 15 mg prednisolone daily. On admission, the patient had a fever of 37.7°C, and the left thigh and left lower abdomen displayed swelling combined with crepitus (Figure 1). Hematological studies revealed a white blood cell count of 34.0×10⁹/L and C-reactive protein level of 30 mg/dL, which were indicative of severe inflammation. An axial computed tomography scan showed air in the soft tissue of the left thigh, left buttock, perineal region, and left lower abdomen (Figure 2).

Because gas gangrene was suspected, the patient was administered 500 mg of meropenem every 8 hours, 600 mg of clindamycin every 12 hours, and 500 mg of vancomycin every 12 hours, and emergency surgery was performed. An intraoperative examination revealed a severe soft tissue infection in the left buttock, and necrosis was noted in the gluteus maximus muscle. Furthermore, a large amount of a pus-like discharge was emanating from the patient’s vagina (Figure 3). Colposcopy and a digital rectal examination were performed by a gynecologist (ie, one of the present authors); however, there was no indication of a fistula connecting to the wound. No inflammatory signs were observed in the left thigh; however, subcutaneous free air was detected (Figure 4).

The patient was diagnosed with Fournier’s gangrene of the buttocks, which was not a complication of necrotizing fasciitis of the left thigh. Postoperatively, the patient’s temperature and other vital signs returned to normal; however, the pus-like discharge continued from the sutured wound on her left buttock. Vaginal or rectal fistulas connecting to the wound were suspected again. On day 8 following debridement, fecal matter was discharged from the vagina. An RVF was suspected and subsequently detected by colon fiberscopy (Figure 5). There was no obvious diverticula or malignant tumor around the fistula. The patient underwent resurfacing surgery with a free skin graft 15 days after the primary surgery. At the same time, a colon stoma was fashioned. Thus, complete resting of the bowel via colostomy was obtained. There was no exudate from the wound and vagina after the stoma construction, and wound healing was successfully achieved even though the patient had poor wound healing capacity. The patient was discharged 14days following the resurfacing surgery in a good condition (Figure 6). Six months following surgery, the patient walked with a cane and did not complain of vaginal or anal exudate (Figure 7). The absence of colonic diverticula and malignancy was confirmed by colonoscopy, and the authors suggested closure of the stoma to the patient; the patient did not wish to close the stoma for fear of recurrence. The patient has been followed up by her family doctor; however, no recurrence has been reported for more than 2 years.

Generally the result of infection by gas-producing organisms in muscles or soft tissues, as typified by gas gangrene, subcutaneous emphysema is detected under conditions with strong inflammatory findings due to bacterial infections. However, in several case reports, patients presented with subcutaneous emphysema of the buttocks and/or thigh caused by gastrointestinal conditions, such as perforation of the bowel due to carcinoma of the colon, diverticulitis, and appendicitis.^4,5 Regardless of its cause, subcutaneous emphysema of the thigh with strong systemic symptoms is a serious condition. Lee et al⁴ reported that subcutaneous emphysema resulting from gastrointestinal perforation and fistulous tract formation or by the direct spread of an abscess produces a mortality rate of approximately 50%; the mortality rate is 80% in instances of spontaneous myonecrosis. Therefore, when signs of subcutaneous emphysema are detected on axial computed tomography images, patients with strong inflammatory findings should undergo debridement as soon as possible. To the best of the authors’ knowledge, this is the first reported case of subcutaneous emphysema of the thigh caused by air inflow associated with an RVF.

Rectovaginal fistulas are defined as abnormal connections between the rectum and vagina.⁶ The most common causes of RVF include obstetric injuries, surgical trauma, radiation, inflammatory bowel disease, and malignant neoplasms of the pelvis.^7,8 The most frequent cause of RVF is obstetric injuries, followed by inflammatory bowel disease.⁶

The RVF in this case was managed by creating a colostomy. As Akiba et al⁹ stated, diverting the stoma is an effective therapeutic option for a perineal wound caused by intrapelvic fistula-related infections with patients who are compromised. Lalwani et al¹⁰ reported that the use of a temporary diverting stoma may facilitate healing, which they found in 10 of their 25 cases that had undergone previous attempts at repair elsewhere but were unsuccessful. The authors¹⁰ were able to repair the RVFs in all 10 patients: 4 with a gracilis flap, 2 with a rectus abdominis flap, 3 with omental reinforcement, and 1 with an ileostomy alone. The prevention of intestinal contents passing through the fistula by diverting the stoma appeared to have been effective in treating the RVF in the present patient who had poor wound healing capacity.^9,10

The authors presented only 1 case of successful treatment of RVF detected by emphysema of the thigh in this report, and as such, this report is limited to a rare experience.

The authors reported a case of Fournier’s gangrene combined with subcutaneous emphysema of the thigh caused by air inflow associated with an RVF. Fournier’s gangrene and the RVF were treated with a combination of emergency debridement and complete resting of the bowel via colostomy. In the present case, the authors believe appropriate treatment of the RVF was necessary to avoid the exacerbation of Fournier’s gangrene and prevent necrosis spreading to the thigh.

Authors: Sho Yamakawa, MD¹; Masaki Fujioka, MD, PhD²; Kiyoko Fukui, MD³; Haruka Matsuo, MD³; Miho Noguchi, MD³; Touta Kugiyama, MD³; Sou Sugimi, MD³; Hiroko Fukuda, MD³; and Kenji Hayashida, MD, PhD¹

Affiliations: ¹Shimane University, Shimane, Japan; ²Nagasaki University, Nagasaki, Japan; ³National Hospital Organization Nagasaki Medical Center, Nagasaki, Japan

Correspondence: Sho Yamakawa, MD, Division of Plastic and Reconstructive Surgery Faculty of Medicine Shimane University, 89-1 Enya-cho, Shimane 693-8501, Japan; yamakawashoright@yahoo.co.jp

Disclosure: The authors disclose no financial or other conflicts of interest.