Here, we report a fatal case of postoperative gas gangrene with very acute onset and rapid progression of the symptoms. This case report especially focuses on the risk factors, cause of infection, and treatment methods of postoperative gas gangrene.
Gas gangrene used to be frequent during war times, being related to weapon injuries [6]. In modern clinical practice, the various causes of gas gangrene have included “sterile” operations, intravenous infusion, intramuscular injection, and criminal abortion, etc. [7]. Even if a patient does not have any evident infectious causes, recent abdominal surgical intervention can also contribute to gas gangrene formation. Indeed, several cases of gas gangrene with C. perfringens after abdominal surgery have been recently reported [2, 3]. The onset of symptoms in these cases was 2 weeks and 2 days after the operation, respectively. To our knowledge, our case represents the most acute onset of postoperative gas gangrene with C. perfringens ever reported.
It is well known that both the existence of cancer cells and exposure to anesthetic agents can suppress the immune system, which in turn increases the risk of surgical site infection [8]. In addition, gas gangrene occurs more frequently in diabetics, alcoholics, immunosuppressed patients, IV drug users, and patients with peripheral vascular disease [9]. The risk of postoperative infection in our case may have been increased by the long operation and massive blood transfusion [8]. However, the patient had a past history of exposure to neither anticancer nor immunosuppressive agents. Moreover, she did not have any preexisting co-morbidities other than hyperthyroidism. Hence, she was not considered to have a particularly high risk for development of postoperative gas gangrene. Thus, the cause of fulminant infection with C. perfringens in this patient with no remarkable risk factors is unknown. Molecular typing of toxins and enzymes involved in the virulence of C. perfringens seems to be a powerful tool to clarify this issue. However, we did not assess the toxins and enzymes, which is a limitation of this case report.
We hypothesized that the source of infection in this case might have been the ileum used for bladder reconstruction. Urinary diversion via the bowel might contribute to contamination by bowel microbes [10]. In general, two conditions are necessary for the onset of gas gangrene: (1) the presence of clostridial spores, and (2) an area of tissue hypoperfusion caused by circulatory failure in a local area or by extensive soft tissue damage and necrotic muscle tissue. The occurrence of clostridial species in feces is not rare, a large number of clostridia having been found to be present in normal human feces (106–109/g feces) [7]. In particular, C. perfringens was reportedly detected in 33 % of healthy Japanese adults, and at a concentration of at least 103/g feces [11]. These indicate that endogenous clostridial spores that probably existed in her ileum may have spread into the surgical wound. Abdominal enhanced CT images obtained 1 day after the operation (Fig. 2d, e) showed the presence of air-densities between the subcutaneous fat tissue and muscle layer in the vicinity of the drainage tubes. These CT images support our hypothesis that the drainage tube might have been the source of the C. perfringens infection.
Urgent surgical exploration and debridement of devitalized tissue are crucial for the treatment of gas gangrene. In addition, aggressive antibiotic treatment is also important. The first choice of antibiotics for Clostridium is penicillin [12]. However, we could not use penicillin because she had developed hypersensitivity responses to penicillin with shock at the age of approximately 20 years. Hence, we used IPM/CS and CLDM, which are considered the second choice for Clostridium. It was recently reported that CLDM resistant C. perfringens species are on the increase [1]. In this case, CLDM resistant C. perfringens was detected in the wound abscess. Therefore, we had to discontinue use of CLDM. Although C. perfringens was abolished by our intensive therapy, multidrug-resistant Pseudomonas aeruginosa caused multi-organ failure and, ultimately, death. Similar to what has been seen in many cases of severe sepsis, the secondary infection was likely due to a combination of neutropenia and an adverse reaction to broad spectrum antibiotics.
Despite remarkable progress of multidisciplinary therapeutic methods, including extensive surgical debridement, antibiotic coverage and HBOT, the morbidity and mortality rates of gas gangrene are still very high (up to 57 %) [13, 14]. Given this high mortality rate of gas gangrene, physicians should be aware that any patient could possibly develop gas gangrene after an operation.