NSTI initially as Fournier’s gangrene after Jean Alfred Fournier, NSTI is a progressive extensive fascial necrosis that was first described in 1764 as a fulminant gangrenous infection of the scrotum (5). The term “necrotizing fasciitis” was first introduced in 1952 (6). Although the incidence of NSTI is quite low (1: 200,000), the mortality rate of up to 76% makes it a highly fatal surgical complication (7, 8).
The main predisposing risk factors for NSTI include diabetes, obesity, immunosuppression, malignancies, alcoholism and malnutrition. our patient was an obese woman and already had a GI cancer that were her predisposing factors for this fatal complication. Any bacterial inoculation in the sub-epithelial and sub-mucosal tissue could potentially cause NSTI. From microbiology standpoint, NSTI are classified to three subtypes (Table 1): 1-polymicrobial including anaerobes, 2- monomicrobial, mainly Group A β-hemolytic streptococci including Streptococcus pyogenes and Staphylococcus aureus and 3-Marine Gram-negative bacilli (1).
Table 1.
Tim Line
| Description |
---|
Patient information | a 65 year old obese (BMI = 36) but healthy looking woman with chronic abdominal pain and rectorrhagia for several months |
Diagnostic assessments | Three adenomatous polyps in the splenic curvature was seen on colonoscopy. CT scan was normal |
Interventions and treatment | The patient was underwent laparoscopic total colectomy and ileorectal anastomosis |
On the 4th day after surgery | Severe abdominal pain and distension was occurred along with discoloration of abdominal skin |
The 5th day after surgery | Eccymotic and necrotic patch was appeared on abdominal skin and the patient became febrile and tachycard. |
The 5th day after surgery | First surgical debridement was done and antibiotic initiated. |
The 8th day after surgery | Second surgical debridement. |
The 12th day after surgery | Third surgical debridement. |
The 14th day after surgery | The patient discharged with medically stable condition with an open wound |
Fallow up: 10 days after discharge | The patient was stable and the wound was clean based |
Fallow up: 1 month after discharge | The patient was medically fit and the wound was ready to be closed |
3 month’s after surgery | The abdominal wound been closed secondarily. |
While the rate of wound infection is compatible in laparotomy and laparoscopic incisions (9), the incidence of NSTI has been reported to be lower in laparoscopic colon surgeries compared to laparotomy (0.7% vs 4.1%) (10, 11). Iatrogenic perforations and low tissue oxygenation could contribute to NSTI following laparoscopic procedures (12).
The most crucial determinant in NSTI outcome is timely diagnosis. However, given that the skin is largely spared in laparoscopic surgeries; the early presentations of NSTI could be difficult to distinguish from other non-necrotizing soft tissue infections such as cellulitis (13). Findings such as foul smelling ‘‘dishwater pus’’ like discharges and lack of tissue resistance to blunt dissection raise the suspicion for NSTI diagnosis (14).
The use of high T2-weighted magnetic resonance imaging (MRI) in early diagnosis of NSTI has been considered (15). Although, MRI could be useful in differentiating NSTI from other superficial soft tissue infections, the lack of specificity and the fact that it might not be available to many centers, make it an unavailable option for early diagnosis of NSTI (16). Differentiating the pathology of the soft tissue infection using frozen section biopsies could be also helpful for early diagnosis of NSTI. However, this could not be considered as a standard practice (13).
The laboratory risk indicator for necrotizing fasciitis (LRINEC) score is a simple tool and is easy to estimate in most clinical settings (17). It is based on C-reactive protein (CRP), hemoglobin level, Leukocyte count and serum levels of sodium, creatinine, and glucose. The LRINEC score has a positive predictive value and negative predictive value of 92% and 96% respectively (17).
Here, we presented a case of NSTI following laparoscopic total colectomy due to early stage colon adenocarcinoma. Our patient did not have any underlying predisposing factor except obesity and underlying cancer, and had not received any immunosuppressive anti-cancer therapy. We made the diagnosis as soon as five days after index operation based on our clinical observation. The LRINEC score in our patient was 6 (CRP > 150 and Hb < 11) (17). The responsible microorganism was found to be Enterococcus faecalis. Given that no anaerobic bacteria growth, we concluded that our case was a type II monomicrobial NSTI (1). However, Enterococci have not been reported as the main microbiological cause of the type II NSTI (Table 2).
Table 2.
Necrotizing Soft Tissue Infections Subtypes (1)
| Microbial Pathogens | Anatomical Location | Predisposing Factors | Clinical Clues |
---|
Type I | Polymicobial, including anaerobes | Mostly trunk and genitalia | Age, Diabetes, IV drug abuse | Progressive pain, foul smelling wound, tissue crepitus, sepsis |
Type II | Monomicrobial most commonly Group A β-hemolytic streptococci | Not specific | Trauma, IV drug abuse | Septic shock |
Type III | Gram-negative marine organisms | Not specific | Sea food, direct wound exposure | Rapid multisystem organ failure |
Figure 1.
Before Debridement on the 4th Day After Index Surgery, We Found Ecchymotic and Necrotic Tissue on the Patient’s Skin
Figure 2.
2 Days After Primary Debridement, There is Still Echcymotic and Necrotic Tissue
Figure 3.
All Infected Tissue Debrided After 3rd Surgical Debridement
Figure 4.
Ready for Secondary Closure, This is 2 Weeks After Discharge of Patient From Hospital
3.1. Conclusions
Our patient underwent an uncomplicated laparoscopic colectomy and had a moderate risk for NSTI (LRINEC score of 6). By early diagnosis and use of broad spectrum antibiotics and repetitive surgical debridement, increases the survival chances for the patient. The wound swab culture grew Enterococcus faecalis, which is not a usual monobacterial NSTI. An important point in prevention of NSTI in patients like our patient is that the surgeon should be aware of immunity compromise in patients with malignant disease and increased risk of postsurgical infection (including NSTI) in these groups especially in obese patients - like our patients- and maybe the most important way to prevent this complication in this group of patients is high suspicion and early intervention.
3.2. Ethical Consideration
Declaration of Helsinki (1975 revision) regarding patient’s rights has been considered in all steps of performing the study, moreover, we inform the patient about this article after she cure and reassure her about her rights and patient consent was achieved.
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