Characteristics of Surgical Site Infection Following Colorectal Surgery in a Tertiary Center

Extended-Spectrum beta-Lactamase-Producing Bacteria Culprits in Disease

Eliana Kalakouti, MD; Constantinos Simillis, MD; Gianluca Pellino, MD; Nabeela Mughal, MD; Oliver Warren, MD; Sarah Mills, MD; Emile Tan, MD; Christos Kontovounisios, MD; Paris P. Tekkis, MD


Wounds. 2018;30(4):108-113. 

In This Article


Surgical site infections are of particular concern in large bowel surgery due to the inherent likelihood of antimicrobial contamination at the operative site. The 2014–2015 report on Surveillance of Surgical Site Infections in NHS Hospitals in England,[16] published by Public Health England, reported colorectal surgery as the type of surgery with the highest risk of SSIs, with cumulative incidence risk in the last 5 years at 10.4%. In 1981, Baum et al[4] reported that SSIs occurred in 40% of patients undergoing large bowel surgery in the absence of antibiotic prophylaxis.

Wound infection is a sobering burden on health care outcomes as it increases the risk of morbidity and mortality, likelihood of admission to intensive care, length of hospital stay, and the economic implications of prolonged medical care.[17–21] In 2004, Nespoli et al[22] reported the survival rates in patients who underwent surgery for removal of colon cancer were reduced in the presence of a surgical wound infection.

The national clinical guidelines produced by the Scottish Intercollegiate Guidelines Network (SIGN), updated in 2014,[10] report that the numbers needed to treat (NNT) with antibiotic prophylaxis to prevent SSI or an intra-abdominal abscess in colorectal surgery is 4. When compared with other surgeries, such as hepatobiliary where the NNT is 11, it is made clear that prophylaxis is highly applicable and beneficial to colorectal surgery.[8] Further supportive evidence is found in a Cochrane meta-analysis, which demonstrates up to a 75% reduction in postoperative wound infections with prophylaxis.[8] A national study assessing real-world use of prophylactic antibiotics in open colectomies showed up to a 44% decrease in SSIs depending on the choice of antibiotic.[23] The aforementioned statistics show the appropriate choice of antimicrobial prophylaxis can prevent postoperative wound infections and hence contribute to better patient outcomes and safer care in colorectal surgery.

This study was mainly fueled by the sincere concerns of the authors' colorectal team who found that, despite great advancements in surgical care progressing colorectal surgery towards enhanced recovery, SSIs remained an obstacle to optimal patient care. The data revealed that 21% of the colectomies completed in this tertiary center were complicated by a SSI, which is higher than the national average. Insight into the factors accountable for this is crucial to overcome existing challenges and guide better practice in the management of surgical wound infections.

The main findings of this study showed that 38% of wound infections after colorectal surgery in the tertiary center were due to ESBL-producing pathogens. This finding revealed that more than one-third of the infections were resistant to the empirical antibiotic prophylaxis (ie, amoxicillin-clavulonic acid), which defeats the purpose and benefits of preemptive antimicrobial administration. This indicates that inadequate empirical antibiotic prophylaxis is a potential contributor to the high incidence of SSIs.

The ESBL production undermines the effectiveness of prophylactic antimicrobials, which have so far been a failsafe mechanism against SSIs. It is an important risk factor for increased mortality in infections and a major determinant of resistance against β-lactams.[24] Considering that β-lactams account for more than 50% of all global antibiotics in use, the ESBL phenomenon is threatening to jeopardize an era of relatively safe colorectal surgery by complicating previously easily treatable infections.[25–27] Empirical antibiotic treatment needs to account for the emerging challenges of multidrug resistance, and ESBL-producing pathogens need to be addressed more aggressively.