15 Jul High Risk Abdominal Wounds: Does Delayed Primary Closure Reduce Infection Risk?
Aneel Bhangu, MBChB, MRCS and Douglas M. Bowley, FRCS
Royal Centre for Defense Medicine, Birmingham, England
MedicalResearch.com: What are the main findings of the study?
Answer: Our study was a meta-analysis, which combined the findings from 8 randomized controlled trials that included a total of 623 patients. The key finding was that delayed primary skin closure (DPC) for contaminated and dirty abdominal incisions may reduce the rate of surgical site infection. However, due to high risk of bias from the included studies, including flaws in study design, definitive evidence is lacking.
We believe that this meta-analysis represents an exciting development in biomedical publishing; this was a true collaboration between US and UK military surgeons to examine an area of major concern and interest to surgeons everywhere. This work uses experience hard-won on the battlefields of Iraq and Afghanistan, combined with published surgical trials, to inform both future research activity as well as military and civilian surgical practice. This cross-fertilization of ideas is one positive consequence of all the sacrifice and suffering of recent conflicts.
MedicalResearch.com: Were any of the findings unexpected?
Answer: In our study, a fixed effect model showed that DPC significantly reduced wound infection, but the random effect model did not. The decision about whether to use a fixed or random effect meta-analysis remains hotly debated. Since the data were heterogeneous, the traditional statistical approach is to take the result from the random effects model: that there is no difference between groups. However, as clinicians we can interpret the two different results as indicating uncertainty in the effect. We believe this means that the technique should certainly not be dismissed, as it is a cheap and potentially useful intervention.
MedicalResearch.com: What should clinicians and patients take away from your report?
Answer: Our message for the practicing surgeon is that due to the potential [but not convincingly proven] benefit, DPC has a role for surgical site infection prophylaxis for the high-risk patient. The patient group most likely to benefit are those whose operation can be classed as ‘dirty’. Patient-related factors that would contribute include: presence of shock/requirement for inotropes, pre-existing patient co-morbidity [high ASA grade, immunosuppression, diabetes, steroid use and the obese or a combination of these. Currently, for ‘contaminated’ cases we do not advocate using DPC and suggest that surgeons should continue to follow their own choice of closure.
We are now extending the paradigm of ‘damage control surgery’ beyond the trauma setting into emergency general surgery. Surgeons should be considering the patient’s physiological status and planning their surgical approach appropriately. Think of DPC of the laparotomy wound as a technique of ‘damage control’ for the general surgical patient. So for the midline laparotomy for perforated sigmoid diverticulitis, in the presence of fecal contamination and particularly if there are patient related risk factors, we recommend [and also practice] delayed primary closure of the wound.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Answer: The findings of our study, in particular a borderline effect when considering the random versus fixed effect models, adds fuel to clinical equipoise and demonstrate that this is a particularly good time for a randomized trial. Clinical equipoise means that enough surgeons must believe this to be a significant problem, and to be unsure of the correct way to treat it. Recent evidence shows an increasing culture of randomized, controlled trials [RCTs], and although there has been a recent slight decrease in North American RCTs, the United States remains the country with the highest number of published RCTs. Thus, if there is equipoise and an improving culture towards trials, we put out a call for a multicenter, and hopefully transatlantic, randomized trial.
Systemic Review and Meta-analysis of Randomized Clinical Trials Comparing Primary vs. Delayed Primary Skin Closure in Contaminated and Dirty Abdominal Incisions
Bhangu A, Singh P, Lundy J, Bowley DM. Systemic Review and Meta-analysis of Randomized Clinical Trials Comparing Primary vs. Delayed Primary Skin Closure in Contaminated and Dirty Abdominal Incisions. JAMA Surg. 2013;():1-8. doi:10.1001/jamasurg.2013.2336.