+
MODEL
Journal of Plastic, Reconstructive & Aesthetic Surgery (2014) xx, 1e3
CORRESPONDENCE AND COMMUNICATION Does primary closure for dog bite wounds increase the incidence of wound infection? A meta-analysis of randomized controlled trials Dear Sir, Dog bites are the most common bite injury. Dog bite wounds are classified as contaminated and contain a mixture of aerobic and anaerobic organisms, both from the victim’s skin and the dog’s mouth. The decision to primarily close dog bite wounds remains controversial, and current data on the risk of infection are variable and inconsistent.1 We conducted a systematic review and a meta-analysis of randomized controlled trials (RCTs) to investigate the wound infection outcome between primary closure and conservative management in dog bite wounds. We searched the PubMed database from 1966 to April 2014 by using the following key words: dog bite and wound closure or sutures. We compared the wound infection outcome between primary closure and conservative management, including non-closure or delayed closure. We excluded the non-English articles and studies that are not RCTs. This search was supplemented by a review of reference lists of potentially eligible studies. Two reviewers independently extracted data in two steps: titles and abstracts, and then full text articles. The Cochrane Collaboration Handbook was used for methodological quality assessments of the included RCTs. Six criteria items were evaluated for each trial, including sequence generation, allocation concealment, blinding, incomplete outcome data addressed, free of selective outcome reporting, and other possible sources of bias. We used the RevMan 5.0 (Review Manager Version 5.0, Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2008) for meta-analysis. Results of the meta-analysis were assessed using risk ratio (RR) with 95% confidence intervals (CI) within a random effects model. The Mantel-Haenzsel method was used for dichotomous outcome. We explored variability in study outcomes by calculating statistical heterogeneity with chi-square and inconsistency (I2)
statistics; I2value of 50% or more represented substantial heterogeneity. Through our literature search we identified four RCTs and included 998 participants overall (Table 1). The primary outcome in all trials was the incidence of wound infection. Three trials analyzed the wound cosmesis as the secondary outcome.2,3,5 For the methodological quality of the included trials, only Rui-feng C et al.4 used adequate random allocation sequences and the exact method of randomization was unclear in other trials. Xiaowei Z et al.3 and Paschos et al.5 had adequate allocation concealment; in other trials, it was unclear whether allocation concealment was performed. Because of the nature of wound closure trials, it was impossible to perform blinding except for blinding of the person who evaluated wound cosmesis.3,5 Paschos et al.5 compared primary closure and conservative management for dog bite wounds in different body parts but did not report the number of wound infection in different body parts. Among the four trials, Rui-feng C et al.4 recruited the largest patient number but evaluated facial dog bite wounds only. Xiaowei Z et al.3 and Paschos et al.5 reported the use of Amoxicillin/Clavulanate in their trials and another two declared not using any antibiotics (Table 1). The meta-analysis included 542 wounds/patients randomized to primary closure and 529 wounds/patients to non- or delayed closure. The meta-analysis demonstrated that there was no statistically significant difference in the incidence of wound infection (38/542, 7.0% versus 40/529, 7.6%; RR Z 0.93, 95% CI, 0.60 to 1.42; P Z 0.72). Studies were of low heterogeneity (I2 Z 0%; P Z 0.74) (Figure 1). Based on the current evidence, though with flaws in research methodology, primary closure for the dog bite wounds would not increase the incidence of wound infection.
Conflict of interest statement There is no potential conflict of interest that exists. No funding was received. All authors have no financial and personal relationships with other people or organisations that could inappropriately influence this work. Ethical approval not required.
http://dx.doi.org/10.1016/j.bjps.2014.05.051 1748-6815/ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Cheng H-T, et al., Does primary closure for dog bite wounds increase the incidence of wound infection? A meta-analysis of randomized controlled trials, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/ 10.1016/j.bjps.2014.05.051
2
Characteristics of included randomized controlled trials comparing primary closure and non or delayed closure for dog bite wounds. No. of patients or wounds randomized
Mean age (range)
Remarkable wound characteristics
Prophylactic antibiotics
Follow-up period
Variables analyzed
Maimaris C et al., 19982
UK
169 wounds (96 patients)
44% of wounds on the hand. 55% of wounds were 1 cm or less
Not given
14 days
Rui-feng C et al., 20134
China
600 patients
N/A (2e83) 60% patients were
MODEL
Journal of Plastic, Reconstructive & Aesthetic Surgery (2014) xx, 1e3
CORRESPONDENCE AND COMMUNICATION Does primary closure for dog bite wounds increase the incidence of wound infection? A meta-analysis of randomized controlled trials Dear Sir, Dog bites are the most common bite injury. Dog bite wounds are classified as contaminated and contain a mixture of aerobic and anaerobic organisms, both from the victim’s skin and the dog’s mouth. The decision to primarily close dog bite wounds remains controversial, and current data on the risk of infection are variable and inconsistent.1 We conducted a systematic review and a meta-analysis of randomized controlled trials (RCTs) to investigate the wound infection outcome between primary closure and conservative management in dog bite wounds. We searched the PubMed database from 1966 to April 2014 by using the following key words: dog bite and wound closure or sutures. We compared the wound infection outcome between primary closure and conservative management, including non-closure or delayed closure. We excluded the non-English articles and studies that are not RCTs. This search was supplemented by a review of reference lists of potentially eligible studies. Two reviewers independently extracted data in two steps: titles and abstracts, and then full text articles. The Cochrane Collaboration Handbook was used for methodological quality assessments of the included RCTs. Six criteria items were evaluated for each trial, including sequence generation, allocation concealment, blinding, incomplete outcome data addressed, free of selective outcome reporting, and other possible sources of bias. We used the RevMan 5.0 (Review Manager Version 5.0, Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2008) for meta-analysis. Results of the meta-analysis were assessed using risk ratio (RR) with 95% confidence intervals (CI) within a random effects model. The Mantel-Haenzsel method was used for dichotomous outcome. We explored variability in study outcomes by calculating statistical heterogeneity with chi-square and inconsistency (I2)
statistics; I2value of 50% or more represented substantial heterogeneity. Through our literature search we identified four RCTs and included 998 participants overall (Table 1). The primary outcome in all trials was the incidence of wound infection. Three trials analyzed the wound cosmesis as the secondary outcome.2,3,5 For the methodological quality of the included trials, only Rui-feng C et al.4 used adequate random allocation sequences and the exact method of randomization was unclear in other trials. Xiaowei Z et al.3 and Paschos et al.5 had adequate allocation concealment; in other trials, it was unclear whether allocation concealment was performed. Because of the nature of wound closure trials, it was impossible to perform blinding except for blinding of the person who evaluated wound cosmesis.3,5 Paschos et al.5 compared primary closure and conservative management for dog bite wounds in different body parts but did not report the number of wound infection in different body parts. Among the four trials, Rui-feng C et al.4 recruited the largest patient number but evaluated facial dog bite wounds only. Xiaowei Z et al.3 and Paschos et al.5 reported the use of Amoxicillin/Clavulanate in their trials and another two declared not using any antibiotics (Table 1). The meta-analysis included 542 wounds/patients randomized to primary closure and 529 wounds/patients to non- or delayed closure. The meta-analysis demonstrated that there was no statistically significant difference in the incidence of wound infection (38/542, 7.0% versus 40/529, 7.6%; RR Z 0.93, 95% CI, 0.60 to 1.42; P Z 0.72). Studies were of low heterogeneity (I2 Z 0%; P Z 0.74) (Figure 1). Based on the current evidence, though with flaws in research methodology, primary closure for the dog bite wounds would not increase the incidence of wound infection.
Conflict of interest statement There is no potential conflict of interest that exists. No funding was received. All authors have no financial and personal relationships with other people or organisations that could inappropriately influence this work. Ethical approval not required.
http://dx.doi.org/10.1016/j.bjps.2014.05.051 1748-6815/ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Cheng H-T, et al., Does primary closure for dog bite wounds increase the incidence of wound infection? A meta-analysis of randomized controlled trials, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/ 10.1016/j.bjps.2014.05.051
2
Characteristics of included randomized controlled trials comparing primary closure and non or delayed closure for dog bite wounds. No. of patients or wounds randomized
Mean age (range)
Remarkable wound characteristics
Prophylactic antibiotics
Follow-up period
Variables analyzed
Maimaris C et al., 19982
UK
169 wounds (96 patients)
44% of wounds on the hand. 55% of wounds were 1 cm or less
Not given
14 days
Rui-feng C et al., 20134
China
600 patients
N/A (2e83) 60% patients were
