Elsevier

Injury

Volume 45, Issue 1, January 2014, Pages 237-240
Injury

Primary closure versus non-closure of dog bite wounds. A randomised controlled trial

https://doi.org/10.1016/j.injury.2013.07.010Get rights and content

Abstract

Introduction

Dog bite wounds represent a major health problem. Despite their importance, their management and especially the role of primary closure remain controversial. In this randomised controlled trial, the outcome between primary suturing and non-closure was compared.

Methods

168 consecutive patients with dog bite injuries were included in this study. The wounds were allocated randomly in two treatment approaches: Group 1, consisting of eighty-two patients, had their wound sutured, whilst Group 2, consisting of eighty-six patients, did not have their wounds sutured. All wounds were cleansed using high-pressure irrigation and povidone iodine. All patients received the same type of antibiotic treatment. Our measured outcomes included presence of infection and cosmetic appearance. Cosmetic outcome was evaluated using the Vancouver Scar Scale (VSS). Wound and patient characteristics, such as time of management, wound location and size, and patient age, were recorded and analysed for their potential role in the resulting outcome.

Results

The overall infection rate was 8.3%. No difference in the infection rate between primary suturing and non-suturing group was detected in the present study. The cosmetic appearance of the sutured wounds was significantly better (mean score 1.74) compared to the wounds that were left open (mean score 3.05) (p = 0.0001). The infection rate was comparable among all age groups. Wounds treated within 8 h of injury demonstrated an infection rate of 4.5%, which is lower compared to the 22.2% rate observed in wounds treated later than 8 h. The wounds located at the head and neck exhibited better results in both infection rate and cosmetic outcome. Additionally, wounds >3 cm negatively affected the cosmetic appearance of the outcome.

Conclusions

Primary suturing of wounds caused by dog bites resulted in similar infection rate compared to non-suturing. However, primary suturing exhibited improved cosmetic appearance. Time of management appeared to be critical, as early treatment resulted in lower infection rate and improved cosmetic appearance regardless suturing or not. Furthermore, wounds located at the head and face demonstrated better results.

Introduction

Dog bite wounds represent approximately 60–80% of all animal-related injuries [1], [2]. Considering the fact that these injuries are responsible for approximately 1% of all emergency department visits and that they can be easily complicated, it is surprising that controversy still surrounds certain topics of their management [2], [3], [4]. For example, until recently, there were not well-defined criteria for antibiotic treatment for dog bite wounds management; their treatment was mainly empirical and, therefore, approximately 20% of these injuries was mismanaged [2], [5].

Although the role of suturing in dog bite wounds is well discussed in the literature, several issues remain controversial [6]. Traditionally, it was suggested to leave these wounds open because of the proposed increased risk of wound infection when sutured [6], [7], [8]. However, there are reports indicating that suturing of animal wounds does not necessary increase the incidence of infection [9], [10], [11]. Unfortunately, most of these studies are outdated and performed in different settings; comparisons are thus difficult to make [9], [10]. Additionally, most of the existing evidence focuses on the rate of infection, whilst other important measured outcomes, such as scar formation, are frequently overlooked or evaluated only in the case of facial wounds [4], [12], [13].

The controversy regarding the therapeutic management of dog bite wounds is increasing along with the discovery of new factors that can interfere with the outcome [13], [14]. For instance, location of the wound seems to be a crucial factor. In particular, strong evidence supports suturing of face wounds versus hand wounds, although initially recommendations suggested leaving either wound unsutured [14], [15], [16]. Furthermore, the role of the size of the wound as well as the timing of suturing towards the final outcome has been erratically evaluated, with no consensus present in the literature [17].

The purpose of this study was to evaluate the role of primary suturing in the management of dog bite injuries in comparison to the traditional non-suturing approach. Additional factors that could interfere with the final outcome were assessed. The institutional review board has approved this study and all patients gave their informed consent.

Section snippets

Patients and methods

From 2009 to 2012, 200 consecutive patients with a dog bite injuries were included in the present study. A power analysis determined that a sample of 124 patients would be adequate to demonstrate significance for cosmetic appearance. The aim was to detect with 95% power at 0.05 level of significance a difference of 1.30 between the groups. This difference was based on the findings of a pilot study that also determined a standard deviation (SD) of 1.42 and 2.34 for each group respectively. To

Results

During assessment, 18 patients were excluded from our analysis and 14 patients were lost in the follow up (Fig. 1), leaving 168 patients to be included in our analysis. Eighty-two patients had their wounds sutured (group 1) and in eighty-six patients, the wounds were left open (group 2). The topography of the wounds, as well as the different characteristics in the two groups, are shown in Table 2.

The infection rate in our study was 8.3% (Table 3). Eight patients belonging to the primary

Discussion

The present study compared primary suturing of dog bite wounds with non-suturing in a randomised controlled trial. There is currently no consensus in the literature regarding the need for primary suturing in animal related wounds. Traditionally, most studies suggest primary suturing of a wound only when it is located to the head and face, whilst all other wounds are suggested to be left open [4], [7], [8], [14]. To our knowledge, there is only one prospective randomised trial that has evaluated

Conclusions

Primary suturing of dog bite wounds when associated with debridement, high pressure irrigation, povidine iodine cleansing and antibiotic administration resulted in improved cosmetic appearance with no significant increase in the rate of infection. A non-suturing approach was found to be less successful in regards to scar formation. According to this study, one of the most important factors contributing to the outcome was the timing of the management, with early treatment (<8 h) resulting in

Conflict of interest statement

The authors declare no conflict of interest in the preparation and presentation of this article.

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