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

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 8h of injury demonstrated an infection rate of 4.5%, which is lower compared to the 22.2% rate observed in wounds treated later than 8h. 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.