Comparison of Antibacterial Efficiacy of Standard Negative Pressure Wound Therapy (NPWT) and Negative Pressure Wound Therapy with Instillation (NPWTi) in the Dog

Introduction:
A combination of negative pressure wound therapy and instillation has been developed in order to address bacterial bio-burden during open wound treatment in humans. Despite the published potential of this method, there are currently no studies available that validate the effect in dogs.

Material and Methods:
A total of 19 client-owned dogs were evaluated in a prospective clinical trial and divided into two groups: Negative Pressure Wound Therapy (NPWT) (Group A , n=10) or Negative Pressure Wound Therapy with instillation of polyhexanide (NPWTi) (Group B, n=9). Bacterial culture results were assessed at day 0, 6 and 9 of wound treatment. The effect of therapy on wound bio-burden reduction was compared as well as the effect on general wound healing and patient data.

Results:
A moderate to high effect (Cohan d 0.79) was detected in favor of Group B with respect to reduction of bacterial number. However, this was not significant. The reduction of bacteria species in the wounds (mean 1-1-1 Group A; 1-1- 0.5 Group B) and the total number of wounds that became negative under treatment (1/10 Group A, 4/9 Group B) was also higher in Group B, but again this was not significant.

Discussion/Conclusion:
NPWTi might offer an effective local antibacterial treatment option in open wounds, however further studies are needed to validate this effect.