Negative Pressure Therapy for Wounds

Negative pressure wound therapy (NPWT) entails application of a homogeneous vacuum to the wound via a sponge. Published studies have described its use in treating urine-induced necrosis, burn injuries, and septic peritonitis, as well as for augmentation of shear injuries and local flaps. Few clinical trials, however, compare NPWT to controls.

This retrospective, multicenter study classified 50 dogs undergoing open-wound treatment into 3 groups: conventional bandage with nonadherent gauze (Group A), NPWT (Group B), and foam dressing (Group C). Pairs of patients were matched between Groups A and C (n = 7 pairs) and Groups B and C (n = 18 pairs) based on wound conformation, localization, and underlying cause. Pairs were compared between the groups in terms of duration of previous treatment, time to closure, and complications.

Signalment, antibiotic use, antiseptic treatment, and bacterial status of wounds were comparable between groups. Duration of previous treatment was significantly higher in Group B than Group C, although no significant difference was seen between Groups A and B. Time to wound closure was significantly shorter in Group B than Group C; time to closure in group C patients was significantly shorter than Group A. Wounds treated with NPWT had significantly fewer complications and were significantly less septic during treatment than wounds treated with foam dressing. This study substantiates the use of NPWT as an effective means of local infection control in wound dressing.

This important retrospective study compares traditional open-wound therapy with NPWT and self-absorbent hydrophilic dressings followed by silver foam dressings in similar wounds of dogs. Reported advantages of NPWT over traditional open-wound bandages include active wound drainage, promotion of granulation tissue formation, reduced infection rates, and shorter wound-closure times. Silver foam dressings offer topical antibacterial efficacy against many antibiotic-resistant organisms, including MRSA in some reports. The fact that NPWT had the shortest time to wound closure and also had fewer infections and complications is not surprising. One comment by the authors—that -100 mm/Hg (vs -125 mm/Hg) reduced leakage—was a valuable tip.

The study supports our experiences that NPWT is an effective therapy, but the need for 24-hour supervision does reduce its versatility. Silver foam dressings, on the other hand, result in faster closure times than traditional bandage techniques and are another good option in most practice settings.—Gary W. Ellison, DVM, MS, DACVS