The influence on wound contraction and fluid evacuation of a rigid disc inserted to protect exposed organs during negative pressure wound therapy

The use of a rigid disc as a barrier between the wound bed and the wound filler during negative pressure wound therapy (NPWT) has been suggested to prevent damage to exposed organs. However, it is important to determine that the effects of NPWT, such as wound contraction and fluid removal, are maintained during treatment despite the use of a barrier. This study was performed to examine the effect of NPWT on wound contraction and fluid evacuation in the presence of a rigid disc. Peripheral wounds were created on the backs of eight pigs. The wounds were filled with foam, and rigid discs of different designs were inserted between the wound bed and the foam. Wound contraction and fluid evacuation were measured after application of continuous NPWT at -80 mmHg. Wound contraction was similar in the presence and the absence of a rigid disc (84 +/- 4% and 83 +/- 3%, respectively, compared with baseline). Furthermore, the rigid disc did not affect wound fluid removal compared with ordinary NPWT (e.g. after 120 seconds, 71 +/- 4 ml was removed in the presence and 73 +/- 3 ml was removed in the absence of a disc). This study shows that a rigid barrier may be placed under the wound filler to protect exposed structures during NPWT without affecting wound contraction and fluid removal, which are two crucial features of NPWT.