9 - Negative pressure dressings in venous ulcers

Abstract

This chapter discusses the negative pressure dressing in venous ulcers. One of the newer modalities in managing both acute and chronic wounds is the use of topical negative pressure dressings. The topical negative pressure dressing in its most common form consists of an open cell polyurethane sponge with 400–600 μm pores, a transparent adhesive covering, noncollapsible tubing, and a vacuum-generating device with a collection reservoir. The device has a set of extensive controls that will maintain a wide range of negative pressure settings and is capable of maintaining continuous or intermittent suction. The topical negative pressure dressing can enhance many of these stages, which are needed for the wound healing process to occur. The exact mechanism by which topical negative pressure dressings lead to improvement in wound healing is unknown, but several theories have been presented. The topical negative pressure dressing decreases local edema, results in an increase in local blood flow, may decrease wound's bacterial burden, and causes mechanical deformation of the wound bed, leading to improved wound healing. It also decreases chronic wound fluid and contributes to the maintenance of the moist wound-healing environment, which is necessary for wound healing. All of these effects promote an increase in cell division and proliferation, an increase in matrix synthesis, and an increase in wound protein synthesis.