Definition of efficiency in vacuum therapy--a randomised controlled trial comparing with V.A.C. Therapy

Redon drains are still used to suction wounds for vacuum sealing. Vacuum-assisted closure (V.A.C.((R)); Kinetic Concepts Inc, San Antonio, TX) is a computer-controlled therapy system for delivering topical negative pressure therapy. The efficiency of V.A.C. in the treatment of pressure ulcers was prospectively studied in a randomised controlled trial in which patients with pressure ulcers were randomly assigned to negative pressure wound therapy (NPWT) using either V.A.C. or Redon bottles. The target parameters were absolute and relative proportion of wound area consists of granulation tissue, fibrin and necrosis. Other outcome measures were the number of dressing changes and time invested using each system. The study was terminated after a post hoc analysis after inclusion of ten patients because of the significantly better results when using V.A.C., and the substantially larger care effort needed in the Redon group compared with the V.A.C. group. An increase in surface granulation tissue of 54% was observed in the V.A.C. group, and a reduction in the Redon group (P = 0.001). The Redon group showed an increase in fibrin tissue at the wound base of 21.8%, whereas in the V.A.C group, a 27% reduction was observed (P = 0.035). Necrosis was reduced in the V.A.C. group, but this difference did not reach significance. Redon bottles are not a good alternative for V.A.C. therapy for delivering NPWT.