Objectives:
Chronic wounds pose a major challange in plastic and reconstructive surgery. Suction devices to increase the healing process have been largely utilized over the last decades with the use of several different interfaces. In this study we concentrate on the importance of the wound interfaces in suction devices.
Methods:
A full-thickness wound model in a diabetic mouse was treated with several different interfaces: a polyurethane foam without and with downward compression of approximately 125 mmHg, the complete VAC device with or without a silicone interface. The effects of the treatment modes on the wound surface were quantified by a two-dimensional immunohistochemical staging system based on angiogenesis, as defined by blood vessel density (CD31) and cell proliferation (defined by ki67 positivity), 7 days after wounding. Granulation tissue formation was compared among the groups. Wound surface deformation was evaluated under dressing modes of in situ fixed tissues.
Results:
The Vacuum Assisted Closure device induces significant wound strains (60%) causing a single cell deformation, leading to a profound upregulation of cell proliferation (4-fold) and angiogenisis (2·2-fold) compared to wounds treated withoud an interface. Polyurethane foam exposure causes a rather unspecific angiogenic response without changes of the cell proliferation rate of the wound bed. A perforated silicone interface caused a significant lower microdeformation of the wound bed correlating to limited stimulation of the wound tissues.
Conclusion:
The three dimensional foam compressed onto the wound bed under suction causes profound microdefomation that stimulates tissue growth by angiogesis and cell proliferation. The polyurethane foam wound interface is crucial to induce healing while silicone interfaces inhibit granulation tissue formation in this woundmodel. Further investigations on suction devices should concentrate on the design of interfaces.