A New Approach to the Management and Closure of Challenging Tunneling Wounds

Introduction: A tunneling wound or sinus tract is a narrow opening or passageway underneath the skin that can extend in any direction through soft tissue and results in dead space with potential for abscess formation. Also referred to as a tracking wound, these differ from undermining in that they extend in one direction, whereas undermining is destruction of the underlying tissue surrounding the wound margins.

Method: Treatment of tunneling wounds is typically focused on treating the cause of the tunneling. The goal of treatment is to stimulate the growth of granulation tissue in the tract and to make sure that the wound edges do not close prematurely. In extreme cases, it may be necessary to surgically lay open the wound to properly treat the wound.

Results: Intact fish skin graft has been used successfully to achieve these treatment goals. The novel fish skin graft supports the body’s own ability to regenerate by recruiting the body’s own cells. The graft is a decellularized Icelandic codfish skin. Its protein composition closely resembles that of human skin and the porous microstructure provides a scaffold for efficient ingrowth of dermal cells and capillaries. In addition, the graft is uniquely rich in the polyunsaturated omega-3 fatty acids EPA and DHA, which are known for their anti-inflammatory properties that assist in regeneration.

The fish skin graft facilitates significantly more three-dimensional cellular ingrowth than occurs in amnion/chorion tissue. The acellular fish skin is thicker and the microstructure more porous, compared to mammalian matrixes. The unique biochemical properties of the fish skin and the size of its pores facilitate cell ingrowth, a critical step for tissue regeneration.

Conclusion: This case series demonstrates the rapid closure of tracking wounds utilizing the thicker and more porous microstructure to fill deep tracking wounds.