The Science of Hyperbaric Oxygen for Flaps and Grafts.

Hyperbaric oxygen (HBO) therapy is a versatile modality that has applications across several medical fields. HBO therapy has become a valuable asset in the management of compromised tissue grafts and flaps. Although classified together, grafts and flaps are distinctly different, in that grafts depend on the wound bed for revascularization, whereas flaps have an inherent blood supply. Evidence has shown that in a compromised graft suffering from hypoxia, HBO can maximize viability and reduce the need for repeat grafting. By comparison, compromised flaps can suffer from both ischemic and reperfusion injury, which can also be attenuated by HBOT to maximize viability. The beneficial effects of HBO occur by several mechanisms, including hyper-oxygenation, fibroblast proliferation, collagen deposition, angiogenesis, and vasculogenesis. Animal studies have demonstrated several of these mechanisms, including an increase in the number, size, and growth distance of blood vessels after HBO. Likewise, clinical studies have found positive responses in multiple types of tissue grafts and flaps, with some cases involving irradiated fields. Altogether, the data emphasizes that early identification of flap or graft compromise is absolutely critical, with maximized chance for viability when HBO is initiated as soon as possible.