Background: In plastic and reconstructive surgery, free flaps are routinely used for treatment of soft tissue defects. Treatment strategies aim at reducing or preventing flap necrosis by conditioning tissue tolerance against ischemia. Although previous studies indicate that remote ischemic preconditioning (RIPC) is a systemic phenomenon, only a few studies have focused on the elucidation of its mechanisms of action. Therefore, the aim of this study is to evaluate the microcirculatory effects of remote ischemic preconditioning on a potential free flap location in a human in-vivo setting for the first time.

Conclusion: Remote ischemic preconditioning improves cutaneous tissue oxygen saturation, arterial capillary blood flow and postcapillary venous flow in a remote free flap donor location. To what extent remote preconditioning might ameliorate the reperfusion injury of free flap transplantation, further clinical trials have to evaluate both in the means of microcirculatory assessment and partial or total flap loss as end points of these studies.

Inclusion Criteria:

• healthy male and female subjects aged 18 to 35 years

Exclusion Criteria:

• soft tissue inflammation or osteomyelitis, peripheral arterial occlusive disease, vasculitis, chronic kidney or liver disease, cardiac dysfunction, arterial hypotension and any type of vasoactive medication, i.e. ß-blockers, calcium channel blockers, nitroglycerin