In case of free flap failure, time is of utmost importance as salvage rates have been reported to be inversely related to the time interval between the onset of ischemia and its clinical recognition. Consecutively, monitoring of free flaps remains of major importance. Currently, combined Laser-Doppler and Spectrophotometry is available to determine microcirculation of free flaps in reconstructive surgery as a scientific method of reliable assessment of flap perfusion. The investigators thought to analyze the correlation of free flap skin temperature and free frap microcirculation as an accurate tool of postoperative flap monitoring.

Inclusion Criteria:

• Age between 16 and 65 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 or equal.

Patients suffering from a soft tissue defect at any location of the body receiving free flap soft-tissue defect coverage at the Department of Plastic, Hand and Reconstructive Surgery, Medical School Hannover, Germany.