Perfusion Controlled Mobilization after Lower Extremity Free Flaps-Pushing the Limits of Time and Intensity.

The current standard to gradually adapt the fragile perfusion in lower extremity free flaps to an upright posture is the dangling maneuver. This type of flap training neither fits the orthostatic target load of an upright posture, nor does it assist in mobilizing the patients effectively. In this study, we quantitatively analyzed training effects of an early and full mobilization on flap perfusion.  A total of 15 patients with gracilis flaps for distal lower extremity reconstruction were included. Flap training was performed daily by mobilizing the patients on a tilt table into a fully upright posture for 5 minutes between the third and fifth postop days (PODs). Changes in micro- and macrocirculation were analyzed by laser Doppler flowmetry, remission spectroscopy, and an implanted Doppler probe.  All flaps healed without complications. Yet, in three patients, the increased orthostatic load required an adjustment of the training duration due to a critical blood flow. The others showed an increasing compensation in the microcirculation. When tilting the patients, blood flow and oxygen saturation dropped significantly less on POD5 than on POD3. Furthermore, a significant increase of the blood flow was noted after an initial decrease during the mobilization on all days. An increasing compensation in the macrocirculation could not be determined.  Full mobilization of patients with lower extremity free flaps can be performed safely under perfusion monitoring, already starting on POD3. Additionally, monitoring allows a consideration of the individual orthostatic competence and therefore, exploitation of the maximum mobilization potential.