Real-Time Assessment of Free Flap Capillary Circulation Using Videocapillaroscopy.

[BACKGROUND] Free tissue transfer is a common method of reconstruction for various surgical defects. Many clinical assessment methods, including flap color monitoring and capillary refill time measurements, are commonly used to assess the microcirculation of the flap, yet there is no objective tool available that can clear real-time visualization of the flap microcirculation. The purpose of this study was to use a novel videocapillaroscope to evaluate the circulation changes on free flap skin surfaces while purposely clamping pedicle vessels.

[METHODS] Ten patients who underwent free flap transfer for head and neck cancer from November of 2019 to June of 2020 were included in the study. Videocapillaroscopic observation was performed after flap elevation, and changes in the flap skin capillary circulation with artery-controlled and vein-controlled clamping were recorded.

[RESULTS] Average total surgery time was 517.91 minutes (SD, 73.3 minutes), average flap elevation time was 102.9 minutes (SD, 18.3 minutes). When the pedicle artery or vein was purposely clamped, the movement of red blood cells in blood vessels stopped; when clamps were removed after 60 seconds, the restoration of red blood cell movements was rapidly observed. When the pedicle artery was clamped, the number of visualizable blood vessels decreased and flap color became relatively white. When the pedicle vein was clamped, the number of visualizable blood vessels increased, and flap color tone had a tendency toward red.

[CONCLUSION] Novel videocapillaroscopy can be utilized for objective real-time flap monitoring by directly visualizing flap skin capillary microcirculation.

[CLINICAL QUESTION/LEVEL OF EVIDENCE] Therapeutic, V.