Flap microcirculation: effects of tissue manipulation and in situ preparation during soft tissue harvest

Microcirculatory disturbances during tissue transfer can lead to tissue damage and decreased flap survival. In this pilot study, we evaluated the influence of pedicle preparation and flap manipulation on the microcirculation of free flaps during harvest. Twenty-eight Sprague Dawley rats were divided into two groups. In group A, microcirculation was investigated before and after in situ preparation of an inferior epigastric flap with dissection of all vascular structures using the orthogonal polarization spectral imaging technique. In group B, the second investigation of microcirculation was performed 20 minutes after skin incision without further manipulations. Group A demonstrated a considerable decline in blood cell velocity, arterial vessel diameter, venous vessel diameter (VVD), and functional capillary density (FCD), whereas group B showed stable values. There was a significant difference between groups for VVD and FCD. Flap manipulation with dissection of the pedicle leads to microcirculatory disturbances. We assume that these microcirculatory disturbances may result in prolonged duration of flap ischemia contributing to an increased failure rate after free tissue transfer.