Perfusion dynamics of the medial sural artery perforator (MSAP) flap in lower extremity reconstruction using laser Doppler perfusion imaging (LDPI): a clinical study.

Perforator flaps are a mainstay in reconstructive surgical practice but are limited by complications, including flap failure, resulting from flap hypoperfusion. This study aimed to characterize the early post-operative perfusion dynamics of the medial sural artery perforator (MSAP) flap in lower extremity reconstruction using laser Doppler perfusion imaging (LDPI). 12 patients, recruited between 2014 and 2015, with lower extremity reconstructions using free MSAP flaps were assessed for perfusion using a hand-held colour Doppler ultrasound device on days 1, 3, and 5 post-operatively. Perfusion at four distinct zones was assessed; whole flap, control zone, perforator zone, and distal zone, by a single operator using a standardized technique. The perforator zone was noted to have the highest relative perfusion of all zones measured across all post-operative days, and this was correlated with whole flap perfusion ( r =  0.82, p  = 0.002). No significant perfusion differences were found within any of the zones over the 5-day period. The perfusion at the distal zone was not found to correlate with either the perforator zone perfusion, flap length, flap length to width ratio or smoking status ( p  > 0.05). Perfusion of the MSAP flap can adequately be monitored using LDPI at any point throughout the flap, though is highest at the perforator zone, and remains constant in the early post-operative period.