The Fate of Sensation in Noninnervated Perforator Free Flaps in the Lower Extremity.

Background: The recovery of sensation for noninnervated perforator flaps is not well understood. This prospective study aims to evaluate the quality, tendency, and related factors for recovery of sensation.

Methods: A total of 187 patients over a 6-year period were evaluated at intervals of 3, 6, 12, and +24 months for demographic data and sensory tests [Semmes-Weinstein (SW) monofilament test, static two-point discrimination, temperature, and pain] on peripheral and central regions of the flap. Further detailed assessment using the SW monofilament test was made according to flap thickness, size, type, and recipient sites. Factors correlated to poor recovery were evaluated.

Results: Among the flaps tested, the 5.07 SW monofilament test revealed that the peripheral flap sensory recovery was achieved in 72% at +24 months with a significantly increasing linear trend ( P < 0.001). However, the central recovery was noted in only 26% to 28%. The two-point discrimination was achieved in 21% without a significant trend, whereas temperature and pain showed significant improvement, achieving 49% and 64% on the peripheral region and 22% and 31% for the central region, respectively. The flap thickness, size, type, and recipient sites did not exert significance. Only smoking was a significant factor, with 13 times higher odds of hindering sensory recovery.

Conclusions: The SW monofilament test, temperature, and pain sensation on the periphery of the flap showed increasing trend of recovery over the +24 months. Among the various factors, only smoking attenuated recovery. Understanding the fate of sensory recovery in noninnervated perforator flaps will allow the surgeons to further customize the reconstruction based on the defect and maximize efficiency.

Clinical Question/level Of Evidence: Risk, III.