Objective: The key to the success of pedicled skin flaps in the head and neck region is preserved perfusion. The use of thermal imaging can provide an indirect indicator of tissue perfusion, which consecutively would be of interest for perioperative prediction of the viability. The effectiveness of thermal imaging has already been demonstrated for assessing pedicled and free flaps [1]. This work investigates the implementation of SBTI as a noninvasive and cost-efficient method in clinical practice for predicting the vitality and perioperative monitoring of pedicled skin flaps in head and neck surgery.
Methods: The FLIR One Pro camera was used for this pilot study (Teledyne FLIR LLC, Wilsonville, Oregon, United States). It is a multispectral camera that contains a near-infrared camera unit with a resolution of 160 x 120 pixels, a temperature range of 0 ° - 400 °C, and a thermal resolution of 70 millikelvin. For the study, after implementing the system, n = 11 skin flaps were photographed by SBTI (n=44) after marking (T1), after elevation (T2), after completed surgery (T3), and 24 hours postoperatively (T4), and the outcome was assessed clinically in correlation after one week by one surgeon.
Results: The pedicled skin flaps examined all showed a preserved, uniform thermal image signature peri- and postoperatively for time points T1-4. This corresponded to a good postoperative result regarding the vitality of the tissue transfer in the clinical assessments 24 hours and one week postoperatively.
Conclusion: The acquisition of a continuously obtained thermal image signature as a surrogate marker for preserved tissue perfusion by SBTI proved simple, inexpensive, noninvasive, and efficient in the present sentinel study. The application of SBTI has been primarily investigated in identifying perforators in large pedicled or free flaps. [2, 3] The concordance of the obtained thermal image signature with a positive clinical outcome suggests that the presented method is also suitable for perioperative prognostic statements on postoperative flap vitality in pedicled skin flaps and for monitoring those during surgery. Further studies are necessary for the implementation of this method in clinical practice to support the surgeon's intraoperative decision-making in the future.