Lower extremity reconstruction: utility of smartphone thermal imaging camera in planning perforator based pedicled flaps

Abstract

Background: Presence of good size perforators are mandatory to design perforator based pedicelledflaps specially in lower limb as flap failure rate isrelativelyhigh. We have explored the use ofsmartphonebaseddynamic thermal imagingand compared it with doppler to devise a protocol forplanning and executionof pedicled perforator flaps anddescribedits use in deciding delay of flap. We have also compared the time required for detecting dominant perforators.

Methods: This prospective case series was done atJinnah burn and reconstructive surgery center Lahore from July to September 2018and included patients requiring pedicled fasciocutaneous or musculocutaneous flapfor lower extremity reconstruction. Smartphonebased dynamic thermal imaging and doppler wereused to map out suitable perforators and confirmed intraoperatively. Comparison was made regarding their ability to locatedominant perforatorsandtotal time required.Utility of thermal imaging to ascertain flap perfusion postoperatively was also assessed.Flaps were designed according to thermal mapping. Clinical judgement supplemented with thermal imaging was usedto ascertain flap survival.

Results: The study included 15 patientsin which22 out 23 dominant perforators as located withthermal imaging were confirmed intra-operatively (positive predictive value = 95.7%) as compared to 22 out of 32 with doppler(positive predictive value=68.8%). Mean time required with doppler was 591.27±252.48, compared to 598.47±192.94 seconds with thermal imaging. In two cases flap was delayed. Partial flap necrosis occurred in one case.

Conclusion: Dynamic thermal imaging can be reliably usedin planning of pedicled perforator flaps for lower limb reconstruction. We have found itmore reliable than handhelddoppler in locating dominant perforators.

Keywords: Dynamic Thermal Imaging;Perforator Based Flaps; Lower Extremity Reconstruction.