Studying Deep Inferior Epigastric Perforator Flap Perfusion Using the Isolated-perfused Human Abdominal Skin Flap.

[BACKGROUND] This study investigated dynamic deep inferior epigastric artery perforator flap perfusion in an ex vivo perfusion model using dynamic infrared thermography (DIRT) and indocyanine green fluorescence angiography (ICG-FA) and compared the results with static perfusion imaging using color dye injection technique and computed tomography angiography (CTA).

[METHODS] Individual vessels were perfused with modified Krebs-Henseleit buffer (pH 7.4) in an isolated-perfused human abdominal skin flap perfusion model. Their perfusion patterns were sequentially evaluated with all 4 imaging techniques.

[RESULTS] Perfusion patterns of 37 vessels in 19 hemi-deep inferior epigastric perforator (DIEP) flaps and 1 cross-midline DIEP flap were examined. DIRT and ICG-FA measurements of perforators displayed similar perfusion patterns and corresponded well with the colored skin area after dye injection. CTA showed equivalent 3-dimensional images of the selected perforator. Lateral and medial perforators had variable perfusion patterns but often drained into the superficial veins; and sometimes perfused both the medial and lateral flap zones. CTA revealed true anastomosis connecting 2 different perforators, whereas the other imaging modalities showed a large overlap on the skin. DIRT showed that the venous drainage can be rerouted between the ipsilateral and contralateral superficial inferior epigastric vein when 1 superficial inferior epigastric vein is obstructed in the cross-midline DIEP flap.

[CONCLUSIONS] DIRT and ICG-FA provided comparable and reproducible results that could easily be related to the skin perfusion area in the color dye experiments and CTA 3-dimensional reconstruction, supporting the use of DIRT and ICG-FA for evaluating and investigating DIEP flap perfusion in clinical and research settings.