Noninvasive visualization of the midline-crossing arterial variation in the deep inferior epigastric artery perforator flap using photoacoustic tomography for application in patients with abdominal scars.

[BACKGROUND] The importance of the subcutaneous arterial network crossing the midline in transverse abdominal flaps has been reported. Photoacoustic tomography can be used to noninvasively visualize subcutaneous vascular networks. We applied this novel technology preoperatively in patients undergoing breast reconstruction to detect individual variations in the midline-crossing arteries.

[METHODS] Six patients scheduled to undergo breast reconstruction using free deep inferior epigastric artery perforator flaps were examined. Each scan of the 12 × 8-cm region took approximately 8 min. The accuracy of the tentative artery evaluation defined by photoacoustic tomography was compared with the arterial phase detected by intraoperative indocyanine green angiography. The number of perforator vessels used for the flap, surgical time for flap elevation, and perfusion area ratio were compared with those of the control group.

[RESULTS] The average match rate between tentative artery prediction by photoacoustic tomography and arterial-phase assessment by intraoperative angiography in five patients was 79.8%. Each midline-crossing artery showed individual variations. The photoacoustic tomography group (PAT-1 to 5) showed 1.8 perforators per flap, 163 min for flap elevation, and 93% perfusion area, with no significant differences from the control group (N = 5). A 63-year-old woman (PAT-6) with abdominal scars, including a midline abdominal incision, showed a preserved midline-crossing artery. The planned single perforator deep inferior epigastric perforator flap was successfully applied to the contralateral perfusion area.

[CONCLUSIONS] Photoacoustic tomography noninvasively visualizes the subcutaneous midline-crossing arterial networks. Understanding individual vascular variations can support preoperative planning and surgical indication of abdominal flaps, especially in patients with postsurgical scars.