Efficacy of Intraoperative Indocyanine Green Fluorescence Imaging in Determining the Cutoff Area in Pedicled Transverse Rectus Abdominis Myocutaneous Flap (ICT Study).

Background: The circulation of the pedicled transverse rectus abdominis myocutaneous (TRAM) flap is often poor in zone IV, which is usually excised. Indocyanine green (ICG) dye analysis is a modality that can help surgeons predict and remove insufficient tissue perfusion areas. This retrospective study (ICT study) compared clinical flap outcomes following pedicled TRAM flap reconstruction with or without ICG fluorescence imaging. Methods: Patients who underwent pedicled TRAM flap reconstruction from January 2003 to March 2024 were included. In cases using ICG guidance, the boundary of zone IV was identified and separated according to the ICG enhancement. Results: A total of 301 patients were studied, with 254 in the non-ICG group and 47 in the ICG group. The overall flap complication rate was 22.9%. In the non-ICG group, we found 61 in total, of which 40 had mild fat necrosis, 19 had severe fat necrosis, 1 had partial flap loss, and another had complete flap loss. In the ICG group, among 8 patients with complications, 4 had mild fat necrosis and 4 had severe fat necrosis, and no flap losses occurred. There was no significant difference between the groups. Complications were associated with a BMI over 25 and postoperative radiation. In 8 patients (17%), using ICG allowed more of the zone IV area to be preserved, but did not significantly affect flap complications. Conclusions: ICG fluorescence imaging is not significantly different from an anatomy-based technique in pedicled TRAM flap reconstruction, but it still helps surgeons to identify insufficient perfusion areas, leading to a lower incidence of flap complications. High BMI and postoperative radiation are related to flap complications.