Application of intraoperative indocyanine green angiography for detecting flap congestion in the use of free deep inferior epigastric perforator flaps for breast reconstruction

Background: The use of intraoperative indocyanine green (ICG) angiography has been well documented for confirmation of arterial perfusion in transferred free flaps. However, no previous report has yet focused on whether ICG angiography can be used to detect congestion in free flaps. The present report investigates the feasibility of ICG angiography for detecting flap congestion intraoperatively through illustrative cases. Methods: From September 2019 to September 2020, 65 consecutive female patients who underwent breast reconstructions using a free deep inferior epigastric perforator (DIEP) flap were enrolled in this study. Forty-eight patients with 52 DIEP flaps were eligible for the study after application of the exclusion criteria. ICG angiography was performed after elevation of the flap, after completion of the anastomoses, and after inset of the flap. Results: In five cases (9.6%), an inadequate highlight was demonstrated with ICG angiography performed after flap elevation. All such cases were deemed congestive since robust bleeding was observed with the prick test. ICG angiography demonstrated sufficient highlight of the flap after removal of the clamp on the superficial inferior epigastric vein. In two cases (4.2%), kinking of the pedicle vein of the DIEP flap was found with ICG angiography performed after inset of the flap. In both cases, the pedicle and the flap were reinset. All flaps survived completely postoperatively. Conclusion: ICG angiography can detect flap congestion, and the proposed 3-step protocol is useful for the prevention of postoperative complications.