Rare Indocyanine-Induced Anaphylactic Shock During Deep Inferior Epigastric Artery Perforator Breast Reconstruction: A Case Report.

Indocyanine green (ICG) is a water-soluble green substance that is detectable through infrared cameras and emits greenish light. Approved for medical use in the 1950s, ICG has gained prominence as a real-time visualization tool. Widely recognized as a generally safe substance, ICG is applied in diverse fields. Despite its prevalent use without significant safety concerns, we report a case of anaphylactic shock due to ICG to reflect on its potential risk.A 46-year-old woman with phyllodes tumor of the breast came to our clinic. She had no significant medical history except dog hair allergy. She underwent nipple-sparing mastectomy, and we planned reconstruction with a deep inferior epigastric perforator free flap. Intraoperatively, we injected ICG to visualize the perfusion area of the abdominal flap. Immediately after injection, her blood pressure dropped to 39/32 from 124/66. Anaphylaxis management included injection of epinephrine, norepinephrine, and steroid. With proper management, her vital signs recovered to normal ranges and the operation proceeded. After discharge, the patient developed no flap-related or internal medical complications.Despite the widely known safety of ICG, it carries a risk of life-threatening adverse effects. Surgeons should be aware that, although rare, these events can occur in their operations.