Diluted Indocyanine Green Angiography: a Novel Approach to Free Flap Perfusion Evaluation in Reconstructive Microsurgery

Comparing Diluted to Standard Concentration Indocyanine Green Angiography: a Novel Approach to Free Flap Perfusion Evaluation in Reconstructive Microsurgery

The evaluation of perfusion in free flaps is crucial in clinical practice. Currently, the gold standard for evaluation is subjective through clinical assessment. However, indocyanine green angiography (ICGA), a tool that uses a near-infrared (NIR) camera to depict and monitor flap vascularization, offers an objective and reproducible alternative. The population in this study were divided into three equal groups, where each groups were assessed with Indocyanine Green (Aurogreen®, Aurolab, Tamil Nadu, India). The study was conducted with three distinct concentrations of ICGA: 5 mg/mL (100% standard concentration), 2.5 mg/mL (50%), and 0.5 mg/mL (10%). Indocyanine green was given in immediate postoperative manner, after the patient defect has been reconstructed with free flap.

Indocyanine green (ICG) angiography is a novel technique for assessing tissue perfusion. The primary outcome is gray values that being evaluated with IMAGE. Through this study optimal concentration that will show fluorescence in NIR camera can be seen. This is important in order to evaluate free flap perfusion.

This study included 47 patients who underwent free flap surgery. The subjects were consisted of postoperative patient with fibular free flap (FFF), anterolateral thigh flap (ALT), radial forearm free flap (RFFF), and deep inferior epigastric perforator flap (DIEP), with inclusion criteria of this study are individuals who have successfully undergone micro-reconstruction surgery utilizing a viable free flap, with no prior surgical intervention in the area under evaluation, and the donor area for the free flap is devoid of any history of trauma or surgery.

Inclusion Criteria:

• individuals who have successfully undergone micro-reconstruction surgery utilizing a viable free flap, with no prior surgical intervention in the area under evaluation, and the donor area for the free flap is devoid of any history of trauma or surgery. Furthermore, these subjects exhibit an albumin level exceeding 3 g/dL, Haemoglobin more than 10mg/dL, and no complication intraoperative

Exclusion Criteria:

• patients with a history of allergy or hypersensitivity to iodine or ICG, those with renal insufficiency or undergoing routine hemodialysis, and those regularly consuming sodium bisulfites. Additionally, patients with hepatic dysfunction, those regularly taking anticonvulsant drugs, and those experiencing complications during and post-operation are also excluded. Furthermore, patients with psychopathology and/or mental disorders, and those whose transferred free flap has experienced trauma or damage due to external factors during care are not suitable for this study