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.

Study Overview

• Status: Completed
• Conditions: Perfusion; Free Flap Evaluation; Indocyanine Green Concentration
• Intervention / Treatment: Diagnostic test: Indocyanine Green

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 47
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Indonesia
  • Jakarta
    • Jakarta Pusat, Jakarta, Indonesia, 10430
      • Faculty of Medicine, Universitas Indonesia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group A (5 mg/mL); This group received 5 mg/mL of ICG or 100% in terms of concentration. The 1 mL of the ICG solution was taken using a 3 mL syringe	Diagnostic test: Indocyanine Green; The patients were split into three different groups, the patient were given ICG with three different concentrations in a double-blind randomized manner postoperatively. The fluorescence emitted was quantitatively analyzed using the ImageJ software to ascertain the mean gray values, providing a robust measure of the ICGA concentration. The imaging was captured using a FLUORO 4000XL type NIR camera, positioned at a distance of 15-20 cm perpendicular to the flap.
Active Comparator: Group B (2,5 mg/mL); This group received 2,5 mg/mL of ICG or 50% in terms of concentration. The 0.5 mL of the ICG solution was mixed with 0.5 mL of distilled water using a 1 cc syringe	Diagnostic test: Indocyanine Green; The patients were split into three different groups, the patient were given ICG with three different concentrations in a double-blind randomized manner postoperatively. The fluorescence emitted was quantitatively analyzed using the ImageJ software to ascertain the mean gray values, providing a robust measure of the ICGA concentration. The imaging was captured using a FLUORO 4000XL type NIR camera, positioned at a distance of 15-20 cm perpendicular to the flap.
Active Comparator: Group C (0,5 mg/mL); This group received 0,5 mg/mL of ICG or 10% in terms of concentration. The 0.1 mL of the ICG solution was mixed with 0.9 mL of distilled water using a 1 cc syringe	Diagnostic test: Indocyanine Green; The patients were split into three different groups, the patient were given ICG with three different concentrations in a double-blind randomized manner postoperatively. The fluorescence emitted was quantitatively analyzed using the ImageJ software to ascertain the mean gray values, providing a robust measure of the ICGA concentration. The imaging was captured using a FLUORO 4000XL type NIR camera, positioned at a distance of 15-20 cm perpendicular to the flap.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gray value of indocyanine green fluorescent	The gray values were seen as the primary outcome to found which concentration has the best fluorescence outcome. NIR Camera, 20 cm above the flap, will assess the fluorescence due to contrast. All groups results are being evaluated with IMAGEJ to produce gray value.	2-5 minutes after the ICG injection

Collaborators and Investigators

• Sponsor: Indonesia University
• Investigators: Principal Investigator: Parintosa Atmodiwirjo, MD, Indonesia University

Study record dates

Study Major Dates

• Study Start (Actual): October 10, 2022
• Primary Completion (Actual): October 10, 2023
• Study Completion (Actual): October 10, 2023

Study Registration Dates

• First Submitted: January 14, 2024
• First Submitted That Met QC Criteria: January 14, 2024
• First Posted (Actual): January 23, 2024

Study Record Updates

• Last Update Posted (Actual): January 23, 2024
• Last Update Submitted That Met QC Criteria: January 14, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: Microsurgery; Free flap; Indocyanine Green Reconstructive
• Other Study ID Numbers: 22-06-0636

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No