Indocyanine Green Fluorescence Angiography (ICG-FA) in Revisional Bariatric Surgery

Instituto Mexicano del Seguro Social108 enrolled

Overview

This study will compare different doses of a green fluorescent product that is administered during weight loss surgery in order to observe where blood vessels are located. There is uncertainty around the optimal dose of this product for patients with obesity, so this study will aim to study if the dose in the minimal range recommended by international guidelines is sufficient for most patients or if higher doses are needed with increasing body mass index.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

QUADRUPLE

Enrollment

108

Conditions

Obesity Bariatric Surgery

Interventions

Three different doses of indocyanin green will be compared (5 mg, 7.5 mg, and 10 mg). These doses are within the range of currently recommended doses by the International Society for Fluorescence Guided Surgery (ISFGS) for bariatric surgery.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Diagnosis of obesity with a BMI ≥ 30 kg/m² * Scheduled for revisional bariatric surgery Exclusion Criteria: * Allergy to iodides. * Anticoagulation with products containing sodium bisulfite (due to the risk of ICG-FA inactivation). * Use of radioactive iodine studies within the past 7 days. * Pregnant, breastfeeding, or planning to become pregnant within the next year (due to unknown teratogenic or fertility effects of ICG-FA). * History of liver disease or laboratory findings suggestive of moderate to severe hepatic disease: total bilirubin \>1.5 times the upper limit of normal (ULN), or any elevation of aspartate aminotransferase (AST) above ULN. * Participants who withdraw their consent to participate in the study (elimination criterion).

Outcomes

Primary Outcomes

Time to Fluorescence Detection

Time (in seconds) from intravenous injection of indocyanine green (ICG) to the first visual detection of fluorescence in the surgical field, as captured using near-infrared fluorescence imaging. Assessed at four time points (30s, 60s, 90s, 120s) post-injection. Timing will be standardized from injection to image capture. Time point of first visible fluorescence will be recorded by blinded assessors.

Time frame: Intraoperative (within 5 minutes post-injection)

Secondary Outcomes

Regional Tissue Perfusion by Anatomical Zone

Fluorescence signal intensity and timing will be recorded for predefined anatomical zones based on vascular supply in the gastric pouch and duodenal stump. Zones are classified as Zone 1 (proximal/cardial), Zone 2 (mid/corporal), Zone 3 (distal/anastomotic) for the pouch, and Zone 1 (pyloric transition), Zone 2 (suprapancreatic duodenum), and Zone 3 (distal duodenum) for the duodenum. Signal quality will be scored (e.g., adequate/inadequate) and recorded for each zone.

Time frame: Intraoperative

Change in Surgical Strategy Based on ICG-FA

Proportion of cases in which surgical plans were modified intraoperatively (e.g., change in site of anastomosis, reinforcement, or tissue resection) based on ICG perfusion findings.

Time frame: Intraoperative

Adverse Events Related to ICG Use

Number and type of adverse events related to ICG administration, including allergic reactions (e.g., rash, anaphylaxis) or abnormal elevations in liver enzymes (AST, ALT, bilirubin) postoperatively.

Time frame: Within 48 hours postoperatively

Postoperative Complications

Incidence of postoperative complications within 30 days, including anastomotic leak, infection, bleeding, reoperation, or readmission.

Time frame: 30 days postoperatively