The Use of Indocyanine Green to Visualize Blood Flow to the Gastrojejunostomy During Bariatric Surgery.

The Use of Indocyanine Green to Visualize Blood Flow to the Gastrojejunostomy During Bariatric Surgery

This is an interventional pilot study aimed to evaluate the use of NIF imaging as an intraoperative aid to assess the anastomotic blood flow to the gastric pouch and gastrojejunostomy during Roux-en-Y gastric bypass surgery and to determine its long-term impact on the rate of marginal ulceration, leaks and stricture.

Study Overview

• Status: Active, not recruiting
• Conditions: Obesity, Morbid; Ulcer, Gastric
• Intervention / Treatment: Drug: Indocyanine green; Device: Stryker 1688 AIM system

Detailed Description

The purpose of this study is to examine intraoperative usefulness of near-infrared light fluorescence imaging with a contrast agent called indocyanine green to improve visualization of blood flow to a surgical connection between the small intestine and stomach (gastrojejunostomy) in patients undergoing gastric bypass surgery. ICG will be given prior to and after making the gastrojejunostomy to examine blood flow and then a subjective perfusion score will be given by the surgeon and assistant during the surgery.

Patients will be recruited before the laparoscopic Roux-en-Y gastric bypass surgery and the study data will be collected prospectively through standard bariatric follow up visits up to 2 years. A mid-term analysis of the procedure and patient outcomes will be performed for quality assurance purposes when half the study patients have undergone intraoperative ICG use. The ICG will be not given if a patient is allergic to sodium iodide or has a history of allergy to iodides because of the risk of a severe allergic reaction.

Participants will be assigned an identifying number to protect confidentiality. Descriptive univariate and multivariate statistical analysis will be performed on all patients satisfying the study's inclusion criteria.

• Study Type: Interventional
• Enrollment (Estimated): 300
• Phase: Phase 4

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5T2S8
      • Toronto Western Hospital, University Health Network

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Capacity to provide informed consent.
• Over the Age of 18.
• Eligible for bariatric surgery in Ontario and deemed an appropriate candidate for RYGB surgery by the bariatric program.
• Commit to follow-up within the bariatric program, including behavioral and dietary modifications designed to aid in sustained weight-loss.
• Treatment of marginal ulcer with the revisional surgery.

Exclusion Criteria:

• Not willing to participate in study
• Contraindication to, or not planned to undergo RYGB
• Known allergy to indocyanine green or Sodium Iodide
• Is participant pregnant or planning to get pregnant in next two years
• Ongoing substance abuse or active smoking
• Bleeding diathesis or Coagulopathy
• Unwilling to take PPI medication Post operatively

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Interventional group (with drug); The interventional group will receive indocyanine green during bariatric surgery inside the operating room before and after making the gastrojejunostomy.

Drug: Indocyanine green; Indocyanine green (ICG) is a safe, sterile, water-soluble molecule that binds to plasma proteins and can be injected intravenously. ICG will be injected intravenously based on the patient's weight prior to and after making the GJ anastomosis and a 10 mL bolus of normal saline will be immediately followed the injection of indocyanine green by an anesthesiologist. A subjective score of 1-5 for perfusion will be assigned by operating surgeons. The RYGB will then be completed by the operating surgeon in their routine fashion.; Other Names: SPY AGENT GREEN; Device: Stryker 1688 AIM system; The Stryker 1688 AIM system used during laparoscopic surgery which is sensitive in the visible and infrared spectrum. ICG (SPY AGENT™ GREEN) is used with the SPY mode in the Stryker 1688 AIM fluorescence imaging system to perform intraoperative fluorescence angiography.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The applicability of ICG as an indicator of anastomotic blood flow during bariatric surgery.	ICG imaging will be performed intraoperatively using an existing imaging system (1688 Advanced Imaging Modalities (AIM) System (Stryker)), and the images will be assessed by the operating surgeons and as well as by an independent surgeon (part of the study team, independent from the surgery) postoperatively using a subjective assessment of intraoperative Fluorescence Intensity (FI), a 5-point scale to check blood flow of the stomach and small intestine at the new connection. The scale range is 1 to 5 where a score of 1 signifies no fluorescence signal and poor blood supply whereas a score of 5 signifies maximum fluorescence signal and blood supply. Images will also be analyzed postoperatively to obtain an objective score based on fluorescence intensity. The applicability of ICG imaging in the context of RYGB will be assessed based on the inter-observer agreement.	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The impact of ICG imaging on the rate of marginal ulcer and other complications (leaks, strictures).	The patients in the Toronto Western Hospital as per the standard care of bariatric program will be followed for up to 2 years following surgery to identify any complications including marginal ulcerations. Data is collected prospectively at the study site. The investigator will also use the data from the 5-point scale scoring system reference above to determine the correlation between the scores and the occurrence of marginal ulcers and any other complications (leaks, strictures).	2 years
To evaluate the safety of routine use of NIF imaging using ICG in bariatric patients.	Based on the literature, the investigator does not anticipate intra-operative or injection-related adverse effects. Nevertheless, the investigator will use the existing database that collects postoperative outcomes for 30 days to identify adverse events, if any.	30 days

Collaborators and Investigators

• Sponsor: University Health Network, Toronto
• Collaborators: Stryker Endoscopy
• Investigators: Principal Investigator: Allan Okrainec, University Health Network, Toronto

Study record dates

Study Major Dates

• Study Start (Actual): January 25, 2023
• Primary Completion (Estimated): July 3, 2027
• Study Completion (Estimated): July 3, 2027

Study Registration Dates

• First Submitted: August 9, 2023
• First Submitted That Met QC Criteria: August 9, 2023
• First Posted (Actual): August 21, 2023

Study Record Updates

• Last Update Posted (Estimated): October 16, 2025
• Last Update Submitted That Met QC Criteria: October 14, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Stomach Diseases; Overweight; Obesity; Duodenal Diseases; Peptic Ulcer; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity, Morbid; Stomach Ulcer; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Indoles; Indocyanine Green
• Other Study ID Numbers: 20-5008

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: Yes
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes