An interventional study of Indocyanine Green Fluorescence Angiography and Standard Surgical Perfusion Assessment in Rectal Cancer Patients, Rectal Cancer Surgery and Colorectal Cancer, sponsored by Basavatarakam Indo American Cancer Hospital & Research Institute. Not yet recruiting at 1 site in India. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-27.
Sponsored by Basavatarakam Indo American Cancer Hospital & Research Institute · Not applicable, Interventional, and Prevention
The goal of this clinical trial is to find out whether using a special green dye called indocyanine green (ICG) during minimally invasive rectal cancer surgery can help surgeons assess blood flow to the bowel and reduce leakage from the surgical connection between two ends of the bowel.
The main questions this study aims to answer are:
Researchers will compare ICG fluorescence-guided assessment with conventional visual assessment of bowel blood flow during rectal cancer surgery.
Participants will:
Anastomotic leakage is a significant complication following rectal cancer surgery. Inadequate blood supply to the bowel ends may contribute to poor anastomotic healing, resulting in postoperative complications and prolonged hospitalization.
Conventional intraoperative assessment of bowel perfusion relies on visual examination of bowel color, bleeding from the cut edges, and pulsation of mesenteric vessels. However, these methods are subjective and may not reliably identify areas of inadequate perfusion.
Indocyanine green fluorescence angiography (ICG-FA) enables real-time visualization of tissue perfusion using near-infrared imaging following intravenous administration of ICG. This technique may help surgeons identify poorly perfused bowel segments before construction of the anastomosis. Previous randomized controlled trials have reported conflicting findings regarding its effectiveness in preventing anastomotic leakage, and evidence from Indian surgical populations remains limited.
The FLARE study is a prospective, randomized, open-label, parallel-group trial comparing ICG fluorescence-guided perfusion assessment with conventional visual assessment during minimally invasive rectal cancer surgery.
In the ICG group, fluorescence imaging will be performed before construction of the anastomosis to assess perfusion at both the proximal large bowel end and the distal rectal stump. If inadequate perfusion is identified, the surgeon may modify the planned bowel transection line to select a better-perfused segment.
In the control group, bowel perfusion will be assessed using conventional visual methods without ICG fluorescence imaging. Both groups will undergo standard rectal cancer surgery and postoperative care.
The study will evaluate whether fluorescence-guided perfusion assessment provides additional clinical benefit compared with conventional visual assessment.
6,541 studies on the registry are indexed under Colorectal Neoplasms; 1,667 are open to participants now.
This study's planned enrollment of 610 is above the median of 76 across 4,800 interventional studies indexed under Colorectal Neoplasms.
Browse Colorectal Neoplasms studies →Basavatarakam Indo American Cancer Hospital & Research Institute is the lead sponsor of 2 studies on the registry; 2 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this group will undergo planned colorectal cancer surgery with standard surgical assessment of bowel blood flow plus indocyanine green fluorescence angiography. Indocyanine green will be given intravenously during surgery, and near-infrared imaging will be used to assess blood flow at the planned bowel joining site. The surgeon may change the bowel transection level if fluorescence suggests poor blood flow.
Diagnostic Test: Indocyanine Green Fluorescence Angiography · Diagnostic Test: Standard Surgical Perfusion Assessment
Participants in this group will undergo planned colorectal cancer surgery with standard surgical assessment of bowel blood flow. The surgeon will assess bowel perfusion using usual clinical methods such as bowel color, bleeding from the cut edge, arterial pulsation, and overall tissue appearance. Indocyanine green fluorescence angiography will not be used.
Diagnostic Test: Standard Surgical Perfusion Assessment
Indocyanine green will be administered intravenously during surgery. Near-infrared fluorescence imaging will be used to assess bowel blood flow at the planned bowel joining site both for proximal large bowel end and distal rectal stump. The surgeon may change the bowel transection level if fluorescence suggests poor blood flow.
Bowel blood flow will be assessed using standard surgical judgment, including bowel color, bleeding from the cut edge, arterial pulsation, and overall tissue appearance.
Total Anastomotic Leakage Rate
Incidence of anastomotic leakage of any grade after surgery. Anastomotic leakage will include grade A, grade B, and grade C leaks. Grade A is a radiological leak without symptoms and without need for active treatment. Grade B is a symptomatic leak requiring non-surgical treatment such as antibiotics or drainage. Grade C is a symptomatic leak requiring reoperation.
Time frame: Within 30 days after surgery
Clinically Significant Anastomotic Leakage Rate
Incidence of clinically significant anastomotic leakage after surgery, defined as grade B or grade C leakage. Grade B leakage is a symptomatic leak requiring non-surgical treatment such as antibiotics, percutaneous drainage, or transanal drainage. Grade C leakage is a symptomatic leak requiring reoperation.
Time frame: Within 30 days after surgery
30-day postoperative morbidity
Number and proportion of participants who develop one or more postoperative complications within 30 days after the index surgical procedure. Postoperative complications will be classified according to the Clavien-Dindo classification. Complications occurring during the index hospitalization or after discharge within the 30-day follow-up period will be included.
Time frame: Within 30 days after surgery
30-day postoperative mortality
Number and proportion of participants who die from any cause within 30 days after surgery. This will include deaths occurring during the index hospitalization as well as deaths occurring after discharge but within 30 days of the surgical procedure.
Time frame: Within 30 days after surgery
Rate of intraoperative modification of the proximal bowel transection line after ICG assessment.
Number and proportion of participants in the ICG-FA group in whom the initially planned proximal bowel transection line is changed after intraoperative ICG fluorescence assessment because of inadequate perfusion. Any modification of the planned proximal transection line following ICG-FA assessment will be recorded.
Time frame: During surgery, after ICG-FA assessment and before construction of the anastomosis
Rate of Intraoperative Modification of the Distal Rectal Stump Transection Line After ICG-FA Assessment
Number and proportion of participants in the ICG-FA group in whom the initially planned distal rectal stump transection line is changed after intraoperative ICG fluorescence assessment because of inadequate perfusion. Any modification of the planned distal transection line following ICG-FA assessment will be recorded.
Time frame: During surgery, after ICG-FA assessment and before construction of the anastomosis
Time to Fluorescence Appearance After ICG Administration
Time, measured in seconds, from intravenous administration of indocyanine green to the first visible appearance of fluorescence at the planned anastomotic site. Fluorescence appearance time will be recorded separately for the proximal large bowel end and the distal rectal stump in participants assigned to the ICG-FA group.
Time frame: During surgery, following ICG administration and before construction of the anastomosis
Operative Time
Total duration of the surgical procedure, measured in minutes from skin incision to completion of skin closure. Operative time will be recorded for participants in both the ICG-FA group and the control group and compared between groups.
Time frame: During surgery
30-Day Reoperation Rate
Number and proportion of participants who require an unplanned surgical reoperation for any postoperative complication within 30 days after the index surgical procedure. Reoperations occurring during the initial hospital admission or after discharge within the 30-day follow-up period will be included. Planned procedures, including elective stoma closure, will not be considered reoperations for this outcome.
Time frame: Within 30 days after surgery
Length of Postoperative Hospital Stay
Duration of postoperative hospitalization, measured in days from the date of the index surgical procedure to the date of hospital discharge. Length of stay will be recorded for participants in both the ICG-FA group and the control group and compared between groups.
Time frame: From surgery until hospital discharge
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No — Individual participant data will not be shared publicly because the study involves surgical patients and contains sensitive clinical information. Public sharing may risk participant privacy and confidentiality, even after de-identification. De-identified aggregate study results will be reported in publications and trial registry results, as required.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Basavatarakam Indo American Cancer Hospital & Research Institute