A study looking to reduce a serious side effect of rectal cancer surgery (IntAct)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Bowel (colorectal) cancer
Rectal cancer





A serious side effect of rectal cancer surgery is a leak from where 2 bits of bowel have been joined. This is called an anastomotic leak. This study wants to see if a new technology can help reduce this.

More about this trial

The main treatment for rectal cancer is surgery. During the surgery, the surgeon removes the piece of bowel which contains the cancer and joins the bowel back together. This join is called anastomosis.

A serious side effect of this surgery is a leak from where the 2 parts of bowel have been joined. This is called an anastomotic leak. It develops when the join in the bowel doesn’t heal properly after surgery. This can cause long term side effects.

These long term side effects include:

  • a decrease in quality of life
  • further wound problems
  • a permanent stoma
  • cancer recurrence

The researchers think that one possible cause of an anastomotic leak is that the blood supply is poor in the join of the bowel after surgery.

The study team want to look at reducing this side effect. They want to use a new technology called Intraoperative Fluorescence Angiography (IFA) during the operation. This is a dye which is injected into the blood and makes it glow. It shows the surgeons the blood supply around the join which can help them make decisions during the operation.

They also want to look into the:

  • bacteria within the bowel
  • blood supply to the bowel

Who can enter

The following bullet points list the entry conditions for this study. Talk to your doctor or the study team if you are unsure about any of these. They will be able to advise you.

Who can take part
You may be able to join this study if all of the following apply. You:

  • have rectal cancer which needs an operation to remove it
  • can have keyhole (laparoscopic) or robotic surgery
  • are well enough to take part in the trial
  • are at least 18 years old

Who can’t take part
You cannot join this study if any of these apply. You:

  • are not having an anastomosis to rejoin your bowel – you are having a stoma
  • have advanced rectal cancer which requires surgery to remove another part of the bowel in addition to the rectum
  • have advanced rectal cancer which requires surgery to remove other organs in addition to the rectum
  • have recurrent rectal cancer
  • have a problem with how your immune system Open a glossary item works. This might be because you are having steroids or an immunotherapy Open a glossary item
  • have any serious medical conditions that the trial team thinks can affect you from taking part in this trial
  • have any other medical problems with your colon or rectum such as another cancer or bowel disease
  • have had any previous radiotherapy to the pelvis which is not to do with rectal cancer
  • have liver disease
  • have kidney disease
  • are allergic to the contrast used in this study
  • are pregnant or likely to become pregnant within 3 months of having the surgery

Trial design

The study team want to recruit 880 people across Europe. It is randomised. The people taking part are put into 1 of 2 groups at random. Neither you nor your doctor will be able to decide which group you are in.

  • One group has surgery without IFA
  • The other group has surgery with IFA

Both groups have a contrast enema around 4 to 6 weeks after the operation.

IntAct diagram

There are 2 sub studies in this trial which look into more detail as to why some people have an anastomotic leak and others don’t.

Microbiome sub study
This is for the first 200 people who are recruited in the UK for either group. The study team look at the bacteria within the rectum. To do this, they take a poo (stool) sample before, during and 3 to 5 days after the operation from within the bowel.

To collect the sample a doctor will use a special camera called a proctoscope. They put this into your back passage and collect a small sample of poo. It takes about 1 minute and should not cause any pain.

Perfusion sub study
This is for 75 people who are already taking part in this trial. Everyone must be having treatment at a UK hospital and having surgery with IFA. It is optional so you can say whether you would like to take part or not.

The study team look at the blood supply which goes to the bowel in more detail. For this you have CT scans before your operation

Hospital visits

You see the doctor and have some tests before you can take part in the study. The tests include:

  • a physical examination
  • blood tests
  • CT scan
  • MRI scan
  • colonoscopy
  • fitness assessment

If you are part of the perfusion sub study then you have two additional specialised CT scans.

If you are part of the microbiome sub study, a doctor will take a poo sample from you before, during and 3 to 5 days after the operation.

Follow up
Everyone taking part has a contrast enema scan 4 to 6 weeks after their operation.

The trial team will ask you to fill out a questionnaire before your operation and 30 and 90 days after your operation. They take about 20 to 30 minutes each time. The questionnaire will ask about side effects and how you have been feeling. This is called a quality of life study. There may be another questionnaire 1 year after the operation.

30 days and 90 days after your operation you will have a follow up appointment to see how you are.

Side effects

The possible side effects are the same as any rectal cancer surgery and include:

  • damage to the organs around the rectum, which can include the bladder, bowel and nerves
  • an infection
  • bleeding
  • breathing problems
  • a permanent stoma
  • urine infection
  • risk of stroke
  • blood clots in the legs
  • wound infection
  • hernia
  • risk of heart problems such as heart attack
  • back pain
  • pressure sores
  • inflammation of the gallbladder
  • inflammation of the pancreas
  • confusion
  • allergic reaction to the contrast which can include flushing of the skin, itchy skin, skin rash and difficulty breathing

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor David Jayne

Supported by

NIHR Efficacy and Mechanism Evaluation (EME) Programme
University of Leeds

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Cara took part in a clinical trial

A picture of Cara

"I am glad that taking part in a trial might help others on their own cancer journey.”

Last reviewed:

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