CompletedInterventional

The extent of intimal hyperplasia and atherogenesis in bypass vein grafts following different surgical preparation techniques

Coronary artery bypass surgery helps restore healthy blood flow to your heart, often using a healthy vein taken from your leg. However, up to 40% of these vein grafts become narrowed or blocked over 12 years. If a graft closes, chest pain and other heart problems can return. Surgeons usually clear away the fat around the vein and test it for leaks under high pressure. Researchers want to know if preparing the vein more gently—either by leaving a layer of protective fat or by checking for leaks using lower fluid pressure—stops the vein wall from being damaged. This study tests four different preparation methods in patients having bypass surgery at the Bristol Royal Infirmary. Participants have their operation as planned, followed by special heart checks one year later to see how open and healthy the veins remain.

At a glance

Status

Completed

Sponsor

University Hospitals Bristol NHS Foundation Trust (UK)

Enrolment target

Start

01 Aug 2009

Estimated completion

01 Jul 2015

Coronary artery disease

What is this study about?

When the blood vessels supplying your heart muscle become narrowed by fatty deposits, doctors may recommend a coronary artery bypass graft (CABG). During this operation, surgeons take a healthy blood vessel from another part of your body—often the long vein in your leg—and use it to route blood around the blockage. While this operation is very successful, the leg veins used as grafts can slowly narrow and become blocked over the years. Finding ways to protect these veins during surgery is vital to keeping them working well for as long as possible.

Currently, surgeons usually strip the fat off the leg vein before sewing it into place. They also inject fluid into the vein under high pressure to check for leaks. Researchers believe this standard process might accidentally stretch or injure the vein wall, causing it to thicken and clog up sooner. This study is testing whether leaving the surrounding fat in place to protect the vein, or using a gentler low-pressure test for leaks, keeps the vein healthier.

Patients taking part are placed by chance into one of four surgical groups testing combinations of these methods. One year after surgery, doctors will check the veins using detailed scans to measure their thickness and blood flow. The findings will help surgeons across the NHS understand the best way to handle veins during bypass surgery in the future.

Key takeaways

Compares four different ways surgeons remove and test leg veins used in heart bypass surgery.
Aims to discover if gentler handling prevents bypass veins from narrowing or blocking over time.
Open to adults having their first planned bypass operation at Bristol Royal Infirmary.
Includes a detailed follow-up scan (angiogram and ultrasound) 12 months after your surgery.
Participation is entirely voluntary and will not alter your main heart operation.

Who may be eligible?

You may be able to join this study if you are 18 or older and are scheduled to have your first planned (elective) heart bypass operation at the Bristol Royal Infirmary, where the surgical team plans to use at least one vein from your leg.

You will not be able to take part if you need emergency bypass surgery, or if you need another procedure at the same time, such as heart valve repair. People who have had heart surgery in the past are also excluded.

Doctors will also check that your heart pump strength is safe for the study, and that you do not have severe heart failure, serious circulation problems in your legs, kidney disease, or a known allergy to the iodine dye used in X-ray heart scans.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am aged 18 or over.
I am having my first planned heart bypass operation at Bristol Royal Infirmary.
My surgical team plans to use a vein taken from my leg.
I do not need emergency surgery or a heart valve replacement.
I do not have severe kidney problems, leg circulation issues, or an allergy to X-ray contrast dye.

Answer every question to see your result.

What does participation involve?

If you take part, your bypass surgery will go ahead as planned at the Bristol Royal Infirmary. A computer will randomly assign you to have your leg vein prepared using one of four surgical techniques. You will receive standard post-surgery hospital care and follow-up. One year after your operation, you will return to the hospital for a detailed assessment of your bypass grafts. This involves an angiogram (an X-ray test using a special dye injected into your blood vessels) alongside an intravascular ultrasound, which uses sound waves inside the vein to measure its wall thickness. This combined scan takes around 30 to 40 minutes. Your total involvement in the study lasts for about one year.

Potential risks and benefits

Taking part may give you a gentler surgical technique that could help keep your bypass vein open and healthy for longer, though this cannot be guaranteed. Your participation will also help improve surgical methods for future heart patients. The main risks involve the leg wound: previous work showed that leaving fat on the vein might slightly raise the risk of a wound infection (from 5% up to 10%) or cause temporary skin numbness. The one-year heart scan uses X-rays, carrying a radiation dose similar to about five years of natural background radiation, and involves a tiny risk (less than 1 in 1,000) of serious complications like bleeding, heart attack, or stroke. Taking part is completely voluntary, and you are free to leave the study at any time without your regular NHS medical care being affected.

Locations (1)

Bristol Heart Institute
Approximate
Bristol, England

Common questions

Will taking part delay my bypass surgery?

No. Your operation will take place at its planned time. The study only changes how the surgeon prepares your leg vein during the procedure.

Can I choose which preparation technique the surgeon uses?

No. A computer assigns you to one of the four methods at random. This makes sure the trial is fair and the medical results are reliable.

Will the one-year follow-up test hurt?

The angiogram and ultrasound test use local anaesthetic where the small tube is placed, usually in your wrist or groin. You may feel a brief warm flush from the dye or slight pressure, but it is generally well tolerated.

Will my leg look different after this operation?

You will have a standard surgical cut on your leg where the vein is taken. The scar should look similar regardless of which method is used, although there is a small chance of numbness around the area.

What happens if I decide to withdraw from the study?

You can leave the study at any point. Your decision will not change your relationship with your surgical team or affect the quality of your care.

How to find out more

Gianni Angelini

Official trial record

Always speak to your GP or specialist before deciding to take part in a study.