What veins or arteries are used for grafts? 

In coronary artery bypass graft (CABG) surgery, surgeons use healthy blood vessels taken from other parts of the body to bypass blocked heart arteries. These vessels, known as grafts, act as new pathways for oxygen rich blood to reach the heart muscle. The choice of which vein or artery to use is a critical clinical decision based on the location of the blockage, the patient’s age, and the quality of the available vessels. 

In this article, you will learn about the most common sources for grafts, including the internal mammary artery, the saphenous vein, and the radial artery. We will also discuss the differences between using arteries versus veins and why certain vessels are preferred for long term durability and heart health. 

What We’ll Discuss in This Article 

• The clinical reasons for choosing specific veins or arteries for bypass surgery. 

• The internal mammary artery as the gold standard for heart grafts. 

• How the saphenous vein from the leg is harvested and used. 

• The role of the radial artery from the arm in complex bypasses. 

• The differences in long term success rates between arterial and venous grafts. 

• How surgeons assess the quality of a vessel before harvesting. 

• What to expect at the harvest sites during the recovery process. 

The internal mammary artery: The gold standard 

The internal mammary artery, also known as the internal thoracic artery, is located inside the chest wall. In UK cardiac surgery, it is considered the gold standard for bypass grafting. Because it is an artery, it is naturally adapted to handle high pressure blood flow. Most importantly, surgeons often leave one end of this artery attached to its original source and simply swing the other end down to the heart, which helps maintain its blood supply and longevity. 

Clinical data shows that grafts using the internal mammary artery have exceptional long term durability, often remaining open and functional for 20 years or more. Because of this, it is almost always used to bypass the most important artery in the heart, the left anterior descending artery. Using this vessel significantly improves survival rates and reduces the need for future heart procedures. 

• Most patients receive at least one internal mammary artery graft. 

• It has the highest long term success rate of all graft types. 

• It is highly resistant to developing new atherosclerotic blockages. 

• The chest wall usually has enough collateral circulation to remain healthy after harvesting. 

The saphenous vein: Reliability and ease of use 

The saphenous vein is a long blood vessel located just under the skin on the inner side of the leg. It has been used in bypass surgery for decades because it is easy to harvest and provides a significant length of healthy vessel, allowing surgeons to perform multiple bypasses if needed. During the procedure, a length of the vein is removed and then reversed before being stitched into place to ensure that the small valves inside the vein do not block the blood flow. 

While saphenous vein grafts are highly reliable in the short to medium term, they are more prone to narrowing over many years compared to arterial grafts. This is because veins have thinner walls and are not naturally designed for the high pressure environment of the arterial system. However, they remain a vital tool for surgeons, especially when multiple bypasses are required or if the patient’s arteries are not suitable for harvesting. 

• It can be harvested from either the upper or lower leg. 

• It provides enough length for several grafts in a single surgery. 

• Modern techniques use small incisions to minimize scarring. 

• Long term success is improved by strictly managing cholesterol and blood pressure. 

The radial artery: A secondary arterial option 

The radial artery is one of the two main arteries that supply blood to the hand, located on the thumb side of the wrist. Surgeons may choose to use the radial artery as an additional graft when they want the benefits of an arterial vessel but the internal mammary arteries are already in use. Before harvesting, a clinical test called the Allen test is performed to ensure the other artery in the arm can safely supply the hand on its own. 

Radial artery grafts have shown better long term results than vein grafts, particularly for patients who are younger or have very tight blockages. However, this artery is more prone to spasms than other vessels. To prevent this, patients with radial artery grafts are often prescribed specific medications, such as calcium channel blockers, for the first year after surgery to keep the vessel relaxed and open. 

• Only used if the ulnar artery provides sufficient blood flow to the hand. 

• Offers better durability than a vein graft in many clinical scenarios. 

• Requires specific medication for a period to prevent vessel spasms. 

• Harvesting leaves a scar on the inner forearm similar to a standard surgical incision. 

Differentiation: Arterial versus venous grafts 

The primary difference between arterial and venous grafts lies in their structure and long term durability. Arteries have thicker, more muscular walls that are built to withstand the high pressure of blood being pumped directly from the heart. This makes them less likely to stretch or develop new blockages over time. This is why surgeons prioritise using as many arterial grafts as possible, especially in younger patients. 

Veins have thinner walls and contain valves that prevent blood from flowing backward in the legs. When used as a heart graft, the vein must adapt to much higher pressure. While vein grafts are excellent for restoring immediate blood flow and relieving symptoms like angina, they are generally considered to have a shorter lifespan than arterial grafts. Both types are often used together in a single operation to achieve the best balance of immediate success and long term protection. 

What triggers the choice of a specific graft? 

The choice of which vessel to use is triggered by the results of your coronary angiogram and your overall medical profile. For example, if a patient has severe varicose veins, the saphenous vein may not be suitable. Similarly, if a patient has peripheral vascular disease affecting the arms, the radial artery may be avoided. The surgeon’s goal is always to use the highest quality vessel available to ensure the graft lasts as long as possible. 

Age also plays a role in the decision. In younger patients, surgeons often try to use multiple arterial grafts because they need the grafts to last for several decades. In older patients or those with multiple health conditions, the priority may be a shorter, simpler surgery using the saphenous vein, which still provides excellent relief from symptoms and improves quality of life. 

Conclusion 

Surgeons have several options when choosing veins or arteries for bypass grafts, with the internal mammary artery being the preferred choice for its long term durability. The saphenous vein and radial artery provide essential alternatives when multiple bypasses are needed. Understanding which vessels are used and why helps patients feel more informed about their surgery and the steps taken to ensure the best possible outcome for their heart health. 

If you experience severe, sudden, or worsening symptoms, such as intense chest pain, breathlessness, or fainting, call 999 immediately. 

Authority Snapshot  

This article was written by Dr. Rebecca Fernandez, a UK trained physician with an MBBS and extensive experience in general surgery, cardiology, and emergency medicine. Dr. Fernandez has assisted in cardiac assessments and managed the postoperative care of bypass patients within the NHS. This guide is based on current clinical standards from NICE and the British Heart Foundation to provide accurate and safe information about coronary bypass grafting.