Overview of Endoscopic Vein Harvesting
In the past ten years, a method called endoscopic vein harvesting (EVH), or taking a vein out through a small cut and camera, has become the preferred way to get the greater saphenous vein (GSV). The GSV is a large vein in your leg often used in a heart bypass surgery because it’s easy to remove and it’s long. Because we have a growing number of people needing heart bypass surgery, and many patients need more than one bypass in one operation, there’s a greater need for good, usable veins.
Traditionally, to get the GSV, doctors needed to make a long cut in the skin which often resulted in wound complications and pain. This also meant the patient had to stay in the hospital longer and was likely less happy with the procedure. To solve these problems, the EVH method was developed and improved to make the procedure easier on the patient.
Recently, a study reviewing the cases of almost 28,000 patients found that veins taken out using EVH did not stay open as long as veins taken with the traditional, long-cut method. But, this conclusion only looked at one year of data, and researchers have suggested that results could improve as surgeons get more practice with EVH.
Even though some people have concerns about how long veins taken with EVH will stay open, many studies have found that these veins are just as likely to stay open as the veins removed with the traditional method.
Anatomy and Physiology of Endoscopic Vein Harvesting
The greater saphenous vein is the longest vein in the body, starting from the top of the foot and running all the way up to the groin. Imagine tracing a line from the inside part of your foot, up the inside of your leg and all the way up to your thigh. That’s the pathway of the greater saphenous vein. It is positioned quite close to the surface of the skin, which is different from many other veins that are deep within the muscles.
This vein carries blood back up towards the heart from your foot and leg. It eventually merges with another big vein, known as the common femoral vein, at the groin, thus forming a drainage point for the blood. Because it takes such an external route, it can be more prone to injury. It also means it can sometimes be responsible for discomfort after an operation, or for sensations such as tingling or numbness in your leg.
Why do People Need Endoscopic Vein Harvesting
Endoscopic vein harvesting is a procedure often done during heart bypass surgery. In this process, veins from other parts of the body are taken out to bypass blockages in heart arteries. Although the main use of this procedure is for heart bypass surgery, it can be carried out with other blood vessels too, like the artery under the chest (internal mammary artery) and the ones in the forearm (radial arteries).
That same type of procedure, using the saphenous vein (the large vein running along the inside of the leg), is also used for creating a new passage (fistula) for dialysis in kidney patients. It’s also used in surgeries to improve blood flow to the limbs (peripheral vascular bypass interventions), and to the brain (cerebral bypass surgeries).
When a Person Should Avoid Endoscopic Vein Harvesting
From a practical perspective, there aren’t any strict reasons to avoid endoscopic vein harvesting, a procedure where veins are taken out through a small cut in the skin. However, there may be some concerns when harvesting the saphenous vein, a major vein in your leg. These concerns are common in patients who have complex varicose veins, deep vein thrombosis (a blood clot in a deep vein), and in cases where the vein itself is of low quality and wouldn’t work properly as a channel for blood flow.
Equipment used for Endoscopic Vein Harvesting
To perform a procedure called endoscopic vein harvesting, certain tools must be ready and in good working condition. This method employs a special tool called a zero-degree endoscopic lens. The lens is attached to a high-definition monitor that displays video. This helps the doctor see what’s happening inside your body more clearly.
Connected to this lens is a light source. This provides the needed light inside your body for the doctor to be able to see properly. Apart from this, a carbon dioxide source is needed. This is used to inflate the area where the procedure is done, kind of like a small tunnel. It helps to keep this ‘tunnel’ open during the procedure.
Lastly, a ready-made single-use kit is used to house the endoscope (a small camera enabling interior images) and an electrocautery probe (a tool used to stop bleeding by heating tissue). Different companies make these kits, and while they all work on the same basic principle, there can be minor differences in design.
Who is needed to perform Endoscopic Vein Harvesting?
In the surgery room, the main players are a surgeon and a special type of nurse known as a surgical scrub nurse. Their job is to make sure the surgery goes smoothly. There’s also a surgical technician on-hand. This person is there to handle any issues related to the tools or machinery being used during the operation.
Preparing for Endoscopic Vein Harvesting
For the procedure of vein removal through an endoscope – a thin, tube-like instrument with a light and a camera which allows doctors to see inside the body – there is no specific preparation needed. However, before the procedure, a non-invasive test called a venous doppler mapping is highly recommended. Many healthcare centers believe this test to be essential as it gives very important information about the position and quality of a large vein called the ‘greater saphenous vein’, which is often used in certain medical procedures.
This test, which takes less than ten minutes to perform, lets the doctor know with 95% certainty the size of the vein. The path, size, and quality of the vein are then checked out to decide which side of the vein to use, or even if the procedure should be cancelled. In situations where the vein is smaller than 1.5 to 2 mm, very dilated (widened), or has many varicose veins (twisted, enlarged veins), the procedure might be stopped.
How is Endoscopic Vein Harvesting performed
For this surgery, you will first be put to sleep with general anesthesia. You will lie on your back, and the surgical team will mark the area where they will operate. Information about the blood flow in your veins, captured from an earlier venous doppler mapping (an ultrasound procedure), will be ready for the team to reference. Your leg will be gently bent at the knee (anywhere from 90 to 120 degrees), with a slight outward rotation of the hip joint on the same side. Towels will be placed behind your knee for support.
A small cut, about the length of a standard paperclip, is created on the inside of your lower leg, either above or below the bony bump on the inside of your knee. The exact location depends on the recommendation of the surgeon and the results of prior vein mapping. The surgeon will then identify the Great Saphenous Vein (GSV), a large vein running along the inner side of your leg. They will proceed with careful surgery to expose the vein, and make sure it can be used as planned for later in the procedure. They then introduce a port (a device that allows entry into the body) filled with a special balloon in the incision to seal the tunnel and prevent the escape of carbon dioxide. Then the endoscope, a thin tube with a camera and light, is carefully inserted into the subcutaneous tunnel (a passageway created just beneath the skin) of your leg. Ganular elements in the blood, called heparin, might be used at this step to prevent any blood clots.
To facilitate the surgical process and keep the tunnel open, the area is inflated with carbon dioxide, a harmless gas, between 10 and 13 mmHg (a unit of pressure). The process needs to be carried out gently to prevent any damage to the vein wall or any vessel branches. Once the tunnel is formed above and below the knee as required, the surgeon uses the endoscope electrical tool to cut and seal the branches of the vein and separate the vein from its surrounding tissue. Small incisions are made at the groin and above the inner ankle to remove the vein, which is then extracted through the original incision. The ends of the GSV are sealed with stitches and clips.
The surgical team then checks the tunnel for any signs of bleeding and packs the tunnel with a swab soaked in antibiotics for about five minutes before closure. Some hospitals might place a surgical drain in the tunnel, others use drains only if necessary, or in patients expected to bleed after surgery. All wounds are sewn up neatly using dissolvable stitches and staplers. The leg is then wrapped in a tight, pressurized bandage to prevent bleeding.
Once removed, the vein needs to be examined thoroughly for any signs of tears, blood clots, or separated branches. Other branches should be sealed with small clips, while tears are fixed with nonabsorbable stitches. The vein is then stored in a special solution until ready to be used in the anastomosis, a surgical connection between discrete parts of the circulatory system.
Possible Complications of Endoscopic Vein Harvesting
After a procedure known as endoscopic vein harvesting surgery, the main problem that people might encounter is an infection in the wound created during the operation. However, this kind of infection is much less common in comparison to traditional surgical methods. Problems like blood clotting in a confined space (hematoma), wound splitting (dehiscence), and infections are typically dealt with in a non-invasive manner, but sometimes, additional surgery may be needed to definitively fix the issue.
One possible issue during this procedure might be an injury to the saphenous nerve, which can result in pain and a change in feeling along the inner side of the lower leg after the operation. This could result in odd sensations or increased sensitivity to pain at the skin above the operation site, which is typically a temporary issue. After both open and endoscopic removal of the saphenous vein, it’s not unusual for patients to feel more pain in their leg than in their chest in the initial recovery period. So, the one who’s running the procedure needs to take care not to accidentally harm the nearby saphenous nerve with physical force or heat from specialized surgical equipment, especially in the lower part of the leg where the nerve is close to the large saphenous vein.
The endoscopic vein harvesting procedure pumps carbon dioxide into the body to make it easier to see the vein. This could result in certain problems like air entering the abdominal cavity (pneumoperitoneum), leakage of fluid into surrounding tissues (subcutaneous extravasation), and air bubbles blocking blood vessels (air embolism). The typical response to these complications involves stopping the pumping of carbon dioxide and providing support to the patient’s circulation until the carbon dioxide has been absorbed by the body.
What Else Should I Know About Endoscopic Vein Harvesting?
Endoscopic vein harvesting is now the most commonly used method for obtaining the great saphenous vein – a large vein in your body – for use in several types of surgeries, notably, surgery that bypasses blocked arteries in your heart (known as coronary artery bypass graft surgery).
A recent analysis of 43 scientific studies involving 27,789 patients was performed to compare this method to the traditional open procedure. The results ultimately supported the endoscopic method, stating it was better in multiple ways, including fewer failures of the transplanted vein, fewer heart attacks, lower death rates, and fewer infections at the site of surgery.
