The goal of CABG surgery is not to repair or remove any blocked arteries, but to detour blood around a blockage in a coronary artery . As a result, oxygen-rich blood can flow more freely to nourish the heart muscle. To create the detour, a segment of a blood vessel is taken from another part of the body. The segment is usually taken either from the Internal Mammary Artery from the chest, or the saphenous vein from the leg.

In contrast with traditional vein harvesting, endoscopic saphenous vein harvesting does not require a long incision down the length of the leg in order to remove the saphenous vein. Instead, endoscopic saphenous vein harvesting requires only a few small incisions in the leg to remove the vein, with the aid of a special scope ( endoscope ). The saphenous vein is found on the inside of the leg, from the groin to the ankle.

Patients undergoing this minimally invasive technique not only avoid a long scar along their leg, but they are also significantly less likely to experience wound complications, swelling, leg pain or another surgery – events that can lengthen hospital stay or require re-admission. This is particularly true for patients at otherwise greater risk for leg wound complications, such as those having diabetes or peripheral vascular disease . Patients can therefore have a shorter recovery time and be back on their feet sooner than with traditional vein harvesting.

First, the surgeon will make one to three incisions about an inch long in the leg. Into each incision, he or she will use a thin instrument with a tiny camera at the end to clearly view the process of removing some or all of the saphenous vein. Once the vein has been removed, the incision(s) will be closed. After surgery, other veins will take over for the missing saphenous vein to continue to maintain the health of the leg.

With "beating heart" revascularization, once the bounce of the heart has been minimized, the surgeon can proceed with creating the graft(s). For each blockage, the surgeon will graft one end of the harvested vein to a larger artery (e.g., the aorta ) and will sew the other end into place beyond the blockage in the coronary artery. When finished, blood can flow freely through the bypass graft, around the blockage and into the coronary artery, restoring healthy blood flow to the heart muscle. During traditional bypass surgery, the surgeon stops the heart is in order to perform this procedure, and a heart-lung machine ("pump") takes over the functions of the heart and lungs for about 90 minutes.

Advances in technology now allow the heart to be stabilized with special equipment instead of the heart-lung machine. This off-pump bypass eliminates any risk of complications from the machine (e.g., stroke , memory problems after surgery, or postpump syndrome ). In addition, bleeding is greatly reduced, so patients are less likely to need a blood transfusion. When performed with endoscopic vein harvesting, the bypass is known as off-pump coronary revascularization with endoscopic vein harvesting ( OPCRES ).

Endoscopic saphenous vein harvesting can be safely and effectively done on most patients. However, it may be complicated by preexisting venous conditions (e.g., varicose veins, phlebitis), or even if a patient is too thin. In some cases, the surgeon may find it more appropriate to switch to the traditional technique.