Do people need veins for heart bypass?

Sometimes. The best vessels for bypass surgery are the internal mammary arteries (there are two). In patients that require more than two bypass, leg veins (saphenous) are often used but generally don't last as long as mammary arteries.
Many available. They don't use diseased sahenous veins. Don't worry if you have to have vein treatment, there are many veins available for heart surgery.

Related Questions

What is the role of your saphenous vein for heart bypass surgery?

The bypass tube. The greater saphenous vein and occasionally the lesser saphenous vein ( superficial veins in the leg ) are the usual "tubes" used for coronary artery bypass and frequently for other artery bypass operations. Read more...
Bypass conduit. Internal thoracic arteries and saphenous veins are used to bypass the obstructed native coronaries. Depending on location and number if diseased vessels , more length of vein may be harvested, prepared , reversed due to intrinsic valves, and sewn to aorta as inflow, and to distal coronary to provide new flow to heart. Read more...

I had the vein removed from my thigh 8 yrs ago when I had a heart bypass. Am getting a lot of pain at one end of scar. Any reason for this?

Yes. Any symptom has reason. As to what the actual reason, is a challenge to be evaluated. Your symptom maybe related to saphenous nerve-related cause. If after medical rx, pain is still persistent and disabling, neuroma may need to be removed under local anesthesia. Read more...
Possible neuroma. Small nerves travel i close proximity to the vein and when injured (which is not always preventable) they may cause the surrounding are to be numb or may produce a neuroma which is a benign pressure sensitive tumor that may cause pain or electrical shocks. If these do not respond to desensitization they may need to be destroyed or excised or transferred to muscle/bone. Read more...

Is there a significant difference between getting arteries from your arm for heart bypass instead of veins from your leg?

Maybe better. There is debate in cardiovascular surgery whether radial arteries have better long term results than saphenous vein grafts. Assuming the surgeon is experienced in handling the radial artery, the results are at least as good as vein grafts and maybe better over the long run. Read more...
Yes. The patency rate (staying open longer) is greater long term for arteries. The reason they are not used 100% of time is limited availability. Read more...

For coronary heart bypass surgury, which vein they cut from lower limb to put there?

GSV. Usually the great or small saphenous vein in the thigh or calf, respectively. Many places are using arteries from the chest muscle also. Read more...

In coronary bypass surgery which blood vessels supply the wall of the heart with blood?

See below. The Left anterior descending with its branches, diagonals and septal perforators, the left circumflex with its branches, obtuse marginals, and the right coronary artery with its branches, especially the posterior descending and posterolateral branches. Read more...

What are the risks and benefits of stenting diseased blood vessels / heart bypass surgery / heart transplant / artificial heart valve transplant?

Way too complex. This question is way to complex for a short text Q&A. Individual patient information is needed to really discuss risks and benefits. This discussion needs to be with a live cardiologist and/or cardiac surgeon. Read more...