The Second Coronary Bypass Operation I frequently hear comments from patients or their family members such as, "My neighbor told me these bypass operations have to be redone every three to four years. Is that true?" Patients are naturally very apprehensive about surgery to begin with, and when it comes to the possibility of having to repeat a procedure, they want to know the bottom line. Will they need a second bypass operation? If so, how long before it is needed? The answer that heart surgeons and cardiologists would always like to give is, "Never!" The realistic answer, however, is more complicated. One can say, "Hopefully never, but the fact is that every patient is unique, and every situation depends upon a number of variables." When arteries are used as the bypass grafts, they tend to stay open longer than veins . Sometimes, however, the patient's vessels considered for use as bypass grafts may not be in the best shape. This can influence how long the bypass stays open. The arteries normally considered as candidates for grafts may be too small or diseased, or the amount of blood flowing through them may make them unacceptable. Likewise, the diameter of the veins may be too big or too small, or the vein itself may have other abnormalities. The surgeon will not use arteries unless he or she feels they are acceptable, and will try to use the best quality segments of vein available. How long bypass grafts stay open also depends on the condition of the coronary arteries themselves. Ideally, the coronary artery that was originally bypassed was a relatively large artery, appearing to be normal except for one localized area of blockage. Unfortunately, sometimes we find coronary arteries that have multiple blockages, or the entire artery has significant atherosclerosis build-up. In addition, some arteries are only a millimeter or less in diameter (there are twenty-five millimeters in an inch). Sometimes the arteries are so brittle with calcium that it is difficult to find a spot to place a bypass graft, and sometimes the needle used to stitch the bypass to the coronary won't go through the coronary's calcified wall. Also, bypass grafts tend not to stay open as long in insulin-dependent diabetic patients and those with cholesterol disorders.
If you have three, four, or more bypasses, and one or two of them close, it does not necessarily mean you need a second bypass operation. In fact, if they all close, you still may not need a second operation. Even if they all close, you still might not need a second operation, as your cardiologist may have other treatment options. For example, using balloon angioplasty (PTCA) and a stent, the physician may be able to dilate either the coronary artery or the bypass graft. If the first bypass fails, you may be a candidate for translaser myocardial revascularization (TMLR). This procedure can be done either with an operation or with catheters passed from an artery in the groin or arm into the heart. 
The Second Operation In addition to all of these factors, doctors' criteria for recommending a second bypass operation can be somewhat different than they were for the first operation, even though the recovery for each tends to be similar. This is because a second bypass operation is usually complicated by factors not present in the first:
Among patients currently undergoing coronary bypass surgery, there is about a 10-30 percent chance of needing a second bypass. Some of these may be required within the first year. But, for the majority of patients having a second bypass, it will occur more than five (and sometimes more than 20) years later. Third bypasses are uncommon; more than that is rare.
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