As a GP, I have reviewed the evidence. It seems that the natural cut-off for ill effects vs lung and heart diseases is at about 1 cigar a day. Above that and you are accumulating risk. At or below that then you won't be increasing your risk in any great statistical fashion. The exception to that is larynx (a part of the throat) cancer (even many of the other head and neck cancers obey the 1/day rule). For some reason, any cigar smoking does increase your risk.
The assumptions are: you don't inhale. Other precautions I would include would be don't swallow your saliva while smoking (the researchers theorize that swallowing contaminated saliva may lead to this unavoidable risk, I find this precaution easy to follow, because frequent mouth rinsing does seem to improve the flavour of even the best tastiest cigars). Another modifier to the risk profile is whether you have ever been a smoker before; this may be because of previous accumulated risks "re-awakening" or may have to do with the whole inhaling thing again.
So, make no mistake, we are increasing our risks by using tobacco products. However, the amount of risk and the risk-to-benefit ratio that comes with choosing to do things you enjoy are probably leaning in your favour to have an enjoyable life. Someone on this board will die because of their cigar habit, but its not likely to be you (statistically
)
That all said, if I had surgery, I would hold off on the cigars for the time being. Something about tobacco does tend to slow the healing process. The last thing I want is poor healing after a surgery. Thus, in that circumstance I would lean to the side of caution. Once the surgery is completely behind me, then I would breathe a sigh of relief and then promptly inhale a stogie of relief.
Cheers
Cyanide