...there are also a number of computerized replica-type machines and programs that let you do virtual surgery.
As a medical student, I've had the opportunity to perform a variety of procedures on a pig. However, I was not REQUIRED to, and I simply scrubbed in and observed the whole thing. No one but one fellow student asked why I was not participating. It was not held against me in any way. I felt, actually, that I missed nothing with my decision, and those who participated enjoyed being able to perform procedures that they will never do again (as they were on their required surgery rotation but did not intend to pursue a surgical residency). In this case, you will more than likely be able to find wiggle room.