fortune favors the bold. so yes, approach an attending and ask if you can go see the OR. tricky part is getting a resident to engage you during a case. perhaps rounding with the team in the AM and staying for a whole day of work would be more educational. anyways.
but as has been said all over the place on this website, focus on med school, do well with your boards, get involved in some research, and keep an open mind on all things (fields) you approach. in the end, you might just find a 3 yr residency more appetizing than a 7 year battle (most people do).
methinks, very few people actually finish in the field that they start off thinking that they are interested in.
goodluck