I'll tell you after Thursday after my laparoscopy I have a 8 cm dermoid, doc thinks he can save my ovary...I pray that he does....my advice look around for a robotic laparoscopic surgeon.
Ask your doctor. Be sure to get a really good doctor, don't just let anyone do the surgery, if there is a chance someone really experienced at this kind of surgery could save the ovary.
I assume your primary concern is loss of future childbearing. If so and you think you might lose the ovary in the surgery, you could have a procedure to try to hyperstimulate it and draw out some eggs beforehand. You could do egg freezing, though it is not done widely and is not always successful. If you are married, you could do embryo freezing (which has a higher success rate than egg freezing, and is done much, much more widely). If you don't think you'll ever get married but want to have a child some day, you could do embryo freezing with an anonymous donor's sperm.
If you have already had all the kids you want and are simply concerned about the loss of your last ovary, again, get a second and third opinion and find a really good doctor, to see if they can avoid the loss. Also, as a back-up, talk to a good doctor about hormone replacement in the event it is lost. It can make a world of difference.