A couple related experiences, but not me (my only relevant experiences are a half dozen trips for stitches and once to pick gravel out of my back after an unfortunate incident with a rabbit).

My brother went under to get his knee scoped. He woke up with a 12" scar. The doc got in, and found so much more than the xray/mri showed he had to open him up. He's still running, biking, and skiing, albeit carefully. Finished a marathon, too.

My daughter was born with a "branchial cleft" - a birth defect resulting in a tube of skin going into her neck, which frequently oozed juice. They also often lead to cysts that cause really serious trouble. When she was 4 we (finally) decided to remove it. We visited experts at Childrens' in DC (a fabulous teaching hospital), did scans and even physical probes into the hole. Scheduled surgery.

On the day, she went in and under (5, 4, 3... zzz). We waited. And waited. And waited. And worried. And worried. Eventually - a couple hours after it was supposed to be done - the doc came out, gray, and his first words were "It was awful!" He went on to say the cleft was way deeper in her neck than expected, a "Y", branching on either side her carotid artery, with one end terminating in her esophagus.

Fortunately everything worked out - just a small scar on her neck. (And she got to freak out her preschool teacher when she brought in her anesthesiology mask for show and tell!)

-jk