Are you talking about surgical clips inside the abdomen or surgical staples on the skin? There are different techniques for appendectomies and doctors vary on the type of closure they perform. As AnnieBrooke noted, surgical staples are one way of closing wounds. They are on the outside of the scar and removed after a few days by your doctor.
Inside the abdomen, your doctor may have used surgical clips instead of sutures where he removed your appendix. Such clips are made from biodegradable materials and are considered safe when left inside. Future scans may note that you have surgical clips in your appendix area. This is normal and not of concern.
I have multiple surgical clips that show up on scans that were left after my tumor removal and cancer staging surgery. The presence of surgical clips does not present a problem for having future scans like a MRI. Hope this helps!
Shelly
If you mean, is metal left inside your stomach, no, they don't. They remove the little piece of dead tissue and suture up the gap and that is that. They use stitches, which dissolve. It is possible that they will use metal staples to close your skin. Those, they remove after your incision has healed enough to stay closed without help. They leave less of a scar than the old nylon stitches they used to use to close the skin.