What happens if you leave surgical staples in?

Some surgical staples are resorbable , I am assuming you are asking about those which aren't. Since surgical staples are not "natural" they would likely induce a foreign body giant cell reaction- or a scar tissue would form around them. I encourage you to take up the matter with the surgeon if you are concerned,

Surgical staples and sutures left in too long can result in significant cosmetic changes depending on their location. This is most pronounced following repair of facial lacerations where even using very thin sutures we try to take them out within 4 to 5 days since the sutures themselves will leave frankenstein-style cross-hatched scaring. Elsewhere skin sutures are left in for 7 to 14 days max.