Should I microchip again?

So long story short, about 5 months after my boy Munchie was microchipped my husband was petting him at night and felt a bump on his neck, I turned on the light and it was his microchip, he essentially developed an abscess around it and 'spit it out'.  In talking to the company and research online, I figured out it was his body's way of rejecting the foreign object.  The company provided a new microchip, but due to him doing that I have not had it done, that was when I was a kitten so about 6 years ago.  Should mommy go ahead and have it implanted?  Should she try another brand?  Or should she just not have it done?  Here are pictures from when it happened, and yes that is his microchip.  http://cprcheetah.tripod.com/blog/index.blog/1749147/muncies-microchip-abscess/

I would ask a vet you trust whether the same thing is likely to happen again or  not and take that advice.  If you have a regular vet who you visit on a yearly basis, they should probably be willing to discuss this on the phone with you free of charge.  I don't have any personal experience with this and I have no idea if, having rejected it once, he is more likely to reject it again.  I probably would try again if you determine it's safe, though, since I do think cats are safer with microchips than without them.

Well my dad is a semi-retired Vet and his suggestion was to give it a try again and if it happens again then we know that his body will just reject it.  I work for a different vet and haven't yet asked them their opinion, but Microchipping is one of the 'free' perks of working there so it go me to thinking that maybe it was time to chip him.  I need to get my 2 youngest girls chipped as well, everybody else is chipped.  I know chipping is safest for them, I know of a dog who was lost for 4 years and reunited with her owners due to a microchip.  My kitties are stritcly indoors, but there is always the chance of something happening and one of them getting out.