In the situation where the physician set out to perform an upgrade to dual-chamber ICD, but was unsuccessful due to subtotal occluded left subclavian vein, what would be the proper coding? The existing system was placed back into the pocket. I have not ran across this situation in the five years I have been coding for this EP doc. Would I use both codes for removing and replacing with a 52 modifier since there was an attempt made? I just would like some outside input. Thanks.