Who/what says that you have to periodically review your documents?
If your procedures say you have to review the documents every X months/years, also state if/how you will create a record of the review. Make it easy on yourself.
Maybe keep a simple review log in Excel.
Maybe send yourself an email saying "on this date I reviewed document ABC123 Rev C and found it acceptable as-is". There! You have a record.
When reviewing a document for periodic review, I was taught that the document should be reved even if no changes have occurred, just so there is an audit trail of the periodic review. Does anyone have a reg that points to this?