Remove "dead" item from Stream list

Hi All

Can anyone advise?  I'm starting to get used to the new Stream (on Sharepoint) - everything seems OK so far.  One small issue I have which is really bugging me.  I have several items listed in my stream home page where the video has for whatever reason has been deleted/renamed/moved which means when I click on the link I get blank page which message "the site cannot be reached" and a link the old file (which doesnt exist).  

I've tried selecting the item and setting the 'hide'  option which works initially but when I refresh the page the items keep returining to my feed.

I dont know how to clear these dead items from my list of files 

Any suggestions?

Paul