Andy Leondard describes steps you can take to maintain the SSIS Catalog:
Back It Up
As with all SQL Server database, please back up SSISDB. What follows is a (very) basic guide describing one simple method to backup your SSISDB database. Please, please, please learn more about SQL Server backup and restore options and their implications before backing up an SSISDB database in your enterprise. Feel free to use the steps I describe on your laptop or a virtual machine. And please remember…
Backups are useless. Restores are priceless. Conduct practice Disaster Recovery exercises in which you restore databases and then test functionality. You’ll be glad you did. Here is a link containing Microsoft’s advice on restoring the SSISDB database in SQL Server 2016.
The advice is pretty similar to what you’d expect for any other database, but there are a couple twists around SSISDB functionality, so do read on.