@caroljeand The half-life of Kevzara is approximately 10 days and it takes 5 half-lives before a drug is considered completely out of your system. That would be 50 days. You will only be without some Kevzara in your system for a very short time. True, the last 10-20 days the amount would be very low.
Not sure how delaying surgery would help since the timeframe would be the same, unless you believe you will be coming off Kevzara completely in the near future.