I’ve not had the same surgery as you but did have surgery that affected my levels last year.
The surgery caused stress (not surprisingly) which pushed my BG up. This was probably exaggerated by sitting around resting rather than my manic gym sessions.
I increased my basal by 40% after a bit of trial and error and found this helped to bring my BG down.
I tested a lot to ensure this extra insulin was still needed and reduced it after about 2 weeks.
Good luck with your recovery.