Is it safe to follow through the surgery if your gallbladder has inflammation?

My father was diagnosed with gallstones​​ about 4 years ago. It was only one stone that was 1cm long. He's been having gallbladder attacks recently and the surgeon recommended him to get the surgery done but in his recent ultrasound reports, we found out that his gallbladder is swollen because of the stone that is now 2 cm long (acute cholecystitis). He's scared to have surgery with swollen gallbladder.

Has anyone gone through the similar experience? Should we wait for the swelling to get back to normal or just go through with the surgery?