Should I Be Concerned About A Cataract Surgery With A Rare Tear That Required Stitches?

Hi. My mum has had a cataract op today and has said to me on the phone that there was a tear which has required stitches. This is very rare, she was told. Should I be concerned? She is nearly 90 and has to go back next week to have the stitches out and was in the hopsital today for about 6 hours, much longer than predicted.