Blue nylon thread started sticking out of my breast 15 years after breast reduction. What should I do?

I had a breast reduction done 15 years ago. Today I noticed something poking out of my skin at the bottom part of the breast. I pulled it with tweezers and pulled about 15 cm of blue nylon thread. I got scared and stopped (so not sure how much more is inside). Could it be a permanent suture? The practise where I had a surgery doesn't exist anymore and I am living in different country now anyway so can't find out more information from my surgeon. Thanks ahead for any reply.