Follow-Up: What is happening with my stitch abscess post breast reduction?

By the looks of it, the sinus has ongoing drainage.  It looks red and slightly inflamed.

I definitely think this is worth having your surgeon have a look at and this is a reasonable expectation.  I am sure he would like to fix the problem for you and this should not be a very complicated or extensive surgery.

My suggestion is for you to organize a consultation and see him at the earliest possibility. 
Good luck

Usually these stitches resolve on their own. There are obviously pros and cons of surgically removing the stitch and you need to discuss this with your PS. 

Sorry you are experiencing this relatively common post op problem.  Return to your doctor and provide your details and concerns.  It is possible a. Suture could still be present and the area needs probing to remove the problem suture.   Rarely is extensive operative intervention beneficial in this type of situation.  Good Luck!