How Serious is an Incision Opening 4 Weeks After Breast Augmentation?

Thank you for your question and for sharing your experience with us.
You will find that every few days the wound will get smaller. Once the
wound closes, it will go through a great deal of remodelling and in many
cases become very acceptable in appearance. If there is a remaining
indentation or widening of the scar that is unacceptable, then I would
recommend waiting six months to year before undergoing any minor
revision. I would avoid working out until several weeks after the incision closes or until you get the go ahead from your surgeon.  It is important that you stay in touch with your surgeon
throughout this process.

An incision opening can be many different things at many different levels. Uusally at 4 weeks it is possibly a suture extrusion. If there is drainage it may be more significant and the implant can become exposed.  The best thing to do it see your surgeon to be evaluated.

Most likely an incisional opening after four weeks at the lower breast fold is superficial and does not  extend deep and expose the implant. I would get evaluated by your plastic surgeon to make sure it is just that. Until you get evaluated, I would stop massaging and banding to avoid any undue stress on the incisional opening. Otherwise there is a big difference between implants that were initially placed above the muscle and changing them years laters due to capsular  problems to a submuscular position. They are not comparable operations in terms of recovery.

A small and superficial opening may be due to a suture working its way out. However, you should notify your surgeon to make sure it is no more serious.

If the incision is only open superficially and there are no signs of infection like redness, drainage, or fever then it may be OK and may heal over time. Your doctor of course should monitor this with you and treat accordingly. If the wound is completely open, exposing the implant, then something needs to be done ASAP. Dependinhg on drainage and other factors it may be possible to irrigate and close the incision, but the success rate is probably 50/50. Each doctor handles this a little differently depending on their findings and their experience. It may be necessary to remove the implant and allow things to heal before replacing it, or even considering other options like fat grafting.

You probably should avoid working out until the problem is resolved one way or another.