Failed Muscle Repair After Tummy Tuck, What Would Be The Most Likely Reason For This? (photo)

Failure of fascia repair after abdominoplasty is almost unheard of. You should check with your surgeon as a revision might be indicated.

A variety of factors may be involved.  Personally, I use permanent sutures, although others use long lasting dissolving sutures.  The vomiting is another risk factor.  Abdominal exercises, especially when resumed too quickly, or weight gain are two more factors.  And, finally, patients have different quality fascia ( the abdominal wall canvas-like layer that envelops the muscles).  Poor quality fascia, which is essentially genetic, will not hold a repair well.  It is worth considering a repair with permanent sutures.  Good luck.

Based on what I read here, the likeliest cause is the vomiting. We all try to minimize nausea and vomiting, but not with 100% success. This can happen with permanent or dissolving sutures. 

There are still discussions about the relative benefits of permanent vs. non-permanent sutures. Non-permanent sutures have been demonstrated to be equally effective in abdominal wall closures since the 1970'ies. By the time the dissolving sutures are gone, the healing strength of the wound is stronger than the sutures were. 

All the best.