Suture failure is not your problem; only two months following your muscle repair, the fascia fuses and is fail proof. Some plastic surgeons use Vicyl for this repair, which only lasts one to two months.  One possible explanation is a hernia may have developed (an actual tear in the muscle). This is an important distinction and will require you not to have a revision of your suture line, but you need to consider the TRI Modality muscle repair which requires direct repair + bilateral component separation + Xenograft onlay repair.