An evaluation of uterine scar integrity after cesarean section in rabbits.

Cesarean sections were performed on 30 rabbits at term pregnancy. Two incisions were made in each of the two uterine horns, and each incision was closed according to a predetermined method (continuous, everted; continuous, inverted; interrupted, everted; or interrupted, inverted). Tissue from the uterine scar region was sampled at three different time periods (5-8 days, 12-15 days, or 28-30 days) post-surgery to evaluate the degree of uterine healing by a variety of histologic criteria. The initial healing response in the scarred region occurred around 28-30 days post-surgery. The different uterine closure techniques did not appreciably influence the healing response in this study. We evaluated tensile strength in 36 uterine muscle specimens containing the scar obtained from nine animals in the 28-32-days post-surgery group. Of these 36 specimens, 86.1% tore through the muscle instead of through the scar when tension was applied to the muscle.