Transverse uterine incision non-closure versus closure: an experimental study in sheep

This study was designed to investigate whether the non-closure of the layers of the uterus during low transverse cesarean section would result in healing and have advantage on closure.

Thirty pregnant ewes randomly divided into two groups. Each group included 15 ewes. Each ewe was anesthetized at para-vertebral region with the injection of 20 ml Prilocine 2%. Following left transverse abdominal incision, a transverse incision was made on the uterus and lambs were delivered. In the first group, uterine incision line was left open. In the second group, uterine incision line was sutured with no. 1 Chromic catgut by Schimiden technique. In both groups, all layers of abdominal wall except skin were sutured as en-bloc with Vicryl no. 2, by continuous suture technique. Skin was sutured with no. 00 silk interrupted sutures. The ewes were slaughtered four months after cesarean section. A coworker was asked to open the abdominal cavities, and score the intra-abdominal adhesions. Tissues taken from incision line of each uterus were fixed in 10% neutral buffered-formalin and were embedded in paraffin-block. Sections were cut and stained with hematoxylin-eosin. A pathologist, who knew nothing about the study, evaluated all sections, and reported the findings. Student's t test was used for comparison of mean ewe age, gestational age, and mean operation time of the two groups. Z test was used for comparing the ratio of the two groups by means of histopathological findings.

No cervical dilatation and delivery of the placenta were seen during the four week follow up period. The average operating time was significantly less for the non-closure group (48.07 +/- 3.83 minutes) than for the closure group (62.53 +/- 6.57 minutes; p = 0.001). The ranges of myometrial necrosis (100% versus 13.3%; p = 0.001) and endometriosis (53.3% versus 00.0%; p = 0.001) were significantly higher for closure group than for non-closure group.

It was found that non-closure layers of the uterus along low transverse cesarean incision proves to have no adverse effect on immediate and late postoperative period in ewes. Our data showed that non-closure of all layers of the uterus results in significantly less muscular necrosis and endometriosis than closure group. We suggest that lower uterine incision can be left unclosed or, at least, simple closure can be preferable instead of vigorous locking technique.