Uterine scar defects

This issue contains several articles relevant to uterine scar weakness or defects, and finding the optimal materials and techniques for wound strength. In August 2008 we published an editorial (MacLean & MacLean, 2008) suggesting that the transition from a two layer uterine wall closure at Caesarean section with chromic catgut to the use of polyglycolic acid or polyglactin materials may be associated with the increasing numbers of reports of uterine scar rupture and Caesarean scar pregnancies. We suggested that surgeons and in particular orthopaedic surgeons were more aware of wound strengths, and that there should be more research in Obstetrics and Gynaecology into suture materials and subsequent performance of the wounds.

The article by Uppal et al (2011) from New South Wales, Australia, describes the findings at ultrasound scanning of fluid filled uterine wall defects in 29 (40%) of 71 women who had previously undergone Caesarean section. They describe that the presence of these uterine scar defects was significantly associated with prolonged menstruation or post-menstrual spotting. We are not told and they probably did not know how these Caesarean uterine wounds were repaired, but this observation, relatively recently reported, may follow a change in repair technique or suture material for the Caesarean section.

The article by Okafor et al (2011) describes successful management of five pregnancies after the uterus had ruptured in an earlier pregnancy and had been repaired using chromic catgut No. 2 gauge in two layers. It is interesting to surmise what the outcomes might have been if other suture material had been used. Odejinmi et al (2011) describe a case where a uterine wall defect was repaired with polyglactin while removing a broad ligament tumour, with rupture of the uterus in the site of repair at 31 weeks in the subsequent pregnancy.

Madhuvrata et al (2011) describe a small study where Vicryl mesh or sutures of polyglactin versus polydioxanone were used in repairing pelvic organ prolapse. While chromic catgut was not studied, the findings suggest that the faster absorbing polyglactin may have an advantage over the other and slower disappearing suture. The study demonstrates that well conducted studies with defined endpoints can provide important information on subsequent wound strength.

In our Editorial we questioned whether it was right to abandon chromic catgut for uterine repair. It is not possible to obtain sufficient supplies of suture to do that study now, but I welcome readers' thoughts on whether we are increasing the risk of iatrogenic consequences, and whether there are opportunities to conduct studies of uterine strength following the increasing numbers of Caesarean sections being performed.