The incidence of Obstetrical Anal Sphincter Injuries (OASIS) has been increasing in Canada. Mediolateral episiotomy is protective against OASIS. Episcissors-60 TM is the first pair of scissors designed to cut at a fixed incision angle of 60 degrees, starting 4.5mm laterally from the midline, to reduce human error in estimating episiotomy angle during delivery. The purpose of this study was to determine whether introduction of Episcissors-60 TM into Labour and Birth unit would decrease the incidence of OASIS.

A before and after quality improvement study was conducted between April 1, 2020 and March 31, 2021. This study was approved by the Research Ethics Board. All patients who had a vaginal delivery were included in this study. All healthcare providers who perform vaginal deliveries on Labour and Birth unit were offered an educational session. Episcissors-60 TM were then introduced into Labour and Birth unit. The primary outcome measure was the change in incidence of OASIS before and after introduction of Episcissors-60 TM. Secondary outcome measures were episiotomy rates before and after introduction of Episcissors-60 TM, device-related adverse events, and provider satisfaction and feedback. Data was analyzed using Chi-square tests, independent t-tests, and Mann-Whitney tests.

A total of 1,383 vaginal deliveries occurred prior and 1,254 vaginal deliveries after introduction of Episcissors-60 TM. There was a statistically significant decrease in the total OASIS rate from 7.37% of all vaginal deliveries prior to 5.37% after introduction of Episcissors-60TM (p=.037). The episiotomy rate was 11.42% prior to and 9.97% after introduction of Episcissors-60 TM (p=.228). Episcissors-60 TM were almost exclusively used by obstetricians and had poor uptake in family physician and midwife provider groups. OASIS rate in women who had an episiotomy was 12.02% before and 13.60% after introduction of Episcissors-60 TM (p=.421). Three providers reported an adverse event.

Although introduction of Episcissors-60 TM resulted in a statistically significant decrease in total OASIS rate, there was no statistically significant difference in OASIS rates within the subgroup that received an episiotomy. Therefore, reduction in the total OASIS rate in this study cannot be attributed to the use of Episcissors-60 TM.

To decrease OASIS rates and morbidity associated with OASIS, a combination of preventative interventions is required. It is important to define individual OASIS risk factors for each patient to determine whether an episiotomy could reduce that individual’s risk of OASIS. Future research needs to focus on modifiable risk factors and protective measures at the time of vaginal delivery that may have a greater impact on the overall OASIS rates, in comparison to modification of episiotomy technique alone.