Obstetric Anal Sphincter Injury After Episiometer-Guided Versus Conventional Episiotomy in Instrumental Deliveries: A Randomized Controlled Trial

Introduction and Hypothesis

Guidelines recommend episiotomy for instrumental vaginal delivery with an optimal incision angle of 60° to protect the anal sphincter. The “Episiometer” is a new device promising a 60° incision angle. We compared the incidence of obstetric anal sphincter injury (OASI) and post-repair suture angle of episiotomies made with conventional “eyeballing” versus Episiometer guided during instrumental delivery.

Methods

We conducted this randomized controlled trial in a tertiary care teaching institute in southern India after ethical committee approval, trial registration, and informed consent. We randomized (block) 328 pregnant women aged 18 years and above with term, singleton fetuses delivered by instruments into Episiometer-guided (164) or conventional episiotomy (164) groups (allocation concealed). We compared the OASI (identified clinically) and the suture angle measured from the midline (assessor blinded) in the two groups. We followed up on the subjects at 6 and 12 weeks to assess perineal pain and fecal/flatus incontinence.

Results

The incidence of OASI of 0.61% in the Episiometer group was significantly lower compared with 4.88% in the eyeballing group (Chi-squared = 5.6; p = 0.02; adjusted risk ratio = 5.9; CI 0.7–46.1; p = 0.09). A significantly higher proportion of subjects (59.1%) in the Episometer group had a post-suture angle between 36 and 40° compared with 36.6% in the eyeballing group (Chi-squared = 21.8, p < 0.001). We found no significant difference in the perineal pain or Wexner score during follow-up.

Conclusion

The Episiometer-guided episiotomy during instrumental delivery resulted in a significantly higher suture angle and lower obstetric anal sphincter injuries than with conventional eyeballing.