INTRODUCTION: 

• There are randomized studies evaluating the addition of the second layer, but generally following locked suture technique  
• Bennich et al. (Ultrasound Obstet Gynecol, 2016) investigated the impact of adding a second layer to a single unlocked closure of a cesarean uterine incision on residual myometrial thickness (RMT) as a proxy for uterine rupture risk 

METHODS: 

• Randomized double-blind controlled trial (2008-2013) 
• Nulliparous women > 37 weeks scheduled for cesarean section  
• Women randomized to 
  •  Single-layer technique (continuous) 
  •  Double-layer technique 2nd layer (continuous – up to 3 separate sutures for hemostasis if needed)  
• At discharge 
  • Transabdominal ultrasound  
• At 5 months  
  • Saline contrast sonohysterography at a minimum of 5 months postpartum 
• Ultrasound examiners were blinded to closure technique 

RESULTS: 

• Single layer n= 35; double-layer n= 38 
• No difference in age, BMI or perioperative characteristics (e.g., duration of surgery) between groups  
• When comparing groups, there were no difference in the RMT whether at discharge (mean ± SD, 20.2 ± 8.0 mm vs 21.0 ± 9.7 mm) or after 5 months postpartum (5.7 ± 2.9 mm vs 5.7 ± 2.2 mm) 
  • RMT was approximately half that of the normal myometrium at both examinations 
• There were also no differences in gestational age at delivery, duration of surgery and perioperative blood loss 

CONCLUSION: 

• Double-layer closure of C-section incision does not increase RMT compared with single-layer closure when an unlocked technique is used 
• Some previous studies demonstrated a larger RMT with double-layer used locked first-layer 
• Authors suggest that unlocked technique for the first-layer is at least as good as double layer, and a first-layer locking technique may result in reduced RMT and possible increase risk for rupture 

Learn More – Primary Sources

Impact of adding a second layer to a single unlocked closure of a Cesarean uterine incision: randomized controlled trial 

Related ObG Topics:

Suture or Staple for Cesarean Section Skin Closure?

Which is the Better Suture to Prevent C-Section Wound Complications? 

C-Section Skin Closure: Glue or Subcuticular Sutures?

Do Different Surgical C-Section Techniques Affect Outcomes?