Double or Single Layer Closure for Best Cesarean-Section Outcomes?

BACKGROUND AND PURPOSE:

  • Niche on ultrasound describes a triangular anechoic area at the site of a previous cesarean section
    • Seen with saline or gel contrast hysterosonography
    • Residual myometrium thickness (RMT) at apex of niche is thin
  • Possible that RMT thickness related to closure technique
  • Stegwee et al. (BJOG, 2017) examined whether uterine closure technique after cesarean section has an impact on maternal and ultrasound outcomes

METHODS:

  • Systematic review and meta-analysis
  • Literature search of randomized controlled trials (RCTs) or prospective cohort studies that evaluated uterine closure techniques and reported on ultrasound findings, perioperative or long-term outcomes
  • The following techniques were included in the analyses
    • Single- versus double-layer closure
    • Locked versus unlocked suturing
    • Inclusion versus exclusion of the decidua
  • Outcomes
    • Ultrasound findings post cesarean section
    • Intra-operative and short-term post-operative findings
    • Gynecologic symptoms
    • Reproductive outcomes

RESULTS:

  • Meta analyses performed using twenty studies
  • Data was analyzed from 15,053 women
  • RMT decreased by 1.26 mm after single- vs double-layer closure (95% CI -1.93 to -0.58; P=0.0003)
    • More pronounced with locked sutures
  • Healing ratio (RMT/adjacent myometrium thickness) was decreased with single-layer closure (Weighted mean difference -7.74%, 95% CI -13.31 to -2.17)
    • More pronounced with locked sutures
  • Niche more common when the decidua was excluded (RR 1.71, 95% CI 1.11-2.62)
  • Dysmenorrhea occurred more often in the single-layer group (RR 1.23, 95% CI 1.01-1.48)
  • Incidence of uterine rupture was similar (RR 1.91, 95% CI 0.63-5.74) between groups

CONCLUSION:

  • Double-layer unlocked sutures were preferable to single-layer locked sutures regarding RMT, healing ratio and dysmenorrhea
  • Niche prevalence increased with excluded decidua

Learn More – Primary Sources:

Uterine caesarean closure techniques affect ultrasound findings and maternal outcomes: a systematic review and meta-analysis.

Does Adding a 2nd Layer to Uterine Closure of a Cesarean Section Alter Outcomes?

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 

Single or Double-Layer Closure at C-Section and Resulting Uterine Thickness

PURPOSE:

This study by Vachon-Marceau et al. (AJOG, 2017) aimed to determine if there is a difference in lower uterine segment thickness depending on single or double-layer C-section uterine closure.

METHODS:

Prospective Cohort Study

RESULTS:

There is an increased risk of uterine rupture during a trial of labor following C-section. Uterine thickness on ultrasound has been studied as a proxy for scar quality and risk of rupture in future pregnancies. In this study, 1,613 women underwent transabdominal and transvaginal ultrasounds in their third trimester to assess lower uterine segment thickness and scar defects resulting from previous C-section. The sonographers were blinded to clinical information.  495 (31%) women had previously underwent a single-layer and 1,118 (69%) had a double-layer closure. Women who had a double-layer closure had thicker lower uterine segments than women with single-layer closure with a difference of 0.11 mm (95% CI, 0.02-0.21 mm). Using multivariate logistic regression to account for variables, double-layer closure was less likely to result in a thin lower uterine segment thickness of < 2.0 mm (odds ratio 0.68; 95% CI, 0.51-0.90). Double-layer closure was also associated with a decreased risk of uterine scar defect with a relative risk of 0.32 (95% CI, 0.17 – 0.61) at birth. Type of thread (catgut vs. synthetic) used for closure had no impact on lower uterine thickness.  The authors conclude that double-layer closure resulted in reduced risk of uterine segment thickness <0.2 mm and visible uterine scar defect on ultrasound in the third trimester.

Learn More – Primary Sources:

Single versus double-layer uterine closure at cesarean: impact on lower uterine segment thickness at next pregnancy