Is locking during continuous suturing better than no locking for uterine closure in a cesarean delivery?

Non-Locking Continuous Suture is Preferred for Uterine Closure During Cesarean Delivery

For uterine closure during cesarean delivery, use a continuous non-locking suture technique, as locking sutures cause excessive tissue tension leading to tissue edema, necrosis, and impaired healing. 1

Evidence-Based Rationale

Why Non-Locking Technique is Superior

• Non-locking sutures distribute tension more evenly across the entire length of the suture line, reducing focal points of tissue ischemia 1
• Locking sutures cause increased tissue damage and result in weaker scars compared to non-locking techniques, as demonstrated in other tissue types including fascia and skin 2
• Residual myometrial thickness (RMT) is significantly reduced with locked sutures—single-layer locked closure results in RMT of 3.8 mm versus 6.1 mm with unlocked double-layer closure (P < .001) 3
• Healing ratio is significantly worse with locked sutures—54% with locked single-layer versus 73% with unlocked double-layer (P = .004) 3

Clinical Outcomes Supporting Non-Locking Technique

• Dysmenorrhea occurs more frequently with locked single-layer closure compared to unlocked techniques (RR 1.23,95% CI 1.01-1.48) 4
• Scar defects (niches) are more prevalent when locked sutures are used, which may lead to long-term gynecological complications 4
• No increase in additional hemostatic sutures is required with non-locking technique despite theoretical concerns about hemostasis 2
• Operating time is minimally affected—the non-locking technique adds negligible time while providing superior tissue healing 2

Recommended Technique

Layer Configuration

• Two-layer closure is preferred over single-layer, as it may be associated with lower rates of uterine rupture in subsequent pregnancies, though evidence quality is low 1, 5, 6
• The first layer should be continuous and non-locking, excluding the decidua to reduce niche formation 4, 3
• The second layer should be imbricating to provide additional strength without excessive tension 2

Suture Material Selection

• Use delayed absorbable monofilament sutures such as polyglactin 910 (Vicryl), poliglecaprone-25 (Monocryl), or chromic catgut 5, 6
• No specific suture material has demonstrated superiority over others for uterine closure 5, 6
• Consider triclosan-coated Vicryl (Vicryl Plus) when available, as it reduces surgical site infections (OR 0.62,95% CI 0.44-0.88) 5

Critical Technical Points

What to Avoid

• Never use locked sutures for the first layer, as this creates focal points of excessive tension that strangulate tissue 1, 3
• Do not include the decidua in the closure, as excluding it reduces niche prevalence (RR 1.71,95% CI 1.11-2.62 when decidua is excluded) 4
• Avoid overly tight sutures that can impair tissue perfusion and healing 5

Additional Surgical Considerations

• Use blunt expansion of the transverse uterine hysterotomy rather than sharp extension to reduce blood loss 1, 6
• Do not close the peritoneum, as this does not improve outcomes and increases operative time 1, 5, 6
• Reapproximate subcutaneous tissue if depth is ≥2 cm to reduce wound complications 1, 5, 6
• Use subcuticular suture for skin closure rather than staples to reduce wound separation 1, 5

Common Pitfalls

• Defaulting to locked sutures out of habit or concern for hemostasis—evidence shows no increased bleeding with non-locking technique and superior long-term outcomes 2, 3
• Using single-layer locked closure to save time—while this reduces operating time by approximately 5 minutes, it significantly compromises scar healing and increases long-term complications 7, 4, 3
• Including the decidua in the closure—this increases niche formation and may contribute to future complications 4