Reproductive Surgery Uterine Surgery

"Uterine closure after cesarean delivery: surgical technique, biological rationale, and clinical implications."

Bujold E, Romero R

Published January 2026 American Journal of Obstetrics and Gynecology, 233(6), S82-S102
DOI 10.1016/j.ajog.2025.10.007 PMID 41485855 PMC PMC13306931

RRM Academy Synopsis

Excluding the endometrium when closing a cesarean lowers scar defects

Cesarean scars heal better when the stitches skip the uterine lining, two obstetrics researchers conclude in a review. Leaving the lining out of the stitches halved the risk of scar defects in four pooled randomized trials of 392 women.

Key Findings

  • Pooling four randomized trials of 392 women, closures that excluded the endometrium cut the risk of scar defect by about half (RR, 0.53; 95% CI, 0.34 to 0.82).
  • In the 2Close trial, scar niches appeared in 59% (150/253) of single-layer closures that excluded the endometrium and 72% (471/656) of those that included it (RR, 0.83; 95% CI, 0.74 to 0.93).
  • In an observational study of 202 women, hysterosonography showed scar defects in 73% (93/127) when the closure included the endometrium and 8% (6/75) when it excluded it.
  • In a quasi-randomized trial of 137 women, scar defects appeared in 6% (2/36) with a 2-layer closure that excluded the endometrium and 34% (17/50) with a single-layer closure that included it.
  • The authors report that randomized trials have not shown a lasting benefit from the third, serosal layer of their closure.

Interpretation

This narrative review pools randomized, quasi-randomized, and observational data on cesarean stitching. Excluding the uterine lining from the stitches was linked with fewer scar defects across every study type. The authors propose a three-layer closure that skips the lining and reinforces the deeper muscle wall. The 2Close trial compared this directly, but only within single-layer closures. Two other studies tested closures like the proposed three-layer method. The findings support larger trials of this approach.

RRM Context

The review names displaced lining tissue as a possible cause of adenomyosis and endometriosis in the scar. Restorative reproductive medicine looks for the root cause of pelvic pain, abnormal bleeding, or infertility after a cesarean. Scar healing is one place to look.

Abstract

Normal uterine function depends on cyclical regeneration and the capacity to sustain pregnancy. A cesarean incision represents an injury to this remarkable organ. Although the uterus possesses exceptional healing potential, cesarean delivery increases the risk of secondary infertility, pelvic pain, uterine rupture, and abnormal placentation in subsequent pregnancies. The two most important determinants of successful hysterotomy healing after cesarean delivery are the location of the incision and the surgical technique used for closure. The anatomic site of entry-whether the corpus, lower uterine segment, or cervix-defines the tissue composition, vascularity, and contractility at the wound margins, which in turn influence how the scar remodels and withstands subsequent pregnancies. Surgical technique is also important. A robust body of experimental and clinical evidence demonstrates that restoring anatomic integrity by reapproximating uterine layers while excluding the endometrium produces stronger scars and reduces late complications. The rationale for excluding the endometrium is to prevent displacement of endometrial tissue into the myometrium and to avoid mucosal tearing against a foreign body (i.e. suture material), both of which predispose to defective healing. When the endometrium is incorporated, healing is often impaired, leading to niches or isthmoceles, adenomyosis, and endometriosis at the scar site. Over time, these defects have been recognized as contributors to abnormal bleeding, pelvic pain, infertility, uterine rupture, and placenta accreta spectrum disorders. Despite this evidence, single-layer closures that incorporate endometrium became widely adopted because of their speed and simplicity, while their long-term sequels were initially underappreciated. This has prompted renewed scrutiny of closure techniques, including comparisons of single-layer vs double-layer closure, locking vs nonlocking sutures, type of sutures, and the direction of suture. Collectively, the data show that optimal closure respects uterine anatomy, restores the natural alignment of tissues, and achieves hemostasis without compromising perfusion or strangulating tissues. Building on these principles, we herein describe a refined 3-layer closure. The first layer approximates decidua and junctional myometrium while excluding surface endometrium to prevent tissue entrapment and bacterial contamination. The second layer restores anatomic wall integrity by reapproximating the bulk of the myometrium, thereby reinforcing strength and distributing tension across the scar. The third layer reapproximates superficial myometrium and serosa, smoothing the uterine surface and reducing adhesions. This technique is not simply a return to traditional double-layer methods or an extension of single-layer practice, but rather a refinement that integrates lessons from visceral surgery and contemporary obstetric data. Its rationale is to restore anatomy, secure hemostasis without ischemia, and preserve long-term uterine function. While short-term safety appears comparable across closure methods, evidence increasingly indicates that long-term reproductive outcomes depend on how closure respects tissue biology. We argue that appropriate repair is more important than a fast repair: meticulous restoration of uterine anatomy should take precedence over operative speed. The enduring success of a hysterotomy repair depends on the surgical technique employed, as it directly affects women's future reproductive health.

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Related research

Reproductive Surgery › Uterine Surgery › Cesarean Scar Repair · Uterine and Pelvic Conditions › Acquired Uterine Conditions › Cesarean Scar Defect · Birth and Delivery › Cesarean Birth › Cesarean Recovery and Scar
Emmanuel Bujold, Roberto Romero
E Bujold, R Romero
PMID 41485855 41485855 DOI 10.1016/j.ajog.2025.10.007 10.1016/j.ajog.2025.10.007 Bujold et al. 2026, Bujold 2026