Uterine closure techniques: Historical perspective
In 1882, Max Sanger introduced a vertical uterine closure of a classical cesarean operation in response to hysterectomy as the contemporaneous alternative to prevent infection, bleeding, and death.24 Dr. Sanger emphasized layer approximation, suturing, and the avoidance of decidua in the first layer (FIGURE 2). This became the teaching of the classical CD until the 1970s. In 1926, Munro Kerr addressed uterine rupture with labor after a classical CD by introducing the lower uterine segment transverse incision. He cautioned to maintain the decidua inside the uterine 2-layer closure of the cavity.25 These pioneers were joined by others to rally for endometrium exclusion while promoting layer approximation. These techniques became universally standard and were taught across teaching medical centers in the United States and abroad until about 50 years ago.
In the 1970s, newer developments brought significant changes to uterine closure techniques. Initiated by Joel-Cohen,26 blunt dissection of the abdominal incision was adapted by Michael Stark, creating what came to be known as the Misgav-Ladach cesarean technique.27 Stark emphasized blunt dissection and introduced single-layer closure. Thereby the exclusion of the endometrium, used for more than 70 years, was abandoned by the present-day single- or double-layer uterine closure in favor of cost and time savings. Systematic reviews and meta-analyses comparing the two contrasting techniques were inconclusive, noting that the niche prevalence and size were similar in both groups. These studies did not take into account the variety of individual techniques or the position of the endometrium in the final closures.28
Endometrium and uterine closure
Our recent study examining uterine scar defect in women after one primary CD by SIS concluded that a specific endometrium-free closure technique (EFCT) (FIGURE 3) is associated with fewer and less severe defects and a thicker residual myometrial thickness when compared with closures with unknown or endometrium inclusion.29 The study found non-specific closure techniques to be 6 times more likely to form a niche of 2-mm deep or greater than the EFCT.
Furthermore, we surveyed the diversity of uterine closures and the location of the endometrium among obstetricians in one institution.30 Presence of endometrium on the surface of the final uterine closure was reported by 20% of respondents (see Figure 1). When asked for their opinion on the impact of CD techniques on placenta accreta spectrum, without available evidence 80% of the survey respondents reported no relationship to techniques, and only 20% suggested an association. This particular study demonstrates that the surgical techniques just described are random, unfettered, and applied without consideration of clinical outcomes.
Our recent retrospective study that spanned 30 years and examined the EFCT—performed anywhere between 3 to 9 consecutive CDs—revealed no abnormal placentation in any subsequent pregnancies.31 This was one of the few clinical studies of the long-term consequences of a uterine closure technique. In this study, the endometrium was excluded during the uterine closure, allowing its free edges to abut and heal. This step avoids scarring the endometrial-myometrial (EM) interface and unintentional inclusion of endometrium in the closed uterine wall. In this context, Jauniaux and colleagues cited the destruction of the EM interface as the main factor for placenta-adherent disorders.32 Sholapurkar and others highlight the need to further examine intrinsic details of uterine closure beyond single- and double-layer techniques to better understand the etiology of cesarean scar formation.19 The search for the pathophysiology of CSN continues to present significant challenges imposed by the variety of currently practiced uterine closures.
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