Endometrium-Free Closure Technique During Cesarean Delivery for Reducing the Risk of Niche Formation and Placenta Accreta Spectrum Disorders.

Objective: To examine the prevalence and severity of postcesarean residual niche, evaluated using saline infusion sonohysterography, in an expanded cohort of women with one prior cesarean delivery and to assess the effect of uterine closure technique on the risk of placenta accreta spectrum (PAS) disorders.

Methods: This secondary analysis includes 70 patients who underwent saline infusion sonohysterography after one prior cesarean delivery. Patients were grouped according to hysterotomy closure technique: two-layer endometrium-free closure (technique A), and two- or one-layer routine closures (technique B). Niche dimensions and residual myometrial thickness were measured. The primary outcome was clinically significant niche (depth larger than 2 mm), a risk factor for PAS. Groups were compared using χ2, unpaired t test, Kruskal-Wallis, and logistic regression with significance at P<.05.

Results: There were 33 patients in the technique A group and 37 patients in the technique B group. Technique A was associated with smaller niche dimensions (P=.018 for width, .005 for depth, and .002 for length), and exhibited thicker residual myometrial thickness (8.5 mm vs 5.5 mm, P=.041) and a lower incidence of clinically significant niches. The odds of having a clinically significant niche were 27 times higher in the technique B group (adjusted odds ratio 27.1, 95% CI, 4.35-168.81, P<.001).

Conclusion: Uterine closure techniques are associated with the development and size of postcesarean residual niches, which are critical risk factors for PAS disorders. Use of an endometrium-free closure technique during primary cesarean delivery is associated with a reduced risk of future niche formation and PAS complications.