Three-Layer Anatomical Uterine Closure versus Conventional Two-Layer Closure for Early Cesarean Scar Sonographic Morphology: A randomized controlled trial
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Abstract
Objectives: To compare early cesarean scar morphology between three-layer anatomical uterine closure and conventional two-layer closure, using the residual-to-adjacent myometrial thickness ratio (RMT/AMT) at 6 weeks postpartum as the primary outcome.
Materials and Methods: In this randomized controlled trial, 60 women undergoing primary cesarean delivery were assigned 1:1 to either a conventional two-layer group or a three-layer anatomical closure group, with randomization stratified by elective or emergency cesarean delivery. Transvaginal ultrasound was performed at 6 weeks postpartum by a blinded examiner. The primary outcome was the RMT/AMT ratio. Secondary outcomes included residual myometrial thickness, adjacent myometrial thickness, niche depth, niche length, niche depth/AMT ratio, niche presence, operative time, and estimated blood loss.
Results: All 60 participants received the allocated intervention, and sonographic outcomes were available for 56 participants (28 per group). The median RMT/AMT ratio was higher with three-layer anatomical closure than with conventional two-layer closure (0.800 [interquartile range, IQR 0.716, 1.000] vs 0.708 [IQR 0.604, 0.783], p = 0.007). Median niche depth was lower (2.4 [IQR 0, 3.1] vs 3.2 [IQR 2.55, 4.4] mm, p = 0.017), as was the median niche depth/AMT ratio (0.173 [IQR 0, 0.227] vs 0.234 [IQR 0.142, 0.318], p = 0.045). Median operative time was longer in the three-layer group (37 [IQR 33, 43] vs 33 [IQR 30, 36] minutes, p = 0.035), whereas estimated blood loss did not differ significantly between groups.
Conclusion: Three-layer anatomical uterine closure was associated with a higher RMT/AMT ratio and lower niche depth and niche depth/AMT ratio at 6 weeks postpartum than conventional two-layer closure. Operative time was slightly longer with the three-layer technique, whereas estimated blood loss did not differ significantly between groups. Longer-term studies are needed to determine the clinical significance of these early sonographic differences.
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