Single- versus double-layer closure of the caesarean (uterine) scar in the prevention of gynaecological symptoms in relation to niche development – the 2Close study: a multicentre randomised controlled trial

Abstract

Background Double-layer compared to single-layer closure of the uterus after a caesarean section (CS) leads to a thicker myometrial layer at the site of the CS scar, also called residual myometrium thickness (RMT). It possibly decreases the development of a niche, which is an interruption of the myometrium at the site of the uterine scar. Thin RMT and a niche are associated with gynaecological symptoms, obstetric complications in a subsequent pregnancy and delivery and possibly with subfertility. Methods Women undergoing a first CS regardless of the gestational age will be asked to participate in this multicentre, double blinded randomised controlled trial (RCT). They will be randomised to single-layer closure or double-layer closure of the uterine incision. Single-layer closure (control group) is performed with a continuous running, unlocked suture, with or without endometrial saving technique. Double-layer closure (intervention group) is performed with the first layer in a continuous unlocked suture including the endometrial layer and the second layer is also continuous unlocked and imbricates the first. The primary outcome is the reported number of days with postmenstrual spotting during one menstrual cycle nine months after CS. Secondary outcomes include surgical data, ultrasound evaluation at three months, menstrual pattern, dysmenorrhea, quality of life, and sexual function at nine months. Structured transvaginal ultrasound (TVUS) evaluation is performed to assess the uterine scar and if necessary saline infusion sonohysterography (SIS) or gel instillation sonohysterography (GIS) will be added to the examination. Women and ultrasound examiners will be blinded for allocation. Reproductive outcomes at three years follow-up including fertility, mode of delivery and complications in subsequent deliveries will be studied as well. Analyses will be performed by intention to treat. 2290 women have to be randomised to show a reduction of 15% in the mean number of spotting days. Additionally, a cost-effectiveness analysis will be performed from a societal perspective. Discussion This RCT will provide insight in the outcomes of single- compared to double-layer closure technique after CS, including postmenstrual spotting and subfertility in relation to niche development measured by ultrasound. Trial registration Dutch Trial Register ( NTR5480 ). Registered 29 October 2015. Electronic supplementary material The online version of this article (10.1186/s12884-019-2221-y) contains supplementary material, which is available to authorized users.

Effect of single‐ versus double‐layer uterine closure during caesarean section on postmenstrual spotting (2Close): multicentre, double‐blind, randomised controlled superiority trial

“…The study protocol was published before data analysis began. 19 The study was approved by the Institutional Review Board (IRB) of Amsterdam UMC, location VUmc (reg. no.…”

“…Secondary outcome measures were prespecified in the study protocol and are summarised in Table S1. 19 Serious adverse events were reported to the IRB through yearly line listing. A cost-effectiveness analysis was performed alongside the trial from a societal perspective and will be published elsewhere.…”

“…We performed this multicentre, double‐blind, randomised controlled trial at the maternity unit of 32 university, teaching and district hospitals in the Netherlands, within the Dutch Consortium for Healthcare Evaluation and Research in Obstetrics and Gynaecology. The study protocol was published before data analysis began 19 . The study was approved by the Institutional Review Board (IRB) of Amsterdam UMC, location VUmc (reg.…”

Morphological estimation of incomplete uterine scar rupture (dehiscence) in post- cesarean deliveries. Immunohistochemical studies

“…[12]. The current randomized controlled trial (2Close Study) results publication will surely help to choose the preferable technique of uterus closing during CS in relation to postmenstrual bleeding, fertility and the development of a niche, measured by ultrasound [13]. Though sonographic lower uterine segment (LUS) thickness seems to be a strong predictor for uterine scar defect and full LUS thickness of less than 2.3 mm is associated with severe complications during labor (uterine dehiscence, rupture, hemorrhage), no ideal diagnostic method can yet be recommended [14,15].…”

Reply to: Cesarean scar defect—A rising concern or a physiological healing process?

“…Our study continuously followed women to evaluate the diagnostic value of screening at 6 weeks and sought to determine a timeframe that was optimal for routine assessment of women who had undergone cesarean section. We believe that the Dutch Trial Register (NTR5480) will provide acceptable timeframes for screening of CSD.…”