Impact of uterine closure on residual myometrial thickness after cesarean: a randomized controlled trial

Contrast Hysterosonographic Evaluation of Niche Prevalence Following a Standardized Suturing Technique for Caesarean Sections

Introduction

After caesarean section a uterine niche can be detected in 42-84% of all women and in 11-45% large defects with a residual myometrium < 2.2 mm occur. If the niche compromises > 50% of myometrial thickness, risk of uterine rupture during birth increases. The suturing technique might contribute substantially on pathogenesis of niches. The objective of this study is to investigate the effect of the suturing technique on niche prevalence by using a standardized two-layer surgical technique.

Methods

Women with one previous caesarean section were examined within 6-23 months after caesarean section using contrast medium-supported transvaginal sonography regarding the prevalence, sonomorphological aspect and clinical symptoms of a uterine niche. The surgical technique used was: dilatation of the cervix, interrupted suture of the first layer (excluding the endometrium), continuous closure of the visceral and parietal peritoneum.

Results

Using native vaginal sonography, no niches were visible in the whole cohort. In three cases, there was a small niche detectable with a depth between 2.3 and 3.9 mm by contrast hysterosonography. Regarding the total myometrial thickness, the niche depth compromised less than 50%. All patients were symptom-free.

Conclusion

In our study population, there were only three cases (9.1%) with a small uterine niche. Residual myometrium and niche percentage on myometrial thickness were excellent in all three cases. Thus, our results show that the uterotomy closure technique used in the study cohort might be superior with respect to the development of uterine niches compared with the expected prevalence.

Effects of endometrial versus non-endometrial suturing on isthmocele development; a randomized controlled trial

OBJECTIVE

Incomplete healing after cesarean section (CS) can result in isthmocele formation. When suturing the uterus, fully folding the wound lips may embed the endometrial layer into the myometrium, leading to isthmocele development. Hence, this study aimed to compare the effects of endometrial and non-endometrial suturing on isthmocele development.

MATERIAL AND METHODS

This randomized controlled trial included 274 patients. Women who underwent primary CS were randomly allocated to one of the two study groups: endometrial suturing and non-endometrial suturing. The primary outcome was isthmocele rate at postpartum 6 months. Secondary outcomes were the volume of the isthmocele, thickness of the residual myometrium, menstrual irregularities (intermenstrual spotting), and the relationship between the isthmocele and uterine position.

RESULTS

A total of 159 patients (81 in the endometrial suturing group and 78 in the non-endometrial suturing group) were analyzed. The incidence of isthmocele was significantly lower in the non-endometrial suturing group than in the endometrial suturing group (12 [15.4%] vs. 24 [29.6%] patients; p = 0.032). Menstrual irregularities, such as intermenstrual spotting, were significantly higher in the endometrial suturing group than in the non-endometrial group (p = 0.019).

CONCLUSION

Uterine closure with non-endometrial suturing was associated with significantly lower isthmocele development and less intermenstrual spotting compared to that with endometrial suturing.

The Novel Parallel Closure Technique Compared to Single-Layer Closure of the Uterus After Primary Cesarean Section Decreases the Incidence of Isthmocele Formation and Increases Residual Myometrial Thickness

Background Isthmocele or a scar defect is a relatively common consequence of cesarean section resulting in menstrual disturbances and infertility and may compromise the myometrial integrity of the uterus in women contemplating subsequent vaginal birth. Several preventive measures have been suggested, including the modification of surgical techniques used for the closure of the uterine incision. The current study aimed to compare the incidence of isthmocele and assess residual myometrial thickness in women who underwent single versus parallel layered closure to approximate the endo-myometrial layer during cesarean section. Methodology This retrospective study evaluated data of women undergoing their first cesarean section under elective conditions (n = 497) where the uterine incision was closed using a single (n = 295) or a parallel layer (n = 202) technique. Patients were evaluated twice, at 3-6 months and 18 months postpartum, with a transvaginal ultrasound noting the presence or absence of an isthmocele and measurement of the residual myometrial thickness. Results Regardless of the closure technique, 64 (12.9%) women had an ultrasound-diagnosed isthmocele. Significantly fewer patients in the parallel-layer closure group presented with an isthmocele both at 3-6 (13.6 vs. 6.9%; p = 0.019) and 18 months (16.3 vs. 7.8%; p = 0.009) postpartum. Residual myometrium was significantly thicker in the parallel-layer closure group (8.0 vs. 13.2 mm at 3-6 months postpartum; p = 0.000 and 7.2 vs. 12.3 mm at 18 months postpartum; p = 0.004). For all patients, a retroverted position of the uterus at 3-6 months follow-up examination significantly increased the frequency of isthmocele (36/395 (9.1%) with an anteverted uterus and 18/102 (17.6%) with a retroverted uterus; p = 0.002). In patients with a single-layer closure, a retroverted uterus at the 3-6-month follow-up was associated with an isthmocele in 29.5% (18/61) of patients, while no isthmocele was recorded when the uterus was retroverted in the parallel-layer closure group (0/41) (p = 0.001). At 18 months postpartum, of the 64 patients with an isthmocele, 26 (40.6%) presented with abnormal uterine bleeding mainly in the form of postmenstrual spotting. Of the 26 patients with abnormal bleeding, 23 were in the single-layer and three were in the parallel-layer closure group. Conclusions The parallel-layer closure when compared to a single-layer closure of the uterine incision in patients undergoing primary cesarean section decreased the incidence of isthmocele formation and increased residual myometrial thickness. More patients in the single-layer closure group had menstrual cycle disturbances at 18 months postpartum.

A morphological study of symptomatic uterine niche using three-dimensional models from thin-slice magnetic resonance imaging

RESEARCH QUESTION

Is there a correlation between various morphological parameters of the uterine niche and post-menstrual spotting using three-dimensional models from thin-slice (1 mm) magnetic resonance imaging (MRI)?

DESIGN

This study retrospectively identified women diagnosed with a symptomatic niche by thin-slice MRI between December 2019 and December 2021. Univariable and multivariable linear regression models assessed the correlations between morphological parameters and the duration post-menstrual spotting. Morphological differences of the niche formed by one versus two Caesarean sections were analysed by univariable and multivariable logistic analysis.

RESULTS

A total of 205 women diagnosed with symptomatic niche were included in the study. The niche among most women with post-menstrual spotting was ellipsoidal, with width greater than length greater than depth, from which niche volume was estimated based on manual measurements (volume = 0.520 × length × width × depth). Manually calculated niche length (β = 0.257, 95% confidence interval [CI] 0.040-0.473, P = 0.020) and radiomically assessed minor axis length (β = 0.329, 95% CI 0.009-0.795, P = 0.045) both positively correlated with the duration of post-menstrual spotting, whereas the distance between the niche and external os (β = -0.120, 95% CI -0.202 to -0.038, P = 0.004) was inversely correlated. Women with two Cesarean sections reported more days of post-menstrual spotting (8.76 ± 3.54 versus 6.68 ± 3.90 days, P < 0.001) and had increased niche length diameter (adjusted odds ratio [aOR] 1.304, 95% CI 1.190-1.429) and a smaller surface-area-to-volume ratio (aOR 0.296, 95% CI 0.129-0.680).

CONCLUSIONS

Niche-associated post-menstrual spotting correlates with the length diameter of the niche and the distance between the niche and external os. Niches in women after two Caesarean sections tend to be longer in length diameter and more spherical.

Clinical Risk Factors for Placenta Accreta or Placenta Percreta: A Case-Control Study

OBJECTIVES

Uterine scarring is a risk factor for placenta accreta spectrum (PAS) disorder. We aimed to determine the factors related to PAS in women who had previously undergone a cesarean.

METHODS

We performed a case-control study where women who underwent postpartum hysterectomy for placenta accreta/percreta (cases) were matched to all women with a previous cesarean who delivered in the week before each case (controls). Maternal characteristics along with previous cesarean characteristics were compared between cases and controls. Univariate and multivariate logistic regression analyses were performed to determine risk factors related to PAS.

RESULTS

We compared 64 cases of PAS that required hysterectomy to 192 controls. The factors related to PAS were a history of uterine surgery (OR 27.4; 95% CI 5.1-146.5, P < 0.001) and the number of previous cesareans (2 cesareans: OR 7.2; 95% CI 3.4-15.4, P < 0.001; more than 2 cesareans: OR 7.9; 95% CI 2.9-21.5, P < 0.001). In women with a single previous cesarean without previous uterine surgery, an interdelivery interval of fewer than 18 months (OR 6.3; 95% CI 1.8-22.4, P = 0.004) and smoking (OR 5.8; 95% CI 1.2-27.8, P = 0.03) were related to PAS. The gestational age and the cervical dilatation at previous cesarean were not associated with PAS (all with P > 0.05). The lack of data regarding the closure of the uterus at previous cesareans prevents us from drawing solid conclusions.

CONCLUSIONS

Previous uterine surgery, the number of previous cesareans, smoking, and an interdelivery interval of fewer than 18 months after cesarean are significant risk factors for PAS requiring postpartum hysterectomy.

Near-infrared and hysteroscopy-guided robotic excision of uterine isthmocele with laser fiber: a novel high-precision technique

OBJECTIVE

To describe a novel high-precision technique for robotic excision of uterine isthmocele, employing a carbon dioxide laser fiber, under hysteroscopic guidance, and near-infrared guidance.

DESIGN

Video article.

PATIENT(S)

A 36-year-old multipara with 3 prior cesarean sections presented to our infertility clinic with secondary infertility. The patient had been trying to conceive for 6 months without success. The patient underwent a hystero-salpingo contrast sonography that identified a large cesarean scar defect with a 1.4-mm residual myometrial thickness (RMT). The patient was counseled on surgical management with robotic approach because of RMT <3 mm precluding her from hysteroscopic resection and the potential risk for a cesarean scar ectopic or abnormal placentation if she were to become pregnant in the future. She elected to undergo excision and repair and informed consent was obtained from the patient.

INTERVENTION(S)

The robot was docked for traditional gynecologic robotic surgery. The uterus was injected with 5 units of vasopressin. We used a carbon dioxide laser fiber (Lumenis FIberLase) at a power of 5 watts as the sole energy source for dissection. The bladder was dissected off the uterus to identify the general area of the isthmocele. At that point, diagnostic hysteroscopy was performed using a 30-degree 5-mm hysteroscope (Karl Storz) to identify and enter the isthmocele. Near-infrared vision (da Vinci Firefly, Intuitive USA) was activated to precisely outline the extent of the isthmocele, which was not visible with simple transillumination from the hysteroscope. We proceeded with laser excision in infrared/gray scale using the laser at a power of 20 watts removing the entire area that was highlighted by the Firefly. After full excision of the isthmocele, the hysteroscope was removed and was eventually replaced by a uterine manipulator (ConMed VCare DX). The hysterotomy was closed with a 2-layer closure: 4 mattress sutures of 2-0 Vicryl (Ethicon) followed by a running 2-0 PDS Stratafix (Ethicon). The peritoneal layer was closed over these 2 layers with 2-0 PDS Stratafix (Ethicon) in a running fashion. The uterine manipulator was removed and a 14 French Malecot catheter (Bard) was placed in the uterine cavity to allow the healing to proceed with minimal risk of cervical stenosis. The bladder was backfilled to ensure integrity of the bladder wall. Interceed adhesion barrier (Gynecare) was then placed over the area of the repair and the procedure was concluded. The patient included in this video gave consent for publication of the video and posting of the video online including social media, the journal website, scientific literature websites (such as PubMed, ScienceDirect, Scopus, etc.), and other applicable sites.

MAIN OUTCOME MEASURE(S)

Completion of excision and repair of cesarean scar defect without surgical complications.

RESULT(S)

Robotic excision and repair of a sizable uterine isthmocele with carbon dioxide laser fiber and da Vinci Firefly was completed successfully without any surgical complications. Diagnostic hysteroscopy was used to positively identify the isthmocele and provide transillumination. However, the thickness of the cervical myometrium only allows the hysteroscopic light to shine through the thinnest portion of myometrium at the apex of the isthmocele, whereas the near-infrared vision allowed by the da Vinci Firefly technology was used to precisely identify the borders of the defect. The carbon dioxide laser was used to completely remove the defect while avoiding damage to delicate reproductive tissue and over-excision. No complications were identified during the postoperative visit. Magnetic resonance imaging 3 months after the surgery revealed an RMT of 10 mm at the location of excision compared with the initial RMT of 1.4 mm.

CONCLUSION(S)

Currently, there is no gold-standard technique for surgical management of isthmocele. This is the first description of the combined use of hysteroscopy, near-infrared vision, and laser fiber for the robotic excision of isthmocele. This specific setup proves to be a useful technical improvement. The use of near-infrared vision combined with precise hysteroscopic targeting allows much clearer definition of he isthmocele borders, and the flexible laser fiber allows millimetric xcision in the absence of appreciable lateral thermal spread. Further investigation is warranted to identify a gold-standard surgical technique for patients with cesarean scar defect.

Intra-operative Guidelines for the Prevention of Uterine Niche Formation in Cesarean Sections: A Review

Formation of a uterine niche following a C-section can predispose the patient to future obstetric complications such as dehiscence, uterine rupture, ectopic pregnancy, and placenta accreta. The significant morbidity and mortality of these complications along with increasing C-section rates emphasizes the importance of prevention. However, there are no clear guidelines on intra-operative protocol to prevent postpartum niche formation. Besides surgical technique, the novel use of platelet-rich plasma (PRP) and mesenchymal stem cell (MSC) injections has demonstrated promising potential and may have applications in hysterotomy closures. The objective is to examine current research on optimal C-section procedures to prevent uterine niche formation and subsequent obstetric complications. A systematic review was conducted using PubMed and Google Scholar. Initial searches yielded 827 results. Inclusion criteria were human, animal, and in-vitro studies, peer-reviewed sources, and outcomes pertinent to the uterine niche. Exclusion criteria applied to articles with outcomes unrelated to myometrium and interventions outside of the intra-operative and immediate pre-/post-operative period. Based on the criteria, 41 articles were cited. Pathophysiology of uterine niche formation was associated with incisions through cervical tissue, adhesion formation, and poor approximation. Significant risk factors were low uterine incisions, advanced cervical dilatation, low station, non-closure of the peritoneum, and creation of a bladder flap. There was no consensus on uterine closure as it likely depends on surgical proficiency with the given technique, but a double-layered non-locking suture appears reliable to reduce niche severity. Recent trials indicate that intra-operative PRP/MSC injections may decrease niche incidence and severity, but more research is needed. If prevention or minimization of uterine niche is desired, the optimal C-section protocol should avoid low uterine incisions, choose uterine closure technique based on the surgeon's proficiency (double-layered non-locking is reliable), and close the peritoneum, and myometrial injection of PRP/MSC may be a useful adjunct intervention pending further clinical evidence.

Aetiology, risk factors and preventive strategies for niche development: A review

The increase in caesarean sections (CS) has resulted in an increase in women with a uterine niche. The exact aetiology of niche development has yet to be elucidated but is likely multifactorial. This study aimed to give a systematic overview of the available literature on histopathological features, risk factors and results of preventive strategies on niche development to gain more insight into the underlying mechanisms. Based on current published data histopathological findings associated with niche development were necrosis, fibrosis, inflammation, adenomyosis and insufficient approximation. Patient-related risk factors included multiple CS, BMI and smoking. Labour-related factors were CS before onset of labour, extended cervical dilatation, premature rupture of membranes and presenting part of the fetus at CS below the pelvic inlet. Preventive strategies should focus on the optimal level of incision, training of surgeons and full-thickness closure of the myometrium (single or double-layer) using non-locking sutures. Conflicting data exist concerning the effect of endometrial inclusion. Future studies without heterogeneity in population, using standardized performance of the CS after proper training and using standardized niche evaluation with a relevant core outcome set are required to allow meta-analyses and to develop evidence-based preventive strategies. These studies are needed to reduce the prevalence of niches and prevent complications in subsequent pregnancies such as caesarean scar pregnancies.

Cesarean scar disorder: Management and repair

Cesarean scar disorder (CSD) is an entity recently defined as uterine niche with at least one primary or 2 secondary symptoms. CSDs can be visualized by hysterosalpingography, transvaginal sonography, saline infusion sonohysterography, hysteroscopy, and magnetic resonance imaging, but diagnosis should be performed by exams able to measure the residual myometrial thickness (RMT). Although there is a limited number of studies evaluating fertility and reproductive outcomes after different types of surgery, the following consideration should be kept in mind. Asymptomatic women should not be operated with the hope of improving obstetrical outcomes. It is reasonable to consider hormone therapy for CSDs as a symptomatic treatment in women who no longer wish to conceive and have no contraindications. In case of failure of or contraindications to medical treatment, surgery should be offered according to the severity of symptoms, including infertility, the desire or otherwise to preserve the uterus, the size of the CSD, and RMT measurement. Hysteroscopy is considered to be more of a resection than a repair, so women who desire pregnancy should be excluded from this technique in case of RMT <3 mm. In this instance, repair is essential and can only be achieved by a laparoscopic or vaginal approach. The benefit of laparoscopic approach seems to persist after subsequent CS. Women with CSDs need to be given complete information, including available literature, before any treatment decision is made.

Impact of purse-string uterine suture on scar healing after a cesarean delivery: a randomized controlled trial

BACKGROUND

Uterine closure technique can affect scar healing, potentially resulting in unfavorable gynecologic and life-threatening obstetrical outcomes. Double-layer continuous unlocked suture has been demonstrated to promote optimal residual myometrial thickness. Recently, the purse-string uterine suture technique has emerged as a viable method to enhance the healing of scars. However, the current lack of randomized trials assessing the relevance of this technique warrants further investigation.

OBJECTIVE

This study aimed to evaluate the impact of purse-string uterine sutures on scar healing after cesarean delivery when compared with double-layer continuous unlocked suture.

STUDY DESIGN

This was a randomized controlled trial; 126 patients with singleton pregnancies undergoing primary cesarean delivery were enrolled in 2 groups. The primary outcome was the mean residual myometrial thickness measured by saline infusion sonography 6 months after surgery by 2 sonographers blinded to uterine closure techniques. Operative time, calculated blood loss, total number of needed threads, and perioperative scar width were used for the perioperative analysis. Healing ratio and cesarean scar defect measurements were used for the 6-month analysis.

RESULTS

There was no significant difference in terms of residual myometrial thickness (9.38±2.3 vs 8.4±3.9 mm; P=.187), blood loss (540 [146-982] vs 495 [241-903] mL; P=.815), or operative time (6.2 [5.2-7] vs 6 [5.3-7] minutes; P=.977). Achievement of purse-string uterine suture required significantly fewer threads (1 [1-1] vs 2 [1-2]; P<.001) and fewer hemostatic complementary sutures (1 [1-1] vs 1 [1-2]; P=.013). Scar width was significantly lower with purse-string uterine sutures (50 [40.5-50.5] vs 70 [60-70.5] mm; P<.0001). Purse-string uterine sutures allowed a higher healing ratio (1 [0.9-1] vs 0.84 [0.59-1]; P=.003) and significantly fewer cesarean scar defects (12% vs 35%; P=.018) compared with double-layer continuous unlocked suture.

CONCLUSION

Despite resulting in no difference in residual myometrial thickness, purse-string uterine closure seems to be associated with better uterine scar healing on the basis of a higher healing ratio, and a lower rate of cesarean scar defects compared with double-layer continuous unlocked suture.

Prognostic model on niche development after a first caesarean section: development and internal validation

OBJECTIVE

To develop and internally validate a prognostic prediction model for development of a niche in the uterine scar after a first caesarean section (CS).

STUDY DESIGN

Secondary analyses on data of a randomized controlled trial, performed in 32 hospitals in the Netherlands among women undergoing a first caesarean section. We used multivariable backward logistic regression. Missing data were handled using multiple imputation. Model performance was assessed by calibration and discrimination. Internal validation using bootstrapping techniques took place. The outcome was 'development of a niche in the uterus', defined as an indentation of ≥ 2 mm in the myometrium.

RESULTS

We developed two models to predict niche development: in the total population and after elective CS. Patient related risk factors were: gestational age, twin pregnancy and smoking, and surgery related risk factors were double-layer closure and less surgical experience. Multiparity and Vicryl suture material were protective factors. The prediction model in women undergoing elective CS revealed similar results. After internal validation, Nagelkerke R² ranged from 0.01 to 0.05 and was considered low; median area under the curve (AUC) ranged from 0.56 to 0.62, indicating failed to poor discriminative ability.

CONCLUSIONS

The model cannot be used to accurately predict the development of a niche after a first CS. However, several factors seem to influence scar healing which indicates possibilities for future prevention such as surgical experience and suture material. The search for additional risk factors that play a role in development of a niche should be continued to improve the discriminative ability.

Double-layered purse string uterine suture compared with single-layer continuous uterine suture: A randomized Controlled trial

BACKGROUND

With the aim of preventing cesarean scar defects, we introduced a new technique involving a purse string uterine suture. To date, this uterine suture technique has not been formally evaluated. The objective of the study was to test the hypothesis that compared to single layer continuous uterine suture (SLCUS), a double layered purse string uterine suture (PSUS) significantly reduces cesarean scar defect (CSD) rates, without increasing the perioperative maternal morbidity.

METHODS

A prospective randomized study. Primary outcome was the rate of CSD. 100 patients were enrolled in 2 groups according to the uterine suture technique. A hysterosonography was performed by the same senior obstetrician blinded to the uterine suture technique 6 months after surgery .Operative time and calculated blood loss (CBL) were used for the short time analysis. Uterine and CSD measurements were used for the mid time analysis.

RESULTS

Despite a longer operative time with PSUS (7.17 ± 2.31 min Vs. 6.31 ± 3.04 min, p = 0.028; p <10‾³); there was no significant difference in terms of CBL (520 ± 58 with PSUS vs. 536 ± 50 ml, p = 0.724). There was a significant decrease in the rate of CSD with PSUS: 6.66% Vs.40% with SLUCS; p<0.001. Moreover, SLUCS was the leading risk factor for CSD: adjusted OR=6; 95% CI [0-1], p<10‾³).

CONCLUSION

Compared to single layer continuous suture, double layered purse stringuterine suture significantly reduces cesarean scar defect rates, without increasing the perioperative maternal morbidity.

Scar Tissue after a Cesarean Section-The Management of Different Complications in Pregnant Women

The definition of a cesarean scar pregnancy (CSP) is the localization of the gestational sac (GS) in the cicatrix tissue, which is created in the front wall of the uterus after a previous cesarean section (CS). The worldwide prevalence of CSP has been growing rapidly. However, there are no general recommendations regarding prophylaxis and treatment of the abnormalities of the anterior wall of the uterus discovered in a non-pregnant myometrium, or how to deal with existing cases of CSP. We present the latest knowledge, a holistic approach to the biology, histology, imaging, and management concerning post-CS scars based on our cases, which were treated in the Department of Pregnancy and Pathology of Pregnancy in the Medical University of Lublin, Poland. In our study, we present images of tissue samples of areas with a cicatrix in the uterus, and ultrasound and MRI images of CSP. We discuss the advances in the biology of the post-CS scar tissue, the prevention techniques used to repair the scar defect (niche) before the pregnancy, and the treatment of different complications of CSP, such as the rupture of the gravid uterus or the dehiscence of the myometrium.

Single- Versus Double-Layer Uterine Closure After Cesarean Section Delivery: A Systematic Review and Meta-Analysis

Cesarean section (CS) delivery is a common procedure, and its incidence is increasing globally. To compare single-layer (SL) with double-layer (DL) uterine closure techniques after cesarean section in terms of ultrasonographic findings and rate of CS complications. PubMed, Scopus, Web of Science, and Cochrane Library were searched for relevant randomized clinical trials (RCTs). Retrieved articles were screened, and relevant studies were included in a meta-analysis. Continuous data were pooled as mean difference (MD) with 95% confidence interval (CI), and dichotomous data were pooled as relative risk (RR) and 95% CI. Analysis was conducted using RevMan software (Version 5.4). Eighteen RCTs were included in our study. Pooled results favored DL uterine closure in terms of residual myometrial thickness (MD = -1.15; 95% CI -1.69, -0.60; P < 0.0001) and dysmenorrhea (RR = 1.36; 95% CI 1.02, 1.81; P = 0.04), while SL closure had shorter operation time than DL closure (MD = -2.25; 95% CI -3.29, -1.21; P < 0.00001). Both techniques had similar results in terms of uterine dehiscence or rupture (RR = 1.88; 95% CI 0.63, 5.62; P = 0.26), healing ratio (MD = -5.00; 95% CI -12.40, 2.39; P = 0.18), maternal infectious morbidity (RR = 0.94; 95% CI 0.66, 1.34; P = 0.72), hospital stay (MD = -0.12; 95% CI -0.30, 0.06; P = 0.18), and readmission rate (RR = 0.95; 95% CI 0.64, 1.40; P = 0.78). Double-layer uterine closure shows more residual myometrial thickness and lower incidence of dysmenorrhea than single-layer uterine closure of cesarean section scar. But single-layer closure has the advantage of the shorter operation time. Both methods have comparable blood loss amount, healing ratio, hospital stay duration, maternal infection risk, readmission rate, and uterine dehiscence or rupture risk.

A new technique for uterine incision closure at the time of cesarean section: does it make a difference?

The purpose of this study was to compare the short-term operative outcomes of three different surgical techniques for uterine incision closure during caesarean section (CS). This trial enrolled 120 patients scheduled for primary caesarean delivery. Patients were randomised into either classical double-layer uterine closure, purse-string double-layer uterine closure (Turan), or our new approach of uterine closure (double layer step up-step down technique). For short-term comparison, transvaginal ultrasonography was planned for all patients 6 weeks after surgery. Compared to group II and Group III, residual myometrial thickness was significantly thinner in group I (p < .001). The number of patients with uterine niche was 10 (50% of all scar defects) in group I whereas it was 4 (20%) in group II and 6 (30%) in group III. Operative time was significantly longer in group II (p < .001). This led to our conclusion that Turan technique and our new approach are associated with thicker myometrial thickness and less frequency of uterine scar defect than classical double-layer uterine incision closure; however, our approach takes less operative time. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT04681378Impact statementWhat is already known on this subject? Many variations in CS technique have been studied. For example, single-layer uterine incision closure has been compared to double-layer uterine incision closure. Purse string double layer (Turan) has been also compared to the traditional double-layer technique. Double layer unlocked closure has been shown to result in a thicker residual myometrium and as a consequence can possibly lead to the decrease of niche development after a CS compared to single-layer closure with lower frequency of uterine scar defect with Turan technique.What do the results of this study add? Here we introduce a new uterine closure technique, which we have named double-layer step up-step down technique, as an alternative method. With this technique, the uterine incision contract more than with the traditional double layer technique and has similar results to the Turan technique; however, our approach takes less operative time.What are the implications of these findings for clinical practice and/or further research? These alternative techniques of uterine incision closure decrease the frequency of uterine niche that may be associated with many clinical problems such as ectopic pregnancy at the CS scar, placenta accreta, rupture of the uterus during a subsequent pregnancy. Future studies are needed to investigate the frequency of uterine rupture in a subsequent pregnancy following different uterine incision closure techniques.

Babu and Magon uterine closure technique during cesarean section: A randomized double-blind trial

AIM

We compared the effectiveness of the Babu and Magon uterine closure technique and unlocked double-layer uterine closure on the integrity and thickness of the uterine scar.

METHODS

A randomized double-blind trial was performed at Hazrat-e Rasoul -e-Akram Hospital, Tehran, Iran, from March 2018 to December 2019, in 72 pregnant women who were candidates for cesarean section for the first time. Women were randomly assigned to the Babu and Magon uterine closure technique (intervention group, n = 34) or double-layer closure of the uterine incision (control group, n = 38). The primary outcome of the study was the frequency of myometrial defects at the site of the scar (niche), and a large niche. Secondary outcomes, including the time taken for uterine closure and postpartum hemorrhage (early and late), were compared between groups.

RESULTS

Adjacent myometrium thickness (AMT) between the two groups was not statistically significant. A niche was reported in 23.5% (8/34) and 50% (19/38) of women in the intervention and controls, respectively (p = 0.02). A large niche was reported in 2.9% (1/34) and 23.7% (9/38) of women in the intervention and controls, respectively (p < 0.01). The duration of uterine closure was not statistically significant between the two groups. Hemoglobin levels did not differ significantly between groups during the first 24 h post-surgery.

CONCLUSION

The results of the study showed that the technique of uterine closure is one of the main potential determinants of myometrial healing. The Babu and Magon uterine closure technique seems to lead to tissue alignment during suturing and consequently cause better myometrial healing, although this issue calls for well-founded longer studies of appropriate design.

The effect of the onset of labor on the characteristics of the cesarean scar

OBJECTIVE

To assess the effect of cesarean section (CS) timing, elective versus unplanned, on the residual myometrial thickness (RMT) and CS scars.

METHODS

This is a prospective single-blinded observational cohort study with 186 observations. Patients indicated to undergo first singleton CS were preoperatively recruited. Exclusion criteria were history of repeated CS, vertical hysterotomy, diabetes, and additional uterine surgeries. Sonographic examination was performed for assessing the RMT ratio, the presence of a niche, fibrosis, and the distance from the scar to the internal os (SO) 1 year after CS. Power analysis was performed with 0.05 α, 0.1 β, and all statistical analyses were conducted with Stata^® .

RESULTS

Wilcoxon rank-sum test for the association between CS timing, RMT ratio and SO showed Z values of -0.59 and -4.94 (P = 0.553 and P < 0.001), respectively. There was no association between CS timing and niches and fibrosis (P > 0.99 and P = 0.268, respectively). Linear regression between SO and the extent of cervical dilatation showed a -0.45 β (95% confidence interval -0.68 to -0.21) and a 10.22-mm intercept (P < 0.001).

CONCLUSION

RMT is independent of the timing of CS, but the SO distance shows a negative linear relationship with the cervical dilatation.

Potential risk factors for caesarean scar pregnancy: a retrospective case-control study

STUDY QUESTION

What are the important risk factors for having a caesarean scar pregnancy (CSP)?

SUMMARY ANSWER

Independent risk factors were smoking in the first trimester, higher parity, and previous caesarean section (CS) before the index caesarean delivery.

WHAT IS KNOWN ALREADY

A spectrum of risk factors for CSP has been suggested but not proven: parity, number of previous caesarean section, elective as opposed to emergency CS, IVF-pregnancy, breech presentation, previous gynaecological surgery as well as suture technique.

STUDY DESIGN SIZE DURATION

This retrospective case-control study included 31 women with a CSP during the period 2003-2018 treated at a tertiary care centre for gynaecology and reproduction. A control cohort of 8300 women with a history of a CS and a subsequent delivery during the same time period was formed.

PARTICIPANTS/MATERIALS SETTING METHODS

Variables describing demography, lifestyle factors, and reproductive and obstetric history were retrieved from medical records and the obstetric hospital database. Logistic regression analyses were applied to identify potential risk factors.

MAIN RESULTS AND THE ROLE OF CHANCE

In a multivariable analysis, smoking in first trimester (adjusted odds ratio (OR) 3.03, 95% CI 1.01-9.07), higher parity (adjusted OR 1.30, 95% CI 1.03-1.64) and previous CS in addition to the preceding CS (adjusted OR 3.43, 95% CI 1.35-8.66) were independently predictive of a CSP. An elective CS at the index pregnancy was associated with an increased risk of CSP but did not remain significant in the multivariable analysis.

LIMITATIONS REASONS FOR CAUTION

CSP is a very rare phenomenon and several of the risk factor estimates are imprecise. Nevertheless, significant risk factors could be identified. Another limitation is the lack of electronically recorded details on suture techniques.

WIDER IMPLICATIONS OF THE FINDINGS

The identified factors, namely higher parity and previous CS before the index caesarean section, are in accordance with previously suggested risk factors. Whether there is a true risk association between elective CS and future CSP needs to be investigated further. Smoking in the first trimester is a new finding, which has a plausible rationale. These factors should be recognised when counselling women after a caesarean delivery, particularly in a subsequent pregnancy with early complications.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by a grant from the Swedish state under the agreement between the Swedish government and the county councils the ALF-agreement (ALFGBG-720291). None of the authors has any conflict of interest to declare.

The Case for Standardizing Cesarean Delivery Technique: Seeing the Forest for the Trees

In this Commentary, we explain the case for a standardized cesarean delivery surgical technique. There are three strong arguments for a standardized approach to cesarean delivery, the most common major abdominal surgery performed in the world. First, standardization within institutions improves safety, efficiency, and effectiveness in health care delivery. Second, surgical training among obstetrics and gynecology residents would become more consistent across hospitals and regions, and proficiency in performing cesarean delivery measurable. Finally, standardization would strengthen future trials of cesarean delivery technique by minimizing the potential for aspects of the surgery which are not being studied to bias results. Before 2013, more than 155 randomized controlled trials, meta-analyses or systematic reviews were published comparing various aspects of cesarean delivery surgical technique. Since 2013, an additional 216 similar studies have strengthened those recommendations and offered evidence to recommend additional cesarean delivery techniques. However, this amount of cesarean delivery technique data creates a forest for the trees problem, making it difficult for a clinician to synthesize this volume of data. In response to this difficulty, we propose a comprehensive, evidence-based and standardized approach to cesarean delivery technique.

Single- or double-layer uterine closure techniques following cesarean: A randomized trial

INTRODUCTION

Cesarean deliveries are commonly performed throughout the world. Although the uterine closure technique following this procedure may influence how the uterine scar heals, there is insufficient evidence for choosing the appropriate technique and so preventing long-term negative consequences. This prospective, randomized study examined the effects of single- and double-layer uterine closure techniques on uterine scar healing following cesarean delivery.

MATERIAL AND METHODS

This study assessed a total of 282 women aged 18-45 years who were in gestational weeks 24-41 of singleton pregnancies. None had previously undergone uterine surgeries. These participants completed their first cesarean deliveries at the time of study and were randomized into the following two treatment groups: single-layer closure with locking and double-layer closure with locking in the first layer, but not in the second layer (NCT03629028). However, the decidua was not included for treatment in either group. Participants were evaluated at 6-9 months after cesarean section by saline infusion sonohysterography to assess cesarean delivery scar defects. These procedures were conducted by experienced sonographers who were not aware of the uterine closure technique.

RESULTS

Of the 225 final participants, 109 received the single-layer closure technique, whereas 116 received the double-layer technique. The niche rates were 37% (n = 40) for the single-layer group and 45.7% (n = 53) for the double-layer group (P = .22, relative risk 1.4, 95% CI = 0.8-4.4).

CONCLUSIONS

The single- and double-layer closure techniques did not produce different impacts on uterine scar niche development.

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

OBJECTIVE

To evaluate whether double-layer uterine closure after a first caesarean section (CS) is superior compared with single-layer uterine closure in terms of postmenstrual spotting and niche development in the uterine caesarean scar.

DESIGN

Multicentre, double-blind, randomised controlled superiority trial.

SETTING

Thirty-two hospitals in the Netherlands.

POPULATION

A total of 2292 women aged ≥18 years undergoing a first CS were randomly assigned to each procedure (1:1): 1144 women were assigned to single-layer uterine closure and 1148 women were assigned to double-layer uterine closure.

METHODS

Single-layer unlocked closure and double-layer unlocked closure, with the second layer imbricating the first.

MAIN OUTCOME MEASURES

Number of days with postmenstrual spotting during one menstrual cycle 9 months after CS.

SECONDARY OUTCOMES

perioperative and menstrual characteristics; transvaginal ultrasound measurements.

RESULTS

A total of 774 (67.7%) women from the single-layer group and 770 (67.1%) women from the double-layer group were evaluable for the primary outcome, as a result of drop-out and amenorrhoea. The mean number of postmenstrual spotting days was 1.33 (bootstrapped 95% CI 1.12-1.54) after single-layer closure and 1.26 (bootstrapped 95% CI 1.07-1.45) after double-layer closure (adjusted mean difference -0.07, 95% CI -0.37 to 0.22, P = 0.810). The operative time was 3.9 minutes longer (95% CI 3.0-4.9 minutes, P < 0.001) and niche prevalence was 4.7% higher (95% CI 0.7-8.7%, P = 0.022) after double-layer closure.

CONCLUSIONS

The superiority of double-layer closure compared with single-layer closure in terms of postmenstrual spotting after a first CS was not shown. Long-term obstetric follow-up of our trial is needed to assess whether uterine caesarean closure guidelines should be adapted.

TWEETABLE ABSTRACT

Double-layer uterine closure is not superior for postmenstrual spotting after a first caesarean; single-layer closure performs slightly better on other outcomes.

Cesarean scar defects: management of an iatrogenic pathology whose prevalence has dramatically increased

Around 20% of pregnant women undergo cesarean section (CS), and in most regions of the world CS rates continue to grow. There is still no clear definition of what is considered a normal physiologic aspect of a CS scar and what is abnormal. Cesarean scar defects (CSDs) should be suspected in women presenting with spotting, dysmenorrhea, pelvic pain, or infertility and a history of CS. CSDs can be visualized with the use of hysterosalpingography, transvaginal sonography, saline infusion sonohysterography, hysteroscopy, and magnetic resonance imaging. It is reasonable to consider hormone therapy for CSDs as a symptomatic treatment in women who no longer wish to conceive and have no contraindications. In case of failure of or contraindications to medical treatment, surgery should be contemplated according to the severity of symptoms, including infertility, the desire or otherwise to preserve the uterus, the size of the CSD, and residual myometrium thickness (RMT) measurement. Hysteroscopy is considered to be more of a resection than a repair, so women who desire pregnancy should be excluded from this technique if the RMT is <3 mm, in which case repair is essential and can be achieved by only laparoscopic or vaginal approach. Women with CSDs need to be given complete information, including available literature, before any treatment decision is made. Because prevention is better than cure, risk factors should be identified early to ensure appropriate management.

Cesarean scar thickness in non-pregnant women as a risk factor for uterine rupture

Introduction: Whether there is an association between residual myometrial thickness (RMT) after cesarean section (CS) and the risk of uterine rupture (UR) or uterine scar dehiscence at the subsequent delivery has been sparsely investigated.Materials and methods: Our cohort included 149 women with a first CS in whom we measured RMT by transvaginal ultrasonography 6-15 months after their delivery. We did a follow-up study on delivery outcomes in the women's subsequent births. The exposure was scar measurements in the non-pregnant uterus, and the primary outcome was a diagnosis of UR or dehiscence. We calculated likelihood ratios (LRs) with 95% confidence intervals of having UR or dehiscence with a thin RMT (<3 mm).Results: Among the 149 women, 39 had a repeat CS (14 scheduled and 25 unscheduled procedures), and within these, we found one woman with UR and five women with uterine dehiscence. The proportion of women with a thin RMT was significantly higher among cases (4/6) than in controls (4/33); the LR was 5.5 (95% CI 1.9-16.2).Conclusions: The results suggest a significant association between a thin RMT as measured by transvaginal ultrasonography in the non-pregnant uterus after a first scheduled CS and the risk of UR or dehiscence at a subsequent delivery.

Endometrium-free uterine closure technique and abnormal placental implantation in subsequent pregnancies

BACKGROUND

Abnormal placentation can result in massive hemorrhage, which is the leading cause of severe maternal morbidities and mortality in its management. Over the past 50 years, the incidence of placenta previa (PP), abnormal implantation of the placenta, and cesarean scar pregnancy have continued to rise. This coincides with the well-documented parallel rise in the rate of cesarean deliveries, the performance of multiple repeat cesarean deliveries and the adoption of newer uterine closure techniques. However, no studies have examined the role of uterine closure techniques in abnormal placentation in women with a history of a prior cesarean delivery.

OBJECTIVE

To assess the practicality of one specific uterine closure technique at cesarean delivery and to evaluate the relationship between previous cesarean delivery and subsequent development of abnormal implantation of the placenta, as well as neonatal and other perioperative outcomes after receiving an endometrium-free uterine closure technique.

METHODS

This retrospective observational study considered cesarean deliveries (n = 727) and subsequent vaginal births after cesarean delivery (n = 109) among total deliveries (n = 4496) performed in private practice at NYU Langone Health from 1985 to 2015. All cesarean deliveries were performed using the endometrium-free uterine closure technique. The primary outcome was the incidence of abnormal implantation of the placenta in subsequent pregnancies. The secondary outcomes were neonatal and maternal complications, specifically postoperative hemoglobin and hematocrit concentration losses. The association between independent variables and outcomes were evaluated using mixed-effect regression models.

RESULTS

In contrast to published data, independent of the number of repeat cesarean deliveries, the presence of 26 (3.1%) PPs and of 366 (43.8%) anterior placentas, there were no patients with abnormal implantation of the placenta in a cesarean scar, neither prenatally nor at delivery. Maternal hemorrhage, postoperative and neonatal complications did not reach clinical significance. The statistical analysis revealed that, when compared with women who had fewer repeat cesarean deliveries using endometrium-free uterine closure technique, those with the most had a lesser risk of forming PP and less blood loss, as measured by both hematocrit and hemoglobin evaluation.

CONCLUSION

In this retrospective cohort study, the exclusion of the endometrium during the endometrium-free uterine closure technique was associated with fewer placental abnormalities in subsequent pregnancies and reduced life-threatening maternal morbidity for future cesarean deliveries.

Ultrasound cesarean scar assessment one year postpartum in relation to one- or two-layer uterine suture closure

INTRODUCTION

This study compared healing of the scars after cesarean section during the first postpartum year using a single- or double-layer suturing technique. Scarring was assessed by a transvaginal ultrasound. We explored the appearance and localization of uterine scars with regard to the obstetric history. Our aim was to compare the position of the scar or defect, if present, its dimensions, and any residual myometrium with respect to the suturing technique during the cesarean section.

MATERIAL AND METHODS

Women with uncomplicated singleton pregnancies indicated for elective or acute cesarean section were randomly allocated to the uterine closure technique group. During the first postpartum year, their lower uterine segment was examined with a transvaginal ultrasound in three consecutive visits at 6 weeks, 6 months and 12 months.

RESULTS

324 women attended the 12-month visit; of these, 149 underwent single-layer closure of the uterine incision and 175 double-layer technique. A higher proportion of the defects is seen in the single-layer closure technique of suturing. Defects in the single-layer group were wider (0.002) and the residual myometrial thickness in the single-layer group were thinner (0.019). Women who underwent cesarean section at the stage of full cervical dilation had scars that were closer to the external cervical os (0.000). The position of the uterus varies greatly between controls (0.000). The combination of uterine position and scar defect presence changed significantly between controls (0.001), and was significantly dependent on the suturing method (0.003). Defects with or without contact with the uterine cavity changed statistically between controls (0.017). Both types of defects were more common in the single-layer closure technique group.

CONCLUSIONS

The findings of this study demonstrate that double-layer technique with the first continuous nonlocking suture followed by a second continuous nonlocking suture is associated with better suture healing and greater residual myometrial thickness. No difference was observed between single- and double-layer closure for the presence of maternal infectious morbidity, wound infection or blood transfusion.

An Optimal Uterine Closure Technique for Better Scar Healing and Avoiding Isthmocele in Cesarean Section: A Randomized Controlled Study

Objective: The aim of this study is to compare the effects of two different uterine closure techniques, used during cesarean section (CS) operations on isthmocele formation. Material and Methods: This prospective, randomized, controlled study was performed on 138 patients in a university hospital between the dates December 2016 and August 2017. Uterine closures were performed using the double-layer, far-far-near-near (FFNN) unlocked technique, in the study group (n = 70) and using a single-layer continuous locked (SLL) technique in the control group (n = 68). The presence of isthmocele, residual myometrial thickness (RMT), postmenstrual spotting, dysmenorrhea, chronic pelvic pain and uterus position were evaluated in postoperative sixth month. Results: Isthmocele formation was less frequent and RMT was greater in the study group when compared to the control group (p < 0.001 and p < 0.001, respectively). Duration of operation, amount of blood loss and additional hemostatic suture requirement were not significantly different between the two groups (p = 0.221, p = 0.520 and p = 0.930, respectively). Postmenstrual spotting was less common in FFNN group, while the rates of chronic pelvic pain and dysmenorrhea were not significantly different between the groups (p = 0.002, p = 0.205 and p = 0.490, respectively). Conclusion: The findings of the present study demonstrate that uterine closure using the FFNN technique is beneficial in terms of providing protection from isthmocele formation and ensuring sufficient RMT. This method has the potential to become the optimal uterine closure technique, but the findings of the present study should be supported by large-scale studies in the future.

Hysterotomy level at Cesarean section and occurrence of large scar defects: a randomized single-blind trial

OBJECTIVE

To study the association between the level of Cesarean hysterotomy and the presence of large uterine scar defects 6-9 months after delivery.

METHODS

This was a two-center, randomized, single-blind trial of a surgical procedure with masked assessment of the principal outcome under study. Women without a history of Cesarean section (CS) who underwent emergency CS at cervical dilatation ≥ 5 cm were randomized to high or low incision. Hysterotomy was performed 2 cm above and 2 cm below the plica vesicouterina in the high and low incision groups, respectively. Women were examined using saline contrast sonohysterography to assess the appearance of the hysterotomy scar 6-9 months after delivery. The main outcome was presence of a large scar defect, defined as the remaining myometrial thickness over the defect being ≤ 2.5 mm. Secondary outcomes were perinatal outcome, operative complications within 8 weeks after delivery and long-term outcome in a subsequent pregnancy.

RESULTS

Of 122 patients enrolled in the trial, 114 were assessed by ultrasound examination, of whom 55 were randomized to high and 59 to low CS incision. Large scar defects were seen in four (7%) women in the high-incision group and in 24 (41%) in the low-incision group (P < 0.001; odds ratio, 8.7 (95% CI, 2.8-27.4)). There were no differences in operative complications and perinatal outcomes between the two groups. The median follow-up time was 4 years and 7 months, during which 56 (49%) women had a subsequent pregnancy. No significant differences were observed in the rate of complications in subsequent pregnancy and delivery between women who had low and those who had high incision at the index CS.

CONCLUSION

Low Cesarean hysterotomy level in women in advanced labor is associated with higher incidence of large scar defects detected by transvaginal ultrasound examination 6-9 months after delivery. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

The prevalence and risk predictors of cesarean scar defect at 6 weeks postpartum in Shanghai, China: A prospective cohort study

INTRODUCTION

The aim of this study was to explore the prevalence and predictors of cesarean scar defect (CSD) at 6 weeks postpartum in Shanghai, China.

MATERIAL AND METHODS

Women scheduled to receive a cesarean section (CS) were recruited from a university hospital. Surgery-related factors, pregnancy complications, routine examinations, perioperative medications, and physical signs were collected and transvaginal ultrasonography was performed to assess the presence of a CSD at 6 weeks postpartum. Multivariate logistic regression was applied to identify the predictors for CSD.

RESULTS

A CSD was detected in 223 of 514 women (43.4%, 95% CI 39.1%-47.7%) by transvaginal ultrasonography. Of women with normal temperature (T < 37.5°C, CSD prevalence 33.9%, 95% CI 28.4%-39.5%), women with postpartum fever (T ≥ 38°C, CSD 44.1%, 95% CI 31.0%-57.1%), and women who were subfebrile in the postpartum (37.5 ≤ T ≤ 38.0°C, CSD 58.3%, 95% CI 50.9%-65.7%), the latter two had significantly increased risk for CSD (adjusted odds ratio [aOR] 2.7, 95% CI 1.3-5.2 and aOR 3.3, 95% CI 2.1-5.3, respectively). In comparison to single-dose antibiotic administration (CSD 49.0%, 95% CI 43.8%-54.3%), multi-dose antibiotic administration (CSD 31.1%, 95% CI 23.8%-38.3%) had a protective effect (aOR 0.4, 95% CI 0.3-0.7). Postpartum fever, intrapartum infection, emergency CS, and cervical dilation ≥ 3 cm were found to be the main predictors of multi-dose antibiotics management. Low platelet count postpartum (defined as ≤ 150 × 10⁹ /L) and high fibrinogen pre-CS (defined as ≥ 4.5 g/L) increased CSD risk (aOR 2.0, 95% CI 1.1-3.6 and 1.7, 95% CI 1.1-2.5, respectively).

CONCLUSIONS

The prevalence of CSD in the Chinese population is high enough to be a concern. Perioperative infection and hypercoagulability should be considered CSD predictors, and multi-dose antibiotics have a protective effect.

Does ultrasound-guided intervention during repeat cesarean sections improve uterine scar architecture and reduce the number of scars? A prospective controlled clinical intervention trial

Purpose To evaluate whether intraoperative ultrasound-guided detection and resection of the uterine scar during repeat/second cesarean can reduce the number of scars and improve uterine scar architecture. Materials and methods A prospective controlled clinical intervention trial was performed with the following groups: control group 1 (CS1-G): first cesarean; control group 2 (CS2-G): second cesarean utilizing the usual procedure and intervention group (Int-G): repeat/second cesarean with intervention. Transvaginal ultrasound scans were performed 6-9 months after each cesarean. Both primary (double scarring rate) and secondary outcomes [deficiency ratio=d/(b+d)] were analyzed. The deficiency ratio describes the thinning of the remaining myometrium (d=residual myometrial thickness) over the "apparent" defect (b=scar depth). Results In total, 124 of the 156 recruited women were examined, eight were excluded from analysis. The double scarring rate decreased from 42.9% (12/28) in CS2-G to 7.1% (2/28) in the Int-G [difference: 35.8%; 95% confidence interval (CI) (13.2, 54.5); P=0.002]. Two-way analysis of variance (ANOVA) revealed a significant difference between CS2-G and the Int-G in the deficiency ratio adjusted for elective/primary cesareans, with thicker remaining myometrium over the scar defect in the Int-G [difference: -0.24; 95% CI (-0.34, -0.15); P<0.001]. Conclusion Ultrasound-guided resection of the uterine scar area during repeat cesareans reduces the scarring rate and improves thickness of the remaining myometrium as detected by ultrasonography 6-9 months postoperatively.

Myomectomy scar ectopic pregnancy following a cryopreserved embryo transfer

CASE

A 40 year old woman with a history of a myomectomy visited the Department of Obstetrics and Gynecology, Niigata University Medical and Dental Hospital, Niigata, Japan, following 2 years of infertility. Magnetic resonance imaging detected an abnormal endometrial-like pseudo-cavity. A hysterosalpingography also revealed an abnormal accumulation of contrast medium at the myometrial scar site. A transvaginal ultrasound showed a thin myometrium at the lower uterine body. The patient conceived via in vitro fertilization under a luteal phase down-regulation protocol (long protocol) for controlled ovarian stimulation, followed by a cryopreserved embryo transfer during her natural ovulation cycle. After the embryo transfer, the gestational sac was located at the subserosal site of the myomectomy scar.

OUTCOME

An emergent laparoscopic operation was performed and the embryo was removed successfully via laparoscopy under transvaginal ultrasonography.

CONCLUSION

A subserosal uterine pregnancy is a rare form of intramural pregnancy, which is a rare subtype of an ectopic pregnancy, which could occur at the myomectomy site, especially after an embryo transfer. It is believed that this rare ectopic pregnancy resulted from embryo implantation under the serosa through a micro-sinus tract that was a site of suture failure of the myomectomy scar and was partially affected by the embryo transfer. Clinicians should consider the possibility of an ectopic pregnancy after uterine surgery, including a myomectomy.

Uterine caesarean closure techniques affect ultrasound findings and maternal outcomes: a systematic review and meta-analysis

BACKGROUND

Caesarean section (CS) rates are rising globally. Long-term adverse outcomes after CS might be reduced when the optimal uterine closure technique becomes evident.

OBJECTIVE

To determine the effect of uterine closure techniques after CS on maternal and ultrasound outcomes.

SEARCH STRATEGY

Literature search in electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or prospective cohort studies that evaluated uterine closure techniques and reported on ultrasound findings, perioperative or long-term outcomes.

DATA COLLECTION AND ANALYSIS

Twenty studies (15 053 women) were included in our meta-analyses for various outcomes. We calculated pooled risk ratios (RR) and weighted mean differences (WMD) with 95% CI through random-effect analysis.

MAIN RESULTS

Residual myometrium thickness (RMT), reported in eight studies (508 women), decreased by 1.26 mm after single- compared with double-layer closure (95% CI -1.93 to -0.58), particularly when locked sutures were used. Healing ratio [RMT/adjacent myometrium thickness (AMT)] decreased after single-layer closure (WMD -7.74%, 95% CI -13.31 to -2.17), particularly in the case of locked sutures. Niche prevalence increased (RR 1.71, 95% CI 1.11-2.62) when the decidua was excluded. Dysmenorrhea occurred more often in the single-layer group (RR 1.23, 95% CI 1.01-1.48), whereas incidence of uterine rupture was similar (RR 1.91, 95% CI 0.63-5.74).

CONCLUSION

Double-layer unlocked sutures are preferable to single-layer locked sutures regarding RMT, healing ratio and dysmenorrhoea. Excluding the decidua seems to result in higher niche prevalence. As thin residual myometrium or niches may serve as intermediates for gynaecological and reproductive outcomes, future studies should focus on these outcomes. TWEETABLE ABSTRACT: #Uterineclosuretechniques after #caesarean affect #longtermoutcomes.

Operative technique at caesarean delivery and risk of complete uterine rupture in a subsequent trial of labour at term. A registry case-control study

Objective

To estimate the relation of single-layer closure at previous caesarean delivery, and other pre-labour and intra-partum risk factors for complete uterine rupture in trial of vaginal birth after a caesarean (TOLAC) at term.

Study design

Population-based case-control study. We identified all women (n = 39 742) recorded in the Danish Medical Birth Registry (DMBR) during a 12-year period (1997–2008) with a singleton pregnancy at term and TOLAC. Among these, all women with a complete uterine rupture were identified (cases). Information from the registry was validated against medical records. Controls were selected in the DMBR as the following two births with TOLAC at term and no uterine rupture. Detailed information from cases and controls was collected from manual review of medical records. Main outcome measure was complete uterine rupture during TOLAC at term.

Results

Upon validation, 175 cases and 272 controls met the above criteria. After adjustment for possible confounding factors there was no association between single layer closure and uterine rupture (aOR 1.38, CI: 0.88–2.17). Significant risk factors were: Induction with an unfavourable cervix (aOR 2.10 CI: 1.19–3.71), epidural (aOR 2.17 CI 1.31–3.57), augmentation by oxytocin for more than one hour (aOR 2.03 CI: 1.20–3.44), and birth weight ≥ 4000g (aOR 2.65 CI 1.05–6.64). Previous vaginal delivery (aOR 0.41 CI: 0.25–0.68) and inter-delivery interval of more than 24 months (aOR 0.38 CI: 0.18–0.78) reduced the risk of uterine rupture.

Conclusion

Single-layer uterine closure did not remain significantly associated to uterine rupture during TOLAC at term after adjustment for confounding factors. Induction of labour with an unfavourable cervix, birth weight ≥ 4000g and indicators of prolonged labour were all major risk factors for uterine rupture.

Risk of Cesarean scar defect following single- vs double-layer uterine closure: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

There is a growing body of evidence that suggests that the surgical technique for uterine closure following Cesarean delivery influences the healing of the Cesarean scar, but there is still no consensus on the optimal technique. The aim of this systematic review and meta-analysis was to compare the effect of single- vs double-layer uterine closure on the risk of uterine scar defect.

METHODS

MEDLINE, Scopus, ClinicalTrials.gov, PROSPERO, EMBASE and the Cochrane Central Register of Controlled Trials were searched from inception of each database until May 2016. All randomized controlled trials (RCTs) evaluating the effect of single- vs double-layer uterine closure following low transverse Cesarean section on the risk of uterine scar defect were included. The primary outcome was the incidence of uterine scar defects detected on ultrasound. Secondary outcomes were residual myometrial thickness evaluated by ultrasound and the incidence of uterine dehiscence and/or rupture in subsequent pregnancy. Summary measures were reported as relative risk (RR) or mean difference (MD), with 95% CIs. Quality of the evidence was assessed using the GRADE approach.

RESULTS

Nine RCTs (3969 participants) were included in the meta-analysis. The overall risk of bias of the included trials was low. Statistical heterogeneity within the studies was low, with no inconsistency in the primary and secondary outcomes. Women who received single-layer uterine closure had a similar incidence of uterine scar defects as did women who received double-layer closure (25% vs 43%; RR, 0.77 (95% CI, 0.36-1.64); five trials; 350 participants; low quality of evidence). Compared with double-layer uterine closure, women who received single-layer closure had a significantly thinner residual myometrium on ultrasound (MD, -2.19 mm (95% CI, -2.80 to -1.57 mm); four trials; 374 participants; low quality of evidence). No difference was found in the incidence of uterine dehiscence (0.4% vs 0.2%; RR, 1.34 (95% CI, 0.24-4.82); three trials; 3421 participants; low quality of evidence) or uterine rupture (0.1% vs 0.1%; RR, 0.52 (95% CI, 0.05-5.53); one trial; 3234 participants; low quality of evidence) in a subsequent pregnancy.

CONCLUSIONS

Single- and double-layer closure of the uterine incision following Cesarean delivery are associated with a similar incidence of Cesarean scar defects, as well as uterine dehiscence and rupture in a subsequent pregnancy. However, the quality level of summary estimates, as assessed by GRADE, was low, indicating that the true effect may be, or is even likely to be, substantially different from the estimate of the effect. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Single versus double-layer uterine closure at cesarean: impact on lower uterine segment thickness at next pregnancy

BACKGROUND

Uterine rupture is a potential life-threatening complication during a trial of labor after cesarean delivery. Single-layer closure of the uterus at cesarean delivery has been associated with an increased risk of uterine rupture compared with double-layer closure. Lower uterine segment thickness measurement by ultrasound has been used to evaluate the quality of the uterine scar after cesarean delivery and is associated with the risk of uterine rupture.

OBJECTIVE

To estimate the impact of previous uterine closure on lower uterine segment thickness.

STUDY DESIGN

Women with a previous single low-transverse cesarean delivery were recruited at 34-38 weeks' gestation. Transabdominal and transvaginal ultrasound evaluation of the lower uterine segment thickness was performed by a sonographer blinded to clinical data. Previous operative reports were reviewed to obtain the type of previous uterine closure. Third-trimester lower uterine segment thickness at the next pregnancy was compared according to the number of layers sutured and according to the type of thread for uterine closure, using weighted mean differences and multivariate logistic regression analyses.

RESULTS

Of 1613 women recruited, with operative reports available, 495 (31%) had a single-layer and 1118 (69%) had a double-layer closure. The mean third-trimester lower uterine segment thickness was 3.3 ± 1.3 mm and the proportion with lower uterine segment thickness <2.0 mm was 10.5%. Double-layer closure of the uterus was associated with a thicker lower uterine segment than single-layer closure (weighted mean difference: 0.11 mm; 95% confidence interval [CI], 0.02 to 0.21 mm). In multivariate logistic regression analyses, a double-layer closure also was associated with a reduced risk of lower uterine segment thickness <2.0 mm (odd ratio [OR], 0.68; 95% CI, 0.51 to 0.90). Compared with synthetic thread, the use of catgut for uterine closure had no significant impact on third-trimester lower uterine segment thickness (WMD: -0.10 mm; 95% CI, -0.22 to 0.02 mm) or on the risk of lower uterine segment thickness <2.0 mm (OR, 0.95; 95% CI, 0.67 to 1.33). Finally, double-layer closure was associated with a reduced risk of uterine scar defect (RR, 0.32; 95% CI, 0.17 to 0.61) at birth.

CONCLUSION

Compared with single-layer closure, a double-layer closure of the uterus at previous cesarean delivery is associated with a thicker third-trimester lower uterine segment and a reduced risk of lower uterine segment thickness <2.0 mm in the next pregnancy. The type of thread for uterine closure has no significant impact on lower uterine segment thickness.

Comparison of the primary cesarean hysterotomy scars after single- and double-layer interrupted closure

INTRODUCTION

It is unclear whether hysterotomy closure techniques can affect niche development. Therefore, this study aimed to analyze the effect of single-layer and double-layer interrupted closures of hysterotomy incisions during primary cesarean section on the formation of uterine niches.

MATERIAL AND METHODS

A prospective cohort study of women undergoing primary cesarean section was performed between June 2011 and July 2014. Saline contrast sonohysterography was used to measure the niche depth and residual myometrium. The ratio of the niche depth to the sum of the niche depth and residual myometrium thickness (niche ratio) was calculated.

RESULTS

Niches were identified in 14/58 (24.1%) women with single-layer sutures and 55/209 (26.3%) women with double-layer sutures (p = 0.74). Single-layer closure was associated with more than a five-fold increase in the odds of a niche ratio ≥0.4 (odds ratio 5.59; 95% CI 1.71-18.28).

CONCLUSION

Single-layer closure may be associated with an increased risk of larger niches (niche ratio ≥0.4), although it may not increase the overall frequency of niche formation.