The effect of laparoscopic resection of large niches in the uterine caesarean scar on symptoms, ultrasound findings and quality of life: a prospective cohort study

Risk factors and influence of surgical technique on the risk of caesarean scar defect formation: A systematic review of the literature

OBJECTIVE

To determine the factors associated with an increased risk of cesarean scar defect formation.

METHODS

A systematic literature search was performed up to July 2022 in PubMed databases following the PRISMA recommendations. All available English-language clinical studies presenting one or more factors that may affect the risk of cesarean scar defect were included.

RESULTS

39 studies meeting the selection criteria were identified. An association was found between the number of previous cesarean sections and a significant increase in the risk of cesarean scar defect formation. Regarding patient age, gestational age at cesarean section, birth weight and emergency context did not appear to influence the risk of cesarean scar defect. However, cesarean sections performed during labor advanced stages of labor, may increase the risk. The data remain too limited to conclude on the impact of BMI, flexion uterine, and pregnancy pathologies (gestational diabetes, preeclampsia, premature rupture of membranes), the use of oxytocic, or infectious and hemorrhagic complications. Regarding the surgical technique, the literature suggested that a lower hysterotomy is associated with an increased risk of scar defect. However, the single- or double-layer suture technique did not provide a change in risk, and the data were too limited to conclude on the impact of the type of thread or suture used.

CONCLUSION

The present systematic review of the literature suggests that several factors may increase the risk of developing a cesarean scar defect, such as the number of previous cesarean sections, a cesarean section performed during advanced labor, and a lower hysterotomy. However, the current state of the literature does not allow definitive conclusions to be drawn on most other factors.

Isthmocele diagnosis: The optimal timing for detection

We describe the changes in size of the uterine niche during the proliferative and secretory phases, highlighting the need to standardize the best time of measurement.

From Diagnosis to Delivery: Navigating Pregnancy With an Isthmocele

Isthmocele is a myometrial defect in the uterine isthmus, often resulting from previous caesarean sections. With rising cesarean rates globally, including a significant increase in India, the prevalence of isthmocele has become a noteworthy clinical concern. Isthmocele can lead to symptoms such as abnormal uterine bleeding, dysmenorrhea, and secondary infertility, often detected through transvaginal ultrasound or MRI. Additionally, it can lead to caesarean scar pregnancy, a serious complication. The condition necessitates treatment, particularly in symptomatic cases or those planning future pregnancies. Early diagnosis and appropriate management are crucial for preventing complications and ensuring positive pregnancy outcomes. Here, we report a case that underscores the potential for successful pregnancy outcomes despite the presence of isthmocele, highlighting the need for tailored management strategies in such high-risk cases.

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.

Hysteroscopic Management of Symptomatic Cesarean Scar Diverticulum in Patients Undergoing Frozen-Thawed Embryo Transfer: Impact on Clinical Pregnancy Rates and Pregnancy Complications

This retrospective cohort study aimed to compare the clinical outcomes of patients with cesarean scar defect (CSD) undergoing frozen embryo transfer (FET) with or without hysteroscopic repair surgery. The study included 82 patients, with 48 patients in surgical group A (undergoing CSD repair) and 34 patients in surgical group B (undergoing hysteroscopic treatment for other uterine lesions). The results showed that patients in group A had a larger CSD volume and a different shape compared to group B. However, there was no significant difference in clinical pregnancy rates between the two groups. Additionally, there were no differences in miscarriage, live birth, or preterm birth rates, and no complications such as scar pregnancy or placental abnormalities were observed in either group. These findings suggest that hysteroscopic treatment of CSD in symptomatic patients undergoing FET does not increase the risk of pregnancy complications and can lead to comparable clinical pregnancy rates with asymptomatic patients. Further studies with larger sample sizes are needed to confirm these results and evaluate long-term reproductive outcomes following CSD repair.

Effectiveness of an articulating laparoscopic needle holder for cesarean scar defect repair

AIM

To evaluate the efficacy of an articulating laparoscopic needle holder in laparoscopic surgery for cesarean scar defect.

METHODS

We performed a retrospective case-control study at the Shiga University of Medical Science. Patients who underwent laparoscopic uterine scar repair were divided into an articulating laparoscopic needle holder (ArtiSential®) group and a rigid needle holder (conventional) group to compare the suture and total operative times. Uterine myometrial suturing involves a double-layer interrupted suture, including a modified Gambee suture for the first layer. We measured the residual myometrial thickness using magnetic resonance imaging preoperatively and at 3 months postoperatively.

RESULTS

Both groups comprised 10 patients each. The time per stitch for the first and second layers was significantly shorter in the ArtiSential group than in the conventional group (median 208 s vs. 403 s, p < 0.0001 and median 17 s vs. 29 s; p < 0.0001, respectively). The total operating time was significantly shorter in the ArtiSential group (mean 188 min vs. 240 min, p = 0.0015). The postoperative residual myometrial thickness (mean 9.1 mm in the ArtiSential group and 9.6 mm in the conventional group) was significantly higher than the preoperative residual myometrial thickness (mean 1.6 mm in the ArtiSential group and 1.6 mm in the conventional group) (p < 0.0001 in both groups).

CONCLUSIONS

An articulating needle holder is useful in laparoscopic surgery for cesarean scar defect, especially when a modified Gambee suture is required.

Reproductive outcomes after in vitro fertilization in women with cesarean section scar diverticulum: A retrospective study

PURPOSE

Some studies have suggested that cesarean section diverticulum may affect the pregnancy outcomes of assisted reproductive technology through a variety of mechanisms. This study aims to explore whether previous cesarean section and uterine scar diverticulum affect pregnancy outcomes after in vitro fertilization.

METHODS

This retrospective study included 954 infertile women with only one previous delivery who had in vitro fertilization treatment and underwent fresh embryo transplantation for the first time at our center between 2015 and 2019. We first divided the women into two groups by previous vaginal delivery (n = 557) or cesarean section delivery (n = 397), and the latter group included 88 women with cesarean diverticulum and 309 women without cesarean diverticulum. Baseline characteristics were compared and analyzed, and logistic regression analyses were performed to explore the different pregnancy outcomes among the above groups.

RESULTS

Although the live birth rate, clinical pregnancy rate, and mean embryo implantation rate after in vitro fertilization were significantly reduced in patients with previous cesarean section (live birth rate: 26.45% vs. 43.99%, adjusted OR: 0.602, CI: 0.447-0.810; clinical pregnancy rate: 35.26% vs. 49.91%, adjusted OR: 0.724, CI: 0.544-0.962; mean embryo implantation rate: 0.227 ± 0.378 vs. 0.243 ± 0.397, adjusted OR: 0.860, CI: 0.514-1.439), there were no significant differences in pregnancy outcomes between the women with cesarean diverticulum and without cesarean diverticulum (p > 0.05) or between the two groups at different ages. The live birth and clinical pregnancy rates in the women with residual muscle thickness ≤2.2 mm or prolonged menstruation were reduced, but the difference was not statistically significant (p > 0.05).

CONCLUSION

This study showed reduced pregnancy and live birth rates after in vitro fertilization in patients with previous cesarean section, while uterine scarring did not adversely affect pregnancy and delivery outcomes after in vitro fertiliazation.

Efficacy, Safety and Outcomes of the Laparoscopic Management of Cesarean Scar Ectopic Pregnancy as a Single Therapeutic Approach: A Case Series

A standardized consensus for the management of cesarean scar pregnancy (CSP) is lacking. The study objective is to evaluate the efficacy, safety and outcomes of the laparoscopic management of CSP as a single therapeutic surgical approach without being preceded by vascular pretreatment or vasoconstrictors injection. This is a retrospective bi-centric study, a case series. Eight patients with a future desire to conceive underwent the laparoscopic treatment of unruptured CSPs. Surgery consisted of "en bloc" excision of the deficient uterine scar with the adherent tissue of conception, followed by immediate uterine repair. The data collected for each patient was age, gestity, parity, number of previous c-sections, pre-pregnancy isthmocele-related symptoms, gestational age, fetal cardiac activity, initial β-human chorionic gonadotropin levels, intra-operative blood loss, blood transfusion, operative time and the postoperative complications, evaluated according to Clavien-Dindo classification. The CSP was successfully removed in all patients by laparoscopy. The surgical outcomes were favorable. All patients with histories of isthmocele-related symptoms reported postoperative resolution of symptoms. The median residual myometrium thickness increased significantly from 1.2 mm pre-operatively to 8 mm 3 to 6 months after surgery. The laparoscopic management seems to be an appropriate treatment of CSP when performed by skilled laparoscopic surgeons. It can be safely proposed as a single surgical therapeutic approach. Larger series and further prospective studies are needed to confirm this observation and to affirm the long-term gynecological and obstetrical outcomes of this management.

Value and influencing factors of preoperative MRI evaluation for previous cesarean scar defect associated abnormal uterine bleeding in patients undergoing laparoscopic surgery

OBJECTIVES

As the cesarean section rate increases year by year, the treatment of previous cesarean scar defects (PCSD) poses a significant challenge. This study aims to evaluate the clinical value of preoperative magnetic resonance imaging (MRI) technology and analyze relevant influencing factors for patients with abnormal uterine bleeding (AUB) associated with cesarean scar defects who underwent laparoscopic surgery.

METHODS

A retrospective cohort analysis was performed on women who underwent laparoscopic surgery for PCSD-related AUB at the Department of Gynecology, the Third Xiangya Hospital of Central South University from 2018 to 2022. A total of 57 patients who underwent laparoscopic surgery for the treatment of AUB associated with PCSD were divided into 2 groups based on their postoperative clinical cure status: The clinically-cured group (n=28, 49.1%) and the non-clinically-cured group (n=29, 50.9%). After a postoperative follow-up period of 3 months for all participants, logistic regression analysis was conducted to explore the correlation between the clinical cure rate of AUB associated with cesarean scar defects treated by laparoscopic surgery and various factors. These factors included patient age, clinical symptoms, obstetric history, history of cesarean section, basic clinical information, preoperative MRI parameters, and postoperative menstrual conditions.

RESULTS

There were no significant differences in many aspects, including the patient's age at the time of previous cesarean section, number of pregnancy, time since the previous cesarean section, the uterus position assessed by preoperative T2 signal MRI, defect length, defect width, residual muscle layer thickness, adjacent uterine muscle layer thickness, and distance from the defect to the external cervical os between the 2 groups (all P>0.05). However, the time of onset of AUB symptoms (P=0.036, OR=1.019, 95% CI 1.002 to 1.038) and the depth of the defect on the preoperative MRI (P=0.010, OR=5.793, 95% CI 1.635 to 25.210) were identified as risk factors affecting the clinical cure rate.

CONCLUSIONS

The time of onset of AUB symptoms and the depth of the defect on preoperative MRI are risk factors that influence the clinical cure rate of laparoscopic surgery for the treatment of AUB associated with PCSD, which could be helpful for evaluating the prognosis of disease.

Reproductive outcomes after laparoscopic resection of symptomatic niches in uterine cesarean scars: Long-term follow-up on the prospective LAPNICHE study

INTRODUCTION

After incomplete healing of the uterine cesarean section scar, a niche can be observed; 24% of the women develop large niches with a residual myometrial thickness <3 mm. In these cases a laparoscopic resection is possible. The effect of this new treatment on fertility outcome is not known yet. This paper describes reproductive outcomes 2 years after a laparoscopic niche resection and compares women with or without secondary infertility at baseline.

MATERIAL AND METHODS

A prospective cohort study was performed, with consecutive inclusion of women between 2011 and 2019. Women with a niche in the uterine cesarean scar, with a residual myometrial thickness of <3 mm and with a desire to become pregnant, were scheduled to undergo a laparoscopic niche resection because of one or more of the following problems (1) postmenstrual spotting; (2) midcycle intrauterine fluid accumulation diagnosed during the fertility workup or (3) difficulties with a previous embryo transfer and preferring a surgical therapy. The study is registered in the ISRCTN register (ref. no. ISRCTN02271575) on April 23, 2013.

RESULTS

There were 133 (62%) women included with a desire to become pregnant, 88 with secondary infertility. In all, 83 had an ongoing pregnancy at the 2-year follow-up. The ongoing pregnancy rate in patients with previous fertility problems was 60.2% compared with 66.7% in patients without infertility (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.32-1.7). The OR for live births was 0.57 (95% CI 0.02-1.2). Overall, 8.3% of the pregnancies resulted in miscarriages by the 2-year follow-up.

CONCLUSIONS

The reproductive outcomes in women with and without previous fertility problems undergoing resection of a large niche are very promising and quite comparable in both groups. These results suggest, but do not prove, a beneficial effect of this therapy for these indications. The results support the design of future randomized controlled trials to evaluate the effect of niche resection vs expectant management to assess its additional value in women with or without fertility problems who desire pregnancy.

Assessment of the clinical outcomes and complications of hysteroscopic and laparoscopic approaches in the treatment of symptomatic isthmocele: An observational study

OBJECTIVES

To investigate the outcomes of patients undergoing laparoscopic or hysteroscopic approaches for isthmoplasty.

METHODS

A total of 99 isthmocele patients with an average age of 38.45 ± 4.72 years were included in the 2 years of this retrospective cohort study. Forty-five underwent laparoscopic and 54 underwent hysteroscopic isthmocele excision and myometrial repair.

RESULTS

Pain scores were significantly higher in the hysteroscopy group before the procedure, but there were no significant pain score differences after the surgery. In 1 year of follow up, dysmenorrhea and dyspareunia were higher among hysteroscopy patients. Furthermore, hysteroscopy significantly improved postmenstrual spotting after surgery better than laparoscopy, but in the follow up, there was no significant difference between the two groups in this regard (mean rank for hysteroscopy vs. laparoscopy: 32.30 vs. 37.48, U = 418, P = 0.29).

CONCLUSION

In patients with a history of infertility, ectopic pregnancy, lower gravidity, lower parity, and a lower number of cesarean sections, laparoscopic isthmoplasty is preferred over the hysteroscopic approach. Both methods have similar effects on midcycle vaginal bleeding, duration of postmenstrual spotting, and pain. However, a higher rate of dyspareunia and dysmenorrhea could be associated with hysteroscopy.

Diagnosis and management of isthmocele (Cesarean scar defect): a SWOT analysis

The purpose of this State-of-the-Art Review was to provide a strategic analysis, in terms of strengths, weaknesses, opportunities and threats (SWOT analysis), of the current evidence regarding the management of uterine isthmocele (Cesarean scar defect). Strengths include the fact that isthmocele can be diagnosed on two-dimensional transvaginal ultrasound, and that surgical repair may restore natural fertility potential and prevent secondary infertility, as well as reduce the risk of miscarriage and other obstetric complications. However, there is a lack of high-quality evidence regarding the best diagnostic method and criteria, as well as the potential benefits of surgical repair with respect to fertility. There is a need for experienced surgeons skilled in the various isthmocele repair techniques. Isthmocele repair does not prevent the need for Cesarean delivery in subsequent pregnancies. There is increasing awareness regarding the accuracy of transvaginal ultrasound in diagnosing isthmocele. This may lead to surgical correction and prevention of obstetric and perinatal complications in subsequent pregnancies, including Cesarean scar pregnancy. Regarding threats, the existence of different surgical techniques means that there is a risk of selecting an inadequate approach if the type of isthmocele and the patient's characteristics are not considered. There is a risk of overtreatment when asymptomatic defects are repaired surgically. Finally, there is an absence of cost-effectiveness analyses to justify routine repair. Thus, while there are many data suggesting that isthmocele has an adverse effect on both natural fertility and the outcome of assisted reproduction techniques, high-quality evidence to support surgical isthmocele repair in all asymptomatic patients desiring future fertility are lacking. There is increasing agreement to recommend hysteroscopic repair of isthmocele as a first-line approach as long as the residual myometrial thickness is at least 2.5-3.0 mm. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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.

The definition, diagnosis, and symptoms of the uterine niche - A systematic review

Of all neonates, 21% are delivered by cesarean section (CS). A long-term maternal complication of an SC is a uterine niche. The aim of this review is to provide an overview of the current literature on imaging techniques and niche-related symptomatology. We performed systematic searches on imaging and niche symptoms. For both searches, 87 new studies were included. Niche evaluation by transvaginal sonography (TVS) or contrast sonohysterography (SHG) proved superior over hysteroscopy or magnetic resonance imaging. Studies that used SHG in a random population identified a niche prevalence of 42%-84%. Niche prevalence differed based on niche definition, symptomatology, and imaging technique. Most studies reported an association with gynecological symptoms, poor reproductive outcomes, obstetrical complications, and reduced quality of life. In conclusion, non-invasive TVS and SHG are the superior imaging modalities to diagnose a niche. Niches are prevalent and strongly associated with gynecological symptoms and poor reproductive outcomes.

Effectiveness of laparoscopic niche resection versus expectant management in patients with unexplained infertility and a large uterine caesarean scar defect (uterine niche): protocol for a randomised controlled trial (the LAPRES study)

INTRODUCTION

A uterine niche is a defect at the site of the uterine caesarean scar that is associated with gynaecological symptoms and infertility. Promising results are reported in cohort studies after a laparoscopic niche resection concerning reduction of gynaecological symptoms in relation to baseline and concerning pregnancy outcomes. However, randomised controlled trials to study the effect of a laparoscopic niche resection on reproductive outcomes in infertile women are lacking. This study will answer the question if laparoscopic niche resection in comparison to expectant management improves reproductive outcomes in infertile women with a large uterine niche.

METHODS AND ANALYSIS

The LAPRES study is a randomised, non-blinded, controlled trial, including 200 infertile women with a total follow-up of 2 years. Women with the presence of a large niche in the uterine caesarean scar and unexplained infertility of at least 1 year or failed IVF will be randomly allocated to a laparoscopic niche resection within 6 weeks or to expectant management for at least 9 months. A large niche is defined as a niche with a depth of >50% of the myometrial thickness and a residual myometrium of ≤3 mm on transvaginal ultrasound. Those receiving expectant management will be allowed to receive fertility therapies, including assisted reproductive techniques, if indicated. The primary outcome is time to ongoing pregnancy, defined as a viable intrauterine pregnancy at 12 weeks' gestation. Secondary outcome measures are time to conception leading to a live birth, other pregnancy outcomes, received fertility therapies after randomisation, menstruation characteristics, patient satisfaction, quality of life, additional interventions, and surgical and ultrasound outcomes (intervention group). Questionnaires will be filled out at baseline, 6, 12 and 24 months after randomisation. Ultrasound evaluation will be performed at baseline and at 3 months after surgery.

ETHICS AND DISSEMINATION

The study protocol was approved by the medical ethics committee of the Amsterdam University Medical Centre. (Ref. No. 2017.030). Participants will sign a written informed consent before participation. The results of this study will be submitted to a peer-reviewed journal for publication. TRIAL REGISTRATION NUMBER DUTCH TRIAL REGISTER REF NO NL6350 : http://www.trialregister.nl.

Impact of Adenomyosis and Endometriosis on Chronic Pelvic Pain after Niche Repair

Chronic pelvic pain (CPP) is one of the main isthmocele symptoms, together with abnormal uterine bleeding and secondary infertility. When patients undergo a laparoscopic niche repair surgery, it is important to determine if they present associated pathologies, such as adenomyosis and/or endometriosis, which are also a cause of CPP. A retrospective study was performed on 31 patients with CPP undergoing a laparoscopic niche repair. The pre-operative ultrasound was analyzed to determine the presence of adenomyosis. Endometriosis was histologically diagnosed. CPP outcome was evaluated at early (3-6 months) and late (12 months) post-operative follow ups. In our population of 31 women presenting CPP, only six of them (19.4%) did not have any associated pathology. In the group of 25 patients with associated pathology, 10 (40%) had no benefit from the reconstructive surgery in terms of CPP at early follow-up (3-6 months) and 8 (32%) in the post-operative period at 12 months. Patients with CPP who undergo niche repair should be carefully selected as CPP does not seem to be a good indication for uterine scar repair in patients with concomitant adenomyosis and endometriosis.

Uterine niche is associated with adverse in vitro fertilization and intracytoplasmic sperm injection outcomes: a retrospective cohort study

OBJECTIVE

To investigate the relationship between uterine niche and reproductive outcomes of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

DESIGN

A retrospective cohort study.

SETTING

A reproductive medicine center.

PATIENT(S)

A total of 2,449 women with cesarean section history who underwent 2,874 IVF/ICSI cycles between January 2015 and December 2019.

INTERVENTION(S)

A defect deeper than 2 mm visible under three-dimensional transvaginal sonography or hysteroscopy was defined as uterine niche. The IVF/ICSI outcomes of the first embryo transfer were obtained by telephone interview 1 year after embryo transfer regardless of fresh embryos or frozen-thawed embryos. Generalized estimating equations, logistic regression analyses, and propensity score matching were applied to clarify the relationship between uterine niche and IVF/ICSI outcomes.

MAIN OUTCOME MEASURE(S)

Primary outcome was live birth rate. Secondary outcomes were positive human chorionic gonadotropin test results, clinical pregnancy rate, implantation rate, miscarriage rate, and ectopic pregnancy rate.

RESULTS

After excluding 48 cycles for uterine malformation; 18 cycles for chromosome abnormality; 281 cycles for no available embryo or no embryo transfer; 5 cycles for oocyte donation; and 7 cycles for loss of follow-up, we finally included 2,231 women with 2,515 cycles in our study. Compared with women without niche, women with niche had reduced live birth rate (18.99% vs. 31.51%, : 0.51, 95% CI: 0.34-0.77), positive human chorionic gonadotropin test rate (34.08% vs. 46.40%, adjusted odds ratio [aOR]: 0.61, 95% confidence interval [CI]: 0.43-0.87), clinical pregnancy rate (29.05% vs. 42.25%, aOR: 0.57, 95% CI: 0.39-0.82) and implantation rate (25.87% vs. 36.95%, aOR: 0.53, 95% CI: 0.38-0.76). In all the sensitivity analyses, the niche group had a 7.28% to 18.22% increase in miscarriage rate even not all of them were statistically significant.

CONCLUSION(S)

Uterine niche may have a detrimental effect on subsequent fertility of women with cesarean section history undergoing IVF/ICSI treatment. Practitioners should be noted that women with uterine niches may be associated with adverse IVF/ICSI outcomes.

Construction and application of a prediction model for the delivery outcome of women with scarred uterus based on ultrasonic parameters

OBJECTIVE

To explore the application value of the prediction model for delivery outcome of women with scarred uterus based on ultrasonic parameters.

METHODS

In this retrospective study, a total of 100 pregnant women with scarred uterus who delivered in Cangzhou Hospital of Integrated Traditional Chinese Medicine and Western Medicine were selected as the research subjects. Adverse pregnancy outcomes included premature delivery, low birth weight, neonatal asphyxia, postpartum hemorrhage, and uterine rupture. In line with delivery outcome, the pregnant women were segmented into good outcome group (n = 78) and poor outcome group (n = 22). We collected and compared the clinical data and the ultrasonic parameters of pregnant women of the two groups. Multivariate logistic regression analysis was conducted to explore the risk factors affecting the delivery outcome of women with scarred uterus and to establish a prediction model.

RESULTS

Multivariate logistic regression analysis showed that low hemoglobin (Hb) before delivery, high grade of uterine scar, low muscle thickness of lower uterine segment, and low blood flow index were the risk factors for poor delivery outcome of women with scarred uterus. According to the risk factors, the prediction model was obtained: Prob = 1/[1 + e^ (-5.110-2.568 * Pre-delivery Hb - 1.697 * uterine scar grade -2.895 * lower uterine muscle thickness + 19.584 * blood flow index)]. The sensitivity, specificity and area under the curve were 90.0, 91.0 and 0.959, respectively. After validation, the sensitivity and specificity were 85.71 and 87.04, respectively.

CONCLUSION

Low Hb before delivery, low grade of uterine scar, low musculature thickness of lower uterine segment, and low blood flow index were the risk factors for poor delivery outcome of women with scarred uterus. The establishment of prediction model based on risk factors could effectively evaluate the risk of poor delivery outcome of women with scarred uterus.

Prevalence, definition, and etiology of cesarean scar defect and treatment of cesarean scar disorder: A narrative review

Background

Cesarean scar defects (CSD) are caused by cesarean sections and cause various symptoms. Although there has been no previous consensus on the name of this condition for a long time, it has been named cesarean scar disorder (CSDi).

Methods

This review summarizes the definition, prevalence, and etiology of CSD, as well as the pathophysiology and treatment of CSDi. We focused on surgical therapy and examined the effects and procedures of laparoscopy, hysteroscopy, and transvaginal surgery.

Main findings

The definition of CSD was proposed as an anechoic lesion with a depth of at least 2 mm because of the varied prevalence, owing to the lack of consensus. CSD incidence depends on the number of times, procedure, and situation of cesarean sections. Histopathological findings in CSD are fibrosis and adenomyosis, and chronic inflammation in the uterine and pelvic cavities decreases fertility in women with CSDi. Although the surgical procedures are not standardized, laparoscopic, hysteroscopic, and transvaginal surgeries are effective.

Conclusion

The cause and pathology of CSDi are becoming clear. However, there is variability in the prevalence and treatment strategies. Therefore, it is necessary to conduct further studies using the same definitions.

Robot-assisted laparoscopy repair of uterine isthmocele: A two-center observational study

OBJECTIVE

To analyze outcomes and postoperative complications in patients undergoing robot-assisted isthmocele repair.

METHOD

This retrospective cohort study included 33 patients who had robot-assisted laparoscopic surgical management of an isthmocele between September 2013 and August 2020 in two French university hospitals. All charts were reviewed to identify patient characteristics, preoperative and postoperative anatomical findings, complications, and postoperative fertility and symptoms. Patients who had undergone this procedure were asked to complete a telephone questionnaire about their treatment satisfaction and symptoms.

RESULTS

The isthmocele was discovered most often as a result of subfertility (57.6%), but also ectopic pregnancy (18.2%), pelvic pain (15.2%), and postmenstrual bleeding (9.1%). Robot-assisted repair of the isthmocele significantly improved myometrial thickness (from 1.55 mm before surgery to 4.26 mm after surgery [mean difference 2.71; 95% confidence interval, 1.91-3.51], P = 0.0005). Among 20 patients who still desired a child after surgery, 15 became pregnant and 14 had full-term live births. Among the nine patients who had surgery for disabling symptoms, five had no persistent symptoms, three reported global improvement, and one had the same gynecologic discomfort. Seventeen patients agreed to complete the questionnaires (51.5%), and all stated that they would choose to have this surgery again.

CONCLUSION

Robot-assisted repair of an isthmocele is a viable minimally invasive procedure.

Effectiveness, complications, and reproductive outcomes after cesarean scar pregnancy management: a retrospective cohort study

BACKGROUND

There is a dramatic rise in cesarean deliveries worldwide, leading to higher complication rates in subsequent pregnancies. One of these complications is a cesarean scar pregnancy. During the last decades, treatment options for cesarean scar pregnancies have changed, and less invasive interventions have been employed to preserve fertility and reduce morbidity. However, the optimal treatment approach and the influence of various treatments on reproductive outcomes have to be determined.

OBJECTIVE

This study aimed to evaluate the short- and long-term outcomes after cesarean scar pregnancy management.

STUDY DESIGN

We conducted a retrospective cohort study of women determined to have a cesarean scar pregnancy from 2010 to 2021 at a tertiary referral center, the Amsterdam University Medical Center, in the Netherlands. Outcomes of the following management strategies were compared: expectant management, methotrexate, curettage with temporary cervical cerclage, or a laparoscopic niche resection. We performed a curettage if the cesarean scar pregnancy did not cross the serosal line of the uterus, and a laparoscopic niche resection was performed if the cesarean scar pregnancy crossed the serosal line. The main outcomes were treatment efficacy and time to subsequent ongoing pregnancy or pregnancy leading to a live birth.

RESULTS

Of the 60 included women, 5 (8.3%) were managed expectantly, 8 (13.3%) were treated with methotrexate, 31 (51.8%) were treated with a curettage, and 16 (26.7%) with a laparoscopic niche resection. The groups were not comparable. The gestational age and human chorionic gonadotropin levels were generally higher in women who received methotrexate or a laparoscopic niche resection. Additional treatment in the conservative group was needed for 4 (80%) women after expectant management and for 7 (87.5%) women after methotrexate treatment. In the surgical group, all 31 women treated with a curettage and all 16 treated with a laparoscopic niche resection did not require additional treatment. The subsequent ongoing pregnancy rate after cesarean scar pregnancy management was 81.1% (30/37) among women who wished to conceive, with a live birth rate of 78.4% (29/37); 1 woman was in her third trimester of pregnancy at the time of analyses. The time between cesarean scar pregnancy management and subsequent ongoing pregnancy was 4 months (interquartile range, 3-6; P=.02) after expectant management, 18 months (interquartile range, 13-22) after initial methotrexate treatment, 5 months (interquartile range, 3-14; P=.01) after a curettage, and 6 months (interquartile range, 4-15; P=.03) after a laparoscopic niche resection.

CONCLUSION

Surgical treatment of a cesarean scar pregnancy led to a high success rate without additional interventions, high pregnancy rates with a short time interval between treatment, and subsequent pregnancy leading to an ongoing pregnancy or live birth. Conservative management, both with expectant management and methotrexate treatment, led to high (re)intervention rates. Different management approaches are indicated for different types of cesarean scar pregnancies.

Change of the residual myometrial thickness during pregnancy in women who underwent laparoscopic niche resection compared with controls without niche surgery: a prospective comparative cohort study

BACKGROUND

Reduced residual myometrial thickness before and during pregnancy is associated with uterine rupture or dehiscence after vaginal birth after cesarean delivery. Laparoscopic niche resection performed in case of gynecologic symptoms has shown to increase residual myometrial thickness 6 months after surgery.

OBJECTIVE

This study aimed to evaluate the change in residual myometrial thickness from baseline value before pregnancy to the third trimester of pregnancy in women with and without laparoscopic niche resection and evaluate niche presence, niche size during pregnancy vs before pregnancy, and obstetrical outcomes, including uterine rupture and dehiscence in both study groups.

STUDY DESIGN

This was a prospective cohort study conducted in an academic medical center. Of note, 2 groups of pregnant women with a previously diagnosed niche were included: (1) women with a large symptomatic niche (residual myometrial thickness of <3 mm) followed by laparoscopic niche resection (LNR group) and (2) women with a niche without niche resection because of minimal symptoms or a residual myometrial thickness of ≥3 mm diagnosed before current pregnancy (expectant group). Participants underwent a transvaginal ultrasound at 12, 20, and 30 weeks of gestation. Changes in residual myometrial thickness and changes in niche measurements over time were analyzed with linear mixed models.

RESULTS

A total of 100 women were included, 61 in the LNR group and 39 in the expectant group. The change in residual myometrial thickness from baseline value before niche resection to the third trimester of pregnancy was +2.0 mm in the LNR group vs -1.6 mm in the expectant group (P<.001). Residual myometrial thickness decreased from the first trimester of pregnancy onward in both groups. Although residual myometrial thickness was thinner at baseline in the LNR group, it was thicker in the LNR group than in the expectant group during all trimesters: 3.2 mm (P<.001) in the first trimester of pregnancy, 2.5 mm (P<.001) in the second trimester of pregnancy, and 1.8 mm (P=.001) in the third trimester of pregnancy. Uterine dehiscence was reported in 1 of 50 women (2%) in the LNR group and 7 of 36 women (19%) in the expectant group (P=.007) and was related to the depth of niche-to-residual myometrial thickness ratio before pregnancy (after niche resection) and residual myometrial thickness in the second trimester of pregnancy. No uterine rupture was reported. Most patients received a scheduled cesarean delivery in both groups. There was more blood loss during subsequent cesarean delivery in the LNR group than in the expectant group.

CONCLUSION

Here, laparoscopic niche resection resulted in an increased residual myometrial thickness during a subsequent pregnancy. Moreover, a lower number of dehiscence was found in the LNR group than in the expectant group without niche surgery. Per-section blood loss was higher in the LNR group than in the expectant group. In general, laparoscopic niche resection is performed to improve gynecologic symptoms. Currently, there is no evidence to support a laparoscopic niche resection to improve obstetrical outcomes, but the trend toward more uterine dehiscence encourages further research.

Vaginal repair of cesarean section scar defects: Preoperative hysteroscopic evaluation

INTRODUCTION

Cesarean section scar defects (CSDs) are one of the long-term complications following cesarean section. They can be detected by transvaginal sonography, hysterosalpingography, sonohysterography and magnetic resonance imaging (MRI). Hysteroscopy is frequently used in evaluating endometrial disease. However, the description of CSDs by hysteroscopy is very limited. Only a few papers about hysteroscopy evaluation have been published. This is an exploratory study to compare hysteroscopic findings with myometrial thickness and post-surgical outcomes.

MATERIAL AND METHODS

From February 2019 to December 2020, 143 women with CSDs were enrolled in the observational study. All women suffered from abnormal uterine bleeding and were evaluated in a standardized way with hysteroscopy before vaginal surgery. Dome-shaped CSDs could be clearly observed in all patients under hysteroscopy. We recorded the pictures of each patient under hysteroscopy and classified them. All patients underwent outpatient review at 3 and 6 months after surgery to obtain menstrual information and CSD scar size by MRI or transvaginal sonography.

RESULTS

Pale mucosae in the defect were meager endometrial lining covering the surface of muscle layer, cyst lesions were some cyst lesions in the defect, increased local vascularization was a vascular tree with branching and irregular vascular distribution in defect, polypoid lesions were polypoid lesions in the defect, and serrated niches were two niches at the anterior uterine isthmus. The features of the CSDs observed under hysteroscopy were identified as five phenotypes: pale mucosae (90/143, 62.9%), cyst lesions (23/143, 16.1%), polypoid lesions (19/143, 13.3%), increased local vascularization (27/143, 18.9%) and serrated niches (7/143, 4.9%). The most common finding in scar defects under hysteroscopy was pale mucosae in the CSD. The results suggest that patients with increased local vascularization and serrated niches have a high risk of thinner residual myometrium before vaginal repair (p < 0.05). However, there was no significant difference in menstrual duration or in the outcome of vaginal repair for CSDs between these five phenotypes (p > 0.05).

CONCLUSIONS

Patients with the abnormal blood vessel or serration phenotypes of defects under hysteroscopy may have a thinner residual myometrium. The phenotypes of hysteroscopic findings of CSDs have no correlation with the outcome of repair.

Definition of large niche after Cesarean section based on prediction of postmenstrual spotting: Chinese cohort study in non-pregnant women

OBJECTIVE

A large niche after Cesarean section (CS) is associated with long-term complications, of which postmenstrual spotting is associated positively with the size of the niche. However, the diagnosis of a large niche in the literature is inconsistent and the definition is largely subjective. The aim of this study was to generate a definition for a large niche in non-pregnant women based on the presence of postmenstrual spotting.

METHODS

Women who had undergone CS in our hospital between January 2012 and June 2017 were selected randomly from our database, contacted by telephone and subsequently examined between January 2016 and June 2020. Eligible for inclusion were non-pregnant women who had their last CS more than 1 year earlier and agreed to undergo transvaginal sonography (TVS). All participants underwent examination of their CS scar by TVS (two-dimensional color Doppler) during the midfollicular phase. Niche depth, length, width, residual myometrial thickness (RMT), adjacent myometrial thickness (AMT) and ratio of niche depth/AMT were recorded. Women diagnosed with a niche, defined as an indentation at the site of the CS with a depth of at least 2 mm, were classified into two groups (symptomatic or asymptomatic) according to whether they experienced postmenstrual spotting. Logistic regression analysis was used to establish the best cut-off values for the niche parameters to predict postmenstrual spotting. A new definition was generated based on the niche parameters with the highest area under the receiver-operating-characteristics (ROC) curve (AUC) for the prediction of postmenstrual spotting.

RESULTS

A total of 727 women who had a CS > 1 year earlier underwent TVS examination, of whom 263 were diagnosed with a niche (prevalence of 36.2%). Of these, 160 women experienced postmenstrual spotting and 103 were asymptomatic. The three variables with the highest AUC for prediction of postmenstrual spotting were niche depth/AMT ratio (AUC, 0.798; 95% CI, 0.745-0.852), niche depth (AUC, 0.731; 95% CI, 0.668-0.795) and RMT (AUC, 0.683; 95% CI, 0.618-0.748). Based on the best cut-offs according to ROC-curve analysis, a large niche was defined as: niche depth ≥ 0.50 cm, RMT ≤ 0.21 cm or niche depth/AMT ratio ≥ 0.56. The prevalence of a large niche according to this definition was 22.4% (163/727). The new definition had a specificity of 61.17% (95% CI, 52.34-70.41%) and sensitivity of 76.87% (95% CI, 70.28-84.16%) for a large niche.

CONCLUSION

This study has provided a new definition for a large niche after CS. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Fantastic niches and where to find them: the current diagnosis and management of uterine niche

Background

Caesarean section (CS) scar niche is a well recognised complication of caesarean delivery and is defined as an indentation at the site of the CS scar with a depth of at least 2mm.

Objectives

To review systematically the medical literature regarding the current diagnosis and management of uterine niche

Materials and methods

We carried out a systematic review using MeSH terms ‘niche’ OR ‘sacculation’ OR ‘caesarean scar defect’ OR ‘caesarean section scar’ OR ‘uterine defect’ OR ‘isthmocele.’ Articles included were peer-reviewed and in English language.

Main outcome measures

Prevalence, symptoms, diagnosis, pathophysiology and management of uterine niche.

Results

CS scar niche is common and, in a subgroup, produces a range of symptoms including post-menstrual bleeding, dyspareunia and subfertility. It may be linked to use of locked sutures during CS closure. Niche repair can be achieved laparoscopically or hysteroscopically and appears to improve symptoms, although solid conclusions regarding fertility outcomes cannot be drawn.

Conclusions

CS scar niche is associated with a range of symptoms. Repair may aid subfertile patients and those with post-menstrual spotting. The presence of a niche is probably irrelevant in the absence of symptoms.

What is new?

LNG-IUS and surgical repair appear to improve symptoms in those with a niche.

Can uterine niche be prevented?

Uterine niche is a potential significant consequence of Caesarean section and is diagnosed by ultrasound. The timing of Caesarean section (during pre, early or advanced labour), location of the incision (distance from the internal os), techniques for opening and closing the uterine cavity, and bladder flap have been frequently mentioned in the literature, however, these factors continue to be a source of disagreement with respect to whether they increase the risk of uterine niche or protect against this complication. In this review, we outline and discuss the possible risk factors that may be responsible for this entity. The main factor upon which obstetricians can act is the rate of first Caesarean section, which can and should be reduced. Moreover, a rather high incision at a distance from the internal os, and a sparing use of bladder detachment should be always kept in mind as well.

Laparoscopic Isthmocele Repair: Efficacy and Benefits before and after Subsequent Cesarean Section

OBJECTIVE

To evaluate the effect of laparoscopic isthmocele repair on isthmocele-related symptoms and/or fertility-related problems. The residual myometrial thickness before and after subsequent cesarean section was also evaluated.

DESIGN

Retrospective, case series.

SETTING

Public university hospital.

POPULATION

Women with isthmocele (residual myometrium < 5 mm) complaining of abnormal uterine bleeding, chronic pelvic pain or secondary infertility not otherwise specified.

METHODS

Women's complaints and the residual myometrium were assessed pre-operatively and at three to six months post-operatively. In patients who conceived after surgery, the latter was measured at least six months after delivery by cesarean section.

MAIN OUTCOME MEASURES

Resolution of the main symptom three to six months after surgery and persistence of laparoscopic repair benefits after subsequent cesarean section were considered as primary outcome measures.

RESULTS

Overall, 31 women underwent laparoscopic isthmocele repair. The success rates of the surgery as improvement of abnormal uterine bleeding, chronic pelvic pain and secondary infertility were 71.4% (10 of 14), 83.3% (10 of 12) and 83.3% (10 of 12), respectively. Mean residual myometrial thickness increased significantly from 1.77 mm pre-operatively to 6.67 mm, three to six months post-operatively. Mean myometrial thickness in patients who underwent subsequent cesarean section (N = 7) was 4.49 mm. In this sub-group, there was no significant difference between the mean myometrial thickness measured after the laparoscopic isthmocele repair and that measured after the subsequent cesarean section. None of these patients reported recurrence of their symptoms after delivery.

CONCLUSION

Our findings suggest that the laparoscopic isthmocele excision and repair is an appropriate approach for the treatment of isthmocele-related symptoms when done by skilled laparoscopic surgeons. The benefit of this new surgical approach seems to persist even after a subsequent cesarean section. Further investigations and prospective studies are required to confirm this finding.

Novel laparoscopic surgery for the repair of cesarean scar defect without processing scar resection

BACKGROUND

Cesarean scar defect (CSD), especially CSD with residual myometrium less than 3 mm is reported to be the highest risk agent associated with uterine rupture for subsequent pregnancy. Currently, laparoscopic resection and suture was the mainstay therapy method for CSD with a residual myometrium less than 3 mm in women with a desire to conceive. Besides, the women have CSD related symptoms, especially postmenstrual bleeding, should be recommended for CSD treatment. This study is to investigate the efficiency of this novel laparoscopic surgery for the repair of cesarean scar defect (CSD) without scar resection for residual myometrium thickening.

METHOD

This retrospective clinical study enrolled 76 women diagnosed with CSD who had a residual myometrium thickness less than 3 mm and also had a desire to conceive, had undergone laparoscopic surgery for the repair of CSD in the time period March 2016 to March 2018. Two study cohorts were created among the 76 patients: 40 patients had undergone the novel laparoscopic repair of CSD without processing scar resection (Group A), whereas 36 patients had undergone the traditional laparoscopic resection and suture of CSD (Group B).

RESULTS

Residual myometrium thickening occurred among all the 76 patients and the average residual myometrium thickness was increased to almost 6 mm, presenting no between-group difference. In Group A, all the CSD-related postmenstrual bleeding was resolved or improved, but one patient in Group B has no obvious change to postmenstrual bleeding. After CSD repair, 20 patients got pregnant naturally in Group A, and there was no cesarean scar pregnancy and uterine rupture. While, there were 9 cases of natural pregnancy in Group B. No uterine rupture occurred among these 9 pregnant women of Group B, but 1 case of pregnancy was terminated due to cesarean scar pregnancy.

CONCLUSION

Laparoscopic repair without processing scar resection seems to be a feasible, safe and simple operative approach for CSD treatment, which can thicken residual myometrium and improve postmenstrual bleeding.

Laparoscopic management of a full-thickness uterine niche with subsequent pregnancy outcome

Background

Uterine niche is the consequence of impaired healing of the myometrium following a lower segment transverse caesarean section (CS). Although there is conflicting evidence on the management of these cases, laparoscopic repair is a commonly used surgical treatment modality.

Objectives

To demonstrate the management and laparoscopic repair of the niche with subsequent pregnancy outcome.

Materials and Methods

We report a case of a 33-year-old patient who had a significant haematoma in the niche. The haematoma resolved after conservative management however, she remained symptomatic. Therefore, she had a laparoscopic repair. The narrated surgical video article demonstrates the dissection of the uterovesical fold overlying the niche, followed by the excision of the scar tissue and its repair with laparoscopic suturing. Ultrasound and magnetic resonance imaging images of the uterus demonstrating the haematoma at the caesarean section site, the niche after resolution of the haematoma and post-repair imaging are also provided.

Main outcome measures

Repair of the niche, symptomatic relief of abnormal uterine bleeding, spontaneous conception and live birth. Ultrasonographic images also demonstrate uterine wall continuity post laparoscopic repair.

Results

The patient recovered uneventfully. Full-thickness of myometrium was demonstrated with post-operative imaging and confirmed at the subsequent caesarean section. Gynaecological symptoms resolved following the repair. The patient conceived spontaneously after surgery and delivered at term by caesarean section without any complications.

Conclusion

Laparoscopic management of the niche should be considered where there is a complete myometrial defect or significant thinning of the myometrium, especially in symptomatic women who desire future pregnancy.

Uterine Isthmocele-A Frequently Overlooked Complication of Cesarean Sections

Uterine isthmocele or uterine niche is a late complication of cesarean deliveries and causes chronic pelvic pain, menorrhagia or postmenstrual spotting, and infertility. As the number of cesarean sections are constantly increasing, it is important to be aware of this entity so as to make an early diagnosis. This would enable the clinicians to manage these patients efficiently. We present three patients of uterine isthmocele who were evaluated and managed at our institution.

Comparative effectiveness of laparoscopic versus hysteroscopic approach in patients with previous cesarean scar defect: a retrospective cohort study

Background

The aim of this study was to evaluate the clinical effectiveness and obstetric outcomes of laparoscopic and hysteroscopic surgery in patients with previous cesarean scar defect (PCSD).

Methods

A retrospective cohort analysis was performed on women who underwent laparoscopic or hysteroscopic surgery for PCSD from 2016 to 2019 at the Third Xiangya Hospital of Central South University. Among these participants, 13 underwent laparoscopic surgery and 33 received hysteroscopic surgery.

Results

Significant differences were displayed in the operative times (156.9±42.3 vs. 40.7±38.9 min, P<0.05), intra-operative blood loss (80.0±61.0 vs. 17.9±51.2 mL, P<0.05), hospital stay (7.1±1.6 vs. 4.1±2.1 days, P<0.05), postoperative hospital stay (4.3±0.8 vs. 1.5±1.1 days, P<0.05), and hospitalization expenses (22,240.3±249.9 vs. 9,547.1±4,747.2 yuan, P<0.05) between the laparoscopic surgery and hysteroscopic group. No significant difference was observed in the incidence of clinical efficacy between the laparoscopic and hysteroscopic surgery group. A total of 2 of the 4 patients in the laparoscopic surgery group, and 9 of 11 patients in the hysteroscopic surgery group delivered successfully. All 2 participants in the laparoscopic surgery group and 2 participants in the hysteroscopic surgery group were diagnosed with placenta previa. No uterine rupture was reported in our study.

Conclusions

Both laparoscopic and hysteroscopic surgery are safe and effective treatments for PCSD patients, and hysteroscopic surgery is more efficient for PCSD patients.

[Cesarean scare niche: Definition, diagnosis, risk factors, prevention, symptoms, adverse effects, and treatments]

OBJECTIVES

To review the definitions, diagnostic methods, risk factors, symptoms, and treatments for caesarean scar niche.

METHODS

Review of the literature, critical reflection, and pragmatic advice.

RESULTS

There is no consensus on the definition of caesarean scar niche. Some suggest an indentation≥2mm of the myometrium of the caesarean scar, but this is present in more than half of women with caesarean history and takes no account of woman's symptoms. The most popular diagnostic method is ultrasound±hysterosonography. Risks factors for niche are multiple Caesareans, Cesarean during labor with too low incision, and retroverted uterus. Symptoms include abnormal gynaecologic bleeding and pelvic pain, and their presence establish the "Caesarean scar syndrome". The risks of pregnancy with niche is poorly studied, but pregnancy is not contraindicated, even if the niche is untreated. The treatment of caesarean scar niche is mainly surgery and conservative. The former should be reserved for symptomatic patients, and those with secondary infertility and fertility treatment failure. Patients with residual myometrium thickness≥2.5mm may benefit from first-line hysteroscopic treatment, whereas a laparoscopic or vaginal approach could be offered in other cases.

CONCLUSIONS

A pragmatic definition of caesarean scar niche as a disease including symptoms is the necessary prerequisite for the management of women. The treatment is mainly surgical, or conservative depending on the desire for subsequent pregnancy.

Post-Caesarean section niche-related impaired fertility: hypothetical mechanisms

Caesarean section can result in an indentation of the myometrium at the site of the Caesarean scar, called a niche. Niches can cause symptoms of abnormal uterine blood loss, dysmenorrhoea, chronic pelvic pain and dyspareunia and are possibly related to subfertility. Various other explanations for the cause of subfertility after Caesarean section have been proposed in the literature, such as uterine pathology, intra-abdominal adhesions and women’s reproductive choices. Not all niches cause symptoms and the relation with subfertility and a niche in the uterine scar still needs further study since direct evidence is lacking so far. Based on the limited available evidence, and in combination with observations made during sonographic hysteroscopic evaluations and laparoscopic niche repair, we propose and discuss three hypothetical mechanisms: (i) the environment for sperm penetration and implantation may be detrimental; (ii) there could be a physical barrier to embryo transfer and implantation; and (iii) psychogenic factors may reduce the likelihood of pregnancy. Several innovative surgical treatments have been developed and are being implemented for niche-related problems. Promising results are reported, but more evidence is needed before further implementation in daily practice. The additional value of niche resections should be compared to expectant management or fertility therapies, such as ART, in randomized controlled trials. Therefore, our suggested hypotheses should, for the time being, not be used for justification of any specific procedures outside clinical trials.

Post-caesarean Niche (Isthmocele) in Uterine Scar: An Update

Uterine niche is one of the emerging complications of caesarean section. With rising caesarean rates, the caesarean-related iatrogenic complications are also on the rise. These include placenta accreta, scar ectopic pregnancy and uterine niche which is a newer entity being described in the recent literature. Uterine niche, also described as uterine isthmocele, caesarean scar defect and diverticulum, is an iatrogenic defect in the myometrium at the site of previous caesarean scar due to defective tissue healing. Patients may have varied symptoms including abnormal uterine bleeding, post-menstrual spotting and infertility, though many women may be asymptomatic and diagnosed incidentally. Diagnosis is made radiologically by transvaginal sonography, saline instillation sonohysterography or magnetic resonance imaging. Occurrence of niche may be prevented by using correct surgical technique during caesarean. Patients may be managed medically; however, subfertility and persistent symptoms may require surgical correction either by hysteroscopic resection or transabdominal or transvaginal repair. This mini-review comprehensively covers the potential risk factors, clinical presentation, diagnosis and management of this increasingly encountered condition due to rising caesarean rates.

Optimal Isthmocele Management: Hysteroscopic, Laparoscopic, or Combination

OBJECTIVE

To conduct a systematic review of the literature on the hysteroscopic and laparoscopic repair of isthmocele.

DATA SOURCES

A thorough search of the PubMed/Medline, Embase, and Cochrane databases was performed. (PROSPERO registration number CRD42020190668).

METHODS OF STUDY SELECTION

Studies from the last 20 years that addressed isthmocele repair were collected. Both authors screened for study eligibility and extracted data. All prospective and retrospective studies of more than 10 women were included.

TABULATION, INTEGRATION, AND RESULTS

The initial search identified 666 articles (Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow chart) (see Supplemental Fig.). We excluded duplicates, case reports, reviews, video articles, and technique articles. We also excluded studies describing only laparotomy or vaginal repair as these were not in the scope of this review. A total of 31 articles met the inclusion criteria, 21 for hysteroscopic resection and 13 for laparoscopic or combined repair (4 articles tested both modalities and appear in both Tables 1 and 2).For abnormal uterine bleeding, hysteroscopic remodeling relived symptoms in 60% to 100% of cases and laparoscopy in 78% to 94%. Secondary infertility was not evaluated in all studies. After hysteroscopic and laparoscopic treatment, 46% to 100% and 37.5% to 90% of those who wished to conceive became pregnant, after the procedure, respectively. Pain and dysmenorrhea seem to be uncommon. All studies that tested improvement of pain had fewer than 10 women. However, between 66% and 100% of women who complain of pain or dysmenorrhea will note a marked improvement to full resolution.

CONCLUSION

Patients with an isthmocele or cesarean scar defect are usually asymptomatic. For symptomatic women, a repair is a valid option. For those with residual myometrial thickness >2 to 3 mm, hysteroscopic remodeling is the modality of choice with an improvement in abnormal uterine bleeding, secondary infertility, and pain. Women with a residual myometrial thickness <2- to 3-mm laparoscopic repair with simultaneous hysteroscopic guidance show similar results. Because available data are limited, no cutoff for the correct choice between hysteroscopy and laparoscopy can be concluded. We recommend 2.5 mm as the cutoff value based on common practice and expert opinion, although no significance between hysteroscopic and laparoscopic treatment was shown.

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 section one hundred years 1920-2020: the Good, the Bad and the Ugly

In present-day obstetrics, cesarean delivery occurs in one in three women in the United States, and in up to four of five women in some regions of the world. The history of cesarean section extends well over four centuries. Up until the end of the nineteenth century, the operation was avoided because of its high mortality rate. In 1926, the Munro Kerr low transverse uterine incision was introduced and became the standard method for the next 50 years. Since the 1970's, newer surgical techniques gradually became the most commonly used method today because of intraoperative and postpartum benefits. Concurrently, despite attempts to encourage vaginal birth after previous cesareans, the cesarean delivery rate increased steadily from 5 to 30-32% over the last 10 years, with a parallel increase in costs as well as short- and long-term maternal, neonatal and childhood complications. Attempts to reduce the rate of cesarean deliveries have been largely unsuccessful because of the perceived safety of the operation, short-term postpartum benefits, the legal climate and maternal request in the absence of indications. In the United States, as the cesarean delivery rate has increased, maternal mortality and morbidity have also risen steadily over the last three decades, disproportionately impacting black women as compared to other races. Extensive data on the prenatal diagnosis and management of cesarean-related abnormal placentation have improved outcomes of affected women. Fewer data are available however for the improvement of outcomes of cesarean-related gynecological conditions. In this review, the authors address the challenges and opportunities to research, educate and change health effects associated with cesarean delivery for all women.

Reduced pregnancy and live birth rates after in vitro fertilization in women with previous Caesarean section: a retrospective cohort study

STUDY QUESTION

Does a previous Caesarean section affect reproductive outcomes, including live birth, in women after IVF or ICSI?

SUMMARY ANSWER

A previous Caesarean section impairs live birth rates after IVF or ICSI compared to a previous vaginal delivery.

WHAT IS KNOWN ALREADY

Rates of Caesarean sections are rising worldwide. Late sequelae of a Caesarean section related to a niche (Caesarean scar defect) include gynaecological symptoms and obstetric complications. A systematic review reported a lower pregnancy rate after a previous Caesarean section (RR 0.91 CI 0.87-0.95) compared to a previous vaginal delivery. So far, studies have been unable to causally differentiate between problems with fertilisation, and the transportation or implantation of an embryo. Studying an IVF population allows us to identify the effect of a previous Caesarean section on the implantation of embryos in relation to a previous vaginal delivery.

STUDY DESIGN, SIZE, DURATION

We retrospectively studied the live birth rate in women who had an IVF or ICSI treatment at the IVF Centre, Amsterdam UMC, location VUmc, Amsterdam, the Netherlands, between 2006 and 2016 with one previous delivery. In total, 1317 women were included, of whom 334 had a previous caesarean section and 983 had previously delivered vaginally.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All secondary infertile women, with only one previous delivery either by caesarean section or vaginal delivery, were included. If applicable, only the first fresh embryo transfer was included in the analyses. Patients who did not intend to undergo embryo transfer were excluded. The primary outcome was live birth. Multivariate logistic regression analyses were used with adjustment for possible confounders ((i) age; (ii) pre-pregnancy BMI; (iii) pre-pregnancy smoking; (iv) previous fertility treatment; (v) indication for current fertility treatment: (a) tubal, (b) male factor and (c) endometriosis; (vi) embryo quality; and (vii) endometrial thickness), if applicable. Analysis was by intention to treat (ITT).

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline characteristics of both groups were comparable. Live birth rates were significantly lower in women with a previous caesarean section than in women with a previous vaginal delivery, 15.9% (51/320) versus 23.3% (219/941) (OR 0.63 95% CI 0.45-0.87) in the ITT analyses. The rates were also lower for ongoing pregnancy (20.1 versus 28.1% (OR 0.64 95% CI 0.48-0.87)), clinical pregnancy (25.7 versus 33.8% (OR 0.68 95% CI 0.52-0.90)) and biochemical test (36.2 versus 45.5% (OR 0.68 95% CI 0.53-0.88)). The per protocol analyses showed the same differences (live birth rate OR 0.66 95% CI 0.47-0.93 and clinical pregnancy rate OR 0.72 95% CI 0.54-0.96).

LIMITATIONS, REASONS FOR CAUTION

This study is limited by its retrospective design. Furthermore, 56 (16.3%) cases lacked data regarding delivery outcomes, but these were equally distributed between the two groups.

WIDER IMPLICATIONS OF THE FINDINGS

The lower clinical pregnancy rates per embryo transfer indicate that implantation is hampered after a caesarean section. Its relation with a possible niche (caesarean scar defect) in the uterine caesarean scar needs further study. Our results should be discussed with clinicians and patients who consider an elective caesarean section.

STUDY FUNDING/COMPETING INTEREST(S)

Not applicable.

TRIAL REGISTRATION NUMBER

This study has been registered in the Dutch Trial Register (Ref. No. NL7631 http://www.trialregister.nl).

From hysteroscopy to laparoendoscopic surgery: what is the best surgical approach for symptomatic isthmocele? A systematic review and meta-analysis

PURPOSE

To investigate the effectiveness and risks of different surgical therapies for isthmocele in symptomatic women with abnormal uterine bleeding, infertility, or for the prevention of obstetric complications, considering safety and surgical complications.

METHODS

PubMed/MEDLINE, Scopus, Embase, Science Direct, and Cochrane Library were systematically searched (n° CRD4201912035) for original articles on the surgical treatment of isthmocele published between 1950 and 2018. Data synthesis was completed using MedCalc 16.4.3. The body of evidence was assessed using the GRADE methodology.

RESULTS

We retrieved 33 publications: 28 focused on a single surgical technique, and five comparing different techniques. Meta-analysis showed an improvement of symptoms in 85.00% (75.05-92.76%) of women after hysteroscopic correction, 92.77% (85.53-97.64%) after laparoscopic/robotic correction, and 82.52% (67.53-93.57%) after vaginal correction. Hysteroscopic surgery was associated with the lowest risk of complications (0.76%, 0.20-1.66%).

CONCLUSIONS

We found adequate evidence supporting the use of surgery for the treatment of symptomatic isthmocele, as it was found to improve the bleeding symptoms in more than 80% of patients. Differently, we found a lack of evidence regarding the role of surgery with the purpose of improving fertility or reducing the risk of obstetric complications in women with asymptomatic isthmocele. The hysteroscopic correction of isthmocele may be the safest and most effective strategy in those patients with adequate residual myometrial thickness overlying the isthmocele. Laparoscopic and vaginal surgeries may be the preferred options for patients with a thinner residual myometrium over the defect (< 2.5 mm) and when hysteroscopic treatment is inconclusive.

Niche-related outcomes after caesarean section and quality of life: a focus group study and review of literature

Background

A niche in the uterus, present in 60% of women after caesarean section (CS), is associated with several gynaecological symptoms and possibly with subfertility. Studies that focus on quality of life (QoL) in relation to a niche are lacking.

Purpose

To identify niche-related outcomes that influence QoL and to compare patient-reported outcomes with outcomes studied in the literature.

Methods

Two focus group discussions (FGDs, N = 8 and 5) were conducted in Amsterdam UMC—location VUmc. Participants were Dutch patients with a large niche, with (planned) surgical treatment for their symptoms. Niche-related symptoms and impact on functioning or participation were fixed topics. The transcripts of the FGDs were coded into outcomes, themes and domains of QoL according to the WHOQOL model. Additionally, participants created a top five important outcomes. Next, we performed a systematic review (SR) on niche-related outcomes and compared the FGDs with niche-related outcomes from the SR.

Results

In four domains (physical health, psychological domain, social relationships and environment), fifteen themes were reported in the FGDs. Abnormal uterine bleeding (AUB), subfertility, sexual activity, abdominal pain and self-esteem were themes prioritised by participants. In the literature, gynaecological symptoms and reproductive outcomes were predominantly studied. Sexuality and self-esteem were prioritised in the FGDs but hardly or never studied in the literature.

Conclusion

We found a broad range of niche-related outcomes influencing QoL. Apart from symptoms evaluated in the literature such as AUB, abdominal pain and subfertility, clinicians and researchers should be more aware of sexual activity and self-esteem in this population.

Electronic supplementary material

The online version of this article (10.1007/s11136-019-02376-6) contains supplementary material, which is available to authorized users.

Intrauterine device (IUD) migration in cesarean delivery scar: What to do with the niche?

BACKGROUND

The presence of a niche after cesarean section is a common and mostly asymptomatic finding. However, it can cause symptoms or result in impaired fertility or obstetric complications in following pregnancies. At present there is no uniform consensus on when to treat and which way of repair is most suitable. The aim of this systematic review of literature was to provide an overview of current knowledge about cesarean scar niches and about the modalities of niche repair.

METHODS

On the second of January 2019 Pubmed and Cochrane databases were searched for relevant studies published until December 2018. Search terms were cesarean scar defect, niche, niche repair. As combination key words `hysteroscopy ´, `laparoscopy ´ and `vaginal repair ´ were used.

RESULTS

Eight articles were included in this review. The publications were very heterogeneous. Most of them stated that hysteroscopic niche repair with resection of the lower (and upper) rim is suggested for abnormal uterine bleeding. In symptomatic women who wish to conceive, different authors suggest laparoscopic niche repair with double layer closure to increase myometrial thickness. Also, one report on vaginal repair was included, none of the included patients had child wish. Nothing was reported on residual myometrial thickness after surgery.

CONCLUSION

The current literature is not sufficient to draw strong conclusions on what to do about cesarean scar niches, yet, they justify the role of hysteroscopic as well as laparoscopic niche repair dependent on different pre- operative factors. We conclude that further large randomized controlled trials are necessary.

Isthmocele: an overview of diagnosis and treatment

An isthmocele, a cesarean scar defect or uterine niche, is any indentation representing myometrial discontinuity or a triangular anechoic defect in the anterior uterine wall, with the base communicating to the uterine cavity, at the site of a previous cesarean section scar. It can be classified as a small or large defect, depending on the wall thickness of the myometrial deficiency. Although usually asymptomatic, its primary symptom is abnormal or postmenstrual bleeding, and chronic pelvic pain may also occur. Infertility, placenta accrete or praevia, scar dehiscence, uterine rupture, and cesarean scar ectopic pregnancy may also appear as complications of this condition. The risk factors of isthmocele proven to date include retroflexed uterus and multiple cesarean sections. Nevertheless, factors such as a lower position of cesarean section, incomplete closure of the hysterotomy, early adhesions of the uterine wall and a genetic predisposition may also contribute to the development of a niche. As there are no definitive criteria for diagnosing an isthmocele, several imaging methods can be used to assess the integrity of the uterine wall and thus diagnose an isthmocele. However, transvaginal ultrasound and saline infusion sonohysterography emerge as specific, sensitive and cost-effective methods to diagnose isthmocele. The treatment includes clinical or surgical management, depending on the size of the defect, the presence of symptoms, the presence of secondary infertility and plans of childbearing. Surgical management includes minimally invasive approaches with sparing techniques such as hysteroscopic, laparoscopic or transvaginal procedures according to the defect size.

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

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.

Isthmocele: From Risk Factors to Management

OBJECTIVE

 The aim of the present study was to perform a comprehensive review of the literature to provide a complete and clear picture of isthmocele-a hypoechoic area within the myometrium at the site of the uterine scar of a previous cesarean section-by exploring in depth every aspect of this condition.

METHODS

 A comprehensive review of the literature was performed to identify the most relevant studies about this topic.

RESULTS

 Every aspect of isthmocele has been studied and described: pathophysiology, clinical symptoms, classification, and diagnosis. Its treatment, both medical and surgical, has also been reported according to the actual literature data.

CONCLUSION

 Cesarean section is the most common surgical procedure performed worldwide, and one of the consequences of this technique is isthmocele. A single and systematic classification of isthmocele is needed to improve its diagnosis and management. Further studies should be performed to better understand its pathogenesis.

Laparoscopic Resection of Post-Cesarean Section Scar Uterine Cyst

STUDY OBJECTIVE

To demonstrate a technique of performing laparoscopic resection of a post-cesarean section scar uterine cyst.

DESIGN

Technical video (Canadian Task Force classification III).

SETTING

University Hospital.

PATIENT

A 38-year old woman.

INTERVENTION

Laparoscopic excision of a uterine cyst within a cesarean section scar.

MEASUREMENTS AND MAIN RESULTS

A 38-year-old woman presented with secondary subfertility requesting removal of a cesarean section scar defect to prepare the uterine cavity for in vitro fertilization. Preoperative ultrasound demonstrated a 17.7 × 12.2 mm scar defect. At rigid hysteroscopy the anterior uterine wall cyst was observed and noted to be narrowing the uterine cavity. A laparoscopic approach was used to excise the uterine cyst. We carefully mobilized the bladder from its adhesions at the site of the previous cesarean section scar. The uterine cyst was located and margins of the defect identified. An ultrasonic-energy device was used to enucleate and excise the cyst. A uterine manipulator helped to identify the cervical canal and protect the posterior wall from inadvertent suture placement. The defect was closed with 1 vicryl interrupted sutures, being careful to incorporate the full thickness of the uterine wall to an able maximal opposition. An adhesion barrier was applied to the area. Transvaginal ultrasound scanning performed 6 weeks postoperatively demonstrated full healing with no residual defect.

CONCLUSION

Niches are recognized complications of cesarean sections resulting from incomplete healing of the scar and more likely in single-layer closures [1]. They can be associated with postmenstrual spotting, dysmenorrhea, chronic pain, subfertility, and poorer reproductive and obstetric outcomes [1-5]. Laparoscopic resection of niches is well established, showing symptomatic relief and an increase in residual myometrium [6]. Although cesarean section scar defects have been described as niches, we presented a further variety of defect that has not been previously described, a uterine cyst.

The effect of laparoscopic resection of large niches in the uterine caesarean scar on symptoms, ultrasound findings and quality of life: a prospective cohort study

Objective

To evaluate the effectiveness of a laparoscopic niche resection on niche‐related symptoms and/or fertility‐related problems, ultrasound findings and quality of life.

Design

Prospective cohort study.

Setting

University hospital.

Population

Women with a large niche (residual myometrium <3 mm) and complaints of either postmenstrual spotting, dysmenorrhoea, intrauterine fluid accumulation and/or difficulties with embryo transfer due to distorted anatomy.

Methods

Women filled out questionnaires and a validated menstrual score chart at baseline and 6 months after the laparoscopic niche resection. At baseline and between 3 and 6 months follow up niches were evaluated by transvaginal ultrasound.

Main outcome measures

The primary outcome was reduction of the main problem 6 months after the intervention. Secondary outcomes were complications, menstrual characteristics, dysmenorrhoea, niche measurements, intrauterine fluid, surgical outcomes, satisfaction and quality of life.

Results

In all, 101 women underwent a laparoscopic niche resection. In 80 women (79.2%) the main problem was improved or resolved. Postmenstrual spotting was significantly reduced by 7 days at 6 months follow up compared with baseline. Dysmenorrhoea and discomfort related to spotting was also significantly reduced. The residual myometrium was increased significantly at follow up. The intrauterine fluid was resolved in 86.9% of the women with intrauterine fluid at baseline; 83.3% of women were (very) satisfied. The physical component of quality of life increased, the mental component did not change.

Conclusions

A laparoscopic niche resection reduced postmenstrual spotting, discomfort due to spotting, dysmenorrhoea and the presence of intrauterine fluid in the majority of women and increased the residual myometrium.

Tweetable abstract

Laparoscopic niche resection reduces niche‐related problems and enlarges the residual myometrium.

Laparoscopic niche resection reduces niche‐related problems and enlarges the residual myometrium.