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

Isthmoceles - Accuracy of imaging diagnosis and clinical correlation with histology: A prospective cohort study

Background

Isthmoceles are a growing clinical concern.

Objectives

To evaluate the accuracy of diagnosis of isthmoceles by imaging and to correlate the dimensions with clinical symptoms and histopathology.

Materials and Methods

Prospective study of women (n=60) with ≥1 C-section undergoing hysterectomy. Isthmoceles were measured by imaging before surgery and macroscopically on the specimen after hysterectomy, followed by histological analysis.

Main outcome measures

Accuracy of isthmocele diagnosis, correlation with clinical symptoms, and histopathological findings.

Result

By imaging, isthmoceles were slightly deeper (P=0.0176) and shorter (P=0.0045) than macroscopic measurements. Differences were typically small (≤3mm). Defined as an indentation of ≥2 mm at site of C-section scar, imaging diagnosed 2 isthmoceles consequently not seen by histology and missed 3. Number of prior C-sections increased isthmocele severity but neither the incidence nor the remaining myometrial thickness (RMT) did. Severity correlated positively with symptoms and histology. However, clinical use was limited. Histological analysis revealed presence of thick wall vessels in 100%, elastosis in 40%, and adenomyosis in 38%. Isthmocele lining was asynchronous with the menstrual phase in 31%.

Conclusions

Dimensions of isthmoceles by imaging were largely accurate with occasionally large differences observed. Number of C-sections did not increase isthmocele incidence, only severity. Indication for surgery remains clinical, considering dimensions and symptoms.

What is new?

Dimensions of isthmoceles should be confirmed before surgery since uterine contractions might change those dimensions. Symptoms increase with dimensions of isthmoceles but are not specific. Endometrial lining within the isthmocele can be asynchronous with the menstrual phase.

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.

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.

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.

Comparing levonorgestrel intrauterine system with hysteroscopic niche resection in women with postmenstrual spotting related to a niche in the uterine cesarean scar: a randomized, open-label, controlled trial

BACKGROUND

Postmenstrual spotting and chronic pelvic pain after cesarean delivery are associated with the presence of niches. Levonorgestrel intrauterine system (52 mg) and hysteroscopic niche resection have been shown to relieve niche-related symptoms at 6 months after the intervention.

OBJECTIVE

This trial aimed to compare the effectiveness of 52-mg levonorgestrel intrauterine system with that of hysteroscopic niche resection in reducing niche-related postmenstrual spotting.

STUDY DESIGN

This randomized, open-label, controlled trial was conducted at a medical center in Shanghai, China. Women with symptoms of postmenstrual spotting after cesarean delivery, with a niche depth of at least 2 mm and residual myometrium of at least 2.2 mm on magnetic resonance imaging, and no intention to conceive within the next year were randomly assigned to receive treatment with 52-mg levonorgestrel intrauterine system or hysteroscopic niche resection. The primary outcome was the reduction in postmenstrual spotting at 6 months after randomization, defined as the percentage of women with a reduction of at least 50% in spotting days relative to baseline. Efficacy and safety were assessed using intention-to-treat analysis.

RESULTS

Between September 2019 and January 2022, 208 women were randomized into the levonorgestrel intrauterine system group (N=104) or the hysteroscopic niche resection group (N=104). At the 6-month follow-up, a 50% reduction in spotting had occurred in 78.4% (80/102) of women in the levonorgestrel intrauterine system group and in 73.1% (76/104) of women in the hysteroscopic niche resection group (relative risk, 1.07 [95% confidence interval, 0.92-1.25]; P=.370). Spotting decreased over time (Ptrend=.001), with a stronger reduction observed in the levonorgestrel intrauterine system group (P=.001). There was also a significant interaction between time and treatment (P=.007). From 9 months onward, a more significant reduction in spotting was observed in the levonorgestrel intrauterine system group than in the hysteroscopic niche resection group (9 months, 89.2% vs 72.1%; relative risk, 1.24 [95% confidence interval, 1.08-1.42]; 12 months, 90.2% vs 70.2%; relative risk, 1.29 [95% confidence interval, 1.12-1.48]). Moreover, compared with the hysteroscopic niche resection group, the levonorgestrel intrauterine system group had significantly fewer postmenstrual spotting days and total bleeding days from 6 months onward (all P<.001), and less pelvic pain from 3 months onward (all P<.010). No intervention-related complications were reported in any group. During follow-up, 11 (10.8%) women reported hormone-related side effects, and 2 women (2.0%) in the levonorgestrel intrauterine system group had spontaneous partial expulsion. Meanwhile, 3 unintended pregnancies were reported in the hysteroscopic niche resection group.

CONCLUSION

In women with niche-related postmenstrual spotting, the levonorgestrel intrauterine system was not more effective than hysteroscopic niche resection in reducing the number of spotting days by at least 50% at 6 months. However, the levonorgestrel intrauterine system was superior in reducing spotting from 9 months onward, and it reduced the absolute number of spotting days from 6 months onward and pelvic pain from 3 months onward.

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.

Comparative effectiveness of transvaginal repair vs. hysteroscopic resection in patients with symptomatic uterine niche

Objective

To compare the efficacy of transvaginal repair and hysteroscopic resection in improving niche associated postmenstrual spotting.

Methods

The improvement rate of postmenstrual spotting in women who underwent transvaginal repair or hysteroscopic resection treatment was assessed retrospectively in patients accepted at the Niche Sub-Specialty Clinic in International Peace Maternity and Child Health Hospital between June 2017 and June 2019. Postoperative spotting symptom within one year after surgery, pre- and postoperative anatomical indicators, women' satisfaction with menstruation and other perioperative parameters were compared between the two groups.

Results

68 patients in the transvaginal group and 70 patients in the hysteroscopic group were included for analysis. The improvement rate of postmenstrual spotting in the transvaginal group at the 3rd, 6th, 9th, and 12th months after surgery was 87%, 88%, 84%, and 85%, significantly higher than 61%, 68%, 66%, and 68% in the hysteroscopic group, respectively (P < 0.05). The total days of spotting improved significantly at the 3rd month after surgery but did not change over time within one year in each group (P > 0.05). After surgery, the disappearance rates of the niche are 68% in transvaginal group and 38% in hysteroscopic group, however, hysteroscopic resection had shorter operative time and hospitalization duration, less complications, and lower hospitalization costs.

Conclusion

Both treatments can improve the spotting symptom and anatomical structures of uterine lower segments with niches. Transvaginal repair is better in thickening the residual myometrium than hysteroscopic resection, however, hysteroscopic resection has shorter operative time and hospitalization duration, less complications, and lower hospitalization costs.

A case report of an endometriosis cyst at cesarean scar defect and review of literature

BACKGROUND

Cesarean scar defect (CSD) presents as a cystic defect that connects the uterine cavity at the site of the previous cesarean section (CS). Endometriosis refers to the discovery of endometrial glands and stroma outside the uterine cavity. Cases of endometriosis cysts at CSD have not been reported.

CASE PRESENTATION

In this article, we will present a patient with an endometriosis cyst at CSD with symptoms of a prolonged menstrual cycle, periods without cyclic abdominal pain, and a history of cesarean delivery. The gynecologic ultrasound showed a CSD and a mixed mass in the right front of the uterus. After about 1 month, the tumor grew from a diameter of 4.75 cm to 8.06 × 6.23 × 3.66 cm. The patient eventually had an operation, which revealed a mass protruding from the incision in the anterior uterine wall, which was attached to the anterior uterine wall by a thin tip with a smooth surface. Intraoperative rapid cytopathology suggested that endometrial glands were seen within the smooth muscle tissue, similar to endometriosis. Subsequently, the patient underwent resection of the endometriotic cyst. Final paraffin pathology showed smooth muscle with visible endometrial glands and old hemorrhage, and a one-year follow-up showed no recurrence of endometriosis cysts at CSD.

CONCLUSIONS

Endometriosis cysts at CSD are very rare. The clinical symptoms may be less obvious, and the diagnosis relies mainly on the patient's previous surgical history and imaging. A finding of a pelvic mass in the location of the CSD, with or without symptoms of menstrual changes and intermittent abdominal pain, should be considered an endometriotic cyst at CSD. Surgical treatment is a good choice for this disease. Further studies are needed regarding the etiological mechanism of this case and why the mass enlarged rapidly in one mouth.

Adjunctive azithromycin prophylaxis protects women from uterine cesarean scar defect: A randomized controlled trial

INTRODUCTION

Cesarean scar defect (CSD) is a long-term outcome of cesarean section (CS) and associated with numerous gynecological and obstetric problems. Previous studies indicate that infection may be a risk factor for CSD. Adjunctive azithromycin was shown to reduce the risk of postoperative infection in patients undergoing non-elective primary cesarean delivery in labor or after the rupture of membranes compared with standard antibiotic prophylaxis. This study investigated the protective effect of adjunctive azithromycin in combination with single-dose cephalosporin against CSD in women undergoing non-elective cesarean delivery.

MATERIAL AND METHODS

A randomized, double-blind, controlled clinical trial was conducted in a University hospital in Shanghai, China. A total of 242 women who underwent their first non-elective CS were randomly assigned to receive 1500 mg cefuroxime sodium plus 500 mg intravenous azithromycin (n = 121; experimental group) or 1500 mg cefuroxime sodium plus a placebo (n = 121; placebo group). The primary outcome was CSD prevalence, as determined by transvaginal ultrasound and saline infusion sonohysterography within 6 months of delivery. Secondary outcomes were changes in infectious indicators (e.g. hypersensitive C-reactive protein and procalcitonin), postoperative morbidity, and use of postoperative antibiotics. We also examined the operative procedure, pathogenic microorganism cultures, and fetal outcomes. Outcomes were compared between groups with the chi-squared test, Fisher's exact test, or Student's t test.

RESULTS

Between May 2018 and May 2021, 121 women were randomized to each arm. Because the sonographic follow up was disrupted by the coronavirus disease 2019 pandemic and strict management policies, we merged the follow-up time points (6 weeks and 6 months) into a single time period (6 weeks to 6 months); 104 and 108 women in the experimental and placebo groups, respectively, completed the first sonographic follow up. CSD was diagnosed by sonography in 34/104 (32.7%) and 50/108 (46.3%) patients in the experimental and placebo groups, respectively (relative risk 0.71, 95% confidence interval 0.50-0.99; p = 0.043). Characteristics of CSD and short-term infection outcomes did not differ between groups.

CONCLUSIONS

A single dose of intravenous 500 mg azithromycin adjunctive to single-dose cefuroxime prophylaxis significantly reduced the incidence of CSD in women undergoing non-elective CS.

Risk analysis of poor wound healing in forceps delivery

AIM

This study aims to explore the risk factors leading to poor wound healing after forceps delivery.

METHOD

In this retrospective study, 74 patients undergoing forceps delivery with poor wound healing were compared with contemporary randomly selected 74 patients undergoing forceps delivery but with normal wound healing.

RESULTS

Compared to the normal healing group, the poor healing group had larger birthweight (p = 0.01), longer labor length (805.9 ± 356.4 min vs. 572.9 ± 306.3 min, p < 0.001), more virginal checks (4.0 ± 1.5 vs. 3.4 ± 1.7, p = 0.029), and more contaminated amniotic fluid (p = 0.043). More patients in poor healing group suffered from postpartum fever (52.7% vs. 21.6%, p < 0.001), postpartum hemorrhage (p < 0.001), and anemia after delivery (p < 0.001). Labor length (odds ratio (OR) 1.125, 95% confidence interval [CI] = 1.033-1.226), anemia after delivery (OR 3.621, 95% CI = 2.077-6.314), postpartum fever (OR 7.100, 95% CI = 2.505-20.124), and degree of laceration (OR 3.067, 95% CI = 1.258-7.479) were the risk factors of poor healing of perineal wound after forceps delivery, while postpartum antibiotics (OR 0.303, 95% CI = 0.098-0.937) and suture removal days (OR 0.272, 95% CI = 0.133-0.556) were the protective factors.

CONCLUSION

To promote the wound healing from the forceps delivery, obstetricians may consider to control the patient's labor length and degree of laceration, increase patient's nutrition, apply prophylactic antibiotics, and prolong the suture removal days.

[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.

Effectiveness of hysteroscopic resection of a uterine caesarean niche can be predicted: a prospective cohort study

This study aimed to develop and validate a model for the preoperative prediction of the effectiveness of hysteroscopic resection of a uterine cesarean niche in patients with postmenstrual spotting. The predictive model was developed in a primary prospective cohort consisting of 208 patients with niche treated by hysteroscopic resection. Multivariable logistic regression analysis was performed to develop the predictive model, which incorporated preoperative menstrual characteristics and magnetic resonance imaging (MRI) findings. Surgical efficacy was defined as a decrease in postmenstrual spotting duration of at least 3 days at the 3-month follow-up compared with baseline. The predictive model was presented with a nomogram, and the performance was assessed with respect to its calibration, discrimination, and clinical use. Internal validation was performed using tenfold cross-validation. The predictive factors in the final model were as follows: preoperative menstrual duration, thickness of the residual myometrium (TRM), length, TRM/thickness of the adjacent myometrium ratio, angle γ, area, and presence of a lateral branch of the niche. The model showed good performance in predicting the effectiveness of hysteroscopic niche resection. Incorporating the preoperative duration of the menstrual period and MRI findings of the niche into an easy-to-use nomogram facilitates the individualized prediction of the effectiveness of a hysteroscopic niche resection by 26 Fr resectoscope, but multicenter prospective studies are needed to validate it.

Efficacy of adjunctive azithromycin versus single-dose cephalosporin prophylaxis for caesarean scar defect: study protocol for a randomised controlled trial

INTRODUCTION

Perioperative infections may be considered predictors of caesarean scar defect (CSD), and multidose antibiotics have a protective effect against CSD. However, the ability of adjunctive azithromycin combined with cephalosporin to reduce the prevalence of CSD remains unclear. The planned study aims to clarify the protective effect of antibiotics against CSD and to assess the effectiveness of adjunctive azithromycin prophylaxis for CSD.

METHODS AND ANALYSIS

This study is a double-blind, parallel-control randomised clinical trial that will be carried out at the International Peace Maternity and Child Health Hospital. A total of 220 eligible patients will be randomised (1:1) to receive either adjunctive azithromycin or single-dose cephalosporin 30 min before the incision. The evaluation criteria are the prevalence and characteristics of CSD as assessed by transvaginal ultrasound (TVU) and saline infusion sonohysterography (SIS) at 42 days, 6 months and 12 months after delivery. The primary outcome will be the prevalence of CSD, and the characteristics of CSD will be assessed by TVU and SIS 42 days after delivery; all other outcomes are secondary.

ETHICS AND DISSEMINATION

This protocol received authorisation from the Medical Research Ethics Committee of International Peace Maternity and Child Health Hospital on 25 April 2018 (approval no. GKLW2017-84). The findings will be reported in peer-reviewed publications and presentations at international scientific meetings.

TRIAL REGISTRATION NUMBER

ChiCTR-INR-17013272.