Vaginal Ultrasonographic and Hysterosonographic Evaluation of the Low Transverse Incision after Caesarean Section: Correlation with Gynaecological Symptoms

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.

Cesarean scar defects and abnormal uterine bleeding: a systematic review and meta-analysis

OBJECTIVE

To synthesize the published literature to better understand the association between cesarean scar defects (CSDs) and abnormal uterine bleeding (AUB). In particular, we aimed to evaluate the risk and pattern(s) of CSD-associated AUB in addition to exploring the relationship between defect morphology with bleeding symptoms.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Patients with CSD and reports of uterine bleeding as an outcome were identified in 60 studies from database searches.

INTERVENTIONS

Studies that investigated CSD (as defined by investigators) and reported uterine bleeding, menstrual bleeding, or AUB as an outcome were included.

MAIN OUTCOME MEASURES

The prevalence and risk of AUB (intermenstrual, postmenstrual, and unscheduled bleeding) in patients with confirmed CSD.

RESULTS

Nine studies reported on the prevalence of AUB in patients with a confirmed CSD. Patients with CSD were more likely to experience AUB, compared with those without CSD (relative risk, 3.47; 95% confidence interval [CI], 2.02-5.97; 6 studies, 1,385 patients; I² = 67%). In a population of patients with at least 1 cesarean delivery, the prevalence of AUB in those with CSD was 25.5% (95% CI, 14.7-40.5; 6 studies, 667 patients, I² = 93%). However, symptom prevalence was much higher in patients presenting for imaging for a gynecologic indication where the prevalence of AUB in the presence of a CSD was 76.4% (95% CI, 67.8-83.3; 5 studies, 505 patients; I² = 71%). The mean menstrual duration in symptomatic patients with CSD was 13.4 days (95% CI, 12.6-14.2; 19 studies, 2,095 patients; I² = 96%), and the mean duration of early-cycle intermenstrual bleeding was 6.8 days (95% CI, 5.7-7.8 days; 9 studies, 759 patients; I² = 93%). The most common descriptor of CSD-associated AUB was "brown discharge". Patients with larger CSD experienced more bleeding symptoms.

CONCLUSION

There is a strong and consistent association between patients with CSD and AUB. These patients experience a unique bleeding pattern, namely prolonged menstruation and early-cycle intermenstrual bleeding. These data should provide impetus for including CSD as a distinct entity in AUB classification systems. High heterogeneity in our results calls for standardization of nomenclature and outcome reporting for this condition.

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.

Hysteroscopic management of caesarean scar defects

A caesarean section may lead to a defect of the myometrium at the site of the uterine scar. The association with abnormal uterine bleeding or impaired fertility has been demonstrated. Hysteroscopic remodelling reportedly reduces the symptoms. To review the available literature reporting on hysteroscopic treatment of these defects in symptomatic women with abnormal uterine bleeding or impaired fertility. A systematic search of PubMed and Cochrane databases has been performed until January 2021, including 27 articles. Hysteroscopic remodelling relieved symptoms of abnormal uterine bleeding in 60-100% and 25-100% of women with impaired fertility conceived within the follow up period. No major complications were reported. Hysteroscopic remodelling seems a treatment option in the management of symptomatic caesarean scar defects. Long-term follow-up and larger studies are needed to evaluate the effect on abnormal uterine bleeding as well as on reproductive outcomes.

Evaluation of uterine scar healing by transvaginal ultrasound in 607 nonpregnant women with a history of cesarean section

BACKGROUND

Caesarean scar defect (CSD) seriously affects female reproductive health. In this study, we aim to evaluate uterine scar healing by transvaginal ultrasound (TVS) in nonpregnant women with cesarean section (CS) history and to build a predictive model for cesarean scar defects is very necessary.

METHODS

A total of 607 nonpregnant women with previous CS who have transvaginal ultrasound measurements of the thickness of the lower uterine segment. The related clinical data were recorded and analyzed.

RESULTS

All patients were divided into two groups according to their clinical symptoms: Group A (N = 405) who had no cesarean scar symptoms, and Group B (N = 141) who had cesarean scar symptoms. The difference in frequency of CS, uterine position, detection rate of CSD and the residual muscular layer (TRM) of the CSD were statistically significant between groups; the TRM measurements of the two groups were (mm) 5.39 ± 3.34 versus 3.22 ± 2.33, P < 0.05. All patients were divided into two groups according to whether they had CSDs: Group C (N = 337) who had no CSDs, Group D (N = 209) who had CSDs on ultrasound examination. The differences in frequency of CS, uterine position, TRM between groups were statistically significant (P < 0.05). In the model predicting CSDs by TRM with TVS, the area under the ROC curve was 0.771, the cut-off value was 4.15 mm. The sensitivity and specificity were 87.8% and 71.3%, respectively.

CONCLUSIONS

Patients with no clinical symptoms had a mean TRM on transvaginal ultrasonography of 5.39 ± 3.34 mm, which could be used as a good reference to predict the recovery of patients with CSDs after repair surgery.

Gynecological outcomes of uterine niche after cesarean section: A descriptive study

Objectives:

Our aim was to study the prevalence of isthmocele in cases with previous cesarean section scar presented to El Shatby maternity university hospital and its association with gynecological complications.

Material and Methods:

After approval of the ethics committee of Alexandria faculty of medicine, a sample of 300 patients delivered by cesarean section since 6 months or more presented by one or more of the following symptoms: Abnormal uterine bleeding (AUB) dysmenorrhea, secondary infertility, and lower abdominal pain were selected from the gynecology clinic of El Shatby maternity university hospital. All patients were subjected to history taking, clinical, and gynecological examination. Post-menstrual 2D transvaginal ultrasonography was done. Where the niche or isthmocele was seen as triangular or dome- shaped echo-free space. Data were collected and entered to the computer using Statistical Package for the Social Science program for statistical analysis.

Results:

Niche was found in 44 cases. Most of them were symptomatic. Duration from the last (CS) was statistically significant. Symptoms were related to number of previous cesarean sections.

Conclusion:

The incidence of post-cesarean section niche in El Shatby Maternity hospital was 14.67%. Most common symptoms were AUB and dyspareunia.

Comparison of Hysteroscopic Cesarean Scar Defect Repair with 26 Fr Resectoscope and 16 Fr Mini-resectoscope: A Prospective Pilot Study

STUDY OBJECTIVE

Several studies have been published on hysteroscopic treatment of cesarean scar defect using the 26 Fr resectoscope. This study compared the effects of the 26 Fr resectoscope with those of the 16 Fr mini-resectoscope in terms of efficacy, safety profile, and peri- and postoperative complications.

DESIGN

A prospective cohort study.

SETTING

Tertiary care university hospital (S. Orsola-Malpighi, Bologna, Italy).

PATIENTS

Three hundred and nine women having symptoms and with a cesarean scar defect diagnosis were divided into 2 groups according to a temporal criterion: from March 2012 to March 2015, 155 consecutive women (control group) underwent isthmoplasty with the 26 Fr resectoscope (Karl Storz, Tuttlingen, Germany), whereas from April 2015 to March 2018, 154 consecutive women (study group) underwent isthmoplasty with the 16 Fr mini-resectoscope (Gubbini system, Tontarra Medizintechnik, Tuttlingen, Germany).

INTERVENTIONS

One hundred and fifty-five women (control group) underwent isthmoplasty with the 26 Fr resectoscope, and 154 women (study group) underwent isthmoplasty with the 16 Fr mini-resectoscope. The so-called "channel-like" 360° endocervical resection technique was applied.

MEASUREMENTS AND MAIN RESULTS

The isthmoplasty time with the 2 resectoscopes, excluding cervical dilatation, was similar (p = .25), whereas the overall surgical time was shorter in the case of the mini-resectoscope. The use of the 16 Fr mini-resectoscope was significantly associated with a reduced volume of distension medium used (p <.001) and a lower fluid absorption (p <.001). A significant increase (p = .01) in postoperative complications in the control group (9/155; 5.8%) compared with the study group (1/154; 0.7%) was also found. No significant reduction in discharge time was observed between the 2 groups (p = .13). Patient satisfaction immediately after surgery was significantly higher (p <.001) in the study group than in the control group.

CONCLUSION

Isthmoplasty with a 16 Fr mini-resectoscope seems to be as effective as isthmoplasty with a 26 Fr resectoscope in reducing postmenstrual abnormal uterine bleeding and suprapubic pelvic pain. It is associated with a significant reduction in overall surgical time owing to the non-necessity of performing cervical dilatation. The 16 Fr mini-resectoscope facilitates surgery in small anatomical spaces such as the cervical canal and reduces the complication rate linked to blind maneuvers not respecting the uterine anatomy.

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.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy of caesarean scar defect repair in improving postmenstrual bleeding and factors associated with poor effect

Caesarean scar defect (CSD) can cause postmenstrual bleeding. Defect repair is an effective technique to improve this symptom, but there are still a few patients getting little improvement. This retrospective study evaluates the efficacy of scar repair and explores the factors associated with poor effect. In total, 123 patients were involved in the final analysis. All of them complained about menstruation period >7 days due to postmenstrual bleeding. Before surgery, 87.8% of patients had a menstruation period more than 10 days and 20.3% had a period more than 15 days. After surgery, a normal menstruation period (< =7 days) was achieved in 46.3% (95%CI 37.3%-55.6%) of patients and a menstruation period lasting no more than 10 days was achieved in 74.8% (95%CI 66.2%-82.2%). Through multivariate logistic analysis, four factors were found dependently associated with poor effect (defined as menstruation period >10 days after surgery): repeated caesarean section (OR 9.75, 95%CI 2.30-41.36, 0.002) was a risk factor, while defect volume >600 mm³ (OR 0.14, 95%CI 0.03-0.56, 0.006), interval from caesarean section to symptom emerging >3 months (OR 0.25, 95%CI 0.07-0.94, 0.041) and straight or retroflexed uterus (OR 0.19, 95%CI 0.05-0.79, 0.022) were protective factors. Impact statement What is already known on this subject? Caesarean scar defect can cause postmenstrual bleeding. Defect repair can improve this symptom, but there are still a few patients getting little improvement after surgery. What do the results of this study add? Defect volume >600 mm³, interval from caesarean section to symptom emerging >3 months and straight or retroflexed uterus are protective factors of poor effect (defined as menstruation period >10 days after surgery), and repeated caesarean section is a risk factor. What are the implications of these findings for clinical practice and/or further research? These findings may help in counselling the patients and in medical decision. Further researches are needed to explore other factors associated with surgical effect and build prediction models.

Assessment of Cesarean hysterotomy scar before pregnancy and at 11-14 weeks of gestation: a prospective cohort study

OBJECTIVE

To compare the appearance and measurement of Cesarean hysterotomy scar before pregnancy and at 11-14 weeks in a subsequent pregnancy.

METHODS

This was a prospective cohort study of women aged 18-35 years who had one previous Cesarean delivery (CD) at ≥ 37 weeks. Women were examined with saline contrast sonohysterography 6-9 months after CD. A scar defect was defined as large if scar thickness was ≤ 2.5 mm. Women were followed up and those who became pregnant were examined by transvaginal ultrasound at 11-14 weeks. Scar thickness was measured and scars were classified subjectively as a scar with or without a large defect. A receiver-operating characteristics curve was constructed to determine the best cut-off value for scar thickness to define a large scar defect at the 11-14-week scan.

RESULTS

A total of 111 women with a previous CD were scanned in the non-pregnant state and at 11-14 weeks in a subsequent pregnancy. The best cut-off value for scar thickness to define a large scar defect at 11-14 weeks was 2.85 mm, which had 90% sensitivity (18/20), 97% specificity (88/91) and 95% accuracy (106/111). In the non-pregnant state, large scar defects were found in 18 (16%) women and all were confirmed at the 11-14-week scan. In addition, a large defect was found in three women at 11-14 weeks that was not identified in the non-pregnant state.

CONCLUSION

The appearance of the Cesarean hysterotomy scar was similar in the non-pregnant state and at 11-14 weeks in a subsequent pregnancy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Niches after cesarean section in a population seeking hysteroscopic sterilization

OBJECTIVE

To study the prevalence of hysteroscopically evaluated disruptions of the integrity of the uterine wall ('niches') in women with and without a previous cesarean section.

STUDY DESIGN

A prospective cohort study was performed in a teaching hospital in the Netherlands. Women seeking hysteroscopic sterilization were included. A hysteroscopic evaluation of the anterior wall of the uterus and cervix to identify the existence of disruptions (niches) was performed in a standard manner. Primary outcome was the presence of a uterine niche, defined as any visible defect, disruption, or concavity (gap) in the anterior wall. Secondary outcome was to develop a registration form of niche features for hysteroscopic evaluation.

RESULTS

In total, 713 women were included, 603 without and 110 with a previous cesarean section. In women with a previous cesarean Section 83 (75%) niches were observed using hysteroscopy. Anterior wall disruptions were not observed in women without a cesarean section. The following niche features were identified and incorporated in a registration form: polyps, cysts, myometrium defect, fibrotic tissue, (abnormal) vascular pattern, lateral branches, mucus production inside the defect, and bleeding.

CONCLUSION

In a prospective cohort study among women undergoing hysteroscopic sterilization, a uterine niche could be detected by hysteroscopy in 75% of women with a previous cesarean section.

[Interest of saline contrast sonohysterography for the diagnosis of cesarean scar defects]

OBJECTIVES

To determine the interest of saline contrast sonohysterography in the evaluation of number, size and shape of cesarean scar defects in comparison with 3D-transvaginal ultrasound examination.

METHODS

Patients who had surgical reparation of cesarean scar defect by operative hysteroscopy were included in this retrospective study. Before surgery, they all had 3D-transvaginal ultrasound examination and saline contrast sonohysterography to establish the diagnosis. Then those two exams were compared to determine which one is better for cesarean scar defect evaluation, in terms of diagnosis and severity.

RESULTS

Fourteen patients were enrolled, they underwent transvaginal ultrasound and saline contrast sonohysterography before the surgery. 3D-transvaginal ultrasound examination made the diagnosis in 50% of patients with cesarean scar defect, whereas saline contrast sonohysterography enabled to detect 86% of defects, in comparison with hysteroscopy (100%). In 29% of patients, the size and depth of the cesarean scar defect was more important with saline contrast sonohysterography and hysteroscopy than expected by 3D-transvaginal ultrasound examination. After surgical repair, symptoms improvement was found in 82% of case (pain or abnormal uterine bleeding), and fertility was restored in 67%.

CONCLUSION

Saline contrast sonohysterography is better to characterize cesarean scar defects than 3D-transvaginal ultrasound, with a higher sensibility. Moreover, it evaluates more precisely the size and shape of the defect, thus severity.

Clinical diagnosis and therapy of uterine scar defects after caesarean section in non-pregnant women

PURPOSE

Caesarean delivery (c-section) scar dehiscences may cause bleeding abnormalities, e.g. postmenstrual spotting, dysmenorrhea and abdominal pain, secondary sterility and at worst peripartum uterine rupture. The purpose of this study was firstly to identify the correlation of women's complaints after c-section with scar-related clinical symptoms. Secondly, the effects of corrective surgery on preoperatively existing complaints were analysed and assessed in the patient population of our clinic.

METHODS

We present data of a retrospective study of 13 premenopausal, non-pregnant women with symptomatic c-section scars. In 9 out of 13 patients, a microsurgical uterus reconstruction was performed by mini-laparotomy. The postoperative changes of scar-associated symptoms were assessed by a questionnaire as earliest as 4 months after surgery (N = 5).

RESULTS

The c-section scar was visualised by transvaginal sonography in 12 out of 13 women by a typical U- or V-shaped hypoechoic or anechoic fluid accumulation in the region of former uterotomy and in all 13 patients by hysteroscopy. Bleeding disorders were often accompanied by dysmenorrhea/abdominal pain (38.5%, N = 5) and secondary sterility (46.2%, N = 6). Blood residues in the scar pouch and bleeding disorders/postmenstrual spotting were found in 30.8% of patients (N = 4) and combined with secondary sterility in 38.5% of patients (N = 5). Reconstructive surgeries resulted in discontinuation of bleeding disorders in all women and a pregnancy in three out of five patients (60%) with secondary sterility.

CONCLUSION

Clinical symptoms, e.g. "bleeding disorders" like postmenstrual spotting, "pain/dysmenorrhea" and "secondary sterility" could be specific indicators for the diagnosis of uterine dehiscence after c-section. Scar dehiscences can be diagnosed by obtaining the patients medical history and asking for typical symptoms followed by vaginal sonography and diagnostic hysteroscopy. If a c-section scar defect is confirmed, microsurgical uterus reconstruction can stop postmenstrual spotting, reduce abdominal pain/dysmenorrhea and improve fertility.

Prevalence, potential risk factors for development and symptoms related to the presence of uterine niches following Cesarean section: systematic review

OBJECTIVE

To review systematically the medical literature reporting on the prevalence of a niche at the site of a Cesarean section (CS) scar using various diagnostic methods, on potential risk factors for the development of a niche and on niche-related gynecological symptoms in non-pregnant women.

METHODS

The PubMed and EMBASE databases were searched. All types of clinical study reporting on the prevalence, risk factors and/or symptoms of a niche in non-pregnant women with a history of CS were included, apart from case reports and case series.

RESULTS

Twenty-one papers were selected for inclusion in the review. A wide range in the prevalence of a niche was found. Using contrast-enhanced sonohysterography in a random population of women with a history of CS, the prevalence was found to vary between 56% and 84%. Nine studies reported on risk factors and each study evaluated different factors, which made it difficult to compare studies. Risk factors could be classified into four categories: those related to closure technique, to development of the lower uterine segment or location of the incision or to wound healing, and miscellaneous factors. Probable risk factors are single-layer myometrium closure, multiple CSs and uterine retroflexion. Six out of eight studies that evaluated niche-related symptoms described an association between the presence of a niche and postmenstrual spotting.

CONCLUSIONS

The reported prevalence of a niche in non-pregnant women varies depending on the method of detection, the criteria used to define a niche and the study population. Potential risk factors can be categorized into four main categories, which may be useful for future research and meta-analyses. The predominant symptom associated with a niche is postmenstrual spotting.

Long-term complications of caesarean section. The niche in the scar: a prospective cohort study on niche prevalence and its relation to abnormal uterine bleeding

OBJECTIVE

To study the prevalence of niches in the caesarean scar in a random population, and the relationship with postmenstrual spotting and urinary incontinence.

DESIGN

A prospective cohort study.

SETTING

A teaching hospital in the Netherlands.

POPULATION

Non-pregnant women delivered by caesarean section.

METHODS

Transvaginal ultrasound (TVU) and gel instillation sonohysterography (GIS) were performed 6-12 weeks after caesarean section. Women were followed by questionnaire and menstruation score chart at 6-12 weeks, 6 months, and 12 months after caesarean section.

MAIN OUTCOME MEASURES

Prevalence of a niche 6-12 weeks after caesarean section, using TVU and GIS.

SECONDARY OUTCOMES

relation to postmenstrual spotting and urinary incontinence 6 and 12 months after caesarean section; and niche characteristics, evaluated by TVU and GIS.

RESULTS

Two hundred and sixty-three women were included. Niche prevalence was 49.6% on evaluation with TVU and 64.5% with GIS. Women with a niche measured by GIS reported more postmenstrual spotting than women without a niche (OR 5.48, 95% CI 1.14-26.48). Women with residual myometrium at the site of the uterine scar measuring <50% of the adjacent myometrial thickness had postmenstrual spotting more often than women with a residual myometrial thickness of >50% of the adjacent myometrial thickness (OR 6.13, 95% CI 1.74-21.63). Urinary incontinence was not related to the presence of a niche.

CONCLUSIONS

A niche is present in 64.5% of women 6-12 weeks after caesarean section, when examined by GIS. Postmenstrual spotting is more prevalent in women with a niche and in women with a residual myometrial thickness of <50% of the adjacent myometrium.

[Uterine ishtmique transmural hernia: results of its repair on symptoms and fertility]

OBJECTIVE

To study the effect of the surgical repair (isthmorraphy) of the large scar dehiscence after cesarean on symptoms and fertility for women who desire pregnancy.

PATIENTS AND METHODS

In this retrospective study, 14 symptomatic patients, who desire a new pregnancy underwent a surgical repair by laparotomy, laparoscopic or vaginal technique. Five women experienced failure of Assistance Reproductive Technique (IVF or ICSI) for idiopathic secondary infertility. The dehiscent scars were evaluated by ultrasound, hysterography, hysteroscopy and magnetic resonance imaging.

OUTCOME

Symptoms improvement was found in 92% of case. Ten pregnancy (71%) was obtained after surgical repair, 6 spontaneous and 4 after Assistance Reproductive Technique. Among the 5 women initially followed in the reproductive unit, 4 became pregnant, 3 after IVF or ICSI and 1 spontaneous. No operative complication occurred. The subsequent pregnancy was unremarkable with no uterine rupture.

DISCUSSION

Large scar defect after cesarean can take shape of a complete absent of the anterior wall of the uterus. No incident has been proved in this condition. There is a lack of data concerning these isthmocele. The experience of hysteroscopic repair cannot be applied to these real large diverticule of the scar cesarean. The results of this study suggest a link between the isthmocele and reversible symptoms after surgery. The first results concerning the subsequent fertility after surgical repair seem interesting

CONCLUSION

When a large scare defect (isthmocele) is found in symptomatic woman (pelvic pain, bleeding uterine, infertility), a surgical repair can be proposed, especially for woman who desire a new pregnancy.

Predicting successful vaginal birth after Cesarean section using a model based on Cesarean scar features examined by transvaginal sonography

OBJECTIVE

To develop a model to predict the success of a trial of vaginal birth after Cesarean section (VBAC) based on sonographic measurements of Cesarean section (CS) scar features, demographic variables and previous obstetric history.

METHODS

We used transvaginal sonography (TVS) to examine the CS scar of 320 consecutive pregnant women. TVS was carried out at 11-13, 19-21 and 34-36 weeks' gestation and prospective measurements of the scar were recorded at each visit according to a defined protocol. A logistic regression model to predict success of VBAC was developed for those patients with a visible scar on ultrasound and only one previous CS. The model was evaluated using bootstrap validation.

RESULTS

There were 131 women with one previous CS and a visible scar, of whom 10 underwent CS prior to labor and were excluded from analysis. Successful VBAC was achieved in 74/121 (61%) of the remaining cases. The prediction model developed was based on patient age, previous history of VBAC, residual myometrial thickness (RMT) and the change in RMT from the first to the second trimester (ΔRMT). The internally validated area under the receiver-operating characteristics curve was 0.62 when measurements of RMT and ΔRMT were excluded, but 0.94 when scar information was incorporated into the model.

CONCLUSION

Ultrasound measurements of CS scar, namely RMT and the change in RMT from the first to the second trimester of pregnancy, when incorporated into a mathematical model, can predict accurately a successful trial of labor in patients with one previous CS.

Changes in Cesarean section scar dimensions during pregnancy: a prospective longitudinal study

OBJECTIVES

To describe changes in Cesarean section (CS) scars longitudinally throughout pregnancy, and to relate initial scar measurements, demographic variables and obstetric variables to subsequent changes in scar features and to final pregnancy outcome.

METHODS

In this prospective observational study we used transvaginal sonography (TVS) to examine the CS scar of 320 consecutive pregnant women at 11-13, 19-21 and 32-34 weeks' gestation. For scars visible on TVS, the hypoechoic part was measured in three dimensions and the residual myometrial thickness (RMT) was also measured. Analyses were carried out using one-way repeated measures ANOVA and mixed modeling. The incidence of subsequent scar rupture was recorded.

RESULTS

The CS scar was visible in 284/320 cases (89%). Concerning length and depth of the hypoechoic part of the scar and RMT, the larger the initial scar measurement, the larger the decrease observed during pregnancy. For the hypoechoic part of the scar, the width increased on average by 1.8 mm per trimester, while the depth and length decreased by 1.8 and 1.9 mm, respectively (false discovery rate P < 0.0001). Mean RMT in the first trimester was 5.2 mm and on average decreased by 1.1 mm per trimester. Two cases (0.62%) of uterine scar rupture were confirmed following a trial of vaginal delivery; these had a mean RMT of 0.5 mm at second scan and an average decrease of 2.6 mm over the course of pregnancy.

CONCLUSION

This study establishes reference data and confirms that the dimensions of CS scars change throughout pregnancy. Scar rupture was associated with a smaller RMT and greater decrease in RMT during pregnancy. There is the potential to test absolute values and observed changes in CS scar measurements as predictors of uterine scar rupture and outcome in trials of vaginal birth after Cesarean section.

Sonographic assessment of post-cesarean section uterine scar in pregnant women

PURPOSE

To detect location of uterine cesarean scar in relation to cervix in pregnancies with previous cesarean section (CS) and to compare location between elective and emergent previous CS.

STUDY DESIGN

Prospective study, 91 pregnant women with previous low transverse CS. Two groups: previous elective [36 (39.6%)] and emergent CS [55 (60.4%)]. Transvaginal ultrasound was performed between 14 and 16 weeks. Cervical length (CL) and distance between external oss to hypoechogenic line (EO-HL distance), which describes location of cesarean scar, were measured. Surgical incision was considered cervical when EO-HL distance was smaller than CL.

RESULTS

Mean CL and EO-HL distance: 45.4 + 7. 0 and 39.0 + 9.4 mm, respectively for all patients. No significant differences were observed in CL (45.9 + 6.2 vs. 45.1 + 8.5 mm; p = not significant [NS]) and EO-HL distance (40.7 + 9.7 vs. 37.9 + 9.1 mm; p = NS) between both groups. Sixty-four cases (70.3%) had cervical scar, eight (8.8%) at the level of the internal oss and 19 (20.9) in the lower uterine segment. No significant difference was observed between both groups regarding location of scar (cervix -72 vs. 67% emergent vs. elective, respectively; p = NS).

CONCLUSION

CS incisions are mostly performed in cervix, in elective as well as in emergent operations.

Standardized approach for imaging and measuring Cesarean section scars using ultrasonography

Incomplete healing of the scar is a recognized sequel of Cesarean section (CS) and may be associated with complications in later pregnancies. These complications can include scar pregnancy, a morbidly adherent placenta, scar dehiscence or rupture. To date there is uncertainty relating to the factors that lead to poor scar healing and how to recognize it. In recent years, there has been an increase in studies using ultrasound that describe scars as deficient, or poorly, incompletely or inadequately healed with few data to associate the morphology of the scar with the functional integrity of the lower segment of the uterus. There have been multiple attempts to describe CS scars using ultrasonography. Different terminology, methods and results have been reported, yet there is still no consensus regarding the prevalence, clinical significance or most appropriate method to describe the appearances of these scars. Developing a test that can predict the likelihood of women having problems associated with a CS scar is becoming increasingly important. On the other hand, understanding whether the ultrasound appearances of the scar can tell us anything about its integrity is not well supported by the research evidence. In this article we present an overview of ultrasound-based definitions and methods used to describe CS scars. We also present information relating to the performance of alternative techniques used to evaluate CS scars. Having examined the current evidence we suggest a standardized approach to describe CS scars using ultrasound so that future studies can be meaningfully compared.

A retrospective case-control study comparing hysteroscopic resection versus hormonal modulation in treating menstrual disorders due to isthmocele

In a retrospective case-control study, we compared the effectiveness of hysteroscopic correction and hormonal treatment to improve symptoms [postmestrual abnormal uterine bleeding (PAUB), pelvic pain localized in suprapubic site] associated with isthmocele. Women (n = 39; mean age ± SD, 35 ± 4.1 years) were subdivided in Group A [patients (n = 19) subjected to hysteroscopic surgery (isthmoplasty)] and, Group B [women (n = 20) undergoing hormonal treatment consisting of one oral tablet containing 0.075  mg of Gestodene and 0.030 mg of Ethynylestradiol for 21 days, followed by 7 days of suspension]. Resolution and/or improvement of menstrual disorders; patients degree of satisfaction with the treatment were measured 3 months later, by office hysteroscopy (Grop A) or phone call. PAUB and pelvic pain resolution was achieved in all patients: Group A had significant lower numbers of days of menstrual bleeding (P < 0.001), prevalence of pelvic pain in the suprapubic area (P = 0.04) and, higher degree of satisfaction (P < 0.001) compared to Group B. In conclusion, resectoscopic surgery is a valid way to treat patients with symptoms of prolonged postmenstrual uterine bleeding caused by isthmocele. Data from this study also indicate that resectoscopy may be the first choice because it is minimally invasive and yields good therapeutic results.

Ultrasound evaluation of the Cesarean scar: relation between a niche and postmenstrual spotting

OBJECTIVE

To evaluate the relationship between a niche and abnormal uterine bleeding, and to develop a sonographic classification of niches and evaluate its relationship to abnormal uterine bleeding.

METHODS

An observational prospective cohort study was performed between October 2007 and May 2009. All women who had a Cesarean section performed in our hospital were asked to participate. Two hundred and twenty-five women were included and examined with both transvaginal sonography (TVS) and gel instillation sonohysterography (GIS) 6-12 months after the Cesarean section. In case of a niche, the depth, volume and residual myometrium were measured, and the shape was assessed according to a specified classification. A questionnaire and pictorial blood loss assessment chart were filled in.

RESULTS

The prevalence of a niche on evaluation with TVS and GIS was 24.0% and 56.0%, respectively. A niche was considered to be present if the depth was at least 1 mm visualized with GIS. Postmenstrual spotting was reported by 33.6% of women with a niche and 15.2% of women without a niche (P = 0.002). The niche volume was significantly different between women with and without postmenstrual spotting (P = 0.02). Most niches had a semicircular (50.4%) or triangular shape (31.6%). No significant relationship was identified between the shape of the niche and postmenstrual spotting (P = 0.19).

CONCLUSIONS

A niche is present in 56.0% of women with a history of Cesarean section when examined by GIS and is associated with postmenstrual spotting. Semicircular and triangular niches are most common, but the shape is not related to postmenstrual spotting.

Cesarean section scar defects: agreement between transvaginal sonographic findings with and without saline contrast enhancement

OBJECTIVES

To determine the agreement between transvaginal ultrasound examinations performed before and at saline contrast sonohysterography (SCSH) with regard to number, size and shape of Cesarean section (CS) scar defects.

METHODS

In all, 108 women underwent transvaginal ultrasound examination with SCSH at least 6 months after CS: 68 had undergone one CS, 32 two CSs and eight women had undergone at least three CSs. The ultrasound examiner was blinded to the number of CSs and to the obstetric history. The number and shape of CS scar defects were determined subjectively, and any scar defect was estimated subjectively to be large or not large. Measurements of the scar defects were also taken. Results obtained before and at SCSH were compared.

RESULTS

Most scar defects were triangular in shape. The shape did not change at SCSH, but the ultrasound examiner found it easier to delineate the borders of the scar defects at SCSH than at unenhanced ultrasound examination. More scar defects were seen and more scar defects were classified as large at SCSH than before: among the 100 women who had undergone one or two CSs, 16 additional women had large defects at SCSH, whereas no woman with a large defect before SCSH had no defect or only a small defect at SCSH. The length and height of the defects were larger at SCSH than before: mean difference 2 mm and 1 mm in women who had undergone one CS, and mean difference 4 mm and 2 mm in the lowest-positioned scar in women who had undergone two CSs.

CONCLUSIONS

In non-pregnant women CS scars were better evaluated at SCSH than at unenhanced ultrasound examination, because the demarcations of scar defects were more clearly delineated at SCSH than before. More defects were detected and more defects were classified as large at SCSH.

High prevalence of defects in Cesarean section scars at transvaginal ultrasound examination

OBJECTIVES

To determine the ability to correctly identify Cesarean section scars, to estimate the prevalence of defective scars, and to determine the size and location of scar defects by transvaginal ultrasound imaging.

METHODS

Two hundred and eighty-seven women underwent transvaginal ultrasound examination 6-9 months after delivery: 108 had undergone one Cesarean section, 43 had had two Cesarean sections, 11 had undergone at least three Cesarean sections, and 125 were primiparae who had delivered vaginally. The ultrasound examiner was blinded to the obstetric history until all scans had been evaluated.

RESULTS

None of the 125 vaginally delivered women had a visible scar in the uterus, whereas all women who had undergone Cesarean section had at least one visible scar. Median myometrial thickness at the level of the isthmus was 11.6 mm in women who had only been delivered vaginally, and 8.3 mm, 6.7 mm and 4.7 mm in women who had undergone one, two and at least three Cesarean sections, respectively (P < 0.001). Scar defects were seen in 61% (66/108), 81% (35/43) and 100% (11/11) of the women who had undergone one, two and at least three Cesarean sections (P = 0.002); at least one defect was classified as large by the ultrasound examiner in 14% (15/108), 23% (10/43) and 45% (5/11) (P = 0.027), and at least one total defect was seen in 6% (7/108), 7% (3/43) and 18% (2/11) (P = 0.336). In women who had undergone one Cesarean section, the median distance between an intact scar and the internal cervical os was 4.6 (range, 0-19) mm, and that between a deficient scar and the internal cervical os was 0 (range, 0-26) mm (P < 0.001).

CONCLUSIONS

Cesarean section scars can be detected reliably by ultrasound imaging. Myometrial thickness at the level of the isthmus uteri decreases with the number of Cesarean sections and the frequency of large scar defects increases. Scars with defects are located lower in the uterus than intact scars.