Evaluation of uterine niche by three-dimensional sonohysterography and volumetric quantification: techniques and scoring classification system

Isthmocele and Infertility

Isthmocele is a gynecological condition characterized by a disruption in the uterine scar, often associated with prior cesarean sections. This anatomical anomaly can be attributed to inadequate or insufficient healing of the uterine wall following a cesarean incision. It appears that isthmocele may impact a woman's quality of life as well as her reproductive capacity. The incidence of isthmocele can range from 20% to 70% in women who have undergone a cesarean section. This review aims to sum up the current knowledge about the effect of isthmocele on fertility and the possible therapeutic strategies to achieve pregnancy. However, currently, there is not sufficiently robust evidence to indicate the need for surgical correction in all asymptomatic patients seeking fertility. In cases where surgical correction of isthmocele is deemed necessary, it is advisable to evaluate residual myometrial thickness (RMT). For patients with RMT >2.5-3 mm, hysteroscopy appears to be the technique of choice. In cases where the residual tissue is lower, recourse to laparotomic, laparoscopic, or vaginal approaches is warranted.

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.

Kasr Alainy simplified uterine preserving surgery for conservative management of placenta accreta spectrum (PAS): A modified surgical approach

OBJECTIVE

The incidence of placenta accreta spectrum (PAS) is rising rapidly due to the global surge in Caesarean delivery. It is associated with significant maternal morbidity and mortality. It is usually managed with Caesarean hysterectomy. However, uterine preserving surgeries can have advantages over Caesarean hysterectomy and intentional placental retention techniques.

STUDY DESIGN

We present a modified technique of uterine preserving surgery that uses a safe approach for placental bed surgical devascularization. This is followed by resection of the invaded uterine segment and uterine wall reconstruction.

RESULTS

The technique was used in the management of 20 patients with antenatally suspected PAS that were confirmed at laparotomy. It was successful in preserving the uterus in 18/20 (90 %) women. The mean intraoperative blood loss in was 1305 CC (SD: +361.6) with a mean operative time of 123 min (SD: ±38.7). There was only one urinary bladder injury and no other maternal morbidity.

CONCLUSION

Our surgical technique is safe and may be useful for conservative surgical management of PAS, particularly in low- and middle-income countries, where access to complex resources, such as interventional radiology, is limited.

Increased amplitude of subendometrial contractions identified by ultrasound speckle tracking in women with a caesarean scar defect

RESEARCH QUESTION

What is the effect of a caesarean scar defect on subendometrial contractions?

DESIGN

Prospective cohort study in a Dutch medical centre including women with a niche in the uterine caesarean section scar. Data were compared with controls without a caesarean section scar. All women underwent a 5-min recording by transvaginal ultrasound at four phases in the menstrual cycle: during menses; late follicular; early luteal; or late luteal phase. Uterine motion analysis was evaluated by dedicated speckle tracking using two-dimensional optical flow.

MAIN OUTCOME

amplitude of the subendometrial contractions.

RESULTS

Thirty-one women with a niche in the uterine scar and 11 controls, matched for menstrual cycle phase, were included. The amplitude of the subendometrial contractions was significantly higher in women with a niche compared with controls during all phases of the menstrual cycle (menses P < 0.001; late follicular P < 0.001; early luteal P = 0.028; late luteal P = 0.003). Velocity was lower in women with a niche during late follicular phase only (P = 0.012). A positive correlation between niche sizes (depth, length) and amplitude of subendometrial contractions was found.

CONCLUSION

Subendometrial contractions were affected in women with a niche in the caesarean section scar compared with women who had not undergone a previous caesarean section. Contraction amplitude was higher and independent of the menstrual phase. These findings may cause postmenstrual spotting, dysmenorrhoea and lower implantation rates in women with a niche. Future studies should investigate this association and the underlying pathways.

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.

Position and integrity of uterine scar are determined by degree of cervical dilatation at time of Cesarean section

OBJECTIVE

Abnormal placental invasion is more common after an elective Cesarean delivery, suggesting that prelabor Cesarean section (CS) increases the likelihood of the CS scar being above the internal cervical os and predisposing to a scar pregnancy in the future. The aim of this study was to assess the location and integrity of the CS scar in postpartum women delivered by CS at different stages of labor.

METHODS

This was a prospective cohort study of women at term who underwent a CS for the first time. In all women, cervical dilatation was determined by digital examination at the time of the CS. All patients had a transvaginal ultrasound examination to assess the location of the CS scar in relation to the internal cervical os, as well as the presence of a scar niche.

RESULTS

A total of 407 pregnant women were recruited into the study: 103 with cervical dilatation ≤ 2 cm, 261 with cervical dilatation 3-7 cm and 43 with cervical dilatation ≥ 8 cm at the time of the CS. A statistically significant correlation was observed between cervical dilatation at the time of the CS and the position of the CS scar. The scar was positioned in the uterus above the internal cervical os in 97.1% (100/103) of women delivered at a cervical dilatation of 0-2 cm, whereas the scar was located at or below the internal cervical os in 97.7% (42/43) of cases delivered at a cervical dilatation of 8-10 cm (P < 0.001). A uterine-scar defect (niche) was observed in 38.1% (64/168) of women with the scar located above, compared with 18.0% (43/239) of those with the scar situated at or below, the internal cervical os (P < 0.001).

CONCLUSIONS

Prelabor and early-labor Cesarean delivery are associated with an increased prevalence of a scar in the uterine cavity as well as a scar niche. CS in late labor is associated with the uterine scar being situated in the endocervical canal and with a lower incidence of a niche. The position and integrity of the CS scar after prelabor and early-labor Cesarean delivery explain the predisposition to abnormal placental invasion in subsequent pregnancy. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

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.

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.