2D saline sonohysterography versus 3D saline sonohysterography versus hysteroscopy in detecting the cesarean scar niche in women with previous cesarean section or more: A Prospective study at Minia Maternity and Children University Hospital

Introduction

A uterine diverticulum, pouch, sacculation, isthmocele, cesarean scar defect, or cesarean scar dehiscence is another name for a niche. According to Gubbini et al., (2008) ⁽¹²⁾, this condition was initially identified and is characterized by a pouch-like abnormality of the anterior uterine isthmus at the site of a previous cesarean section.

Any dimpling of the uterus that is 2 mm or larger at the location of the cesarean scar and can be seen by ultrasonography is considered a niche ⁽¹³⁾.

According to Gubbini et al., (2008)⁽¹³⁾, gyneco-logic symptoms such as infertility, pelvic pain, abnormal uterine bleeding (AUB) caused by retained menstrual blood passing intermittently through the cesarean scar defect (CSD), and caesarean-induced isthmocele might develop. and⁽¹⁴⁾ Stewart et al., 1975 ⁽¹⁵⁾ was the first publication to record a scar defect; they suggested that pelvic arteriography or preoperative historiography could aid in identification and that removing the lower segment scar could preserve the uterus.

It is possible that the 19% to 84% global prevalence of post-cesarean scar niche, as a percentage of all cesarean sections, is under appreciated due to asymptomatic patients and a lack of clinical knowledge⁽⁷⁾. Compared to transvaginal ultrasonography, sonohystero-graphy (SHG) detected isthmoceles in a greater percentage of patients (56%–78%)⁽¹⁷⁾.

Globally, caesarean sections are becoming more common, which increases the risk of a number of obstetric problems, including placenta accreta, scar dehiscence, uterine rupture (particularly during the first post-caesarean section trial), and ectopic scar pregnancy as a result of improper healing.

According to a 2017 report by Robson et al.,, the World Health Organization expressed concern over the high number of caesarean sections and suggested limiting surgical intervention to no more than 15% of cases.

Regardless, among developed countries, the rate of caesarean sections increased by 50% between 1996 and 2007, with Brazil and other countries reporting rates as high as 45% ⁽¹⁸⁾.

The most current Egypt Demographic and Health Survey (EDHS) recorded a cesarean delivery rate of 52%, indicating that the practice may be overused or utilized for unsuitable purposes, given the dramatic increase in the prevalence of CS over the past decade. ⁽¹⁹⁾ published

While over 26% of babies are born this way in the UK, in other countries it's much higher: when focusing solely on institutional births in Egypt, the proportion rises to 63% and in the Dominican Republic, over 58% ⁽²⁰⁾.

Many women who have uterine niche may not experience any symptoms at all, and it may take multiple visits to the doctor before the correct diagnosis is made.

Because the niche stores blood during menstruation, the most common complaint is irregular menstruation that lasts anywhere from two days to twelve days ⁽²¹⁾.

Several sources have pointed to sperm motility and implantation issues in the uterine niche as reasons for infertility. Many gynecologic conditions can produce generalized pain and dysmenorrhea ⁽²²⁾.

Contractions induced by the uterus's continual efforts to empty the contents of the isthmocele may be associated with the uterine niche and pain, but the exact nature of this interaction is unclear. According to Wang et al.,, there is a strong correlation between dysmenorrhea, the size of the defect, and the frequency of irregular bleeding in infertile cases.⁽²³⁾

Impaired fertility may result from isthmocele blood's potential effects on cervical mucus and sperm quality, obstruction of sperm transit, and difficulty implanting embryos. Isthmocele repair is associated with high rates of restoring fertility, according to multiple studies that investigated the reproductive results after therapy. ⁽²³⁾

Aim of the study

To evaluate the prevalence of post-caesarean scar niche and to compare the accuracy of two dimensional saline Sono hysterography (2D SHG) versus three dimensional saline Sono hysterography (3D SHG) in evaluating the uterine scar depth (D), base width (BW) and the residual myometrial thickness (RMT) in women complaining of abnormal uterine bleeding, offensive, vaginal discharge, pelvic pain & secondary infertilitywith previous one caesarean section or more  in comparison with hysteroscopy which is the gold standard in diagnosis post-caesarean scar niche .

Patients and Methods

This prospective observational study was conducted on women with previous cesarean section or more at the department of Obstetrics and Gynecology at Minia Maternity and Children University Hospital through the period from March 2021 to March 2023.

Inclusion Criteria:

• 18 to 40 years old aged non-pregnant females who had previous cesarean section or more with abnormal uterine bleeding, offensive vaginal discharge, pelvic pain and secondary infertility
• Patients were assessed post menstrual.

Exclusion Criteria:

• Women with no previous sections
• Patients with any focal lesion and any cervical pathology as tumors such as fibroids, adenomyosis, or endometrial hyperplasia
• Patients who had associated pathology in their ovaries
• Postmenopausal women
• Known anomaly of uterus
• History of previous myomectomy.

Methods

Patients were subjected to:

Complete history taking:

• Personal history including: Name, Age, marital state, address
• Menstrual history: including age of Menarche, menstrual disturbance, dysmenorrhea, related symptoms.
• History Parity
• History of infertility
• Present history: of chronic diseases and medication.
• Past history of HTN, DM.
• Family history of similar condition or diabetes.
• History of allergy to any medication.  
• Gestational age of fetus at time of labor
• Birth weight
• Patient was in labour or not
• Augmentation of labour with oxytocin
• History of medical of disorders as:

• Diabetes Mellitus
• Pregnancy induced hypertension/ pre eclampsia

• History of postpartum hemorrhage
• History of sepsis, endometritis & wound infection
• History of any previous operations especially abdominal ones
• Any detailed history about cesarean section in the form of (type Of cesarean section, time consumed during cesarean section, its indication, clorure of myometrium single layer or double layer, any complication during cesarean section as angle extension or bladder injury and postpartum complication as hemorrhage or sepsis)

Examination:

1. General examination:

• Vital signs (Blood pressure, Temperature, Heart rate, Respiratory rate)
• level of consciousness and O2 saturation
• Signs of (Pallor, Cyanosis, Jaundice, and Lymph node enlargement).

Results

• Results of the current study were expressed on the following tables and figures

• Discussion

  The percentage of births that require a caesarean section (25 percent in Europe at present) has increased from 6.7% to 19.1% globally in the last several decades ⁽¹⁾.

   

  Recent data from the Egypt Demographic and Health Survey (EDHS) shows that 52% of births in Egypt occur via cesarean section, which suggests that this method of childbirth may be used too frequently or for inappropriate reasons^(2;3).

   

  A variety of terminology are used to characterize the anomaly that is discovered by ultrasonography after a cesarean section, including scar defect, niche, isthmocele, uterine pouch, and diverticula. Abnormal uterine bleeding (AUB) is one of several symptoms associated with niches. In 30% of women with niches, this manifests as prolonged menstruation and postmenstrual spotting ⁽⁴⁾.

   

  Possible causes of infertility after caesarean section have been suggested in the literature, including uterine illness, intra-abdominal adhesions, and women's reproductive choices. Although some niches do cause symptoms, there is a lack of direct evidence linking subfertility to niches in uterine scars, hence further study is needed to establish this link ⁽⁵⁾.

   

  Ultrasound allows for a non-invasive examination of the uterus and any potential scars. The use of ultrasonography (US) to evaluate uterine scars during pregnancy is extensive, but its utility in evaluating uterine scars when the patient is not pregnant is restricted. Anechoic contrast media is infused into the uterine cavity during a saline infusion sonohysterography (SIS) examination to enhance the transvaginal ultrasound (7US) of the uterus. As a result, SIS brings together the benefits of both US and hysterosalpingography ^{(6) & (16)}.

   

  Recent advances in SIS have made it easier to evaluate the uterine cavity, including measuring the remaining myometrium thickness, the myometrium surrounding the scar, the depth of the filling defect in the scar (niche), and intrauterine adhesions connected to the scar ⁽⁸⁾.

   

  Owing to its safety and minimally invasive nature, office hysteroscopy (OH) is considered the "gold standard" for diagnosing intrauterine abnormalities. It has also been shown to be an effective tool for directly observing uterine scars and intrauterine adhesions ⁽⁹⁾. 

   

  One method that has helped increase the use of office hysteroscopy and all its benefits is the vaginal speculum approach. This method has reduced patient pain and operator experience because it eliminates the need for a vaginal speculum or cervical instrumentation to grasp and steady the cervix ^{(10); (11)}.

   

  Thus, the purpose of this study was to determine how common post-cesarean scar niches are and to compare the accuracy of two-dimensional saline sonohysterography (2D SHG) and three-dimensional saline sonohysterography (3D SHG) in assessing the depth of the uterine scar (D), the width of the base (BW), and the residual myometrial thickness (RMT) in women who have experienced secondary infertility and have had one or more cesarean sections. Additionally, we want to assess hysteroscopy's function in the post-cesarean scar niche diagnostic process.

   

  From March 2021 through March 2023, researchers from Minia Maternity and Children University Hospital's Department of Obstetrics and Gynecology carried out a prospective observational study.

   

  Women who had two or more caesarean sections in the past and were experiencing infertile symptoms were included in the study.

   

  The age of the participants in the study varied from 19 to 37 years, with an average of 28.49 years. The largest age group was those between 30 and 39 years (47.3%), followed by those between 20 and 29 years (46.7%), and those younger than 20 years (6.6%). Their average body mass index (BMI) was 26.57 ±3.74, their average height was 167.49±7.21 cm, and their average weight was 75.68 ±13.96 kg. Before the start of labor pains, 62% of women planned to have an elective cesarean section. An urgent cesarean section was necessary for 38% of the women, with 12.7% undergoing induction and

  10.7% undergoing augmentation; this resulted in a cervical dilatation of 0-6 cm at the cesarean section, with a mean value of 2.17 cm, and other women experienced difficulty during pregnancy or during giving birth.  Fever developed after surgery in 20.7% of patients, and approximately one-third suffered postoperative nausea and vomiting (PROM).