The research conducted by Zhang et al. [Citation1] is very topical and important at the present time because of the increasing frequency of cesarean sections observed over the last decades in developed countries. Therefore, complications of this procedure have become more common [Citation2]. The previous cesarean scar defect (PCSD), isthmocele, or niche is any indentation resulting in myometrial discontinuity at the site of the cesarean scar that communicates with the uterine or cervical cavity.
According to Osser et al., the reported prevalence of isthmocele has varied considerably, between 6.9 and 69% depending on the study population and the method used for evaluation [Citation3].
It can be asymptomatic or associated with several symptoms (abnormal uterine bleeding, dysmenorrhea, dyspareunia, pelvic pain, infertility).
A patient may present with abnormal uterine bleeding characterized as postmenstrual bleeding because of blood accumulating in the outpouching of the isthmocele and lack of coordinated muscle contractions, leading to continued accumulation of blood and menstrual debris. Postmenstrual spotting has been associated with isthmocele, and it has been found to correlate with the size of the defect [Citation4]. A study by Van der Voet et al. reported a prevalence of postmenstrual spotting of 28.9% among women with isthmocele compared to 6.9% among women without the defect [Citation5]. In the isthmocele group of a Finnish study involving 401 women, the prevalence of postmenstrual spotting was 20.0% compared to 8.3% in women without isthmocele (OR 2.75 [95% CI 1.39–5.44]; p = 0.004) [Citation6].
Transvaginal ultrasound, sonohysterography, and hysteroscopy can be used to diagnose the niche. Transvaginal ultrasound is the first choice among these diagnostic methods, but we can reach higher specificity and sensitivity with the use of sonohysterography, which enhances the ability to delineate the defect and enables detection of a subtle isthmocele. The remaining myometrial thickness can also be measured by SAS [Citation7]. According to this data, the author’s research group used transvaginal ultrasound with 15–20 ml saline-assisted sonohysterography to confirm the niche and to measure the width, length, and depth of the defect as well as the thickness of the residual myometrium covering the diverticulum.
The treatment method of the niche is surgical and can be performed with hysteroscopy, laparoscopy, or open surgery via the vaginal route. The proper choice of surgical treatment method depends on the myometrium layer covering the niche, the personal skills of the available surgeons, and the facilities [Citation8]. In this study patients were divided into two groups: laparoscopic repair and hysteroscopic resection based on residual myometrial thickness (RMT). For those that had RMT of <3 mm, hysteroscopy was recommended, and for patients with RMT above 3 mm, laparoscopy was recommended.
Zhang et al. analyzed 62 cases retrospectively. They found operative time was significantly shorter (30.9 ± 5.0 vs 71.0 ± 7.0 min) for hysteroscopic PCSD resection compared to laparoscopic PCSD repair. The amount of blood loss was significantly less (10.4 ± 4.6 vs 36.6 ± 4.0 ml; p < 0.001) and the postoperative hospital stay (2.1 ± 0.4 vs 4.6 ± 1.0; p < 0.001) was significantly shorter than in patients who underwent laparoscopic repair of PCSD. The effectiveness rate was 91.4% for hysteroscopic PCSD resection and 96.3% for laparoscopic PCSD repair [Citation1].
Results of the study have shown promising outcomes for the use of both hysteroscopy and laparoscopy in the repair of symptomatic PCSD. Proper diagnostics and preoperative assessment are essential for the convenient choice of method and satisfactory results of the surgical therapy.
Disclosure statement
No potential conflict of interest was reported by the author.
References
- Zhang N-N, Wang G-W, Yang Q. Endoscopic treatment of previous cesarean scar defect in women with postmenstrual bleeding: a retrospective cohort study. J Investig Surg. 2021;34(10):1147–1155. doi: https://doi.org/10.1080/08941939.2020.1766161.
- Vitale SG, Ludwin A, Vilos GA, et al. From hysteroscopy to laparoendoscopic surgery: what is the best surgical approach for symptomatic isthmocele? A systematic review and meta-analysis. Arch Gynecol Obstet. 2020;301(1):33–52.
- Osser OV, Jokubkiene L, Valentin L. High prevalence of defects in Cesarean section scars at transvaginal ultrasound examination. Ultrasound Obstet Gynecol. 2009;34(1):90–97.
- Bij de Vaate AJM, Brolmann HAM, van der Voet LF, et al. Ultrasound evaluation of the Cesarean scar: relation between a niche and postmenstrual spotting. Ultrasound Obstet Gynecol. 2011;37 (1):93–99.
- van der Voet LF, Bij de Vaate AM, Veersema S, et al. 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. BJOG Int J Obstet Gynaecol. 2014;121(2):236–244.
- Antila RM, Mäenpää JU, Huhtala HS, et al. Association of cesarean scar defect with abnormal uterine bleeding: the results of a prospective study. Eur J Obstet Gynecol Reprod Biol. 2020;244:134–140.
- Hayakawa H, Itakura A, Mitsui T, et al. Methods for myometrium closure and other factors impacting effects on cesarean section scars of the uterine segment detected by the ultrasonography. Acta Obstet Gynecol Scand. 2006;85(4):429–434.
- Setubal A, Alves J, Osório F, et al. Treatment for uterine isthmocele, a pouchlike defect at the site of a Cesarean section scar. J Minim Invasive Gynecol. 2018;25(1):38–46.