Hysteroscopy-assisted Transvaginal Repair without Scar Defect Resection: A Novel Technique for the Treatment of Uterine Niche

Study Objective To describe hysteroscopy-assisted transvaginal repair technique without scar defect resection for uterine niche. Design Surgical video article (Supplemental Videos 1-3). Stepwise narrated video demonstration of the novel technique. A total of 15 women diagnosed as having niche in the uterus were enrolled in our study. Patients provided a signed consent and there are no conflicts of interest. Setting Niche in the uterus is defined as an indentation in the myometrium at the uterine incision owing to healing defects [ 1 Zhou X Yang X Chen H Fang X Wang X. Obstetrical outcomes after vaginal repair of caesarean scar diverticula in reproductive-aged women. BMC Pregnancy Childbirth. 2018; 18: 407 Crossref PubMed Scopus (12) Google Scholar ]. Surgical treatment options for niche include hysteroscopic, laparoscopic, and vaginal surgery [ 2 Donnez O. Cesarean scar defects: management of an iatrogenic pathology whose prevalence has dramatically increased. Fertil Steril. 2020; 113: 704-716 Abstract Full Text Full Text PDF PubMed Scopus (42) Google Scholar ]. Compared with hysteroscopic surgery, regular vaginal surgery may effectively increase the residual myometrium thickness, reducing the risk of subsequent pregnancy [ 3 Vervoort A van der Voet LF Hehenkamp W et al. Hysteroscopic resection of a uterine caesarean scar defect (niche) in women with postmenstrual spotting: a randomised controlled trial. BJOG. 2018; 125: 326-334 Crossref PubMed Scopus (56) Google Scholar , 4 Zhu Q He X Jiang L et al. Effectiveness of hysteroscopic resection of a uterine caesarean niche can be predicted: a prospective cohort study. Sci Rep. 2020; 10: 17424 Crossref PubMed Scopus (7) Google Scholar , 5 Deng K Liu W Chen Y et al. Obstetric and gynecologic outcomes after the transvaginal repair of cesarean scar defect in a series of 183 women. J Minim Invasive Gynecol. 2021; 28: 1051-1059 Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar ]. However, regular vaginal surgery removes the original scar defect followed by suture, which can lead to a new niche after the surgery and may postpone conception because of the new uterine incision [ 6 Family Planning Branch of Chinese Medical AssociationExpert consensus on diagnosis and treatment of uterine niche after cesarean section. Chin J Obstet Gynecol. 2019; 54: 145-148 Google Scholar ]. Here we describe a new technique of hysteroscopy-assisted transvaginal repair for the niche, which does not remove the original scar defect [ 7 Zhang NN Wang GW Zuo N Yang Q. Novel laparoscopic surgery for the repair of cesarean scar defect without processing scar resection. BMC Pregnancy Childbirth. 2021; 21: 815 Crossref PubMed Scopus (2) Google Scholar ]. This surgery may be beneficial for those who plan conceive as soon as possible after the operation. Interventions Hysteroscopy-assisted vaginal surgery without scar defect resection was selected as ideal surgical approach. Hysteroscopy was used for abnormal structures in the niche [ 8 Tanimura S Funamoto H Hosono T et al. New diagnostic criteria and operative strategy for cesarean scar syndrome: endoscopic repair for secondary infertility caused by cesarean scar defect. J Obstet Gynaecol Res. 2015; 41: 1363-1369 Crossref PubMed Scopus (66) Google Scholar , 9 Zhou D Wu F Zhang Q Cui Y Huang S Lv Q. Clinical outcomes of hysteroscopy-assisted transvaginal repair of cesarean scar defect. J Obstet Gynaecol Res. 2020; 46: 279-285 PubMed Google Scholar ]. Opening the peritoneum through the vaginal wall confirmed the position of the niche, and a 2–0 absorbable suture was used to interruptedly suture the upper and lower margins of the scar defect and close the niche (or reduce its size), rather than resection. Hysteroscopy was used again to assess the status of the niche after suture and confirm repair. If unsatisfactory, suture procedure was repeated to close the remaining part of the niche. Conclusion Our novel technique, described and demonstrated in this video article, is an efficacious and viable approach to treat uterine niche. Chinese experts recommend at least a 1-year gap between conventional scar defect resection with suturing and conception, because of the new uterine incision [ 6 Family Planning Branch of Chinese Medical AssociationExpert consensus on diagnosis and treatment of uterine niche after cesarean section. Chin J Obstet Gynecol. 2019; 54: 145-148 Google Scholar ]. In contrast, this novel procedure avoids removal of the original scar defect and the surrounding scar tissue by directly repairing the lower uterine segment. Meanwhile, hysteroscopy can treat abnormal structures in the niche and improve effectiveness. Given that the integrity of the uterine myometrium is retained, this technique may help shorten contraception time after operation. Further studies with larger sample size, longer follow-up time, and more postoperative follow-up indicators, such as fertility outcomes, are needed to comprehensively evaluate the restorative effect of this novel technique.