Introduction
Cesarean section (CS) is one of the most common performed large surgical intervention in, and its incidence has been increasing steadily, accounting worldwide for one-third of all deliveries.1Only recently we became aware of long-term morbidity related to these CS that may be related to a defect in the uterine CS scar, also called a niche. It is defined as a disruption of the integrity of the myometrium at the site of the cesarean scar with a minimum depth of 2 mm using (sono)hysterography.2Other diagnostic methods include magnetic resonance imaging (MRI) or hysteroscopy.3-5 Niches also called Cesarean scar defects are reported in 49.6% ~ 64.5% in patients with at least one previous CS, and it increases along with the number of CSs up to 100% women with 3 or more CSs.6-8
Niches are associated with gynecological symptoms like postmenstrual spotting, chronic pelvic pain, infertility and complications in subsequent pregnancy. Postmenstrual bleeding is the most common symptom that is reported in 29%-82% in women with a niche. It severely affects women’s health and quality of life, in particular due to its unpredicted nature.3, 9-11 In China, more and more women with a diagnosed niche in the uterine scar ask for surgery or medical treatment in order to treat postmenstrual spotting according to the clinical experience.
So far, international acknowledged guidelines on the preferred treatment for this indication are lacking. Non-surgical and surgical methods have been reported for the treatment of niche related bleeding symptoms.12, 13 Surgical options include laparoscopic, transvaginal and hysteroscopic niche resections. In women with a relatively small niche with adequate residual myometrial thickness (mostly>2.5mm), a hysteroscopic niche resection is the least invasive approach.14-16 A hysteroscopic niche resection reduces postmenstrual spotting with an average of 4 days.12, 17 Non-surgical methods include continuous or cyclic hormonal therapies and Levenorgestrel-releasing intrauterine device (LNG-IUD).12 Although the number of studies evaluating the effect of these medical treatments in the reduction of postmenstrual spotting is very limited. Concerning LNG-IUD only one study, including 6 patients only, indicated a positive effect.18As far as we are aware of comparative studies between hysteroscopic niche resection and LNG-IUD in the treatment of postmenstrual spotting lacking. Therefore, we conducted a prospective cohort study to compare the effect of a hysteroscopic niche resection and LNG-IUD on niche related postmenstrual spotting.