Introduction
With the increase in the number of cesarean sections in the past three decades, cesarean scar defects (CSDs), as a new type of iatrogenic disease, have gained enormous research momentum. CSD was first described by Morris in 1995 as a pouch-like defect in the anterior uterine wall at the site of a previous cesarean section1. Many patients with CSD are asymptomatic; however, many have reported intermenstrual spotting, dysmenorrhea, dyspareunia, and chronic pelvic pain. Other studies have reported that CSD is an adverse factor for uterine rupture and infertility 2-5.
Magnetic resonance imaging (MRI) and transvaginal sonography (TVS) are useful in the diagnosis of CSD, and both methods can determine the length, width, and depth of the defect and the thickness of the residual myometrium (TRM). In addition, MRI is useful in diagnosing other gynecological diseases such as fibroids, adenomyosis, ovarian tumors, and pelvic diseases.
Adenomyosis, as one of the manifestations of endometriosis that affects women of child-bearing age, is categorized by the presence of hypertrophic smooth muscle derived from ectopic endometrial glands and stroma within the myometrium6, 7. The main symptoms of adenomyosis are menorrhagia, dysmenorrhea, recurrent implantation failure, and miscarriage 8.
MRI and TVS are commonly used in the diagnosis adenomyosis9. However, the sensitivity (88%), specificity (94.6%), and diagnostic accuracy (85–90.8%) of MRI are greater than those of TVS 10, 11. In addition, the positive predictive value (PPV) and negative predictive value (NPV) of MRI were 95.6% and 85.4%, respectively11.
Vaginal repair due to CSDs is a minimally invasive and effective method that maintains fertility 12-14. Patients suffering from intermittent postmenstrual bleeding that underwent vaginal repair still had CSDs, although the size of the defect and the clinical symptoms were improved significantly. In another study, adenomyosis was reported to involve repeated auto-traumatization and self-healing of the endometrial-myometrial junctional zone, thereby affecting myometrium healing 15. This has prompted us to examine the factors involved in the less-than-optimal outcome of vaginal repair.
Here, we hypothesize that adenomyosis might be an adverse factor for uterine repair. We retrospectively reviewed MRI findings of patients with CSDs to determine whether there is a correlation between the occurrence of adenomyosis and the outcome of vaginal repair. We also provide clinical recommendations for the treatment of CSDs.