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.