Sometimes the healing process of the cesarean section scar is incomplete, with a disruption of the myometrium. In the literature there are several names used for this “gap”, being the terms “niche” or isthmocele the most commonly used. The real incidence is unknown however it might range between 24% to 56%. There seems to be a relationship between multiple previous cesarean section and CSD.
Frequently it is asyntomatic, but sometimes is responsible for menorrhagia, abdominal pain, dyspareunia and dysmenorrhea. Infertility might also be present, as the accumulation of blood in the pouch can lead to minimal retrograde passage of blood, to the uterine cavity, especially in retroverted uteri, causing inflammation or an adverse environment for embryo implantation.
Histeroscopy allows for the direct visualization of the defect. When passing throw the cervix, or just after it, a pseudocavity can be seen in the anterior wall. The typical sign is a “double arch”. The dome is often covered with fibrous tissue or congestive endometrium. Depending on the cycle phase blood clots can sometimes be seen. The is usually not necessary, but can be useful to rule out other conditions or to plan the corrective surgery.