Cesarean Scar Defect Formation :
– It forms after cesarean delivery, at the site of hysterotomy, on the anterior wall of the uterine isthmus.
– Improper healing of the cesarean incision leads to thinning of the anterior uterine wall, which creates an indentation & a fluid-filled pouch at the cesarean scar site.
Cesarean Scar Defect Risk Factors :
– The exact reason why a niche develops has not yet been determined; however, Surgical techniques that may increase the chance of niche development include low (cervical) hysterotomy, single-layer uterine wall closure, use of locking sutures, closure of hysterotomy with endometrial-sparing technique & multiple cesarean deliveries. Patients with medical conditions that may impact wound healing (such as DM & smoking) may be at increased risk for niche formation.
Cesarean Scar Defect Complications :
– The presence of fibrotic tissue in the niche acts like a valve, leading to the accumulation of blood in this reservoir-like area. A niche thus can cause delayed menstruation, resulting in abnormal bleeding, pelvic pain, vaginal discharge, dysmenorrhea, dyspareunia & infertility. Accumulated blood in this area can ultimately degrade cervical mucus & sperm quality, as well as inhibit sperm transport, a proposed mechanism of infertility. Women with a niche who conceive are at potential risk for cesarean scar ectopic pregnancy, with the embryo implanting in the pouch & subsequently growing & developing improperly.
Cesarean Scar Defect Evaluation :
– The best time to assess for the abnormality is after the patient’s menstrual cycle, when the endometrial lining is at its thinnest & recently menstruated blood has collected in the defect (this can highlight the niche on imaging).
– Transvaginal U/S or saline-infusion sonohysterogram serve as a first-line test for inoffice diagnosis.
Cesarean Scar Defect Treatment :
– Treatments for cesarean scar defect vary dramatically & include hormonal therapy,hysteroscopic resection, laparoscopic repair & hysterectomy.
– To promote fertility, the fibrotic tissue must be removed as the cesarean scar defect in a gravid uterus represents a risk for uterine rupture. The laparoscopic approach allows the defect to be repaired & restore the integrity of the myometrium.
Technique of uterine closure (Uptodate) :
– Routine manual/instrumental cervical dilatation before closing the uterus is unnecessary in both laboring and non-laboring women.
– Do not irrigate the uterus with antibiotic solution before closure.
– Choice of suture is largely based on personal preference.
– Myometrial closure: perform a 2-layer, continuous closure with delayed absorbable synthetic suture incorporating all of the muscle to avoid bleeding from the incision edges.
– We do not use locking sutures unless arterial bleeding is evident.
– The endometrial layer should probably be included in the full thickness myometrial closure.
– Perform a 2-layer rather than a single-layer uterine closure, but use a single-layer closure when a tubal ligation is performed concurrently. If a single-layer closure is performed to save time, we suggest an unlocked technique. A double (or even triple)- layer closure may be necessary when the myometrium is thick, such as with a classical incisions.
– Do not close the visceral or parietal peritoneum because it saves time and there is no convincing evidence of harm (increased adhesion formation).