Post-caesarean Niche (Isthmocele) in Uterine Scar: An Update

Abstract

Uterine niche is one of the emerging complications of caesarean section. With rising caesarean rates, the caesarean-related iatrogenic complications are also on the rise. These include placenta accreta, scar ectopic pregnancy and uterine niche which is a newer entity being described in the recent literature. Uterine niche, also described as uterine isthmocele, caesarean scar defect and diverticulum, is an iatrogenic defect in the myometrium at the site of previous caesarean scar due to defective tissue healing. Patients may have varied symptoms including abnormal uterine bleeding, post-menstrual spotting and infertility, though many women may be asymptomatic and diagnosed incidentally. Diagnosis is made radiologically by transvaginal sonography, saline instillation sonohysterography or magnetic resonance imaging. Occurrence of niche may be prevented by using correct surgical technique during caesarean. Patients may be managed medically; however, subfertility and persistent symptoms may require surgical correction either by hysteroscopic resection or transabdominal or transvaginal repair. This mini-review comprehensively covers the potential risk factors, clinical presentation, diagnosis and management of this increasingly encountered condition due to rising caesarean rates.

Keywords: Caesarean scar defect; Isthmocele; Uterine niche.

Fig. 1

2-D ultrasound showing uterus, cervix, niche (n) measuring 1 cm, collection in the niche (C) and bladder (B) (courtesy Prof. Vatsla Dadhwal)

Fig. 2

Intraoperative findings of transabdominal repair a bulge prior to incision, b after incision over niche, c after excision of fibrotic tissue from the niche edges (courtesy Prof. Vatsla Dadhwal)