Technical aspects of the laparoscopic niche resection, a step-by-step tutorial.

The technique of a laparoscopic niche resection is described in ten steps and alternative steps for future studies are discussed.

The HysNiche trial: hysteroscopic resection of uterine caesarean scar defect (niche) in patients with abnormal bleeding, a randomised controlled trial.

BACKGROUND: A caesarean section (CS) can cause a defect or disruption of the myometrium at the site of the uterine scar, called a niche. In recent years, an association between a niche and postmenstrual spotting after a CS has been demonstrated. Hysteroscopic resection of these niches is thought to reduce spotting and menstrual pain. However, there are no randomised trials assessing the effectiveness of a hysteroscopic niche resection. METHODS/DESIGN: We planned a multicentre randomised trial comparing hysteroscopic niche resection to no intervention. We study women with postmenstrual spotting after a CS and a niche with a residual myometrium of at least 3 mm during sonohysterography. After informed consent is obtained, eligible women will be randomly allocated to hysteroscopic resection of the niche or expectant management for 6 months. The primary outcome is the number of days with postmenstrual spotting during one menstrual cycle 6 months after randomisation. Secondary outcomes are menstrual characteristics, menstruation related pain and experienced discomfort due to spotting or menstrual pain, quality of life, patient satisfaction, sexual function, urological symptoms, medical consultations, medication use, complications, lost productivity and medical costs. Measurements will be performed at baseline and at 3 and 6 months after randomisation. A cost-effectiveness analysis will be performed from a societal perspective at 6 months after randomisation. DISCUSSION: This trial will provide insight in the (cost)effectiveness of hysteroscopic resection of a niche versus expectant management in women who have postmenstrual spotting and a niche with sufficient residual myometrium to perform a hysteroscopic niche resection. TRIAL REGISTRATION: Dutch Trial Register NTR3269 . Registered 1 February 2012. ZonMw Grant number 80-82305-97-12030.

Why do niches develop in Caesarean uterine scars? Hypotheses on the aetiology of niche development.

Caesarean section (CS) results in the occurrence of the phenomenon 'niche'. A 'niche' describes the presence of a hypoechoic area within the myometrium of the lower uterine segment, reflecting a discontinuation of the myometrium at the site of a previous CS. Using gel or saline instillation sonohysterography, a niche is identified in the scar in more than half of the women who had had a CS, most with the uterus closed in one single layer, without closure of the peritoneum. An incompletely healed scar is a long-term complication of the CS and is associated with more gynaecological symptoms than is commonly acknowledged. Approximately 30% of women with a niche report spotting at 6-12 months after their CS. Other reported symptoms in women with a niche are dysmenorrhoea, chronic pelvic pain and dyspareunia. Given the association between a niche and gynaecological symptoms, obstetric complications and potentially with subfertility, it is important to elucidate the aetiology of niche development after CS in order to develop preventive strategies. Based on current published data and our observations during sonographic, hysteroscopic and laparoscopic evaluations of niches we postulate some hypotheses on niche development. Possible factors that could play a role in niche development include a very low incision through cervical tissue, inadequate suturing technique during closure of the uterine scar, surgical interventions that increase adhesion formation or patient-related factors that impair wound healing or increase inflammation or adhesion formation.

Minimally invasive therapy for gynaecological symptoms related to a niche in the caesarean scar: a systematic review.

BACKGROUND: Various therapies are currently used to treat symptoms related to the niche (an anechoic area) in the caesarean scar, in particular to treat abnormal uterine bleeding (AUB). OBJECTIVE: To systematically review the available literature reporting on the effect of various therapies on niche-related symptoms. SEARCH STRATEGY: A systematic search of MEDLINE, Embase, Cochrane, trial registers and congress abstracts from AAGL and ESGE was performed. SELECTION CRITERIA: Articles reporting on the effectiveness of therapies other than hysterectomy in women with niche-related symptoms were included. Studies were included if they reported one of the following outcomes: effect on AUB, pain relief, sexual function, quality of life (QOL), and surgical, anatomic, fertility, or pregnancy outcome. DATA COLLECTION AND ANALYSIS: Two authors independently selected the articles to be included. The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed. A standardised checklist was used to score the methodological quality of the included studies. MAIN RESULTS: Twelve studies were included, reporting on hysteroscopic niche resection (eight studies, 384 patients), laparoscopic repair (one study, 13 patients), (laparoscopic assisted) vaginal repair (two studies, 47 patients), and oral contraceptives (OCs) (one study, 11 patients). Reported AUB improved in the vast majority of the patients after these interventions, ranging from 87 to 100%. The rate of complications was low. Pregnancies were reported after therapy; however, sample sizes and follow-up were insufficient to study fertility or pregnancy outcome. The methodological quality of the selected papers was considered to be moderate to poor, and was therefore insufficient to make solid conclusions. AUTHOR'S CONCLUSIONS: More evidence is needed before (surgical) niche interventions are implemented in daily practice.