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Study information - 2Close study


Single versus double layer closure of the caesarean (uterine) scar in the prevention of gynaecological symptoms in relation to niche development.


Objective
Double layer closure compared to single layer closure of the uterus after a caesarean section (CS) leads to a thicker myometrial layer at the site of the CS scar (residual myometrium) and possibly decreases the development of niches. A niche is a CS defect at the site of the uterine scar and is associated with gynaecological symptoms including postmenstrual spotting (OR 3.1 (1.5-6.3)). It is also associated with failure of trial of labour after CS and possibly with subfertility. In the Netherlands single layer closure of the uterus is performed by 92% of the gynaecologists.

We hypothesize that double layer closure of the uterine scar using unlocked continuous running sutures reduces menstrual disorders and pain and subfertility in relation to niche development and increases QOL and improves sexual functioning, compared to single layer closure.


Study design
Cost effectiveness analysis alongside multicenter randomised controlled trial (superiority). Patients and ultrasound examiners will be blinded for allocation.

Study population
Inclusion criteria:
  •  Patients undergoing their first caesarean section.
  •  Sufficient command of the Dutch or English language
  •  > 18 years old
Exclusion criteria:
  • Inadequate possibility for counseling (e.g. indication for emergency CS, severe pain without accurate therapy) if patients were not informed about the study earlier in the pregnancy
  • Previous uterine major surgery (e.g. laparoscopic or laparotomic fibroid resection, septum resection)
  • Patient with known cause of menstrual disorder (cervical dysplasia, communicating hydrosalpinx, uterine anomaly or endocrine disorders disturbing ovulation
  • Placenta in- or percreta in current pregnancy
  • 3 or more fetus in current pregnancy
Intervention
Double layer closure (unlocked) continuous running suture of the uterus using multifilament material (instructed by e-learning) compared with usual (single layer) closure of the uterus, using a continuous running multifilament suture.

Outcome measures
Primary outcome: post- and intermenstrual spotting 9 months after randomization. Secondary outcome: menstrual pattern (score card) and dysmenorrhoe (VAS), Quality of life (SF36 & EQ-5D-5L), societal reintegration (PROMIS), sexual function (FSFI), Niche (characteristics), complications, surgery time and costs, % of ongoing pregnancies, life birth rate and time to conceive in women willing to conceive.

Power/data analysis
We use a superiority design. Literature for making reliable estimations is scarce. We have used baseline data from the HysNiche study and preliminary data of a retrospective study among women that had a CS or vaginal delivery in 2011 in the VU Medical Centre or Deventer Ziekenhuis. We estimate that in the total group the average number of spotting days is 3.5 days/month. We consider a 15% reduction in the number of spotting days clinically relevant (average 0,5 day/month/woman reduction). Assuming a SD of 3.4 and predefining the p-value on 0.05, taking into account a non-normal distribution 1946 women are needed to achieve a power of 0.90. Increasing the sample size to take into account 15% of women unevaluable for the primary outcome, 2290 women need to be included.


Economic evaluation
Both a cost-effectiveness and cost-utility analysis will be performed with a time horizon of 9 months to relate the difference in societal and healthcare costs between double layer and single layer unlocked uterine closure during a caesarean section to the difference in clinical effects.

Time schedule
48 months; 6 months preparation, 24 months inclusion, 6 months analysis and report.

Projectleaders
Dr. J.A.F. Huirne, gynaecologist, VUmc Amsterdam
Prof. dr. C.J.M. de Groot, gynaecologist (obstetrics), VUmc Amsterdam
Prof. dr. C.B. Lambalk, gynaecologist (fertility), VUmc Amsterdam

Health Technology Assessment
Dr. J.E. Bosmans, assistant professor, Afd. Gezondheidswetenschappen VU

Methodology
Dr. S.E. Zwolsman, clinical epidemiologist, AMC Amsterdam

Subsidy
ZonMw www.zonmw.nl

Contact (researcher)

Drs. Sanne Stegwee
PhD candidate, VUmc Amsterdam
Tel: 06-19196752 Email: s.stegwee@vumc.nl