Cerclage outcome by the type of suture material (COTS): study protocol for a pilot and feasibility randomised controlled trial

Abstract

BackgroundCervical incompetence is one of the causes of preterm birth and mid-trimester pregnancy loss. Cervical cerclage is a surgical procedure to treat cervical incompetence. Cervical cerclage reduces the incidence of preterm birth in women at risk of recurrent preterm birth, without a statistically significant reduction in perinatal mortality or neonatal morbidity. Multifilament/braided sutures such as Mersilene tape have been traditionally used for cervical cerclage. Braided sutures, particularly mesh-like non-absorbable sutures, have been associated with an increased risk of infection and, hence, some obstetricians prefer to use monofilament/non-braided sutures. However, these claims are not substantiated by any scientific or clinical evidence.We propose a pilot/feasibility study which will provide the necessary information for planning a definitive trial investigating the clinical effectiveness of monofilament non-braided suture materials in reducing pregnancy loss rate following cervical cerclage compared to the traditional multifilament braided sutures.Methods/DesignWomen eligible for elective or ultrasound-indicated cerclage at 12 to 21 + 6 weeks of gestation will be randomised to having the procedure using either a monofilament non-braided suture (Ethilon) or a Multifilament braided suture (Mersilene tape) inserted using a McDonald technique. Consent for participation in the Cerclage outcome by the type of suture (COTS) study will be obtained from each eligible participant.Clinical trials registrationCOTS is registered with the International Standard Research for Clinical Trials (ISRCTN17866773). Registered on 27 March 2013.

Cervical Cerclage

“…Rates of preterm birth less than 35 weeks were similar between polyester braided thread and mersilene tape 68 . An RCT is currently ongoing assessing the type of suture material 69 Evidence level 2+ …”

Management of an incompetent mid-second (mid-2nd) trimester absent ecto-cervix: a case series. Cervical amplification pre-cerclage insertion

“…Evidence behind the varying aspects of the surgical protocol -skin preparation, anaesthetic in ltration, suture type, antibiotic cover and cerclage technique which have previously been largely discussed in treatment protocol, was provided alongside the lack of evidence behind the superiority of any stitch insertion and or technique (2,9,13). Deep angled suture placement as used in this group or super cial circumferential technique is poorly described in literature and its success may be related to the variable cervical architecture.…”

“…Despite infection concerns with the use of braided sutures, none of these techniques nor suture types have been shown to be consistently superior to the others, except in speci c cohorts (9,10).…”

Cerclage: Shirodkar, McDonald, and Modifications

“…toamultifilament braidedsuture (Mersilene tape; Ethicon Inc.) at the time of history-indicated or ultrasound-indicated McDonald cerclage may add to the currently scant data on this topic. 10 Although comparative trials are lacking, retrospective data and the sutures utilized in the various trials demonstrating the efficacy of cerclage may be extrapolated to guide current practice. In the largest RCT comparing use of history-indicated cerclage versus no cerclage in women with history suggestive of or at high-risk for cervical insufficiency, a trial demonstrating benefit of cerclage placement in women with Z3 midtrimester losses or spontaneous preterm births, Mersilene tape (Ethicon Inc.) was used.…”