(290) The Cx Device: Benchtop Testing of a Medical Device to Treat Cervical Insufficiency

Thursday, February 9, 2023

10:30 AM – 12:00 PM

Objective: A cerclage prevents preterm birth, in part, by compressing the cervix and preventing preterm dilation. However, a cerclage does not prevent preterm birth in all cases and adverse effects can occur. To address the limitations of a cerclage, a proof-of-principle, medical device was designed. Like a cerclage, the device uses a suture to apply compression. Unlike a cerclage, the suture applies compression to polymer plates, which compress the tissue (Figure). Thus, compression forces are distributed over a larger tissue contact area. Called the Cx Device (CxD), our objective was to compare the CxD to a cerclage suture in benchtop tests of 1) cervical laceration and 2) ultrasound-derived cervical length.

Study Design: To simulate a cervical laceration, a previously described silicone cervix model was used. Mersilene tape was sutured to the silicone cervix. The suture was pulled through the silicone until material failure was observed. For the CxD, a polymer plate was sutured to the silicone cervix model and pulled through until failure was observed. The peak load at failure was measured for the Mersilene and the CxD polymer plate (n=5 replicates). To simulate ultrasound-derived cervical length, a custom, cervix-shaped, ultrasound phantom was constructed using Zerdine hydrogel (CIRS). The inside canal of the ultrasound phantom formed a funnel to simulate a short, dilated cervix. A Mersilene cerclage vs. CxD was installed on the ultrasound phantom. The ultrasound phantom was attached to a cerclage simulator (Limbs and Things, Model 80180) and cervical length was measured with a vaginal probe (n=3 replicates) (Philips 3D9-3V).

Results: The peak load at failure of the silicone cervix was significantly higher for the CxD compared with Mersilene (166 Newtons vs. 73 Newtons, p< 0.001). Compared to Mersilene, the closed cervical length was 0.6 cm longer when the CxD was installed (p < 0.01)

Conclusion:

The CxD compresses the cervix over a larger contact area, which significantly decreased laceration risk and improved cervical length in benchtop testing.

Primary & Presenting Author(s)

Michael House, MD (he/him/his)
Professor
Tufts Medical Center
Boston, Massachusetts, United States

Coauthor(s)

DC
Devon Campbell, MSc
Prodct, LLC
Lexington, Massachusetts, United States
SC
Sabrina Craigo, MD
Tufts Medical Center
Boston, Massachusetts, United States