Z Geburtshilfe Neonatol 2011; 215 - FV12_05
DOI: 10.1055/s-0031-1293280

Ex vivo fetal membrane repair using the mussel-mimetic sealant

N Ochsenbein 1, C Haller 1, P Messersmith 2, E Mazza 3, R Zimmermann 1, M Ehrbar 1
  • 1Klinik für Geburtshilfe, Universitätsspital Zürich, Zürich, Schweiz
  • 2Biomedical Engineering Dept., Northwestern University, Evanston, Illinois, USA
  • 3Mechanical Engineering Department, 8092 Zurich, Switzerland

Ziel: Preterm prelabour rupture of the fetal membranes (PPROM) is an unsolved complication in pregnancy which limits the developing field of fetal surgery. The aim was to evaluate ex vivo sealing properties of a new mussel-mimetic tissue adhesive (mussel glue, MG) using punctured synthetic membranes.

Methodik: Test membranes were clamped on a biomechanical test device, which by biaxial stretching permits to evaluate the mechanical properties of fetal membranes under close to physiological conditions. Synthetic membranes with 3 different thicknesses and stiffness were punctured with a punch device of 3.0mm diameter and sealed using MG. The gluing properties of MG were confirmed on trocar (3.5mm) punctured, semi-wet fetal membranes and compared with fibrin glue. To estimate the glue stability in vivo, the sensitivity of MG and fibrin glue plugs towards proteolytic enzymes was tested in vitro in the presence of plasmin and collagenase.

Ergebnis: MG efficiently sealed punctured synthetic and fetal membranes. The failure of the MG plug on synthetic membranes was mainly due to large deformations (140% increase in defect size and 80% in plug size) during mechanical loading. Thus, the achieved critical pressure correlated with the membrane stiffness and reached 45mbar (=34mmHg). Fetal membranes that were punctured with a 3.5mm trocar and sealed under wet gluing conditions with MG resisted pressures of 48.6mbar (36.5mmHg), whereas with fibrin glue only 4.8 mbar (3.6mmHg) was reached. Fibrin glue could only reliably seal the membrane defects (47.3 mbar, 35.5mmHg), when applied on the dry surface. MG showed prolonged stability in a proteolytic environment compared to fibrin glue, indicating its superior long-term stability.

Schlussfolgerung: MG is a material that seals fetal membranes even under wet conditions and resists pressures as measured in vivo. Its insensitivity towards proteolytic degradation makes it promising for the repair of iatrogenic membrane defects.

PPROM - mussel glue