In Vivo Efficacy of an Adhesive Bioresorbable Patch to Treat Aortic Dissections.

Endovascular repair of aortic dissection still presents significant limitations. Preserving the mechanical and biological properties set by the aortic microstructure is critical to the success of implantable grafts. In this paper, we present the performance of an adhesive bioresorbable patch designed to cover the entry tear of aortic dissections. We demonstrate the power of using a biomimetic scaffold in a vascular environment.

Intraamniotic sealing of fetoscopic membrane defects in ex vivo and in vivo sheep models using an integrated semirigid bioadhesive patch.

BACKGROUND: Preterm prelabor rupture of membranes is the most frequent complication of fetoscopic surgery. Strategies to seal the membrane defect created by fetoscopy have been attempted with little success. We previously developed an integrated semirigid bioadhesive patch composed of silicone and hydroxypropyl methylcellulose that achieved ex vivo sealing of membrane defects. OBJECTIVE: To evaluate the feasibility of the insertion of our integrated semirigid bioadhesive patches using a fetoscopic technique and to test the adhesion in ex vivo human membranes and in an in vivo ovine model. STUDY DESIGN: An experimental study involving 2 experiments: (1) ex vivo-human fetal membranes were mounted in a custom-designed model with saline solution simulating intraamniotic pressure. The insertion of 2 different bioadhesive patches made of silicone-hydroxypropyl methylcellulose and silicone-polyurethane-hydroxypropyl methylcellulose was performed through a 12-Fr cannula mimicking fetoscopic surgery technique. The experiment was repeated 10 times with membranes from different donors. Measures included insertion time, successful insertion, and adhesion at 5 minutes; (2) in vivo-16 patches of silicone-hydroxypropyl methylcellulose were inserted by fetoscopy in the amniotic cavity of pregnant sheep (4 bioadhesives per animal, in 4 ewes). Measures included successful insertion, adhesion at 5 minutes, and adhesion at the end of surgery. RESULTS: In the ex vivo insertion study, there was no difference in the insertion time between silicone-hydroxypropyl methylcellulose and silicone-polyurethane-hydroxypropyl methylcellulose patches (P=.49). Insertion was successful in all cases, but complete adhesion at 5 minutes was superior for silicone-hydroxypropyl methylcellulose (P=.02). In the in vivo study, insertion of silicone-hydroxypropyl methylcellulose by fetoscopy was feasible and successful in all cases, and no complications were reported. Adhesion persisted at 5 minutes and at the end of the surgery in 68.8% and 56.3% of the patches, respectively. CONCLUSION: We describe the feasibility of deploying through a fetoscopic trocar a semirigid silicone-hydroxypropyl methylcellulose patch that seals fetal membranes after an invasive fetal procedure. The results warrant further research for improving long-term adhesion and developing a clinically applicable system.

Ex-vivo mechanical sealing properties and toxicity of a bioadhesive patch as sealing system for fetal membrane iatrogenic defects.

Preterm prelabor rupture of membranes (PPROM) is the most frequent complication of fetal surgery. Strategies to seal the membrane defect created by fetoscopy aiming to reduce the occurrence of PPROM have been attempted with little success. The objective of this study was to evaluate the ex-vivo mechanical sealing properties and toxicity of four different bioadhesives integrated in semi-rigid patches for fetal membranes. We performed and ex-vivo study using term human fetal membranes to compare the four integrated patches composed of silicone or silicone-polyurethane combined with dopaminated-hyaluronic acid or hydroxypropyl methylcellulose (HPMC). For mechanical sealing properties, membranes were mounted in a multiaxial inflation device with saline, perforated and sealed with the 4 combinations. We measured bursting pressure and maximum pressure free of leakage (n = 8). For toxicity, an organ culture of membranes sealed with the patches was used to measure pyknotic index (PI) and lactate dehydrogenase (LDH) concentration (n = 5). All bioadhesives achieved appropriate bursting pressures, but only HPMC forms achieved high maximum pressures free of leakage. Concerning toxicity, bioadhesives showed low PI and LDH levels, suggesting no cell toxicity. We conclude that a semi-rigid patch coated with HPMC achieved ex-vivo sealing of iatrogenic defects in fetal membranes with no signs of cell toxicity. These results warrant further research addressing long-term adhesiveness and feasibility as a sealing system for fetoscopy.