Adhesion of surgical sealants used in cardiothoracic and vascular surgery

International audience; Surgical sealants are widely used in cardiothoracic and vascular surgery essentially for hemostasis and sealing. Their adhesive properties have mainly been studied by clinical experiments. The objective of this study is to measure adhesion of the three main types of surgical sealant used in cardiothoracic and vascular surgery under normalized realistic conditions. The bulge-and-blister test was used to quantify adhesive performances of three types of surgical adhesives: cyanoacrylates, polyethylene glycol (PEG), and aldehydes. Samples were composed of two circular layers of equine pericardium glued by the surgical sealant studied. Comparative adhesion testing was carried out in eight samples bonded with a Dermabond® (cyanoacrylate), five samples with Bioglue® (aldehyde), four samples with Coseal® (PEG), and thirteen samples bonded with an industrial cyanoacrylate. Scanning electron microscope (SEM) observations of cross-sections of samples glued by Dermabond® and environmental scanning electron microscopy (ESEM) images of samples composed of equine pericardium glued by Bioglue® were also performed. The average value of the adhesion energy is 2.3+/-1.5 J.m-2 for samples glued with Dermabond®, 6.04+/-1.61 J.m-2 with Bioglue®, 2.37+/-1.25 J m-2 with Coseal®, 3.74+/-1.33 J m-2 with the industrial cyanoacrylate glue in surgical conditions. SEM observations of cross-sections of samples glued by Dermabond® showed a failure at the interface between the glue and the pericardial layer. ESEM observations have revealed a majority of regions where the glue is not linked to the pericardium. Adhesive performance measurements and microscopy observations in surgical conditions show that surgical sealants adhesion is weak and explain their poor efficacy in clinical practice. To improve adhesion in the surgical field, we need to focus on achieving a better cohesion between the adhesive and the substrate by modifying conditions adhesive bonding and consequently tend toward cohesive failure.