Objective Aiming at improving biomechanical strength of the anastomotic stoma as well as reducing tissue thermal damage, a novel radiofrequency (RF) tissue welding electrode was developed. Methods A novel electrode with a hollow structure on the surface ( the plum electrode) was designed and the ring electrode was used as control group to conduct the welding of intestinal tissues based on RF energy. Biomechanical properties of anastomotic stoma were studied by shear test and burst pressure test. The tissue thermal damage during welding was investigated by finite element electro-thermal-mechanical multi-field coupling simulation analysis and thermocouple probe, and the tissue microstructures were also studied. Results Under 120 W RF energy, 8 s welding duration and 20 kPa compression pressure, the anastomotic stoma had the optimal biomechanical properties. Compared with the ring electrode group, biomechanical strength of the anastomotic stoma in plum electrode group was higher, with the shear strength and burst pressure increasing from (9. 7±1. 47) N, (84. 0±5. 99) mmHg to (11. 1±1. 71) N, (89. 4±6. 60) mmHg, respectively. There was a significant reduction in tissue thermal damage, and intact and fully fused stomas could be formed in anastomotic area. Conclusions The proposed novel electrode could improve biomechanical strength of the anastomosis as well as reduce tissue hermal damage, thus achieve better fusion. The research result provide references for realizing the seamless connection of human lumen tissues

Objective To improve the efficiency and quality of end-to-end anastomosis,a novel degradable vascular anastomotic device was designed,and the relationship between pressure distances and biomechanical properties of the anastomotic stoma was explored.Methods The three-dimensional(3D)structure of the vascular anastomotic device was designed and the prototype was fabricated with extruded high-purity magnesium.The finite element model of the end-to-end vascular anastomosis was established to study the stress distributions of the anastomotic end face under different pressure distances(0.4,0.5,0.6,0.7,and 0.8 mm)and their change rules.In vitro experiments were conducted to verify the rationality of the finite element results as well as the feasibility and effectiveness of the vascular anastomotic device.Results When the pressure distance was 0.6 mm,the anastomotic tensile force,and burst pressure could reach(11.79±0.64)N and(39.32±2.99)kPa,respectively,meeting the clinical requirement for the strength of vascular anastomosis,and with the minimal mechanical damages to tissues.Conclusions The device designed in this study can be used for vascular anastomosis by adjusting the pressure distance,and it can improve operation efficiency,reduce mechanical damage to tissues,and further improve the quality of anastomosis.These results provide an essential reference for the design of degradable vascular anastomotic devices.