ABSTRACT
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
ABSTRACT
Objective The ileum of porcine intestines with radiofrequency (RF) energy was fused through a novel linkage-type pressure controlled electrode, so as to verify feasibility and security of intestinal reconstruction in the RF energy tissue fusion technology. Methods Fresh porcine intestines were fixed on negative electrode in the order of ‘mucosa-serosa’, and then different compressive pressures （497，796，995，1 194，1 492 kPa）and RF energy were applied to the tissues through positive electrode of pressure cone to complete intestinal anastomosis. Biomechanical properties of the fused area were studied by tensile strength and bursting pressure test, and the thermal diffusion and tissue microstructure also studied. ResultsThe anastomotic tensile strength and bursting pressure could reach （8.73±1.11） N and （8.29±0.41） kPa, respectively, when the energy output power, pressure and welding time were 160 W, 995 kPa and 13 s, respectively, and an intact microstructure with little free collagen in the fused area could be observed. Conclusions The technology of RF energy-based tissue fusion could accomplish fast and stable intestinal tract reconstruction, showing great potential in clinical application. It is of great significance to shorten the operation time, simplify the operation process and improve the operation quality.
ABSTRACT
The aim of this study was to make a comparison between the tissue fusion technique and conventional methods for sealing bowel anastomosis. Eighteen female domestic pigs (Suidae, Sus) were used in our study. Tissue-fused anastomoses (LigaSure groups) were made in 13 animals (5 anastomoses per animal), which were subdivided into 4 groups according to different manufacturing settings: "LigaSure-L-1" and "LigaSure-L-2", with low energy output level with 1 or 2 device-activated tissue sealing times, and "LigaSure-M" and "LigaSure-H", with medium or high energy output level. As controls, automatically stapled (GIA group) and hand-sewn (suture group) anastomoses were utilized in 3 and 2 animals, respectively. There was no statistical difference in the overall leakage rate between the GIA group (6.7%) and the LigaSure groups (15%) (P=1.000). There was less proliferating epithelium covering the anastomosis gap in the LigaSure groups compared with the other two groups. The gap between the two extremities of muscular layers of the anastomosis in the LigaSure groups was filled with collagen fibers. More proliferating cell nuclear antigen (PCNA)-positive cells were found in the anastomoses of the LigaSure groups compared with the other two groups (P=0.010). Our results showed that the tissue fusion technology was a feasible and safe method for anastomoses.