This study aimed to evaluate the feasibility and effectiveness of closing the small bowel in an ex vivo porcine model with high-frequency welding device. A total of 100 porcine small bowels were divided into two groups, and then were closed with two different methods. The fifty small bowels in experimental group were closed by the high-frequency welding device, and the other fifty small bowels in comparison group were hand-sutured. All the small bowels were subjected to leak pressure testing later on. The speed of closure and bursting pressure were compared. The 50 porcine small bowels closed by the high-frequency welding device showed a success rate of 100%. Compared with the hand-sutured group, the bursting pressures of the former were significantly lower (P<0.01) and the closing process was significantly shorter (P<0.01). The pathological changes of the closed ends mainly presented as acute thermal and pressure induced injury. Experimental results show that the high-frequency welding device has higher feasibility in closing the small bowel.
ObjectiveTo summarize the research progress of difficulty in removing of locking plate and screw. MethodsThe domestic and foreign related literature about difficulty in removing of locking plate and screw was reviewed. The incidence, the reason, preventive measure, removing method, and its advantages and disadvantages were summarized and analyzed. ResultsWith the popularization of locking plate application, cases with difficulty in removing locking screw have significantly increased compared with non-locking plate, so it has become a new clinical problem. The main reasons are stripping, cross-threading, and cold-welding. In recent years, for the difficulty in removing of locking plate and screw, some special extraction tools and new extraction methods have developed, but each has its defects and indications. ConclusionSufficient preoperative preparation, being familiar with its advantage and disadvantage as well as its indications are necessary. The specific situations of patient, including the reason, the screw, the plate, the incision, the bone quantity, and existing equipment, should be comprehensively considered to select appropriate methods.
This study aims to overcome the shortcomings such as low efficiency, high cost and difficult to carry out multi-parameter research, which limited the optimization of infusion bag configuration and manufacture technique by experiment method. We put forward a fluid cavity based finite element method, and it could be used to simulate the stress distribution and deformation process of infusion bag under external load. In this paper, numerical models of infusion bag with different sizes was built, and the fluid-solid coupling deformation process was calculated using the fluid cavity method in software ABAQUS subject to the same boundary conditions with the burst test. The peeling strength which was obtained from the peeling adhesion test was used as failure criterion. The calculated resultant force which makes the computed peeling stress reach the peeling strength was compared with experiment data, and the stress distribution was analyzed compared with the rupture process of burst test. The results showed that considering the errors caused by the difference of weak welding and eccentric load, the flow cavity based finite element method can accurately model the stress distribution and deformation process of infusion bag. It could be useful for the optimization of multi chamber infusion bag configuration and manufacture technique, leading to cost reduction and study efficiency improvement.