Objective:To evaluate lung protection of remote limb ischemic preconditioning after pulmonary resection.Methods:Methods sixty adult patients scheduled for elective pulmonary resection, were randomly divided into control group(group C, 30 cases) and remote limb ischemic preconditioning(group RLIP, 30 cases) using a random number table. Before one-lung-ventilation(T0), at 30 minites, 1 hour and 2 hours of OLV(T1, 2, 3), 15minites after re-expansion of the collapsed lung(T4), blood samples were drawn from the radial artery and vein for blood gas analysis, alveolar-arterial oxygen gradient(A-aDO 2)、pulmonary shunt ratio(Qs/Qt)were calculated. Extraction time of closed thoracic drainage tube, length of hospital stay, the incidence of in-hospital complications after operation were recorded. Results:Compared to T0 , each group at T1-T4, A-aDO 2 were obviously increased. We found that at T3, A-aDO 2 of group C increased much more higher and statistically significant( P<0.05). Compared to group RLIP, Qs /Qt of group C were significantly increased at T2( P<0.05). Compared with C group, the expression of microtubule-associated protein 1 light chain 3B in lung tissues was significantly"up-regulated in RLIP group( P<0.05). Followed the extraction time of closed thoracic drainage tube, length of hospital stay, the incidence of in-hospital complications after operation there were no statistically different( P>0.05). Conclusion:Remote limb ischemic preconditioning had some protective effect after pulmonary resection, which mechanism may be related to enhancing autophagy in the operated 1ung tissues of the patients.

BACKGROUND:At present,there are shortcomings and risks in the surgical revision of vertebral bodies that failed to be fixed in clinical practice.To avoid the risks of conventional revision surgery,the cortical bone trajectory technique is used to perform revision surgery on vertebral bodies that failed to be fixed.However,the mechanical properties of cortical bone trajectory technique screws in revision surgery are not clear. OBJECTIVE:The mechanical properties of cortical bone trajectory in lumbar revision surgery were analyzed by the finite element method to provide a theoretical basis for the clinical application of cortical bone trajectory in revision surgery. METHODS:CT scan data of the osteoporotic vertebral body were obtained and the L4 vertebral body model was established.The initial cortical bone trajectory placement and traditional pedicle screw in the L4 vertebral body model were completed,respectively,and their mechanical data were taken as the baseline standard for later evaluation of revision surgical performance.The traditional pedicle screw was removed and the screw path was retained.The cortical bone trajectory screw was used for secondary screw placement on the vertebral body to achieve lumbar refixation.The axial pull-out force,stability,and lumbar motion range of the revised screw were analyzed by the finite element method. RESULTS AND CONCLUSION:(1)The screw axial pull-out force of the cortical bone trajectory revision group was 25.6%higher than that of the traditional pedicle initial group.(2)In the lower,left,and right working conditions,the load-displacement ratio of screws in the cortical bone trajectory revision group increased by 18.5%,41.3%,and 35.0%,respectively,compared with the traditional pedicle initial group.The load-displacement ratio of screws in the cortical bone trajectory revision group was slightly higher than that in the traditional pedicle initial group under the above condition,but there was no statistically significant difference(P>0.05).(3)In anterior and posterior flexion conditions,lumbar motion range in the cortical bone trajectory revision group was increased by 45.5%and 36.1%compared with the traditional pedicle initial group,but there was no statistically significant difference in left bend,right bend,and axial rotation conditions(P>0.05).(4)There were no statistically significant differences in screw axial pull-out force,screw load-displacement ratio,and lumbar motion range between the cortical bone trajectory revision group and cortical bone trajectory initial group(P>0.05).(5)The mechanical data exhibited that although the revised nail track bone was damaged or lost to a certain extent,the mechanical properties of the cortical bone trajectory revision group were still better than those of the traditional pedicle initial group to a certain extent.Moreover,there was no significant difference in the mechanical properties between the cortical bone trajectory revision group and the cortical bone trajectory initial group.It provides a reference for revision surgery of lumbar internal fixation with cortical bone trajectory technique in patients with failed traditional pedicle fixation.