Postoperative complications after robotic resection of colorectal cancer:An analysis based on 5-year experience at a large-scale center

BACKGROUND As a common gastrointestinal malignancy,colorectal cancer(CRC)poses a serious health threat globally.Robotic surgery is one of the future trends in surgical treatment of CRC.Robotic surgery has several technical advantages over laparoscopic surgery,including 3D visualization,elimination of the fulcrum effect,and better ergonomic positioning,which together lead to better surgical outcomes and faster recovery.However,analysis of independent factors of postoperative complications after robotic surgery is still insufficient.AIM To analyze the incidence and risk factors for postoperative complications after robotic surgery in patients with CRC.METHODS In total,1040 patients who had undergone robotic surgical resection for CRC between May 2015 and May 2020 were analyzed retrospectively.Postoperative complications were categorized according to the Clavien-Dindo(C-D)classification,and possible risk factors were evaluated.RESULTS Among 1040 patients who had undergone robotic surgery for CRC,the overall,severe,local,and systemic complication rates were 12.2%,2.4%,8.8%,and 3.5%,respectively.Multivariate analysis revealed that multiple organ resection(P<0.001)and level III American Society of Anesthesiologists(ASA)score(P=0.006)were independent risk factors for overall complications.Multivariate analysis identified multiple organ resection(P<0.001)and comorbidities(P=0.029)as independent risk factors for severe complications(C-D grade III or higher).Regarding local complications,multiple organ resection(P=0.002)and multiple bowel resection(P=0.027)were independent risk factors.Multiple organ resection(P<0.001)and level III ASA score(P=0.007)were independent risk factors for systemic complications.Additionally,sigmoid colectomy had a lower incidence of overall complications(6.4%;P=0.006)and local complications(4.7%;P=0.028)than other types of colorectal surgery.CONCLUSION Multiple organ resection,level III ASA score,comorbidities,and multiple bowel resection were risk factors for postoperative complications,with multiple organ resection being the most likely.

Cooperative trajectory optimization of UAVs in approaching stage using feedback guidance methods

This paper mainly studies the problem of using UAVs to provide accurate remote target indication for hypersonic projectiles.Based on the optimal trajectory trends and feedback guidance methods,a new cooperative control algorithm is proposed to optimize trajectories of multi-UAVs for target tracking in approaching stage.Based on UAV kinematics and sensor performance models,optimal trajectory trends of UAVs are analyzed theoretically.Then,feedback guidance methods are proposed under the optimal observation trends of UAVs in the approaching target stage,producing trajectories with far less computational complexity and performance very close to the best-known trajectories.Next,the sufficient condition for the UAV to form the optimal observation configuration by the feedback guidance method is presented,which guarantees that the proposed method can optimize the observation trajectory of the UAV in approaching stage.Finally,the feedback guidance method is numerically simulated.Simulation results demonstrate that the estimation performance of the feedback guidance method is superior to the Lyapunov guidance vector field(LGVF)method and verify the effectiveness of the proposed method.Additionally,compared with the receding horizon optimization(RHO)method,the proposed method has the same optimization ability as the RHO method and better real-time performance.