Gallstone disease and complications from gallstones are a common clinical problem.The clinical presentation ranges between being asymptomatic and recurrent attacks of biliary pain requiring elective or emergency treat...Gallstone disease and complications from gallstones are a common clinical problem.The clinical presentation ranges between being asymptomatic and recurrent attacks of biliary pain requiring elective or emergency treatment.Bile duct stones are a frequent condition associated with cholelithiasis.Amidst the total cholecystectomies performed every year for cholelithiasis,the presence of bile duct stones is 5%-15%;another small percentage of these will develop common bile duct stones after intervention.To avoid serious complications that can occur in choledocholithiasis,these stones should be removed.Unfortunately,there is no consensus on the ideal management strategy to perform such.For a long time,a direct open surgical approach to the bile duct was the only unique approach.With the advent of advanced endoscopic,radiologic,and minimally invasive surgical techniques,however,therapeutic choices have increased in number,and the management of this pathological situation has become multidisciplinary.To date,there is agreement on preoperative management and the need to treat cholelithiasis with choledocholithiasis,but a debate still exists on how to cure the two diseases at the same time.In the era of laparoscopy and miniinvasiveness,we can say that therapeutic approaches can be performed in two sessions or in one session.Comparison of these two approaches showed equivalent success rates,postoperative morbidity,stone clearance,mortality,conversion to other procedures,total surgery time,and failure rate,but the onesession treatment is characterized by a shorter hospital stay,and more cost benefits.The aim of this review article is to provide the reader with a general summary of gallbladder stone disease in association with the presence of common bile duct stones by discussing their epidemiology,clinical and diagnostic aspects,and possible treatments and their advantages and limitations.展开更多
Gallstones and common bile duct calculi are found to be associated in 8%-20% of patients, leading to possible life-threatening complications, such as acute biliary pancreatitis, jaundice and cholangitis. The gold stan...Gallstones and common bile duct calculi are found to be associated in 8%-20% of patients, leading to possible life-threatening complications, such as acute biliary pancreatitis, jaundice and cholangitis. The gold standard of care for gallbladder calculi and isolated common bile duct stones is represented by laparoscopic cholecystectomy and endoscopic retrograde cholangiopancreatography, respectively, while a debate still exists regarding how to treat the two diseases at the same time. Many therapeutic options are also available when the two conditions are associated, including many different types of treatment, which local professionals often administer. The need to limit maximum discomfort and risks for the patients, combined with the economic pressure of reducing costs and utilizing resources, favors single-step procedures. However, a multitude of data fail to strongly demonstrate the superiority of any technique(including a two or multi-step approach), while rigorous clinical trials that include so many different types of treatment are still lacking, and it is most likely unrealistic to conduct them in the future. Therefore, the choice of the best management is often led by the local presence of professional expertise and resources, rather than by a real superiority of one strategy over another.展开更多
This research furthers the development of a closed-form solution to the angles-only initial relative orbit determination problem for non-cooperative target close-in proximity operations when the camera offset from the...This research furthers the development of a closed-form solution to the angles-only initial relative orbit determination problem for non-cooperative target close-in proximity operations when the camera offset from the vehicle center-of-mass allows for range observability.In previous work,the solution to this problem had been shown to be non-global optimal in the sense of least square and had only been discussed in the context of Clohessy–Wiltshire.In this paper,the emphasis is placed on developing a more compact and improved solution to the problem by using state augmentation least square method in the context of the Clohessy–Wiltshire and Tschauner–Hempel dynamics,derivation of corresponding error covariance,and performance analysis for typical rendezvous missions.A two-body Monte Carlo simulation system is used to evaluate the performance of the solution.The sensitivity of the solution accuracy to camera offset,observation period,and the number of observations are presented and discussed.展开更多
Rendezvous orbital dynamics and control （RODC） is a key technology for operating space rendezvous and docking missions. This paper surveys the studies on RODC. Firstly, the basic relative dynamics equation set is in...Rendezvous orbital dynamics and control （RODC） is a key technology for operating space rendezvous and docking missions. This paper surveys the studies on RODC. Firstly, the basic relative dynamics equation set is introduced and its improved versions are evaluated. Secondly, studies on rendezvous trajectory optimization are commented from three aspects： the linear rendez- vous, the nonlinear two-body rendezvous, and the perturbed and constrained rendezvous. Thirdly, studies on relative navigation are briefly reviewed, and then close-range control methods including automated control, manual control, and telecontrol are analyzed. Fourthly, advances in rendezvous trajectory safety and robust analysis are surveyed, and their applications in trajectory optimization are discussed. Finally, conclusions are drawn and prospects of studies on RODC are presented.展开更多
AIM: To investigate our clinical experience with combined laparo-endoscopic Rendezvous (RV) for the treatment of patients affected by gallstones and common bile duct (CBD) stones and especially to study the never eval...AIM: To investigate our clinical experience with combined laparo-endoscopic Rendezvous (RV) for the treatment of patients affected by gallstones and common bile duct (CBD) stones and especially to study the never evaluated opinion of the endoscopist concerning the difficulty of the intraoperative endoscopic procedure during the RV in comparison with standard endoscopic retrograde cholangio-pancreatography (ERCP). METHODS: Eighty consecutive patients affected by cholecystolithiasis and diagnosed or suspected CBD stones were treated with a standardized "tailored" RV. The relevant technical features, the feasibility, the effectiveness in stone clearance, the safety but also the simple evaluation of difficulty and agreement of the endoscopist were analyzed with a questionnaire. RESULTS: The feasibility was 97.5% and the effectiveness 100% concerning CBD clearance and solution of coexisting problems at the papilla. Minor morbidity was 3.3%, the operating time was prolonged by a mean of 14 min, the mean hospital stay was 3.8 d and only one stone’s recurrence occurred. The endoscopist evaluated the procedure to be simpler than standard ERCP-ES in 81.2% of the cases.CONCLUSION: Simultaneous RV carries higheffectiveness and safety at least comparable to those reported for other options. The endoscopist is very often satisfied with this approach because of the minimization of some steps of the endoscopic procedure and avoidance of relevant iatrogenic risk factors. If the mandatory collaboration between surgeons and endoscopists is guaranteed, this approach can often be preferable for the patient, the surgeon, the endoscopist and the hospital.展开更多
In the treatment of patients with symptomatic cholelithiasis and choledocholithiasis (CBDS) detected during intraoperative cholangiography (IOC),or when the preoperative study of a patient at intermediate risk for CB... In the treatment of patients with symptomatic cholelithiasis and choledocholithiasis (CBDS) detected during intraoperative cholangiography (IOC),or when the preoperative study of a patient at intermediate risk for CBDS cannot be completed due to the lack of imaging techniques required for confirmation,or if they are available and yield contradictory radiological and clinical results,patients can be treated using intraoperative endoscopic retrograde cholangiopancreatography (ERCP) during the laparoscopic treatment or postoperative ERCP if the IOC finds CBDS.The choice of treatment depends on the level of experience and availability of each option at each hospital.Intraoperative ERCP has the advantage of being a single-stage treatment and has a significant success rate,an easy learning curve,low morbidity involving a shorter hospital stay and lower costs than the two-stage treatments (postoperative and preoperative ERCP).Intraoperative ERCP is also a good salvage treatment when preoperative ERCP fails or when total laparoscopic management also fails.展开更多
Despite improvements in endoscopic technologies and accessories, development of advanced endoscopy fellowship programs, and advances in ancillary imaging techniques, biliary cannulation in endoscopic retrograde cholan...Despite improvements in endoscopic technologies and accessories, development of advanced endoscopy fellowship programs, and advances in ancillary imaging techniques, biliary cannulation in endoscopic retrograde cholangiopancreatography(ERCP) can still be unsuccessful in up to 20% of patients, even in referral centers. Once cannulation has been deemed to be difficult, the risk of post-ERCP pancreatitis and technical failure inherently increases. A number of factors, including endoscopist experience and patient anatomy, have been associated with difficult biliary cannulation, but predicting a case of difficult cannulation a priori is often not possible. Numerous techniques such as pancreatic guidewire and stenting, early pre-cut, and rendezvous may be employed when standard approaches fail. Data regarding the rate of success and adverse events of these techniques have been variable, though most studies suggest that pancreatic duct stenting generally reduces the rate of post-ERCP pancreatitis in instances of difficult biliary cannulation. Here we provide a review on difficult biliary cannulation and discuss how the choice of which techniques to employ and how to best employ them should be individualized and take into account the skill of the endoscopist, the disorder being treated, the anatomy of the patient, and the available biomedical literature.展开更多
This paper considers the problem of angles-only relative navigation for autonomous rendezvous. Methods for determining degree of observability （DO0） and latent range information of orbital maneuver are proposed for ...This paper considers the problem of angles-only relative navigation for autonomous rendezvous. Methods for determining degree of observability （DO0） and latent range information of orbital maneuver are proposed for analyzing and enhancing the precision of relative position and velocity estimation. The equations of angles-only relative navigation are set forth on the con- dition that optical camera is the only viable sensor for relative measurement, and expressions for the DO0 of relative navigation are obtained by using the Newton iterative method. The latent range information of orbital maneuver is analyzed, which is employed to enhance the DOO of angles-only relative navigation. Simulation result shows that DOO is effective to describe the observability level of relative position and velocity, and the latent range information is useful in enhancing the DOO of the angles-only relative navigation.展开更多
文摘Gallstone disease and complications from gallstones are a common clinical problem.The clinical presentation ranges between being asymptomatic and recurrent attacks of biliary pain requiring elective or emergency treatment.Bile duct stones are a frequent condition associated with cholelithiasis.Amidst the total cholecystectomies performed every year for cholelithiasis,the presence of bile duct stones is 5%-15%;another small percentage of these will develop common bile duct stones after intervention.To avoid serious complications that can occur in choledocholithiasis,these stones should be removed.Unfortunately,there is no consensus on the ideal management strategy to perform such.For a long time,a direct open surgical approach to the bile duct was the only unique approach.With the advent of advanced endoscopic,radiologic,and minimally invasive surgical techniques,however,therapeutic choices have increased in number,and the management of this pathological situation has become multidisciplinary.To date,there is agreement on preoperative management and the need to treat cholelithiasis with choledocholithiasis,but a debate still exists on how to cure the two diseases at the same time.In the era of laparoscopy and miniinvasiveness,we can say that therapeutic approaches can be performed in two sessions or in one session.Comparison of these two approaches showed equivalent success rates,postoperative morbidity,stone clearance,mortality,conversion to other procedures,total surgery time,and failure rate,but the onesession treatment is characterized by a shorter hospital stay,and more cost benefits.The aim of this review article is to provide the reader with a general summary of gallbladder stone disease in association with the presence of common bile duct stones by discussing their epidemiology,clinical and diagnostic aspects,and possible treatments and their advantages and limitations.
文摘Gallstones and common bile duct calculi are found to be associated in 8%-20% of patients, leading to possible life-threatening complications, such as acute biliary pancreatitis, jaundice and cholangitis. The gold standard of care for gallbladder calculi and isolated common bile duct stones is represented by laparoscopic cholecystectomy and endoscopic retrograde cholangiopancreatography, respectively, while a debate still exists regarding how to treat the two diseases at the same time. Many therapeutic options are also available when the two conditions are associated, including many different types of treatment, which local professionals often administer. The need to limit maximum discomfort and risks for the patients, combined with the economic pressure of reducing costs and utilizing resources, favors single-step procedures. However, a multitude of data fail to strongly demonstrate the superiority of any technique(including a two or multi-step approach), while rigorous clinical trials that include so many different types of treatment are still lacking, and it is most likely unrealistic to conduct them in the future. Therefore, the choice of the best management is often led by the local presence of professional expertise and resources, rather than by a real superiority of one strategy over another.
基金this work is supported in part by the National Postdoctoral Program for Innovative Talents(No.BX201700304)the Foundation of Science and Technology on Aerospace Flight Dynamics Laboratory(No.61422100306707).
文摘This research furthers the development of a closed-form solution to the angles-only initial relative orbit determination problem for non-cooperative target close-in proximity operations when the camera offset from the vehicle center-of-mass allows for range observability.In previous work,the solution to this problem had been shown to be non-global optimal in the sense of least square and had only been discussed in the context of Clohessy–Wiltshire.In this paper,the emphasis is placed on developing a more compact and improved solution to the problem by using state augmentation least square method in the context of the Clohessy–Wiltshire and Tschauner–Hempel dynamics,derivation of corresponding error covariance,and performance analysis for typical rendezvous missions.A two-body Monte Carlo simulation system is used to evaluate the performance of the solution.The sensitivity of the solution accuracy to camera offset,observation period,and the number of observations are presented and discussed.
基金co-supported by the National Natural Science Foundation of China (Nos.10902121 and 11222215)National Basic Research Program of China (No.2013CB733100)the Foundation for the Author of National Excellent Doctoral Dissertation of China (No.201171)
文摘Rendezvous orbital dynamics and control （RODC） is a key technology for operating space rendezvous and docking missions. This paper surveys the studies on RODC. Firstly, the basic relative dynamics equation set is introduced and its improved versions are evaluated. Secondly, studies on rendezvous trajectory optimization are commented from three aspects： the linear rendez- vous, the nonlinear two-body rendezvous, and the perturbed and constrained rendezvous. Thirdly, studies on relative navigation are briefly reviewed, and then close-range control methods including automated control, manual control, and telecontrol are analyzed. Fourthly, advances in rendezvous trajectory safety and robust analysis are surveyed, and their applications in trajectory optimization are discussed. Finally, conclusions are drawn and prospects of studies on RODC are presented.
文摘AIM: To investigate our clinical experience with combined laparo-endoscopic Rendezvous (RV) for the treatment of patients affected by gallstones and common bile duct (CBD) stones and especially to study the never evaluated opinion of the endoscopist concerning the difficulty of the intraoperative endoscopic procedure during the RV in comparison with standard endoscopic retrograde cholangio-pancreatography (ERCP). METHODS: Eighty consecutive patients affected by cholecystolithiasis and diagnosed or suspected CBD stones were treated with a standardized "tailored" RV. The relevant technical features, the feasibility, the effectiveness in stone clearance, the safety but also the simple evaluation of difficulty and agreement of the endoscopist were analyzed with a questionnaire. RESULTS: The feasibility was 97.5% and the effectiveness 100% concerning CBD clearance and solution of coexisting problems at the papilla. Minor morbidity was 3.3%, the operating time was prolonged by a mean of 14 min, the mean hospital stay was 3.8 d and only one stone’s recurrence occurred. The endoscopist evaluated the procedure to be simpler than standard ERCP-ES in 81.2% of the cases.CONCLUSION: Simultaneous RV carries higheffectiveness and safety at least comparable to those reported for other options. The endoscopist is very often satisfied with this approach because of the minimization of some steps of the endoscopic procedure and avoidance of relevant iatrogenic risk factors. If the mandatory collaboration between surgeons and endoscopists is guaranteed, this approach can often be preferable for the patient, the surgeon, the endoscopist and the hospital.
文摘 In the treatment of patients with symptomatic cholelithiasis and choledocholithiasis (CBDS) detected during intraoperative cholangiography (IOC),or when the preoperative study of a patient at intermediate risk for CBDS cannot be completed due to the lack of imaging techniques required for confirmation,or if they are available and yield contradictory radiological and clinical results,patients can be treated using intraoperative endoscopic retrograde cholangiopancreatography (ERCP) during the laparoscopic treatment or postoperative ERCP if the IOC finds CBDS.The choice of treatment depends on the level of experience and availability of each option at each hospital.Intraoperative ERCP has the advantage of being a single-stage treatment and has a significant success rate,an easy learning curve,low morbidity involving a shorter hospital stay and lower costs than the two-stage treatments (postoperative and preoperative ERCP).Intraoperative ERCP is also a good salvage treatment when preoperative ERCP fails or when total laparoscopic management also fails.
文摘Despite improvements in endoscopic technologies and accessories, development of advanced endoscopy fellowship programs, and advances in ancillary imaging techniques, biliary cannulation in endoscopic retrograde cholangiopancreatography(ERCP) can still be unsuccessful in up to 20% of patients, even in referral centers. Once cannulation has been deemed to be difficult, the risk of post-ERCP pancreatitis and technical failure inherently increases. A number of factors, including endoscopist experience and patient anatomy, have been associated with difficult biliary cannulation, but predicting a case of difficult cannulation a priori is often not possible. Numerous techniques such as pancreatic guidewire and stenting, early pre-cut, and rendezvous may be employed when standard approaches fail. Data regarding the rate of success and adverse events of these techniques have been variable, though most studies suggest that pancreatic duct stenting generally reduces the rate of post-ERCP pancreatitis in instances of difficult biliary cannulation. Here we provide a review on difficult biliary cannulation and discuss how the choice of which techniques to employ and how to best employ them should be individualized and take into account the skill of the endoscopist, the disorder being treated, the anatomy of the patient, and the available biomedical literature.
基金supported by the National Natural Science Foundation of China (Grant No. 10902101)
文摘This paper considers the problem of angles-only relative navigation for autonomous rendezvous. Methods for determining degree of observability （DO0） and latent range information of orbital maneuver are proposed for analyzing and enhancing the precision of relative position and velocity estimation. The equations of angles-only relative navigation are set forth on the con- dition that optical camera is the only viable sensor for relative measurement, and expressions for the DO0 of relative navigation are obtained by using the Newton iterative method. The latent range information of orbital maneuver is analyzed, which is employed to enhance the DOO of angles-only relative navigation. Simulation result shows that DOO is effective to describe the observability level of relative position and velocity, and the latent range information is useful in enhancing the DOO of the angles-only relative navigation.
