AIM： To describe characteristics of a poorly expandable （PE） common bile duct （CBD） with stones on en- doscopic retrograde cholangiography.METHODS： APE bile duct was characterized by a rigid and relatively narro...AIM： To describe characteristics of a poorly expandable （PE） common bile duct （CBD） with stones on en- doscopic retrograde cholangiography.METHODS： APE bile duct was characterized by a rigid and relatively narrowed distal CBD with retro- grade dilatation of the non-PE segment. Between 2003 and 2006, endoscopic retrograde cholangiography （ERC） images and chart reviews of 1213 patients with newly diagnosed CBD stones were obtained from the computer database of Therapeutic Endoscopic Centerin Chang Gung Memoria acteristic PE bile duct on Hospital. Patients with char ERC were identified from the database. Data of the patients as well as the safety and technical success of therapeutic ERC were collected and analyzed retrospectively.RESULTS： A total of 30 patients with CBD stones and characteristic PE segments were enrolled in this study. The median patient age was 45 years （range, 20 to 92 years）; 66.7% of the patients were men. The di ameters of the widest non-PE CBD segment, the PE segment, and the largest stone were 14.3 ± 4.9 mm, 5.8±1.6 mm, and 11.2±4.7 mm, respectively. The length of the PE segment was 39.7±15.4 mm （range, 12.3 mm to 70.9 mm）. To remove the CBD stone（s） completely, mechanical lithotripsy was required in 25 （83.3%） patients even though the stone size was not as large as were the difficult stones that have been described in the literature. The stone size and stone/ PE segment diameter ratio were associated with the need for lithotripsy. Post-ERC complications occurred in 4 cases： pancreatitis in 1, cholangitis in 2, and an im- pacted Dormia basket with cholangitis in 1. Two （6.7%） of the 28 patients developed recurrent CBD stones at follow-up （50±14 mo） and were successfully managed with therapeutic ERC.CONCLUSION： Patients with a PE duct frequently require mechanical lithotripsy for stones extraction, To retrieve stones successfully and avoid complications, these patients should be identified during ERC,展开更多
The determination of the gravitational potential of a prism plays an important role in physical geodesy and geophysics. However, there are few literatures that provide accurate approaches for determining the gravitati...The determination of the gravitational potential of a prism plays an important role in physical geodesy and geophysics. However, there are few literatures that provide accurate approaches for determining the gravitational potential of a prism. Discrete element method can be used to determine the gravitational potential of a prism, and can approximate the true gravitational potential values with sufficient accuracy (the smaller each element is, the more accurate the result is). Although Nagy's approach provided a closed expression, one does not know whether it is valid, due to the fact that this approach has not been confirmed in literatures. In this paper, a study on the comparison of Nagy's approach with discrete element method is presented. The results show that Nagy's formulas for determining the gravitational potential of a prism are valid in the domain both inside and outside the prism.展开更多
文摘AIM： To describe characteristics of a poorly expandable （PE） common bile duct （CBD） with stones on en- doscopic retrograde cholangiography.METHODS： APE bile duct was characterized by a rigid and relatively narrowed distal CBD with retro- grade dilatation of the non-PE segment. Between 2003 and 2006, endoscopic retrograde cholangiography （ERC） images and chart reviews of 1213 patients with newly diagnosed CBD stones were obtained from the computer database of Therapeutic Endoscopic Centerin Chang Gung Memoria acteristic PE bile duct on Hospital. Patients with char ERC were identified from the database. Data of the patients as well as the safety and technical success of therapeutic ERC were collected and analyzed retrospectively.RESULTS： A total of 30 patients with CBD stones and characteristic PE segments were enrolled in this study. The median patient age was 45 years （range, 20 to 92 years）; 66.7% of the patients were men. The di ameters of the widest non-PE CBD segment, the PE segment, and the largest stone were 14.3 ± 4.9 mm, 5.8±1.6 mm, and 11.2±4.7 mm, respectively. The length of the PE segment was 39.7±15.4 mm （range, 12.3 mm to 70.9 mm）. To remove the CBD stone（s） completely, mechanical lithotripsy was required in 25 （83.3%） patients even though the stone size was not as large as were the difficult stones that have been described in the literature. The stone size and stone/ PE segment diameter ratio were associated with the need for lithotripsy. Post-ERC complications occurred in 4 cases： pancreatitis in 1, cholangitis in 2, and an im- pacted Dormia basket with cholangitis in 1. Two （6.7%） of the 28 patients developed recurrent CBD stones at follow-up （50±14 mo） and were successfully managed with therapeutic ERC.CONCLUSION： Patients with a PE duct frequently require mechanical lithotripsy for stones extraction, To retrieve stones successfully and avoid complications, these patients should be identified during ERC,
基金Supported by the National Natural Science Foundation of China (No.40637034, 40974015)the National 863 Program of China (No.2006AA12Z211)
文摘The determination of the gravitational potential of a prism plays an important role in physical geodesy and geophysics. However, there are few literatures that provide accurate approaches for determining the gravitational potential of a prism. Discrete element method can be used to determine the gravitational potential of a prism, and can approximate the true gravitational potential values with sufficient accuracy (the smaller each element is, the more accurate the result is). Although Nagy's approach provided a closed expression, one does not know whether it is valid, due to the fact that this approach has not been confirmed in literatures. In this paper, a study on the comparison of Nagy's approach with discrete element method is presented. The results show that Nagy's formulas for determining the gravitational potential of a prism are valid in the domain both inside and outside the prism.
