Endoscopy is widely accepted as the first treatment option in the management of bile duct stones.In this review we focus on the alternative endoscopic modalities for the management of difficult common bile duct stones...Endoscopy is widely accepted as the first treatment option in the management of bile duct stones.In this review we focus on the alternative endoscopic modalities for the management of difficult common bile duct stones.Most biliary stones can be removed with an extraction balloon,extraction basket or mechanical lithotripsy after endoscopic sphincterotomy.Endoscopic papillary balloon dilation with or without endoscopic sphincterotomy or mechanical lithotripsy has been shown to be effective for management of difficult to remove bile duct stones in selected patients.Ductal clearance can be safely achieved with peroral cholangioscopy guided laser or electrohydraulic lithotripsy in most cases where other endoscopic treatment modalities have failed.Biliary stenting may be an alternative treatment option for frail and elderly patients or those with serious co morbidities.展开更多
Due to the need for improvement in the diagnosis and minimally invasive therapy of the bile duct disorders new technologies for cholangioscopy have been recently developed. Per-oral cholangioscopy has become an import...Due to the need for improvement in the diagnosis and minimally invasive therapy of the bile duct disorders new technologies for cholangioscopy have been recently developed. Per-oral cholangioscopy has become an important diagnostic and therapeutic tool leading to avoidance of aggressive and unnecessary surgery in many clinical scenarios. This paper focuses on the newly developed SpyGlass DS technology, its advantages, and the technique of single-operator cholangioscopy(SOC), biliary indications and possible adverse events. We also review the available literature; discuss the limitations and future expectations.Digital SOC(D-SOC) is a useful technique, which provides endoscopic imaging of the biliary tree, optical diagnosis, biopsy under direct vision and therapeutic interventions. The implementations are diagnostic and therapeutic. Diagnostic indications are indeterminate biliary strictures, unclear filling defects, staging of cholangiocarcinoma, staging of ampullary tumors(extension into the common bile duct), unclear bile duct dilation, exploring cystic lesions of the biliary tree,unexplained hemobilia, posttransplant biliary complications. Therapeutic indications are lithotripsy of difficult stones, retrieval of migrated stents, foreign body removal, guide wire placement, transpapillary gallbladder drainage and endoscopic tumor ablative therapy. Most studied and established indications are the diagnosis of indeterminate biliary stricture and intraductal lithotripsy of difficult stones. The adverse events are not different and more common compared to those of Endoscopic retrograde cholangiopancreatography(ERCP)alone. D-SOC is a safe and effective procedure, adjunct to the standard ERCP and the newly available digital technology overcomes many of the limitations of the previous generations of cholangioscopes.展开更多
AIM: To assess the utility and safety of single-operator cholangiopancreatoscopy(SOCPS) using the Spy Glass system in widespread clinical application for biliary and pancreatic diseases.METHODS: This study was a prosp...AIM: To assess the utility and safety of single-operator cholangiopancreatoscopy(SOCPS) using the Spy Glass system in widespread clinical application for biliary and pancreatic diseases.METHODS: This study was a prospective case series conducted in 20 referral centers in Japan. There were 148 patients who underwent SOCPS; 124 for biliary diseases and 24 for pancreatic diseases. The attempted interventions were SOCPS examination, SOCPS-directed tissue sampling, and therapy for stone removal, among others. The main outcomes were related to the procedure success rate in terms of visualizing the target lesions, SOCPS-directed adequate tissue sampling, and complete stone removal. RESULTS: A total of 148 patients were enrolled for the diagnosis of indeterminate biliary and pancreatic lesions or treatment of biliary and pancreatic disease. The overall procedure success rate of visualizing the target lesions was 91.2%(135/148). The overall procedural success rates of visualizing the target lesions of diagnostic SOCPS in the bile duct and pancreatic duct were 95.5%(84/89) and 88.2%(15/17), respectively. Diagnosis: the overall adequate tissue for histologic examination was secured in 81.4% of the 86 patients who underwent biopsy under SOCPS(bile duct, 60/75, 80.0%; pancreatic duct, 10/11, 90.9%). The accuracy of histologic diagnosis using SOCPS-directed biopsies in indeterminate bile duct lesions was 70.7%(53/75). In the pancreatic duct, the accuracy of SOCPS visual impression of intraductal papillary mucinous neoplasm was 87.5%(14/16). Stone therapy: complete biliary and pancreatic stone clearance combined with SOCPS-directed stone therapy using electrohydraulic lithotripsy or laser lithotripsy was achieved in 74.2%(23/31) and 42.9%(3/7) of the patients, respectively. Others: SOCPS using the Spy Glass system was used in cannulation of the cystic duct in two patients and for passing across the obstructed self-expandable metallic stent for a malignant biliary stricture in two patients. All procedures were successful in both展开更多
Liver transplantation is the current standard of care for end-stage liver disease and an accepted therapeutic option for acute liver failure and primary liver tumors.Despite the remarkable advances in the surgical tec...Liver transplantation is the current standard of care for end-stage liver disease and an accepted therapeutic option for acute liver failure and primary liver tumors.Despite the remarkable advances in the surgical techniques and immunosuppressive therapy,the postoperative morbidity and mortality still remain high and the leading causes are biliary complications,which affect up to one quarter of recipients.The most common biliary complications are anastomotic and non-anastomotic biliary strictures,leaks,bile duct stones,sludge and casts.Despite the absence of a recommended treatment algorithm many options are available,such as surgery,percutaneous techniques and interventional endoscopy.In the last few years,endoscopic techniques have widely replaced the more aggressive percutaneous and surgical approaches.Endoscopic retrograde cholangiography is the preferred technique when duct-to-duct anastomosis has been performed.Recently,new devices and techniques have been developed and this has led to a remarkable increase in the success rate of minimally invasive procedures.Understanding the mechanisms of biliary complications helps in their early recognition which is the prerequisite for successful treatment.Aggressive endoscopic therapy is essential for the reduction of morbidity and mortality in these cases.This article focuses on the common post-transplant biliary complications and the available interventional treatment modalities.展开更多
Cholangiocarcinoma is a rare malignancy of the biliary tract. Key factors in determining therapeutic options include knowledge of tumor extent, anatomy and obtaining tissue diagnosis. Endoscopically, there are three m...Cholangiocarcinoma is a rare malignancy of the biliary tract. Key factors in determining therapeutic options include knowledge of tumor extent, anatomy and obtaining tissue diagnosis. Endoscopically, there are three modalities available to make the diagnosis of cholangiocarcinoma. These include endoscopic retrograde cholangiopancreatography, endoscopic ultrasound with fine needle aspiration and cholangioscopy. Management of cholangiocarcinoma endoscopically is typically confined to stent placement for palliative purposes or as a bridge to surgery. In this article, we will review the endoscopic techniques available for the diagnosis and management of cholangiocarcinoma.展开更多
Biliary strictures present a diagnostic challenge,especially when no etiology can be ascertained after laboratory evaluation,abdominal imaging and endoscopic retrograde cholangiopancreatography(ERCP)sampling.These str...Biliary strictures present a diagnostic challenge,especially when no etiology can be ascertained after laboratory evaluation,abdominal imaging and endoscopic retrograde cholangiopancreatography(ERCP)sampling.These strictures were traditionally classified as indeterminate strictures,although with advances in endoscopic techniques and better understanding of hepato-biliary pathology,more are being correctly diagnosed.The implications of missing a malignancy in patients with biliary strictures—and hence delaying surgery—are grave but a significant number of patients(up to 20%)undergoing surgery for suspected biliary malignancy can have benign pathology.The diagnostic approach to these patients involves detailed history and physical examination and depends on the presence or absence of jaundice,level of obstruction,and presence or absence of a mass lesion.While abdominal imaging helps to find the level of obstruction and provides a‘road map’for further endoscopic investigations,tissue diagnosis is usually needed to make decisions on management.Initially ERCP was the only modality to investigate these strictures but now,with the development of endoscopic ultrasound with fine needle aspiration and the availability of newer techniques such as intraductal ultrasound,single-operator cholangioscopy and confocal laser endomicroscopy,the diagnostic approach to biliary strictures has changed significantly.In this review,we will focus on the decision-making process for patients with biliary strictures and discuss the key decision points that should dictate further diagnostic investigations at each step.展开更多
Peroral cholangioscopy was first described in 1970s and has recently gained popularity.Peroral cholangioscopy is appealing to therapeutic endoscopists because a direct intraluminal view of the biliary duct system offe...Peroral cholangioscopy was first described in 1970s and has recently gained popularity.Peroral cholangioscopy is appealing to therapeutic endoscopists because a direct intraluminal view of the biliary duct system offers possibilities for diagnosis and interventions beyond that which other imaging or endoscopic modalities can provide.As the image quality of cholangioscopies improves,so too does their diagnostic capability,and as their durability and maneuverability increases,so too does their potential use for therapeutic applications.This editorial is intended to provide a brief review of recent developments in peroral cholangioscopy and current indications for its use.展开更多
Bile duct epithelial tumours showing papillary neoplasm in the bile duct lumen are present in the intrahepatic and extrahepatic bile ducts.Clinicopathological images of these tumours are distinctive and diverse,includ...Bile duct epithelial tumours showing papillary neoplasm in the bile duct lumen are present in the intrahepatic and extrahepatic bile ducts.Clinicopathological images of these tumours are distinctive and diverse,including histological images with a low to high grade dysplasia,infiltrating and noninfiltrating characteristics,excessive mucus production,and similarity to intraductal papillary mucinous neoplasm(IPMN)of the pancreas.The World Health Organization Classification of Tumours of the Digestive System in 2010 named these features,intraductal papillary neoplasm of the bile duct(IPNB),as precancerous lesion of biliary carcinoma.IPNB is currently classified into type 1 that is similar to IPMN,and type 2 that is not similar to IPMN.Many of IPNB spreads superficially,and diagnosis with cholangioscopy is considered mandatory to identify accurate localization and progression.Prognosis of IPNB is said to be better than normal bile duct cancer.展开更多
AIM:To detect and manage residual common bile duct(CBD)stones using ultraslim endoscopic peroral cholangioscopy(POC)after a negative balloon-occluded cholangiography.METHODS:From March 2011 to December 2011,a cohort o...AIM:To detect and manage residual common bile duct(CBD)stones using ultraslim endoscopic peroral cholangioscopy(POC)after a negative balloon-occluded cholangiography.METHODS:From March 2011 to December 2011,a cohort of 22 patients with CBD stones who underwent both endoscopic retrograde cholangiography(ERC)and direct POC were prospectively enrolled in this study.Those patients who were younger than 20 years of age,pregnant,critically ill,or unable to provide informed consent for direct POC,as well as those with concomitant gallbladder stones or CBD with diameters less than 10 mm were excluded.Direct POC using an ultraslim endoscope with an overtube balloon-assisted technique was carried out immediately after a negative balloon-occluded cholangiography was obtained.RESULTS:The ultraslim endoscope was able to be advanced to the hepatic hilum or the intrahepatic bile duct(IHD)in 8 patients(36.4%),to the extrahepatic bile duct where the hilum could be visualized in 10 patients(45.5%),and to the distal CBD where the hilum could not be visualized in 4 patients(18.2%).The procedure time of the diagnostic POC was 8.2 ± 2.9 min(range,5-18 min).Residual CBD stones were found in 5(22.7%)of the patients.There was one residual stone each in 3 of the patients,three in 1 patient,and more than five in 1 patient.The diameter of the residual stones ranged from 2-5 mm.In 2 of the patients,the residual stones were successfully extracted using either a retrieval balloon catheter(n = 1)or a basket catheter(n = 1)under direct endoscopic control.In the remaining 3 patients,the residual stones were removed using an irrigation and suction method under direct endoscopic visualization.There were no serious procedure-related complications,such as bleeding,pancreatitis,biliary tract infection,or perforation,in this study.CONCLUSION:Direct POC using an ultraslim endoscope appears to be a useful tool for both detecting and treating residual CBD stones after conventional ERC.展开更多
Endoscopic management for difficult common bile duct(CBD)stones still presents a challenge for several reasons,including anatomic anomalies,patients’individual conditions and stone features.In recent years,variable m...Endoscopic management for difficult common bile duct(CBD)stones still presents a challenge for several reasons,including anatomic anomalies,patients’individual conditions and stone features.In recent years,variable methods have emerged that have attributed to higher stone removal success rates,reduced cost and lower adverse events.In this review,we outline a stepwise approach in CBD stone management.As first line therapy,endoscopic sphincterotomy and large balloon dilation are recommended,due to a 30%-50%reduction of the use of mechanical lithotripsy.On the other hand,cholangioscopy-assisted lithotripsy has been increasingly reported as an effective and safe alternative technique to mechanical lithotripsy but remains to be reserved in special settings due to limited large-scale evidence.As discussed,findings suggest that management needs to be tailored to the patient’s characteristics and anatomical conditions.Furthermore,we evaluate the management of CBD stones in various surgical altered anatomy(Billroth II,Roux-en-Y and Roux-en-Y gastric bypass).Moreover,we could conclude that cholangioscopy-assisted lithotripsy needs to be evaluated for primary use,rather than following a failed management option.In addition,we discuss the importance of dissecting other techniques,such as the primary use of interventional endoscopic ultrasound for the management of CBD stones when other techniques have failed.In conclusion,we recognize that endoscopic sphincterotomy and large balloon dilation,mechanical lithotripsy and intraductal lithotripsy substantiate an indication to the management of difficult CBD stones,but emerging techniques are in rapid evolution with encouraging results.展开更多
文摘Endoscopy is widely accepted as the first treatment option in the management of bile duct stones.In this review we focus on the alternative endoscopic modalities for the management of difficult common bile duct stones.Most biliary stones can be removed with an extraction balloon,extraction basket or mechanical lithotripsy after endoscopic sphincterotomy.Endoscopic papillary balloon dilation with or without endoscopic sphincterotomy or mechanical lithotripsy has been shown to be effective for management of difficult to remove bile duct stones in selected patients.Ductal clearance can be safely achieved with peroral cholangioscopy guided laser or electrohydraulic lithotripsy in most cases where other endoscopic treatment modalities have failed.Biliary stenting may be an alternative treatment option for frail and elderly patients or those with serious co morbidities.
文摘Due to the need for improvement in the diagnosis and minimally invasive therapy of the bile duct disorders new technologies for cholangioscopy have been recently developed. Per-oral cholangioscopy has become an important diagnostic and therapeutic tool leading to avoidance of aggressive and unnecessary surgery in many clinical scenarios. This paper focuses on the newly developed SpyGlass DS technology, its advantages, and the technique of single-operator cholangioscopy(SOC), biliary indications and possible adverse events. We also review the available literature; discuss the limitations and future expectations.Digital SOC(D-SOC) is a useful technique, which provides endoscopic imaging of the biliary tree, optical diagnosis, biopsy under direct vision and therapeutic interventions. The implementations are diagnostic and therapeutic. Diagnostic indications are indeterminate biliary strictures, unclear filling defects, staging of cholangiocarcinoma, staging of ampullary tumors(extension into the common bile duct), unclear bile duct dilation, exploring cystic lesions of the biliary tree,unexplained hemobilia, posttransplant biliary complications. Therapeutic indications are lithotripsy of difficult stones, retrieval of migrated stents, foreign body removal, guide wire placement, transpapillary gallbladder drainage and endoscopic tumor ablative therapy. Most studied and established indications are the diagnosis of indeterminate biliary stricture and intraductal lithotripsy of difficult stones. The adverse events are not different and more common compared to those of Endoscopic retrograde cholangiopancreatography(ERCP)alone. D-SOC is a safe and effective procedure, adjunct to the standard ERCP and the newly available digital technology overcomes many of the limitations of the previous generations of cholangioscopes.
文摘AIM: To assess the utility and safety of single-operator cholangiopancreatoscopy(SOCPS) using the Spy Glass system in widespread clinical application for biliary and pancreatic diseases.METHODS: This study was a prospective case series conducted in 20 referral centers in Japan. There were 148 patients who underwent SOCPS; 124 for biliary diseases and 24 for pancreatic diseases. The attempted interventions were SOCPS examination, SOCPS-directed tissue sampling, and therapy for stone removal, among others. The main outcomes were related to the procedure success rate in terms of visualizing the target lesions, SOCPS-directed adequate tissue sampling, and complete stone removal. RESULTS: A total of 148 patients were enrolled for the diagnosis of indeterminate biliary and pancreatic lesions or treatment of biliary and pancreatic disease. The overall procedure success rate of visualizing the target lesions was 91.2%(135/148). The overall procedural success rates of visualizing the target lesions of diagnostic SOCPS in the bile duct and pancreatic duct were 95.5%(84/89) and 88.2%(15/17), respectively. Diagnosis: the overall adequate tissue for histologic examination was secured in 81.4% of the 86 patients who underwent biopsy under SOCPS(bile duct, 60/75, 80.0%; pancreatic duct, 10/11, 90.9%). The accuracy of histologic diagnosis using SOCPS-directed biopsies in indeterminate bile duct lesions was 70.7%(53/75). In the pancreatic duct, the accuracy of SOCPS visual impression of intraductal papillary mucinous neoplasm was 87.5%(14/16). Stone therapy: complete biliary and pancreatic stone clearance combined with SOCPS-directed stone therapy using electrohydraulic lithotripsy or laser lithotripsy was achieved in 74.2%(23/31) and 42.9%(3/7) of the patients, respectively. Others: SOCPS using the Spy Glass system was used in cannulation of the cystic duct in two patients and for passing across the obstructed self-expandable metallic stent for a malignant biliary stricture in two patients. All procedures were successful in both
文摘Liver transplantation is the current standard of care for end-stage liver disease and an accepted therapeutic option for acute liver failure and primary liver tumors.Despite the remarkable advances in the surgical techniques and immunosuppressive therapy,the postoperative morbidity and mortality still remain high and the leading causes are biliary complications,which affect up to one quarter of recipients.The most common biliary complications are anastomotic and non-anastomotic biliary strictures,leaks,bile duct stones,sludge and casts.Despite the absence of a recommended treatment algorithm many options are available,such as surgery,percutaneous techniques and interventional endoscopy.In the last few years,endoscopic techniques have widely replaced the more aggressive percutaneous and surgical approaches.Endoscopic retrograde cholangiography is the preferred technique when duct-to-duct anastomosis has been performed.Recently,new devices and techniques have been developed and this has led to a remarkable increase in the success rate of minimally invasive procedures.Understanding the mechanisms of biliary complications helps in their early recognition which is the prerequisite for successful treatment.Aggressive endoscopic therapy is essential for the reduction of morbidity and mortality in these cases.This article focuses on the common post-transplant biliary complications and the available interventional treatment modalities.
文摘Cholangiocarcinoma is a rare malignancy of the biliary tract. Key factors in determining therapeutic options include knowledge of tumor extent, anatomy and obtaining tissue diagnosis. Endoscopically, there are three modalities available to make the diagnosis of cholangiocarcinoma. These include endoscopic retrograde cholangiopancreatography, endoscopic ultrasound with fine needle aspiration and cholangioscopy. Management of cholangiocarcinoma endoscopically is typically confined to stent placement for palliative purposes or as a bridge to surgery. In this article, we will review the endoscopic techniques available for the diagnosis and management of cholangiocarcinoma.
文摘Biliary strictures present a diagnostic challenge,especially when no etiology can be ascertained after laboratory evaluation,abdominal imaging and endoscopic retrograde cholangiopancreatography(ERCP)sampling.These strictures were traditionally classified as indeterminate strictures,although with advances in endoscopic techniques and better understanding of hepato-biliary pathology,more are being correctly diagnosed.The implications of missing a malignancy in patients with biliary strictures—and hence delaying surgery—are grave but a significant number of patients(up to 20%)undergoing surgery for suspected biliary malignancy can have benign pathology.The diagnostic approach to these patients involves detailed history and physical examination and depends on the presence or absence of jaundice,level of obstruction,and presence or absence of a mass lesion.While abdominal imaging helps to find the level of obstruction and provides a‘road map’for further endoscopic investigations,tissue diagnosis is usually needed to make decisions on management.Initially ERCP was the only modality to investigate these strictures but now,with the development of endoscopic ultrasound with fine needle aspiration and the availability of newer techniques such as intraductal ultrasound,single-operator cholangioscopy and confocal laser endomicroscopy,the diagnostic approach to biliary strictures has changed significantly.In this review,we will focus on the decision-making process for patients with biliary strictures and discuss the key decision points that should dictate further diagnostic investigations at each step.
文摘Peroral cholangioscopy was first described in 1970s and has recently gained popularity.Peroral cholangioscopy is appealing to therapeutic endoscopists because a direct intraluminal view of the biliary duct system offers possibilities for diagnosis and interventions beyond that which other imaging or endoscopic modalities can provide.As the image quality of cholangioscopies improves,so too does their diagnostic capability,and as their durability and maneuverability increases,so too does their potential use for therapeutic applications.This editorial is intended to provide a brief review of recent developments in peroral cholangioscopy and current indications for its use.
文摘Bile duct epithelial tumours showing papillary neoplasm in the bile duct lumen are present in the intrahepatic and extrahepatic bile ducts.Clinicopathological images of these tumours are distinctive and diverse,including histological images with a low to high grade dysplasia,infiltrating and noninfiltrating characteristics,excessive mucus production,and similarity to intraductal papillary mucinous neoplasm(IPMN)of the pancreas.The World Health Organization Classification of Tumours of the Digestive System in 2010 named these features,intraductal papillary neoplasm of the bile duct(IPNB),as precancerous lesion of biliary carcinoma.IPNB is currently classified into type 1 that is similar to IPMN,and type 2 that is not similar to IPMN.Many of IPNB spreads superficially,and diagnosis with cholangioscopy is considered mandatory to identify accurate localization and progression.Prognosis of IPNB is said to be better than normal bile duct cancer.
基金Supported by Chang Gung Memorial Hospital,No. CMRPG300011
文摘AIM:To detect and manage residual common bile duct(CBD)stones using ultraslim endoscopic peroral cholangioscopy(POC)after a negative balloon-occluded cholangiography.METHODS:From March 2011 to December 2011,a cohort of 22 patients with CBD stones who underwent both endoscopic retrograde cholangiography(ERC)and direct POC were prospectively enrolled in this study.Those patients who were younger than 20 years of age,pregnant,critically ill,or unable to provide informed consent for direct POC,as well as those with concomitant gallbladder stones or CBD with diameters less than 10 mm were excluded.Direct POC using an ultraslim endoscope with an overtube balloon-assisted technique was carried out immediately after a negative balloon-occluded cholangiography was obtained.RESULTS:The ultraslim endoscope was able to be advanced to the hepatic hilum or the intrahepatic bile duct(IHD)in 8 patients(36.4%),to the extrahepatic bile duct where the hilum could be visualized in 10 patients(45.5%),and to the distal CBD where the hilum could not be visualized in 4 patients(18.2%).The procedure time of the diagnostic POC was 8.2 ± 2.9 min(range,5-18 min).Residual CBD stones were found in 5(22.7%)of the patients.There was one residual stone each in 3 of the patients,three in 1 patient,and more than five in 1 patient.The diameter of the residual stones ranged from 2-5 mm.In 2 of the patients,the residual stones were successfully extracted using either a retrieval balloon catheter(n = 1)or a basket catheter(n = 1)under direct endoscopic control.In the remaining 3 patients,the residual stones were removed using an irrigation and suction method under direct endoscopic visualization.There were no serious procedure-related complications,such as bleeding,pancreatitis,biliary tract infection,or perforation,in this study.CONCLUSION:Direct POC using an ultraslim endoscope appears to be a useful tool for both detecting and treating residual CBD stones after conventional ERC.
文摘Endoscopic management for difficult common bile duct(CBD)stones still presents a challenge for several reasons,including anatomic anomalies,patients’individual conditions and stone features.In recent years,variable methods have emerged that have attributed to higher stone removal success rates,reduced cost and lower adverse events.In this review,we outline a stepwise approach in CBD stone management.As first line therapy,endoscopic sphincterotomy and large balloon dilation are recommended,due to a 30%-50%reduction of the use of mechanical lithotripsy.On the other hand,cholangioscopy-assisted lithotripsy has been increasingly reported as an effective and safe alternative technique to mechanical lithotripsy but remains to be reserved in special settings due to limited large-scale evidence.As discussed,findings suggest that management needs to be tailored to the patient’s characteristics and anatomical conditions.Furthermore,we evaluate the management of CBD stones in various surgical altered anatomy(Billroth II,Roux-en-Y and Roux-en-Y gastric bypass).Moreover,we could conclude that cholangioscopy-assisted lithotripsy needs to be evaluated for primary use,rather than following a failed management option.In addition,we discuss the importance of dissecting other techniques,such as the primary use of interventional endoscopic ultrasound for the management of CBD stones when other techniques have failed.In conclusion,we recognize that endoscopic sphincterotomy and large balloon dilation,mechanical lithotripsy and intraductal lithotripsy substantiate an indication to the management of difficult CBD stones,but emerging techniques are in rapid evolution with encouraging results.