Percutaneous Transhepatic Cholangioscopy Research Articles

Percutaneous transhepatic cholangioscopy-assisted biliary polypectomy for local palliative treatment of intraductal papillary neoplasm of the bile duct.

Intraductal papillary neoplasm of the bile duct (IPNB) is a premalignant biliary-type epithelial neoplasm with intraductal papillary or villous growth. Currently reported local palliative therapeutic modalities, including endoscopic nasobiliary drainage, stenting and biliary curettage, endoscopic biliary polypectomy, percutaneous biliary drainage, laser ablation, argon plasma coagulation, photodynamic therapy, and radiofrequency ablation to relieve mechanical obstruction are limited with weaknesses and disadvantages. We have applied percutaneous transhepatic cholangioscopy (PTCS)-assisted biliary polypectomy (PTCS-BP) technique for the management of IPNB including mucin-hypersecreting cast-like and polypoid type tumors since 2010. To assess the technical feasibility, efficacy, and safety of PTCS-BP for local palliative treatment of IPNB. Patients with mucin-hypersecreting cast-like or polypoid type IPNB and receiving PTCS-BP between September 2010 and December 2019 were included. PTCS-BP was performed by using a half-moon type snare with a soft stainless-steel wire, and the tumor was snared and resected with electrocautery. The primary outcome was its feasibility, indicated by technical success. The secondary outcomes were efficacy, including therapeutic success, curative resection, and clinical success, and safety. Five patients (four with mucin-hypersecreting cast-like type and one with polypoid type IPNB) were included. Low- and high-grade intraepithelial neoplasia (HGIN) and recurrent IPNB with invasive carcinoma were observed in one, two, and two patients, respectively. Repeated cholangitis and/or obstructive jaundice were presented in all four patients with mucin-hypersecreting cast-like type IPNB. All five patients achieved technical success of PTCS-BP. Four patients (three with mucin-hypersecreting cast-like type and one with polypoid type IPNB) obtained therapeutic success; one with mucin-hypersecreting cast-like type tumors in the intrahepatic small bile duct and HGIN had residual tumors. All four patients with mucin-hypersecreting IPNB achieved clinical success. The patient with polypoid type IPNB achieved curative resection. There were no PTCS-BP-related serious adverse events. PTCS-BP appears to be feasible, efficacious, and safe for local palliative treatment of both mucin-hypersecreting cast-like and polypoid type IPNB.

Cholangioscopy with Spyglass DS using percutaneous transhepatic cholangiography access: a retrospective cohort study.

Conventional peroral methods to visualize biliary strictures are not feasible in some patients with altered anatomy or biliary obstruction, and percutaneous transhepatic cholangioscopy can be used as an alternative procedure. This study aimed to retrospectively review the use of percutaneous transhepatic cholangiography using the SpyGlass DS technology (S-PTCS) during a 5-year period at a Danish tertiary referral centre. All patients who underwent S-PTCS at a single Danish tertiary referral centre between 2016 and 2021 were retrospectively analyzed. The visual, technical, and overall success rates of S-PTCS were analyzed, as well as the complication rate. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of S-PTCS were calculated. Twenty-two patients were included in the study. Visual, technical, and overall success of S-PTCS was achieved in 17/22, 22/22, and 21/22 patients, respectively. S-PTCS yielded a sensitivity of 83.3%, a specificity of 100%, a PPV of 100%, a NPV of 94.1%, and an accuracy of 95.4%. Complications occurred in 1/22 patients. S-PTCS is a safe modality, with high success rates, high predictive values, and a low rate of complications. This study suggests that S-PTCS is an alternative to conventional methods in patients with indeterminate biliary strictures where conventional methods were unfeasible.

Management of anastomotic biliary stricture through utilizing percutaneous transhepatic cholangioscopy

Occurrence of anastomotic biliary stricture (AS) remains an essential issue following hepatobiliary surgeries, and percutaneous transhepatic cholangioscopy (PTCS) has great therapeutic significance in handling refractory AS for patients with altered gastrointestinal anatomy after cholangio-jejunostomy. This present study aimed to investigate feasibility of PTCS procedures in AS patients for therapeutic indications. This study was a single-center, retrospective cohort study with a total number of 124 consecutive patients who received therapeutic PTCS due to AS. Clinical success rate, required number, and adverse events of therapeutic PTCS procedures as well as patients survival state were reviewed. These 124 patients previously underwent choledochojejunostomy or hepatico-jejunostomy, and there was post-surgical altered gastrointestinal anatomy. Overall, 366 therapeutic PTCS procedures were performed for these patients through applying rigid choledochoscope, and the median time of PTCS procedures was 3 (1-11). Among these patients, there were 34 cases (27.32%) accompanied by biliary strictures and 100 cases (80.65%) were also combined with biliary calculi. After therapeutic PTCS, most patients presented with relieved clinical manifestations and improved liver functions. The median time of follow-up was 26 months (2-86 months), and AS was successfully managed through PTCS procedures in 104 patients (83.87%). During the follow-up period, adverse events occurred in 81 cases (65.32%), most of which were tackled through supportive treatment. PTCS was a feasible, safe and effective therapeutic modality for refractory AS, which may be a promising alternative approach in clinical cases where the gastrointestinal anatomy was changed after cholangio-jejunostomy.

Abstract No. 14 Efficacy of Percutaneous Transhepatic Cholangioscopy in Managing Bilio-enteric Complications in Patients with Prior Surgery

Abstract No. 14 Efficacy of Percutaneous Transhepatic Cholangioscopy in Managing Bilio-enteric Complications in Patients with Prior Surgery

Percutaneous Transhepatic Cholangioscopy Interventions-Updates.

Percutaneous transhepatic cholangioscopy (PTCS) was initially described around the same time that peroral cholangioscopy (POSC) was developed. The cited utility attributed to PTCS is the ability to be utilized in the subset of patients with surgical proximal bowel anatomy, often precluding the use of traditional POSC. However, since first described, PTCS use has been limited due to a lack of physician awareness and a lack of procedure-specific equipment and supplies. With recent developments of PTSC-specific equipment, there has been an expansion in the possible interventions able to be performed during PTCS, resulting in a rapid increase in clinical use. This short review will serve as a comprehensive update of the previous and more recent novel interventions now able to be performed during PTCS.

Advanced Biliary Interventions: Gastrointestinal or Interventional Radiology Approach

AbstractThe management of biliary pathology can be surgical, endoscopic, or percutaneous. Percutaneous interventions play an important role in the management of patients. Biliary drainage is the initial step in most radiological interventions, including percutaneous transhepatic cholangioscopy. It can be palliative or curative. We present here the different techniques available from interventional radiology. The purpose of this review article is to investigate the latest published evidence on percutaneous minimally invasive approach of biliary disease and outline current trends.

A Unique Approach to Obtaining Tissue in a Difficult to Access Indeterminate Biliary Stricture: Percutaneous Cholangioscopy and Biopsy

ABSTRACT When evaluating biliary strictures, establishing a diagnosis can present challenges. The first-line approach of endoscopic retrograde cholangiopancreatography can often involve anatomic restrictions. Traditionally, percutaneous transhepatic cholangioscopy has been the answer for biopsies unable to be obtained with the modalities above but requires time for large tract dilation and days of sinus tract maturation to allow for a scope. We present a novel case of percutaneous digital cholangioscopy with SpyGlass DS, a small caliber scope traditionally used with endoscopic retrograde cholangiopancreatography, used for percutaneous transhepatic cholangioscopy after previous failed attempts by several different standard methods. Our case highlights a multidisciplinary approach in ultimately diagnosing malignancy.

Safety and feasibility of a novel recanalization technique using guidewire puncture under cholangioscopy for complete biliary stricture after liver transplantation

Cholangioscopy is reportedly useful for selective guidewire placement across difficult biliary strictures, but few methods are available for complete stricture of biliary anastomosis. This study aimed to propose a guidewire puncture technique to recanalize totally obstructed anastomosis and discuss its safety and feasibility. From January 2015 to December 2021, a total of 11 patients with complete biliary anastomotic stricture after liver transplantation were enrolled. These patients underwent peroral single operator cholangioscopy (SpyGlass), whereas two failed cases on SpyGlass finally underwent percutaneous transhepatic cholangioscopy (PTCS). The steps of the recanalization technique were as follows: the stricture was viewed carefully to detect the closure point (CP) of the scar endoscopically, then the CP was targeted by the hard tip of the guidewire and broke through under guidance of the cholangioscope and fluoroscope. Complete occlusions were confirmed by SpyGlass in all cases. A total of 13 hard-tip guidewire punctures were performed under cholangioscopy, and ten punctures were successful (technical success rate, 76.9% [10/13]). After recanalization of the occluded anastomosis, plastic stent or metallic stent was deployed in three and seven patients, respectively. No procedure-related complications occurred during or after the cholangioscopy-assisted guidewire puncture. After a mean follow-up of 12 months, stents had been removed in five patients. The other six patients were still receiving stent treatment. This study demonstrated that the guidewire puncture technique under cholangioscopy is safe and feasible for complete stricture of biliary anastomosis, and the success rate is satisfactory.

Efficiency of percutaneous transhepatic cholangioscopy in the treatment of biliary complications after liver transplantation

BackgroundPercutaneous transhepatic cholangioscopy (PTCS) has provided an alternative therapeutic option for handling refractory biliary complications in liver transplanted recipients. This study aimed to evaluate short-term PTCS efficiency in the management of biliary complications following liver transplantation. MethodsClinical data of 25 patients who received therapeutic PTCS due to biliary complications after liver transplantation were retrospectively analyzed. ResultsTherapeutic PTCS was successfully performed in 25 patients. Biliary complications were anastomotic strictures in seven cases, intrahepatic cholangiolithiasis in four cases, extra-and intrahepatic cholangiolithiasis in three cases, choledocholithiasis complicated with anastomotic strictures in four cases, intrahepatic cholangiolithiasis complicated with non-anastomotic strictures in one case, intrahepatic cholangiolithiasis complicated with anastomotic strictures in five cases, intrahepatic cholangiolithiasis complicated with anastomotic strictures and ischemic cholangitis in one case. The median time between liver transplantation and first PTCS was 24 months, and median times of PTCS was 2.6. Clinical manifestations were significantly improved in most patients after PTCS, and biliary complications were successfully managed through PTCS in 15 cases, which were partially effective in eight cases and ineffective in two cases. PTCS was more effective in tackling anastomotic strictures and cholangiolithiasis. ConclusionPTCS was an effective therapeutic modality for treating refractory biliary complications following liver transplantation.

S64 A Case Series to Assess Effectiveness and Complications of Percutaneous Transhepatic Cholangioscopy With SpyglassTM Direct Visualization System in Individuals With Altered Gut Anatomy

S64 A Case Series to Assess Effectiveness and Complications of Percutaneous Transhepatic Cholangioscopy With SpyglassTM Direct Visualization System in Individuals With Altered Gut Anatomy

Long-term efficacy of percutaneous transhepatic cholangioscopy-guided photodynamic therapy for postoperative recurrent extrahepatic cholangiocarcinoma

BackgroundCholangiocarcinoma recurs frequently following excision surgery and is usually inoperable, while radiotherapy, chemotherapy, and immunotherapy are of limited benefit. As palliative care, percutaneous transhepatic cholangial drainage (PTCD) can relieve biliary obstruction, prevent jaundice, and maintain quality of life (QOL), but does not improve overall survival. In contrast, photodynamic therapy (PDT) has been demonstrated to prolong the survival of inoperable cancer patients. ObjectiveThis study evaluated the clinical efficacy of percutaneous transhepatic cholangioscopy (PTCS)-guided PDT following PTCD versus PTCD alone for recurrent inoperable cholangiocarcinoma. MethodsThe case files of 39 patients with postoperative recurrence were retrospectively analyzed, including 18 receiving PTCS-guided PDT (PTCS-PDT group) and 21 receiving PTCD only as a control (PTCD group). Survival time was compared by Kaplan-Meier analysis and log-rank test, and QOL by the Functional Assessment of Cancer Therapy–Hepatobiliary (FACT-HEP) questionnaire. Clinicodemographic factors, including serum bilirubin and adverse reaction rates, were compared by Student's t-test or Fisher's exact test. The maximum follow-up period was 71 months. ResultsMedian survival time was significantly longer in the PTCS-PDT group than the PTCD group (23 months vs. 10 months, P = 0.00001). At 6 and 12 months post-treatment, total FACT-HEP score was lower in the PTCS-PDT group (P < 0.05), indicating improved QOL. There was no significant difference in total adverse events incidence between groups (19 [51.4%] vs. 15 [71.4%]; P = 0.131). ConclusionPTCS-guided PDT can prolong survival and improve the QOL of patients with postoperative cholangiocarcinoma recurrence without increasing complications. Significant and/or new findingsCompared to PTCD alone, PTCS-guided PDT significantly prolonged the survival time of patients with postoperative recurrent extrahepatic cholangiocarcinoma. Photodynamic therapy also improved patient quality of life by facilitating timely removal of the PTCD drainage tube. PTCS-guided PDT did not increase surgery-related complications except for skin phototoxicity, which can be easy avoided and treated.

A Two-Step Method for Percutaneous Transhepatic Choledochoscopic Lithotomy.

Intrahepatic and extrahepatic choledocholithiasis is a challenge in the field of biliary surgery. We present our experience using a two-step percutaneous transhepatic choledochoscopic lithotomy (PTCSL) procedure to treat challenging biliary stones. We retrospectively reviewed 81 patients with intrahepatic and extrahepatic choledocholithiasis treated using this two-step PTCSL from January 2013 to January 2020, including 40 males and 41 females, with an average age of 66 years. In contrast to traditional percutaneous transhepatic cholangioscopy (PTCS), a channel was established directly through a 16F Amplatz sheath, and the stone in the channel was removed with the aid of a nephroscope. The clinical efficacy and complications of all patients were analyzed. Eighty-one patients (81/81, 100%) had their biliary stones successfully removed; 62/81 patients (76.5%) had biliary stones completely removed after the first operation; 17/81 patients (21%) underwent a second operation; 2/81 patients (2.5%) needed a third operation to completely remove the stones. The incidence of severe bleeding during the operation was 0%, and there were no deaths. The use of the two-step PTCSL method is safe and efficacious, and contributes to a better prognosis of intrahepatic and extrahepatic choledocholithiasis.

Intraoperative ultrasound-guided percutaneous hepatocholangiostomy applied in the cholangioscopic lithotripsy for hepatolithiasis and choledocholithiasis.

Percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) is a minimally invasive treatment for hepatolithiasis. But it may make a long cycle of treatment so that it was further improved to complete the percutaneous hepatic choledochotomy and choledochoscopic lithotripsy in phase I surgery. The aim of this study was to evaluate the efficacy of the modified technique comparing with laparoscopic choledochotomy. Retrospective analysis of the clinical data of patients with hepatolithiasis or choledocholithiasis consulted at our hospital from February 2018 to December 2021. The cases were divided into two groups according to surgical modality, intraoperative ultrasound-guided percutaneous transhepatic cholangioscopic lithotripsy (IUG-PTCSL) and laparoscopic choledochotomy lithotripsy (LC-L). Contrast analysis determined the advantages of the two approaches. IUG-PTCSL was performed in 44 patients, aged 58.14 ± 14.01years, including 9 male and 35 female. There were 15 patients underwent LC-L, aged 62.13 ± 15.03years, including 1 male and 14 female. There was not statistically significant difference in the composition of patients' age and sex between the two groups (p = 0.356, 0.219). The success rate of intraoperative ultrasound-guided percutaneous hepatic bile duct puncture was 100% followed with the success rate of hepatocholangiostomy was 100%. Although 1 (1/44) patient showed significant bleeding during choledochoscopic lithotripsy and was converted to open choledochotomy for stone extraction, 43 patients completed IUG-PTCSL with the rate of phase I surgical stones removal was 81.40% (35/43), whereas the stones removal rate of LC-L was 66.67% (10/15). There was not statistically significant difference between them (p = 0.067). Both the groups showed no significant complications with the postoperative hospital stay of 8 (6, 10) days and 10 (8, 11) days, respectively, and the difference was statistically significant (p = 0.028). Intraoperative ultrasound-guided percutaneous transhepatic cholangioscopy might be a safe and reliable ideal method for bile duct stones with the advantages of rapid recovery for patients. Intraoperative ultrasound-guided percutaneous hepatocholangiostomy may be the key technique for the successful completion of the surgery.

National Survey Regarding the Management of Difficult Bile Duct Stones in South Korea.

This study aimed to investigate the patterns of preferred endoscopic procedure types and techniques for managing difficult common bile duct (CBD) stones in South Korea. The Committee of Policy and Quality Management of Korean Pancreatobiliary Association (KPBA) conducted a survey containing 19 questions. Both paper and online surveys were carried out; with the paper survey being conducted during the 2019 Annual Congress of KPBA and the online survey being conducted through Google Forms from April 2020 to February 2021. The response rate was approximately 41.3% (86/208). Sixty-two (73.0%) worked at tertiary hospitals or academic medical centers, and 60 (69.7%) had more than 5 years of endoscopic retrograde cholangiopancreatography experience. The preferred size criteria for large CBD stones were 15 mm (40.6%), 20 mm (31.3%), and 30 mm (4.6%). For managing of large CBD stones, endoscopic papillary large balloon dilation after endoscopic sphincterotomy was the most preferred technique (74.4%). When performing procedures in those with bleeding diathesis, 64 (74.4%) respondents favored endoscopic papillary balloon dilation (EPBD) alone or EPBD with small endoscopic sphincterotomy. Fifty-five respondents (63.9%) preferred the doubleguidewire technique when faced with difficult bile duct cannulation in patients with periampullary diverticulum. In surgically altered anatomies, cap-fitted forward viewing endoscopy (76.7%) and percutaneous transhepatic cholangioscopy (48.8%) were the preferred techniques for Billroth-II anastomosis and total gastrectomy with Roux-en-Y anastomosis, respectively. Most respondents showed unifying trends for the management of difficult CBD stones. The current practice patterns could be used as basic data for clinical quality improvements in the management of difficult CBD stones.

Efficacy and Safety of Percutaneous Transhepatic Cholangioscopy with the Spyglass DS Direct Visualization System in Patients with Surgically Altered Anatomy: A Pilot Study

Background/AimsPercutaneous transhepatic cholangioscopy (PTCS) is used for the diagnosis and treatment of biliary diseases in patients with failed endoscopic retrograde cholangiopancreatography, particularly those with surgically altered anatomy. However, few studies are available on the clinical use of Spyglass DS direct visualization system (SpyDS)-assisted PTCS. This study aimed to assess the efficacy and safety of SpyDS-assisted PTCS in patients with surgically altered anatomy, particularly those with a Roux-en-Y reconstruction.MethodsThirteen patients (six women, median age 71.4 years [range, 53 to 83 years]) with surgically altered anatomy (four Roux-en-Y choledochojejunostomies, seven Roux-en-Y hepaticojejunostomies, and two Roux-en-Y esophagojejunostomies) who underwent SpyDS-assisted PTCS between January 2019 and August 2020 were included and the data was acquired by retrospectively reviewing electronic medical record.ResultsA total of 19 SpyDS-assisted PTCS procedures were performed in the 13 patients eight had bile-duct stones, and five had biliary strictures. All SpyDS-assisted PTCS procedures were successfully performed. The total procedure time was 42.42±18.0 minutes (mean±standard deviation). Bile duct clearance was achieved in all bile duct stone cases after a median of 2 (range, 1 to 3) procedures. In the five biliary stricture cases, the results of SpyBite forceps-guided targeted biopsy were consistent with adenocarcinoma (100% accuracy). The median hospitalization duration was 20 days (range, 14 to 30 days). No procedure-related morbidity or mortality occurred.ConclusionsSpyDS-assisted PTCS may be a safe, feasible, and effective procedure for the diagnosis and treatment of biliary diseases in patients with surgically altered anatomy, particularly in those with the Roux-en-Y reconstruction requiring a percutaneous approach. However, our findings need to be validated in further studies.

Endoscopic management of difficult common bile duct stones.

Common bile duct stones are a very frequent problem in the western world and endoscopic stone clearance is the method of choice for treatment. Despite its common use, endoscopic clearance of common bile duct stones is not always trivial especially in cases involving large or multiple stones. A literature review regarding different endoscopic techniques was performed for this article and a recommended therapeutic algorithm developed based on the guidelines of the European Society of Gastrointestinal Endoscopy and the German Gastroenterological Society. This review gives an overview of currently applied endoscopic techniques, their success and complication rates as well as alternative methods used for cases involving anatomic anomalies. The purpose of this review is to recommend a therapeutic algorithm for the treatment of difficult common bile duct stones (DCBDS). For the treatment of DCBDS, combined sphincterotomy and endoscopic large balloon dilation should be first choice. Mechanical lithotripsy and cholangioscopy-guided lithotripsy are close alternatives with nearly equal clearance rates and should be used if accessible. The insertion of a temporary plastic stent is a good choice to gain time to explore further treatment options. Enteroscopy-based endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangioscopy or endoscopic ultrasound-guided hepaticogastrostomy and stone treatment, while good alternatives for select cases involving anatomic anomalies, should be performed at specialized units.

One-step Percutaneous Transhepatic Cholangioscopy Combined With High-frequency Needle-knife Electrotomy in Biliary Strictures After Liver Transplantation.

Endoscopic management is the mainstay for biliary strictures after liver transplantation. However, this method is often failed in cases associated with hepatolithiasis or refractory strictures. The aim of this study is to investigate whether 1-step percutaneous transhepatic biliary cholangiography (PTC) combined with high-frequency needle-knife electrotomy can be an alternative method in biliary strictures after liver transplantation that could not be treated by endoscopic management. Clinical data of 14 patients suffering from biliary strictures after liver transplantation from June 2014 to January 2018 were retrospectively analyzed. One-step PTC combined with high-frequency needle-knife electrotomy was used to resolve the strictures. One-step PTC was successfully performed in all 14 patients. In 10 of 12 (83.3%) patients with hepatolithiasis, the stones were removed completely. Stricture resolution was detected in 13 of 14 (92.9%) patients at first postoperative choledochoscopy. Three mild adverse events occurred (cholangitis, 2 patients; delayed hemobilia, 1 patient), but were resolved with conservative treatment. The follow-up after supporting catheter removal was 15.7±4.5 months. Only 1 patient (8.3%) had stone recurrence and no stenosis occurred during supporting-catheter-free follow-up. One-step PTC combined with high-frequency needle-knife electrotomy seems to be a useful for treating biliary strictures after liver transplantation.

The application of percutaneous transhepatic cholangioscopy in the treatment of benign bilioenteric anastomotic stricture:a report of 9 cases

Objective: To investigate the feasibility and effectiveness of percutaneous transhepatic cholangioscopy(PTCS) in the treatment of bilioenteric anastomotic stricture after choledochojejunostomy. Methods: From April 2016 to April 2020, the clinical data of 9 patients (7 males and 2 females, aged 40-76 years) who underwent percutaneous transhepatic cholangioscopy(PTCS) for stricture expansion and lithotomy at Department of Hepatobiliary and Pancreatic Surgery, Second Affiliated Hospital of Zhejiang University School of Medicine were retrospectively analyzed. The operation was divided into two stages. In the first stage, ultrasound-guided percutaneous intrahepatic bile duct puncture was performed, and the sheath tube was inserted and fixed. In the second stage, percutaneous choledochoscopy was used for anastomotic stricture after sinus formation.The clinical outcome was evaluated by related biochemical indexes. Results: The operation time was (53.3±31.0)minutes(range:15-120 minutes).The postoperative hospital stay was (4.4±2.3)days(range:2-9 days).After systematic treatment, the preoperative symptoms, such as abdominal pain, jaundice, fever and shivering, disappeared in 8 patients. The range of alkaline phosphatase was 122-1 334 U/L before operation and 85-702 U/L after operation. The range of gamma glutamyl transpeptidase was 44-1 219 U/L before operation and 46-529 U/L after operation. Conclusion: PTCS is a safe and effective option for minimally invasive treatment of bilioenteric anastomotic stricture.

Percutaneous Transhepatic Cholangioscopy Utilizing Different Endoscopes to Optimize Treatment Success in Biliary Cast Syndrome, how a Paediatric Bronchoscope can Help: A Case Report

Percutaneous Transhepatic Cholangioscopy Utilizing Different Endoscopes to Optimize Treatment Success in Biliary Cast Syndrome, how a Paediatric Bronchoscope can Help: A Case Report

A case in which a common bile duct stone and a basket catheter were impacted in the duodenal papilla for which percutaneous transhepatic cholangioscopy treatment was useful

A case in which a common bile duct stone and a basket catheter were impacted in the duodenal papilla for which percutaneous transhepatic cholangioscopy treatment was useful