• Korean Journal of Radiology
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• v.21 no.6
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• pp.695-706
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• 2020

Objective: To investigate the technical and clinical efficacy of the percutaneous insertion of a biliary metallic stent, and to identify the factors associated with biliary stent dysfunction in patients with malignant duodenobiliary obstruction. Materials and Methods: The medical records of 70 patients (39 men and 31 women; mean age, 63 years; range, 38-90 years) who were treated for malignant duodenobiliary obstruction at our institution between April 2007 and December 2018, were retrospectively reviewed. Variables found significant by univariate log-rank analysis (p < 0.2) were considered as suitable candidates for a multiple Cox's proportional hazard model. Results: The biliary stents were successfully placed in all 70 study patients. Biliary stent insertion with subsequent duodenal stent insertion was performed in 33 patients and duodenal stent insertion with subsequent biliary stent insertion was performed in the other 37 study subjects. The median patient survival and stent patency time were 107 days (95% confidence interval [CI], 78-135 days) and 270 days (95% CI, 95-444 days), respectively. Biliary stent dysfunction was observed in 24 (34.3%) cases. Multiple Cox's proportional hazard analysis revealed that the location of the distal biliary stent was the only independent factor affecting biliary stent patency (hazard ratio, 3.771; 95% CI, 1.157-12.283). The median biliary stent patency was significantly longer in patients in whom the distal end of the biliary stent was beyond the distal end of the duodenal stent (median, 327 days; 95% CI, 249-450 days), rather than within the duodenal stent (median, 170 days; 95% CI, 115-225 days). Conclusion: The percutaneous insertion of the biliary metallic stent appears to be a technically feasible, safe, and effective method of treating malignant duodenobiliary obstruction. In addition, a biliary stent system with a distal end located beyond the distal end of the duodenal stent will contribute towards longer stent patency in these patients.

• Clinical Endoscopy
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• v.56 no.6
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• pp.795-801
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• 2023

Background/Aims: Endoscopic biliary drainage is the gold standard treatment for cholangitis. The two methods of biliary drainage are endoscopic biliary stenting and nasobiliary drainage. A novel integrated outside biliary stent and nasobiliary drainage catheter system (UMIDAS NB stent; Olympus Medical Systems) was recently developed. In this study, we evaluated the efficacy of this stent in the treatment of cholangitis caused by common bile duct stones or distal bile duct strictures. Methods: We conducted a retrospective pilot study by examining the medical records of patients who required endoscopic biliary drainage for cholangitis due to common bile duct stones or distal bile duct strictures, and who were treated with a UMIDAS NB stent, between December 2021 and July 2022. Results: Records of 54 consecutive patients were reviewed. Technical and clinical success rates were 47/54 (87.0%) and 52/54 (96.3%), respectively. Adverse events were observed in 12 patients, with six patients experiencing pancreatitis as an adverse event, following endoscopic retrograde cholangiopancreatography (ERCP). Regarding late adverse events, five cases of biliary stent migration into the bile duct were observed. Disease-related death occurred in one patient. Conclusions: The outside-type UMIDAS NB stent is an efficacious new method for biliary drainage and can be applied to many indications.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.194-197
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• 2023

Ascaris lumbricoides causes one of the most common soil-transmitted helminthiases globally. The worms mostly infect the human small intestine and elicit negligible or nonspecific symptoms, but there are reports of extraintestinal ectopic ascariasis. We describe a rare case of biliary ascariasis mistaken for biliary stent in a 72-year-old female patient with a history of liver resection. She visited our outpatient clinic complaining of right upper quadrant pain and fever for the past week. She had previously undergone left lateral sectionectomy for recurrent biliary and intrahepatic duct stones 2 years ago. Besides mildly elevated gamma-glutamyl transferase levels, her liver function tests were normal. Magnetic resonance cholangiopancreatography revealed a linear filling defect closely resembling an internal stent from the common bile duct to the right intrahepatic bile duct. A live female A. lumbricoides adult worm was removed by endoscopic retrograde cholangiopancreatography (ERCP). Despite a significant decrease of the ascariasis prevalence in Korea, cases of biliary ascariasis are still occasionally reported. In this study, a additional case of biliary ascariasis, which was radiologically misdiagnosed as the biliary stent, was described in a hepatic resection patient by the worm recovery with ERCP in Korea.

• Clinical Endoscopy
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• v.56 no.2
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• pp.143-154
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• 2023

Advanced malignant hilar biliary obstruction (MHBO) with inaccessible papilla poses a significant challenge to endoscopists, as drainage of multiple liver segments may be warranted. Transpapillary drainage may not be feasible in patients with surgically altered anatomy, duodenal stenosis, prior duodenal self-expanding metal stent, and after initial transpapillary drainage, but require re-intervention for draining separated liver segments. Endoscopic ultrasound-guided biliary drainage (EUS-BD) and percutaneous trans-hepatic biliary drainage are the feasible options in this scenario. The major advantages of EUS-BD over percutaneous trans-hepatic biliary drainage include a reduction in patient discomfort and internal drainage away from the tumor, thus reducing the possibility of tissue or tumor ingrowth. With innovations, EUS-BD is helpful not only for bilateral communicating MHBO but also for non-communicating systems with bridging hilar stents or isolated right intra-hepatic duct drainage by hepatico-duodenostomy. EUS-guided multi-stent drainage with specially designed cannulas and guidewires has become a reality. A combined approach with endoscopic retrograde cholangiopancreatography for re-intervention, interventional radiology, and intraductal tumor ablative therapies has been reported. Stent migration and bile leakage can be minimized with proper stent selection and technique, and stent blocks can be managed with EUS-guided interventions in a majority of cases. Future comparative studies are required to establish the role of EUS-guided interventions in MHBO as rescue or primary therapy.

• Journal of Digestive Cancer Research
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• v.10 no.2
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• pp.92-98
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• 2022

Self-expandable metal stent (SEMS) is effective for biliary drainage, especially in pancreaticobiliary cancer. The mechanical properties, material, and design of SEMS are important in preventing recurrent biliary obstruction and complication. Radial and chronic expansion forces play roles in preventing stent migration and collapse. Complications, such as stent impaction, cholecystitis, and pancreatitis, were related to the axial force. The nickel-titanium alloy shows more flexibility, conformability, and optimal axial force compared to previously used stainless steel. Additionally, the stent structure affected the mechanical properties of SEMS. Therefore, understanding the mechanical properties, material, and design of SEMS will provide the best outcome for biliary drainage, as well as better SEMS development.

• Clinical Endoscopy
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• v.56 no.2
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• pp.135-142
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• 2023

Endoscopic biliary drainage strategies for managing unresectable malignant hilar biliary obstruction differ in terms of stent type, drainage area, and deployment method. However, the optimal endoscopic drainage strategy remains unclear. Uncovered self-expandable metal stents (SEMS) are the preferred type because of their higher functional success rate, longer time to recurrent biliary obstruction (RBO), and fewer cases of reintervention than plastic stents (PS). Other PS subtypes and covered SEMS, which feature a longer time to RBO than PS, can be removed during reintervention for RBO. Bilateral SEMS placement is associated with a longer time to RBO and a longer survival time than unilateral SEMS placement. Unilateral drainage is acceptable if a drainage volume of greater than 50% of the total liver volume can be achieved. In terms of deployment method, no differences were observed in clinical outcomes between side-by-side (SBS) and stent-in-stent deployment. Simultaneous SBS boasts a shorter procedure time and higher technical success rate than sequential SBS. This review of previous studies aimed to clarify the optimal endoscopic biliary drainage strategy for unresectable malignant hilar biliary obstruction.

• Korean Journal of Radiology
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• v.23 no.9
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• pp.889-900
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• 2022

Objective: To investigate the long-term outcomes of percutaneous treatment of benign biliary strictures using temporary placement of a retrievable expanded polytetrafluoroethylene (PTFE) covered stent. Materials and Methods: We retrospectively analyzed the outcomes of 148 patients (84 male and 64 female; age range, 11-92 years) who underwent percutaneous transhepatic placement and removal of a retrievable PTFE-covered stent for the treatment of benign biliary strictures between March 2007 and August 2019 through long-term follow-up. Ninety-two patients had treatment-naïve strictures and 56 had recurrent/refractory strictures. Results: Stent placement was technically successful in all 148 patients. The mean indwelling period of the stent was 2.4 months (median period, 2.3 months; range, 0.2-7.7 months). Stent migration, either early or late, occurred in 28 (18.9%) patients. Clinical success, defined as resolution of stricture after completing stent placement and removal, was achieved in 94.2% (131 of 139 patients). The overall complication rate was 15.5% (23 of 148 patients). During the mean follow-up of 60.2 months (median period, 52.7 months; range, 1.6-146.1 months), 37 patients had a recurrence of clinically significant strictures at 0.5-124.5 months after removal of biliary stent and catheter (median, 16.1 months). The primary patency rates at 1, 3, 5, 7, and 10 years after removal of biliary stent and catheter were 88.2%, 70.0%, 66.2%, 60.5%, and 54.5%, respectively. In the multivariable Cox proportional hazard regression analysis, sex, age, underlying disease, relation to surgery, stricture type, biliary stones, history of previous treatment, and stricture site were not significantly associated with the primary patency. Conclusion: Long-term outcomes suggest that percutaneous treatment of benign biliary strictures using temporary placement of retrievable PTFE-covered stents may be a clinically effective method.

• The Korean Journal of Pancreas and Biliary Tract
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• v.22 no.4
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• pp.165-171
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• 2017

Background/Aim: There is little data on whether plastic stents with a larger diameter are patent for longer than small stents in patients with bile duct cancer. The aim of this study was to compare the stent survival between 7-French (Fr) and 10-Fr plastic stents and evaluate the factors affecting stent survival. Methods: Patients with biliary obstruction due to biliary tract cancer were enrolled at Yonsei University Wonju College of Medicine from January 2010 to October 2014. Results: A total of 215 patients (7-Fr:10-Fr = 89:126 patients) were retrospectively enrolled. The primary tumor sites were common bile duct (n = 111), hilar (n = 45), and ampulla of Vater (n = 59). Rates of stent migration and stent obstruction were not different between the two groups. The median duration of stent survival was 3.3 months in the 7-Fr group and 5.9 months in the 10-Fr group (p = 0.543). The diameter of the stent did not have an effect on stent survival (hazard ratio 1.11, 95% confidence interval 0.71-1.73, p = 0.649). Conclusions: 7-Fr and 10-Fr stents have similar rates of stent migration and stent obstruction. The stent survival of 7-Fr was not inferior to 10-Fr stents in the management of biliary tract cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.529-532
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• 2013

Cholangiocarcinoma, though very rare in Western countries, is one of the commonest liver malignancies in Southeast Asia, especially in Thailand. More than half of the patients present with advanced stage disease. Given the poor treatment outcomes of adjuvant therapeutic options, many patients undergo only biliary drainage for palliative treatment. Clinical characteristics and treatment outcomes after biliary stenting were here analyzed for a total of 224 uresectable cholangiocarcinoma cases, 58.9% in men. The mean age was 61.5 years. Hilar involvement was the most common location. The patients underwent biliary drainage using plastic and metallic stents equally, early stent occlusion being encountered in 21.4% and 10.7%, respectively. The median survival time was 4.93 months for patients who received plastic and 5.87 months for patients who received metallic stents.

• Clinical Endoscopy
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• v.56 no.2
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• pp.169-179
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• 2023

Background/Aims: This meta-analysis analyzed the effect of an indwelling biliary stent on endoscopic ultrasound (EUS)-guided tissue acquisition from pancreatic lesions. Methods: A literature search was performed to identify studies published between 2000 and July 2022 comparing the diagnostic outcomes of EUS-tissue acquisition (TA) in patients with or without biliary stents. For non-strict criteria, samples reported as malignant or suspicious for malignancy were included, whereas for strict criteria, only samples reported as malignant were included in the analysis. Results: Nine studies were included in this analysis. The odds of an accurate diagnosis were significantly lower in patients with indwelling stents using both non-strict (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.52-0.90) and strict criteria (OR, 0.58; 95% CI, 0.46-0.74). The pooled sensitivity with and without stents were similar (87% vs. 91%) using non-strict criteria. However, patients with stents had a lower pooled sensitivity (79% vs. 88%) when using strict criteria. The sample inadequacy rate was comparable between groups (OR, 1.12; 95% CI, 0.76-1.65). The diagnostic accuracy and sample inadequacy were comparable between plastic and metal biliary stents. Conclusions: The presence of a biliary stent may negatively affect the diagnostic outcome of EUS-TA for pancreatic lesions.