Endoscopic Ultrasound-Guided Naso-gallbladder Drainage Using a Dedicated Catheter for Acute Cholecystitis After Transpapillary Metal Stent Placement for Malignant Biliary Obstruction

BACKGROUND

Acute cholecystitis is a significant adverse event after self-expandable metal stent (SEMS) placement for malignant biliary obstruction (MBO); however, no appropriate treatment strategy has been established for its management.

AIMS

This study aimed to examine the feasibility and utility of endoscopic ultrasound-guided naso-gallbladder drainage (EUS-NGBD) for the management of acute cholecystitis occurring after SEMS placement.

METHODS

This retrospective study investigated consecutive patients with acute cholecystitis after SEMS placement for unresectable MBO, in whom EUS-NGBD was attempted. The study outcomes included technical success, clinical success, procedure time, adverse event, and cholecystitis recurrence, associated with the procedure.

RESULTS

During the study period, EUS-NGBD was performed for SEMS-related acute cholecystitis in 30 patients with MBO. The technical and clinical success rates were 96.7% (29/30) and 96.6% (28/29), respectively. The median procedure time was 15 min, and rate of procedure-related adverse event was 3.3% (1/30). The median duration from the procedure to tube removal was 9 days. No adverse events were observed after removal. The median hospitalization duration after the procedure was 14 days, and the median duration to the (re-)start of chemotherapy from cholecystitis onset was 13 days. The median overall survival after EUS-NGBD was 123 days, and the rate of cholecystitis recurrence until death was 4.2% (1/28).

CONCLUSIONS

This study demonstrated that EUS-NGBD possesses good technical and clinical feasibility with an acceptable adverse event rates and short hospitalization and chemotherapy withdrawal period. Therefore, EUS-NGBD may be a good option for the treatment of SEMS-related cholecystitis in patients with MBO.

Endoscopic gallbladder inside-stenting combined with aspirated lavage for calculous cholecystitis in poor surgical candidates: a prospective pilot study

Although long-term stent placement via endoscopic gallbladder stenting (EGBS) reportedly reduces cholecystitis recurrence in patients unfit to undergo cholecystectomy, it can increase the frequency of other late adverse events (AEs) such as cholangitis. This study aimed to examine the feasibility of endoscopic gallbladder inside-stenting (EGB-IS) with lavage and aspiration. This prospective, single-center, pilot study enrolled 83 patients with acute calculous cholecystitis who were poor candidates for surgery. A dedicated catheter with eight side holes was used for lavage and aspiration, and a dedicated single-pigtail stent equipped with a thread was used for EGB-IS. Outcomes such as technical success, clinical success, early AEs, recurrence of cholecystitis, and other symptomatic late AEs associated with EGB-IS with lavage and aspiration were evaluated. The technical and clinical success rates were 80.7% (67/83) and 98.5% (66/67), respectively. The rate of early AEs was 3.6% (3/83). The rate of recurrent cholecystitis was 4.5% (3/66) and that of symptomatic late AEs (besides cholecystitis) was 6.1% (4/66). Consequently, the rate of overall late AEs (cholecystitis plus other events) was 10.6% (7/66). The 1-, 2-, and 3-year cumulative incidence rates of all late AEs were 3.2%, 11.2%, and 18.9%, respectively. EGB-IS with lavage and aspiration for calculous cholecystitis showed promising results in poor surgical candidates. EGB-IS may be useful when EGBS with long-term stent placement is planned, since prevention of cholecystitis recurrence, without a rise in the incidence of other AEs, is anticipated.

Comparison of the mechanical properties of retrieval basket catheters for bile duct stones: An experimental study

BACKGROUND

Although numerous retrieval baskets are currently available for the extraction of bile duct stones, their mechanical properties have not been evaluated. This study aimed to ascertain the characteristics of retrieval baskets for bile duct stones by examining their mechanical properties.

METHODS

This experimental study tested the mechanical properties of seven retrieval baskets for bile duct stones. The radial force (RF) was measured using a dedicated measurement device and the axial force (AF) was measured using the conventional manual method.

RESULTS

The mean RF differed significantly among the baskets (p < 0.001) and was the strongest for VorticCatch (1.62 N ± 0.02) and COAXIS (1.62 N ± 0.04), followed by RASEN (1.27 N ± 0.02), Memory Basket (0.95 N ± 0.01), 8-wire Nitinol Basket (0.93 N ± 0.01), StoneHunter (0.78 N ± 0.01) and Flower Basket (0.37 N ± 0.01), respectively. The mean AF differed significantly among the baskets (p < 0.001) and was the highest for VorticCatch (0.668 N ± 0.032), followed by COAXIS (0.629 N ± 0.041), StoneHunter (0.574 N ± 0.037), 8-wire Nitinol Basket (0.546 N ± 0.010), Memory Basket (0.542 N ± 0.024), RASEN (0.435 N ± 0.008) and Flower Basket (0.297 N ± 0.011), respectively. The baskets were categorized into four groups with comparable mechanical properties based on the RF and AF: group 1, low RF and low AF; group 2, moderate RF and moderate AF; group 3, high RF and moderate AF; and group 4, high RF and high AF.

CONCLUSIONS

This study revealed distinct mechanical properties of various retrieval baskets used for extracting bile duct stones, which may enhance the understanding of their action. Our results could also aid the development of retrieval baskets in future.

Endoscopic intraductal radiofrequency ablation for extrahepatic cholangiocarcinoma: An update (2023)

Recently, endoscopic intraductal radiofrequency ablation (ID-RFA) has attracted attention as a local treatment method for malignant biliary obstruction (MBO). ID-RFA causes coagulative necrosis of the tumor tissue in the stricture and induces exfoliation. Its effects are expected to extend the patency period of biliary stents and prolong the survival period. Evidence for extrahepatic cholangiocarcinoma (eCCA) is gradually accumulating, and some reports show significant therapeutic effects in eCCA patients without distant metastasis. However, it is still far from an established treatment technique, and many unsolved problems remain. Therefore, when performing ID-RFA in clinical practice, it is necessary to understand and grasp the current evidence well and to operate appropriately for the true benefit of the patients. This paper reviews the current status, issues, and prospects of endoscopic ID-RFA for MBO, especially for eCCA.

A novel controllable cannula with a short flexible tip for reintervention after stent-by-stent placement in malignant hilar biliary obstruction

N/A.

A novel non-slip banded balloon catheter for endoscopic sphincteroplasty: an ex vivo and in vivo pilot study

Endoscopic balloon sphincteroplasty is an established procedure for the extraction of bile duct stones. However, the balloon often slips during the inflation process, and its length is an impediment if the distance between the papilla and scope is limited and/or the stone is located close to the papilla. This animal experimental study aimed to evaluate the feasibility of a novel short non-slip banded balloon measuring 15-20 mm in length for sphincteroplasty. The ex vivo component of this study was conducted using porcine duodenal papilla. Miniature pigs were subjected to endoscopic retrograde cholangiography in the in vivo component. The technical success of sphincteroplasty without any slippage was the primary outcome of the study and was compared between cases managed with the non-slip banded balloon (non-slip balloon group) and conventional balloon (conventional balloon group). The technical success rate of the ex vivo component, i.e., absence of any slippage, was significantly higher in the non-slip balloon group than in the conventional balloon group with the 8-mm (96.0% vs. 16.0%, P < 0.001) and 12-mm diameter balloons (96.0% vs. 0%, P < 0.001). The technical success rate of endoscopic sphincteroplasty without slippage in the in vivo component was significantly higher in the non-slip balloon group than in the conventional balloon group (100% vs. 40%, P = 0.011). No immediate adverse events were observed in either group. The slippage rate was significantly lower with sphincteroplasty using a non-slip balloon, despite the balloon length being considerably shorter than that of conventional balloons, demonstrating its potential utility in difficult cases.

Double bare metal stent deployment combined with intraductal radiofrequency ablation for malignant distal biliary obstruction: a prospective pilot study

Although uncovered self-expandable metal stents (SEMSs) possess certain advantages such as averting cystic duct obstruction and stent migration, they are susceptible to ingrowth occlusion. The combination of the double bare stent (DBS) and endobiliary radiofrequency ablation (RFA) may reduce ingrowth. Hence, this study aimed to examine the utility of this method for the treatment of unresectable malignant distal biliary obstruction (MDBO). This prospective, single-center, pilot study enrolled 51 patients who met the eligibility criteria between February 2020 and January 2022. The study outcomes included technical success, clinical success, recurrent biliary obstruction (RBO), and other adverse events (AE) besides RBO associated with DBS placement with RFA for MDBO. The technical success rate was 98.0% (50/51). Clinical success was achieved in all patients in whom technical success was achieved. The rates of early and late AEs were 5.9% (3/51) and 8.0% (4/50), respectively. The incidence rate of RBO was 38.0% (19/50). Sludge occlusion, ingrowth occlusion, and overgrowth occlusion occurred in 26.0% (13/50), 8.0% (4/50), and 2.0% (1/50) of patients, respectively (the main cause of RBO was undeterminable in 1 patient). The median time to RBO was 241 days. DBS with RFA showed good technical feasibility, good long-term outcomes, acceptable AE rates, and most importantly, a low ingrowth occlusion rate when employed for the treatment of MDBO.

Recent Updates on Local Ablative Therapy Combined with Chemotherapy for Extrahepatic Cholangiocarcinoma: Photodynamic Therapy and Radiofrequency Ablation

Although chemotherapy constitutes of the first-line standard therapy for unresectable extrahepatic cholangiocarcinoma, the treatment outcomes are unsatisfactory. In recent years, local ablative therapy, which is delivered to the cholangiocarcinoma lesion via the percutaneous or endoscopic approach, has garnered attention for the treatment of unresectable, extrahepatic cholangiocarcinoma. Local ablative therapy, such as photodynamic therapy and radiofrequency ablation, can achieve local tumor control. A synergistic effect may also be expected when local ablative therapy is combined with chemotherapy. However, it is a long way from being entrenched as an established therapeutic technique, and several unresolved problems persist, including the paucity of evidence comparing photodynamic therapy and radiofrequency ablation. Clinical application of photodynamic therapy and radiofrequency ablation requires sound comprehension and assimilation of the available evidence to truly benefit each individual patient. In this study, we reviewed the current status, issues, and future prospects of photodynamic therapy and radiofrequency ablation for extrahepatic cholangiocarcinoma, with a special focus on their combination with chemotherapy.

Endoscopic radiofrequency ablation for ingrowth occlusion after bilateral metal stent placement for malignant hilar biliary obstruction: a prospective pilot study

BACKGROUND AND AIMS

Endoscopic biliary radiofrequency ablation (RFA) may be an option for the treatment of ingrowth occlusion after self-expandable metal stent (SEMS) deployment; however, its utility remains uncertain. This study aimed to examine the feasibility of RFA for the palliation of ingrowth after bilateral SEMS placement in patients with malignant hilar biliary obstruction.

METHODS

This prospective, single-center, pilot study enrolled 30 patients who met the eligibility criteria between April 2020 and March 2022. Study outcomes were technical success, clinical success, recurrent biliary obstruction (RBO), and adverse events (AEs) besides RBO associated with RFA for ingrowth occlusion. Furthermore, factors predictive of clinical success were evaluated.

RESULTS

Technical and clinical success rates were 93.3% (28/30) and 71.4% (20/28), respectively. The rates of early and late AEs were 6.7% (2/30) and 10.0% (2/20), respectively. The incidence rate of RBO after RFA was 45.0% (9/20), and the median time to RBO was 163 days. Multivariate analysis of the factors affecting clinical success revealed a positive association between the recanalization diameter on the ingrown part within the SEMS (odds ratio, 1.13; 95% confidence interval, 1.01-1.26; P = .038). The calculated optimal cutoff for the ratio of the recanalization diameter to the SEMS diameter for predicting clinical success was 51.1%.

CONCLUSIONS

Endoscopic biliary RFA elicited promising results, with good long-term stent patency and without the requirement of any additional stent placement, for the palliation of ingrowth occlusion after bilateral SEMS placement. However, the clinical success rate was insufficient, necessitating improvements in the future. (Clinical trial registration number: UMIN000040154.).

Endoscopic biliary ethanol ablation using a novel multi-hole balloon catheter: In vivo feasibility study in a swine model

BACKGROUND

Minimally invasive local treatment could be a good option for the treatment of extrahepatic cholangiocarcinoma (eCCA). This study aimed to evaluate the feasibility of a novel local treatment method, endoscopic biliary ethanol ablation (EA), in vivo using a swine model.

METHODS

This study utilized a prototype of the newly developed multi-hole balloon catheter. The swine bile duct was ablated using this balloon via the same approach as the conventional endoscopic retrograde cholangiography procedure. The study outcomes included technical success, clinical success, and adverse events associated with endoscopic biliary EA.

RESULTS

Fourteen miniature pigs underwent endoscopic biliary EA. Technical success was achieved for all endoscopic EA procedures without any hindrance. All pigs were reared and followed up for a median 35-day period after the procedure. No change was observed in the bile duct wall in one case, in which sufficient contact was not achieved between the balloon and bile duct wall. Except for this case, stricture formation occurred at the site of ablation, where the epithelium was sloughed and necrosis with denaturation replaced the granulation tissue and fibrotic changes. The median length and depth of the ablation area were 17.05 and 2.21 mm, respectively. No adverse events were observed, except for the formation of bile duct strictures and sequelae associated with strictures.

CONCLUSIONS

This preliminary study was the first to report endoscopic biliary EA using a novel multi-hole balloon catheter, which demonstrated technical feasibility and potential for the treatment for eCCA.

Trends of hepatitis B virus genotype distribution in chronic hepatitis B patients in Japan

BACKGROUND

Hepatitis B virus (HBV) is one of the most prevalent chronic viral infections that causes chronic hepatitis B (CHB). In Japan, genotypes B and C account for most of acute and chronic cases of hepatitis. However, previous studies showed that the prevalence of genotype A in CHB gradually increased every 5 years. Therefore, we have conducted a nationwide survey to comprehensively investigate the trends of HBV genotype distribution in CHB patients in Japan.

METHODS

4421 CHB patients were recruited between 2015 and 2016. Clinical characteristics and distribution of CHB patients among different age groups and genotypes in 2015-2016 was compared with those in 2000-2001, 2005-2006, and 2010-2011.

RESULTS

The percentages of genotype A, B, C, and D were 4.0, 16.2, 79.1, and 0.7%, respectively. While the overall percentage of CHB patients with genotype A did not change in the past 5 years, CHB with genotype A increased in young adults. On the other hand, the peak distribution of CHB with genotypes B and C, two genotypes with the largest patient population, has shifted to an older age group.

CONCLUSIONS

In Japan, the peak distribution for CHB with genotypes B and C advanced to an older age group while CHB with genotype A expanded in a younger age group. Given the universal HBV vaccination launch in Japan in 2016, these pre-vaccination survey data provide important baseline information for comparative studies of the impact of universal vaccination on HBV genotypes.

Comparison of the removal ability of basket catheters for small bile duct stones impacted in the corner pocket of the lower bile duct

BACKGROUND : Endoscopic stone extraction is often challenging in patients with a significant lower bile duct corner pocket, where small stones are likely to escape and become impacted. This study aimed to determine the utility of different types of baskets for retrieving corner pocket stones. METHODS : Seven types of retrieval baskets were evaluated on silicone models. The study outcomes included the characteristics of each basket and technical success rates associated with the retrieval of stones impacted in the corner pocket. RESULTS : The overall success rate was only 27.5 %, with significant differences between the baskets (P < 0.001). Only three baskets yielded successful removal. The success rates were 10 %, 25 %, and 70 % with the 8-wire Nitinol Basket, RASEN, and VorticCatch V, respectively, all of which are helical eight-wire baskets. RASEN and VorticCatch V share similar characteristics, including a strong spiral wire and smaller interwire spaces at their distal ends. The addition of rotation significantly increased the success rate to 80 % with the 8-wire Nitinol Basket (P < 0.001) and 90 % with RASEN (P < 0.001). CONCLUSIONS : Robust helical eight-wire baskets with smaller interwire spaces at the tip may be effective for extracting corner pocket stones, while the addition of rotational motion may improve the efficacy of retrieval.

Endobiliary Radiofrequency Ablation Using a Short-Type Balloon Enteroscope in Patients with Surgically Altered Anatomy

BACKGROUND

Endoscopic radiofrequency ablation (RFA) is expected to prolong stent patency for malignant biliary obstruction (MBO). However, its feasibility when used in conjunction with a balloon enteroscope (BE) in patients with surgically altered anatomy (SAA) remains unknown.

AIMS

This study aimed to investigate the feasibility of RFA combined with metal stent insertion under BE guidance for MBO in patients with SAA.

METHODS

Thirty-seven patients who underwent treatment between October 2016 and January 2021 and met the eligibility criteria were investigated retrospectively. Study outcomes included technical and clinical success, recurrent biliary obstruction (RBO), and other adverse events besides RBO associated with RFA with metal stent placement using BE.

RESULTS

Technical and clinical success rates were 100% (37/37) each. The rates of early and late adverse events were 8.1% (3/37) and 8.1% (3/37), respectively. RBO occurred in 32.4% (12/37) of the patients, and the median time to RBO was 296 days. The cause of RBO was ingrowth in eight patients, overgrowth in three patients, and indeterminate in one patient. All reinterventions for RBO were successful using the BE approach; all ingrowths, except one, were recanalized using additional RFA without additional stent placement. The frequency of reintervention-related adverse events was 9.1% (1/11). The median time to RBO after reintervention was 166 days.

CONCLUSIONS

This study demonstrated the technical safety and feasibility as well as good long-term outcomes of endobiliary RFA combined with metal stent placement under BE guidance. This approach may be a useful option for treating MBO in patients with SAA.

Safety and Efficacy of Gemcitabine Plus Nab-Paclitaxel for Metastatic Pancreatic Cancer Patients Undergoing Biliary Stent Placement

BACKGROUND

Gemcitabine plus nab-paclitaxel (GnP) is the first-line chemotherapeutic regimen for metastatic pancreatic cancer (MPC); however, there are concerns regarding its safety in patients undergoing biliary stent placement. This study aimed to examine the tolerability and efficacy of GnP in MPC patients who underwent biliary stent placement.

METHODS

A total of 105 MPC patients who had received GnP treatment between 2015 and 2020 were included and investigated. The patients were divided into two groups: those undergoing biliary stent placement for symptomatic biliary obstruction (BO) (With-BO group) and those without biliary stent placement (Without-BO group). The best tumor response, overall survival (OS), and adverse events in each group were compared.

RESULTS

The partial response, stable disease, and progressive disease rates were 22%, 61%, and 14.6% in the With-BO group, and 26.6%, 46.9%, and 21.9% in the Without-BO group, respectively, with no significant differences. The median OS was 12.2 months and 14.6 months in the With-BO and Without-BO groups, respectively (P = 0.483). Grade 3 or higher biliary tract-related events were significantly more common in the With-BO group (41.5%) than in the Without-BO group (1.6%) (P < 0.001), but all events were managed successfully by urgent intervention. The rates of any treatment-related toxicities, including febrile neutropenia, were not significantly different, and there were no chemotherapy-related deaths in either group.

CONCLUSIONS

GnP can be as tolerable and effective in MPC patients with biliary stents as in those without biliary stents. However, careful management and appropriate reintervention to treat biliary tract-related adverse events are required.

Scissor-type knife precut in balloon enteroscopy-assisted ERCP for patients with difficult biliary cannulation and surgically altered anatomy (with video)

BACKGROUND AND AIMS

Balloon enteroscopy-assisted ERCP (BE-ERCP) is useful for treating pancreatobiliary disease in patients with surgically altered anatomy (SAA); however, biliary cannulation, including the precut technique, is often challenging. This study aimed to examine the feasibility of scissor-type knife precutting (SKP) during BE-ERCP in patients with SAA.

METHODS

This retrospective study investigated consecutive patients who underwent BE-ERCP and SKP for difficult biliary cannulation between 2016 and 2021. The study outcomes included the technical success and adverse event rates associated with SKP during BE-ERCP.

RESULTS

During the study period, 125 patients with native duodenal papillae underwent BE-ERCP, and the papilla was reached in 116 patients. The success rate of biliary cannulation with the standard cannulation approach alone was 67.2% (78/116), which increased to 77.6% (90/116) with the inclusion of advanced cannulation techniques besides precutting and further improved to 87.9% (102/116) with the addition of needlife precutting. SKP was attempted in 12 patients in whom all other cannulation approaches were difficult or resulted in failure. The technical success rate of SKP was 66.7% (8/12); thus, SKP increased the final success rate of biliary cannulation to 94.8% (110/116). The rate of adverse events associated with SKP was 8.3% (1/12).

CONCLUSIONS

This is the first study to report the use of the SKP technique for difficult biliary cannulation in patients with SAA, which may serve as a useful option for salvage cannulation during BE-ERCP.

Endobiliary Radiofrequency Ablation Combined with Gemcitabine and Cisplatin in Patients with Unresectable Extrahepatic Cholangiocarcinoma

Background: Endobiliary radiofrequency ablation (RFA) is a promising treatment modality for patients with extrahepatic cholangiocarcinoma (eCCA). However, no study has investigated the combined use of endobiliary RFA and gemcitabine plus cisplatin (GC) chemotherapy. This study aimed to examine the feasibility and efficacy of endobiliary RFA with GC therapy for patients with unresectable eCCA. Methods: The study outcomes included overall survival (OS), progression-free survival (PFS), time to recurrent biliary obstruction (RBO), and adverse events associated with the treatment. These parameters were retrospectively compared between 25 patients who underwent RFA with self-expandable metal stent (SEMS) placement followed by GC therapy (with-RFA group) and a control cohort of 25 patients who underwent SEMS placement alone and GC therapy (without-RFA group). Results: The median time to RBO was significantly longer in the with-RFA group (10.7 versus 5.2 months, p = 0.048). The median OS was significantly higher in patients with locally advanced tumors in the with-RFA group (23.1 versus 16.6 months, p = 0.032), but did not differ significantly in patients with metastasis (11.4 versus 8.5 months, p = 0.180). Similarly, the median PFS was significantly higher in the with-RFA group in patients with locally advanced disease (10.1 versus 7.3 months, p = 0.015), while there was no significant difference in patients with metastasis (5.4 versus 4.4 months, p = 0.529). The rates of various toxicities did not differ significantly between the groups. Conclusions: Endobiliary RFA prolonged the patency period of uncovered SEMS combined with GC therapy in patients with eCCA. Although RFA also yielded survival benefits, its effect was restricted to locally advanced tumors.

Updated evidence on the clinical impact of endoscopic radiofrequency ablation in the treatment of malignant biliary obstruction

Endoscopic biliary radiofrequency ablation (RFA) was recently developed as a novel adjunctive procedure and a promising therapeutic option in patients with malignant biliary obstruction (MBO). RFA can achieve local tumor control, resulting in improved biliary stent patency and a potential survival benefit. However, the efficacy of biliary RFA remains controversial, and previous studies have shown conflicting results. At present, extrahepatic cholangiocarcinoma is considered the condition most effectively treated by biliary RFA, but there is limited research even on this point. Further, limitations of RFA associated with the devices used during the procedure are an important subject of discussion. In addition to further well-designed clinical trials, development of innovative devices is warranted to investigate and conclusively establish the usefulness of biliary RFA. In this review we summarize the updated evidence regarding the use of endoscopic biliary RFA for MBO and discuss issues that should be addressed in future studies.

Role of vitamin E in the treatment of non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH), a severe form of non-alcoholic fatty liver disease (NAFLD), can progress to cirrhosis, hepatocellular carcinoma (HCC), and hepatic failure/liver transplantation. Indeed, NASH will soon be the leading cause of HCC and liver transplantation. Lifestyle intervention represents the cornerstone of NASH treatment, but it is difficult to sustain. However, no pharmacotherapies for NASH have been approved. Oxidative stress has been implicated as one of the key factors in the pathogenesis of NASH. Systematic reviews with meta-analyses have confirmed that vitamin E reduces transaminase activities and may resolve NASH histopathology without improving hepatic fibrosis. However, vitamin E is not recommended for the treatment of NASH in diabetes, NAFLD without liver biopsy, NASH cirrhosis, or cryptogenic cirrhosis. Nevertheless, vitamin E supplementation may improve clinical outcomes in patients with NASH and bridging fibrosis or cirrhosis. Further studies are warranted to confirm such effects of vitamin E and that it would reduce overall mortality/morbidity without increasing the incidence of cardiovascular events. Future clinical trials of the use of vitamin E in combination with other anti-fibrotic agents may demonstrate an additive or synergistic therapeutic effect. Vitamin E is the first-line pharmacotherapy for NASH, according to the consensus of global academic societies.

Evidence-based clinical practice guidelines for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis 2020

Nonalcoholic fatty liver disease (NAFLD) has become a serious public health issue not only in Western countries but also in Japan. Within the wide spectrum of NAFLD, nonalcoholic steatohepatitis (NASH) is a progressive form of disease that often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma (HCC). While a definite diagnosis of NASH requires liver biopsy to confirm the presence of hepatocyte ballooning, hepatic fibrosis is the most important prognostic factor in NAFLD. With so many NAFLD patients, it is essential to have an effective screening method for NAFLD with hepatic fibrosis. As HCC with non-viral liver disease has increased markedly in Japan, effective screening and surveillance of HCC are also urgently needed. The most common death etiology in NAFLD patients is cardiovascular disease event. Gastroenterologists must, therefore, pay close attention to CVD when examining NAFLD patients. In the updated guidelines, we propose screening and follow-up methods for hepatic fibrosis, HCC, and CVD in NAFLD patients. Several drug trials are ongoing for NAFLD/NASH therapy, however, there is currently no specific drug therapy for NAFLD/NASH. In addition to vitamin E and thiazolidinedione derivatives, recent trials have focused on sodium glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) analogues, and effective therapies are expected to be developed. These practical guidelines for NAFLD/NASH were established by the Japanese Society of Gastroenterology in conjunction with the Japan Society of Hepatology. Clinical evidence reported internationally between 1983 and October 2018 was collected, and each clinical and background question was evaluated using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. This English summary pro- vides the core essentials of these clinical practice guidelines, which include the definition and concept, screening systems for hepatic fibrosis, HCC and CVD, and current therapies for NAFLD/NASH in Japan.

Feasibility of balloon-based endobiliary radiofrequency ablation under cholangioscopy guidance in a swine model

Although endobiliary radiofrequency ablation (RFA) has demonstrated considerable potential for the treatment of biliary strictures, conventional catheter RFA has several limitations. This study aimed to evaluate the feasibility of a novel cholangioscopy (CS)-guided balloon-based RFA procedure in vivo using a swine model. CS-guided balloon-RFA was performed under endoscopic retrograde cholangiography guidance at target temperatures of 60 ℃ or 70 ℃, which were maintained for 60 s. We evaluated the technical feasibility, adverse events, and histological effects associated with the procedure. Twelve sites were ablated in seven miniature pigs. The CS-guided balloon-RFA procedure was technically successful in all cases without any hindrance. Mucosal changes could be detected during RFA, and the ablation area was identified on CS. Necropsy was performed in four pigs on the same day as the procedure: the tissue samples showed coagulative necrosis, and the entire internal circumference of the bile duct was uniformly ablated. The mean lengths of the ablation area in the samples ablated at 60 °C and 70 °C were 20.64 and 22.18 mm, respectively, while the mean depths were 3.46 and 5.07 mm, respectively. The other three pigs were reared and euthanized and autopsied 35 days after the procedure. The site to be ablated had replaced the granulation tissue and fibrotic changes. No adverse events were observed in any case. CS-guided balloon-RFA appears to be a promising option for treating biliary strictures. This preliminary study could pave the way for the evaluation of this procedure in future human clinical trials.

Dual Agonist of Farnesoid X Receptor and Takeda G Protein-Coupled Receptor 5 Inhibits Hepatitis B Virus Infection In Vitro and In Vivo

BACKGROUND AND AIMS

Chronic HBV infection is a major health problem worldwide. Currently, the first-line treatment for HBV is nucleos(t)ide analogs or interferons; however, efficient therapeutic approaches that enable cure are lacking. Therefore, anti-HBV agents with mechanisms distinct from those of current drugs are needed. Sodium taurocholate cotransporting polypeptide (NTCP) was previously identified as an HBV receptor that is inhibited by several compounds. Farnesoid X receptor (FXR) activation also inhibits NTCP function.

APPROACH AND RESULTS

In this study, we investigated the inhibitory effect of bile acid (BA) derivatives-namely obeticholic acid (OCA), 6α-ethyl-24-nor-5β-cholane-3α,7α,23-triol-23 sulfate sodium salt (INT-767; a dual agonist of FXR and Takeda G protein-coupled receptor [TGR5]), and 6α-ethyl-23(S)-methyl-cholic acid (INT-777; a TGR5 agonist)-3-(2,6-dichlorophenyl)-4-(3'-carboxy-2-chlorostilben-4-yl)oxymethyl-5-isopropylisoxazole (GW4064; a FXR agonist), cyclosporin A, and irbesartan. OCA and INT-777 suppressed HBV infection in HepG2-human NTCP-C4 cells. Interestingly, INT-767 showed potent inhibition by attaching to HBV particles rather than binding to NTCP. As an entry inhibitor, INT-767 was stronger than various natural BAs. Furthermore, in chimeric mice with humanized liver, INT-767 markedly delayed the initial rise of HBsAg, HBeAg, and HBV DNA and reduced covalently closed circular DNA. The strong inhibitory effect of INT-767 may be due to the cumulative effect of its ability to inhibit the entry of HBV and to stimulate FXR downstream signaling, which affects the postentry step.

CONCLUSIONS

Our results suggest that BA derivatives, particularly INT-767, are prospective candidate anti-HBV agents. Clarifying the underlying mechanisms of BA derivatives would facilitate the development of anti-HBV agents.

Multi-center study of endoscopic revision after side-by-side metal stent placement for malignant hilar biliary obstruction

BACKGROUND

The recent development of ultra-thin delivery systems, which enable simultaneous insertion of two metal stents, has encouraged wider adoption of side-by-side (SBS) stent placement for malignant hilar biliary obstruction (MHBO). However, the management of stent occlusion after SBS placement has not been well-characterized. This study aimed to examine the outcomes of endoscopic reintervention (E-RI) after SBS placement in patients with MHBO.

METHODS

Sixty-seven patients who underwent E-RI for stent occlusion after SBS placement between 2013 and 2020 at three tertiary-care referral centers were investigated. We evaluated the technical success, clinical success, recurrent biliary obstruction (RBO), and adverse events other than RBO rates associated with E-RI. Furthermore, the factors associated with successful E-RI were also evaluated.

RESULTS

The technical success and clinical success rates were 79.1% (53/67) and 76.1% (51/67), respectively. Early adverse events other than RBO occurred in 4.5% (3/67) and late events in 3.9% (2/51). The RBO rate after E-RI was 52.9% (27/51), and the median time to RBO after E-RI was 85 days. Common bile duct (CBD) diameter (odds ratio 2.62; 95% confidence interval, 1.37-5.01; P = 0.003) and metastatic disease (odds ratio, 0.11; 95% confidence interval, 0.02-0.64; P = 0.015) were independently correlated with E-RI success in the multivariate analysis.

CONCLUSIONS

This study demonstrated that E-RI after SBS placement is technically feasible and safe, but the success rate was significantly lower in patients with narrow CBDs and metastatic diseases. These factors may be useful for the selection of the initial stenting method.

Evaluating the tissue effects of balloon-based endobiliary radiofrequency ablation in porcine bile ducts

BACKGROUND

We developed a novel balloon-based endobiliary radiofrequency ablation (RFA) system to overcome the limitations of conventional RFA in treating malignant biliary strictures. This study aimed to evaluate the histological effects of balloon-RFA in porcine bile ducts.

METHODS

Balloon-RFA of intrahepatic bile ducts from freshly resected porcine livers was performed for 60 s at 50, 60 and 70 °C. The specimens were subsequently sectioned for histological analysis and the slides were digitally scanned. Pseudo-coloring was applied based on the intensity of the ablation effect, and the area and estimated volume of ablation were measured.

RESULTS

All samples showed epithelial sloughing and coagulative necrosis, and the entire internal circumference of the bile duct was evenly ablated. Complete transmural necrosis and involvement beyond the wall were found in 0% of samples ablated at 50 °C, in 33% at 60 °C and 100% at 70 °C. The mean depth and estimated volume of the ablation areas were 1.29 mm and 353.84 mm³, 1.44 mm, and 505.54 mm³ and 1.81 mm and 702.52 mm³ at 50, 60 and 70 °C, respectively.

CONCLUSIONS

Balloon-RFA leads to sloughing of the mucosa and coagulative necrosis. Ablation depth and volume increased in proportion to target temperature.

Safety and Efficacy of Endoscopic Retrograde Cholangiopancreatography in Patients with Performance Status 4

BACKGROUND

The risk related to endoscopic retrograde cholangiopancreatography (ERCP) in patients with Eastern Cooperative Oncology Group performance status (PS) 4 is uncertain and remains a concern.

AIMS

We aimed to examine the safety and efficacy of ERCP in patients with PS4 compared to those in patients with PS0-3.

METHODS

A total of 1845 patients met the eligibility criteria for study inclusion between 2014 and 2018. The patients were divided into two groups: PS0-3 and PS4 groups. The adverse event and therapeutic success rates in each group were compared. Propensity score matching was performed to adjust for differences between the groups.

RESULTS

The therapeutic success rate was 96% in both groups. The overall adverse event rate was 6% and 10% in the PS0-3 and PS4 groups, respectively, showing no significant difference (P = 0.272). Although the rates of pancreatitis, bleeding, perforation, and cholangitis were equivalent in both groups, the pulmonary adverse event rate was significantly higher in the PS4 group (5% vs. 0.4%; P = 0.006). Severe adverse events were also significantly more frequent in the PS4 group (8% vs. 2%; P = 0.012). Multivariate analyses showed that long procedure time was a significant risk factor for adverse events in patients with PS4 (odds ratio, 10.70; 95% CI 1.30-87.70; P = 0.028).

CONCLUSIONS

Although ERCP can be performed effectively in patients with PS4, the risk of pulmonary and severe adverse events is high. Prolonged procedures should be avoided in patients with PS4.

Type IV Collagen 7S Is the Most Accurate Test For Identifying Advanced Fibrosis in NAFLD With Type 2 Diabetes

This study aimed to examine whether the diagnostic accuracy of four noninvasive tests (NITs) for detecting advanced fibrosis in nonalcoholic fatty liver disease (NAFLD) is maintained or is inferior to with or without the presence of type 2 diabetes. Overall, 874 patients with biopsy-proven NAFLD were enrolled. After propensity-score matching by age, sex, and the prevalence of dyslipidemia, 311 patients were enrolled in each group of with or without diabetes. To evaluate the effect of diabetes, we compared the diagnostic accuracy of the fibrosis-4 (FIB-4) index, the NAFLD fibrosis score (NFS), the aspartate aminotransferase to platelet ratio index (APRI), and type IV collagen 7S (COL4-7S) in patients with NAFLD with and without diabetes. The areas under the receiver operating characteristic curve (AUROC) for identifying advanced fibrosis in patients without diabetes were 0.879 for the FIB-4 index, 0.851 for the NFS, 0.862 for the APRI, and 0.883 for COL4-7S. The AUROCs in patients with diabetes were 0.790 for the FIB-4 index, 0.784 for the NFS, 0.771 for the APRI, and 0.872 for COL4-7S. The AUROC of COL4-7S was significantly larger than that of the other NITs in patients with NAFLD with diabetes than in those without diabetes. The optimal high and low cutoff points of COL4-7S were 5.9 ng/mL and 4.8 ng/mL, respectively. At the low cutoff point, the accuracy of COL4-7S was better than that of the other NITs, especially in patients with diabetes. Conclusion: COL4-7S measurement might be the best NIT for identifying advanced fibrosis in NAFLD, especially in NAFLD with diabetes.

Radial incision and cutting combined with balloon dilation for refractory pancreaticojejunostomy anastomotic strictures

Background and study aims Endoscopic balloon dilation (BD) and temporary stent placement for pancreaticojejunostomy anastomotic stricture (PJAS) achieves good short-term outcomes; however, stricture recurrences remain frequent. We examined the feasibility of performing radial incision and cutting (RIC) combined with BD for refractory PJAS.

Patients and methods Five consecutive patients with refractory PJAS who underwent RIC with BD between 2015 and 2018 were retrospectively investigated. We evaluated the technical and clinical success, adverse event (AE), and recurrence rates associated with RIC with BD.

Results In all five patients, technical and clinical success were achieved. Pancreatic stone removal was simultaneously performed in one patient. The mean procedure time was 18 minutes (range 12–23 minutes). There were no procedure-related AEs. All patients were followed for over 2 years, with a mean follow-up period of 33 months (range 24–40 months). During the follow-up period, none of the patients developed stricture recurrence and all anastomoses remained patent.

Conclusions This is the first report of RIC with BD for the treatment of refractory PJAS, showing favorable results. This combined procedure might be a useful option for treating refractory PJAS.

Characteristics of bile acid composition in high fat diet-induced nonalcoholic fatty liver disease in obese diabetic rats

Bile acid has attracted attention as a signal transmission molecule in energy metabolism. Although a high-fat diet (HFD) or obesity is known to increase hepatic fat content and alter bile acid composition, the changes in bile acid composition due to HFD or obesity remain to be elucidated. We sought to examine the bile acid composition in high fat diet-induced non-alcoholic fatty liver disease (NAFLD) in obese diabetic rats. Eight-week-old male spontaneously diabetic Torii fatty (SDTF) rats or control rats were fed an HFD. Twelve weeks post the commencement of HFD, serum and hepatic bile acid compositions and serum GLP-1 levels, which is stimulated by the secondary bile acid deoxycholic acid (DCA), were measured. The correlation between the bile acid composition and serum GLP-1 levels was also examined. While serum and hepatic levels of cholic acid (CA), a primary bile acid, tended to decrease in HFD-fed control rats, they were significantly decreased in HFD-fed SDTF rats. Hepatic CYP8B1, which plays a role in CA synthesis, the mRNA levels were significantly decreased in HFD-fed control and SDTF rats. In contrast, while serum and hepatic DCA levels were not changed in HFD-fed control rats, they were decreased in HFD-fed SDTF rats. Hepatic DCA/CA did not change in HFD-fed SDTF rats, but significantly increased in HFD-fed control rats. While serum GLP-1 levels were not changed in SDTF rats, they were significantly increased in HFD-fed control rats. Hepatic DCA/CA tended to correlate with serum GLP-1 levels, which tended to negatively correlate with the hepatic triglyceride content in SDTF rats. These results indicate that relatively increased DCA might contribute to an increase in serum GLP-1 levels, which inhibits hepatic steatosis in NAFLD.

FIB-4 First in the Diagnostic Algorithm of Metabolic-Dysfunction-Associated Fatty Liver Disease in the Era of the Global Metabodemic

The prevalence of obesity or metabolic syndrome is increasing worldwide (globally metabodemic). Approximately 25% of the adult general population is suffering from nonalcoholic fatty liver disease (NAFLD), which has become a serious health problem. In 2020, global experts suggested that the nomenclature of NAFLD should be updated to metabolic-dysfunction-associated fatty liver disease (MAFLD). Hepatic fibrosis is the most significant determinant of all cause- and liver -related mortality in MAFLD. The non-invasive test (NIT) is urgently required to evaluate hepatic fibrosis in MAFLD. The fibrosis-4 (FIB-4) index is the first triaging tool for excluding advanced fibrosis because of its accuracy, simplicity, and cheapness, especially for general physicians or endocrinologists, although the FIB-4 index has several drawbacks. Accumulating evidence has suggested that vibration-controlled transient elastography (VCTE) and the enhanced liver fibrosis (ELF) test may become useful as the second step after triaging by the FIB-4 index. The leading cause of mortality in MAFLD is cardiovascular disease (CVD), extrahepatic malignancy, and liver-related diseases. MAFLD often complicates chronic kidney disease (CKD), resulting in increased simultaneous liver kidney transplantation. The FIB-4 index could be a predictor of not only liver-related mortality and incident hepatocellular carcinoma, but also prevalent and incident CKD, CVD, and extrahepatic malignancy. Although NITs as milestones for evaluating treatment efficacy have never been established, the FIB-4 index is expected to reflect histological hepatic fibrosis after treatment in several longitudinal studies. We here review the role of the FIB-4 index in the management of MAFLD.

Evidence-based clinical practice guidelines for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis 2020

Nonalcoholic fatty liver disease (NAFLD) has become a serious public health issue not only in Western countries but also in Japan. Within the wide spectrum of NAFLD, nonalcoholic steatohepatitis (NASH) is a progressive form of disease that often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma (HCC). While a definite diagnosis of NASH requires liver biopsy to confirm the presence of hepatocyte ballooning, hepatic fibrosis is the most important prognostic factor in NAFLD. With so many NAFLD patients, it is essential to have an effective screening method for NAFLD with hepatic fibrosis. As HCC with non-viral liver disease has increased markedly in Japan, effective screening and surveillance of HCC are also urgently needed. The most common death etiology in NAFLD patients is cardiovascular disease (CVD) event. Gastroenterologists must, therefore, pay close attention to CVD when examining NAFLD patients. In the updated guidelines, we propose screening and follow-up methods for hepatic fibrosis, HCC, and CVD in NAFLD patients. Several drug trials are ongoing for NAFLD/NASH therapy, however, there is currently no specific drug therapy for NAFLD/NASH. In addition to vitamin E and thiazolidinedione derivatives, recent trials have focused on sodium glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) analogues, and effective therapies are expected to be developed. These practical guidelines for NAFLD/NASH were established by the Japanese Society of Gastroenterology in conjunction with the Japan Society of Hepatology. Clinical evidence reported internationally between 1983 and October 2018 was collected, and each clinical and background question was evaluated using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. This English summary provides the core essentials of these clinical practice guidelines, which include the definition and concept, screening systems for hepatic fibrosis, HCC and CVD, and current therapies for NAFLD/NASH in Japan.

Early Covered Self-Expandable Metal Stent Placement Is Effective for Massive Post-endoscopic Sphincterotomy Bleeding

BACKGROUND

Placement of covered self-expandable metallic stent (CSEMS) for post-endoscopic sphincterotomy (ES) bleeding achieves excellent hemostasis results. Although CSEMS placement is typically performed after failure of conventional endoscopic combination therapy, its excellent outcomes may justify earlier placement.

AIMS

We aimed to examine the efficacy of "early" CSEMS placement for massive post-ES bleeding.

METHODS

The medical records of 2750 patients who underwent ES between 2005 and 2019 were reviewed retrospectively, and 61 patients who developed massive post-ES bleeding were enrolled. These patients were divided into those who underwent early CSEMS placement (E-CSEMS group) and those who underwent conventional endoscopic combination therapy (Conventional group). The outcomes of hemostasis procedures were compared between the groups.

RESULTS

The primary success rates of endoscopic hemostasis were 100% (21/21) and 98% (39/40) in the E-CSEMS group and Conventional group, respectively, without significant differences (P = 1.000). However, in the E-CSEMS group, re-bleeding was significantly less frequent (5% vs. 31%; P = 0.023), the median hemostasis procedure time was significantly shorter (14 min vs. 26 min; P < 0.001), and transfusion after initial hemostasis treatment was less commonly required (10% vs. 38%; P = 0.034). Multivariate analyses showed that hemodialysis was associated with a significantly higher re-bleeding rate (P = 0.029), while CSEMS placement was associated with a significantly lower re-bleeding rate (P = 0.039).

CONCLUSIONS

Early CSEMS placement may be effective for improving the clinical outcomes of massive post-ES bleeding by decreasing re-bleeding and the extent of bleeding.

Screening siRNAs against host glycosylation pathways to develop novel antiviral agents against hepatitis B virus

AIM

Hepatitis B virus (HBV) relies on glycosylation for crucial functions, such as entry into host cells, proteolytic processing and protein trafficking. The aim of this study was to identify candidate molecules for the development of novel antiviral agents against HBV using an siRNA screening system targeting the host glycosylation pathway.

METHODS

HepG2.2.15.7 cells that consistently produce HBV were employed for our in vitro study. We investigated the effects of siRNAs that target 88 different host glycogenes on hepatitis B surface antigen (HBsAg) and HBV DNA secretion using the siRNA screening system.

RESULTS

We identified four glycogenes that reduced HBsAg and/or HBV DNA secretion; however, the observed results for two of them may be due to siRNA off-target effects. Knocking down ST8SIA3, a member of the sialyltransferase family, significantly reduced both HBsAg and HBV DNA secretion. Knocking down GALNT7, which transfers N-acetylgalactosamine to initiate O-linked glycosylation in the Golgi apparatus, also significantly reduced both HBsAg and HBV DNA levels.

CONCLUSIONS

These results showed that knocking down the ST8SIA3 and GALNT7 glycogenes inhibited HBsAg and HBV DNA secretion in HepG2.2.15.7 cells, indicating that the host glycosylation pathway is important for the HBV life cycle and could be a potential target for the development of novel anti-HBV agents.