Randomised trial of self-expanding metal stents versus polyethylene stents for distal malignant biliary obstruction

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Braided-type stent versus laser-cut-type stent for patients with unresectable distal malignant biliary obstruction: a randomized controlled trial

BACKGROUND AND AIMS

Fully covered self-expandable metallic stents (SEMSs) are laser-cut (L) or braided (B); however, it remains unclear which approach is more effective for distal malignant biliary obstruction (DMBO). This study compared the clinical outcomes of using L-type and B-type stents because we believe that recurrent biliary obstruction (RBO) is less likely to occur with L-type stents.

METHODS

Patients diagnosed with unresectable DMBO were randomly assigned to groups L and B in a stratified block fashion, and outcomes were compared. The primary outcome was the rate of RBO within 1 year; secondary outcomes were adverse events, clinical success rate, time to RBO (TRBO), and overall survival.

RESULTS

Of the 60 enrolled participants, 56 (group L, n = 27; group B, n = 29) were included. The rates of RBO within 1 year were 44.4% and 17.2% in groups L and B, respectively (odds ratio, 2.57; 95% confidence interval [CI], 1.045-6.353). Early adverse events, which improved with conservative treatment, included pancreatitis (n = 4) in group L and pancreatitis (n = 3) and cholecystitis (n = 1) in group B (P = .913). The median TRBO (220 days [95% CI, 56-272] vs 418 days [95% CI, 232-454]) was significantly longer in group B than in group L (log-rank test, P = .0118). The median overall survival (group L, 158 days; group B, 204 days) after stenting was not significantly different between groups (P = .8544).

CONCLUSIONS

In the setting of DMBO, B-type stents are associated with less recurrent obstruction than L-type stents, although there was no difference in safety. (UMIN Clinical Trials Registry number: UMIN000027239.).

A novel fully covered metal stent for unresectable malignant distal biliary obstruction: results of a multicenter prospective study

BACKGROUND/AIMS

Endoscopic self-expandable metal stent (SEMS) placement is currently the standard technique for treating unresectable malignant distal biliary obstructions (MDBO). Therefore, covered SEMS with longer stent patency and fewer migrations are required. This study aimed to assess the clinical performance of a novel, fully covered SEMS for unresectable MDBO.

METHODS

This was a multicenter single-arm prospective study. The primary outcome was a non-obstruction rate at 6 months. The secondary outcomes were overall survival (OS), recurrent biliary obstruction (RBO), time to RBO (TRBO), technical and clinical success, and adverse events.

RESULTS

A total of 73 patients were enrolled in this study. The non-obstruction rate at 6 months was 61%. The median OS and TRBO were 233 and 216 days, respectively. The technical and clinical success rates were 100% and 97%, respectively. Furthermore, the rate of occurrence of RBO and adverse events was 49% and 21%, respectively. The length of bile duct stenosis (<2.2 cm) was the only significant risk factor for stent migration.

CONCLUSIONS

The non-obstruction rate of a novel fully covered SEMS for MDBO is comparable to that reported earlier but shorter than expected. Short bile duct stenosis is a significant risk factor for stent migration.

Comparison of covered self-expandable metallic stents with 12-mm and 10-mm diameters for unresectable malignant distal biliary obstructions: a prospective randomized trial

BACKGROUND AND AIMS

Covered self-expandable metallic stents have longer patency than uncovered self-expandable metallic stents for unresectable malignant distal biliary obstruction because of the prevention of tumor ingrowth, and they are removable during reintervention. One main cause of recurrent biliary obstruction in covered self-expandable metallic stents is sludge formation, which can be prevented by using large-bore stents. We evaluated the treatment results of 12-mm and 10-mm covered self-expandable metallic stents for unresectable malignant distal biliary obstructions using a randomized controlled trial.

METHODS

This study was conducted between May 2016 and January 2019 and included 81 consecutive patients with unresectable malignant distal biliary obstruction. The primary endpoint was the rate of nonrecurrent biliary obstruction at 6 months after stent placement.

RESULTS

The primary endpoint in the 12-mm group was significantly higher than that in the 10-mm group (P = .0369). Therefore, the median time to recurrent biliary obstruction was 172 days in the 12-mm group and 120 days in the 10-mm group. The median time to recurrent biliary obstruction in the 12-mm group was significantly longer than that in the 10-mm group (P = .0168). Using the 12-mm covered self-expandable metallic stents and receiving chemotherapy were factors affecting the rate of recurrent biliary obstruction in the multivariate analysis.

CONCLUSIONS

The 12-mm covered self-expandable metallic stents provide a longer time to recurrent biliary obstruction than do 10-mm covered self-expandable metallic stents for managing unresectable malignant distal biliary obstruction. (Clinical trial registration number: UMIN000016911.).

Anti-fibrotic and anti-stricture effects of biodegradable biliary stents braided with dexamethasone-impregnated sheath/core structured monofilaments

Endoscopic biliary stent insertion has been widely used for the treatment of benign biliary stricture (BBS). Thus, the development of stent materials in the perspectives of structure, mechanical properties, and biocompatibility has been also studied. However, conventional metal and plastic stents have several disadvantages, such as repeated procedures to remove or exchange them, dislodgment, restenosis, biocompatibility, and poor mechanical properties. Sustainable effectiveness, attenuation and prevention of fibrosis, and biocompatibility are key factors for the clinical application of stents to BBS treatment. In addition, loading drugs could show synergistic effects with stents' own performance. We developed a dexamethasone-eluting biodegradable stent (DBS) consisting of a sheath/core structure with outstanding mechanical properties and sustained release of dexamethasone, which maintained its functions in a BBS duct over 12 weeks in a swine model. The insertion of our DBS not only expanded BBS areas but also healed secondary ulcers as a result of the attenuation of fibrosis. After 16 weeks from the insertion, BBS areas were totally improved, and the DBS was degraded and thoroughly disappeared without re-intervention for stent removal. Our DBS would be an effective clinical tool for non-vascular diseases. STATEMENT OF SIGNIFICANCE: This study describes the insertion of a drug-eluting biodegradable stent (DBS) into the bile duct. The sheath/core structure of DBS confers substantial durability and a sustained drug release profile. Drug released from the DBS exhibited anti-fibrotic effects without inflammatory responses in both in vitro and in vivo experiments. The DBS maintained its function over 12 weeks after insertion into the common bile duct, expanding benign biliary stricture (BBS) and reducing inflammation to heal secondary ulcers in a swine BBS model. After 16 weeks from the DBS insertion, the DBS thoroughly disappeared without re-intervention for stent removal, resulting in totally improved BBS areas. Our findings not only spotlight the understanding of the sheath/core structure of the biodegradable stent, but also pave the way for the further application for non-vascular diseases.

ASO Practice Guidelines Series: Management of Resectable, Borderline Resectable, and Locally Advanced Pancreas Cancer

Pancreatic adenocarcinoma is an aggressive disease marked by high rates of both local and distant failure. In the minority of patients with potentially resectable disease, multimodal treatment paradigms have allowed for prolonged survival in an increasingly larger pool of well-selected patients. Therefore, it is critical for surgical oncologists to be abreast of current guideline recommendations for both surgical management and multimodal therapy for pancreas cancer. We discuss these guidelines, as well as the underlying data supporting these positions, to offer surgical oncologists a framework for managing patients with pancreatic adenocarcinoma.

Malignant Acute Colonic Obstruction: Multidisciplinary Approach for Endoscopic Management

Patients presenting with acute colonic obstruction are usually evaluated in the emergency department and multiple specialties are involved in the patients' management. Pre-treatment evaluation is essential in order to establish the correct endoscopic indication for stent implantation. Contrast-enhanced imaging could allow the exclusion of benign causes of colonic obstruction and evaluation of the length of malignant stricture. Endoscopic stenting is the gold standard of treatment for palliative indications whereas there are still concerns about its use as a bridge to surgery. Different meta-analyses showed that stenting as a bridge to surgery improves short-term surgical outcomes but has no role in improving long-term outcomes. Multidisciplinary evaluation is also essential in patients that may be started on or are currently receiving antiangiogenic agents because endoscopic stenting may increase the risk of perforation. Evidence in the literature is weak and based on retrospective data. Here we report on how to correctly evaluate a patient with acute colonic malignant obstruction in collaboration with other essential specialists including a radiologist, surgeon and oncologist, and how to optimize the technique of endoscopic stenting.

Pilot study on cultural and metagenomic analysis of bile and biliary stentslead to unveiling the key players in stent occlusion

Endoscopic Retrograde Cholangio-Pancreatography (ERCP) with biliary stenting is a minimally invasive medical procedure employed to address both malignant and benign obstructions within the biliary tract. Benign biliary strictures (BBSs), typically arising from surgical interventions such as liver transplants and cholecystectomy, as well as chronic inflammatory conditions, present a common clinical challenge. The current gold standard for treating BBSs involves the periodic insertion of plastic stents at intervals of 3-4 months, spanning a course of approximately one year. Unfortunately, stent occlusion emerges as a prevalent issue within this treatment paradigm, leading to the recurrence of symptoms and necessitating repeated ERCPs. In response to this clinical concern, we initiated a pilot study, delving into the microbial composition present in bile and on the inner surfaces of plastic stents. This investigation encompassed 22 patients afflicted by BBSs who had previously undergone ERCP with plastic stent placement. Our preliminary findings offered promising insights into the microbial culprits behind stent occlusion, with Enterobacter and Lactobacillus spp. standing out as prominent bacterial species known for their biofilm-forming tendencies on stent surfaces. These revelations hold promise for potential interventions, including targeted antimicrobial therapies aimed at curtailing bacterial growth on stents and the development of advanced stent materials boasting anti-biofilm properties.

Adverse events of self-expandable metal stent placement for malignant distal biliary obstruction: a large multicenter study

BACKGROUND AND AIMS

Endoscopic placement of self-expandable metal stents (SEMSs) for malignant distal biliary obstruction (MDBO) may be accompanied by several types of adverse events. The present study analyzed the adverse events occurring after SEMS placement for MDBO.

METHODS

The present study retrospectively investigated the incidence and types of adverse events in patients who underwent SEMS placement for MDBO between April 2018 and March 2021 at 26 hospitals. Risk factors for acute pancreatitis, cholecystitis, and recurrent biliary obstruction (RBO) were evaluated by univariate and multivariate analyses.

RESULTS

Of the 1425 patients implanted with SEMSs for MDBO, 228 (16.0%) and 393 (27.6%) experienced early adverse events and RBO, respectively. Pancreatic duct without tumor involvement (P = .023), intact papilla (P = .025), and SEMS placement across the papilla (P = .037) were independent risk factors for acute pancreatitis. Tumor involvement in the orifice of the cystic duct was an independent risk factor for cholecystitis (P < .001). Use of fully and partially covered SEMSs was an independent risk factor for food impaction and/or sludge. Use of fully covered SEMSs was an independent risk factor for stent migration. Use of uncovered SEMSs and laser-cut SEMSs was an independent risk factor for tumor ingrowth.

CONCLUSIONS

Pancreatic duct without tumor involvement, intact papilla, and SEMS placement across the papilla were independent risk factors for acute pancreatitis, and tumor involvement in the orifice of the cystic duct was an independent risk factor for cholecystitis. The risk factors for food impaction and/or sludge, stent migration, and tumor ingrowth differed among types of SEMSs.

Sems Sensibility: Biliary Stent Migration into the Oesophagus

Endoprostheses are commonly used in the treatment of biliary and pancreatic disorders. Fully-covered metal stents are intended for the palliation of malignant strictures in the biliary tree. We report a case of a patient affected by cancer of the pancreas who was treated with a proximal metallic biliary stent. The stent migrated to the oesophagus and was endoscopically removed. Proximal migration, although rare, should be kept in mind as a potential complication of the procedure.

Covered self-expandable metallic stents versus plastic stents for endoscopic ultrasound-guided hepaticogastrostomy in patients with malignant biliary obstruction

BACKGROUND/AIMS

Covered self-expandable metallic stents (cSEMS) have become popular for endoscopic ultrasound-guided hepaticogastrostomy with transmural stenting (EUS-HGS). We compared the time to recurrent biliary obstruction (TRBO), complications, and reintervention rates between EUS-HGS using plastic stent (PS) and cSEMS in patients with unresectable malignancies at multicenter institutions in Japan.

METHODS

Patients with unresectable malignant biliary obstruction who underwent EUS-HGS between April 2015 and July 2020 at any of the six participating facilities were enrolled. Primary endpoint: TRBO; secondary endpoints: rate of complications other than recurrent biliary obstruction and technical success rate of reintervention were evaluated.

RESULTS

PS and cSEMS were used for EUS-HGS in 109 and 43 patients, respectively. The TRBO was significantly longer in the cSEMS group than in the PS group (646 vs. 202 days). Multivariate analysis identified two independent factors associated with a favorable TRBO: combined EUS-guided antegrade stenting with EUS-HGS and the use of cSEMS. No significant difference was observed in the rate of complications other than recurrent biliary obstruction between the two groups. The technical success rate of reintervention was 85.7% for PS and 100% for cSEMS (p=0.309).

CONCLUSION

cSEMS might be a better option for EUS-HGS in patients with unresectable malignancies, given the longer TRBO.

Risk factors for early and late cholecystitis after covered metal stent placement for distal biliary obstruction

BACKGROUND

Cholecystitis is a major adverse event after self-expandable metallic stent placement for distal biliary obstruction (DBO). Covered self-expandable metallic stent (CSEMS) is being increasingly used, but few studies have investigated risk factors for cholecystitis limited to CSEMS. The present study aimed to identify risk factors for cholecystitis after CSEMS.

METHODS

Patients who underwent initial CSEMS placement for DBO between November 2014 and September 2021 were enrolled and followed-up until death, recurrent biliary obstruction, cholecystitis, or until March 2022. Cholecystitis within 30 days of CSEMS was defined as early cholecystitis and after 30 days as late cholecystitis.

RESULTS

Cholecystitis occurred in 51 of 339 patients (15%) after CSEMS. Forty-one patients (80.4%) had early cholecystitis, and 10 (19.6%) had late cholecystitis. Multivariate logistic regression analysis revealed that the maximum diameter of the common bile duct (CBD) (per 1 mm increase) (odds ratio [OR]: 0.87; 95% confidence interval [CI]: 0.76-1.00; p = .044), gallbladder stones (OR: 3.63; 95% CI: 1.62-8.10; p = .002), and tumor involvement in the cystic duct (CD) (OR: 4.87; 95% CI: 2.16-11.00; p < .001) were significant independent risk factors associated with early cholecystitis. No significant risk factors were identified for late cholecystitis.

CONCLUSIONS

A smaller CBD diameter, gallbladder stones, and tumor involvement in the CD were identified as risk factors for early cholecystitis development after CSEMS.

Uncovered versus fully covered self-expandable metal stents for the management of distal malignant biliary obstruction

BACKGROUND AND AIM

Self-expandable metal stents (SEMSs) are widely used for palliation of distal malignant biliary obstruction (dMBO). However, previous studies comparing the outcomes between uncovered SEMSs (UCSEMSs) and fully covered SEMSs (FCSEMSs) report conflicting results. This large cohort study aimed to compare the clinical outcomes between UCSEMSs and FCSEMSs for dMBO.

METHODS

A retrospective cohort study was performed in patients with dMBO who underwent either UCSEMS or FCSEMS placement between May 2017 and May 2021. Primary outcomes were rates of clinical success, adverse events (AEs), and unplanned endoscopic reintervention. Secondary outcomes were types of AEs, intervention-free stent patency, and management and outcomes of stent occlusion.

RESULTS

The cohort included 454 patients (364 in the UCSEMS group and 90 in the FCSEMS group). Median follow-up duration was 9.6 months and was similar between the 2 groups. Use of UCSEMSs and FCSEMSs had comparable clinical success (P = .250). However, use of UCSEMSs had significantly higher rates of AEs (33.5% vs 21.1%; P = .023) and unplanned endoscopic reintervention (27.0% vs 11.1%; P = .002). UCSEMSs had a higher rate of stent occlusion (26.9% vs 8.9%; P < .001) and shorter median time to stent occlusion (4.4 months vs 10.7 months; P = .002). Stent reintervention-free survival was higher in the FCSEMS group. FCSEMSs had a significantly higher rate of stent migration (7.8% vs 1.1%; P < .001), but patients in the FCSEMS group had similar rates of cholecystitis (.3% vs 1.1%; P = .872) and post-ERCP pancreatitis (6.3% vs 6.6%; P = .90). When UCSEMSs did occlude, placement of a coaxial plastic stent had a higher rate of stent reocclusion compared with coaxial SEMS placement (46.7% vs 19.7%; P = .007).

CONCLUSION

FCSEMSs should be considered for the palliation of dMBO because of lower rates of AEs, longer patency rates, and lower rates of unplanned endoscopic intervention.

Delayed Hemobilia: A Rare Case of Biliary Bleeding One Year After Metallic Stent Placement

Hemobilia is a rare cause of upper GI bleed. This case report discusses hemobilia caused as a delayed complication of self-expanding metallic stent (SEMS) placement in a 65-year-old male. Our patient had a history of hepatitis C and an unresectable hepatocellular carcinoma, treated with chemotherapy and radiation therapy, which caused obstructive jaundice, which in turn led to the placement of SEMS. This case highlights the challenges in managing late-onset biliary bleeding, especially in patients with underlying malignancies. Detection of bleeding in a timely manner is crucial in devising the treatment plan. Angiographic occlusion is the first line of management to stop the bleed followed by definitive surgery or stent revision. Severe complications can occur in patients with poor general health. This case report addresses the importance of monitoring the patient and the need for collaborative efforts across specialties in managing complex cases. Despite the best efforts of the medical team, this case serves as a reminder of the complex and twisted nature of medical conditions, telling us the importance of developing suitable treatment strategies for each patient's needs and healthcare requirements.

Comparable Efficacy of Laser-Cut and Braided Self Expanding Metallic Biliary Stent: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

In patients with unresectable malignant biliary obstruction (MBO), endoscopic biliary drainage is the treatment of choice. Self-expanding metallic stents (SEMS) are mainly used for this purpose, and data is limited on the comparative outcomes of laser-cut versus braided SEMS. Herein, we performed the first systematic review and meta-analysis to study the effectiveness and safety of braided and laser-cut SEMS in MBO.

METHODS

Multiple databases, including Medline, Scopus, and Embase, were searched (in May 2022) using specific terms for studies evaluating the outcomes of braided and laser-cut SEMS in MBO. Outcomes of interest were technical and clinical success, recurrent biliary obstruction, and adverse events. Standard meta-analysis methods were employed using the random-effects model. I2% heterogeneity was used to assess the heterogeneity.

RESULTS

Seven studies were included in the final analysis. (Laser-cut: 271 patients, 46% females, mean age 70 years; and braided: 282 patients, 47% females, mean age 72 years). The pooled rate of technical success and clinical success with laser-cut SEMS was 99% (95% CI [95-99; I2 = 0%]), 86% [60-96; I2 = 74%], and 98% [96-99; I2 = 0%], 89% [74-95; I2 = 78%] with braided. The pooled rate of recurrent biliary obstruction with laser-cut SEMS was 26% [14-43; I2 = 88%] and 12% [5-27; I2 = 56%) with braided. Pooled total adverse events were 11% [5-21; I2 = 77%] in laser-cut and 12% [6-24; I2 = 63%] in braided.

CONCLUSION

Our meta-analysis demonstrates similar clinical outcomes with laser-cut and braided SEMS in MBO. Given the comparable performance, a cost-effectiveness analysis might help in choosing one type versus another in patients with MBO.

Prophylactic endoscopic gallbladder stent placement for cholecystitis after covered metal stent placement for distal biliary obstruction (with video)

BACKGROUND AND AIMS

Acute cholecystitis is occasionally observed after biliary drainage using a covered self-expandable metal stent (CSEMS) for distal biliary obstruction (DBO). Gallbladder drainage before CSEMS placement may reduce cholecystitis. This study aimed to examine the preventive effect of endoscopic gallbladder stent placement (EGBS) on cholecystitis with CSEMSs.

METHODS

We retrospectively analyzed patients with DBO who underwent CSEMS placement across the orifice of the cystic duct between November 2014 and October 2021 and were negative for cholecystitis on biliary drainage. Prophylactic EGBS was attempted before CSEMS placement. The incidence of cholecystitis was compared between patients with and without EGBS.

RESULTS

In total, 286 patients (128 men; median age, 75 years) were included in this study. EGBS was attempted in 32 patients before CSEMS placement, and technical success was achieved in 24 patients (75%). Adverse events were noted in 3 patients (9.4%; penetration of cystic duct in 1 and acute pancreatitis in 2). The cumulative incidence of cholecystitis was significantly lower in patients with EGBS than in those without EGBS (1 [4.2%] vs 56 [21.4%], P = .045). In multivariable analysis, EGBS was a significant protective factor against cholecystitis (hazard ratio, .11; 95% confidence interval, .01-.79; P = .028).

CONCLUSIONS

Although the transpapillary approach to the gallbladder is not easy for patients with DBO, EGBS is effective in preventing cholecystitis associated with CSEMS placement.

Efficacy of Fully Covered Self-Expandable Metal Stents for Distal Biliary Obstruction Caused by Pancreatic Ductal Adenocarcinoma: Primary Metal Stent vs. Metal Stent following Plastic Stent

Fully covered self-expandable metallic stents (FCSEMSs) are inserted in patients with unresectable pancreatic ductal adenocarcinoma (PDAC) to resolve malignant distal bile duct obstructions. Some patients receive FCSEMSs during primary endoscopic retrograde cholangiopancreatography (ERCP), and others receive FCSEMSs during a later session, after the placement of a plastic stent. We aimed to evaluate the efficacy of FCSEMSs for primary use or following plastic stent placement. A total of 159 patients with pancreatic adenocarcinoma (m:f, 102:57) who had achieved clinical success underwent ERCP with the placement of FCSEMSs for palliation of obstructive jaundice. One-hundred and three patients had received FCSEMSs in a first ERCP, and 56 had received FCSEMSs after prior plastic stenting. Twenty-two patients in the primary metal stent group and 18 in the prior plastic stent group had recurrent biliary obstruction (RBO). The RBO rates and self-expandable metal stent patency duration did not differ between the two groups. An FCSEMS longer than 6 cm was identified as a risk factor for RBO in patients with PDAC. Thus, choosing an appropriate FCSEMS length is an important factor in preventing FCSEMS dysfunction in patients with PDAC with malignant distal bile-duct obstruction.

Novel anti-reflux biliary metal stent with a distal tapered end for distal malignant biliary obstruction: a feasibility study

Background and study aims  We developed a self-expandable metallic stent (SEMS) with a distal tapered end to reproduce the physiological bile flow with a pressure gradient due to the difference in the diameter. We aimed to evaluate the safety and efficacy of the newly developed distal tapered covered metal stent (TMS) for distal malignant biliary obstruction (DMBO). Patients and methods  This single-center, prospective, single-arm study was conducted in patients with DMBO. The primary endpoint was time to recurrent biliary obstruction (TRBO), and the secondary endpoints were the survival time and incidence of adverse events (AEs). Results  Thirty-five patients (15 men, 20 women; median age, 81 years [range: 53-92]) were enrolled between December 2017 and December 2019. The primary diseases were pancreatic head cancer in 25 cases, bile duct cancer in eight cases, and ampullary cancer in two cases. TMS was successfully placed in all cases. Acute cholecystitis occurred as an early AE (within 30 days) in two cases (5.7 %). The median TRBO was 503 days, median survival time was 239 days. RBO was observed in 10 cases (28.6 %), and the causes were distal migration in six cases, proximal migration in two cases, biliary sludge in one case, and tumor overgrowth in one case. Conclusions  Endoscopic placement of the newly developed TMS in patients with DMBO is technically feasible and safe, and the TRBO was remarkably long. The anti-reflux mechanism based on the difference in diameter may be effective, and a randomized controlled trial with a conventional SEMS is required.

A Systematic Review of Endoscopic Treatments for Concomitant Malignant Biliary Obstruction and Malignant Gastric Outlet Obstruction and the Outstanding Role of Endoscopic Ultrasound-Guided Therapies

BACKGROUND

The treatments for cancer palliation in patients with concomitant malignant biliary obstruction (MBO) and gastric outlet obstruction (MGOO) are still under investigation due to the lack of evidence available in the medical literature. We performed a systematic search and critical review to investigate efficacy and safety among patients with MBO and MGOO undergoing both endoscopic ultrasound-guided biliary drainage (EUS-BD) and MGOO endoscopic treatment.

METHODS

A systematic literature search was performed in PubMed, MEDLINE, EMBASE, and the Cochrane Library. EUS-BD included both transduodenal and transgastric techniques. Treatment of MGOO included duodenal stenting or EUS-GEA (gastroenteroanastomosis). Outcomes of interest were technical success, clinical success, and rate of adverse events (AEs) in patients undergoing double treatment in the same session or within one week.

RESULTS

11 studies were included in the systematic review for a total number of 337 patients, 150 of whom had concurrent MBO and MGOO treatment, fulfilling the time criteria. MGOO was treated by duodenal stenting (self-expandable metal stents) in 10 studies, and in one study by EUS-GEA. EUS-BD had a mean technical success of 96.4% (CI 95%, 92.18-98.99) and a mean clinical success of 84.96% (CI 95%, 67.99-96.26). The average frequency of AEs for EUS-BD was 28.73% (CI 95%, 9.12-48.33). Clinical success for duodenal stenting was 90% vs. 100% for EUS-GEA.

CONCLUSIONS

EUS-BD could become the preferred drainage in the case of double endoscopic treatment of concomitant MBO and MGOO in the near future, with the promising EUS-GEA becoming a valid option for MGOO treatment in these patients.

Safety and efficacy of self-expandable metallic stent combined with 125I brachytherapy for the treatment of malignant obstructive jaundice

BACKGROUND

Several previous studies demonstrated that the combination of self-expandable metallic stents (SEMS) and ¹²⁵I seed implantation might prolong stent patency and obtain survival benefits for malignant obstructive jaundice (MOJ) patients. However, these studies rarely mentioned a comparison between CT-guided intratumoral ¹²⁵I seed implantation and intraluminal ¹²⁵I seed strand insertion combined with stenting for the management of MOJ. This study aimed to further evaluate the safety and efficacy of SEMS combined with ¹²⁵I brachytherapy in the management of unresectable MOJ.

METHODS

Fifty-nine patients with unresectable MOJ were retrospectively included from March 2018 to June 2021. The main therapeutic outcomes were evaluated in terms of stent patency, and overall survival. Cumulative stent patency and overall survival rates were calculated by Kaplan-Meier survival analysis. Both clinical and treatment factors associated with survival were analyzed.

RESULTS

Technical success was achieved in all patients. The clinical success rate was 94% (32/34) in the seeds group and 92% (23/25) in the control group, no significant difference was found (p =1.000). The median duration of stent patency was significantly longer in the ¹²⁵I brachytherapy group compared with the control group (289 days vs. 88 days, respectively, p =0.001). The ¹²⁵I brachytherapy group demonstrated a significantly better median overall survival rate than the control group (221 days vs. 78 days, respectively, p =0.001). In multivariate analysis, stents with ¹²⁵I brachytherapy (p =0.004) was a significant favorable prognostic factor that affected patient survival. No significant difference was observed between CT-guided ¹²⁵I seed implantation and ¹²⁵I seed strand insertion in stent patency (p =0.268), and overall survival (p =0.483).

CONCLUSION

SEMS combined with ¹²⁵I brachytherapy is safe and effective for treating MOJ. ¹²⁵I brachytherapy may help to maintain stent patency and prolong overall survival. There was no significant difference between CT-guided ¹²⁵I seed implantation with SEMS and ¹²⁵I seed strand insertion with SEMS in stent patency and overall survival.

Effect of ursodeoxycholic acid after self-expandable metal stent placement in malignant distal biliary obstruction: a propensity score-matched cohort analysis

BACKGROUND AND AIMS

Sludge occlusion is a primary reason for recurrent biliary obstruction (RBO) after self-expandable metallic stent (SEMS) placement. However, the efficacy of ursodeoxycholic acid (UDCA) for SEMS occlusion remains unexplored to date. This study aimed to evaluate the efficacy of UDCA after SEMS placement for malignant distal biliary obstruction (MDBO).

METHODS

Three hundred fifty-four patients were included, of which 60 received UDCA. Additionally, we conducted a propensity score-matched cohort analysis on 110 patients with SEMS placement for MDBO to reduce selection bias. Patients were categorized into 2 groups of 55 each, based on whether they received UDCA. In the UDCA group, the treatment was administered for more than a month. The primary endpoint was the time to RBO (TRBO) after SEMS placement. The secondary endpoint was to evaluate SEMS occlusion rate and early adverse events (AEs).

RESULTS

The cumulative SEMS occlusion rate was 41.8% and 18.2% in the groups with and without UDCA, respectively (P = .0119). Median TRBO was significantly longer in the control group than in the UDCA group (528 vs 154 days, P = .0381). In the multivariate analysis, UDCA administration was identified as the independent risk factor for reducing TRBO (hazard ratio, 2.28; 95% confidence interval, 1.06-4.88; P = .0348). The overall early AE rate showed insignificant differences between groups.

CONCLUSIONS

Administering UDCA after SEMS placement was not efficacious for prolonging the TRBO in MDBO. Moreover, administering UDCA beyond a month might increase the risk of stent sludge occlusion. (Clinical trial registration number: UMIN000046862.).

In-stent radiofrequency ablation with uncovered metal stent placement for tumor ingrowth/overgrowth causing self-expandable metal stent occlusion in distal malignant biliary obstruction: multicenter propensity score-matched study

BACKGROUND AND AIMS

In patients with unresectable malignant biliary obstruction (MBO), endoscopic drainage with a self-expandable metal stent (SEMS) is a well-established treatment, but stent patency is limited. This study aimed to evaluate the efficacy of in-stent radiofrequency ablation (IS-RFA) followed by uncovered SEMS placement for the management of occluded SEMSs.

METHODS

From 2016 to 2020, 48 patients with recurrent biliary obstruction due to tumor ingrowth or overgrowth after SEMS placement for pancreatobiliary cancer in 3 tertiary hospitals were analyzed. For distal MBO, patients in the RFA group were treated with IS-RFA and uncovered SEMS placement, and those in the control group were treated with uncovered SEMS placement alone. Patients in both groups were matched on the basis of propensity scores in a 1:1 ratio.

RESULTS

The median time to recurrent biliary obstruction (TRBO) was 117 days in the RFA group and 82.5 days in the control group (P = .029). No significant differences in median overall survival were detected between the 2 groups (170 days vs 72 days; P = .902). No significant adverse events were reported after the second SEMS placement in either group, but 2 cases of mild cholangitis were reported in the control group. Ablation was interrupted in 5 patients (35.7%) of the RFA group owing to in-stent contact, but sufficient ablative energy was delivered in the majority of the patients (92.9%) after IS-RFA was repeated in the same session.

CONCLUSIONS

IS-RFA followed by an uncovered SEMS is safe and feasible and may improve TRBO as a stent revision for occluded SEMSs in pancreatobiliary cancer.

Comparison of Bilateral and Trisegment Drainage in Patients with High-Grade Hilar Malignant Biliary Obstruction: A Multicenter Retrospective Study

Background/Aims

Bilateral endoscopic drainage with self-expanding metallic stent (SEMS) can be used to effectively manage hilar malignant biliary obstruction. However, the benefits of using a trisegment drainage method remain unknown.

Methods

This study retrospectively reviewed the data of 125 patients with Bismuth type IIIa or IV unresectable malignant strictures who underwent bilateral endoscopic drainage using SEMSs at four tertiary centers. The patients were divided into the bilateral and trisegment drainage groups for comparison. The primary endpoint was stent patency and the secondary endpoints were technical success, technical and clinical success of reintervention, and overall survival.

Results

The technical success rates of the bilateral and trisegment drainage groups were 95% (34/36) and 90% (80/89) (p=0.41), respectively, with median stent patency durations of 226 and 170 days (p=0.26), respectively. Although the technical success of reintervention was not significantly different between the two groups (p=0.51), the clinical success rate of reintrvention was significantly higher in the trisegment drainage group (73% [11/15] vs 96% [47/49], p=0.009). The median survival times were 324 and 323 days in the bilateral and trisegment drainage groups, respectively (p=0.72). Multivariate Cox hazards model revealed no stent patency-associated factor; however, chemotherapy was associated with longer survival.

Conclusions

Although no significant difference was noted with respect to stent patency, significantly higher clinical success rates were achieved with reintervention using the trisegment drainage method than using the bilateral drainage method alone.

A case of delayed pancreatic fistula after covered self-expandable metallic stent deployment for pancreatic head cancer

A 69-year-old man was referred to our hospital with obstructive jaundice. A tumor with poor contrast enhancement was found in the pancreatic head, but there was no evidence of pancreatic atrophy, irregular stenosis, or dilation of the main pancreatic duct. He was diagnosed with borderline resectable pancreatic cancer with distal malignant biliary obstruction. After plastic stent placement, serum bilirubin levels improved, and chemotherapy was started. However, he developed cholangitis; thus, the plastic stent was replaced with a covered self-expandable metallic stent. He subsequently developed a delayed pancreatic fistula due to main pancreatic duct disruption. An endoscopic nasopancreatic duct drainage tube was placed to bridge the main pancreatic duct disruption after removing the covered self-expandable metallic stent. In addition, endoscopic ultrasound-guided transmural drainage was performed for the infected fluid collection caused by the pancreatic fistula, and the clinical symptoms quickly improved. This case presents the possibility of a delayed pancreatic fistula due to self-expandable metallic stent deployment. The need for considering such delayed complications when placing self-expanding metallic stents is highlighted.

Efficacy of a novel self-expandable metal stent with dumbbell-shaped flare ends for distal biliary obstruction due to unresectable pancreatic cancer

This study aimed to evaluate the efficacy of a novel fully covered self-expandable metal stent (SEMS) with dumbbell-shaped flare ends for the palliation of distal biliary obstruction (DBO) due to unresectable pancreatic cancer (UPC). Patients with DBO due to UPC who received the novel HILZO fully covered stent (HFS), the WALLFLEX partially covered stent (WPS) or fully covered stent (WFS) were analyzed. The incidence of recurrent biliary obstruction (RBO), time to RBO (TRBO), and the incidence of complications were compared among the three SEMS groups. Eighty-four patients (HFS, n = 36; WPS, n = 20; WFS, n = 28) were included. The incidence of RBO was low in the HFS group (versus the WPS and WFS group, p = 0.033 and 0.023, respectively). TRBO in the HFS group was longer than that in the WFS group (p = 0.049). Placement of the HFS was an independent factor for long TRBO in multivariable analysis (p = 0.040). The incidence of pancreatitis and cholecystitis in the HFS group was low (one for each). It is recommended to use the HFS for the palliation of DBO due to UPC from the viewpoint of the low incidence of RBO and complications.

Acetylsalicylic acid for metal stent in malignant distal common bile duct obstruction: A randomized controlled trial

BACKGROUND

Endoscopic biliary drainage is the treatment of choice for patients with malignant distal common bile duct obstruction. Self-expandable metal stents have clinical advantages including an increased duration of patency that may be prolonged by acetylsalicylic acid (ASA) use. The aim of this study was to investigate whether ASA had a positive effect on the patency of self-expandable metal stents compared with placebo.

METHODS

This prospective, multicenter, double-blinded, and randomized placebo-controlled trial was conducted from October 2017 to May 2020 in Korea. Patients who underwent palliative endoscopic biliary drainage with self-expandable metal stents for malignant distal bile duct obstruction were enrolled, and allocated to ASA treatment or placebo. The study outcomes were the rate of stent dysfunction at 6 months, duration of stent patency, risk factors for stent dysfunction, and any adverse events.

RESULTS

Interim analysis included 24 and 28 patients in the ASA and placebo groups, respectively. There was no significant difference between the ASA and placebo groups in stent dysfunction (25.0% vs. 20.7%, P = 0.761) or the duration of stent patency (150.97 ± 10.55 vs. 158.07 ± 8.70 days, P = 0.497). Six patients experienced suspected ASA-related adverse events, and there was one lethal case.

CONCLUSIONS

ASA did not prolong stent patency. This study was terminated early because of the possibility of serious adverse events related to ASA treatment of these patients receiving palliative care.

Layered Double Hydroxide-Based Micro "Chemical Factory" with Arsenic Processing and Screening Functions on Nitinol for Gallbladder Cancer Treatment

Gallbladder cancer is a common malignant tumor of the biliary system with a high fatality rate. Nitinol (Ni-Ti) stents, a standard treatment for prolonging patients' lives, are susceptible to reocclusion and cannot inhibit tumor recurrence because they lack antitumor and antibacterial activity. Herein, an arsenic-loaded layered double-hydroxide film is constructed on Ni-Ti, forming a micro "chemical factory." The LDH plays the role of a "processer" which absorbs highly toxic trivalent arsenic (As(III)) and processes it into lowly toxic pentavalent arsenic (As(V)). It also acts as a "quality-inspector," confining As(III) in the interlayer and releasing only As(V) (the finished product) to the outside. This control mechanism minimizes the toxicity during contact with normal tissue. The acidic microenvironment and overexpression of glutathione in tumor tissues not only accelerates the release of arsenic from the platform but also triggers the in situ transformation of arsenic from lowly toxic As(V) to highly toxic As(III), exerting a strong arsenic-mediated antineoplastic effect. Such a microenvironment-responsive "chemical factory" with arsenic processing and screening functions is expected to prevent tumor overgrowth, metastasis, and bacterial infection and provide new insights into the design of Ni-Ti drug-eluting stents for gallbladder cancer treatment.

Comparison of outcomes between secondary fully covered and uncovered self-expandable metal stents in the treatment of recurrent biliary obstruction of pancreatic cancer

BACKGROUND

The overall survival (OS) of pancreatic cancer (PC) has been prolonged by advances in chemotherapy, and the number of cases of recurrent biliary obstruction (RBO) after self-expandable metal stent (SEMS) placement is expected to increase. We herein compared outcomes between secondary fully covered SEMS (FC) and uncovered SEMS (UC) for RBO of PC with FC placed as the 1st SEMS.

METHODS

Between May 2010 and March 2021, 62 PC patients who underwent SEMS exchange to FC (n = 34) or UC (n = 28) for RBO were retrospectively analyzed. Patient characteristics, OS, time to RBO (TRBO), and stent-related adverse events were compared between the FC and UC groups. Cox's proportional hazard model was used to identify risk factors for RBO with the 2nd SEMS.

RESULTS

There was a significant difference between the FC and UC groups only in the 2nd SEMS diameter. Median OS and TRBO were 195 and 238 days in FC patients and 306 and 455 days in UC patients, respectively, with no significant differences between the two groups. No significant differences were observed in the stent-related adverse event rate. In multivariate analyses, only the 2nd SEMS diameter was significant (P = 0.009). Median TRBO were 455, 238, and 103 days in 10-mm UC, 10-mm FC, and 8-mm UC patients, with 10-mm UC patients having significantly longer TRBO than 10-mm FC and 8-mm UC patients (P = 0.020 and 0.001).

CONCLUSION

SEMS exchange to 10-mm UC may be appropriate for RBO of PC with FC as the 1st SEMS.

Stent Selection in Preoperative Biliary Drainage for Patients With Operable Pancreatic Cancer Receiving Neoadjuvant Therapy: A Meta-Analysis and Systematic Review

With the increasing use of neoadjuvant therapy (NAT) in patients with pancreatic cancer to reduce tumor burden on prognosis, preoperative biliary drainage (PBD) is becoming increasingly necessary. The aim of this study was to summarize the latest evidence and compare the clinical efficacy of metal stents (MS) and plastic stents (PS) in patients undergoing neoadjuvant therapy for operable pancreatic cancer. Eligible studies were searched in PubMed, Embase and Cochrane Library from their inception to September 2021. In this study, RevMan 5.4 was used to perform the analyses. Two randomized controlled trials (RCTs) and six retrospective studies with 316 patients were included. All patients had pancreatic cancer and received NAT before surgical resection. Meta-analysis showed that the rate of endoscopic reintervention in MS (26/143, 18%) group was lower than that of PS (122/153, 80%) group (P < 0.05). The rate of stent-related complications in MS group was lower (18/118, 15%) than that of PS (52/117, 44%) group (P = 0.02). But there were no significant differences in operative time, operative blood loss, overall postoperative complications, postoperative hospitalization days and total medical costs between the two groups. For operable pancreatic cancer patients undergoing NAT surgery, MS was preferred over PS in terms of the incidence of endoscopic reintervention and stent-related complications. More clinical trials are needed in the future to confirm these data with higher levels of evidence.

Safety and Efficacy of a Large-Bore Biliary Metallic Stent for Malignant Biliary Obstruction

Self-expandable metallic stents (SEMSs) are typically inserted in patients with unresectable malignant biliary obstruction. However, SEMSs are susceptible to occlusion. To overcome this issue, we developed a large-bore, dumbbell-shaped, fully covered SEMS (FCSEMS-L) and compared its efficacy and safety with those of a conventional FCSEMS (FCSEMS-C) in patients with malignant biliary obstruction. Methods: Patients with unresectable distal malignant biliary obstruction were retrospectively enrolled between January 2011 and February 2021. All patients underwent endoscopic insertion of FCSEMSs. Recurrent biliary obstruction (RBO), patient survival time, complications, and prognosis were analyzed. Results: RBO occurred in 31 patients (35.6%) who received an FCSEMS-L, and in 34 (45.9%) who received an FCSEMS-C. Stent occlusion occurred in 19 patients (21.8%) who received an FCSEMS-L, and in 22 (29.7%) who received an FCSEMS-C. Stent migration occurred in 12 patients (13.8%) with an FCSEMS-L and 12 (16.2%) with an FCSEMS-C. The median time to RBO (TRBO) was 301 days with an FCSEMS-L and 203 days with an FCSEMS-C. The median survival time was 479 days with an FCSEMS-L and 523 days with an FCSEMS-C. The TRBO and patient survival time did not significantly differ between the two groups. Conclusions: There were no significant differences in efficacy and complication rates between the fully covered large bore SEMSs and conventional fully covered SEMSs.

Angle of covered self-expandable metallic stents after placement is a risk factor for recurrent biliary obstruction

BACKGROUND

Studies have shown that covered self-expandable metallic stents (CSEMS) with a low axial forces after placement can cause early recurrent biliary obstruction (RBO) due to precipitating sludge formation.

AIM

To ascertain whether the angle of CSEMS after placement is a risk factor for RBO in unresectable distal malignant biliary obstruction (MBO).

METHODS

Between January 2010 and March 2019, 261 consecutive patients underwent self-expandable metallic stent insertion by endoscopic retrograde cholangiopancreatography at our facility, and 87 patients were included in this study. We evaluated the risk factors for RBO, including the angle of CSEMS after placement as the primary outcome. We measured the obtuse angle of CSEMS after placement on an abdominal radiograph using the SYNAPSE PACS system. We also evaluated technical and functional success, adverse events, time to RBO (TRBO), non-RBO rate, survival time, cause of RBO, and reintervention procedure as secondary outcomes.

RESULTS

We divided the patients into two cohorts based on the presence or absence of RBO. The angle of CSEMS after placement (per 1° and per 10°) was evaluated using the multivariate Cox proportional hazard analysis, which was an independent risk factor for RBO in unresectable distal MBO [hazard ratio, 0.97 and 0.71; 95% confidence interval (CI): 0.94-0.99 and 0.54-0.92; P = 0.01 and 0.01, respectively]. For early diagnosis of RBO, the cut-off value of the angle of CSEMS after placement using the receiver operating characteristic curve was 130° [sensitivity, 50.0%; specificity 85.5%; area under the curve 0.70 (95%CI: 0.57-0.84)]. TRBO in the < 130° angle group was significantly shorter than that in the ≥ 130° angle group (P < 0.01).

CONCLUSION

This study suggests that the angle of the CSEMS after placement for unresectable distal MBO is a risk factor for RBO. These novel results provide pertinent information for future stent management.

Biliary metal stents should be placed near the hilar duct in distal malignant biliary stricture patients

BACKGROUND

Endoscopic biliary drainage using a self-expandable metallic stent (SEMS) has been widely performed to treat distal malignant biliary obstruction (DMBO). However, the optimal position of the stent remains unclear.

AIM

To determine the ideal position for SEMS placement.

METHODS

In total, 135 DMBO patients underwent SEMS (uncovered or covered) placement over a ten-year period. A total of 127 patients with biliary obstruction between the junction of the cystic duct and Vater's papilla were enrolled. An SEMS was placed through the upper common bile duct 2 cm from the biliary hilar duct in 83 patients (Hilar group) or near the top of the biliary obstruction in 44 patients (Lower group). Technical and functional success, adverse events, and risk factors for SEMS dysfunction were evaluated.

RESULTS

The stent patency period was significantly longer in the Hilar group than in the Lower group (P value < 0.01). In multivariate analysis, the only statistically significant risk factor for SEMS dysfunction was being in the Lower group (hazard ratio: 9.94, 95% confidence interval: 2.25-44.0, P < 0.01).

CONCLUSION

A longer patency period was achieved by positioning the SEMS near the biliary hilar duct.

Laser-cut-type versus braided-type covered self-expandable metallic stents for distal biliary obstruction caused by pancreatic carcinoma: a retrospective comparative cohort study

BACKGROUND/AIMS

Covered self-expandable metallic stents (CMSs) are widely used for malignant distal biliary obstructions (MDBOs) caused by pancreatic carcinoma. This study compared the efficacy and safety of the laser-cut-type and braided-type CMSs.

METHODS

To palliate MDBOs caused by pancreatic carcinoma, the laser-cut-type CMSs was used from April 2014 to March 2017, and the braided-type CMSs was used from April 2017 to March 2019. The tested self-expandable metallic stents were equipped with different anti-migration systems.

RESULTS

In total, 47 patients received CMSs for MDBOs (24 laser-cut type, 23 braided-type). The time to recurrent biliary obstruction (TRBO) was significantly longer in the braided-type CMSs (p=0.0008), and the median time to stent dysfunction or patient death was 141 and 265 days in the laser-cut-type CMSs and braided-type CMSs, respectively (p=0.0023). Stent migration was the major cause of stent dysfunction in both groups, which occurred in 37.5% of the laser-cut-type CMSs and 13.0% of the braidedtype CMSs. There were no differences in the survival duration between the groups.

CONCLUSION

The TRBO was significantly longer for the braided-type CMSs with an anti-migration system than for the laser-cuttype. Stent migration tended to be less frequent with the braided-type CMSs than with the laser-cut-type CMSs.

Stent placement above the sphincter of Oddi is a useful option for patients with inoperable malignant hilar biliary obstruction

BACKGROUND AND AIMS

Endoscopic biliary drainage (EBD) is essential for the management of malignant hilar biliary obstruction (MHBO). We prospectively evaluated the efficacy and safety of "inside-stent" therapy, where a plastic stent is placed above the sphincter of Oddi without endoscopic sphincterotomy, in patients with inoperable MHBO.

METHODS

This study was a multicenter, single-blinded, randomized controlled trial at three centers. Patients with inoperable MHBO were enrolled in this study, and randomly assigned to receive an inside-stent or conventional-stent therapy. The primary endpoint was cumulative stent patency of the initial stent. The secondary endpoints were second stent patency, technical and clinical success rate, adverse events, re-intervention rate, and overall patient survival.

RESULTS

Forty-three patients were randomly assigned to the inside-stent group (n = 21) or the conventional-stent group (n = 22). The median cumulative stent patency of the initial stent was 123 days in the inside-stent group and 51 days in the conventional-stent group (P = .031). For patients with the initial stent dysfunction in the conventional-stent group, the inside-stent was placed as a second stent, and its patency was significantly longer than that of the initial stent (P = .0001). The technical and clinical success rate, re-intervention rate, second stent patency, adverse events, and survival probability did not differ between the groups.

CONCLUSIONS

Inside-stent therapy appears to be useful not only as an initial stent but also as a second stent for patients with inoperable MHBO.

TRIAL REGISTRATION NUMBER

UMIN000004587.

Covered self-expandable metallic stent versus plastic stent for preoperative endoscopic biliary drainage in patients with pancreatic cancer: a multi-center retrospective cohort study

BACKGROUND

Expanding indications for neoadjuvant chemotherapy (NAC) for resectable pancreatic cancer prolong the period from diagnosis to surgery. In resectable pancreatic cancer with malignant biliary obstruction (MBO), the biliary drainage method without any biliary events is ideally required to safely perform NAC as planned. Plastic stents (PS) have been traditionally used for preoperative biliary drainage; however, recently, covered self-expandable metallic stents (CSEMS) have emerged as a tool for preoperative biliary drainage.

AIMS

To compare CSEMS with PS for preoperative biliary drainage in the management of resectable pancreatic cancer with MBO.

METHODS

In this multicenter retrospective cohort study, we compared CSEMS with PS for preoperative biliary drainage in patients with pancreatic cancer at three tertiary care centers between 2008 and 2019.

RESULTS

Of the 120 enrolled patients, 45 underwent CSEMS and 75 underwent PS. No significant difference was observed in the basic characteristics between the groups. The rate of recurrent biliary obstruction (RBO) was significantly lower and the time to RBO was significantly longer in the CSEMS group. In multivariate analysis, CSEMS was an independent factor for a longer RBO. However, pancreatitis and cholecystitis were more common in the CSEMS group. The surgery-related adverse events were not significantly different between the two groups, except for longer surgery time and time to discharge in the CSEMS group.

CONCLUSIONS

CSEMS for preoperative endoscopic biliary drainage in patients with pancreatic cancer reduced RBO, although the risk for pancreatitis or cholecystitis could be increased.

Preoperative biliary drainage for pancreatic cancer

Pancreatic adenocarcinoma is currently one of the leading causes of cancer-related morbidity and mortality with dismal long term survival after diagnosis. Nearly 85% of pancreatic cancer patients present with advanced disease precluding curative surgical resection. In those who are candidates for surgery, preoperative biliary drainage (PBD) has been developed since the 1960s in order to improve surgical outcomes. While obstructive jaundice in resectable pancreatic cancer has been traditionally treated before surgical resection in all patients, data over the past decade demonstrated increased perioperative complications and morbidity with systematic PBD compared to direct surgery. With new evidence of potential adverse events, the role of routine PBD is being reassessed. Current indications for PBD include cholangitis, delayed surgery, and relief of jaundice in patients planned to receive neoadjuvant therapy (NAT). NAT is being increasingly utilized in borderline resectable as well as resectable pancreatic cancer and a higher proportion of patients with likely require PBD in the future. The evidence for endoscopic retrograde cholangiopancreatography as first line for PBD is robust with supporting data from endoscopic ultrasound assisted biliary drainage. Self-expanding metal stent was shown to be cost-effective in recent studies without increase in morbidity compared to plastic stents in this setting. In this review, we will summarize the current evidence for PBD in patients with pancreatic cancer.

Superiority of Self-Expandable Metallic Stents Over Plastic Stents in Treatment of Malignant Distal Biliary Strictures

BACKGROUND & AIMS

Treatment of malignant biliary strictures with endoscopic retrograde cholangiopancreatography (ERCP) guided stent placement is highly effective. Our objective was to compare the efficacy and adverse outcomes between plastic stents (PS) and self-expandable metallic stents (SEMS).

METHODS

A cohort study was performed of all consecutive patients who underwent ERCP with stent placement for the management of malignant biliary stricture. Comparisons on clinical success, patency duration, stent dysfunction, unplanned reintervention and adverse outcomes were performed. Univariate and multivariable analyses were performed to identify factors associated with clinical success, need for reintervention, and stent dysfunction.

RESULTS

From 2012 to 2019, 1139 patients underwent ERCP with PS placement while 1008 patients received SEMS for the management of malignant biliary stricture. In distal strictures, SEMS reported a significantly higher rate of clinical success compared with PS (94.1% vs 87.4%, P < 0.001) and a lower rate of unplanned reintervention (17.1% vs 27.4%, P < 0.001). In hilar strictures, the rates of clinical success and unplanned intervention were comparable. The patency duration and time to unplanned reintervention were significantly longer with SEMS than PS, irrespective of stricture location. In distal stricture, PS was associated with a significantly higher rate of cholangitis than SEMS (6.9% vs 2.4%; P < .001) but a lower rate of pancreatitis (3.6% vs 6%; P = 0.021).

CONCLUSION

Given superior efficacy, durability and lower rates of cholangitis, SEMS should be offered as the first line endoscopic treatment option for malignant distal biliary stricture. For malignant hilar stricture, SEMS is an attractive alternative to PS in some cases by offering a comparable efficacy with a superior durability.

Prevention of pancreatitis after stent implantation for distal malignant biliary strictures: systematic review and meta-analysis

INTRODUCTION

Biliary stent placement remains a palliative treatment for patients with unresectable distal malignant biliary strictures (DMBS). The incidence of post-ERCP-pancreatitis (PEP) significantly increases in patients receiving fully covered self-expandable metal stents (FCSEMS) who undergo endoscopic retrograde cholangiopancreatography (ERCP).

AREAS COVERED

This review provides an overview of prevention of PEP after stent implantation for DMBSs. The following operational variables were evaluated: (1) stent type (plastic or metal stent); (2) stent location (above or across the sphincter of Oddi); (3) prophylactic pancreatic duct stent placement; (4) endoscopic sphincterotomy (EST). PubMed, EMBASE, and Cochrane database were searched to identify eligible studies up to October 2021. The odds ratio (OR) with 95% confidence intervals (CI) were pooled using fixed- or random- effects models.

EXPERT OPINION

1. PEP occurs more frequently in DMBS patients with self-expandable metal stents (SEMS) compared to that plastic stent (PS). 2. The PEP incidence is higher in covered stents than that in uncovered self-expandable metal stents (USEMS), but not significantly. 3. PEP incidence increases in patients receiving transpapillary FCSEMS placement, particularly when there is an absence of pancreatic duct dilation, and prophylactic pancreatic stenting is recommended for these patients. 4. Limited studies with small sample indicate that there is no significant difference in PEP incidence between transpapillary and suprapapillary stents placement for DMBS. 5. Limited studies indicate that EST does not significantly affect the incidence of pancreatitis in DMBS patients.

Plastic or self-expandable metal stent: Which is the most suitable for patients with pancreatic head cancer in the upcoming era of neoadjuvant chemotherapy? A review

Obstructive jaundice is a major symptom of pancreatic head cancer, and although its amelioration is required before scheduling chemotherapy, the decision to perform biliary drainage for resectable pancreatic cancer has remained controversial. In recent years, the effectiveness of neoadjuvant therapy for pancreatic cancer has been reported. Preoperative biliary drainage has become increasingly necessary, making the choice of stent an important one; thus, the longer the waiting period extends through neoadjuvant chemotherapy, the more durable stents - such as self-expandable metallic stents, rather than plastic stents - would be desired as an option. Still, there is insufficient evidence regarding surgical outcomes and long-term prognosis, and further confirmatory studies are needed. Through this review, we aim to provide an update on the characteristics of biliary stents and preoperative biliary drainage for potentially resectable pancreatic cancer.

Modified non-flared fully covered self-expandable metal stent for preoperative biliary drainage in pancreatic cancer

BACKGROUND AND AIM

Durable biliary drainage is essential in patients with pancreatic cancer in the era of effective neoadjuvant chemotherapy (NACT). Plastic stent (PS) tends to occlude easily, and current metal stents are designed for nonresectable cancer. We evaluated the efficacy of a modified non-flared fully covered self-expandable metal stent (M-FCSEMS) during the perioperative period in patients with resectable or borderline resectable pancreatic cancer.

METHODS

Consecutive patients with resectable or borderline resectable pancreatic ductal adenocarcinoma had a 12-mm M-FCSEMS (M-FCSEMS group) or 7-Fr PS (PS group) placed for biliary decompression before NACT or curative-intent surgery. The primary outcome was the re-intervention rate, and secondary outcomes were technical success, stent patency, and adverse events (AEs).

RESULTS

Endoscopic stent placement was technically successful in all 60 patients. Twenty-three patients underwent surgery and 37 NACT before surgery. Re-intervention was performed in 10.0% (3/30) of patients in the M-FCSEMS group and 36.7% (11/30) of patients in the PS group (P = 0.030). The stent patency at 180 days was 89.8% (95% confidence interval, 77.3-100.0%) in the M-FCSEMS group and 30.2% (95% confidence interval, 11.4-80.0%) in the PS group (P < 0.0001). Stent-related AEs occurred in 10.0% (3/30) in the M-FCSEMS group and 40.0% (12/30) in the PS group (P = 0.015). Surgery-related AEs occurred in 10.5% (2/19) and 14.3% (3/21) in the M-FCSEMS and PS groups (P = 0.549).

CONCLUSIONS

Modified non-flared fully covered self-expandable metal stents are effective and safe for durable biliary drainage in patients with resectable or borderline resectable pancreatic cancer during the perioperative period.

Fully covered metal biliary stents: A review of the literature

Fully covered self-expandable metal stents (FCSEMS) represent the latest advancement of metal biliary stents used to endoscopically treat a variety of obstructive biliary pathology. A large stent diameter and synthetic covering over the tubular mesh prolong stent patency and reduce risk for tissue hyperplasia and tumor ingrowth. Additionally, FCSEMS can be easily removed. All these features address issues faced by plastic and uncovered metal stents. The purpose of this paper is to comprehensively review the application of FCSEMS in benign and malignant biliary strictures, biliary leak, and post-sphincterotomy bleeding.

Current Status of Endoscopic Biliary Drainage in Patients with Distal Malignant Biliary Obstruction

Distal malignant biliary obstruction is caused by various malignant diseases that require biliary drainage. In patients with operable situations, preoperative biliary drainage is required to control jaundice and cholangitis until surgery. In view of tract seeding, endoscopic biliary drainage is the first choice. Since neoadjuvant therapies are being developed, the time to surgery is increasing, especially in pancreatic cancer cases. Therefore, it requires long stent patency. Recently, preoperative biliary drainage using self-expandable metal stents has been reported as a useful modality to secure long stent patency. In patients with unresectable distal malignant biliary obstruction, self-expandable metal stent is the first choice for maintaining long stent patency. Although there are many comparison studies between a covered and an uncovered self-expandable metal stent, their use is still controversial. Recently, endoscopic ultrasound-guided biliary drainage has been performed as an alternative treatment. The clinical success and stent patency are favorable. We should take into consideration that both endoscopic retrograde cholangiopancreatography-guided biliary drainage and endoscopic ultrasound-guided biliary drainage have advantages and disadvantages and chose the drainage method depending on the patient’s situation or the expertise of the endoscopist. Here, we discuss the current status of endoscopic biliary drainage in patients with distal malignant biliary obstruction.

Uncovered versus covered metallic stents for the management of unresectable malignant distal biliary obstruction: a randomized multicenter trial

OBJECTIVE

The treatment result of the uncovered metallic stent (uncovered MS) and covered metallic stent (covered MS) for unresectable malignant distal biliary obstruction is controversial. This time, we conducted this study to compare the efficacies and complication rates of uncovered MS and covered MS in unresectable malignant distal biliary obstructions at a prospective randomized multicenter trial.

MATERIALS AND METHODS

From April 2014 to September 2018, patients with unresectable malignant distal biliary obstruction were randomly assigned to 2 groups: the uncovered MS group and the covered MS group.

RESULTS

92 treatment results patients were discussed. 48 patients were assigned to the uncovered MS group and 44 cases were assigned to the covered MS group. Both groups showed a drainage effect. No significant difference was found in the drainage effect between the 2 groups. The number of stent occlusion was significantly greater (p = .0467) in uncovered MS (43.8%) comparing with those in covered MS (22.7%). As the cause of stent occlusion, tumor ingrowth was significantly greater (p < .001) in the uncovered MS group (35.4%) than in the covered MS group (2.3%). The median stent patency period was significantly longer (p = .0112) in the covered MS group (455 days) than that of the uncovered MS group (301 days). A significant difference in the median survival period was not found between the 2 groups.

CONCLUSIONS

Covered MS showed the possibility of extending the stent patency period by suppressing tumor ingrowth more than uncovered MS does. The UMIN Clinical Trial Registry number is UMIN000015093.

Advances in the management of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a primary malignancy of the bile ducts with three anatomically and molecularly distinct entities: Intrahepatic CCA (iCCA), perihilar CCA (pCCA), and distal CCA. As a result of phenotypic and anatomic differences they differ significantly with respect to management. For each type of CCA there have been significant changes in management over the last several years which will be discussed in this review. Although resection remains the standard of care for all types of CCA, liver transplantation has been established as curative treatment for selected patients with pCCA and is being evaluated for iCCA with early success. With respect to systemic therapy capecitabine is now first line adjuvant therapy for all biliary tract malignancies after curative intent resection. Progress in exploiting the pathologic mutations and molecular abnormalities has also yielded regulatory approval of targeted therapy for CCA in patients with acquired alterations in the fibroblast growth factor receptor. There is also increased consensus in managing malignant biliary obstruction associated with CCA where pre-operative biliary stenting is not beneficial while self-expanding metal stents have been shown to be superior to plastic stents in patients who are not surgical candidates.

Advanced Endoscopic Techniques for the Diagnosis of Pancreatic Cancer and Management of Biliary and GastricOutlet Obstruction

Following high-quality imaging studies for staging, endoscopic ultrasound examination fine needle aspiration/biopsy is the preferred modality for tissue diagnosis of pancreatic cancer. Endoscopic retrograde cholangiopancreatography with metal stent placement is used for palliation of malignant biliary obstruction. Metal stents can be placed in patients with resectable pancreatic cancer in whom surgery is going to be delayed. For palliation of gastric outlet obstruction, endoscopic enteral stenting is often selected because of its less invasiveness. Endoscopic ultrasound-guided biliary drainage for malignant biliary obstruction or gastrojejunostomy for gastric outlet obstruction are emerging less invasive techniques as compared with palliative surgery.

Development of biliary stent applying the antibacterial activity of silver: A literature review

BACKGROUND

Endoscopic transpapillary stenting is commonly performed in patients with obstructive jaundice caused by a biliary stricture. Although the plastic stent (PS) is widely used for biliary drainage because of the low-cost and easy procedure, patency is short after placement in the bile duct because of the small diameter. Dysfunction of PS is primarily caused by biliary sludge that forms as a result of bacterial adhesion and subsequent biofilm formation on the inner surface of the stent. It is well known that silver ions have excellent antibacterial activity against a wide range of microorganisms.

OBJECTIVE

This review provides an overview and perspective of the significance of silver-coated biliary stents.

METHODS

We collected literature regarding silver-coated biliary stents, reviewed the current research/development status and discussed their possible usefulness.

RESULTS

To date, several in vivo/vitro studies evaluated the patency of silver-blended or silver-coated biliary stents. These studies suggested that the silver coating on a PS was likely to prolong the patency period.

CONCLUSION

The development of biliary stents using silver is expected to prolong stent patency and prevent frequent stent replacement.

[A Recent Update on Endoscopic Drainage of Advanced Malignant Hilar Obstruction]

Malignant hilar obstruction (MHO) is considered an aggressive perihilar obstruction caused by cholangiocarcinoma, gallbladder cancer, or metastatic malignancies and has a poor prognosis. Although surgical resection is the only curative treatment method, the majority of patients with MHO do not undergo surgery due to an advanced inoperable state at presentation. Currently, effective biliary drainage provides the necessary palliation for symptomatic improvement. Among the drainage methods, percutaneous access may be preferred, especially for advanced MHO because of the technical difficulty involved with other techniques. Recently, primary endoscopic palliation using plastic or metal stents has been shown to have higher technical feasibility and clinical success without increasing adverse events even in patients with high-degree MHO. The development of various accessories, endoscopic ultrasonography, and advances in techniques have facilitated primary endoscopic intervention. However, some aspects continue to be debated such as the palliation methods, appropriate stents, the number of stents, the deployment methods, and additional local ablation therapies. Therefore, this review discusses the current optimal endoscopic treatment methods for advanced MHO based on reported literature.