Retrospective comparative study of new slim-delivery and conventional large-cell stents for stent-in-stent methods for hilar malignant biliary obstruction

OBJECTIVES

Endoscopic management of unresectable hilar malignant biliary obstruction (HMBO) is technically challenging, and effectiveness of stent-in-stent using large-cell, metal stents was reported. A new, large-cell stent with a 6F tapered delivery system was recently developed. The aim of this study was to compare clinical outcomes of slim-delivery and conventional large-cell stents.

METHODS

This was a multicenter retrospective comparative study of stent-in-stent methods using slim-delivery stents (Niti-S Large Cell SR Slim Delivery [LC slim-delivery]) and conventional stents (Niti-S large-cell D-type; LCD) for unresectable HMBO.

RESULTS

Eighty-three patients with HMBO were included; 31 LC slim-delivery and 52 LCD. Overall technical and clinical success rates were 100% and 90% in LC slim-delivery group and 98% and 88% in LCD group. Use of the LC slim-delivery was associated with shorter stent placement time in the multiple regression analysis, with a stent placement time of 18 and 23 min in LC slim-delivery and LCD groups, respectively. The early adverse event (AE) rate of LC slim-delivery was 10%, with no cholangitis or cholecystitis as compared to 23% in the LCD group. Recurrent biliary obstruction (RBO) rates and time to RBO were comparable between the two groups: 35% and 44%, and 8.5 and 8.0 months in LC slim-delivery and LCD groups, respectively. The major cause of RBO was tumor ingrowth (82%) in the LC slim-delivery group and sludge (43%) and ingrowth (48%) in LCD group.

CONCLUSION

Stent-in-stent methods using LC slim-delivery shortened stent placement time with low early AE rates and comparable time to RBO in patients with HMBO.

Study protocol for a prospective, multicentre, phase II trial on endoscopic treatment using two fully covered self-expandable metallic stents for benign strictures after hepaticojejunostomy

INTRODUCTION

The current endoscopic treatment for postoperative benign hepaticojejunostomy anastomotic stricture (HJAS) has a high technical success rate and is highly effective in the short term. However, long-term results have shown a high rate of stenosis recurrence, which indicates an insufficient response to treatment. Three prospective studies on fully covered self-expandable metallic stent (FC-SEMS) treatment for benign HJAS used the stenosis resolution rate as the primary endpoint, and no study has yet used the long-term non-stenosis rate (at 12 months) as the primary endpoint.

METHODS AND ANALYSIS

We launched the 'saddle-cross study', which will be conducted as a multicentre, prospective intervention of endoscopic treatment using two modified FC-SEMSs (BONASTENT️ M-Intraductal) that have been improved for benign stenosis in patients with benign HJAS, with the long-term non-restenosis rate (at 12 months) as the primary endpoint. This study aims to evaluate the long-term non-restenosis rate (at 12 months) and safety of the saddle-cross technique for benign HJAS. We plan to enrol 50 participants.

ETHICS AND DISSEMINATION

This study has been approved by the Certified Review Board of the National Cancer Center, Japan (CRB3180009). The results will be reported at various conferences and published in international peer-reviewed journals.

Removal of Duckbill-type laser-cut anti-reflux metal stents: Clinical evaluation and in vitro study

Objectives

Duckbill-type metal stent (DMS) was the first laser-cut biliary metal stent with an anti-reflux valve. Removal of DMS is believed to be difficult and relevant reports are scarce. This study aims to investigate the feasibility of DMS removal.

Methods

We retrospectively analyzed patients who underwent DMS removal between June 2019 and March 2022 to evaluate success rates and factors affecting outcomes. In addition, six different methods of DMS removal were reproduced in vitro, varying removal devices, angle of applied force, and grasped location. Extraction resistance, the distance of forceps stroke, and stent length after removal were compared.

Results

Forty patients were enrolled, and DMS removal was successful in 31 cases (78%). No adverse events were observed. Tumor ingrowth was evident in 78% (7/9) of failed cases. Patients receiving biliary metal stents for the first time (naïve cases), long indwelling time, longer stent, and stent tearing during removal were associated with unsuccessful stent removal. In the in vitro study, a larger force was required to remove the stent at an extraction angle of 120° than at 0°. Among cases in which force was applied at 120°, the load tended to be lower when rat-tooth forceps were applied horizontally across the stent.

Conclusions

Stent removal was possible in a majority of cases. Deployment of additional stents inside DMS may be preferable to forceful removal in the presence of factors associated with difficult stent removals, such as tumor ingrowth, naïve cases, longer stents, long indwelling time, and stent tearing during removal.

A novel endoscopic technique using fully covered self-expandable metallic stents for benign strictures after hepaticojejunostomy: the saddle-cross technique (with video)

BACKGROUND

In recent years, the number of patients with hepaticojejunostomy anastomotic strictures has increased. Balloon dilation and placement of multiple plastic stents have proven effective for hepaticojejunostomy anastomotic strictures. However, for refractory strictures, there is often a need for repeated endoscopic procedures within a short period. This study aimed to assess the efficacy and safety of the new saddle-cross technique, which uses two fully covered self-expandable metallic stents.

METHODS

This was a retrospective analysis of 20 patients with benign hepaticojejunostomy anastomotic strictures who underwent placement of two fully covered self-expandable metallic stents at the National Cancer Center, Japan, from November 2017 to June 2021.

RESULTS

The technical and clinical success rates were 100% (20/20). The median time of the procedure was 61 (range 25-122) min. The scheduled stent removal rate was 70% (14/20). Spontaneous dislodgement of the stent was observed on computed tomography in five patients (25.0%). The non-restenosis rate 12 months after the saddle-cross technique was 88.2% (15/17). Procedure-related early adverse events included mild ascending cholangitis in three patients (15.0%) and sepsis in one patient (5.0%). Procedure-related late adverse events included mild ascending cholangitis in three patients (15.0%) and bile duct hyperplasia in one patient (5.0%).

CONCLUSIONS

The saddle-cross technique performed using two fully covered self-expandable metallic stents resulted in promising long-term stricture resolution with a high technical success rate. Based on these findings, the saddle-cross method can be considered an option for the standard procedure for benign hepaticojejunostomy anastomotic strictures.

Biliary stones or ulcers at the choledochojejunal anastomotic site involving the jejunal mucosa at stent removal may be recurrent factors in patients with benign choledochojejunal anastomotic stenosis undergoing endoscopic biliary stenting using fully-covered self-expandable metal stents

BACKGROUND

Temporary fully-covered self-expandable metal stent (FCSEMS) placement is performed for benign choledochojejunal anastomotic stenosis (bCJS). However, recurrence may develop after stricture resolution. We investigated endoscopic biliary stenting using FCSEMS for bCJS.

METHODS

Sixteen bCJS patients with FCSEMS placement were retrospectively analyzed. FCSEMS was removed endoscopically after 2 months. Technical success, stricture resolution, recurrence, and adverse events were evaluated.

RESULTS

The technical success rate for FCSEMS placement was 94% (15/16). Biliary stones were detected and extracted in 4 patients. FCSEMS removal was successfully performed on 14 patients, excluding 1 with stent migration. At FCSEMS removal, stricture resolution was noted in 14 patients; however, 4 had anastomotic ulcers. The median follow-up was 319 days. Three patients with a history of repeated plastic stent placement had no recurrence. Four out of 15 patients (27%) had recurrence, and three had no recurrence after additional interventions. Biliary stones before first FCSEMS placement (p=0.003) or anastomotic ulcers at FCSEMS removal (p=0.018) were associated with recurrence.

CONCLUSIONS

Although FCSEMS placement was useful for stricture resolution, recurrence was detected in patients with biliary stones before first FCSEMS placement or anastomotic ulcers at FCSEMS removal. Anastomotic ulcers are a risk factor for recurrence and only detected by endoscopy.

Multicenter study of lumen-apposing metal stents with or without pigtail in endoscopic ultrasound-guided biliary drainage for malignant obstruction-BAMPI TRIAL: an open-label, randomized controlled trial protocol

Background

It is unclear whether the insertion of an axis-orienting double-pigtail plastic stent (DPS) through biliary lumen-apposing meal stent (LAMS) in EUS-guided choledochoduodenostomy (CDS) improves the stent patency. The aim of this study is to determine whether this technical variant offers a clinical benefit in EUS-guided biliary drainage (BD) for the management of distal malignant biliary obstruction.

Methods/design

This is a multicenter open-label, randomized controlled trial with two parallel groups. Eighty-four patients with malignant biliary obstruction will undergo EUS-BD (CDS type) using LAMS in 7 tertiary hospitals in Spain and will be randomized to the LAMS and LAMS plus DPS groups. The primary endpoint is the rate of recurrent biliary obstruction, as a stent dysfunction parameter, detected during follow-up. Secondary endpoints: technical and clinical success (reduction in bilirubin > 50% within 14 days of stent placement), safety, and others (number of reinterventions, time to biliary obstruction, prognostic factors, survival rate).

Discussion

The BAMPI trial has been designed to determine whether the addition of a coaxial axis-orienting DPS through LAMS is superior to LAMS alone to prevent stent dysfunction.

Trial registration

ClinicalTrials.govNCT04595058. Registered on October 14, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06106-1.

A novel laser-cut fully covered metal stent with anti-reflux valve in patients with malignant distal biliary obstruction refractory to conventional covered metal stent

BACKGROUND

Stenting against recurrent biliary obstruction (RBO) after placement of covered metal stent (CMS) for distal malignant biliary obstruction (MBO) is still challenging. This study investigated the feasibility of a novel laser-cut fully CMS with anti-reflux valve in patients with distal MBO refractory to conventional CMS.

METHODS

Patients who underwent Duckbill-type metal stent (DMS) placement between June 2019 and May 2020 were included. Early complications, causes of RBO including non-occlusion cholangitis, and time to RBO (TRBO) were evaluated. TRBO of DMS was also compared with that of previous CMS.

RESULTS

Thirty patients were included: pancreatic cancer/metastatic lymph nodes in 29 patients/one patient; duodenal stenosis in 13 patients. Technical and functional success were achieved in all patients. Mild cholangitis and mild pancreatitis developed in each one. Median follow-up period was 167 days (range, 23-527 days). RBO occurred in nine patients (30%): sludge formation in four patients, hemobilia in one patient, symptomatic distal stent migration in three patients, and non-occlusion cholangitis in one patient. TRBO of DMS was significantly longer than that of previous CMS (median 224 days vs median 120 days, P = .0025). DMS was successfully removed in all of six patients when re-intervention was needed.

CONCLUSIONS

Duckbill-type metal stent might be safe and effective in patients with distal MBO refractory to conventional CMS.

Is a coaxial plastic stent within a lumen-apposing metal stent useful for the management of distal malignant biliary obstruction?

BACKGROUND

There are uncertainties concerning the possible benefits derived from the insertion of double-pigtail plastic stents (DPS) within lumen-apposing metal stents (LAMS) in EUS-guided choledochoduodenostomy (CDS). The aim of this study was to determine whether a DPS within a biliary LAMS offers a potential benefit in EUS-guided CDS for the palliative management of malignant biliary obstruction.

METHODS

This was a multicentre retrospective study at three tertiary institutions.

PERIOD

May 2015 to August 2020. Two interventional strategies (LAMS alone and LAMS plus DPS) were compared. The choice was the endoscopist's discretion. Inclusion: unresectable/inoperable biliopancreatic tumours with previous failed ERCP. Clinical success: bilirubin decrease > 30% at 4 weeks.

RESULTS

Forty-one consecutive cases of EUS-CDS using biliary LAMS were treated (22 women; mean age, 72.3 years) during the study period. The procedure was technically successful in 39 (95.1%), who were managed using the two strategies (22 LAMS alone; 17 LAMS plus DPS). No differences between the groups, in terms of clinical success (77.3 vs 87.5%, p = 0.67), adverse events (AEs, 13.6 vs 11.8%, p = 0.99), recurrent biliary obstruction (RBO, 13.6 vs 23.5%, p = 0.67), or survival rate (p = 0.67) were encountered. The LAMS alone group had a shorter length of procedure (50 min vs 66 min, p = 0.102). No risk factors related to clinical success, AEs, RBO, or survival were detected.

CONCLUSIONS

The technical variant of adding a coaxial DPS within LAMS in EUS-CDS seems not to be enough to prevent biliary morbidities, and it is a time-consuming strategy. Although prospective studies are needed, these results do not support its routine use.

Endoscopic treatment of hepaticojejunostomy anastomotic strictures using fully-covered metal stents

OBJECTIVES

With the emergence of the double-balloon endoscope (DBE), hepaticojejunostomy anastomotic strictures (HJASs) are increasingly managed endoscopically. However, balloon dilation and/or plastic stent placement may be associated with low stricture resolution rates and long treatment duration. We utilized a fully-covered metal stent (FCSEMS), which was designed for temporary placement for benign biliary strictures, and assessed its feasibility for patients with HJASs.

METHODS

We retrospectively studied 20 patients who underwent DBE-assisted FCSEMS placement for HJASs between June 2017 and March 2019. The FCSEMS was removed endoscopically at three months of stent placement. The outcomes investigated were the stricture resolution at the time of FCSEMS removal, the stricture recurrence, and adverse events.

RESULTS

Among 20 patients treated, stricture resolution was achieved in 17 patients (85.0%) at three months of stent placement. The FCSEMS was removed endoscopically without any technical difficulties in all cases except for two with asymptomatic stent migration due to stricture resolution. During a median follow-up period of 11.9 months (interquartile range, 7.5-18.0 months), an HJAS recurred in one patient (5.9%). For two patients without stricture resolution and one patient with recurrent stricture, another FCSEMS placement for 77, 84, and 186 days resolved the stricture. The overall stricture resolution rate was 95.0%. In one patient with FCSEMS-induced de novo stricture, long-term plastic stent placement was required. Procedure-related adverse events included mild cholangitis in two patients and mild pancreatitis in one patient.

CONCLUSIONS

Endoscopic treatment using a FCSEMS via DB-ERCP was a feasible and effective treatment option for a HJAS.

Antireflux metal stent for biliary obstruction: Any benefits?

Endoscopic retrograde cholangiopancreatography with stent placement has been utilized as standard palliative management of distal malignant biliary obstruction (MBO). Compared to plastic stents, metal stents can provide longer-term relief of symptoms. When a large-bore metal stent is placed across the ampulla, patients are predisposed to the risk of cholangitis or stent dysfunction due to reflux of duodenal contents. To mitigate the risk of adverse events associated with the duodenobiliary reflux, efforts have been directed to development of antireflux metal stents (ARMSs). The antireflux property has been introduced through adding of an antireflux valve to the duodenal stent end. Evidence from clinical studies indicates that ARMSs may not only reduce the risk of ascending cholangitis during follow-up but also prolong stent patency time. However, the results of clinical studies testing ARMSs are inconsistent owing to heterogeneous designs of antireflux valves and stent bodies. Metal stents are increasingly indicated for benign biliary strictures and MBO in the setting of neoadjuvant chemotherapy, and therefore, research is warranted to evaluate ARMSs for those indications. Given that endoscopic ultrasound (EUS)-guided transmural biliary drainage has gained popularity, the optimal timing of placing an ARMS in relation to EUS-guided and percutaneous drainage should be investigated. Development and evaluation of ARMSs require an integrative approach utilizing phantom and animal models, measurements of stent mechanical properties, and in vivo functional study after stent placement. In this review article, we summarize updated evidence on ARMSs for MBO and discuss issues that should be addressed in future studies.

Antireflux covered metal stent for nonresectable distal malignant biliary obstruction: Multicenter randomized controlled trial

BACKGROUND AND AIM

An antireflux metal stent (ARMS) for nonresectable distal malignant biliary obstruction (MBO) may prevent recurrent biliary obstruction (RBO) as a result of duodenobiliary reflux and prolong time to RBO (TRBO). Superiority of ARMS over conventional covered self-expandable metal stents (SEMS) has not been fully examined.

METHODS

We conducted a multicenter randomized controlled trial to examine whether TRBO of an ARMS with a funnel-shaped valve was longer than that of a covered SEMS in SEMS-naïve patients. We enrolled 104 patients (52 patients per arm) at 11 hospitals in Japan. Secondary outcomes included causes of RBO, adverse events, and patient survival.

RESULTS

TRBO did not differ significantly between the ARMS and covered SEMS groups (median, 251 vs 351 days, respectively; P = 0.11). RBO as a result of biliary sludge or food impaction was observed in 13% and 9.8% of patients who received an ARMS and covered SEMS, respectively (P = 0.83). ARMS was associated with a higher rate of stent migration compared with the covered SEMS (31% vs 12%, P = 0.038). Overall rates of adverse events were 20% and 18% in the ARMS and covered SEMS groups, respectively (P = 0.97). No significant between-group difference in patient survival was observed (P = 0.26).

CONCLUSIONS

The current ARMS was not associated with longer TRBO compared with the covered SEMS. Modifications including addition of an anti-migration system are required to use the current ARMS as first-line palliative treatment of distal MBO (UMIN-CTR clinical trial registration number: UMIN000014784).