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Antireflux metal stent (ARMS) placement for distal malignant biliary obstruction. (A) Endoscopic retrograde cholangiography delineated distal biliary obstruction caused by pancreatic cancer. (B) An 8-cm-long, 10-mm-wide ARMS was successfully placed. (C) Endoscopic image showing a funnel-shaped antireflux valve attached to the distal stent end and bile flow into the duodenum.
Source publication
Background/aims:
In distal malignant biliary obstruction, an antireflux metal stent (ARMS) with a funnel-shaped valve is effective as a reintervention for metal stent occlusion caused by reflux. This study sought to evaluate the feasibility of this ARMS as a first-line metal stent.
Methods:
Patients with nonresectable distal malignant biliary ob...
Contexts in source publication
Context 1
... on the Niti-S ComVi-type SEMS (Taewoong Medical Inc., Gim- po, Korea) with an expanded polytetrafluoroethylene membrane sandwiched by two nitinol mesh layers. 21 A 7-mm-long funnel- shaped antireflux valve made of the same material was attached to the distal end, including four 5-mm-long longitudinal nitinol wires for anchorage of its shape ( Fig. 1). This valve is designed to shrink in the duodenal lumen when retrograde pressure is enhanced and thereby prevent the reflux of duodenal contents into the biliary system, while ensuring the antegrade flow of bile. Two lengths were available during the study (60 and 80 mm), and the diameter was 10 mm. The delivery system is 9-F in ...
Context 2
... standard endoscopic retrograde cholangiopancreatog- raphy techniques, ARMS were placed as described previously (Fig. 1). 22,23 A side-viewing duodenoscope (TJF-260V; Olympus Medical, Tokyo, Japan) was inserted with moderate sedation. A plastic biliary stent, if present, was removed using a snare. Biliary access was obtained via wire-guided cannulation tech- nique. 24 After the location and length of biliary obstruction was confirmed by cholangiography, ...
Similar publications
Placement of a plastic or metal stent via endoscopic retrograde cholangiopancreatography (ERCP) currently serves as the first-line procedure for obstructive jaundice and acute cholangitis. Dysfunction of the biliary stent causes recurrence of symptoms and often requires reinterventions and hospitalizations. Therefore, duration of stent patency is c...
Citations
... This impairs the function of the sphincter of Oddi and leads to SEMS occlusion due to biliary sludge or impaction of food residue [8][9][10]. To prevent duodenal biliary reflux, an SEMS with an anti-reflux valve at the lower end, an anti-reflux metal stent (ARMS), has been developed [11][12][13][14][15][16][17][18][19][20][21]; however, it is becoming clear that stent occlusion due to biliary sludge and micro-food particles cannot be prevented. ...
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.
... Many types of anti-reflux valve showed low rate of food impaction in pilot studies such as dome with cross [27] and s-shaped valve [28]. However, some types of anti-reflux valve unable to prevent food reflux [29,30] and cause stent occlusion by valve malfunction. Hu et al. [31] conducted randomized study to compare partially covered SEMS and SEMS with anti-reflux valve. ...
... Increasing outflow resistance of bile may also lead to stent migration (Hamada et al., 2019). In comparison, open valve structures such as funnel-shaped (Hamada et al., 2017;Morita et al., 2018) and S-shaped valves cannot prevent duodenobiliary reflux completely, even if they have an excellent bile drainage effect. Folding and collapse are the main causes of valve dysfunction and stent occlusion (Leong et al., 2016;Hamada et al., 2019). ...
... Bile sludge and food fiber deposited on valves negatively impacted the morphology and function of valves and affected bile flow (Morita et al., 2018). The incidence of adverse events after anti-reflux biliary stent implantation may be as high as 20% (Hamada et al., 2017). In addition, anti-reflux valves such as duckbilled (Yuan et al., 2019), nipple-shaped (Hu et al., 2014), and windsock-shaped valves (Lee et al., 2016) do not significantly improve patient survival. ...
Duodenal biliary reflux has been a challenging common problem which could cause dreadful complications after biliary stent implantation. A novel anti-reflux biliary stent with a retractable bionic valve was proposed according to the concertina motion characteristics of annelids. A 2D equivalent fluid-structure interaction (FSI) model based on the axial section was established to analyze and evaluate the mechanical performances of the anti-reflux biliary stent. Based on this model, four key parameters (initial shear modulus of material, thickness, pitch, and width) were selected to investigate the influence of design parameters on anti-reflux performance via an orthogonal design to optimize the stent. The results of FSI analysis showed that the retrograde closure ratio of the retractable valve primarily depended on initial shear modulus of material (p < 0.05) but not mainly depended on the thickness, pitch, and width of the valve (p > 0.05). The optimal structure of the valve was finally proposed with a high retrograde closing ratio of 95.89%. The finite element model revealed that the optimized anti-reflux stent possessed improved radial mechanical performance and nearly equal flexibility compared with the ordinary stent without a valve. Both the FSI model and experimental measurement indicated that the newly designed stent had superior anti-reflux performance, effectively preventing the duodenobiliary reflux while enabling the bile to pass smoothly. In addition, the developed 2D equivalent FSI model provides tremendous significance for resolving the fluid-structure coupled problem of evolution solid with large deformation and markedly shortens the calculation time.
... Such metastases have received little attention despite their frequency, perhaps because they are common occurrences in hepato-pancreato-biliary cancer. Hilar and distal biliary obstruction were caused by metastatic lymph nodes in 23% and 2%-17% (pooled average of 551 patients across eight studies: 11%) of cases treated mainly by ERCP stenting, respectively [220][221][222][223][224][225][226][227][228]. This figure may be higher for biliary obstruction in surgically altered anatomies; one report found six cases among 13 patients with surgically altered anatomies treated with metallic biliary stents (46%) [49]. ...
Malignant biliary obstruction generally results from primary malignancies of the pancreatic head, bile duct, gallbladder, liver, and ampulla of Vater. Metastatic lesions from other primaries to these organs or nearby lymph nodes are rarer causes of biliary obstruction. The most common primaries include renal cancer, lung cancer, gastric cancer, colorectal cancer, breast cancer, lymphoma, and melanoma. They may be difficult to differentiate from primary hepato-pancreato-biliary cancer based on imaging studies, or even on biopsy. There is also no consensus on the optimal method of treatment, including the feasibility and effectiveness of endoscopic intervention or surgery. A thorough review of the literature on pancreato-biliary metastases and malignant biliary obstruction due to metastatic non-hepato-pancreato-biliary cancer is presented. The diagnostic modality and clinical characteristics may differ significantly depending on the type of primary cancer. Different primaries also cause malignant biliary obstruction in different ways, including direct invasion, pancreatic or biliary metastasis, hilar lymph node metastasis, liver metastasis, and peritoneal carcinomatosis. Metastasectomy may hold promise for some types of pancreato-biliary metastases. This review aims to elucidate the current knowledge in this area, which has received sparse attention in the past. The aging population, advances in diagnostic imaging, and improved treatment options may lead to an increase in these rare occurrences going forward.
... We believe that it may be safe for the human bile duct as well because humans and swine have similar physiological and anatomical attributes [21]. In a clinical study, Lee et al. reported that an anti-reflux valve metal stent placed to reduce duodenobiliary reflux prolonged the patency period relative to that of conventional CSEMS [14]; however, this stent has not shown efficacy in additional clinical studies [22,23]. We believe that this stent will prevent food reflux but not protein or bacterial adsorption. ...
Covered self-expandable metal stents (CSEMS) are often used for palliative endoscopic biliary drainage; however, the unobstructed period is limited because of sludge occlusion. The present study aimed to evaluate the biosafety of a novel poly(2-methoxyethyl acrylate)-coated CSEMS (PMEA-CSEMS) for sludge resistance and examine its biosafety in vivo . Using endoscopic retrograde cholangiopancreatography, we placed the PMEA-CSEMS into six normal porcine bile ducts and conventional CSEMS into three normal porcine bile ducts. We performed serological examination and undecalcified histological analysis at 1, 3, and 6 months during follow-up. In the bile ducts with PMEA-CSEMS or conventional CSEMS, we observed no increase in liver enzyme or inflammatory marker levels in the serological investigations and mild fibrosis but no inflammatory response in the histopathological analyses. Thus, we demonstrated the biosafety of PMEA-CSEMS in vivo .
... Novel stents with an antireflux valve have been developed and have shown promising results in 2 RCTs [87,88]. However, latest data from Japan point out the need for further investigation and technical improvement [89]. ...
Biliary obstruction is common in pancreatobiliary malignancies and has a negative impact on the patient's quality of life, postoperative complications, and survival rates. Particularly in the last decade, there has been enormous progress regarding the diagnostic and therapeutic options in patients with malignant biliary obstruction. Endoscopy has given a new insight in this direction and novel techniques have been developed for the better characterization and treatment of malignant strictures. We herein summarize the available data on the different endoscopic techniques, and clarify their role in the diagnosis and treatment of malignant biliary obstructive disease. Finally, we propose an algorithm that can facilitate management decisions in these patients.
... Of note, in a proof-ofconcept examination utilizing oral barium after SEMS placement, the suppression of the duodenobiliary reflux via the antireflux valve was first demonstrated in the human body. 57 In parallel with their efforts, we have sought the effectiveness of an ARMS with a funnel-shaped antireflux valve 51,58 in patients who underwent covered SEMS occlusion due to the duodenobiliary reflux and thus, were considered to be at higher risk of recurrent occlusion after a reintervention. [59][60][61] In addition, our previous pilot study demonstrated the feasibility and safety of the new ARMS as a first-line SEMS for nonresectable distal MBO. ...
... [59][60][61] In addition, our previous pilot study demonstrated the feasibility and safety of the new ARMS as a first-line SEMS for nonresectable distal MBO. 58 Based on the promising results of those pilot studies, we conducted an RCT to compare the ARMS with a conventional covered SEMS. 55 A major strength of this trial was the use of a conventional covered SEMS harboring the same structure of the stent body. ...
Endoscopic retrograde cholangiopancreatography with stent placement has been utilized as standard palliative management of distal malignant biliary obstruction. 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 malignant biliary obstruction 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 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 malignant biliary obstruction and discuss issues that should be addressed in future studies.
... After cholangiography, a 10 × 80-mm antireflux covered metal stent (Niti-S Biliary Long-Covered ComVi Stent; Taewoong Medical, Gimpo, Korea) was placed through the HJS fistula (▶ Fig. 3). This stent has a 7-mm-long funnel-shaped antireflux valve designed to prevent food reflux [4]. The patient completely recovered within a few days; currently, at over 6 months after the procedure, he is continuing chemotherapy without stent dysfunction (▶ Fig. 4). ...
... The patient completely recovered within a few days; currently, at over 6 months after the procedure, he is continuing chemotherapy without stent dysfunction (▶ Fig. 4). Antireflux biliary stents have been reported to be useful in transpapillary drainage under ERCP [4,5], but their usefulness in transmural drainage under EUS is unknown. The case reported here indicates that placement of an antireflux metal stent could be useful to manage stent dysfunction following EUS-BD and achieve long-term stent patency. ...
... At presentation, most patients are not candidates for curative resection secondary to local spread or distant metastases (1)(2)(3). For those patients, percutaneous biliary stenting has become the established palliative treatment owing to its low rate of complications and mortality (3)(4)(5)(6), and this treatment contributes to the regression of symptoms and improvement in quality of life (QoL) of patients (7)(8)(9)(10)(11). ...
... In the series of studies evaluated here, in the majority of patients, stents remained patency for the remainder of the patient's life (11,19). Thus, particular efforts should be made to identify factors predictive of survival in patients with distal malignant biliary strictures. ...
... In fact, clinical evidence has not yet proven that impaired function of the main duodenal papilla triggers cholangitis or vice versa. Here, cholangitis was not the main cause of death; it has always been treated conservatively (4,11,26). Although four patients (one with cholangiocarcinoma, one with gallbladder cancer, one with gastric carcinoma, and one with pancreatic cancer) included in the current study (3.8%) developed procedure-related acute pancreatitis, the rate of occurrence of acute pancreatitis was relatively low. ...
Background/aims:
For distal malignant biliary obstruction (MBO), a percutaneous metal stent is usually inserted by the transpapillary method. However, stent-related complications and recurrent biliary obstruction following transpapillary stent placement are concerns, and survival analysis of patients with distal MBO has rarely been done.
Materials and methods:
From January 2012 to March 2016, 104 patients underwent transpapillary uncovered metal stent placement for distal MBO at our institution. Clinical success, complications, recurrent biliary obstruction rates, and predictors of survival were analyzed.
Results:
Of the total 104 patients, clinical success after stent insertion was achieved in 93 patients (90.3%). Major complications were observed in 24 patients (23.1%), which were as follows: cholangitis in 19 patients; pancreatitis in four patients; and biloma in one patient. Recurrent biliary occlusion was observed in 28 patients (26.9%). The median overall survival period was 162 days. The 3-, 6-, and 12-month overall survival rates after stent insertion were 64.4%, 41.3%, and 10.6%, respectively. Results of multivariate analysis indicated that metastatic carcinoma compared with ampullary carcinoma (HR=3.82; 95% CI, 1.30-11.24; p=0.015) and longer biliary stricture (HR=1.04; 95% CI, 1.02-1.06; p<0.001) were independent risk factors for worse survival after metal stent insertion.
Conclusion:
Transpapillary stent placement was found to be effective with acceptable complication rates for treating distal MBO. Primary tumor and length of biliary stricture were found to be statistically significant independent prognostic factors for survival.
... [25][26][27] Our previous pilot study showed the feasibility and safety of the new ARMS as a first-line SEMS for nonresectable distal MBO. 28 Therefore, we conducted a randomized controlled trial comparing stent patency times between ARMS and a conventional covered SEMS. ...
... The ARMS used in this study was a fully covered SEMS with an antireflux valve attached to the duodenal end (Taewoong Medical Inc., Gimpo, Korea). 24, 28 We used a fully covered SEMS with the same body structure (Niti-S COMVI biliary stent; Taewoong Medical Inc.) 29,30 as a control. The stent body was made with an expanded polytetrafluoroethylene (PTFE) membrane sandwiched by two nitinol mesh layers. ...
Background and Aim
An antireflux metal stent (ARMS) for nonresectable distal malignant biliary obstruction may prevent recurrent biliary obstruction (RBO) due to the duodenobiliary reflux and prolong time to RBO (TRBO). The superiority of the ARMS over conventional covered self‐expandable metal stents (SEMSs) 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. Secondary outcomes included causes of RBO, adverse events, and patient survival.
Results
We enrolled 104 patients (52 patients per arm) at 11 hospitals in Japan. The TRBO did not differ significantly between the ARMS and covered SEMS groups (median, 251 vs. 351 days, respectively; P = 0.11). RBO due to biliary sludge or food impaction was observed in 13% and 9.8% patients who received an ARMS and covered SEMS, respectively (P = 0.83). The ARMS was associated with a higher rate of stent migration compared with the covered SEMS (31% vs. 12%, P = 0.038). The 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 malignant biliary obstruction (UMIN‐CTR clinical trial registration number: UMIN000014784).
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