Novel antireflux covered metal stent for recurrent occlusion of biliary metal stents: a pilot study

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.

Effectiveness of a new approach to minimally invasive surgery in palliative treatment of patients with distal malignant biliary obstruction

BACKGROUND

Palliative endoscopic biliary drainage is the primary treatment option for the management of patients with jaundice which results from distal malignant biliary obstruction (DMBO). In this group of patients, decompression of the bile duct (BD) allows for pain reduction, symptom relief, chemotherapy administration, improved quality of life, and increased survival rate. To reduce the unfavorable effects of BD decompression, minimally invasive surgical techniques require continuous improvement.

AIM

To develop a technique for internal-external biliary-jejunal drainage (IEBJD) and assess its effectiveness in comparison to other minimally invasive procedures in the palliative treatment of patients with DMBO.

METHODS

A retrospective analysis of prospectively collected data was performed, which included 134 patients with DMBO who underwent palliative BD decompression. Biliary-jejunal drainage was developed to divert bile from the BD directly into the initial loops of the small intestine to prevent duodeno-biliary reflux. IEBJD was carried out using percutaneous transhepatic access. Percutaneous transhepatic biliary drainage (PTBD), endoscopic retrograde biliary stenting (ERBS), and internal-external transpapillary biliary drainage (IETBD) were used for the treatment of study patients. Endpoints of the study were the clinical success of the procedure, the frequency and nature of complications, and the cumulative survival rate.

RESULTS

There were no significant differences in the frequency of minor complications between the study groups. Significant complications occurred in 5 (17.2%) patients in the IEBJD group, in 16 (64.0%) in the ERBS group, in 9 (47.4%) in the IETBD group, and in 12 (17.4%) in the PTBD group. Cholangitis was the most common severe complication. In the IEBJD group, the course of cholangitis was characterized by a delayed onset and shorter duration as compared to other study groups. The cumulative survival rate of patients who underwent IEBJD was 2.6 times higher in comparison to those of the PTBD and IETBD groups and 20% higher in comparison to that of the ERBS group.

CONCLUSION

IEBJD has advantages over other minimally invasive BD decompression techniques and can be recommended for the palliative treatment of patients with DMBO.

Usefulness of duckbill‐type anti‐reflux self‐expandable metal stents for distal malignant biliary obstruction with duodenal invasion: A pilot study

Objectives

Early obstruction of a self‐expandable metal stent placed for distal malignant biliary obstruction is more likely to occur in the presence of duodenal invasion. An anti‐reflux self‐expandable metal stent (ARMS) has been developed for the purpose of preventing duodenal fluid reflux into the bile duct. In this study, we evaluated the usefulness and safety of a duckbill‐type ARMS (D‐ARMS) in the situation of duodenal invasion.

Methods

We retrospectively analyzed 10 consecutive patients who received D‐ARMS for distal malignant biliary obstruction with duodenal invasion. We evaluated non‐occlusion cholangitis, recurrent biliary obstruction (RBO), and adverse events after D‐ARMS placement.

Results

There were no cases of non‐occlusion cholangitis. RBO was observed in 2 patients (20%), and time to RBO was 236 days and 117 days, respectively. The causes of RBO were overgrowth and sludge formation. The median time to RBO was 382 days (range, 117–382 days). Only one adverse event was observed (cholecystitis).

Conclusions

D‐ARMS shows potential as an optimal ARMS.

Risk Factors of Duodenobiliary Reflux-Related Dysfunction of Covered Biliary Metal Stents after Treatment of Duodenal Stricture in Patients with Malignant Biliary and Duodenal Obstruction

Duodenal obstruction is often accompanied with unresectable malignant distal biliary obstruction in patients who have undergone biliary self-expandable metal stent (SEMS) placement. Duodenobiliary reflux (DBR) is a major cause of recurrent biliary obstruction (RBO) after covered biliary SEMS placement. We analyzed the risk factors for DBR-related SEMS dysfunction following treatment for malignant duodenal obstruction. Sixty-one patients with covered SEMS who underwent treatment for duodenal obstruction were included. We excluded patients with tumor-related stent dysfunction (n = 6) or metal stent migration (n = 1). Fifty-four patients who underwent covered biliary SEMS placement followed by duodenal metal stenting or surgical gastrojejunostomy were included. Eleven patients had DBR-related biliary SEMS dysfunction after treatment of duodenal obstruction. There was no difference between the duodenal metal stenting group and the surgical gastrojejunostomy group. Duodenal obstruction below the papilla of Vater and a score of ≤2 on the Gastric Outlet Obstruction Scoring System after treatment for duodenal obstruction were associated with DBR-related covered biliary SEMS dysfunction. Thus, creating a reliable route for ensuring good oral intake and avoiding DBR in patients with duodenal obstruction below the papilla of Vater are both important factors in preventing DBR-related covered biliary SEMS dysfunction.

External-Internal Biliary-Jejunal Drainage in Palliative Treatment of Distal Mechanical Jaundice

Введение. Метод выбора дренирования желчных протоков у пациентов с дистальной злокачественной механической желтухой (ДЗМЖ) остается дискуссионным.Цель. Разработать и внедрить в клиническую практику методику наружно-внутреннего билиарно-еюнального дренирования и сравнить ее результаты с ретроградным эндоскопическим стентированием при паллиативном лечении дистальной механической желтухи.Материалы и методы. В проспективное исследование вошло 54 пациента с ДЗМЖ: 29 пациентам выполнена разработанная методика наружно-внутреннего билиарно-еюнального дренирования (группа НВБЕД); 25 – эндоскопическое ретроградное билиарное стентирование (группа ЭРБС) с использованием непокрытых металлических стентов. НВБЕД проводилась с использованием предложенного дренажа, устанавливаемого посредством чрескожного чреспеченочного доступа, при этом конец дренажа с дистальной группой боковых отверстий размещался в начальных петлях еюнум, проксимальная группа боковых отверстий – в расширенных желчных протоках над стенозом.Точками исследования были клинический успех процедуры, частота и характер осложнений, накопленная выживаемость, накопленное время проходимости стента.Результаты. Клинический успех процедуры достигнут в группе НВБЕД у 82,1% пациентов, в группе ЭРБС – у 84,0% (р>0,05).В группе НВБЕД осложнения возникли у 5 (17,9%) пациентов, в группе ЭРБС – у 16 (64,0%) (р=0,002), в том числе холангит – у 10,3% против 36,0% (р=0,024) и панкреатит у 6,9%, против 36,0% (р=0,023) соответственно.При использовании НВБЕД накопленное выживание составило 252,3 дня (95% ДИ: 207,5–297,1) против 203,3 дня (95% ДИ: 164,5–242,1) в группе ЭРБС (р=0,072). Это мы связываем со снижением частоты холангита в группе НВБЕД. В целом накопленное выживание составило 248,9 дня (95% ДИ: 212,2–285,5) при отсутствии у пациентов эпизодов холангита против 168,8 дня (95% ДИ: 132,3–205,4) при наличии холангита (р=0,005).У пациентов с холангитом накопленное время проходимости стентов составляло 157,1 дня (95% ДИ: 132,1–182,1), при отсутствии холангита – 269,6 дня (95% ДИ: 230,3–309,0), р=0,005. У пациентов с НВБЕД закупорки просвета дренажа не наблюдали.Заключение. Предложенная методика наружно-внутреннего билиарно-еюнального дренирования при паллиативном лечении дистальной механической желтухи предпочтительнее эндоскопического ретроградного билиарного стентирования.

Introduction. The choice of bile duct drainage in patients with distal malignant obstructive jaundice (DMOJ) remains controversial.Purpose. To develop and introduce into clinical practice a technique for external-internal biliary- jejunal drainage and compare its results with retrograde endoscopic stenting in palliative treatment of DMOJ.Materials and methods. The prospective study included 54 patients with DMOJ: 29 patients underwent the developed method of external-internal biliary-jejunal drainage (NVBED group); 25 – endoscopic retrograde biliary stenting (ERPS group) using metal stents. NVBED was carried out using the proposed drainage installed by means of a percutaneous transhepatic approach, while the end of the drainage with the distal group of lateral holes was located in the initial loops of the jejunum, the proximal group of lateral holes – in the dilated bile ducts above the stenosis.The points of the study were the clinical success of the procedure, frequency and nature of complications, accumulated survival rate, accumulated time of stent patency.Results. Clinical success of the procedure was achieved in 82.1% of patients in the NVBED group, and 84.0% of patients in the ERHD group, p>0.05.In the IVBED group, complications occurred in 5 (17.9%) patients, in the ERHD group – in 16 (64.0%) patients, p=0.002, including cholangitis – in 10.3% versus 36.0% (p=0.024) and pancreatitis – in 6.9% versus 36.0% (p=0.023), respectively.When using NVBED, the cumulative survival was 252.3 days (95% CI: 207.5–297.1) versus 203.3 days (95% CI: 164.5–242.1) in the ERBS group (p=0.072). We associate this with the decrease of the incidence of cholangitis in the IVBED group. Thus, the overall cumulative survival was 248.9 days (95% CI: 212.2–285.5) in the absence of cholangitis episodes versus 168.8 days (95% CI: 132.3–205.4) in the presence of cholangitis, p=0.005.In patients with cholangitis, the cumulative time of stent patency was 157.1 days (95% CI: 132.1– 182.1); in the absence of cholangitis – 269.6 days (95% CI: 230.3–309.0, p=0.005. In patients with NVBED, the drainage lumen blockage was not observed.Conclusion. The proposed method of external-internal biliary-jejunal drainage for palliative treatment of distal obstructive jaundice is preferable in comparison with endoscopic retrograde biliary stenting.

Feasibility of biliary stenting to distal malignant biliary obstruction using a novel designed metal stent with duckbill-shaped anti-reflux valve

OBJECTIVES

Anti-reflux metal stent (ARMS) has been used to prevent recurrent biliary obstruction (RBO) due to sludge formation or food impaction. However, the most suitable ARMS remains to be identified. This study aimed to evaluate the feasibility, safety, and efficacy of biliary drainage using duckbill-shaped ARMS (D-ARMS).

METHODS

This was a multicenter, retrospective observational study conducted at three Japanese tertiary institutions. Patients with distal malignant biliary obstruction who underwent biliary stenting using D-ARMS were eligible to participate. Technical success, functional success, adverse event (AE), and time to RBO (TRBO) were evaluated.

RESULTS

Thirty patients underwent biliary stenting using D-ARMS from December 2018 to October 2019. The technical success rate and functional success rate were 93% and 87%, respectively. However, nonvisibility of the markers at the tip of the metal stent or spontaneous extension was occasionally observed, making biliary stenting using D-ARMS difficult. Early AE occurred in 10% of the patients including cholangitis and pancreatitis. During the median postprocedural observation time of 5.1 months (range, 0.8-22.8), RBO occurred in 33% and the median TRBO was 261 days. As for reintervention, D-ARMS could be extracted in 67% of the patients with RBO. However, the stent was torn off on removal in half of the patients.

CONCLUSIONS

Although some modifications are still needed, D-ARMS was feasible and safe for biliary drainage, and sufficient TRBO was achieved. Subsequent multi-institutional studies involving a larger number of patients and a longer follow-up period are warranted to validate the present results.

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.

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.

Advances in stent therapy for malignant biliary obstruction

Malignant biliary obstruction (MBO), result of pancreatobiliary diseases is a challenging condition. Most patients with MBO are inoperable at the time of diagnosis, and the disease is poorly controlled using external-beam radiotherapy and chemotherapy. Biliary stent therapy emerged as a promising strategy for alleviating MBO and prolonging life. However, physicians find it difficult to determine the optimal type of biliary stent for the palliation of MBO. Here, we review the safety and efficacy of available biliary stents, used alone or in combination with brachytherapy, photodynamic therapy and advanced chemotherapeutics, in patients with pancreatobiliary malignancies and put forward countermeasures involving stent obstruction. Furthermore, 3D-printing stents and nanoparticle-loaded stents have broad application prospects for fabricating tailor-made biliary stents.

Design and evaluation of a novel anti-reflux biliary stent with cone spiral valve

Endoscopic placement of biliary stent is a well-established palliative treatment for biliary obstruction. However, duodenobiliary reflux after stent placement has been a common problem which may lead to dreadful complications. This paper designed a novel anti-reflux biliary stent with a cone spiral valve. Fluid-Structure Interaction (FSI) simulations were established to evaluate the efficiency of the anti-reflux stent comparing with a clinically applied standard stent. According to the stress distribution of the valve, the fatigue performance in the stress concentration area was analyzed. The results show that when the antegrade flow through the valve, the cone spiral valve could stretch and open to realize adequate drainage under the normal physiological pressure of biliary tract; When the duodenal reflux through the valve, the valve would be compressed and close with a result of nearly zero at the outlet flow rate. Furthermore, the anti-reflux stent achieved improved radial mechanical performance with 2.7 times higher radial stiffness than standard stent. Finite element analysis (FEA) also indicates that compared with the standard stent, the addition of the anti-reflux valve had little negative effect on flexibility of the stent. Fatigue analysis results showed that the valve was reliable. This research provides the new stent with a cone spiral valve and proves that it is technically feasible and effective for preventing the duodenobiliary reflux while ensuring the antegrade bile flow without compromising the other biomechanical performances.

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).

Evaluation of valve function in antireflux biliary metal stents

Background

To overcome duodenobiliary reflux induced by biliary stents, antireflux valve (ARV) biliary stents have been developed and showed improvement in stent patency. However, negative study results have also been reported because stent patency may be decreased by the malfunction of ARV itself. Given such mixed results, the true efficacy of ARV remains unknown and the mechanism of its dysfunction needs to be clearly elucidated. The aim of this study was to investigate the exact mechanism of ARV dysfunction using in vitro phantom models.

Methods

Two experimental models were designed to evaluate two important environmental factors suspected to cause ARV malfunction, i.e. bile flow and pH. Three types of ARV metal stents from different companies were used for the experiments: a funnel type ARV, a windsock type ARV, and a wine glass-shaped ARV. Ten stents of each type were tested (five stents in the bile flow phantom model, and another five stents in the duodenal pH environmental model). To determine ARV malfunction, ARV-induced flow resistance was measured using a custom-made testing device. All stents from the two models were removed every 2 weeks for 12 weeks after stent insertion and were evaluated on morphological and functional changes of the ARV.

Results

Only ARV of wine glass-shaped ARV was morphologically changed due to silicone bond detachment in the bile flow model. All types of ARV were morphologically changed in the pH model. The morphological changes of ARV influenced the flow resistance. The antegrade pressure gradients were increased over time in the pH model (p < 0.05).

Conclusions

Morphological change of the ARVs may induce dysfunction of ARV metal stents, which is mainly due to duodenal pH environment. In the future, development of new ARV that is not affected by duodenal environmental factors can be expected to improve stent patency.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0878-8) contains supplementary material, which is available to authorized users.

Double-Stent System with Long Duodenal Extension for Palliative Treatment of Malignant Extrahepatic Biliary Obstructions: A Prospective Study

Objective

To investigate the technical safety and clinical efficacy of a double-stent system with long duodenal extension in patients with malignant extrahepatic biliary obstruction.

Materials and Methods

This prospective study enrolled 48 consecutive patients (31 men, 17 women; mean age, 61 years; age range, 31–77 years) with malignant extrahepatic biliary obstructions from May 2013 to December 2015. All patients were treated with a double-stent system with long duodenal covered extension (16 cm or 21 cm).

Results

The stents were successfully placed in all 48 patients. There were five (10.4%) procedure-related complications. Minor complications were self-limiting hemobilia (n = 2). Major complications included acute pancreatitis (n = 1) and acute cholecystitis (n = 2). Successful internal drainage was achieved in 42 (87.5%) patients. Median patient survival and stent patency times were 92 days (95% confidence interval [CI], 61–123 days) and 83 days (95% CI, 46–120 days), respectively. Ten (23.8%) of the 42 patients presented with stent occlusion due to food impaction with biliary sludge, and required repeat intervention. Stent occlusion was more frequent in metastatic gastric cancer patients with pervious gastrectomy, but did not reach statistical significance (p = 0.069).

Conclusion

Percutaneous placement of a double-stent system with long duodenal extension is feasible and safe. However, this stent system does not completely prevent stent occlusion caused by food reflux.

Antireflux Metal Stent for Initial Treatment of Malignant Distal Biliary Obstruction

Objectives

To compare the use of an antireflux metal stent (ARMS) with that of a conventional covered self-expandable metal stent (c-CSEMS) for initial stenting of malignant distal biliary obstruction (MDBO).

Materials and Methods

We retrospectively investigated 59 consecutive patients with unresectable MDBO undergoing initial endoscopic biliary drainage. ARMS was used in 32 patients and c-CSEMS in 27. Technical success, functional success, complications, causes of recurrent biliary obstruction (RBO), time to RBO (TRBO), and reintervention were compared between the groups.

Results

Stent placement was technically successful in all patients. There were no significant intergroup differences in functional success (ARMS [96.9%] versus c-CSEMS [96.2%]), complications (6.2 versus 7.4%), and RBO (48.4 versus 42.3%). Food impaction was significantly less frequent for ARMS than for c-CSEMS (P = 0.037), but TRBO did not differ significantly between the groups (log-rank test, P = 0.967). The median TRBO was 180.0 [interquartile range (IQR), 114.0–349.0] days for ARMS and 137.0 [IQR, 87.0–442.0] days for c-CSEMS. In both groups, reintervention for RBO was successfully completed in all patients thus treated.

Conclusion

ARMS offers no advantage for initial stent placement, but food impaction is significantly prevented by the antireflux valve.

Covered versus uncovered metal stents for malignant gastric outlet obstruction: Systematic review and meta-analysis

BACKGROUND AND AIM

Self-expandable metal stents (SEMS) are used for non-resectable malignant gastric outlet obstruction (GOO). Studies of covered versus uncovered SEMS have yielded inconsistent results as a result of heterogeneity in design and patient population. We carried out a meta-analysis to compare covered and uncovered gastroduodenal SEMS.

METHODS

Using MEDLINE, Embase, and the Cochrane database, we identified 1624 patients from 13 prospective and retrospective studies that evaluated covered and uncovered SEMS for malignant GOO and were published until October 2016. We pooled data on SEMS dysfunction, technical and clinical success, and adverse events using the fixed-effect or random-effects model.

RESULTS

Compared with uncovered SEMS, covered SEMS did not show any significant difference in stent dysfunction risk (risk ratio [RR], 1.02; 95% confidence interval [CI], 0.79-1.32). A subgroup analysis of five randomized trials suggested a trend toward a lower dysfunction risk in covered SEMS (RR, 0.63; 95% CI, 0.45-0.88). Covered SEMS were associated with a lower occlusion risk (RR, 0.44; 95% CI, 0.28-0.68), but with a higher migration risk (RR, 4.28; 95% CI, 2.89-6.34). Technical and clinical success rates were comparable between the groups. Overall adverse events tended to be more frequent in covered SEMS (RR, 1.75; 95% CI, 1.09-2.83).

CONCLUSIONS

Outcomes of covered and uncovered gastroduodenal SEMS were comparable, although the lower dysfunction rate of covered SEMS observed in the analysis of randomized trials needs further investigation. Antimigration mechanisms for covered SEMS and identification of patients who can achieve longer patency from uncovered SEMS would help improve the outcomes of gastroduodenal SEMS.

Antireflux Metal Stent as a First-Line Metal Stent for Distal Malignant Biliary Obstruction: A Pilot Study

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 obstruction were identified between April and December 2014 at three Japanese tertiary centers. We retrospectively evaluated recurrent biliary obstruction and adverse events after ARMS placement.

RESULTS

In total, 20 consecutive patients were included. The most common cause of biliary obstruction was pancreatic cancer (75%). Overall, recurrent biliary obstruction was observed in seven patients (35%), with a median time to recurrent biliary obstruction of 246 days (range, 11 to 246 days). Stent occlusion occurred in five patients (25%), the causes of which were sludge and food impaction in three and two patients, respectively. Stent migration occurred in two patients (10%). The rate of adverse events associated with ARMS was 25%: pancreatitis occurred in three patients, cholecystitis in one and liver abscess in one. No patients experienced nonocclusion cholangitis.

CONCLUSIONS

The ARMS as a first-line biliary drainage procedure was feasible. Because the ARMS did not fully prevent stent dysfunction due to reflux, further investigation is warranted.

Endoscopic management of combined malignant biliary and gastric outlet obstruction

Patients with periampullary cancer or gastric cancer often develop malignant biliary obstruction (MBO) and gastric outlet obstruction (GOO), and combined MBO and GOO is not rare in these patients. Combined MBO and GOO is classified by its location and sequence, and treatment strategy can be affected by this classification. Historically, palliative surgery, hepaticojejunostomy and gastrojejunostomy were carried out, but the current standard treatment is combined transpapillary stent and duodenal stent placement. Although a high technical success rate is reported, the procedure can be technically difficult and duodenobiliary reflux with subsequent cholangitis is common after double stenting. Recent development of endoscopic ultrasound (EUS)-guided procedures enables the management of MBO as well as GOO under EUS guidance. EUS-guided biliary drainage is now increasingly reported as an alternative to percutaneous transhepatic biliary drainage in failed endoscopic retrograde cholangiopancreatography (ERCP), and GOO is one of the major reasons for failed ERCP. In addition to EUS-guided biliary drainage, the feasibility of EUS-guided double-balloon-occluded gastrojejunostomy bypass for MBO was recently reported, and EUS-guided double stenting can potentially become the treatment of choice in the future. However, as each procedure has its advantages and disadvantages, treatment strategy should be selected based on the type of obstruction and the prognosis and performance status of the patient.

Endoscopic ultrasound-guided hepaticogastrostomy using a 6-F cystotome and 12-cm covered metal stent

An iincreasing number of reports describe endoscopic ultrasound-guided hepaticogastrostomy for malignant biliary obstruction in patients with endoscopic retrograde cholangiopancreatography failure. However, this procedure has not yet been standardized; as a result, the rate of adverse events, including bile leakage and stent migration, is relatively high. Here, we report our experience with four cases of endoscopic ultrasound-guided hepaticogastrostomy performed according to our institutional procedure.

Effectiveness of a newly designed antireflux valve metal stent to reduce duodenobiliary reflux in patients with unresectable distal malignant biliary obstruction: a randomized, controlled pilot study (with videos)

BACKGROUND AND AIMS

In patients with unresectable distal malignant biliary obstruction (MBO), endoscopic biliary drainage by using self-expandable metal stents (SEMSs) is an established palliative treatment. However, the placement of a SEMS across the major duodenal papilla prompts reflux of duodenal contents. In this study, we evaluated stent patency and duodenobiliary reflux caused by a newly developed SEMS with an antireflux valve (ARV) of the windsock type, compared with a conventional covered SEMS (cSEMS) in patients with MBO.

METHODS

Between January 2013 and September 2014, 77 patients with unresectable distal MBO were assigned randomly to groups treated with an ARV metal stent (ARVMS) group (39 patients) or a conventional cSEMS group (38 patients). In all patients, a barium meal examination was performed to evaluate reflux of barium within the SEMS and intrahepatic bile ducts. The primary outcome was stent patency duration. Secondary outcomes were the rates of technical and clinical success, duodenobiliary reflux on barium meal examination, factors causing stent dysfunction, overall patient survival, and adverse events.

RESULTS

Stent placement was technically successful in all patients. The clinical success rates were not statistically significantly different between the ARVMS and cSEMS groups (97.4% vs 97.4%, P = 1.000). Overall reflux of barium was significantly lower in the ARVMS group than the cSEMS group (7.7% vs 100%, P < .001). The cumulative duration of stent patency was significantly longer in the ARVMS group than in the cSEMS group (median ± SD, 407 ± 92 vs 220 ± 37 days; P = .013). On multivariate analysis, complete duodenobiliary reflux (odds ratio, 5.7, P = .004) and ampullary cancer (odds ratio, 8.98, P = .012) were identified as independent risk factors for stent dysfunction. There was no significant difference between the 2 groups in overall patient survival or in the incidence of adverse events.

CONCLUSIONS

The newly developed ARVMS seemed to have a superior duration of stent patency and comparable safety compared with the cSEMS. In addition, the duodenobiliary reflux related to stent dysfunction can be prevented effectively by ARVMS. Further randomized, controlled trials using large numbers of subjects are required to confirm the benefit of SEMSs with antireflux function. (Clinical trial registration number: UMIN000012734.).

Stenting in Malignant Biliary Obstruction

Decompression of the biliary system in patients with malignant biliary obstruction has been widely accepted and implemented as part of the care. Despite a wealth of literature, there remains a significant amount of uncertainty as to which approach would be most appropriate in different clinical settings. This review covers stenting of the biliary system in cases of resectable or palliative malignant biliary obstruction, potential candidates for biliary drainage, technical aspects of the procedure, as well as management of biliary stent dysfunction. Furthermore, periprocedural considerations including proper mapping of the location of obstruction and the use of antibiotics are addressed.

Antireflux metal stent with an antimigration system for distal malignant biliary obstruction: a feasibility pilot study

An antireflux metal stent (ARMS) for distal malignant biliary obstruction has been reported to be useful, but the effectiveness of a flared-end structure to prevent migration on ARMS remains unclear. To evaluate the feasibility of a newly designed ARMS with both ends flared, 8 patients with covered metal stent occlusion due to sludge or food impaction were enrolled. ARMS were placed successfully after endoscopic removal of the occluded stents in all patients, and no procedure-related complication was observed. The median time to recurrent biliary obstruction was 71 days. ARMS occlusion occurred in 3 (38%) patients (sludge in 2 patients and hemobilia in 1). ARMS migration occurred in 1 (13%) patient. As a late complication, cholecystitis occurred in 1 (13%) patient. In conclusion, our newly designed ARMS with an antimigration system was technically feasible and safe, and a further investigation is warranted to evaluate the effectiveness of the current antimigration system.

Comparison of uncovered stent placement across versus above the main duodenal papilla for malignant biliary obstruction

PURPOSE

To evaluate the differences in efficiency and complications of metal stent insertion across versus above the main duodenal papilla (MDP) in patients with malignant obstruction of the common bile duct (CBD).

MATERIALS AND METHODS

Records of 98 consecutive patients who underwent stent insertion for malignant CBD obstruction between 2004 and 2010 were retrospectively reviewed. Fifty-one patients (group 1) and 47 patients (group 2) were treated with stent insertion across and above the MDP, respectively. Primary stent patency, overall survival, complications, and changes in serum bilirubin level following stent insertion were assessed.

RESULTS

Infection appeared in 12 and four patients, respectively, in groups 1 and 2. The respective mean primary stent patency times were 307.8 days ± 20.2 and 490.7 days ± 40.7, and mean survival times were 245.1 days ± 17.4 and 286.3 days ± 20.2. Bilirubin reduction rates were 55.7% ± 16.6 and 61.1% ± 13.7 at 1 week and 84.2% ± 5.7 and 86.2% ± 5.7 at 1 month in groups 1 and 2, respectively. In group 2, the rate of infection was significantly lower (P = .044) and primary stent patency was longer (P = .019). However, there was no significant difference between groups in survival time (P = .074) or bilirubin reduction rate at 1 week (P = .083) or 1 month (P = .082).

CONCLUSIONS

Bile stent insertion above the MDP may achieve longer stent patency and a lower infection rate compared with placement across the MDP. For patients with malignant CBD obstruction, biliary stents should be placed above the papilla if papillary lesions are not invaded.