Safety and efficacy of lumen-apposing metal stents versus plastic stents to treat walled-off pancreatic necrosis: systematic review and meta-analysis

Effect of Plastic Stents Following Lumen-Apposing Metal Stent Placement on Recurrence of Pancreatic Fluid Collections in Disconnected Pancreatic Duct Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

Lumen-apposing metal stents (LAMS) are preferred to initial drainage in pancreatic fluid collections (PFCs) patients with disconnected pancreatic duct syndrome (DPDS) in recent years. However, unlike plastic stents, the long-term placement of LAMS is not recommended due to a high risk of local complications. This meta-analysis attempted to evaluate the effect of using plastic stents for prolonged drainage after LAMS removal on recurrence of PFCs in DPDS.

METHODS

A comprehensive literature search was conducted from inception until January 2023, to identify articles investigating the endoscopic ultrasound (EUS)-guided treatment of plastic stents compared with no plastic stents following LAMS removal in patients with PFCs and DPDS. The primary outcome measures included recurrence of PFCs and need for reintervention.

RESULTS

We identified 3 eligible articles including 520 patients with PFCs, 246 of whom with DPDS. There was a total of 143 and 103 patients in the plastic stents group and in the no plastic stents group, respectively. The plastic stents group exhibited a lower rate of PFCs recurrence following LAMS removal after PFCs resolution compared with the no plastic stents group (OR 0.15; 95% CI 0.03-0.75; P=0.02). However, there was no difference in the rates of reintervention between the two groups (OR 0.52; 95% CI 0.15-1.83; P=0.31). There was no severe adverse events and mortality associated with stent placement or exchange in all patients.

CONCLUSION

Deployment of plastic stents for long-term drainage after LAMS replacement can decrease the risk of PFCs recurrence in patients with DPDS following resolution, but it does not impact reintervention rates.

Impact of long-term transmural plastic stents on recurrence after endoscopic treatment of walled-off pancreatic necrosis

BACKGROUND

Endoscopic transmural drainage (ETD) using double-pigtail stents (DPSs) is a well-established treatment for walled-off pancreatic necrosis (WON). This study aimed to compare outcomes in patients undergoing ETD with DPSs left indwelling versus those where stents were removed or migrated.

METHODS

This retrospective multicenter cohort study included patients with WON who underwent ETD using DPSs between July 2001 and December 2019. The primary outcome was recurrence of a pancreatic fluid collection (PFC). Secondary outcomes were long-term complications and recurrence-associated factors. Competing risk regression analysis considered DPS removal or migration as time-varying covariates.

RESULTS

Among 320 patients (median age 58; 36% women), DPSs were removed in 153 (47.8%), migrated spontaneously in 27 (8.4%), and remained indwelling in 140 (43.8%). PFC recurrence was observed in 57 patients (17.8%): after removal (n = 39; 25.5%); after migration (n = 4; 14.8%); in patients with indwelling DPSs (n = 14; 10.0%). In 25 patients (7.8%), drainage of recurrent PFC was indicated. Risk factors for recurrence were DPS removal or migration (hazard ratio [HR] 3.45, 95%CI 1.37-8.70) and presence of a disconnected pancreatic duct (HR 5.08, 95%CI 1.84-14.0).

CONCLUSIONS

Among patients who undergo ETD of WON, leaving DPSs in situ seems to lower the risk of recurrent fluid collections, without any long-term DPS-related complications. These results suggest that DPSs should not be routinely removed and can be safely left indwelling indefinitely.

Endoscopic Ultrasound-Guided Drainage of Pancreatic Fluid Collections: Not All Queries Are Already Solved

Pancreatic fluid collections (PFCs) are well-known complications of acute pancreatitis. The overinfection of these collections leads to a worsening of the prognosis with an increase in the morbidity and mortality rate. The primary strategy for managing infected pancreatic necrosis (IPN) or symptomatic PFCs is a minimally invasive step-up approach, with endosonography-guided (EUS-guided) transmural drainage and debridement as the preferred and less invasive method. Different stents are available to drain PFCs: self-expandable metal stents (SEMSs), double pigtail stents (DPPSs), or lumen-apposing metal stents (LAMSs). In particular, LAMSs are useful when direct endoscopic necrosectomy is needed, as they allow easy access to the necrotic cavity; however, the rate of adverse events is not negligible, and to date, the superiority over DPPSs is still debated. Moreover, the timing for necrosectomy, the drainage technique, and the concurrent medical management are still debated. In this review, we focus attention on indications, timing, techniques, complications, and particularly on aspects that remain under debate concerning the EUS-guided drainage of PFCs.

Endoscopic management of pancreatic collections. Endoscopic Ultrasound Group from the Spanish Society of Digestive Endoscopy (GSEED-USE) Clinical Guidelines

Acute pancreatitis is associated with significant morbidity and mortality. It can develop complications such as fluid collections and necrosis. Infection of necrosis occurs in about 20-40% of patients with severe acute pancreatitis, and is associated with organ failure and worse prognosis. In the past years, the treatment of pancreatic collections has shifted from open surgery to minimally invasive techniques, such as endoscopic ultrasound guided drainage. These guidelines from a selection of experts among the Endoscopic Ultrasound Group from the Spanish Society of Gastrointestinal Endoscopy (GSEED-USE) have the purpose to provide advice on the management of pancreatic collections based on a thorough review of the available scientific evidence. It also reflects the experience and clinical practice of the authors, who are advanced endoscopists or clinical pancreatologists with extensive experience in managing patients with acute pancreatitis.

Endoscopic ultrasound-guided drainage of pancreatic collections with dedicated metal stents: A nationwide, multicenter, propensity score-matched comparison

BACKGROUND

The new dedicated stents for endoscopic ultrasound (EUS)-guided transluminal drainage of peri‑pancreatic fluid collections (PFCs) demonstrated optimal efficacy and safety profiles.

AIMS

This study aimed to evaluate the safety, technical and clinical success, and recurrence rate of PFCs drained with Lumen Apposing Metal Stent (LAMS) or Bi-Flanged Metal Stent (BFMS).

METHODS

Data from a multicenter series of PFCs treated with LAMS or BFMS at 30 Italian centers during a 5-year period were retrieved. The rate of adverse events (AEs), technical success, clinical success, PFC recurrence were evaluated. To overcome biases, a 1-to-1 match was created using propensity score analysis.

RESULTS

Out of 476 patients, 386 were treated with LAMS and 90 with BFMS, with a median follow-up of 290 days (95% CI 244 to 361). Using propensity score matching, 84 patients were assigned to each group. The incidence of AEs did not differ between the two stents (13.1% versus 15.5%, p = 0.29), mainly bleeding or recurrence rate (4.7% versus 3.5%, p = 1). Technical and clinical success in the BFMS and LAMS groups were 92% versus 95% (p = 0.36) and 91% versus 94% (p = 0.64), respectively.

CONCLUSION

Our study demonstrates that LAMS and BFMS have comparable safety profiles with similar technical and clinical success rates for EUS-guided PFC drainage.

Lumen-apposing metal stents with or without coaxial plastic stent placement for the management of pancreatic fluid collections

BACKGROUND AND AIMS

Coaxial double-pigtail plastic stent (DPPS) placement is often performed within lumen-apposing metal stents (LAMSs) for drainage of pancreatic fluid collections (PFCs) to prevent adverse events (AEs) such as stent occlusion and bleeding. This study compares the safety and outcomes of LAMSs alone versus LAMSs with coaxial DPPSs for PFC management.

METHODS

Patients undergoing drainage of a PFC with LAMSs were retrospectively identified and categorized as LAMS or LAMS/DPPS based on initial drainage strategy. The AE rate, AE type, and clinical success were extracted by chart review.

RESULTS

One hundred eighty-five individuals (83 LAMS, 102 LAMS/DPPS) were identified. No significant differences were found in rates of clinical success (75.9% LAMS vs 69.6% LAMS/DDPS, P = .34) or overall AEs (15.7% LAMS vs 15.7% LAMS/DPPS, P = .825).

CONCLUSIONS

In this comparative single-center study, placement of a coaxial DPPS for drainage of PFCs with LAMSs did not affect rates of AEs or clinical success.

Clinical application and follow-up of electrocautery-enhanced lumen-apposing metal stents for endoscopic ultrasonography-guided interventions

Aim: The lumen-apposing metal stent (LAMS) is a new device that expands the scope of gastrointestinal intervention under endoscopy. LAMS was initially used for the treatment of pancreatic fluid collections (PFCs), but is increasingly being used off-label. The electrocautery system simplifies the deployment of LAMS, making it more suitable for off-label situations. The short-term results of electrocautery-enhanced lumen-apposing metal stents (ECE-LAMS) are satisfactory; however, the long-term follow-up results must be evaluated. The aim of this article is to review the expanded clinical application of ECE-LAMS, the clinical value of on-label and off-label use, and follow-up results.Methods: After searching in PubMed and Web of Science databases using 'electrocautery-enhanced lumen-apposing metal stents' and 'endoscopic ultrasonography (EUS) -guided interventions' as keywords, studies related were compiled and examined.Results: ECE-LAMS are widely used for on-label and off-label situations. The short-term and long-term results of ECE-LAMS are satisfactory, but there are still some studies that do not agree with this viewpoint.Conclusion: The clinical application of ECE-LAMS is relatively safe and reliable but more well-designed randomized trials and prospective studies are needed to evaluate the impact of this technology on therapeutic EUS, to improve the safety and success rate of EUS-guided LAMS implantation, and to expand its application in other indications.

Real-life Indications and Outcome of Electrocautery-enhanced Lumen-apposing Metal Stents in a Tertiary Center

PURPOSE

Electrocautery-enhanced lumen-apposing stents (EC-LAMS) were originally designed for the drainage of the gallbladder, bile duct, and pancreas pseudocysts. Throughout the years, several off-label indications were established. This study aims to evaluate the indication, safety, efficacy, and outcome of all LAMS implanted in a single tertiary referral center.

METHODS

From April 2016 to April 2022, all patients undergoing LAMS placement in a single tertiary center were included. We present a detailed analysis of indications, success rates, and complications based on a retrospective analysis of our prospectively maintained database.

RESULTS

A total of 86 stents were placed in 77 patients between April 2016 and April 2022. Indications were walled-off pancreatic necrosis (25.6%), bile duct obstructions (16.3%), acute cholecystitis (15.1%), pancreas pseudocysts (15.1%), postoperative collections (10.5%), postoperative pancreatic fistulas (9.3%), and gastro-gastrostomy/jejunostomy (8.1%) to enable to perform an endoscopic retrograde cholangiopancreatography in patients with gastric bypass. Technical success was 97.7% (84 out of 86). A total of 10 (11.7%) adverse events were observed. In 3 patients (3.5%), severe complications occurred, which required acute surgery; one displacement was closed through clips. In 7 patients (8.2%), bleedings occurred during necrosectomy or from mucosal erosions at the stent side, respectively, that were treated with endoclips.

CONCLUSIONS

EC-LAMS are safe and show a high technical success rate in all indications. In everyday clinical practice, the main indications are hepato-pancreato-biliary, and therefore an hepato-pancreato-biliary-surgical department should have EC-LAMS in their armamentarium.

Mishaps with EUS-guided lumen-apposing metal stents in therapeutic pancreatic EUS: Management and prevention

EUS-guided interventions have become widely accepted therapeutic management options for drainage of peripancreatic fluid collections. Apart from endosonographic skills, EUS interventions require knowledge of the endoscopic stenting techniques and familiarity with the available stents and deployment systems. Although generally safe and effective, technical failure of correct stent positioning or serious adverse events can occur, even in experts' hands. In this article, we address common and rare adverse events in transmural EUS-guided stenting, ways to prevent them, and management options when they occur. Knowing the risks of what can go wrong combined with clinical expertise, high levels of technical skills, and adequate training allows for the safe performance of EUS-guided drainage procedures. Discussing the procedural risks and their likelihood with the patient is a fundamental part of the consenting process.

A Protocolized Management of Walled-Off Necrosis (WON) Reduces Time to WON Resolution and Improves Outcomes

BACKGROUND AND AIMS

Patients with infected or symptomatic walled-off necrosis (WON) have high morbidity and health care utilization. Despite the recent adoption of nonsurgical treatment approaches, WON management remains nonalgorithmic. We investigated the impact of a protocolized early necrosectomy approach compared with a nonprotocolized, clinician-driven approach on important clinical outcomes.

METHODS

Records were reviewed for consecutive patients with WON who underwent a protocolized endoscopic drainage with a lumen-apposing metal stent (cases), and for patients with WON treated with a lumen-apposing metal stent at the same tertiary referral center who were not managed according to the protocol (control subjects). The protocol required repeat cross-sectional imaging within 14 days after lumen-apposing metal stent placement, with regularly scheduled endoscopic necrosectomy if WON diameter reduction was <50%. Control patients were treated according to their clinician's preference without an a priori strategy. Inverse probability of treatment weighting-adjusted analysis was used to evaluate the influence of being in the protocolized group on time to resolution.

RESULTS

A total of 24 cases and 47 control subjects were included. There were no significant differences in baseline characteristics. Although numbers of endoscopies and necrosectomies were similar, cases had lower adverse event rates, shorter intensive care unit stay, and required nutritional support for fewer days. On matched multivariate Cox regression, cases had earlier WON resolution (hazard ratio, 5.73; 95% confidence interval, 2.62-12.5). This was confirmed in the inverse probability of treatment weighting-adjusted analysis (hazard ratio, 3.4; 95% confidence interval, 1.92-6.01).

CONCLUSIONS

A protocolized strategy resulted in faster WON resolution compared with a discretionary approach without the need for additional therapeutic interventions, and with a better safety profile and decreased health care utilization.

Self-Expandable Metal Stent (SEMS) Versus Lumen-Apposing Metal Stent (LAMS) for Drainage of Pancreatic Fluid Collections: A Randomized Clinical Trial

Background and aim Endoscopic ultrasound (EUS)-guided drainage is the gold standard approach for the treatment of encapsulated pancreatic collections (EPCs) including pseudocyst and walled-off pancreatic necrosis (WON), and is associated with an equivalent clinical efficacy to surgical drainage with fewer complications and less morbidity. Drainage may be achieved via several types of stents including a fully covered self-expandable metallic stent (SEMS) and lumen-apposing metal stent (LAMS). However, to date there have been no randomized trials to compare these devices. This study aimed to compare the efficacy and safety of the SEMS versus LAMS for EUS-guided drainage of EPCs. Methods A phase IIB randomized trial was designed to compare the SEMS versus LAMS for the treatment of EPCs. Technical success, clinical success, adverse events (AEs), and procedure time were evaluated. A sample size of 42 patients was determined. Results There was no difference between the two groups in technical (LAMS 80.95% vs 100% SEMS, p=0.107), clinical (LAMS 85.71% vs 95.24% SEMS, p=0.606) or radiological success (LAMS 92.86% vs 83.33% SEMS, p=0.613). There was no difference in AEs including stent migration rate and mortality. The procedure time was longer in the LAMS group (mean time 43.81 min versus 24.43 min, p=0.001). There was also a difference in the number of intra-procedure complications (5 LAMS vs 0 SEMS, p=0.048). Conclusion SEMS and LAMS have similar technical, clinical, and radiological success as well as AEs. However, SEMS has a shorter procedure time and fewer intra-procedure complications compared to non-electrocautery-enhanced LAMS in this phase IIB randomized controlled trial (RCT). The choice of the type of stent used for EUS drainage of EPCs should consider device availability, costs, and personal and local experience.

Endoscopic management of pancreatic walled-off necrosis

Pancreatic walled-off necrosis (WON) is a complication of severe pancreatitis. Endoscopic transmural drainage has been recognized as the first-line treatment for pancreatic fluid collections. Endoscopy offers a minimally invasive approach when compared to surgical drainage. Today, endoscopists may choose to use self-expanding metal stents, pigtail stents, or lumen-apposing metal stents to facilitate drainage of fluid collections. Current data suggest that all 3 approaches yield similar outcomes. It was previously thought that drainage should be performed 4 weeks from the initial event of pancreatitis, theoretically allowing the capsule to mature. However, current data show that both early (<4 weeks) and standard (≥4 weeks) endoscopic drainage are comparable. Herein, we provide an up-to-date state-of-the-art review of the indications, techniques, innovations, outcomes, and future perspectives following drainage of pancreatic WON.

Novel classification system for walled-off necrosis: a step toward standardized nomenclature and risk-stratification framework

BACKGROUND AND AIMS

The optimal therapeutic approach for walled-off necrosis (WON) is not fully understood, given the lack of a validated classification system. We propose a novel and robust classification system based on radiologic and clinical factors to standardize the nomenclature, provide a framework to guide comparative effectiveness trials, and inform the optimal WON interventional approach.

METHODS

This was a retrospective analysis of patients who underwent endoscopic management of WON by lumen-apposing metal stent placement at a tertiary referral center. Patients were classified according to the proposed QNI classification system: quadrant ("Q"), represented an abdominal quadrant distribution; necrosis ("N"), denoted by the percentage of necrosis of WON; and infection ("I"), denoted as positive blood culture and/or systemic inflammatory response syndrome reaction with a positive WON culture. Two blinded reviewers classified all patients according to the QNI system. Patients were then divided into 2 groups: those with a lower QNI stratification (≤2 quadrants and ≤30% necrosis; group 1) and those with a higher stratification (≥3 quadrants, 2 quadrants with ≥30% necrosis, or 1 quadrant with >60% necrosis and infection; group 2). The primary outcome was mean time to WON resolution. Secondary procedural and clinical outcomes between the groups were compared.

RESULTS

Seventy-one patients (75% men) were included and stratified by the QNI classification; group 1 comprised 17 patients and group 2, 54 patients. Patients in group 2 had a higher number of necrosectomies, longer hospital stays, and more readmissions. The mean time to resolution was longer in group 2 than in group 1 (79.6 ± 7.76 days vs 48.4 ± 9.22 days, P = .02). The mortality rate was higher in group 2 (15% vs 0%, P = .18).

CONCLUSIONS

Despite the heterogeneous nature of WON in severe acute pancreatitis, a proposed QNI system may provide a standardized framework for WON classification to inform clinical trials, risk-stratify the disease course, and potentially inform an optimal management approach.

Double guidewire technique stabilization procedure for endoscopic ultrasound-guided hepaticogastrostomy involving modifying the guidewire angle at the insertion site

BACKGROUND AND AIMS

Endoscopic ultrasonography-guided hepaticogastrostomy (EUS-HGS) is often performed using a single guidewire (SGW), but the efficacy of the double guidewire (DGW) technique during endoscopic ultrasonography-guided biliary drainage has been reported. We evaluated the efficacy of the DGW technique for EUS-HGS, focusing on the guidewire angle at the insertion site.

METHODS

This retrospective cohort study included consecutive patients who underwent EUS-HGS between April 2012 and March 2021. We measured the guidewire angle at the insertion site using still fluoroscopic imaging. We compared the clinical outcomes of EUS-HGS with the DGW and SGW techniques. The factors associated with successful cannula insertion, need for additional fistula dilation and adverse event rate were assessed by a logistic regression multivariable analysis.

RESULTS

The DGW group showed higher technical (p = 0.020) and clinical success rates (p = 0.016) than the SGW group, which showed more adverse events (p = 0.017) than the DGW group. Successful cannula insertion was associated with a guidewire angle > 137° and an uneven double-lumen cannula. The DGW technique made the guidewire angle obtuse at the insertion site (p < 0.0001). A guidewire angle ≤ 137° (OR, 35.6; 95% CI, 1.70-744; p = 0.0045) and intrahepatic bile duct diameter of the puncture site ≤ 3.0 mm (OR, 14.4; 95% CI, 1.37-152; p = 0.0056) were risk factors for needing additional fistula dilation in a multivariate analysis, and additional dilation was a significant predictive factor for adverse events (OR, 8.3; 95% CI, 0.9-77; p = 0.026).

CONCLUSIONS

The DGW technique can modify the guidewire angle at the insertion site and facilitate stent deployment with few adverse events.

Nomogram for prediction of adverse events after lumen-apposing metal stent placement for drainage of pancreatic fluid collections

OBJECTIVES

To generate a prognostic model based on a nomogram for adverse event (AE) prediction after lumen-apposing metal stents (LAMS) placement in patients with pancreatic fluid collections (PFC).

METHODS

Data from a large multicenter series of PFCs treated with LAMS placement were retrieved. AE (overall and excluding mild events) prediction was calculated through a logistic regression model and a nomogram was created and internally validated after bootstrapping. Results were expressed in terms of odds ratio (OR) and 95% confidence interval (CI). Discrimination was assessed by c-statistics and calibrated by comparing deciles of predicted and observed ORs.

RESULTS

Overall, 516 patients were included (males 68%, mean age 61.6 ± 15.2 years). PFCs were predominantly walled-off necrosis (52.1%). Independent predictors of AE occurrence were injury of main pancreatic duct (OR in the case of leak 2.51, 95% CI 1.06-5.97, P = 0.03; OR in the case of complete disruption 2.61, 1.53-4.45, P = 0.01), abnormal vessels (OR in the case of perigastric varices 2.90, 1.31-6.42, P = 0.008; OR in the case of pseudoaneurysm 2.99, 1.75-11.93, P = 0.002), using a multigate technique (OR 3.00, 1.28-5.24; P = 0.05), and need of percutaneous drainage (OR 2.81, 1.03-7.65, P = 0.04). By nomogram, a score beyond 200 points corresponded to a 50% probability of AE occurrence. The model was confirmed even when excluding mild AEs and it showed optimal discrimination (c-index 76.8%, 95% CI 74-79), confirmed after internal validation.

CONCLUSION

Patients with preprocedural evidence of pancreatic duct leak/disruption, vessel alteration, requiring percutaneous drainage or a multigate technique are at higher risk for AE.

Infection of (Peri-)Pancreatic Necrosis Is Associated with Increased Rates of Adverse Events during Endoscopic Drainage: A Retrospective Study

Pancreatic necroses are a major challenge in the treatment of patients with pancreatitis, causing high morbidity. When indicated, these lesions are usually drained endoscopically using plastic or metal stents. However, data on factors associated with the occurrence of failure or adverse events during stent therapy are scarce. We retrospectively analyzed all adverse events and their associated features which occurred in patients who underwent a first-time endoscopic drainage of pancreatic necrosis from 2009 to 2019. During the observation period, a total of 89 eligible cases were identified. Adverse events occurred in 58.4% of the cases, of which 76.9% were minor (e.g., stent dislocation, residual lesions, or stent obstruction). However, these events triggered repeated interventions (63.5% vs. 0%, p < 0.001) and prolonged hospital stays (21.0 [11.8−63.0] vs. 14.0 [7.0−31.0], p = 0.003) compared to controls without any adverse event. Important factors associated with the occurrence of adverse events during endoscopic drainage therapy were positive necrosis cultures (6.1 [2.3−16.1], OR [95% CI], p < 0.001) and a larger diameter of the treated lesion (1.3 [1.1−1.5], p < 0.001). Superinfection of pancreatic necrosis is the most significant factor increasing the likelihood of adverse events during endoscopic drainage. Therefore, control of infection is crucial for successful drainage therapy, and future studies need to consider superinfection of pancreatic necrosis as a possible confounding factor when comparing different therapeutic modalities.

Endoscopic step up: When and how

The management of (peri)pancreatic collections has undergone a paradigm shift from open surgical drainage to minimally invasive endoscopic, percutaneous, or surgical interventions. Minimally invasive interventions are associated with less morbidity and mortality compared to open necrosectomy. The (peri)pancreatic collections are currently treated with a “step-up approach” of an initial drainage procedure followed, if necessary, by a more invasive debridement. The step-up approach for management of (peri)pancreatic collections is mainly of two types, namely, surgical and endoscopic. Surgical step up includes initial image-guided percutaneous catheter drainage followed, if necessary, by minimally invasive video-assisted retroperitoneal debridement. Endoscopic step-up approach includes endoscopic transluminal drainage followed, if necessary by direct endoscopic necrosectomy. The development of endoscopic ultrasound and lumen apposing metal stents (LAMSs) has revolutionized the endoscopic management of (peri)pancreatic collections. Compared to surgical step-up approach, endoscopic step-up treatment approach has been reported to be associated with less new-onset organ failure, pancreatic fistula, enterocutaneous fistula, or perforation of visceral organ and shorter hospital/intensive care unit stay. This review will mainly focus on indications, techniques, timing, and recent advances related to endoscopic step-up approach in management of symptomatic(peri)pancreatic collections.

Impact of transmural plastic stent on recurrence of pancreatic fluid collection after metal stent removal in disconnected pancreatic duct: a randomized controlled trial

BACKGROUND

Disconnected pancreatic duct (DPD) after development of walled-off necrosis (WON) predisposes to recurrent (peri)pancreatic fluid collection (PFC). In this randomized controlled trial, we compared plastic stents with no plastic stent after removal of a large-caliber metal stent (LCMS) on incidence of recurrent PFCs in DPD. METHODS : Consecutive patients with WON who underwent endoscopic ultrasound (EUS)-guided drainage with LCMS between September 2017 and March 2020 were screened for eligibility. At LCMS removal (4 weeks after drainage), patients with DPD were randomized to plastic stent or no stent groups. The primary outcome was incidence of recurrent PFC at 3 months. Secondary outcomes were technical success of plastic stent deployment, adverse events, stent migration, and recurrence of PFC at 6 and 12 months.

RESULTS

236 patients with WON underwent EUS-guided drainage using LCMS, and 104 (males 94, median age 34 years (interquartile range [IQR] 26-44.7) with DPD were randomized into stenting (n = 52) and no-stenting (n = 52) groups. Plastic stent deployment was successful in 88.5 %. Migration occurred in 19.2 % at median follow-up of 8 months (IQR 2.5-12). Recurrent PFCs occurred in six patients at 3 months (stent n = 3, no stent n = 3). There was no significant difference in PFC recurrence between the two groups at 3, 6, and 12 months. Reintervention was required in seven patients with recurrent PFCs, with no significant difference between the two groups.

CONCLUSION

In patients with WON and DPD, deployment of plastic stents after LCMS removal did not reduce recurrence of PFC.

Disconnected pancreatic duct syndrome and outcomes of endoscopic ultrasound-guided treatment of pancreatic fluid collections: Systematic review and meta-analysis

BACKGROUND

Disconnected pancreatic duct syndrome (DPDS) frequently occurs in patients with acute necrotizing pancreatitis and resultant pancreatic fluid collection (PFC). We performed a systematic review and meta-analysis to evaluate outcomes of endoscopic ultrasound-guided treatment of PFCs according to the presence of DPDS.

METHODS

Using PubMed, Embase, and the Cochrane database, we identified clinical studies published until January 2021 with data comparing outcomes of endoscopic ultrasound-guided drainage of PFCs between DPDS and non-DPDS patients. We pooled data on technical and clinical success rates, PFC recurrence, and adverse events using the random-effects model.

RESULTS

We identified five eligible articles including 941 PFC patients treated with endoscopic ultrasound-guided interventions. Clinical success, defined as resolution of the PFC and symptoms, was achieved in a majority of the cases irrespective of DPDS (pooled odds ratio [OR] comparing DPDS to non-DPDS patients, 0.77; 95% confidence interval [CI] 0.33-1.81). Compared to patients without DPDS, patients with DPDS were more likely to undergo PFC recurrence (pooled OR 6.72; 95% CI 2.72-16.6) after clinical resolution of PFC. Prolonged plastic stent placement following the clinical resolution was more frequently performed in DPDS patients than in non-DPDS patients (pooled OR 15.9; 95% CI 2.76-91.9). No statistically significant difference was observed between the groups in terms of the rate of technical success, adverse events, or mortality.

CONCLUSION

Disconnected pancreatic duct syndrome was associated with higher rate of PFC recurrence after successful endoscopic treatment of PFCs. Future studies should evaluate effectiveness and optimal duration of long-term placement of transmural plastic stents for PFCs with DPDS.

Lumen Apposition: A Changing Landscape in Therapeutic Endoscopy

The concept of endoscopic lumen apposition has seen a dramatic shift in the last several decades. Early natural orifice trans-luminal endoscopic surgery (NOTES) concepts have transformed into specialized lumen-apposing metal stents (LAMSs) and delivery devices, which provide endoscopists a minimally invasive alternative to surgical intervention. These LAMSs have become the bedrock of therapeutic endoscopy and provide treatment for a wide spectrum of gastrointestinal disorders. In this review, we summarize the changing landscape of therapeutic endoscopy by highlighting the use of LAMS and future directions as well as alternative devices to achieve lumen apposition.

Lumen Apposition: A Changing Landscape in Therapeutic Endoscopy

The concept of endoscopic lumen apposition has seen a dramatic shift in the last several decades. Early natural orifice trans-luminal endoscopic surgery (NOTES) concepts have transformed into specialized lumen-apposing metal stents (LAMSs) and delivery devices, which provide endoscopists a minimally invasive alternative to surgical intervention. These LAMSs have become the bedrock of therapeutic endoscopy and provide treatment for a wide spectrum of gastrointestinal disorders. In this review, we summarize the changing landscape of therapeutic endoscopy by highlighting the use of LAMS and future directions as well as alternative devices to achieve lumen apposition.

Microbial Spectra and Clinical Outcomes from Endoscopically Drained Pancreatic Fluid Collections: A Descriptive Cohort Study

Pancreatic pseudocyst (PC) and walled-off necrosis (WON) are dreaded complications of acute pancreatitis. Standard therapy consists of endoscopic ultrasound-guided transmural placement of stents to expedite resolution through internal drainage of fluids or necrotic material. Either double pigtail plastic stents (DPPS) or lumen-apposing metal stents (LAMS), or a combination of both, are available for this purpose. The objective of this study was to examine the impact of different stent types on infection rates in addition to clinical outcome measures such as periprocedural adverse events. We conducted a retrospective study comprising 77 patients who had undergone endoscopic drainage for PC or WON in a pancreatitis tertiary referral center. Analysis revealed that both bacterial and fungal infections occurred more frequently in patients treated with LAMS with or without DPPS compared to DPPS only. The use of antibiotics and antimycotics followed the same pattern. Furthermore, a prolonged length of hospital stay and a higher likelihood of transfer to an intermediate care unit were observed in patients with LAMS with or without DPPS. These differences were eliminated if only WON patients were analyzed. Our data imply that the clinical course is primarily influenced by the complexity of the pancreatic fluid collection (PFC) itself rather than the stent type. Prospective large-scale cohort studies are mandatory to underpin these findings.

Partially covered self-expandable metal stent with antimigratory single flange plays important role during EUS-guided hepaticogastrostomy

Background and study aims  Stent migration into the abdominal cavity, which can occur due to stent shortening or stomach mobility, is a critical adverse event (AE) in EUS-HGS. To prevent this AE due to stent shortening, a novel, partially covered self-expandable metal stent with an antimigratory single flange has recently become available in Japan. The present study evaluated the clinical feasibility and safety of EUS-HGS using this novel stent. Patients and methods  We measured stent length in the abdominal cavity and the luminal portion after EUS-HGS using computed tomography (CT) performed 1 day after EUS-HGS (early phase). To evaluate stent shortening and the influence of stomach mobility, we also measured stent length at the same sites on CT performed at least 7 days after EUS-HGS (late phase). Results  Thirty-one patients successfully underwent EUS-HGS using this stent. According to CT in the early phase, stent length in the abdominal cavity was 7.13 ± 2.11 mm and the length of the luminal portion was 53.3 ± 6.27 mm. Conversely, according to CT in the late phase, stent length in the abdominal cavity was 8.55 ± 2.36 mm and the length of the luminal portion was 50.0 ± 8.36 mm. Stent shortening in the luminal portion was significantly greater in the late phase than in the early phase ( P  = 0.04). Conclusions  CT showed that stent migration can occur even with successful stent deployment, due to various factors such as stent shortening. The antimigratory single flange may be helpful to prevent stent migration, but further prospective comparative studies are needed to confirm our results.

Direct Endoscopic Necrosectomy: Timing and Technique

Walled-off pancreatic necrosis (WOPN) is one of the local complications of acute pancreatitis (AP). Several interventional techniques have been developed over the last few years. The purpose of this narrative review is to explore such methodologies, with specific focus on endoscopic drainage and direct endoscopic necrosectomy (DEN), through evaluation of their indications and timing for intervention. Findings indicated how, after the introduction of lumen-apposing metal stents (LAMS), DEN is becoming the favorite technique to treat WOPN, especially when large solid debris or infection are present. Additionally, DEN is associated with a lower adverse events rate and hospital stay, and with improved clinical outcome.

Current epidemiological trends and in-hospital mortality of acute pancreatitis in Germany: a systematic analysis of standardized hospital discharge data between 2008 and 2017

BACKGROUND

Acute pancreatitis (AP) represents a common gastrointestinal disorder. Complicated disease courses in particular still represent a major clinical challenge and are associated with high mortality. Evaluation of existing data sets and their careful interpretation can support a rational discussion to optimize outcomes of this common gastrointestinal disease.

METHODS

We used standardized hospital discharge data provided by the Federal Statistical Office of Germany to evaluate hospital mortality and current developments of AP in Germany between 2008 and 2017.

RESULTS

In this analysis, 516,618 hospitalized AP cases were included. Main disease etiologies featured biliary (29.9%) and alcoholic (22.7%) AP. The annual frequency of AP increased from 48,858 (2008) to 52,611 (2017), mainly due to a rising incidence of biliary AP. Average hospital mortality was 2.85% and significantly improved over time. While uncomplicated AP had low hospital mortality (1.38%), the presence of organ complications was associated with a mortality of 12.34%. The necessity of mechanical ventilation dramatically increased hospital mortality to 44.06%. Hospital mortality was significantly higher in female patients (3.31%) than males (2.55%) and showed a stepwise increase with patient age. We further identified type 2 diabetes mellitus and obesity as factors associated with increased hospital mortality. Hospital mortality was lowest among patients treated at departments specializing in gastroenterology. Finally, high case volume centers (defined as >98 annual AP cases) had the lowest hospital mortality for patients with complicated courses of AP.

CONCLUSION

With over 50,000 annual hospitalization cases, AP is one of the most important inpatient treatment indications in gastroenterology in Germany. Overall, AP mortality has improved in recent years, presumably due to improved interdisciplinary treatment concepts. In this study, we identified important clinical and epidemiological risk factors for an unfavorable course, which could help to improve risk prediction and triaging, and thus the management of AP.

Predicting the Need for Step-Up Therapy After EUS-Guided Drainage of Pancreatic Fluid Collections With Lumen-Apposing Metal Stents

BACKGROUND & AIMS

A significant proportion of individuals with pancreatic fluid collections (PFCs) require step-up therapy after endoscopic drainage with lumen-apposing metal stents. The aim of this study is to identify factors associated with PFCs that require step-up therapy.

METHODS

A retrospective cohort study of patients undergoing endoscopic ultrasound-guided drainage of PFCs with lumen-apposing metal stents from April 2014 to October 2019 at a single center was performed. Step-up therapy included direct endoscopic necrosectomy, additional drainage site (endoscopic or percutaneous), or surgical intervention after the initial drainage procedure. Multivariable logistic regression was performed using a backward stepwise approach with a P ≤ .2 threshold for variable retention to identify factors predictive for the need for step-up therapy.

RESULTS

One hundred thirty-six patients were included in the final study cohort, of whom 69 (50.7%) required step-up therapy. Independent predictors of step-up therapy included: collection size measuring ≥10 cm (odds ratio [OR], 8.91; 95% confidence interval [CI], 3.36-23.61), paracolic extension of the PFC (OR, 4.04; 95% CI, 1.60-10.23), and ≥30% solid necrosis (OR, 4.24; 95% CI, 1.48-12.16). In a sensitivity analysis of 81 patients with walled-off necrosis, 51 (63.0%) required step-up therapy. Similarly, factors predictive of the need for step-up therapy for walled-off necrosis included: collection size measuring ≥10 cm (OR, 6.94; 95% CI, 1.76-27.45), paracolic extension of the PFC (OR, 3.79; 95% CI, 1.18-12.14), and ≥30% solid necrosis (OR, 7.10; 95% CI, 1.16-43.48).

CONCLUSIONS

Half of all patients with PFCs drained with lumen-apposing metal stents required step-up therapy, most commonly direct endoscopic necrosectomy. Individuals with PFCs ≥10 cm in size, paracolic extension, or ≥30% solid necrosis are more likely to require step-up therapy and should be considered for early endoscopic reintervention.

Interventional endoscopic ultrasound

PURPOSE OF REVIEW

To update on recent advances in interventional endoscopic ultrasound (INVEUS) techniques.

RECENT FINDINGS

The introduction of linear echoendoscopes with larger instrument channels and the combined development of new tools and devices have enabled various new applications of minimally invasive endoscopic ultrasound (EUS)-guided transluminal interventions of the pancreas, biliary system and peri-gastrointestinal structures. In this review, EUS-guided interventions are discussed and evaluated: drainage of peripancreatic fluid collections, access and drainage of bile ducts, gallbladder and pancreatic duct, treatment of gastrointestinal haemorrhage, coeliac plexus block and coeliac plexus neurolysis, fiducial placement, solid and cystic tumour ablation, drug delivery and brachytherapy, gastroenterostomy, angiotherapy and other EUS-guided applications. The EUS-guided interventions are classified based on the available evidence as established or experimental, standardized or nonstandardized procedures in common or rare diseases with well or little known complications and their established or nonestablished treatment.

SUMMARY

Some EUS-guided interventions have sparse published evidence with only single-centre studies, case series or individual case reports, others like drainage of peripancreatic fluid collections have become widely accepted practice. INVEUS has been accepted as an alternative to several surgical approaches, EUS-guided techniques result in faster recovery times, shorter hospital stay and lower costs.

Lumen-apposing metal stents (with videos)

BACKGROUND AND AIMS

Lumen-apposing metal stents (LAMSs) are a novel class of devices that have expanded the spectrum of endoscopic GI interventions. LAMSs with their dumbbell configuration, short saddle length, and large inner luminal diameter provide favorable stent characteristics to facilitate anastomosis formation between the gut lumen and adjacent structures.

METHODS

The MEDLINE database was searched through April 2021 for articles related to LAMSs by using additional relevant keywords such as "walled-off pancreatic necrosis," "pseudocysts," "pancreatic fluid collection," "cholecystitis," "gastroenterostomy," in addition to "endoscopic treatment" and "endoscopic management," among others.

RESULTS

This technology review describes the full spectrum of LAMS designs and delivery systems, techniques for deployment, procedural outcomes, safety, training issues, and financial considerations.

CONCLUSIONS

Although LAMSs were initially introduced for drainage of pancreatic pseudocysts and walled-off necrosis, the versatility of these devices has led to a variety of off-label uses including gallbladder drainage, enteric bypass with the creation of gastroenterostomies, and treatment of luminal GI strictures.

Novel Uses of Lumen-apposing Metal Stents: A Review of the Literature

The field of therapeutic endoscopy has seen many recent advancements. One such emerging field is the use of lumen-apposing metal stents (LAMS). Although a few LAMS have been developed, the most commonly reviewed and the only Food and Drug Administration (FDA)-approved LAMS is the Axios stent by Boston Scientific. In 2013, LAMS were initially approved by the FDA for the management of pancreatic fluid collection drainage in the presence walled-off necrosis. Pancreatic fluid collections are traditionally drained with either a plastic stent or a covered biliary self-expanding metal stent. Plastic stents have a double pigtail feature which prevents stent migration. However, their narrow lumen poses limitations as it can lead to early stent occlusion. Fully covered metal stents have larger diameters, allowing improved drainage and decreased stent occlusion but their tubular shape is prone to migration. Consequently, this results in leakage, and frequent retrievals. Over the years, due to their versatility, LAMS now have many off label uses. This includes management of gastric outlet obstruction, superior mesenteric artery syndrome, strictures, gallbladder drainage, and postsurgical collection drainage. In this review, we will be discussing the FDA approved and the nonapproved uses of LAMS.

Safety issues in endoscopy ultrasound-guided interventions using lumen apposing metal stents: a review of the literature

Lumen-apposing metal stents (LAMS) are recently introduced devices that allow to create anastomoses. The indications for LAMS placement are increasing and currently these stents can be used in multiple clinical situations such as endoscopic drainage of pancreatic fluid collections (PFCs), endoscopic ultrasound-guided choledocho-duodenostomy (EUS-CDS), endoscopic ultrasound gallbladder drainage (EUS-GBD), endoscopic ultrasound gastrojejunostomy (EUS-GJ). Since their introduction, they have revealed to allow a higher rate of technical and clinical success, and potentially lower risk of adverse events (AEs) compared with previously available devices. Despite ongoing innovation, any advanced intervention carries risks of AEs. These AEs may occur during the deployment or can be delayed because of the consequent effects of the procedure and/or stent itself. This review represents an overview of current indications, technical and clinical results, with an extensive focus on safety issues related to placement and on long-term indwelling related ones.