Lumen apposing metal stents for pancreatic fluid collections: Recognition and management of complications

Effect of proton pump inhibitors on occlusion of lumen-apposing metal stents and rate of endoscopic necrosectomies: a Europe-wide multicenter cohort study

BACKGROUND

 Lumen-apposing metal stents (LAMS) are widely used to drain walled-off necrosis (WON). LAMS occlusion is a significant clinical problem and identification of risk factors for LAMS occlusion could contribute to novel preventive strategies. A previous study suggested contradictory effects of proton pump inhibitors (PPIs) on occlusion and necrosectomy rates.

METHODS

 We conducted a Europe-wide multicenter retrospective cohort study assessing WONs drained by LAMS. The primary aims were to assess the strength of association between PPI intake and LAMS occlusion and necrosectomy rates, respectively. The secondary aim was to assess the strength of association between PPI intake and other LAMS-associated complications. Multiple mixed-effects models were used to control for possible confounding covariates.

RESULTS

 893 patients with 967 LAMS from 17 centers were included. After excluding incomplete datasets and patients who took PPIs intermittently, 768 LAMS remained. The overall occlusion rate was 28.0 %. Most occlusions occurred within 10 days. Most patients received PPIs continuously (n = 577 vs. no intake n = 191). In patients who did not use PPIs continuously, lower rates of LAMS occlusion (odds ratio [OR] 0.61, P = 0.04) and necrosectomies (incidence rate ratio 0.8, P = 0.006) were observed. A post hoc analysis exhibited a dose- and compound-dependent effect of PPI intake on necrosectomy rate. No increase in other complications in the non-PPI group, such as bleeding events (OR 1.14) were observed.

CONCLUSION

 PPI intake was associated with higher rates of LAMS occlusion and necrosectomy.

Outcomes and Post-removal Course of Lumen-Apposing Metal Stent Placement for Peripancreatic Fluid Collections: A Comparative Study of Pancreatic Pseudocysts and Walled-Off Necrosis

AIM

Pancreatic fluid collections (PFCs) are common local complications of pancreatitis that may require interventional therapy. Endoscopic ultrasound (EUS)-guided transluminal drainage from the digestive tract, particularly with lumen-apposing metal stents (LAMS), is the first-line therapy due to its safety and efficacy. However, adverse events and post-removal courses remain uncertain. This study aimed to clarify the characteristics of LAMS placement and its removal, comparing pancreatic pseudocysts (PPC) and walled-off necrosis (WON).

METHODS

This single-center retrospective study included 23 patients who underwent transgastric LAMS placement for PFCs under EUS guidance. The patients were categorized into the PPC group (n = 14) and the WON group (n = 9). Backgrounds and clinical outcomes were analyzed and compared.

RESULTS

The mean procedure time was 19 minutes in the PPC group and 25 minutes in the WON group, with no significant difference (p = 0.11). The overall incidence of adverse events during LAMS placement was 14.3% in the PPC group and 33.3% in the WON group, with no significant difference (p = 0.28), but the incidence of infection of noninfected fluid collections was 0% in the PPC group and 55.5% in the WON group, significantly higher in the WON group (p = 0.0016). At the time of LAMS removal, a double-pigtail plastic stent (DPS) was replaced in 53.8% of the PPC group and 57.1% of the WON group. Within one year, 57.1% of the replaced DPS in the PPC group and 25.0% in the WON group became dislocated. There were no adverse events due to the dislocation of the replaced DPS. Adverse events occurred in one patient in each group after LAMS removal: 7.7% in the PPC group and 14.3% in the WON group (p = 0.64), which consisted of peritonitis in the PPC group and recurrent infection of fluid collection in the WON group, and both of these events occurred when the replaced DPS was still in place after LAMS removal.

CONCLUSIONS

Although there was no significant difference in the overall incidence of adverse events between PPC and WON, the incidence of infection after LAMS placement was significantly higher in WON. Regarding the replaced DPS, there were some cases of dislocation within one year, but there were no related adverse events. Adverse events occurred even after the removal of LAMS and replacement with DPS, so careful follow-up is required.

Prophylactic splenic artery embolization using n-butyl-2-cyanoacrylate and coils prior to endoscopic necrosectomy in a patient with necrotizing pancreatitis: A case report

We present a case of prophylactic endovascular embolization in a 51-year-old man with necrotizing pancreatitis (NP) before undergoing endoscopic necrosectomy (EN). Contrast-enhanced CT imaging revealed the presence of a walled-off necrosis (WON) surrounding the pancreas, with the splenic artery coursing through the cavity. The splenic artery was embolized using n-butyl-2-cyanoacrylate (NBCA) and coils to mitigate the risk of massive bleeding in EN. A newly developed polytetrafluoroethylene (PTFE)-coated microcatheter was used to inject NBCA, enabling embolization of a long segment of the splenic artery without adhering to the vessel wall. Coils were placed distal and proximal to the embolized segment to optimize control. Over 5 sessions of EN, no massive bleeding was encountered. This report demonstrates the benefits of utilizing PTFE-coated microcatheters for enhanced safety and maneuverability during embolization with NBCA. Furthermore, it highlights the importance of prophylactic embolization during EN for managing NP.

Complications and management of interventional endoscopic ultrasound: A critical review

In the last decades, Endoscopic ultrasound (EUS) has rapidly grown and evolved from being mainly a diagnostic procedure, to being an interventional and therapeutic tool in several pathological clinical scenarios. With the progressive growth in technical expertise and dedicated devices, interventional endoscopic ultrasound procedures (IEUSP) have shown high rates of technical and clinical success, together with a relatively safe profile. However, the description and the standardization of different and specific types of adverse events (AEs) are still scarce in literature, and, consequently, even less the management of AEs. The aim of this study is to critical review and to describe AEs related to each of the main IEUSP, and to provide an overview on the possible management strategies of endoscopic complications. Future studies and guidelines are surely required to reach a better standardization of different AEs and their best management.

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.

Migrated lumen-apposing stent trapped within a pancreatic fluid collection: Forward-view EUS for the rescue!

Video 1Migrated lumen-apposing stent trapped within a pancreatic fluid collection: forward-view EUS for the rescue!

The Usefulness and Reliability of Coagrasper for Artery Bleeding during Endoscopic Necrosectomy

Although endoscopic necrosectomy (EN) is a less invasive therapy for walled-off necrosis (WON), arterial bleeding can occur during EN. A 60-year-old man with infected WON underwent the EN procedure. During EN, the artery in the WON cavity was injured. As the artery was directly visible, we grasped it using a Coagrasper and coagulated the bleeding point. However, the bleeding was aggravated after coagulation owing to an extension of the vessel damage. The entire vessel was grasped, and complete hemostasis was achieved. The Coagrasper is useful for managing arterial bleeding; however, it should be employed only on the basis of its characteristics and in suitable scenarios.

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.

The severity and infection of acute pancreatitis may increase the risk of bleeding in patients undergoing EUS-guided drainage and endoscopic necrosectomy: a large retrospective cohort

BACKGROUND

There has been great progress in the use of endoscopic ultrasound (EUS)-guided drainage in acute pancreatitis patients using a novel lumen-apposing metal stent (LAMS) in the last decade, but some patients experience bleeding. Our research analyzed the preprocedural risk factors for bleeding.

METHODS

From July 13, 2016 to June 23, 2021, we retrospectively analyzed all patients who received endoscopic drainage by the LAMS in our hospital. Univariate and multivariate statistical analyses were used to identify the independent risk factors. We plotted ROC curves based on the independent risk factors.

RESULTS

A total of 205 patients were analyzed and 5 patients were excluded. A total of 200 patients were included in our research. Thirty (15%) patients presented with bleeding. In the multivariate analysis, computed tomography severity index score (CTSI) score [odds ratio (OR), 2.66; 95% CI: 1.31-5.38; P = 0.007], positive blood cultures [odds ratio (OR), 5.35; 95% CI: 1.31-21.9; P = 0.02], and Acute Physiology and Chronic Health Evaluation II (APACHE II) score [odds ratio (OR), 1.14; 95% CI: 1. 01-1.29; P = 0.045] were associated with bleeding. The area under the ROC curve of the combined predictive indicator was 0.79.

CONCLUSION

Bleeding in endoscopic drainage by the LAMS is significantly associated with the CTSI score, positive blood cultures, and APACHE II score. This result could help clinicians make more appropriate choices.

Lumen-Apposing Metal Stent With and Without Concurrent Double-Pigtail Plastic Stent for Pancreatic Fluid Collections: A Comparative Systematic Review and Meta-Analysis

Background

Lumen-apposing metal stents (LAMSs) are often used to drain pancreatic fluid collections (PFCs). However, adverse events, such as stent obstruction, infection, or bleeding, have been reported. Concurrent double-pigtail plastic stent (DPPS) deployment has been suggested to prevent these adverse events. This meta-analysis aimed to compare the clinical outcomes of LAMS with DPPS vs. LAMS alone in the drainage of PFCs.

Methods

An extensive search was conducted in the literature to include all the eligible studies that compared LAMS with DPPS vs. LAMS alone for drainage of PFCs. Pooled risk ratios (RRs) with the 95% confidence intervals (CIs) were obtained within a random-effect model. The outcomes were technical and clinical success, and overall adverse events, including stent migration and occlusion, bleeding, infection, and perforation.

Results

Five studies involving 281 patients with PFCs (137 received LAMS plus DPPS vs. 144 received LAMS alone) were included. LAMS plus DPPS group was associated with comparable technical success (RR: 1.01, 95% CI: 0.97 - 1.04, P = 0.70) and clinical success (RR: 1.01, 95% CI: 0.88 - 1.17). Lower trends of overall adverse events (RR: 0.64, 95% CI: 0.32 - 1.29), stent occlusion (RR: 0.63, 95% CI: 0.27 - 1.49), infection (RR: 0.50, 95% CI: 0.15 - 1.64), and perforation (RR: 0.42, 95% CI: 0.06 - 2.78) were observed in LAMS with DPPS group compared to LAMS alone but without a statistical significance. Stent migration (RR: 1.29, 95% CI: 0.50 - 3.34) and bleeding (RR: 0.65, 95% CI: 0.25 - 1.72) were similar between the two groups.

Conclusions

Deployment of DPPS across LAMS for drainage of PFCs has no significant impact on efficacy or safety outcomes. Randomized, controlled trials are necessary to confirm our study results, especially in walled-off pancreatic necrosis.

Endoscopic Ultrasound Guided Biliary Drainage in Malignant Distal Biliary Obstruction

Malignant biliary obstruction (MBO) is a challenging medical problem that often negatively impacts the patient's quality of life (QoL), postoperative complications, and survival rates. Endoscopic approaches to biliary drainage are generally performed by ERCP or, in selected cases, with a percutaneous transhepatic biliary drainage (PTBD). Recent advances in therapeutic endoscopic ultrasound (EUS) allow drainage where previous methods have failed. EUS has evolved from a purely diagnostic technique to one that allows a therapeutic approach in the event of ERCP failure in distal MBO. Moreover, the introduction of dedicated accessories and prostheses for EUS-guided transmural biliary drainage (EUS-BD) made these procedures more successful with regard to technical success, clinical outcomes and reduction of adverse events (AEs). Finally, lumen-apposing metal stents (LAMS) have improved the therapeutic role of the EUS. Subsequently, the electrocautery enhanced tip of the LAMS (EC-LAMS) allows a direct access of the delivery system to the target lumen, thereby simplifying and reducing the EUS-BD procedure time. EUS-BD using LAMS and EC-LAMS has proven effective and safe with a low rate of AEs. This review aims to evaluate biliary drainage techniques in malignant obstruction, focusing on the role of EUS biliary drainage by LAMS.

Current uses of electro-cautery lumen apposing metal stents in endoscopic ultrasound guided interventions

The electro-cautery lumen apposing metal stent (EC-LAMS) is a newly developed device that integrates the electro-cautery cyctotome with the one-step metal stent delivery and releasing system in recent years. LAMS was first designed to complete the drainage of pancreatic fluid collection under endoscopic ultrasound guidance, and the technological innovation of EC-LAMS has made more off-labeled indications of endoscopic intervention for gastrointestinal diseases realized, such as abdominal fluid drainage, bile duct, or gallbladder drainage through stomach or duodenum, gastrointestinal anastomosis, and the establishment of fistulous channel for further endoscopic operation when necessary. The unique feature of this metal stent is that it has the design of a saddle shape and a large lumen, and can almost connect the adjacent structures to minimize the risk of perforation and leakage. Compared with traditional LAMS, EC-LAMS, an advanced integrated device, can greatly simplify the endoscopic process, shorten the procedure time and reduce the technical difficulty, thus it can help endoscopists complete more complex endoscopic interventions. In this review, we discuss the state of art with regard to EC-LAMS and its endoscopic process, current indications, outcomes, adverse events, and future application prospects.

Prediction and management of bleeding during endoscopic necrosectomy for pancreatic walled-off necrosis: results of a large retrospective cohort at a tertiary referral center

BACKGROUND AND AIMS

Lumen-apposing metal stents (LAMSs) provide an endoscopic method for management of walled-off necrosis (WON) and a gateway for the performance of endoscopic necrosectomy (EN). However, bleeding may occur in up to 20% of EN procedures. Predictive factors for bleeding in this patient population are unknown, and there is no agreed-on algorithm for the management of bleeding. The aim of this study was to evaluate preprocedural risk factors for bleeding in patients undergoing endoscopic drainage or EN for WON.

METHODS

A retrospective cohort of patients undergoing EN for WON was reviewed. Demographics, comorbidities, concurrent medications, and etiology of pancreatitis were recorded. Pre-, peri-, and postprocedural clinical variables were compared using the χ² test and independent t test.

RESULTS

Between June 2014 and October 2020, 536 ENs were performed in 151 patients. Intraprocedural bleeding occurred during 28 procedures (5.2%) in 18 patients (11.9%). Endoscopic hemostasis was attempted in 8 patients (10 procedures). Eight patients (10 procedures) in total were treated by interventional radiology (IR). Thrombocytopenia (P = .006) and cirrhosis (P = .049) were associated with intraprocedural bleeding, although thrombocytopenia was present in only 1 patient. Identification of a vessel within the cavity endoscopically was also associated with bleeding (P < .001). On multivariate analysis, identification of a vessel within the cavity endoscopically remained a strong predictor of bleeding (P < .001), whereas cirrhosis was no longer significant. Patients who required IR for hemostasis were transfused with significantly more blood before the procedure than patients who did not (3.4 units vs .67 units, P = .002).

CONCLUSIONS

EN for WON was associated with a 5.2% per-procedure risk of bleeding and an 11.9% per-patient bleeding risk. Identification of a vessel within the cavity during endoscopy is predictive of bleeding during EN. Patients who require more transfusions before endoscopy may require earlier intervention by IR.

Clinical Practice Guidelines for the Endoscopic Management of Peripancreatic Fluid Collections

Endoscopic ultrasonography-guided intervention has gradually become a standard treatment for peripancreatic fluid collections (PFCs). However, it is difficult to popularize the procedure in Korea because of restrictions on insurance claims regarding the use of endoscopic accessories, as well as the lack of standardized Korean clinical practice guidelines. The Korean Society of Gastrointestinal Endoscopy appointed a Task Force to develop medical guidelines by referring to the manual for clinical practice guidelines development prepared by the National Evidence-Based Healthcare Collaborating Agency. Previous studies on PFCs were searched, and certain studies were selected with the help of experts. Then, a set of key questions was selected, and treatment guidelines were systematically reviewed. Answers to these questions and recommendations were selected via peer review. This guideline discusses endoscopic management of PFCs and makes recommendations on Indications for the procedure, pre-procedural preparations, optimal approach for drainage, procedural considerations (e.g., types of stent, advantages and disadvantages of plastic and metal stents, and accessories), adverse events of endoscopic intervention, and procedural quality issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This will be revised as necessary to address advances and changes in technology and evidence obtained in clinical practice and future studies.

Clinical Practice Guidelines for the Endoscopic Management of Peripancreatic Fluid Collections

Endoscopic ultrasonography-guided intervention has gradually become a standard treatment for peripancreatic fluid collections (PFCs). However, it is difficult to popularize the procedure in Korea because of restrictions on insurance claims regarding the use of endoscopic accessories, as well as the lack of standardized Korean clinical practice guidelines. The Korean Society of Gastrointestinal Endoscopy appointed a Task Force to develop medical guidelines by referring to the manual for clinical practice guidelines development prepared by the National Evidence-Based Healthcare Collaborating Agency. Previous studies on PFCs were searched, and certain studies were selected with the help of experts. Then, a set of key questions was selected, and treatment guidelines were systematically reviewed. Answers to these questions and recommendations were selected via peer review. This guideline discusses endoscopic management of PFCs and makes recommendations on Indications for the procedure, pre-procedural preparations, optimal approach for drainage, procedural considerations (e.g., types of stent, advantages and disadvantages of plastic and metal stents, and accessories), adverse events of endoscopic intervention, and procedural quality issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This will be revised as necessary to address advances and changes in technology and evidence obtained in clinical practice and future studies.

The Off-Label Use of a Lumen-Apposing Metal Stent (LAMS) for a Benign Colon Anastomotic Stricture Causing Recurrent Bowel Obstruction in a Patient with Keloids

Anastomotic strictures are a known complication of colorectal surgery. Despite a wide range of medical devices that have been deployed for this complication, outcomes remain challenging. Lumen-apposing metal stents (LAMSs) have recently emerged as a potentially superior therapeutic option. We herein report a patient with a past medical history of pT3, N0 adenocarcinoma of the colon with anastomotic stricture recurrence who underwent successful placement of an LAMS. We suggest that patients with a predisposition for keloid formation or fibrosis-prone anastomotic wound healing should be considered for LAMS deployment early in the treatment course.

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

Background and study aims  Lumen-apposing metal stents (LAMS) are increasingly used for drainage of walled-off pancreatic necrosis (WON). Recent studies suggested greater adverse event (AE) rates with LAMS for WON. We conducted a systematic review and meta-analysis to compare the safety and efficacy of LAMS with double-pigtail plastic stents (DPPS) for endoscopic drainage of WON. The primary aim was to evaluate stent-related AEs. Methods  In October 2019, we searched the Ovid (Embase, MEDLINE, Cochrane) and Scopus databases for studies assessing a specific LAMS or DPPS for WON drainage conducted under EUS guidance. Safety outcomes were AE rates of bleeding, stent migration, perforation, and stent occlusion. Efficacy outcomes were WON resolution and number of procedures needed to achieve resolution. A subanalysis including non-EUS-guided cases was performed. Results  Thirty studies including one randomized controlled trial (total 1,524 patients) were analyzed. LAMS were associated with similar bleeding (2.5 % vs. 4.6 %, P =  0.39) and perforation risk (0.5 % vs. 1.1 %, P =  0.35) compared to DPPS. WON resolution (87.4 % vs. 87.5 %, P =  0.99), number of procedures to achieve resolution (2.09 vs. 1.88, P =  0.72), stent migration (5.9 % vs. 6.8 %, P =  0.79), and stent occlusion (3.8 % vs. 5.2 %, P =  0.78) were similar for both groups. Inclusion of non-EUS-guided cases led to significantly higher DPPS bleeding and perforation rates. Conclusions  LAMS and DPPS were associated with similar rates of AEs and WON resolution when limiting analysis to EUS-guided cases. Higher bleeding rates were seen in historical studies of DPPS without EUS guidance. Additional high-quality studies of WON treatment using consistent outcome definitions are needed.

Pancreatic fluid collections: Clinical manifestations, diagnostic evaluation and management

Pancreatic fluid collections (PFC), including pancreatic pseudocysts and walled-off pancreatic necrosis, are a known complication of severe acute pancreatitis. A majority of the PFCs remain asymptomatic and resolve spontaneously. However, some PFCs persist and can become symptomatic. Persistent PFCs can also cause further complications such as the gastric outlet, intestinal, or biliary obstruction and infection. Surgical interventions are indicated for the drainage of symptomatic sterile and infected PFCs. Management of PFCs has evolved from a primarily surgical or percutaneous approach to a less invasive endoscopic approach. Endoscopic interventions are associated with improved outcomes with lesser chances of complications, faster recovery time, and lower healthcare utilization. Endoscopic ultrasound-guided drainage of PFCs using lumen-apposing metal stents has become the preferred approach for the management of symptomatic and complicated PFCs.

Massive Upper Gastrointestinal Bleeding Following LAMS (Lumen-Apposing Metal Stent) Placement

Pancreatic pseudocyst is a common complication of pancreatitis. Pseudocysts may require decompression when they become painful, infected, or start compressing surrounding organs. Decompression is achieved by endoscopic cystogastrostomy. Recently, the use of lumen-apposing metal stent (LAMS) for cystogastrostomy has gained popularity due to ease of use and high technical success. LAMS has a wider lumen, which allows for direct endoscopic necrosectomy in the cases of walled-off necrosis. Our patient is a 30-year-old male who presented with massive hematemesis and dizziness. He had a history of chronic alcohol-induced pancreatitis. Three weeks before the presentation, he underwent a cystogastrostomy with LAMS placement to treat a 10-cm walled-off necrosis. Urgent computed tomography (CT) scan did not reveal any acute finding suggestive of bleeding. Esophagogastroduodenoscopy showed blood protruding from the LAMS with a large clot formation. Attempts to stop bleeding were unsuccessful. He underwent CT angiography of the abdomen. CT angiography showed a bleeding pseudoaneurysm (PA) believed to be a complication of the LAMS. Subsequently, multiple coils were placed in the splenic artery near the PA. The patient continued to improve without a further drop in hemoglobin and was eventually discharged. PA formation and subsequent rupture is a rare delayed complication of LAMS. It may lead to massive gastrointestinal bleeding with a high mortality rate. Diagnostic delays have resulted in increased mortality by 60%. In this article, we present a case of massive gastrointestinal bleeding due to a ruptured splenic artery PA presenting as a delayed complication of LAMS.

Peripancreatic fluid collections, plastic stents, and different sub-types of metal stents: Where does the evidence land?

BACKGROUND

Peripancreatic fluid collections (PFCs) are a frequent complication of acute pancreatitis. Symptomatic PFCs may need to be drained, and there are multiple endoscopic accessories that can facilitate the procedure. This paper aims to compare the success rate, number of procedures required for resolution and adverse events rate for PFCs EUS-guided drainage with plastic stents and lumen-apposing metal stents (LAMS).

METHODS

This is a retrospective analysis of a consecutive sample of patients that was collected from 2013 - 2019. The medical records of these patients were reviewed, and the outcomes for each type of stent (plastic vs LAMS, and different subtypes of LAMS) were compared in terms of clinical success, number of re-interventions needed, and adverse events.

RESULTS

A total of 33 patients (23 males) were treated for PFCs with EUS-guided drainage and stenting. The patients' ages ranged between 14 and 85 years (mean ± SD: 43.5 ± 19 years). Overall, there was no difference between plastic stents and LAMS in terms of symptomatic recovery (P = 0. 24), but metal stents had better results with regards to radiological resolution (P = 0.03), and were associated with a higher number of necrosectomies (P = 0.029). Adverse events occurred more frequently in patients who had plastic stents, but direct comparison between the two groups showed that the difference was not statistically significant (P = 0.2). Stratification for different LAMS subtypes showed no difference in terms of symptomatic or radiological resolution (P =0.49), number of rescue procedures (P = 0.41), and adverse events (P = 0.81).

CONCLUSION

Our study, along with the current available evidence, suggests a slight advantage of metal stents over plastic stents in terms of clinical success, need for rescue procedures, and incidence of adverse events. Furthermore, it provides empirical evidence that the different sub-types of LAMS perform similarly when compared against each other.

Endoscopic Ultrasound-Guided Drainage of Intramural Duodenal Abscess Caused by Foreign Body Ingestion

A 63-year-old man presented with fever and generalized weakness for 2 days. Computed tomography scan showed an intramural duodenal abscess and a linear radiolucent foreign body penetrating the duodenal wall. Endoscopic drainage was performed. Endoscopic ultrasound showed fluid collection in the second portion of the duodenum. The duodenal lumen was punctured with the creation of stoma using a lumen-apposing metal stent and electrocautery system. The stent was deployed, and the drainage of purulent fluid followed. The foreign body was suspected to be a wire brush bristle. The patient received intravenous antibiotics for 14 days. Follow-up images showed the resolution of the abscess.

The augmented role of pancreatic imaging in the era of endoscopic necrosectomy: an illustrative and pictorial review

Endoscopic cystogastrostomy for mature pancreatic collections has long been recognized. However, FDA approval of newer lumen-apposing metallic stents in 2014 has now brought pancreatic necrosectomy to the endoscopic realm. Endoscopic drainage of Walled-off necrosis and direct endoscopic necrosectomy are technically challenging procedures with higher rates of complications. Collaborative clinical decision making both pre- and post-procedurally between the radiologist, endoscopist, and the surgeon can greatly improve outcomes in necrotizing pancreatitis. Herein, we review the basic pathophysiology that underlies progressive radiographic findings in NP, value of preprocedural imaging, current management algorithms, newer tools, and techniques as well as potential post-procedure complications on imaging follow-up after endoscopic interventions in necrotizing pancreatitis.

Lumen-Apposing Metal Stent Used to Treat Malignant Esophageal Stricture

Malignant esophageal strictures often require stent placement to alleviate dysphagia and improve quality of life. We present a novel application of a lumen-apposing metal stent to bypass a malignant esophageal stricture in the setting of altered gastric anatomy.

Recent advances in treatment of pancreatic pseudocyst with endoscopic ultrasonography guided lumen-apposing metal stents

Endoscopic pancreatic pseudocyst (PPC) drainage has become one of the most important methods for the treatment of PPC. With the continuous application of the new lumen-apposing metal stent (LAMS), it has shown better efficacy and clinical practical value. This paper focuses on the current situation of endoscopic PPC drainage, especially the therapeutic effect, complications, and countermeasures with endoscopic ultrasound-guided LAMS.

A Remnant Choledochal Cyst after Choledochal Cyst Excision Treated with a Lumen-Apposing Metal Stent: A Case Report

A lumen-apposing metal stent (LAMS) is a saddle-shaped stent with large flanges at both ends, thereby preventing stent migration and helping with approximation of the adjacent structures. We report the case of a 25-year-old female with remnant choledochal cyst which was successfully treated with LAMS after initial treatment failure with a plastic stent. Although complete excision of the cyst is the definite treatment of choledochal cysts, endoscopic ultrasonography-guided cystoduodenostomy can be considered in cases wherein surgery is not feasible and dysplasia is not present. LAMS may be preferred to plastic stents for effective resolution of remnant choledochal cyst and prevention of ascending infection.

EUS-guided stent removal in buried lumen-apposing metal stent syndrome: a case series

BACKGROUND AND AIMS

Lumen-apposing metal stents (LAMSs) play an increasing role in transgastric and transduodenal drainage of pancreatic fluid collections and allow novel EUS-guided interventions. Alongside the main adverse events of bleeding and occlusion, LAMSs can be overgrown by mucosa, which leads to the inability to visualize the stent in endoscopy.

METHODS

We describe a series of 4 cases of buried LAMSs that were removed under EUS guidance for identification of the stent followed by removal with rat-tooth forceps.

RESULTS

The median in situ time of the LAMSs in the reported 4 cases was 53 days. All stents could no longer be visualized endoscopically when drainage of necrosis was complete. All 4 buried LAMSs could be identified by EUS and were removed successfully with forceps. In 1 case, balloon dilation of the stent tract was performed before stent removal. No adverse events were observed after the procedure.

CONCLUSIONS

Buried stent syndrome is a rare adverse event of LAMSs. Here we describe a safe and effective approach for stent identification and removal without prior mucosal dissection.

Lumen-apposing metal stents in interventional endoscopy: a state-of-the-art review with focus on technical and clinical successes and complications

Endoscopic transmural drainage is considered the initial treatment option for pancreatic fluid collections. Recently, lumen-apposing metal stents have been introduced for pancreatic fluid collections drainage under endoscopic ultrasound guidance, in addition to evolving data in bile duct and gallbladder drainage. We aimed to perform systematic review with reporting pooled data analysis on technical success, clinical success and complications rate of endoscopic ultrasound-guided lumen-apposing metal stents uses. A MEDLINE/PubMed and EMBASE search for all studies on lumen-apposing metal stents uses in pancreatic, biliary and other indications was conducted. Data regarding safety, complications and yield were extracted and included in the final pooled analysis. Overall, 19 articles dealing with pancreatic fluid collections drainage, 18 articles reporting on bile duct drainage and 19 articles relevant to gallbladder drainage were identified. Technical and clinical successes in all disease conditions were high and reached more than 95%. Complications rate in pancreatic fluid collections, bile duct and gallbladder drainages were 12%, 11.2% and 9.8%, respectively. Endoscopic ultrasound-guided lumen-apposing metal stents is technically feasible with very high success rate and acceptable complications rate.

Imaging of Lumen-Apposing Metal Stents in Abdominopelvic Applications

OBJECTIVE. Lumen-apposing metal stents (LAMS) are increasingly being used for abdominopelvic drainage applications. The purpose of this article is to describe the normal imaging appearance of these stents and the radiologic findings in stent-related complications. CONCLUSION. LAMS facilitate effective drainage, but the complications include bleeding, pseudoaneurysm formation, stent occlusion, and stent migration.

A retrospective, multicenter analysis of incidents associated with Axios™ lumen-apposing stents

INTRODUCTION

there is controversy with regard to the risks associated with lumen-apposing metal stents (LAMSs), with significant variations between available reports.

OBJECTIVES

to describe the types and proportions of complications that arise during the permanence time and removal of Axios™ LAMS. Furthermore, the relationship between patency time, therapeutic target and the presence of complications was also described.

METHODS

a retrospective, multicenter case series study was performed of all patients with an implanted LAMS to access extra-luminal structures during 2017. Only technically successful cases were recorded.

RESULTS

a total of 179 patients from seven sites (range, 4-68 cases/site) were included in the study, with a mean age of 64.3 years (SD: 15.8; range: 24.6-98.8 years) and 122 (68.2%) were male. Most common indications included encapsulated necrosis (58, 32.4%), pseudocysts (31, 17.3%) and gallbladder drains (26, 14.5%). Complications during LAMS stay were reported in 19 patients (10.9%); stent lumen or gastroduodenal obstruction (8, 4.5%) and bleeding (7, 3.9%) were the most common. LAMS were not removed in 86 (48%) patients due to the following reasons: a permanent stent was used (46, 53.5%), loss to follow-up (18, 20.9%), patient demise (16, 18.6%) and stent migration (6, 7%). Five (5.4%) complications were reported during stent removal, which were three bleeds and two perforations. No association was found between stent duration and complications (p = 0.67).

CONCLUSION

complications secondary to LAMS insertion are uncommon but may be serious. This study found no association between complications and stent duration.

Endoscopic ultrasound-guided treatment of pancreatic fluid collections with lumen apposing metallic stents: lessons learned

Pancreatic fluid collections are common pancreatitis complications that frequently require drainage. Endoscopic ultrasound-guided placement of expandable lumen apposing metallic stents has recently emerged as an effective and less invasive treatment option. It is associated with less morbidity, lower costs, and faster clinical recovery than other therapeutic modalities. Nevertheless, this procedure may result in severe complications such as bleeding, buried stent syndrome, and prosthesis dislodgement (with perforation and peritoneal leakage). We performed 108 EUS-guided drainages with lumen apposing metallic stents for the treatment of pancreatic fluid collections with 8 complications and only two cases that required urgent surgical procedures resulting in one fatality. We present this two severe complications submitted to surgical treatment and discuss potential signs of alarm that must be taken under consideration before choosing a treatment modality.

Endoscopic Drainage of Pancreatic Fluid Collections

Endoscopy has emerged as a mainstay in the management of pancreatic fluid collections (PFCs), representing an important advance in clinical medicine that has significantly improved the risk-benefit ratio of treating this complex patient population. While endoscopic pseudocyst drainage has generally supplanted surgical and percutaneous approaches, the optimal strategy for walled-off necrosis remains variable and multi-disciplinary despite an emerging trend from randomized trials favoring endoscopy. Although several issues pertaining to endoscopic drainage appear to have been settled - such as the use of endoscopic ultrasound - other pressing questions - including the optimal prosthesis and debridement strategy - remain unanswered, and rigorous investigation is needed. This review aims to provide an evidence-based but practical appraisal of the endoscopic drainage of PFCs through the perspective of the author, with an emphasis on relevant clinical and endoscopic considerations and important research questions.

Endoscopic Interventions in Acute Pancreatitis: What the Advanced Endoscopist Wants to Know

Endoscopic interventions play an important role in the modern management of pancreatic fluid collections. Successful management of pancreatitis is dependent on proper classification of the disease and its local complications. The 2012 revised Atlanta classification divides acute pancreatitis into subtypes of necrotizing pancreatitis and interstitial edematous pancreatitis (IEP) on the basis of the radiologic presence or absence of necrosis, respectively. Local complications of IEP include acute pancreatic fluid collections and pseudocysts, which contain fluid only and are differentiated by the time elapsed since the onset of symptoms. Local complications of necrotizing pancreatitis include acute necrotic collections and walled-off necrosis, which contain nonliquefied necrotic debris and are differentiated by the time elapsed since the onset of symptoms. Endoscopic techniques are used to treat local complications of pancreatitis, often in a step-up approach, by which less invasive techniques are preferred initially with potential subsequent use of more invasive procedures, dependent on the patient's clinical response and collection evolution. Common interventions performed by the advanced endoscopist include endoscopic transmural drainage and endoscopic transmural necrosectomy. However, some collections require a multimodal approach with adjunctive placement of percutaneous drainage catheters or the use of videoscopic-assisted retroperitoneal débridement. Additional endoscopic interventions may be required in the setting of pancreatic or biliary duct stones or strictures. Common complications of endoscopic intervention in the setting of pancreatitis include bleeding, infection, perforation, and stent migration. This article reviews the classification of acute pancreatitis, familiarizes radiologists with the common endoscopic techniques used in its management, and improves identification of the clinically relevant imaging findings and procedural complications related to endoscopic interventions in pancreatitis. ^©RSNA, 2018.

Comparing efficacy of lumen-apposing stents to plastic stents in the endoscopic management of mature peripancreatic fluid collections: a single-center experience

Introduction

Mature peripancreatic fluid collection (MPFC) is a known and often challenging consequence of acute pancreatitis and often requires intervention. The most common method accepted is the “step-up approach,” which consists of percutaneous drainage followed, if necessary, by minimally invasive retroperitoneal necrosectomy. Our paper aims to distinguish between plastic stents and lumen-apposing stents in the endoscopic management of MPFC in terms of morbidity, mortality, and haste of fluid collection resolution.

Methods

A retrospective analysis was performed at UMass Memorial Medical Center in patients with a diagnosis of MPFC. Utilizing medical records, clinical data, radiology, as well as endoscopic evidence, patients were differentiated by stent type used (plastic versus lumen-apposing) for the management of the MPFC. The primary outcome of the study was to assess the time to MPFC resolution following the placement of either plastic or lumen-apposing stents (on endoscopic ultrasound or computerized tomography scan) using a multivariate analysis with a logistic regression model.

Results

A total of 54 patients were included in this study from UMass Memorial Medical Center between 2012 and 2015. Twelve (22%) of these patients received lumen-apposing stents and 42 (78%) of these patients received plastic pigtail stents. For the lumen-apposing stent group, the mean interval between stent placement and resolution of MPFC was 57 days as compared to 102 days for plastic pigtail stents (p=0.02). The mean interval for placement/removal of lumen-apposing stents was 48 days as compared to 81 days for plastic pigtail stents (p=0.01). Stent migration was seen in 5 patients (11%) who received a plastic pigtail stent compared to 0 (0%) patients who received a lumen-apposing stent.

Discussion

Our study demonstrates that lumen-apposing stents result in a significant reduction in the interval between stent placement and MPFC resolution as well as the time from stent placement to removal, when compared to plastic pigtail stents, the prior standard-of-care. Our study reached similar conclusions regarding the number of stents placed. However, we did not find a significant difference between the complication rates, specifically peri- and postprocedural bleeding or perforation, between the 2 study groups, as demonstrated in prior papers.

Isolated pancreatic tail remnants after transgastric necrosectomy can be observed

BACKGROUND

Severe necrotizing pancreatitis may result in midbody necrosis and ductal disruption leaving an isolated pancreatic tail. The purpose of this study was to characterize outcomes among patients with an isolated tail remnant who underwent transgastric drainage or necrosectomy (endoscopic or surgical) and determine the need for subsequent operative management.

MATERIALS AND METHODS

Patients with necrotizing pancreatitis and retrogastric walled-off collections treated by surgical transgastric necrosectomy or endoscopic cystgastrostomy ± necrosectomy between 2009 and 2017 were identified by a retrospective chart review. All available preprocedure and postprocedure imaging was reviewed for evidence of isolated distal pancreatic tail remnants.

RESULTS

Seventy-four patients were included (40 surgical and 34 endoscopic). All the patients in the surgical group underwent laparoscopic transgastric necrosectomy; the endoscopic group consisted of 26 patients for pseudocyst drainage and eight patients for necrosectomy. A disconnected pancreatic tail was identified in 22 (29%) patients (13 laparoscopic and nine endoscopic). After the creation of the "cystgastrostomy," there were no external fistulas despite the viable tail. Of the 22 patients, four patients developed symptoms at a median of 23 months (two, recurrent episodic pancreatitis; two, intractable pain). Two patients (both initially in endoscopic group) ultimately required distal pancreatectomy and splenectomy at 24 and 6 months after index procedure.

CONCLUSIONS

Patients with a walled-off retrogastric collection and an isolated viable tail are effectively managed by a transgastric approach. Despite this seemingly "unstable anatomy," the creation of an internal fistula via surgical or endoscopic "cystgastrostomy" avoids external fistulas/drains and the short-term necessity of surgical distal pancreatectomy. A very small subset requires intervention for late symptoms.