A multi-institutional consensus on how to perform endoscopic ultrasound-guided peri-pancreatic fluid collection drainage and endoscopic necrosectomy

Role of endoscopic ultrasonography in the management of peripancreatic collections. Diagnostic and therapeutic approach

Pancreatic fluid collections are surrounded by a wall of granulation tissue and may contain necrotic debris. They occur following a severe acute pancreatitis and most of the cases resolve spontaneously after several weeks. However, their management may lead to a very hardto-treat condition, requiring a multidisciplinary approach. During the last decades we assisted to a change of paradigm involving Endoscopic Ultrasonography, from a pure diagnostic technique to an interventional-therapeutic one, allowing an effective, safe and less invasive approach than other existing treatment standards, historically consisting of surgical and percutaneous drainage. Treatment of pancreatic fluid collections is indicated if they become infected or symptomatic. Over the past years, exponential developments were done in interventional endoscopic approach, making it the first line suggested modality. The use of endoscopic ultrasound allows assessment of the collection, even when it is not directly bulging on gastrointestinal wall, creation of an internal fistulous tract, checking for surrounding vessels with the use of Doppler, and deployment of a stent avoiding the discomfort of external tubes. Several types of stent have been used for endoscopic drainage: plastic double pigtail stents, fully covered self-expanding metal stents and, more recently, lumen apposing metal stents, which are considered revolutionary because of their two-side flanges and wide and short internal channel, a new design that made easier direct endoscopic necrosectomy. This review aims to go through currently available literature on the diagnostic and therapeutic role of Endoscopic Ultrasonography to handle pancreatic fluid collections.

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.

Direct Endoscopic Necrosectomy With and Without Hydrogen Peroxide for Walled-off Pancreatic Necrosis: A Multicenter Comparative Study

INTRODUCTION

Endoscopic necrosectomy has emerged as the preferred treatment modality for walled-off pancreatic necrosis. This study was designed to evaluate the safety and efficacy of direct endoscopic necrosectomy with and without hydrogen peroxide (H2O2) lavage.

METHODS

Retrospective chart reviews were performed for all patients undergoing endoscopic transmural management of walled-off pancreatic necrosis at 9 major medical centers from November 2011 to August 2018. Clinical success was defined as the resolution of the collection by imaging within 6 months, without requiring non-endoscopic procedures or surgery.

RESULTS

Of 293 patients, 204 met the inclusion criteria. Technical and clinical success rates were 100% (204/204) and 81% (166/189), respectively. For patients, 122 (59.8%) patients had at least one H2O2 necrosectomy (H2O2 group) and 82 (40.2%) patients had standard endoscopic necrosectomy. Clinical success was higher in the H2O2 group: 106/113 (93.8%) vs 60/76 (78.9%), P = 0.002. On a multivariate analysis, the use of H2O2 was associated with higher clinical success rate (odds ratio 3.30, P = 0.033) and earlier resolution (odds ratio 2.27, P < 0.001). During a mean follow-up of 274 days, 27 complications occurred. Comparing procedures performed with and without H2O2 (n = 250 vs 183), there was no difference in post-procedure bleeding (7 vs 9, P = 0.25), perforation (2 vs 3, P = 0.66), infection (1 vs 2, P = 0.58), or overall complication rate (n = 13 [5.2%] vs 14 [7.7%], P = 0.30).

DISCUSSION

H2O2-assisted endoscopic necrosectomy had a higher clinical success rate and a shorter time to resolution with equivalent complication rates relative to standard necrosectomy.See the visual abstract at http://links.lww.com/AJG/B714.(Equation is included in full-text article.).

Training in advanced bilio-pancreatic endoscopy

As the clinical applications of endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) take more and more root in everyday practice and these endoscopic procedures become increasingly more complex and interventional with a higher chance for complications, the demand for expert bilio-pancreatic endoscopists continues to increase. In response to this growing need, specific postgraduate fellowships have been developed, however the standardization of training programs and the assessment of the achieved competence still remains an open debate. ERCP and EUS competency often requires training beyond the scope of a standard GI fellowship program, which lasts at least 1-2 years, and there are some differences in the way to face the issues of advanced bilio-pancreatic endoscopy training between Europe, America and the Asian regions. Today there is no role for the self-teaching of ERCP and EUS through trial and error without supervision and, in the near future, it is necessary to critically revise current training guidelines, to establish a standardized curriculum for advanced bilio-pancreatic endoscopists and to implement universally validated skill assessment tools, able to ensure constant and targeted feedback to trainees.

Endoscopic ultrasound-guided gallbladder drainage: a technical review

Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) has emerged as a safe and effective minimally invasive alternative to both percutaneous and endoscopic transpapillary GBD in patients with acute cholecystitis. Over the last few years, the technique, as well as the indications for EUS-GBD have been gradually evolving, and the procedure has become simpler and safer as the accepted indications have expanded. The development of lumen-apposing metal stents (LAMS) has allowed us to realize the dream of creating endoscopic gastrointestinal anastomoses, and has thus paved the way for a safer EUS-GBD. Single step EUS-guided LAMS delivery systems have obviated the use of other endoscopic accessories and thus made EUS-GBD simpler and safer. However, EUS-GBD can be associated with potentially serious complications, and therefore should be performed by expert interventional endosonologists at centers with surgical and radiological back up. EUS-GBD is a relatively new procedure still in its infancy, but continued improvement in EUS accessories and dedicated stents will make this procedure safer and also expand its current indications. This review focuses on the technical aspects, including procedural details, as well as the complications of EUS-GBD.

EUS in Pediatrics: A Multicenter Experience and Review

Background/Aim: Endoscopic ultrasound (EUS) is a well-established tool used in the evaluation and treatment of a wide range of pathologies in adult medicine. EUS in pediatrics has been shown to be safe and technically effective, and its use continues to evolve. This article aims to describe the EUS experience at our tertiary-care centers with regard to safety, technical success, and its impact in clinical management. We also discuss the current and developing diagnostic and therapeutic uses for EUS in pediatrics such as in pancreaticobiliary disease, congenital anomalies, eosinophilic esophagitis, inflammatory bowel disease, and liver disease. Methods: This is a retrospective review of EUS performed by two pediatric gastroenterologists trained as endosonographers between April 2017 and November 2020. Patient demographics, procedure indication, procedure characteristics, technical success, and complications were collected. Literature review was performed to describe current and future uses of EUS in pediatrics. Results: Ninety-eight EUS were performed with 15 (15.3%) including fine needle aspiration/biopsy and 9 (9.2%) cases being therapeutic. Most common indications include choledocholithiasis (n = 31, 31.6%), pancreatic fluid collections (n = 18, 18.4%), chronic and acute recurrent pancreatitis (n = 14, 14.3%), and acute pancreatitis characterization (n = 13, 13.3%). Notable indications of pancreatic mass (n = 6, 6.1%) and luminal lesions/strictures (n = 6, 6.1%) were less common. Complications were limited with one instance of questionable GI bleeding after cystgastrostomy creation. Ninety-eight of 98 (100%) cases were technically successful. Conclusion/Discussion: EUS has been shown to be performed safely and successfully in the pediatric population by pediatric endosonographers. This study and review support its use in pediatric practice and demonstrate the wide variety of indications for EUS such as pancreatic cystgastrostomy, celiac plexus neurolysis, and evaluation of chronic pancreatitis. This literature review also demonstrates areas of potential development for EUS within the practice of pediatric gastroenterology.

The role of solid debris in endoscopic ultrasound-guided drainage of walled-off necrosis: A large cohort study

BACKGROUND AND AIM

The effect of solid debris on walled-off necrosis (WON) drainage remains unknown. Our study evaluated the role of solid debris in endoscopic ultrasound (EUS)-guided drainage of WON compared lumen-apposing metal stent (LAMS) with double-pigtail plastic stent (DPPS).

METHODS

We retrospectively evaluated consecutive patients with WON who underwent EUS-guided drainage in our endoscopic center over a 9-year period. The amount of solid debris in WON was assessed with computed tomography or magnetic resonance imaging and EUS images.

RESULTS

From 2011 to 2019, 84 WON patients were included. In WON with < 20% solid debris, the short-term clinical success of LAMSs (96.8%) was significantly higher than DPPSs (66.7%) (P = 0.03), and LAMSs were safer than DPPSs with less early adverse events (P = 0.02) and late adverse events (P = 0.03). On multivariable analysis, DPPS (odds ratio [OR], 0.16; 95% confidence interval [CI], 0.04-0.65; P = 0.01) and solid debris > 40% (OR, 0.11; 95% CI, 0.02-0.62; P = 0.01) were the predictors for failure of resolution of WON after adjusting for age and cyst size. The number of DPPSs used was significantly higher than LAMSs in managing WONs (P < 0.001).

CONCLUSION

For WON with < 20% solid debris, LAMSs might superior to DPPSs in terms of efficacy and safety.

Do we need contrast agents for EUS?

We recently introduced a series of articles that dealt with controversies in EUS. In Part I, the authors discussed which clinical information is necessary prior to EUS and whether other imaging modalities are required before embarking on EUS examinations. Part II focuses on technical details and controversies about the use of EUS in special situations. In this article, important practical issues regarding the application of contrast-enhanced EUS in various clinical settings are raised and controversially discussed from different points of view.

Innovation of EUS-guided transmural gallbladder drainage using a novel self-expanding metal stent

Endoscopic ultrasonography (EUS)-guided transmural drainage has been accepted as a modality of choice in peripancreatic fluid collection and acute cholecystitis. Each type of stent, including double-pigtail plastic stents, tubular self-expandable metal stents (SEMS), and lumen-apposing metal stents, for these procedure has its own advantages and disadvantages. To overcome their disadvantages, this animal study evaluated the feasibility of a newly designed twisted fully covered SEMS with spiral coiled ends. We performed the EUS-guided cholecystogastrostomy with a newly developed metal stent in eight mini pigs with surgically induced gallbladder distension. This novel stent is a twisted fully covered SEMS with spiral coiled ends, a diameter of 8 mm, and a length of 6 cm. The stent has been maintained for four to seven weeks after EUS-guided cholecystogastrostomy. The primary outcome was the technical success rate, and the secondary outcomes were adverse events, stent dysfunction, stent removability, and fistula formation. The stent was placed successfully between the gallbladder and the stomach in all cases without any adverse event. We observed neither stent migration nor dysfunction during the study period, and all the stents were removed easily as scheduled. We confirmed successful cholecysto-gastric fistula formation at endoscopic and histologic level in all cases. EUS-guided transmural drainage and fistula formation using a new twisted fully covered metal stent with spiral coiled ends was technically feasible without any adverse event in this animal study. Further clinical studies are needed to evaluate its efficacy and safety in real practice.

Endoscopic Ultrasound Guided Pancreatic Pseudocyst drainage experience at a tertiary care unit

Objective:

To evaluate the clinical success, technical success and complications related to Endoscopic ultrasound (EUS) guided Pancreatic pseudocyst (PPC) drainage.

Methods:

This retrospective study was conducted on the patients with symptomatic PPC who presented over a period of three years, between January 2015 and September 2018, at Endoscopic Suite of Surgical Unit 4, Civil Hospital, Karachi. Record was analyzed for demographic data, indications for the procedure, complications and success related to EUS guided drainage. Statistical analyses were performed using the SPSS Version 22.

Results:

Total number of patients was 71. Mean age was 37.20 ± 17.27 years with a range of 6 to 68 years. Complications occurred in 12 (8.52%) patients, including stent migration (5/12), bleeding (4/12), infection (1/12), intra-abdominal abscess (1/12) and perforation (1/12). Technical success was achieved in 100% and clinical success in 97.1%. There was no procedure-related mortality.

Conclusion:

Pancreatic pseudocyst (PPC) is a known complication of acute as well as chronic pancreatitis which can have dreaded and appalling effects. In this part of the world with limited and scarce resources, EUS guided drainage of PPC is most feasible and rational with minimal complications, thus making it a front runner procedure.

Endoscopic pancreatic necrosectomy in the United States-Mexico border: A cross sectional study

BACKGROUND

A recent expert panel issued recommendations about the technical aspects of direct endoscopic necrosectomy (DEN) for pancreatic walled-off necrosis (WON). However, significant technical heterogeneity still exists among endoscopists.

AIM

To report the outcomes of our DEN technique and how it differs from a recent expert consensus statement and previous studies.

METHODS

Medical records of patients with WON who underwent DEN from September 2016 - May 2019 were queried for the following information: Age, gender, ethnicity, etiology of acute pancreatitis, WON location and size, DEN technical information, adverse events (AEs) and outcomes. Adverse events were graded according to the American Society of Gastrointestinal Endoscopy Lexicon grading system. Technical success was defined as adequate lumen apposing metal stent (LAMS) deployment plus removal of ≥ 90% of necrosum. Clinical success was defined as complete resolution of WON cavity by imaging and resolution of symptoms at ≤ 3 months (mo) after last DEN. Data analysis was performed using mean and standard deviation for continuous variables, frequency and proportion for categorical variables, and median and range for interval data.

RESULTS

A total of 21 patients underwent DEN. Most of them were Hispanic and their mean age was 51 ± 17 years. The majority of the collections were located in the body of the pancreas and the mean size was 13 cm ± 5 cm. The most common indication was persistent vomiting. Antibiotics were administered only in cases of infected necrosis. All LAMS were placed without radiological guidance, dilated the same day of deployment and removed after a mean of 27 ± 11 d. Routine cross-sectional imaging immediately after drainage was not performed. The mean interval between DEN sessions was 7 ± 4 d and the mean number of DEN/patient was 3 ± 2. Technical and clinical success rates were both 95%. AEs were seen in 5 patients and included: Sepsis (2), stent migration (1), stent maldeployment (1), perforation (1). The sensitivity and positive predictive value of an occluded LAMS leading to sepsis was 50% and 0.11 respectively. No fatalities were observed.

CONCLUSION

Our DEN technique differed significantly from the one recommended by a recent expert panel and the one published in previous studies. Despite these differences excellent clinical outcomes were obtained.

The Roles of Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography in the Evaluation and Treatment of Chronic Pancreatitis in Children: A Position Paper From the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Pancreas Committee

INTRODUCTION

Pediatric chronic pancreatitis is increasingly diagnosed. Endoscopic methods [endoscopic ultrasound (EUS), endoscopic retrograde cholangiopancreatography (ERCP)] are useful tools to diagnose and manage chronic pancreatitis. Pediatric knowledge and use of these modalities is limited and warrants dissemination.

METHODS

Literature review of publications relating to use of ERCP and EUS for diagnosis and/or management of chronic pancreatitis with special attention to studies involving 0--18 years old subjects was conducted with summaries generated. Recommendations were developed and voted upon by authors.

RESULTS

Both EUS and ERCP can be used even in small children to assist in diagnosis of chronic pancreatitis in cases where cross-sectional imaging is not sufficient to diagnose or characterize the disease. Children under 15 kg for EUS and 10 kg for ERCP can be technically challenging. These procedures should be done optimally by appropriately trained endoscopists and adult gastroenterology providers with appropriate experience treating children. EUS and ERCP-related risks both include perforation, bleeding and pancreatitis. EUS is the preferred diagnostic modality over ERCP because of lower complication rates overall. Both modalities can be used for management of chronic pancreatitis -related fluid collections. ERCP has successfully been used to manage pancreatic duct stones.

CONCLUSION

EUS and ERCP can be safely used to diagnose chronic pancreatitis in pediatric patients and assist in management of chronic pancreatitis-related complications. Procedure-related risks are similar to those seen in adults, with EUS having a safer risk profile overall. The recent increase in pediatric-trained specialists will improve access of these modalities for children.

The safety and efficacy of a new 20-mm lumen apposing metal stent (lams) for the endoscopic treatment of pancreatic and peripancreatic fluid collections: a large international, multicenter study

BACKGROUND

Lumen apposing metal stent (LAMS) allows an easy access to peripancreatic fluid collections (PPFCs) and the possibility of performing direct endoscopic necrosectomy (DEN). The aim of our study was to evaluate the safety and efficacy of a new 20-mm LAMS in the management of PPFCs. This novel stent represents the largest diameter LAMS available on the market to date.

METHODS

This is an international, multicenter retrospective study involving 20 centers. Consecutive patients who underwent EUS-guided PPFC drainage using a 20-mm LAMS were included. Primary outcomes were technical and clinical success. Secondary outcomes were rate and the severity of adverse events.

RESULTS

A total 105 patients underwent PPFC drainage using the new 20-mm LAMS and 106 LAMS were placed. Technical success was 100% (106/106). 7/105 patients died due to causes not related to the stent. Clinical success was achieved in 92/98 patients (93.9%). Significant adverse events occurred in 8/98 patients (8.16%): 4 cases (4.08%) of bleeding, 3 cases (3.06%) of suprainfection, 1 case of gastric outlet obstruction.

CONCLUSIONS

This multicenter study demonstrated acceptable rates of technical and clinical success using a new 20-mm LAMS for PPFC, including walled-off pancreatic necrosis (WOPN). The results of our study suggest that a new 20-mm LAMS is non-inferior in terms of safety, efficacy, and adverse events as compared to smaller diameter LAMS in the management of PPFCs, including pancreatic psuedocysts (PP) and WOPN. Randomized controlled studies will be needed to determine the ideal size of LAMS need to achieve the greatest clinical benefit with the minimized risk exposure for this high-risk patient population.

Multicenter study of plastic vs. self-expanding metal stents in endoscopic ultrasound-guided drainage of walled-off pancreatic necrosis - PROMETHEUS: a randomized controlled trial protocol

BACKGROUND

It seems that lumen-apposing metal stents (LAMS) are displacing plastic stents in the therapy of pancreatic-fluid collection in walled-off necrosis (WON). To date, there is no quality of evidence to recommend LAMS as the standard treatment in the management of WON. The theoretical benefit of LAMS over plastic stents needs to be proven.

METHODS/DESIGN

This is a randomized controlled, multicenter, prospective clinical trial with two parallel groups, without masking. One-hundred and fourteen patients with WON will undergo endoscopic ultrasound (EUS)-guided transmural draining in nine tertiary hospitals in Spain and will be randomized to the LAMS or plastic-stent group. The primary endpoint is the short-term (4 weeks) clinical success determined by the reduction of the collection (to < 50% or < 5 cm in size), along with clinical improvement. Secondary endpoints: long-term (4 months) clinical success (total resolution or 5 cm), procedure duration, level of difficulty, safety, and recurrences.

DISCUSSION

The PROMETHEUS trial has been designed to determine whether LAMS are superior to plastic stents in EUS-guided transmural drainage of WON.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03100578. Registered on 4 April 2017. https://clinicaltrials.gov/ct2/home.

Walled-off Peripancreatic Fluid Collections in Asian Population: Paradigm Shift from Surgical and Percutaneous to Endoscopic Drainage

BACKGROUND AND OBJECTIVES

Drainage of symptomatic walled-off peripancreatic fluid collections (WPFCs) can be achieved by endoscopic, percutaneous, and surgical techniques. The aim of this study was to determine the current trends in management of WPFCs and the outcome of such modalities in Asian population.

METHODS

In this retrospective analysis, all patients diagnosed with pancreatitis from 2013 to 2016 in King Chulalongkorn Memorial Hospital, Bangkok, Thailand, were analyzed. Relevant clinical data of all patients with peripancreatic fluid collections (PFCs) was reviewed. Clinical success was defined as improvement in symptoms after drainage.

RESULTS

Of the total 636 patients with pancreatitis, 72 (11.3%) had WPFCs, of which 55 (8.6%) and 17 (2.7%) had pancreatic pseudocyst (PP) and walled-off necrosis (WON), respectively. The commonest etiologies of WPFCs were alcohol (38.9%) and biliary stone (29.2%). Post-procedure and pancreatic tumor related pancreatitis was found in 8.3% and 6.9% patients, respectively. PP was more common in chronic (27.8%) than acute (5.5%) pancreatitis. Of the 72 patients with WPFCs, 31 (43.1%) had local complications. Supportive, endoscopic, percutaneous, and surgical drainage were employed in 58.3%, 27.8%, 8.3%, and 5.6% with success rates being 100%, 100%, 50%, and 100%, respectively. Complications that developed after percutaneous drainage included bleeding at procedure site (n = 1), infection of PFC (n = 1), and pancreatic duct leakage (n = 1).

CONCLUSION

Over the past few years, endoscopic drainage has become the most common route of drainage of WPFCs followed by percutaneous and surgical routes. The success rate of endoscopic route is better than percutaneous and comparable to surgical modality.

Endoscopic Necrosectomy of Walled-Off Necrosis following Severe Pancreatitis Using a Hot AxiosTM Stent - A Case Series

BACKGROUND

Walled-off necrosis is a common complication of severe pancreatitis. Guidelines recommend endoscopic transgastric necrosectomy as therapy of choice. Different endoscopic approaches are possible.

METHODS

We retrospectively analyzed our series of 9 patients where necrosectomy was performed after application of a lumen-apposing metal stent (LAMS) delivered using a Hot AxiosTM Stent device.

RESULTS

In all 9 cases, the walled-off necrosis resolved completely. Necrosectomy was performed through the LAMS (mean: 5.7 times). Endoscopic necrosectomy was repeated every 3rd-7th day using 10- or 15-mm snares. There were no major complications. Especially, no early or delayed bleeding was seen.

CONCLUSION

The Hot AxiosTM Stent device is a safe method for necrosectomy of walled-off necrosis. It enables puncture, drainage, and LAMS insertion in a single delivery, followed by several courses of necrosectomy if needed without stent exchange.

Lumen-apposing metal stents in management of pancreatic fluid collections: The nobody's land of removal timing

Pancreatic fluid collections (PFCs) develop as a result of damage to the major or peripheral pancreatic ducts, complication due to acute or chronic pancreatitis, trauma or iatrogenic causes. PFCs include pancreatic pseudocysts (PPs) and walled-off necrosis (WON). PFCs usually resolve spontaneously and are asymptomatic, but if they persist, increase in dimension or became symptomatics, therapeutic intervention is required. Available therapeutic interventions include surgical, percutaneous, and endoscopic drainage. The endoscopic approach is nowadays considered the first line-treatment of PFCs due to various advantages when compared with surgical or percutaneous drainage: decreased morbidity, length of hospital stay, and reduced costs. In the last few years, the endoscopic ultrasound (EUS)-guided transmural drainage, initially with plastic stents, gained popularity. More recently, fully covered self-expanding lumen-apposing metal stents (LAMS) have been demonstrated to be both, safe and effective with high clinical and technical success, reducing the risk of perforation, peritoneal leakage, migration and facilitating the drainage of necrotic contents. In the last few years, several studies evaluating the safety and efficacy of LAMS and their differences with plastic stents have been performed, but literature on the removal timing of this device and associated complications is still limited. The aim of this review is to analyze studies reporting information about the retrieval timing of LAMS and the related adverse events.

New insights into acute pancreatitis

The incidence of acute pancreatitis continues to increase worldwide, and it is one of the most common gastrointestinal causes for hospital admission in the USA. In the past decade, substantial advancements have been made in our understanding of the pathophysiological mechanisms of acute pancreatitis. Studies have elucidated mechanisms of calcium-mediated acinar cell injury and death and the importance of store-operated calcium entry channels and mitochondrial permeability transition pores. The cytoprotective role of the unfolded protein response and autophagy in preventing sustained endoplasmic reticulum stress, apoptosis and necrosis has also been characterized, as has the central role of unsaturated fatty acids in causing pancreatic organ failure. Characterization of these pathways has led to the identification of potential molecular targets for future therapeutic trials. At the patient level, two classification systems have been developed to classify the severity of acute pancreatitis into prognostically meaningful groups, and several landmark clinical trials have informed management strategies in areas of nutritional support and interventions for infected pancreatic necrosis that have resulted in important changes to acute pancreatitis management paradigms. In this Review, we provide a summary of recent advances in acute pancreatitis with a special emphasis on pathophysiological mechanisms and clinical management of the disorder.

Complications of endoscopic ultrasound-guided transmural drainage of pancreatic fluid collections and their management

The development of endoscopic ultrasound (EUS)-guided drainage techniques and lumen-apposing metal stents (LAMS) has markedly reduced the complication rate of endoscopic transmural drainage of pancreatic collections and made these procedures safer and more effective. Despite its improved safety profile, various types of complications, some even life-threatening, can occur after EUS-guided drainage of pancreatic fluid collections. Stent maldeployment/migration, bleeding, gastrointestinal perforation, and air embolism are important complications of EUS-guided drainage of pancreatic collections. Delayed complications weeks after the procedure, such as bleeding and buried LAMS due to the presence of prolonged indwelling transmural stents, have also been described. Careful patient selection, with proper assessment of the size, solid necrotic content and location of the collection, as well as an in-depth understanding of various risk factors that predict complications, are important for a safer and more effective endoscopic transmural drainage. For a better clinical outcome, it is important for the endoscopist to know about various complications of EUS-guided drainage of pancreatic collections, as well as their appropriate management strategies.

New Concept for a Thoracic Drainage System Using Magnetic Actuation

Objectives. Thoracic drainage is a common procedure to drain fluid, blood, or air from the pleural cavity. Some attempts to develop approaches to new thoracic drainage systems have been made; however, a simple tube is often currently used. The existing drain presupposes that it is placed correctly and that the tip does not require moving after insertion into the thoracic cavity. However, in some cases, the drain is not correctly placed and reinsertion of an additional drain is required, resulting in significant invasiveness to the patient. Therefore, a more effective drainage system is needed. This study aimed to develop and assess a new thoracic drain via a collaboration between medical and engineering personnel. Methods. We developed the concept of a controllable drain system using magnetic actuation. A dry laboratory trial and accompanying questionnaire assessment were performed by a group of thoracic and general surgeons. Objective mechanical measurements were obtained. Porcine experiments were also carried out. Results. In a dry laboratory trial, use of the controllable drain required significantly less time than that required by replacing the drain. The average satisfaction score of the new drainage system was 4.07 out of 5, indicating that most of the research participants were satisfied with the quality of the drain with a magnetic actuation. During the porcine experiment, the transfer of the tip of the drain was possible inside the thoracic cavity and abdominal cavity. Conclusion. This controllable thoracic drain could reduce the invasiveness for patients requiring thoracic or abdominal cavity drainage.

An overview of walled-off pancreatic necrosis for clinicians

Walled of pancreatic necrosis (WOPN) is a new term coined for encapsulated fluid collection developing after acute necrotising pancreatitis (ANP). It is a heterogeneous collection containing varying amount of liquid as well as solid necrotic material. The literature on its natural history as well as appropriate management is gradually expanding thereby improving treatment outcomes of this enigmatic disease. Areas covered: This review discusses currently available literature on etiology, frequency, natural history, and imaging features WOPN. Also, updated treatment options including endoscopic, radiological and surgical drainage are discussed. Expert opinion: WOPN is alocal complication of ANP occurring in the delayed phase of ANP and may be asymptomatic (50%) or present with pain, fever, jaundice, or gastric outlet obstruction. Natural courses of asymptomatic WOPN have been infrequently studied, and it appears that the majority remain asymptomatic and resolve spontaneously. Magnetic resonance imaging and endoscopic ultrasound are the best imaging modalities to evaluate solid necrotic debris. Symptomatic WOPN usually needs immediate drainage, this can be done endoscopically, radiologically, or surgically. Current evidence suggests that endoscopic transluminal drainage is the preferred drainage technique as it is effective and associated with lower mortality, risk of organ failure, adverse effects, and length of hospital stay.

Retrievable puncture anchor traction method for EUS-guided gallbladder drainage: a porcine study

BACKGROUND AND AIMS

EUS-guided gallbladder drainage (EUS-GBD) is a challenging technique for endoscopists that requires a high level of skill. EUS-GBD is challenging because the gallbladder can be easily collapsed. To resolve this issue, we aimed to develop a retrievable puncture anchor traction (RPAT) method for EUS-GBD. We evaluated and compared the success rate, safety, and outcomes of the RPAT method for EUS-GBD against EUS-GBD without RPAT using a porcine model.

METHODS

In total, 16 Bama mini pigs (weighing 15-20 kg) were randomly divided into an experimental group (n = 8) and a control group (n = 8). The RPAT method was performed in the experimental group and EUS-GBD without retrievable puncture anchor was performed in the control group. Incidence of operative adverse events, wound healing, and success rates of EUS-GBD were compared and analyzed between the experimental group and the control group.

RESULTS

All EUS-GBD procedures were successfully performed in all 8 animals in the experimental group (100%). However, in the control group, EUS-GBD was successfully performed only on 4 pigs (50%); the remaining 4 pigs died because of EUS-GBD failure caused by gallbladder collapse leading to unsuccessful frontal stent release.

CONCLUSIONS

RPAT helped increase the success rate of EUS-GBD and could reduce gallbladder collapse. Therefore, we believe this method can be applied to EUS-GBD in the near future. Furthermore, RPAT will enhance the safety of EUS-GBD.

Lumen-apposing metal stents (LAMS) versus plastic stents for EUS-guided drainage of walled-off necrosis (WON) (LVPWON): study protocol for a multicenter randomized controlled trial

BACKGROUND

Endoscopic ultrasonography (EUS)-guided drainage has become the first-line therapy for late peri-pancreatic fluid collection (PFC). Double pigtail plastic stents (DPPS) and lumen-apposing metal stents (LAMS) are commonly used for PFC drainage. Recently, a multi-institutional consensus on PFC drainage has recommended that LAMS should be the standard care for patients with walled-off necrosis (WON). However, given the poor quality of evidence, we aim to perform a large-scale randomized controlled trial to determine whether LAMS is superior to DPPS for WON drainage.

METHODS/DESIGN

The study is an open-label, prospective, parallel-group, superiority, multicenter randomized controlled trial. Two hundred and fifty-six patients with WON who will attend 18 tertiary hospitals in China will be randomly allocated to the LAMS or DPPS group before the procedure. The primary endpoint is the clinical success at one month after drainage (reduction in the size of WON to < 2 cm). Secondary endpoints include technical success, operation time, recurrence, adverse events, and secondary interventions.

DISCUSSION

The LVPWON trial is designed to determine whether LAMS is effective, safe, and superior to DPPS for WON drainage.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03027895 . Registered on 14 January 2017.

Safety and rate of delayed adverse events with lumen-apposing metal stents (LAMS) for pancreatic fluid collections: a multicenter study

Background and study aims  Endoscopic drainage with dedicated lumen-apposing metal stents (LAMS) is routinely performed for symptomatic pancreatic fluid collections (PFCs), walled-off necrosis (WON) and pseudocyst (PP). There has been increasing concern regarding delayed adverse events associated with the indwelling LAMS.  Patients and methods  Multicenter retrospective analysis of consecutive patients who underwent endoscopic ultrasound (EUS)-guided LAMS placement for PFC from January 2010 to May 2017. Main outcomes included: (1) resolution of the PFC, (2) rate of delayed adverse events at follow-up, and (3) predictors of treatment failure and delayed adverse events on logistic regression. Results  A total of 122 patients (mean age 50.9 years, 68 % male) underwent LAMS insertion for 64 WON (98.4 %) and 58 PP (98.3 %). PFC mean size was 10.6 cm. PFC resolution was significantly lower for WON (62.3 %) vs. PP (96.5 %) ( P  < 0.001) on imaging at a median of 4 weeks. Stent occlusion was identified in 18 (29.5 %) and 10 (17.5 %) patients with WON and PP, respectively ( P  = 0.13). There were no cases of delayed bleeding or buried stent on follow-up endoscopy. Use of electrocautery-enhanced LAMS was the only factor associated with treatment failure of WON (OR = 13.2; 95 % ci: 3.33 - 51.82, P  = 0.02) on logistic regression. There were no patient, operator, or procedure-related factors predictive of stent occlusion. Conclusions  EUS-guided LAMS for PFC is associated with a low incidence of delayed adverse events. While nearly all PPs resolve at 4 weeks permitting LAMS removal shortly thereafter, many WON persist, with use of electrocautery-enhanced LAMS being the sole predictor of treatment failure.

Endoscopic ultrasound-guided transmural drainage by cautery-tipped lumen-apposing metal stent: exploring the possible indications

Background

The recently introduced Hot AXIOS™ system for endoscopic ultrasound (EUS)-guided transenteric drainage has the potential to change interventional endoscopy significantly. The aim of our study was to assess the effectiveness and safety of this new type of lumen-apposing metal stent (LAMS) with cautery system for pancreatic collection, and gallbladder and biliary tree drainage.

Methods

We retrospectively reviewed consecutive patients undergoing EUS-guided drainage by LAMS with cautery system in a tertiary-care academic medical center between March 2014 and March 2017. All patients were included in our prospectively maintained institutional EUS database. The main outcome measures were technical success, clinical effectiveness, and adverse events.

Results

A total of 45 patients (20 men, mean age 69.6 years) underwent LAMS placement. Indications were pancreatic fluid collections (19 patients, 42.2%), acute cholecystitis (10 patients, 22.2%), and biliary drainage (16 patients, 35.5%). Technical success was achieved in all patients except one (97.7%). Clinical success was achieved in 86.4% (38/44) of cases and adverse events occurred in 5 (11.4%) of patients.

Conclusions

In our experience, EUS-guided LAMS placement performed by expert endoscopists was feasible and effective in the endoscopic management of pancreatic fluid collection, and biliary and gallbladder drainage. Optimization of transmural drainage by new dedicated devices could improve efficacy and safety in appropriately selected patients.