Proposal of classification and terminology of interventional endoscopic ultrasonography/endosonography.

Interventional endoscopic ultrasonography/endosongraphy (I-EUS) procedures have rapidly evolved since their introduction three decades ago; however, the classification and terminology for these procedures remain unstandardized. To address this, the Subcommittee for Terminology of I-EUS in the Japan Gastroenterological Endoscopy Society was established to define classifications and a glossary of I-EUS terms. They categorized I-EUS procedures into five types based on purpose and method: (i) EUS-guided sampling; (ii) EUS-guided through-the-needle examination; (iii) EUS-guided drainage/anastomosis (EUS-D/A); (iv) trans-endosonographically/EUS-guided created route (ESCR) procedures; and (v) EUS-guided delivery. EUS-guided sampling includes tissue acquisition and fluid sampling, classified by needle type into fine needle aspiration and fine needle biopsy. Through-the-needle examinations include imaging, measurements, and biopsies. EUS-D/A includes organ drainage/anastomosis, fluid collection drainage, and digestive tract anastomosis. In the EUS-D/A route, "anastomosis" is used for organ-to-organ procedures, whereas "tract" is for fluid drainage. ESCR is a newly proposed term for procedures via anastomosis or tract, such as endoscopic necrosectomy and EUS-guided antegrade stenting. The term "trans-luminal drainage/anastomosis stent" is used for stents that maintain the ESCR rather than treating strictures. EUS-guided delivery involves the delivery of substances, such as fluids, drugs, medical devices, and energy. This proposed categorization and terminology aimed to clarify I-EUS procedures and will require updates as new techniques and concepts emerge.

Forward viewing liner echoendoscopy for therapeutic interventions.

Therapeutic endoscopic ultrasonography (EUS) procedures using the forward-viewing convex EUS (FV-EUS) have been reviewed based on the articles reported to date. The earliest reported procedure is the drainage of pancreatic pseudocysts using FV-EUS. However, the study on drainage of pancreatic pseudocysts focused on showing that drainage is possible with FV-EUS rather than leveraging its features. Subsequently, studies describing the characteristics of FV-EUS have been reported. By using FV-EUS in EUS-guided choledochoduodenostomy, double punctures in the gastrointestinal tract can be avoided. In postoperative modified anatomical cases, using the endoscopic function of FV-EUS, procedures such as bile duct drainage from anastomosis, pancreatic duct drainage from the afferent limb, and abscess drainage from the digestive tract have been reported. When a perpendicular puncture to the gastrointestinal tract is required or when there is a need to insert the endoscope deep into the gastrointestinal tract, FV-EUS is considered among the options.

Malignant gastric outlet obstruction: Which is the best therapeutic option?

Malignant gastric outlet obstruction (MGOO) is a clinical condition characterized by the mechanical obstruction of the pylorus or the duodenum due to tumor compression/infiltration, with consequent reduction or impossibility of an adequate oral intake. MGOO is mainly secondary to advanced pancreatic or gastric cancers, and significantly impacts on patients' survival and quality of life. Patients suffering from this condition often present with intractable vomiting and severe malnutrition, which further compromise therapeutic chances. Currently, palliative strategies are based primarily on surgical gastrojejunostomy and endoscopic enteral stenting with self-expanding metal stents. Several studies have shown that surgical approach has the advantage of a more durable relief of symptoms and the need of fewer re-interventions, at the cost of higher procedure-related risks and longer hospital stay. On the other hand, enteral stenting provides rapid clinical improvement, but have the limit of higher stent dysfunction rate due to tumor ingrowth and a subsequent need of frequent re-interventions. Recently, a third way has come from interventional endoscopic ultrasound, through the development of endoscopic ultrasound-guided gastroenterostomy technique with lumen-apposing metal stent. This new technique may ideally encompass the minimal invasiveness of an endoscopic procedure and the long-lasting effect of the surgical gastrojejunostomy, and brought encouraging results so far, even if prospective comparative trial are still lacking. In this Review, we described technical aspects and clinical outcomes of the above-cited therapeutic approaches, and discussed the open questions about the current management of MGOO.

Endosonography-guided gallbladder drainage versus percutaneous cholecystostomy in very high-risk surgical patients with acute cholecystitis: an international randomised multicentre controlled superiority trial (DRAC 1).

OBJECTIVE: The optimal management of acute cholecystitis in patients at very high risk for cholecystectomy is uncertain. The aim of the current study was to compare endoscopic ultrasound (EUS)-guided gallbladder drainage (EUS-GBD) to percutaneous cholecystostomy (PT-GBD) as a definitive treatment in these patients under a randomised controlled trial. DESIGN: Consecutive patients suffering from acute calculous cholecystitis but were at very high-risk for cholecystectomy were recruited. The primary outcome was the 1-year adverse events rate. Secondary outcomes include technical and clinical success, 30-day adverse events, pain scores, unplanned readmissions, re-interventions and mortalities. RESULTS: Between August 2014 to February 2018, 80 patients were recruited. EUS-GBD significantly reduced 1 year adverse events (10 (25.6%) vs 31 (77.5%), p<0.001), 30-day adverse events (5 (12.8%) vs 19 (47.5%), p=0.010), re-interventions after 30 days (1/39 (2.6%) vs 12/40 (30%), p=0.001), number of unplanned readmissions (6/39 (15.4%) vs 20/40 (50%), p=0.002) and recurrent cholecystitis (1/39 (2.6%) vs 8/40 (20%), p=0.029). Postprocedural pain scores and analgesic requirements were also less (p=0.034). The technical success (97.4% vs 100%, p=0.494), clinical success (92.3% vs 92.5%, p=1) and 30-day mortality (7.7% vs 10%, p=1) were statistically similar. The predictor to recurrent acute cholecystitis was the performance of PT-GBD (OR (95% CI)=5.63 (1.20-53.90), p=0.027). CONCLUSION: EUS-GBD improved outcomes as compared to PT-GBD in those patients that not candidates for cholecystectomy. EUS-GBD should be the procedure of choice provided that the expertise is available after a multi-disciplinary meeting. Further studies are required to determine the long-term efficacy. TRIAL REGISTRATION NUMBER: NCT02212717.

Lumen-apposing metal stents for malignant biliary obstruction: Is this the ultimate horizon of our experience?

In the last years, endoscopic ultrasonography (EUS) has evolved from a purely diagnostic technique to a more and more complex interventional procedure, with the possibility to perform several type of therapeutic interventions. Among these, EUS-guided biliary drainage (BD) is gaining popularity as a therapeutic approach after failed endoscopic retrograde cholangiopancreatography in distal malignant biliary obstruction (MBO), due to the avoidance of external drainage, a lower rate of adverse events and re-interventions, and lower costs compared to percutaneous trans-hepatic BD. Initially, devices created for luminal procedures (e.g., luminal biliary stents) have been adapted to the new trans-luminal EUS-guided interventions, with predictable shortcomings in technical success, outcome and adverse events. More recently, new metal stents specifically designed for transluminal drainage, namely lumen-apposing metal stents (LAMS), have been made available for EUS-guided procedures. An electrocautery enhanced delivery system (EC-LAMS), which allows direct access of the delivery system to the target lumen, has subsequently simplified the classic multi-step procedure of EUS-guided drainages. EUS-BD using LAMS and EC-LAMS has been demonstrated effective and safe, and currently seems one of the most performing techniques for EUS-BD. In this Review, we summarize the evolution of the EUS-BD in distal MBO, focusing on the novelty of LAMS and analyzing the unresolved questions about the possible role of EUS as the first therapeutic option to achieve BD in this setting of patients.

Current Status of Endoscopic Gallbladder Drainage.

The gold standard for treatment of acute cholecystitis is laparoscopic cholecystectomy. However, cholecystectomy is often not suitable for surgically unfit patients who are too frail due to various co-morbidities. As such, several less invasive endoscopic treatment modalities have been developed to control sepsis, either as a definitive treatment or as a temporizing modality until the patient is stable enough to undergo cholecystectomy at a later stage. Recent developments in endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) with endoscopic ultrasound EUS-specific stents having lumen-apposing properties have demonstrated potential as a definitive treatment modality. Furthermore, advanced gallbladder procedures can be performed using the stents as a portal. With similar effectiveness as percutaneous transhepatic cholecystostomy and lower rates of adverse events reported in some studies, EUS-GBD has opened exciting possibilities in becoming the next best alternative in treating acute cholecystitis in surgically unfit patients. The aim of this review article is to provide a summary of the various methods of gallbladder drainage GBD with particular focus on EUS-GBD and the many new prospects it allows.

Endoscopic Management of Gallbladder Stones: Can We Eliminate Cholecystectomy?

The gold standard for the management of acute cholecystitis is laparoscopic cholecystectomy. In patients that are not fit for surgery, percutaneous cholecystostomy is the standard treatment. However, the procedure is only a temporary measure for controlling gallbladder symptoms and it is frequently associated with morbidities. Recently, endoscopic options for management of acute cholecystitis have been developed. The approach avoids the need for a percutaneous drain and may allow endoscopic treatment of the gallstone. The aim of this article is to provide an overview on the current status of endoscopic management of acute cholecystitis.

Endoscopic ultrasonography-guided biliary drainage: Who, when, which, and how?

Both endoscopic ultrasonography (EUS)-guided choledochoduodenostomy (EUS-CDS) and EUS-guided hepaticogastrostomy (EUS-HGS) are relatively well established as alternatives to percutaneous transhepatic biliary drainage (PTBD). Both EUS-CDS and EUS-HGS have high technical and clinical success rates (more than 90%) in high-volume centers. Complications for both procedures remain high at 10%-30%. Procedures performed by endoscopists who have done fewer than 20 cases sometimes result in severe or fatal complications. When learning EUS-guided biliary drainage (EUS-BD), we recommend a mentor's supervision during at least the first 20 cases. For inoperable malignant lower biliary obstruction, a skillful endoscopist should perform EUS-BD before EUS-guided rendezvous technique (EUS-RV) and PTBD. We should be select EUS-BD for patients having altered anatomy from malignant tumors before balloon-enteroscope-assisted endoscopic retrograde cholangiopancreatography, EUS-RV, and PTBD. If both EUS-CDS and EUS-HGS are available, we should select EUS-CDS, according to published data. EUS-BD will potentially become a first-line biliary drainage procedure in the near future.

Direct therapeutic intervention for advanced pancreatic cancer.

Currently, chemotherapy is an accredited, standard treatment for unresectable, advanced pancreatic cancer (PC). However, it has been still showed treatment-resistance and followed dismal prognosis in many cases. Therefore, some sort of new, additional treatments are needed for the better therapeutic results for advanced PC. According to the previous reports, it is obvious that interventional endoscopic ultrasonography (EUS) is a well-established, helpful and low-risky procedure in general. As the additional treatments of the conventional therapy for advanced PC, many therapeutic strategies, such as immunotherapies, molecular biological therapies, physiochemical therapies, radioactive therapies, using siRNA, using autophagy have been developing in recent years. Moreover, the efficacy of the other potential therapeutic targets for PC using EUS-fine needle injection, for example, intra-tumoral chemotherapeutic agents (paclitaxel, irinotecan), several ablative energies (radiofrequency ablation and cryothermal treatment, neodymium-doped yttrium aluminum garnet laser, high-intensity focused ultrasound), etc., has already been showed in animal models. Delivering these promising treatments reliably inside tumor, interventional EUS may probably be indispensable existence for the treatment of locally advanced PC in near future.

Endoscopic ultrasound guided biliary drainage.

Endoscopic retrograde cholangio-pancreatography is the most appropriate technique for treating common bile duct and pancreatic duct stenosis secondary to benign and malignant diseases. Even if the procedure is performed by skillful endoscopist, there are patients in whom endoscopic stent placement is not possible. Common causes of failure include complex peri-papillary diverticula, prior surgery procedures, tumor involvement of the papilla, biliary sphincter stenosis, and impacted stones. Percutaneous trans-hepatic biliary drainage (PTBD) and surgical intervention carry morbidity and mortality. Recently endoscopic ultrasonography-guided biliary drainage has been reported as an alternative technique. Endoscopic ultrasonography-guided biliary drainage using either direct access or a rendezvous technique has attracted attention as an alternative procedure to PTBD, with a technical success between 75%-100% and with low complication rate. We have reviewed published data on EUS guided biliary drainage procedures with the aim of summarizing the efficacy and safety of this promising method.

Interventional endoscopic ultrasonography for pancreatic cancer.

Endoscopic ultrasonography (EUS) represents the combination of endoscopy and intraluminal ultrasonography. This allows use of a high-frequency transducer (5-20 MHz) that, due to the short distance to the target lesion, provides ultrasonographic images of higher resolution than those obtained from other imaging modalities, including multiple-detector-row-computed tomography, magnetic resonance imaging, and positron emission tomography. EUS is now a widely accepted modality for diagnosing pancreatic diseases. However, the most important limitation of EUS has been the lack of specificity in differentiating between benign and malignant changes. In 1992, EUS-guided fine needle aspiration (FNA) of lesions in the pancreas head was introduced into clinical practice, using a curved linear-array echoendoscope. Since then, EUS has evolved from EUS imaging to EUS-FNA and wider applications. Interventional EUS for pancreatic cancer includes EUS-FNA, EUS-guided fine needle injection, EUS-guided biliary drainage and anastomosis, EUS-guided celiac neurolysis, radiofrequency ablation, brachytherapy, and delivery of a growing number of anti-tumor agents. This review focuses on interventional EUS, including EUS-FNA and therapeutic EUS for pancreatic cancer.