Greetings from the Guest Editor

The role and utility of cholangioscopy for diagnosing indeterminate biliary strictures

Abstract : Biliary strictures are considered indeterminate when evaluation with imaging and standard tissue sampling during endoscopic retrograde cholangiopancreatography (ERCP) are non-diagnostic. Standard tissue sampling techniques include cytologic brushings, with or without fluorescence in situ hybridization (FISH), and endoscopic intraductal biopsies. These strictures are often clinically suspicious for malignancy. The management of these patients can vary substantially and relies on an accurate diagnosis of the lesion. Unfortunately, despite numerous modalities, the sensitivity of existing tissue sampling techniques remains low and can lead to delays in diagnosis and the need for additional procedures. Cholangioscopy has emerged as a means to visually inspect and obtain image-guided biopsies of the lesion in question, with improved sensitivity as well as a high specificity and accuracy for diagnosing the etiology of indeterminate biliary strictures. The types of cholangioscopy systems and a summary of the pertinent literature are discussed in this review.

Lumen apposing metal stents: A review of current uses and outcomes

Abstract : Lumen-apposing metal stents (LAMS) represent a new innovation in gastrointestinal endoscopy. These devices have a saddle-shaped design and larger inner lumen diameter than either plastic or metal biliary stents, which should decrease the risk of migration and allows for an endoscope to pass into pancreatic fluid collections as well as the ability to perform direct endoscopic necrosectomy. LAMS were originally conceived and designed for transmural pancreatic fluid collection drainage but are currently also being used for many off label indications. There are three different LAMS available at this time around the globe. This manuscript will review the current state of the art with regards to LAMS and their indications, usage, and outcomes.

Novel diagnostic and therapeutic modalities using endoscopic ultrasound in pancreatic disease

Abstract : Endoscopic ultrasound is a rapidly evolving technology with an expanding list of diagnostic and therapeutic capabilities. Innovative uses of endoscopic ultrasound in pancreatic malignancy may serve to improve survivability with earlier detection and groundbreaking interventions. This article aims to review these novel techniques.

Advances in endotherapy in chronic pancreatitis

Abstract : Patients with chronic pancreatitis may develop complications such as chronic debilitating abdominal pain related to neuropathy, pancreatic duct leaks, pseudocysts, pancreatic carcinoma, pancreatic duct calcifications and strictures. Management of mechanical complications of chronic pancreatitis may pose a significant challenge to the interventional endoscopist. The purpose of this manuscript is to explore the latest developments in interventional techniques and to set the stage for future investigations.

An appraisal of pancreatic cyst fluid molecular markers

Abstract : Pancreatic malignancy is the third leading cause of cancer related death in the United States with limited viable screening options. By the end of this decade, cancers are poised to become the leading cause of death with pancreatic cancer projected to be the second leading cause of cancer related mortality. Pancreatic cystic lesions (PCLs) are found in approximately 5%–14% of patients due to the increased utilization of cross-sectional imaging, with approximately 8%–10% of pancreatic cancers originating as PCLs. Current screening guidelines have shown discrepancies between morphologic characteristics of PCLs and identifying advanced pancreatic disease. Molecular analysis has emerged as a novel technology to aid in adequate diagnosis and management decisions of PCLs. Mucinous cysts including intraductal papillary mucinous neoplasms (IPMNs) or mucinous cystic neoplasms have similar oncogenic mutations including KRAS, TP53, SMAD4, PIK3CA, PTEN, or CKDN2A, while GNAS and RNF43 mutations are specific only to IPMNs. Serous cystadenomas have been associated with a loss of tumor suppressor gene VHL, while solid-psuedopapillary neoplasms have an oncogenic mutation CTNNB1. A specific molecular marker to diagnose existing high-grade dysplasia or impending malignant transformation is yet to be identified. Moving forward it is important to advance technology in isolating and identifying high-risk molecular markers from cyst fluid while considering their increased utilization in the evaluation of PCLs.

Endoscopic retrograde cholangiopancreatography complications: Techniques to reduce risk and management strategies

Abstract : Adverse events after endoscopic retrograde cholangiopancreatography (ERCP) are not uncommon and can be associated with tragic outcomes. Bleeding, perforation, and post-ERCP pancreatitis are the most common complications. Some events are unavoidable; others are associated with well described risk factors so that they can be either anticipated and/or measures can be taken for prevention or at least risk reduction. This review will focus on the more common complications after ERCP, their risk factors, and potential strategies for risk reduction. Additionally, recommendations for management of ERCP complications will be presented.

Endoscopic management of postoperative fistulas and leaks

Abstract : Postoperative complications from gastrointestinal surgery can be associated with significant morbidity, and mortality especially if repeat surgery is needed to address these complications. There are wide array of endoscopic interventions and tools available for management of these complications using minimally invasive methods thus decreasing length of hospitalization, morbidity and leading to better patient outcomes. With the advent new tools like Overstitch device, Over the Scope Clip, fibrin glue, etc., these complications can be managed successfully with minimal morbidity. We provide an indepth discussion about available endoscopic options and their application in various scenarios in our article. Endoscopist should be familiar with these complications and endoscopic tools to promote use of these tools and techniques to achieve successful management of these complex conditions.

Recent developments in endoscopic ultrasound-guided diagnosis and therapy of pancreatic cystic neoplasms

Abstract : This review highlights new developments in the field of endoscopic ultrasound (EUS)-guided diagnosis and therapy of pancreatic cystic neoplasms. Studies pertinent to pancreatic cyst diagnosis by morphology, namely diagnostic accuracies of various criteria such as pancreatic cyst size, pancreatic duct size, mural nodules and use of EUS contrast agent are discussed. Tissue acquisition during EUS using a novel brush for cytology as well as microforceps is explored further. The role of multiple emerging molecular markers such as CEA, BRAF, KRAS, and GNAS, to name a few, is covered in detail. Recent developments relating to the utility of micro-RNAs in the analysis of cyst fluid is explored. Needle based confocal laser endomicroscopy for pancreatic cyst imaging is a recent development, and findings from recent trials are discussed. Furthermore, recent data regarding the role of ablative therapies using alcohol, paclitaxel and radiofrequency ablation of cyst is covered. Also, given the multiplicity of guidelines regarding management of pancreatic cystic neoplasms, we discuss the merits and shortcoming of these guidelines.

Percutaneous intervention for bilioenteric anastomotic strictures: Current strategies and future directions

Abstract : Postoperative bilioenteric anastomotic strictures are encountered in a significant number of patients after primary biliary repair, hepatopancreaticobiliary tumor resection, and liver transplantation. Due to difficulties with repeat surgery and endoscopic access, percutaneous dilation has become the accepted treatment in these cases. While the overall paradigm of percutaneous access, balloon dilation, and catheter stenting remains consistent, institutional protocols differ in several technical variables including balloon sizes, inflation techniques, catheter sizing, and overall time course of treatment, amongst others. The current review aims to discuss various treatment protocols and their relative efficacy, as well as touch on emerging techniques.