Endoscopic ultrasonography for surveillance of individuals at high risk for pancreatic cancer

Pancreatic cancer is a highly lethal disease with a ge-netic susceptibility and familial aggregation found in 3%-16% of patients. Early diagnosis remains the only hope for curative treatment and improvement of prog-nosis. This can be reached by the implementation of an intensive screening program, actually recommended for individuals at high-risk for pancreatic cancer de-velopment. The aim of this strategy is to identify pre-malignant precursors or asymptomatic pancreatic can-cer lesions, curable by surgery. Endoscopic ultrasound (EUS) with or without fine needle aspiration(FNA) seems to be the most promising technique for early de-tection of pancreatic cancer. It has been described as a highly sensitive and accurate tool, especially for small and cystic lesions. Pancreatic intraepithelial neoplasia, a precursor lesion which is highly represented in high-risk individuals, seems to have characteristics chronic pancreatitis-like changes well detected by EUS. Many screening protocols have demonstrated high diagnostic yields for pancreatic pre-malignant lesions, allowing prophylactic pancreatectomies. However, it shows a high interobserver variety even among experienced en-dosonographers and a low sensitivity in case of chronic pancreatitis. Some new techniques such as contrast-en-hanced harmonic EUS, computer-aided diagnostic tech-niques, confocal laser endomicroscopy miniprobe andthe detection of DNA abnormalities or protein markersby FNA, promise improvement of the diagnostic yield ofEUS. As the resolution of imaging improves and as ourknowledge of precursor lesions grows, we believe thatEUS could become the most suitable method to detectcurable pancreatic neoplasms in correctly identifiedasymptomatic at-risk patients.     

Endoscopic ultrasound guided tumor directed therapy and cyst ablation

Endoscopic ultrasonography (EUS) has become an interventional procedure for the diagnosis and treatment of various gastrointestinal and pancreatic tumors. Because of the unique anatomical location of the pancreas, EUS-guided therapies offer substantial promise for the delivery of targeted treatments. This article reviews the recent EUS-guided various therapeutic methods for pancreatic cyst and tumor ablation, especially focusing on cystic neoplasms.     

Possibilities of interventional endoscopic ultrasound

Since endoscopic ultrasound (EUS) was developed in the 1990s, EUS has become widely accepted as an imaging tool. EUS is categorized into radial and linear in design. Radial endoscopes provide cross-sectional imaging of the mediastinum, gastrointestinal tract, liver, spleen, kidney, adrenal gland, and pancreas, which has highly accuracy in the T and N staging of esophageal, lung, gastric, rectal, and pancreatic cancer. Tumor staging is common indication of radial-EUS, and EUSstaging is predictive of surgical resectability. In contrast, linear array endoscope uses a side-viewing probe and has advantages in the ability to perform EUSguides fine needle aspiration (EUS-FNA), which has been established for cytologic diagnosis. For example, EUS-FNA arrows accurate nodal staging of esophageal cancer before surgery, which provides more accurate assessment of nodes than radial-EUS imaging alone. EUS-FNA has been also commonly used for diagnose of pancreatic diseases because of the highly accuracy than US or computed tomography. EUS and EUS-FNA has been used not only for TNM staging and cytologic diagnosis of pancreatic cancer, but also for evaluation of chronic pancreatitis, pancreatic cystic lesions, and other pancreatic masses. More recently, EUS-FNA has developed into EUS-guided fine needle injection including EUS-guided celiac plexus neurolysis, celiac plexus block, and other "interventional EUS" procedures. In this review, we have summarized the new possibilities offered by "interventional EUS".     

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 EUSguided 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 ECLAMS 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.     

Cystic pancreatic lesions,the endless dilemma

Cystic pancreatic lesions involve a wide variety of pathological entities that include neoplastic and non-neoplastic lesions. The proper diagnosis, differentiation, and staging of these cystic lesions are considered a crucial issue in planning further management. There are great challenges for their diagnostic models. In our time, new emerging methods for this diagnosis have been discovered. Endoscopic ultrasonography-guided fine-needle aspiration cytology with chemical and molecular analysis of cyst fluid and EUS-guided fine needle-based confocal laser endomicroscopy, through the needle microforceps biopsy, and single-operator cholangioscopy/pancreatoscopy are promising methods that have been used in the diagnosis of cystic pancreatic lesions. Hereby we discuss the diagnosis of cystic pancreatic lesions and the benefits of various diagnostic models.     

Current role of endoscopic ultrasound in the diagnosis and management of pancreatic cancer

Endoscopic ultrasound (EUS) has emerged as an invaluable tool for the diagnosis, staging and treatment of pancreatic ductal adenocarcinoma (PDAC). EUS is currently the most sensitive imaging tool for the detection of solid pancreatic tumors. Conventional EUS has evolved, and new imaging techniques, such as contrast-enhanced harmonics and elastography, have been developed to improve diagnostic accuracy during the evaluation of focal pancreatic lesions. More recently, evaluation with artificial intelligence has shown promising results to overcome operator-related flaws during EUS imaging evaluation. Currently, an appropriate diagnosis is based on a proper histological assessment, and EUS-guided tissue acquisition is the standard procedure for pancreatic sampling. Newly developed cutting needles with core tissue procurement provide the possibility of molecular evaluation for personalized oncological treatment. Interventional EUS has modified the therapeutic approach, primarily for advanced pancreatic cancer. EUS-guided fiducial placement for local targeted radiotherapy treatment or EUS-guided radiofrequency ablation has been developed for local treatment, especially for patients with pancreatic cancer not suitable for surgical resection. Additionally, EUS-guided therapeutic procedures, such as celiac plexus neurolysis for pain control and EUS-guided biliary drainage for biliary obstruction, have dramatically improved in recent years toward a more effective and less invasive procedure to palliate complications related to PDAC. All the current benefits of EUS in the diagnosis and management of PDAC will be thoroughly discussed.     

Technical tips of endoscopic ultrasound-guided choledochoduodenostomy

Endoscopic ultrasound(EUS) is clinically useful not only as a diagnostic tool during EUS-guided fine needle aspiration,but also during interventional EUS.EUS-guided biliary drainage has been developed and performed by experienced endoscopists.EUS-guided choledocoduodenostomy(EUS-CDS) is relatively well established as an alternative biliary drainage method for biliary decompression in patients with biliary obstruction.The reported technical success rate of EUS-CDS ranges from 50% to 100%,and the clinical success rate ranges from 92% to 100%.Further,the over-all technicalsuccess rate was 93%,and clinical success rate was 98%.Based on the currently available literature,the overall adverse event rate for EUS-CDS is 16%.The data on the cumulative technical and clinical success rate for EUS-CDS is promising.However,EUS-CDS can still lead to several problems,so techniques or devices that are more feasible and safe need to be established.EUS-CDS has the potential to become a first-line biliary drainage procedure,although standardizing the technique in multicenter clinical trials and comparisons with endoscopic biliary drainage by randomized clinical trials are still needed.     

Endoscopic diagnosis of cystic lesions of the pancreas

Endoscopic methods are increasingly used in the diagnosis of cystic lesions of the pancreas. The two major endoscopic approaches are endoscopic ultrasonography (EUS) and transpapillary diagnosis. EUS‐guided fine‐needle aspiration cytology and EUS‐guided fine needle‐based confocal laser endomicroscopy have been used in the differential diagnosis of mucinous and non‐mucinous pancreatic cysts. EUS is the most sensitive modality for detecting mural nodules (MN) in intraductal papillary mucinous neoplasms (IPMN). Contrast‐enhanced harmonic EUS (CH‐EUS), as an add‐on to EUS, is useful for identifying and characterizing MN. Recent studies show that CH‐EUS has a sensitivity of 60–100% and a specificity of 75–92.9% for diagnosing malignant cysts. Intraductal ultrasonography and peroral pancreatoscopy are especially useful for detecting MN and IPMN. A recent meta‐analysis showed that cytological assessment of pancreatic juice using a transpapillary approach had a pooled sensitivity, specificity, and accuracy of 35.1%, 97.2%, and 92.9%, respectively, for diagnosing malignant IPMN. Further studies are warranted to determine the indications for each of these novel techniques in assessing cystic lesions of the pancreas.     

Interventional endoscopic ultrasound in pancreatic diseases.

During the last 15 years, endoscopic ultrasound (EUS) has become an important imaging procedure for diagnosis and management of pancreatic diseases. The clinical interest of EUS is now enhanced by interventional procedures. Noteworthy, fine-needle aspiration biopsy is one of the most important contributions of EUS, in particular for the investigation of patients with pancreatic cancer and cystic tumors. EUS-guided fine-needle aspiration appears to be a safe and reliable technique to obtain tissue from pancreatic masses with a low risk of complications. EUS became also a therapeutic procedure, especially applied for celiac plexus neurolysis, pseudocyst drainage, and pancreaticogastrostomy. Further developments are expected by improvement of needle devices such as pancreatic pseudocyst drainage kits. In the future, EUS might be also a support for local application of new treatments of pancreatic tumors, such as gene or cellular therapy products. In this review, we discuss the current clinical applications of interventional EUS and the future development for diagnosis and management of pancreatic diseases.     

Endoscopic ultrasound in the diagnosis and treatment of pancreatic disease

Endoscopic ultrasound(EUS)is an important part of modern gastrointestinal endoscopy and now has an integral role in the diagnostic evaluation of pancreatic diseases.Furthermore,as EUS technology has advanced,it has increasingly become a therapeutic procedure,and the prospect of multiple applications of interventional EUS for the pancreas is truly on the near horizon.However,this review focuses on the established diagnostic and therapeutic roles of EUS that are used in current clinical practice.In particular,the diagnostic evaluation of acute pancreatitis,chronic pancreatitis,cystic pancreatic lesions and solid masses of the pancreas are discussed.The newer enhanced imaging modalities of elastography and contrast enhancement are evaluated in this context.The main therapeutic aspects of pancreatic EUS are then considered,namely celiac plexus block and celiac plexus neurolysis for pain control in chronic pancreatitis and pancreas cancer,and EUS-guided drainage of pancreatic fluid collections.     

Endoscopic ultrasound-guided interventions in special situations

Endoscopic ultrasound(EUS) was introduced in 1982 and has since become a popular advanced procedure for diagnosis and therapeutic intervention. Initially, EUS was most commonly used for the diagnosis of pancreatobiliary diseases and tissue acquisition. EUS was first used for guided cholangiography in 1996, followed by EUS-guided biliary drainage in 2001. Advancements in equipment and endoscopic accessories have led to an expansion of EUS-guided procedures, which now include EUS-guided drainage of intra-abdominal abscesses or collections, intravascular treatment of refractory variceal and nonvariceal bleeding, transmural pancreatic drainage, common bile duct stone clearance, enteral feeding tube placement and entero-enteric anastomosis. Patients with surgically altered upper gastrointestinal anatomies have greatly benefited from EUS also. This systematic review describes and discusses EUS procedures performed in uncommon diseases and conditions, as well as applications on more vulnerable patients such as young children and pregnant women. In these cases, routine approaches do not always apply, and thus may require the use of innovative and unconventional techniques. Increased knowledge of such special applications will help increase the success rates of these procedures and provide a foundation for additional advances and utilizations of the technique.     

Últimos avances sobre los tumores pancreáticos

Pancreatic cancer (PC) continues to have a very poor prognosis. New epidemiological trials suggest that statins could play a protective role in smokers, while HbsAg-positive hepatitis B virus could be a risk factor. Endoscopic ultrasound (EUS) is the main diagnostic tool for PC, and new technologies associated with this technique have emerged, such as quantitative elastography, intravenous contrasts or, more recently, LASER confocal endomicroscopy. New markers in urine or pancreatic juice have appeared to distinguish between PC and chronic pancreatitis. The role of the “on site” cytopathologist to increase the diagnostic yield of EUS-guided pancreatic sampling is completely supported by new prospective trials and some multicenter studies have been reported that compare the standard cytologic needles with the new procore-histology needles. Regarding cystic pancreatic tumors, most studies have aimed to validate the 2012 Sendai international guidelines and to ascertain predictive factors of malignancy in cystic lesions, mainly intraductal papillary mucinous neoplasm (IPMN). The role of intracystic CEA levels in determining malignancy is challenged. From a therapeutic point of view, EUS-guided radiofrequency ablation of cystic and solid lesions has emerged as a feasible and safe procedure in specific circumstances.     

Últimos avances en tumores de páncreas

Pancreatic cancer is difficult to diagnose and treat. Prognosis is poor, since this disease is usually detected at advanced stages, when the possibilities of any treatment with curative intent are 20% or less. To improve prognosis, new screening strategies are being designed, especially with the development of a new international consensus with recommendations on the management of patients at high risk of developing pancreatic cancer.Two especially useful techniques in the diagnosis of this disease are elastography and contrast-enhanced endoscopic ultrasound (EUS). Advances have been made in EUS-guided biopsy with the development of histology needles that increase diagnostic efficacy and the quality of the samples. Finally, there have been a few advances in treatment. The role of neoadjuvant therapy in locally advanced tumors and the efficacy of distinct neurolysis strategies in pain therapy have been confirmed. Covered metallic stents seem to be the best option to treat biliary obstruction. A notable development is the development of EUS-guided confocal endomicroscopy to improve the diagnosis and follow-up of cystic tumors of the pancreas, especially intraductal papillary mucinous tumors of the lateral branch.     

Endoscopic ultrasound-guided drainage of postoperative intra-abdominal abscesses

Although endoscopic ultrasound(EUS)-guided drainage has become the standard procedure for pancreatic pseudocysts in recent years and is generally regarded as a safe and effective method,there have been few reports of EUS-guided drainage of postoperative intra-abdominal abscesses.Here we report our experience with 4 cases of postoperative intraabdominal abscesses for which EUS-guided drainage was performed between May 2011 and May 2014.Distal pancreatectomy had been performed in 3 cases,whereas low anterior resection for rectal cancer was performed in the remaining case.All patients underwent transgastric naso-cystic drainage,which resulted in clinical improvement without complications,even when performed within 4 wk after surgery.On average,the naso-cystic drain was removed 10 d after placement,with no abscess recurrence.Based on these findings,we believe that EUS-guided drainage of postoperative intraabdominal abscesses is a safe and effective method,although further large-scale investigations are required to confirm our findings.     

Appraisal of needle-based confocal laser endomicroscopy in the diagnosis of pancreatic cysts

Nearly 2.5% of cross-sectional imaging studies will report a finding of a cystic pancreatic lesion. Eventhough most of these are incidental findings, it remains very concerning for both patients and treating clinicians. Differentiating and predicting malignant transformation in pancreatic cystic lesions is clinically challenging. Current evaluation of suspicious cystic lesions includes a combination of radiologic imaging, endoscopic ultrasound(EUS) and cyst fluid analyses. Despite these attempts, precise diagnostic stratification among nonmucinous, mucinous, and malignant cystic lesions is often not possible until surgical resection. EUS-guided needle based confocal laser endomicroscopy(n CLE) for evaluation of pancreatic cysts is emerging as a powerful technique with remarkable potential. Though limited imaging data from 3 large clinical trials(INSPECT, DETECT and CONTACT) are currently the reference standard for n CLE imaging, nonetheless these have not been validated in large studies. The aim of this review article is to review the evolving role of EUS-guided n CLE in management of pancreatic cystic lesions in terms of its significance, adverse events, limitations, and implications.     

超声内镜对胰腺疾病的诊断价值

内镜超声检查(EUS)指内镜的前端装有高频超声探头,在内镜直视下探头被送入胃肠腔内,直接对胃肠道病变进行超声扫描,或透过胃肠壁对肝胆胰病变进行观察,由于超声探头离病变部位近,无腹壁衰减和消化道气体的影响,采用较高频率的超声波,可获得较清晰的图像,是近年应用于消化系统疾病诊断的新技术.由于其对胰腺实质及胰管的良好显示,现在越来越普遍地运用于胰腺疾病的诊断.EUS引导下针吸细胞学检查(EUS-FNA)作为EUS检查的重要补充手段,可以获得病理诊断,进一步提高疾病的诊断准确率.     

线阵式彩色内镜超声对食管癌的分级诊断

目的 探讨内镜超声（EUS）检查对判断肿瘤侵犯深度及淋巴结转移的效用，期望有助手术治疗。方法 选择20例胃镜诊断的食管癌患者，10例术前CT检查作T分级，20例行EUS检查并进行T分级，对其中3例淋巴结作EUS引导下细针穿刺细胞学检查。结果 10例中CT分级仅4例与手术结果吻合，EUS检查20例中17例与手术结果分期一致，分级误差主要发生在T4期上。3例淋巴结穿刺2例证实为恶性，无并发症发生。结论 EUS对食管癌T分级有较高的敏感性，EUS引导下穿刺可望进一步提高其准确性。     

Endoscopic ultrasound guided vascular access and therapy: A promising indication

Endoscopic ultrasound (EUS) is an imaging technique that has consolidated its role as an important tool for diagnosis and therapeutics. In recent years we have seen a dramatic increase in the number of EUS-guided therapeutic indications (celiac plexus neurolysis/block, pseudocyst drainage, etc). Preliminary reports have suggested EUS may also be used to guide vascular access for both imaging and treating different vascular diseases. This review aims to objectively describe the existing evidence in the field.     

Recent advances in endoscopic ultrasonography-guided biliary interventions

Interventional endoscopic ultrasonography (EUS) based on EUS-guided fine-needle aspiration has rapidly spread as a minimally invasive procedure. Especially in patients with failed endoscopic retrograde cholangiopancreatography, EUS-guided biliary intervention is reported to be useful as salvage therapy. EUS-guided biliary interventions are carried out using three techniques: EUS-guided bilioenteric anastomosis, EUS-guided rendezvous procedure, and EUS-guided antegrade treatment. Although interventional EUS is not yet a standardized procedure, there have been recent advances in this field that address various biliary diseases. Here, we summarize the indications, techniques, clinical results of previous studies, and future perspectives.     

Current status and perspective of endoscopic ultrasonography‐guided gastrojejunostomy: endoscopic ultrasonography‐guided double‐balloon‐occluded gastrojejunostomy (with videos)

Surgical intervention and, more recently, endoscopic intervention have been performed for the treatment of malignant gastric outlet obstruction. Recently, endoscopic ultrasonography (EUS)‐guided gastrojejunostomy using special devices has been established. In line with this, we have developed a novel EUS‐guided double‐balloon‐occluded gastrojejunostomy (EBOG) using a lumen‐apposing biflanged metal stent. Herein, we describe the technique and outcome of EBOG.