Does endoscopic ultrasound-guided biliary drainage really have clinical impact?

The well established, gold standard method for treatment of obstructive jaundice involves biliary drainage under endoscopic retrograde cholangiopancreatography(ERCP) performed by pancreatobiliary endoscopists. Recently, interventions using endoscopic ultrasound(EUS) have been developed not only for obtaining cytological and histological diagnosis, but also for biliary drainage as alternative method. EUS-guided biliary drainage(EUSBD) was first reported by Giovannini et al. EUS-BD broadly includes EUS-guided rendezvous technique, EUS-guided choledochoduodenostomy, and EUS-guided hepaticogastrostomy. More recently, EUS-guided antegrade stenting and EUS-guided gallbladder drainage have also been reported. many case reports, series, and retrospective studies on EUS-BD have been reported. However, because prospective studies and comparisons between the different biliary drainage methods have not been reported, the technical success, functional success, adverse events, and stent patency with long-term follow up of EUS-BD are still unclear. Therefore, prospective, randomized controlled studies addressing these issues are needed. Despite this, EUSBD undoubtedly is clinically useful as an alternative biliary drainage method. EUS-BD has the potential to be a first-line biliary drainage method instead of ERCP if results of clinical trials are favorable and the technique is simplified.     

New antireflux plastic stent for patients with distal malignant biliary obstruction

BACKGROUND Endoscopic biliary stenting is a well-established palliative treatment for patients with unresectable distal malignant biliary obstruction(MBO). However, the main problem with stent placement is the relatively short duration of stent patency.Although self-expanding metal stents(SEMSs) have a longer patency period than plastic stents(PSs), the higher costs limit the wide use of SEMSs. A PS with an antireflux valve is an attractive idea to prolong stent patency, but no ideal design for an antireflux PS(ARPS) has been proposed. We developed a new ARPS with a "duckbilled" valve attached to the duodenal end of the stent.AIM To compare the patency of ARPSs with that of traditional PSs(TPSs) in patients with unresectable distal MBO.METHODS We conducted a single-center, prospective, randomized, controlled, double-blind study. This study was conducted at the West China Hospital of Sichuan University. Consecutive patients with extrahepatic MBO were enrolled prospectively. Eligible patients were randomly assigned to receive either an ARPS or a TPS. Patients were followed by clinic visits or telephone interviews every 1-2 mo until stent exchange, death, or the final study follow-up in October 2018. The primary outcome was the duration of stent patency. Secondary outcomes included the rate of technical success, the rate of clinical success,adverse events, and patient survival.RESULTS Between February 2016 and December 2017, 38 patients were randomly assigned to two groups, with 19 patients in each group, to receive ARPSs or TPSs. Stent insertion was technically successful in all patients. There were no significant differences between the two groups in the rates of clinical success or the rates of early or late adverse events(P = 0.660, 1.000, and 1.000, respectively). The median duration of stent patency in the ARPS group was 285 d [interquartile range(IQR),170], which was significantly longer than that in the TPS group(median, 130 d;IQR, 90, P = 0.005). No significant difference in patient survival was noted between the two groups(P = 0.900).CONCLUSION The new ARPS is safe and effective for the palliation of unresectable distal MBO,and has a significantly longer stent patency than a TPS.     

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.     

Lumen-apposing metal stent deployment for walled-off necrosis using semi-free hand technique from the intestine

Lumen-apposing metal stent (LAMS) deployment under en- doscopic ultrasonography (EUS) guidance has been used for walled-off necrosis (WON) [1] . Recently, LAMS with electrocautery enhanced delivery system has been developed. One of the advan- tages of this stent is that the stent can be delivered without any dilation devices. However, to prevent stent migration into the in- testinal lumen, it is important that stent delivery system should be inserted within the WON. When the diameter of WON is not large enough to insert stent delivery system, contralateral wall of WON may be injured. To prevent this adverse event, guidewire insertion may be useful after puncturing. In addition, according to the re- cent reports [2–4] , EUS-guided LAMS placement for WON drainage has been performed. We herein described a case of LAMS deploy- ment from the second part of the duodenum using semi-free hand technique.     

Endoscopic ultrasonography guided biliary drainage: Summary of consortium meeting,May 7^th , 2011, Chicago

Endoscopic retrograde cholangiopancreatography (ERCP) has become the preferred procedure for biliary or pancreatic drainage in various pancreatico-biliary disorders. With a success rate of more than 90%, ERCP may not achieve biliary or pancreatic drainage in cases with altered anatomy or with tumors obstructing access to the duodenum. In the past those failures were typically managed exclusively by percutaneous approaches by interventional radiologists or surgical intervention. The morbidity associated was significant especially in those patients with advanced malignancy, seeking minimally invasive interventions and improved quality of life. With the advent of biliary drainage via endoscopic ultrasound (EUS) guidance, EUS guided biliary drainage has been used more frequently within the last decade in different countries. As with any novel advanced endoscopic procedure that encompasses various approaches, advanced endoscopists all over the world have innovated and adopted diverse EUS guided biliary and pancreatic drainage techniques. This diversity has resulted in variations and improvements in EUS Guided biliary and pancreatic drainage; and over the years has led to an extensive nomenclature. The diversity of techniques, nomenclature and recent progress in our intrumentation has led to a dedicated meeting on May 7 th , 2011 during Digestive Disease Week 2011. More than 40 advanced endoscopists from United States, Brazil, Mexico, Venezuela, Colombia, Italy, France, Austria, Germany, Spain, Japan, China, South Korea and India attended this pivotal meeting. The meeting covered improved EUS guided biliary access and drainage procedures, terminology, nomenclature, training and credentialing; as well as emerging devices for EUS guided biliary drainage. This paper summarizes the meeting’s agenda and the conclusions generated by the creation of this consortium group.     

Endoscopic ultrasonography: Transition towards the future of gastro-intestinal diseases

Endoscopic ultrasonography(EUS) is a technique with an established role in the diagnosis and staging of gastro-intestinal tumors. In recent years, the spread of new devices dedicated to tissue sampling has improved the diagnostic accuracy of EUS fine-needle aspiration. The development of EUS-guided drainage of the biliopancreatic region and abdominal fluid collections has allowed EUS to evolve into an interventional tool that can replace more invasive procedures. Emerging techniques applying EUS in pancreatic cancer treatment and in celiac neurolysis have been described. Recently, confocal laser endomicroscopy has been applied to EUS as a promising technique for the in vivo histological diagnosis of gastro-intestinal, bilio-pancreatic and lymph node lesions. In this state-of-the-art review, we report the most recent data from the literature regarding EUS devices, interventional EUS, EUS-guided confocal laser endomicroscopy and EUS pancreatic cancer treatment, and we also provide an overview of their principles, clinical applications and limitations.     

A pilot proof-of-concept study of a modified device for one-step endoscopic ultrasound-guided biliary drainage in a new experimental biliary dilatation animal model

AIM:To evaluate the technical feasibility of a modified tapered metal tip and low profile introducer for onestep endoscopic ultrasound(EUS)-guided biliary drainage(EUS-BD)in a new experimental biliary dilatation porcine model.METHODS:A novel dedicated device for one-step EUS-guided biliary drainage system(DEUS)introducer has size 3F tapered catheter with size 4F metal tip for simple puncture of the intestinal wall and liver parenchyma without graded dilation.A self-expandable metal stent,consisting of both uncovered and nitinol-covered portions,was preloaded into DEUS introducer.After establishment of a biliary dilatation model using endoscopic hemoclips or band ligation with argon plasma coagulation in 9 mini-pigs,EUS-BD using a DEUS was performed following 19-G needle puncture without the use of fistula dilation devices.RESULTS:One-step EUS-BD was technically successful in seven pigs[7/9(77.8%)as intention to treat]without the aid of devices for fistula dilation from the high body of stomach or far distal esophagus to the intrahepatic(n=2)or common hepatic(n=5)duct.Primary technical failure occurred in two cases that did not show adequate biliary dilatation.In seven pigs with a successful bile duct dilatation,the technical success rate was 100%(7/7 as per protocol).Median procedure time from confirmation of the dilated bile duct to successful placement of a metallic stent was 10 min(IQR;8.9-18.1).There were no immediate procedure-related complications.CONCLUSION:Modified tapered metal tip and low profile introducer may be technically feasible for onestep EUS-BD in experimental porcine model.     

Endoscopic ultrasound-guided biliary drainage as an alternative to percutaneous drainage and surgical bypass

Endoscopic retrograde cholangiopancreatography had been a treatment modality of choice for both benign and malignant biliary tract obstruction for more than half century, with a very high clinical success rate and low complications. But in certain circumstances, such as advanced and locally advanced pancreatobiliary malignancies(pancreatic cancer, cholangiocarcinoma, ampullary tumor) and tight benign strictures, endoscopic retrograde cholangiopancreatography(ERCP) fails. Up to this point, the only alternative interventions for these conditions were percutaneous transhepatic biliary drainage or surgery. Endoscopic ultrasound guided interventions was introduced for a couple decades with the better visualization and achievement of the pancreatobiliary tract. And it’s still in the process of ongoing development. The inventions of new techniques and accessories lead to more feasibility of high-ended procedures. Endoscopic ultrasound guided biliary drainage was a novel treatment modality for the patient who failed ERCP with the less invasive technique comparing to surgical bypass. The technical and clinical success was high with acceptable complications. Regarded the ability to drain the biliary tract internally without an exploratory laparotomy, this treatment modality became a very interesting procedures for many endosonographers, worldwide, in a short period. We have reviewed the literature and suggest that endoscopic ultrasoundguided biliary drainage is also an option, and one with a high probability of success, for biliary drainage in the patients who failed conventional endoscopic drainage.     

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 peripapillary 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.     

Clinical utility of treatment method conversion during single-session endoscopic ultrasound-guided biliary drainage

BACKGROUND Although several techniques for endoscopic ultrasound-guided biliary drainage(EUS-BD)are available at present,an optimal treatment algorithm of EUS-BD has not yet been established.AIM To evaluate the clinical utility of treatment method conversion during single endoscopic sessions for difficult cases in initially planned EUS-BD.METHODS This was a single-center retrospective analysis using a prospectively accumulated database.Patients with biliary obstruction undergoing EUS-BD between May 2008 and April 2016 were included.The primary outcome was to evaluate the improvement in EUS-BD success rates by converting the treatment methods during a single endoscopic session.Secondary outcomes were clarification of the factors leading to the conversion from the initial EUS-BD and the assessment of efficacy and safety of the conversion as judged by technical success,clinical success,and adverse events(AEs).RESULTS A total of 208 patients underwent EUS-BD during the study period.For 18.8%(39/208)of the patients,the treatment methods were converted to another EUSBD technique from the initial plan.Biliary obstruction was caused by pancreatobiliary malignancies,other malignant lesions,biliary stones,and other benign lesions in 22,11,4,and 2 patients,respectively.The reasons for the difficulty with the initial EUS-BD were classified into the following 3 procedures:Target puncture(n=13),guidewire manipulation(n=18),and puncture tract dilation(n=8).Technical success was achieved in 97.4%(38/39)of the cases and clinical success was achieved in 89.5%of patients(34/38).AEs occurred in 10.3%of patients,including bile leakage(n=2),bleeding(n=1),and cholecystitis(n=1).The puncture target and drainage technique were altered in subsequent EUSBD procedures in 25 and 14 patients,respectively.The final technical success rate with 95%CI for all 208 cases was 97.1%(95%CI:93.8%-98.9%),while that of the initially planned EUS-BD was 78.8%(95%CI:72.6%-84.2%).CONCLUSION Among multi-step procedures in EUS-BD,guidewire manipulation appeared to be the most technically challenging.When initially planned EUS-BD is technically difficult,treatment method conversion in a single endoscopic session may result in successful EUS-BD without leading to severe AEs.     

Use of fully covered self-expanding metal stents in benign biliary diseases

Biliary fully covered self-expanding metal stents (FCSEMS) are now being used to treat several benign biliary conditions. Advantages include small predeployment and large postexpansion diameters in addition to an easy insertion technique. Lack of imbedding of the metal into the bile duct wall enables removability. In benign biliary strictures that usually require multiple procedures, despite the substantially higher cost of FCSEMS compared with plastic stents, the use of FCSEMS is offset by the reduced number of endoscopic retrograde cholangiopancreatography interventions required to achieve stricture resolution. In the same way, FCSEMS have also been employed to treat complex bile leaks, perforation and bleeding after endoscopic biliary sphincterotomy and as an aid to maintain permanent drainage tracts obtained by means of Endoscopic Ultrasound-guided biliary drainage. Good success rates have been achieved in all these conditions with an acceptable number of complications. FCSEMS were successfully removed in all patients. Comparative studies of FCSEMS and plastic stents are needed to demonstrate effi cacy and cost-effectiveness     

Endoscopic ultrasound guided drainage of pancreatic fluid collections: Assessment of the procedure,technical details and review of the literature

Endoscopic ultrasound(EUS) guided drainage of pancreatic fluid collections(PFC) has become increasingly popular and become first line management option in many centers. Use of therapeutic echoendoscopes has greatly increased the applicability of EUS guided transmural drainage. Drainage is indicated in symptomatic PFCs, PFC related infection, bleed, luminal obstruction, fistulization and biliary obstruction. EUS guided transmural drainage of PFCs is preferred in patients with non bulging lesions, portal hypertension, bleeding tendency and in those whom conventional drainage has failed. In the present decade significant progress has been made in minimally invasive endoscopic techniques. There are newer stent designs, access devices and techniques for more efficient drainage of PFCs. In this review, we discuss the EUS guided drainage of PFCs in acute pancreatitis.     

Clinical outcomes of endoscopic management of pancreatic fluid collections in cirrhotics vs non-cirrhotics: A comparative study

BACKGROUND Endoscopic management of symptomatic pancreatic fluid collections(PFCs)using self-expandable metal stents(SEMS) placement has emerged as an innovative therapeutic approach with excellent efficacy, safety, and relatively few adverse outcomes. However, their use has not been studied in patients with cirrhosis. Cirrhotics tend to be considered less than optimal candidates due to concern for portal hypertension and coagulopathy related complications.AIM To compare the efficacy and safety of using SEMS for drainage of symptomatic PFCs in cirrhotic vs non-cirrhotic patients.METHODS We conducted a retrospective comparative analysis of patients with symptomatic PFCs [pancreatic pseudocyst(PP) or walled-off necrosis(WON)] who underwent endoscopic ultrasound(EUS)-guided placement of fully covered self-expandable metals stents or lumen-apposing self-expandable metal stents. All patients were followed clinically until resolution of PFCs or death. Definition:(1) Technical success was defined as successful placement of SEMS; and(2) Clinical success was defined as complete resolution of the PFCs without additional interventions including interventional radiology or surgery. Number of procedures performed per patient, number of patients who achieved complete resolution of the PFCs without additional interventions and procedure related adverse events were recorded.RESULTS From January 2012 to December 2017, a total of 88 patients underwent EUS-guided drainage of symptomatic PFCs. Of these, 58 non cirrhotic patients underwent plastic stent insertion for management of PFC and 30 patients, 5 with cirrhosis and 25 without cirrhosis, underwent EUS-guided transmural drainage with SEMS, including 18(60%) PP and 12(40%) WON. Technical success was achieved in all 30 patients. Clinical success was achieved in 60% cirrhotic patients and 92% non-cirrhotics(P = 0.12). Procedure-related adverse events were 60% in cirrhotic and 28% non-cirrhotic(P = 0.62). Moreover, fatal adverse events were statistically more common in cirrhotics compared with non-cirrhotics(0 vs 40%; P= 0.023). Successful stent removal following resolution of the PFC, was 60% in cirrhotics and 80% in non-cirrhotics(P = 0.57). Post-procedure length of hospitalization was 18.6 ± 20.3 d in cirrhotics and 5.6 ± 13.7 d in non-cirrhotics(P= 0.084).CONCLUSION EUS-guided management of PFC using SEMS placement has a high technical and clinical success rate in non-cirrhotics. However, in cirrhotics caution must be exercised given the high morbidity and mortality as evidenced by our cohort,particularly for the endoscopic debridement of WONs. Larger, multicenter studies are warranted to further characterize the risk profile and outcomes in these patients.     

Applications of endoscopic ultrasound in pancreatic cancer

Since the introduction of endoscopic ultrasound guided fine-needle aspiration(EUS-FNA),EUS has assumed a growing role in the diagnosis and management of pancreatic ductal adenocarcinoma(PDAC).The objective of this review is to discuss the various applications of EUS and EUS-FNA in PDAC.Initially,its use for detection,diagnosis and staging will be described.EUS and EUS-FNA are highly accurate modalities for detection and diagnosis of PDAC,this high accuracy,however,is decreased in specific situations particularly in the presence of chronic pancreatitis.Novel techniques such as contrast-enhanced EUS,elastography and analysis of DNA markers such as k-ras mutation analysis in FNA samples are in progress and might improve the accuracy of EUS in the detection of PDAC in this setting and will be addressed.EUS and EUS-FNA have recently evolved from a diagnostic to a therapeutic technique in the management of PDAC.Significant developments in therapeutic EUS have occurred including advances in celiac plexus interventions with direct injection of ganglia and improved pain control,EUS-guided fiducial and brachytherapy seed placement,fine-needle injection of intra-tumoral agents and advances in EUS-guided biliary drainage.The future role of EUS and EUS in management of PDAC is still emerging.     

Tumors and new endoscopic ultrasound-guided therapies

With the advent of linear echoendoscopes, endoscopic ultrasound (EUS) has become more operative and a new field of oncological application has been opened up. From tumor staging to tissue acquisition under EUS-guided fine-needle aspiration, new operative procedures have been developed on the principle of the EUS-guided puncture. A hybrid probe combining radiofrequency with cryotechnology is now available, to be passed through the operative channel of the echoendoscope into the tumor to create an area of ablation. EUS-guided fine-needle injection is emerging as a method to deliver anti-tumoral agents inside the tumor. Ethanol lavage, with or without paclitaxel, has been proposed for the treatment of cystic tumors in non-resectable cases and complete resolution has been recorded in up to 70%-80%. Many other chemical or biological agents have been investigated for the treatment of pancreatic adenocarcinoma: activated allogenic lymphocyte culture (Cytoimplant), a replication-deficient adenovirus vector carrying the tumor necrosis factor-α gene, or an oncolytic attenuated adenovirus (ONYX-015). The potential advantage of treatment under EUS control is the real-time imaging guidance into a deep target likethe pancreas which is extremely difficult to reach by a percutaneous approach. To date there are no randomized controlled trials to confirm the real clinical benefits of these treatments compared to standard therapy so it seems wise to reserve them only for experimental protocols approved by ethics committees.     

Advances in endoscopic ultrasound imaging of colorectal diseases

The development of endoscopic ultrasound(EUS) has had a significant impact for patients with digestive diseases, enabling enhanced diagnostic and therapeutic procedures, with most of the available evidence focusing on upper gastrointestinal(GI) and pancreaticobiliary diseases. For the lower GI tract the main application of EUS has been in staging rectal cancer, as a complementary technique to other cross-sectional imaging methods. EUS can provide highly accurate indepth assessments of tumour infiltration, performing best in the diagnosis of early rectal tumours. In the light of recent developments other EUS applications for colorectal diseases have been also envisaged and are currently under investigation, including beyond-rectum tumour staging by means of the newly developed forward-viewing radial array echoendoscope. Due to its high resolution, EUS might be also regarded as an ideal method for the evaluation of subepithelial lesions. Their differential diagnosis is possible by imaging the originating wall layer and the associated echostructure, and cytological and histological confirmation can be obtained through EUS-guided fine needle aspiration or trucut biopsy. However, reports on the use of EUS in colorectal subepithelial lesions are currently limited. EUS allows detailed examination of perirectal and perianal complications in Crohn’s disease and, as a safe and less expensive investigation, can be used to monitor therapeutic response of fistulae, which seems to improve outcomes and reduce the need for additional surgery. Furthermore, EUS image enhancement techniques, such as the use of contrast agents or elastography, have recently been evaluated for colorectal indications as well. Possible applications of contrast enhancement include the assessment of tumour angiogenesis in colorectal cancer, the monitoring of disease activity in inflammatory bowel disease based on quantification of bowel wall vascularization, and differentiating between benign and malignant subepithelial tumours. Recent reports suggest that EUS elastography enables highly accurate discrimination of colorectal adenocarcinomas from adenomas, while inflammatory bowel disease phenotypes can be distinguished based on the strain ratio calculation. Among EUS-guided therapies, the drainage of abdominal and pelvic collections has been regarded as a safe and effective procedure to be used as an alternative for the transcutaneous route, while the placing of fiducial markers under EUS guidance for targeted radiotherapy in rectal cancer or the use of contrast microbubbles as drug-delivery vehicles represent experimental therapeutic applications that could greatly impact the forthcoming management of patients with colorectal diseases, pending on further investigations.     

Current surgical treatment for bile duct cancer

Since extrahepatic bile duct cancer is difficult to diagnose and to cure,a safe and radical surgical strategy is needed.In this review,the modes of infiltration and spread of extrahepatic bile duct cancer and surgical strategy are discussed.Extended hemihepatectomy,with or without pancreatoduodenectomy(PD),plus extrahepatic bile duct resection and regional lymphadenectomy has recently been recognized as the standard curative treatment for hilar bile duct cancer.On the other hand,PD is the choice of treatment for middle and distal bile duct cancer.Major hepatectomy concomitant with PD(hepatopancreatoduodenectomy)has been applied to selected patients with widespread tumors.Preoperative biliary drainage(BD)followed by portal vein embolization(PVE)enables major hepatectomy in patients with hilar bile duct cancer without mortality.BD should be performed considering the surgical procedure,especially,in patients with separated intrahepatic bile ducts caused by hilar bile duct cancer.Right or left trisectoriectomy are indicated according to the tumor spread and biliary anatomy.As a result,extended radical resection offers a chance for cure of hilar bile duct cancer with improved resectability,curability,and a 5-year survival rate of 40%.A 5-year survival rate has ranged from 24% to 39% after PD for middle and distal bile duct cancer.     

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.     

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".     

Current status of endoscopic retrograde cholangiopancreatography in patients with surgically altered anatomy

Endoscopic retrograde cholangiopancreatography(ERCP)in patients with surgically altered anatomy must be performed by a highly experienced endoscopist.The challenges are accessing the afferent limb in different types of reconstruction,cannulating a papilla with a reverse orientation,and performing therapeutic interventions with uncommon endoscopic accessories.The development of endoscopic techniques has led to higher success rates in this group of patients.Device-assisted ERCP is the endoscopic procedure of choice for high success rates in short-limb reconstruction;however,these success rate is lower in long-limb reconstruction.ERCP assisted by endoscopic ultrasonography is now popular because it can be performed independent of the limb length;however,it must be performed by a highly experienced and skilled endoscopist.Stent deployment and small stone removal can be performed immediately after ERCP assisted by endoscopic ultrasonography,but the second session is needed for other difficult procedures such as cholangioscopy-guided electrohydraulic lithotripsy.Laparoscopic-assisted ERCP has an almost 100%success rate in longlimb reconstruction because of the use of a conventional side-view duodenoscope,which is compatible with standard accessories.This requires cooperation between the surgeon and endoscopist and is suitable in urgent situations requiring concomitant cholecystectomy.This review focuses on the advantages,disadvantages,and outcomes of various procedures that are suitable in different situations and reconstruction types.Emerging new techniques and their outcomes are also discussed.