Use of endoscopic ultrasound-guided gallbladder drainage as a rescue approach in cases of unsuccessful biliary drainage.

This narrative review provides an overview of the utilization of endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) as a salvage approach in cases of unsuccessful conventional management. EUS-GBD is a minimally invasive and effective technique for drainage in patients with acute cholecystitis with high risk of surgery. The procedure has demonstrated impressive technical and clinical success rates with low rates of adverse events, making it a safe and effective option for appropriate candidates. Furthermore, EUS-GBD can also serve as a rescue option for patients who have failed endoscopic retrograde cholangiopancreatography or EUS biliary drainage for relief of jaundice in malignant biliary stricture. However, patient selection is critical for the success of EUS-GBD, and proper patient selection and risk assessment are important to ensure the safety and efficacy of the procedure. As the field continues to evolve and mature, ongoing research will further refine our understanding of the benefits and limitations of EUS-GBD, ultimately leading to improved outcomes for patients.

Evolution of interventional endoscopic ultrasound.

Endoscopic ultrasound (EUS) has become an indispensable modality for the assessment of the gastrointestinal tract and adjacent structures since its origin in the 1980s. Following the development of the linear echoendoscope, EUS has evolved from a purely diagnostic modality to a sophisticated tool for intervention, with numerous luminal, pancreaticobiliary, and hepatic applications. Broadly, these applications may be subdivided into three categories: transluminal drainage or access procedures, injection therapy, and EUS-guided liver interventions. Transluminal drainage or access procedures include management of pancreatic fluid collection, EUS-guided biliary drainage, EUS-guided bile duct drainage, EUS-guided pancreatic duct drainage, and enteral anastomosis formation. Injection therapies include therapeutic EUS-guided injections for management of malignancies accessible by EUS. EUS-guided liver applications include EUS-guided liver biopsy, EUS-guided portal pressure gradient measurement, and EUS-guided vascular therapies. In this review, we discuss the origins of each of these EUS applications, evolution of techniques leading to the current status, and future directions of EUS-guided interventional therapy.

Endoscopic Ultrasound Gastro-Enteroanastomosis for Benign Gastric Outlet Obstruction due to Large Duodenal Diverticula.

Gastric outlet obstruction is a condition characterized by inadequate gastric emptying due to benign or malignant conditions inducing an inadequate oral intake. In recent years, a novel therapeutic treatment for this condition is given by the use of electrocautery lumen-apposing metal stents. In this case report, we want to present an example of a benign condition treated by endoscopic ultrasound-guided gastroenterostomy with the bi-flanged SpaxusTM stent (Taewoong Medical Co.) mounted on electrocautery catheter.

Current uses of electro-cautery lumen apposing metal stents in endoscopic ultrasound guided interventions.

The electro-cautery lumen apposing metal stent (EC-LAMS) is a newly developed device that integrates the electro-cautery cyctotome with the one-step metal stent delivery and releasing system in recent years. LAMS was first designed to complete the drainage of pancreatic fluid collection under endoscopic ultrasound guidance, and the technological innovation of EC-LAMS has made more off-labeled indications of endoscopic intervention for gastrointestinal diseases realized, such as abdominal fluid drainage, bile duct, or gallbladder drainage through stomach or duodenum, gastrointestinal anastomosis, and the establishment of fistulous channel for further endoscopic operation when necessary. The unique feature of this metal stent is that it has the design of a saddle shape and a large lumen, and can almost connect the adjacent structures to minimize the risk of perforation and leakage. Compared with traditional LAMS, EC-LAMS, an advanced integrated device, can greatly simplify the endoscopic process, shorten the procedure time and reduce the technical difficulty, thus it can help endoscopists complete more complex endoscopic interventions. In this review, we discuss the state of art with regard to EC-LAMS and its endoscopic process, current indications, outcomes, adverse events, and future application prospects.

Afferent-Loop Syndrome Treated with Endoscopic Ultrasound-Guided Drainage of the Afferent Loop with a Plastic Stent.

Afferent-loop syndrome (ALS) is known as a rare complication of partial or total gastrectomy and also occurs after pancreatoduodenectomy. The symptoms of ALS vary with the location of the mechanical obstruction, and the choice of therapeutic method should reflect the patient's condition and disease state. Herein, we report the use of endoscopic ultrasound (EUS)-guided afferent loop drainage with a plastic stent and its reintervention for malignant ALS. An 80-year-old man was admitted to our hospital with abdominal pain. Thirty-two months before, the patient underwent left hepatectomy with choledochojejunostomy and Roux-en-Y reconstruction for hilar biliary adenocarcinoma. An abdominal CT scan showed a dilated afferent loop and a low-density lesion in the peritoneum that suggested recurrence of hilar biliary adenocarcinoma and malignant ALS due to mechanical obstruction of the afferent loop caused by peritoneal dissemination. The recurrence site did not include the choledochojejunostomy anastomosis and was far distal to it. We employed a convex EUS scope and directly punctured the afferent loop from the stomach. We inserted one double pig-tail stent, and the ALS immediately improved. Five months later, ALS recurred, and we exchanged a plastic stent through the fistula. After reintervention, ALS did not recur before the patient's death due to cancer progression.

Current Status of Endoscopic Biliary Drainage in Patients with Distal Malignant Biliary Obstruction.

Distal malignant biliary obstruction is caused by various malignant diseases that require biliary drainage. In patients with operable situations, preoperative biliary drainage is required to control jaundice and cholangitis until surgery. In view of tract seeding, endoscopic biliary drainage is the first choice. Since neoadjuvant therapies are being developed, the time to surgery is increasing, especially in pancreatic cancer cases. Therefore, it requires long stent patency. Recently, preoperative biliary drainage using self-expandable metal stents has been reported as a useful modality to secure long stent patency. In patients with unresectable distal malignant biliary obstruction, self-expandable metal stent is the first choice for maintaining long stent patency. Although there are many comparison studies between a covered and an uncovered self-expandable metal stent, their use is still controversial. Recently, endoscopic ultrasound-guided biliary drainage has been performed as an alternative treatment. The clinical success and stent patency are favorable. We should take into consideration that both endoscopic retrograde cholangiopancreatography-guided biliary drainage and endoscopic ultrasound-guided biliary drainage have advantages and disadvantages and chose the drainage method depending on the patient's situation or the expertise of the endoscopist. Here, we discuss the current status of endoscopic biliary drainage in patients with distal malignant biliary obstruction.

Endoscopic ultrasound-guided fiducial marker placement for neoadjuvant chemoradiation therapy for resectable pancreatic cancer.

BACKGROUND: Preoperative neoadjuvant chemoradiation therapy (NACRT) is applied for resectable pancreatic cancer (RPC). To maximize the efficacy of NACRT, it is essential to ensure the accurate placement of fiducial markers for image-guided radiation. However, no standard method for delivering fiducial markers has been established to date, and the nature of RPC during NACRT remains unclear. AIM: To determine the feasibility, safety and benefits of endoscopic ultrasound-guided (EUS) fiducial marker placement in patients with RPC. METHODS: This was a prospective case series of 29 patients (mean age, 67.5 years; 62.1% male) with RPC referred to our facility for NACRT. Under EUS guidance, a single gold marker was placed into the tumor using either a 19- or 22-gauge fine-needle aspiration needle. The differences in daily marker positioning were measured by comparing simulation computed tomography and treatment computed tomography. RESULTS: In all 29 patients (100%) who underwent EUS fiducial marker placement, fiducials were placed successfully with only minor, self-limiting bleeding during puncture observed in 2 patients (6.9%). NACRT was subsequently administered to all patients and completed in 28/29 (96.6%) cases, with one patient experiencing repeat cholangitis. Spontaneous migration of gold markers was observed in 1 patient. Twenty-four patients (82.8%) had surgery with 91.7% (22/24) R0 resection, and two patients experienced complete remission. No inflammatory changes around the marker were observed in the surgical specimen. The daily position of gold markers showed large positional changes, particularly in the superior-inferior direction. Moreover, tumor location was affected by food and fluid intake as well as bowel gas, which changes daily. CONCLUSION: EUS fiducial marker placement following NACRT for RPC is feasible and safe. The RPC is mobile and is affected by not only aspiration, but also food and fluid intake and bowel condition.

Current Status of Needles in the Optimization of Endoscopic Ultrasound-Guided Procedures.

Endoscopic ultrasound (EUS) is among the most important tools for the evaluation of gastrointestinal tumors and affected areas around the gastrointestinal tract. It enables the acquisition of material from abnormal lesions via the gastrointestinal wall for tissue confirmation via endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). EUS-FNA has played a vital role in oncological care and has become the standard method for tissue sampling. The choice of needle type is an important factor determining tissue acquisition and has been evaluated by many researchers. New needles are introduced into the market almost every year, and opinions vary regarding proper needle selection. While there are diverse opinions but no definitive recommendations about the use of one particular device, fine-needle biopsy needles may provide detailed information on a tissue's architecture based on greater sample yields. This permits additional analyses, including genetic sequencing and phenotyping, thereby enabling the provision of more personalized treatment plans. Furthermore, other EUS-guided procedures have been developed, including interventional EUS and through-the-needle devices. Given the continued attempts to improve the diagnostic ability and therapeutic techniques, we review in detail the available types of puncture needles to provide guidance on the selection of the appropriate needle types.

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 EUS-BD 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 EUS-BD 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.

Infectious peritonitis after endoscopic ultrasound-guided biliary drainage in a patient with ascites

SUMMARY OF EVENT: Bacterial, mycotic peritonitis and Candida fungemia developed in a patient with moderate ascites who had undergone endoscopic ultrasound-guided biliary drainage (EUS-BD). Antibiotics and antifungal agent were administered and ascites drainage was performed. Although the infection improved, the patient's general condition gradually deteriorated due to aggravation of the primary cancer and he died. TEACHING POINT: This is the first report to describe infectious peritonitis after EUS-BD. Ascites carries the potential risk of severe complications. As such, in patients with ascites, endoscopic retrograde cholangiopancreatography (ERCP) is typically preferred over EUS-BD or percutaneous drainage to prevent bile leakage. However, ERCP may not be possible in some patients with tumor invasion of the duodenum or with surgically altered anatomy. Thus, in patients with ascites who require EUS-BD, we recommend inserting the drainage tube percutaneously and draining the ascites before and after the intervention in order to prevent severe infection.

Therapeutic Interventional Endoscopic Ultrasound Based on Rare Cases in Indonesia: A Single-Center Experience in Unselected Patients.

BACKGROUND: Endoscopic ultrasound (EUS) is still not widely available and has a barrier in most Southeast Asian countries due to lack of training program, high cost, and hospital investment. In this study, we would like to show the impact of therapeutic interventional EUS procedures in gastroenterology practice in Indonesia, which represents the biggest Southeast Asian country. METHODS: Patients who underwent interventional EUS procedure in Medistra Hospital were prospectively recruited within 1 year. RESULTS: Of 147 patients who underwent EUS procedures, 39 patients underwent fine needle aspiration. Most of the cases suffered from pancreatic cancer (47.5%) followed by ampullary cancer (20%), gastric subepithelial mass (10%), and other conditions. There were 4 rare cases that underwent therapeutic interventional EUS procedures. Patients with large mesenteric cyst attached to the gastric wall and large left liver lobe cyst with gastric compression who were previously suspected with gastrointestinal stromal tumor were successfully managed by cyst aspiration. One patient with a large pseudocyst due to chronic pancreatitis was successfully managed by plastic stent placement. Another patient with duodenal duplication cyst causing duodenal obstruction was managed by inserting a plastic stent through the cyst. No complications were observed during and after the therapeutic EUS procedures. CONCLUSIONS: Innovation in interventional EUS has a high impact in gastroenterology practice as well as in a developing country like Indonesia, which represents the biggest Southeast Asian country. Further developments are needed regarding the cost, investment, and especially the necessary training curriculum to make this technology available in tertiary referral centers.

Interventional EUS Using a Flexible 19-Gauge Needle: An International Multicenter Experience in 162 Patients.

BACKGROUND AND AIMS: To facilitate access for interventional EUS, flexible (nitinol) 19-G needles have been introduced to permit needle puncture even when the echoendoscope is in an angulated position, such as in the second part of the duodenum. The aims of the study were to evaluate the performance of a flexible 19-G needle during interventional EUS procedures and compare outcomes when the echoendoscope was in the straight versus angulated position. METHODS: A retrospective review was undertaken of 162 consecutive patients that underwent a variety of interventional EUS procedures with a flexible 19-G needle across five centers. Patients were subdivided into categories (straight or angulated) depending on the echoendoscope position used for obtaining access to the area of interest (Fig. 1). Fig. 1 Flexible 19-G needle design. a The needle is able to exit the sheath despite the rotated position. b The needle beveled needle tip RESULTS: In the entire cohort, needle-specific technical success was achieved in 93.2 %, procedural success in 85.2 %, and overall clinical success in 76.5 % of cases at a mean follow-up of 3.1 months. Needle-specific technical success was similar between the straight and angulated cohorts (94.0 vs. 91.2 %, p = 0.74). Procedural success (86.7 vs. 77.2 %, p = 0.05), and rate of clinical success was similar between the cohorts (83.3 vs. 86.4 %, p = 0.79), respectively. Overall adverse events were noted in 14.2 % of patients with no difference between the straight and angulated cohorts (p = 0.48). CONCLUSIONS: This study demonstrates equivalent technical success, clinical success and safety of using a flexible 19-G needle in straight and angulated endoscope positions for interventional EUS. Therefore, a flexible needle may be considered where an angulated echoendoscope position is encountered.

Development of a new reagent for endoscopic ultrasound-guided celiac plexus neurolysis and tumor ablation therapy

BACKGROUND: Both endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) and tumor ablation using ethanol are very common procedures, and the utility of these therapies has already been reported in prominent journals. However, their effectiveness appears temporary and insufficient, especially EUS-CPN. We therefore have to consider new reagents for improving the results. The present study examined the best concentration of ethanol and povidone iodine mixed with atelocollagen for more effective therapies. METHODS: The effects of the new reagents were confirmed in three live pigs. At first, we injected three kinds of reagents (including indigo carmine) in three separate areas of para-aortic tissue under EUS guidance in one pig. At more than 4 hours after injection, we checked ethanol injection sites after dissection. In next study, we performed EUS-guided injection of a total of six kinds of reagents (two kinds of ethanol, three kinds of povidone iodine, and control atelocollagen) into the livers of two living pigs. After 2 weeks, we examined tissue damage to the liver in the two pigs. RESULTS: The 75% ethanol (absolute ethanol 3.75 mL + 1% atelocollagen 1.25 mL + a very small amount of indigo carmine) was seen like blue gel, and still remained in the para-aortic tissue. Brownish areas of povidone iodine mixed with 3% atelocollagen exhibited clear, regular borders with greatly reduced infiltration into surrounding tissue compared to others. CONCLUSION: We concluded that 75% ethanol mixed with 1% atelocollagen appears optimal for EUS-CPN. Povidone iodine mixed with 3% atelocollagen may be suitable for small tumor ablation therapy.

Efficacy of endoscopic ultrasound-guided hemostatic interventions for resistant nonvariceal bleeding.

A subset of patients with nonvariceal gastrointestinal bleeding fail, or are unsuitable candidates for, endoscopic, radiologic, and surgical interventions. Endoscopic ultrasound (EUS)-guided intervention might be effective in these patients. We performed EUS-guided hemostatic interventions for 17 patients with nonvariceal gastrointestinal bleeding from June 2003 through May 2014 who failed, or were unsuitable candidates for, additional therapies. Indications for treatment included gastrointestinal stromal tumors, colorectal vascular malformations, duodenal masses or polyps, Dieulafoy lesions, duodenal ulcers, rectally invasive prostate cancer, pancreatic pseudoaneurysms, ulcerated esophageal cancer, and ulceration after Roux-en-Y gastric bypass. After the procedure, 88% of patients have had no further bleeding related to the treated lesion, over a median follow-up period of 12 months. EUS-guided hemostatic therapy therefore is feasible and useful for select patients with clinically severe, refractory, or recurrent nonvariceal gastrointestinal bleeding.

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 EUS-staging is predictive of surgical resectability. In contrast, linear array endoscope uses a side-viewing probe and has advantages in the ability to perform EUS-guides 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".

A case of pyometra treated with endoscopic ultrasound-guided drainage.

A 90-year-old woman was admitted to our hospital because of a high-grade fever and appetite loss. On computed tomography scan, a huge cystic lesion about 10 cm in diameter was observed in the pelvic cavity, attached to the vagina and the neck of uterus. Pyometra was strongly suspected; however, a probe could not be inserted into the opening of the uterus because of atrophic changes. Therefore, we decided to perform endoscopic ultrasound (EUS)-guided drainage of the pyometra using the transrectal route. Foul-smelling yellow-brown pus was aspirated. A guide-wire was inserted and a 7 Fr catheter was inserted into the pyometra through an external fistula. We thus completed the treatment of pyometra without surgical resection.

Interventional endoscopic ultrasound: Therapeutic capability and potential.

The linear echoendoscope, introduced in the 1990s, opened the era of interventional endoscopic ultrasound (IEUS). The linear echoendoscope enabled EUS guided Fine Needle Aspiration (EUS-FNA) allowing the path of the needle to be traced during the puncture process. After EUS-FNA, other interventional procedures were introduced in clinical practice. Tissue acquisition was the first EUS-guided interventional procedure and its higher diagnostic quality has undoubtedly been established. After EUS-FNA, Celiac plexus neurolysis (CPN) and block (CPB), pancreatic pseudocyst drainage, abdominal and mediastinal collections/abscesses drainage, and in selected cases, pancreatic and biliary ductal system drainage, were introduced in clinical practice. EUS-guided fine needle injection with local delivery of antitumor agents is considered a promising modality. We have reviewed published data on EUS guided interventional procedures with the object of summarizing the diagnostic capability of endoscopic ultrasound and elaborates in detail its therapeutic capability and potential.