Technical review of endoscopic ultrasound-guided drainage/anastomosis and trans-endosonographically created route procedures for the treatment of pancreatic diseases.

Endoscopic ultrasound (EUS)-guided pancreatic duct drainage includes two procedures: EUS-guided drainage/anastomosis (EUS-D/A) and trans-papillary drainage with EUS-assisted pancreatic rendezvous. EUS-guided pancreatogastrostomy is the most common EUS-D/A procedure and is recommended as a salvage procedure in cases in which endoscopic retrograde cholangiopancreatography fails or is difficult. However, initial EUS-D/A is performed in patients with surgically altered anatomy at our institution. It is one of the most difficult interventional EUS procedures and has a high incidence of adverse events. The technical difficulties differ according to etiology, and the incidence of adverse events varies between initial EUS-D/A and subsequent trans-endosonographically/EUS-guided created route procedures. Hence, it is important to meticulously prepare a procedure based on the patient's condition and the available devices. The technical difficulties in EUS-D/A include: (1) determination of the puncture point, (2) selection of a puncture needle and guidewire, (3) guidewire manipulation, and (4) dilation of the puncture route and stenting. Proper technical procedures are important to increase the success rate and reduce the incidence and severity of adverse events. The complexity of EUS-D/A is also contingent on the severity of pancreatic fibrosis and stricture. In post-pancreatectomy cases, determination of the puncture site is important for success because of the remnant pancreas. Trans-endosonographically/EUS-guided created route procedures following initial EUS-D/A are also important for achieving the treatment goal. This article focuses on effective strategies for initial EUS-D/A, based on the etiology and condition of the pancreas. We mainly discuss EUS-D/A, including its indications, techniques, and success-enhancing strategies.

EUS-guided hydrogel injection to separate pancreatic head carcinoma from duodenum for enhanced radiotherapy: Multi-site feasibility study.

Background and study aims The proximity of a pancreas head tumor to the duodenum often limits delivery of an ablative dose of radiation therapy. This study evaluated the feasibility and safety of using an injectable polyethylene glycol (PEG) hydrogel between the head of the pancreas and duodenum. Patients and methods In a multi-site feasibility cohort study of patients with localized pancreatic cancer, PEG hydrogel was injected under endoscopic ultrasound guidance to temporarily position the duodenum away from the pancreas. Procedure characteristics were recorded, including hydrogel volume and space created. Patients were monitored for adverse events (AEs) and radiotherapy toxicity. Results In all six intent-to-treat patients (four with borderline resectable, two with locally advanced disease), the ability to place and visualize PEG hydrogel and create space between the duodenum and the head of the pancreas was successful. There were no procedure-related AEs resulting in radiotherapy delay. There were no device-related AEs and no reports of pancreatitis. Conclusions PEG hydrogel was successfully placed, created space between the duodenum and the head of the pancreas, and was not associated with major toxicity. Enhancing radiotherapy for pancreatic cancer by using PEG hydrogel to create peri-duodenal space could have beneficial implications for treatment and warrants more exploration.

Structural factors influencing the clinical performance of 0.025-inch guidewires for pancreatobiliary endoscopy: An experimental study.

Background and study aims To develop a pancreatobiliary endoscopic guidewire with good clinical performance, an understanding of its structure is necessary. This study aimed to investigate the structural factors influencing the clinical performance of pancreatobiliary endoscopic guidewires. Methods Eight types of 0.025-inch guidewires were evaluated. The following structural properties were measured: tip length, tip deflection height, tip weight (TW), ratio of tip core weight to TW, shaft coating type (flat or uneven), outer diameter, and core wire diameter (CWD). Four performance tests were conducted to evaluate shaft stiffness as bending force (BF), shaft lubricity as friction force (FF), torque response as torque response rate (TRR), and seeking ability as total insertion success (TIS) in a technical test using a 3D bile duct model. The correlation coefficients of each variable were analyzed. Results The BF and CWDs were strongly correlated, as well as the FF and CWDs and BF. Among the guidewires with similar CWDs, the guidewires with uneven coating had significantly lower FF than those with flat coating. The TRR was strongly correlated with the CWDs; furthermore, guidewires with lower FF had better TRR. TIS was strongly correlated with the TRR, TWs, and ratio of the tip core weight to TW. Conclusions CWD affects shaft stiffness; CWD and coating type affect shaft lubricity and torque response. Because TRR and TW are correlated with seeking ability, an appropriate combination of core wire thickness, TW, and coating design is required to develop a guidewire with good seeking ability.

Complications and management of interventional endoscopic ultrasound: A critical review.

In the last decades, Endoscopic ultrasound (EUS) has rapidly grown and evolved from being mainly a diagnostic procedure, to being an interventional and therapeutic tool in several pathological clinical scenarios. With the progressive growth in technical expertise and dedicated devices, interventional endoscopic ultrasound procedures (IEUSP) have shown high rates of technical and clinical success, together with a relatively safe profile. However, the description and the standardization of different and specific types of adverse events (AEs) are still scarce in literature, and, consequently, even less the management of AEs. The aim of this study is to critical review and to describe AEs related to each of the main IEUSP, and to provide an overview on the possible management strategies of endoscopic complications. Future studies and guidelines are surely required to reach a better standardization of different AEs and their best management.

Dedicated Echoendoscope for Interventional Endoscopic Ultrasound: Comparison with a Conventional Echoendoscope.

Background/Objective: Interventional endoscopic ultrasound (I-EUS) is technically difficult and has risks of severe adverse events due to the scarcity of dedicated endoscopes and tools. A new EUS scope was developed for I-EUS and was modified to increase the puncture range, reduce the blind area, and overcome guidewire difficulties. We evaluated the usefulness and safety of a new EUS scope compared to a conventional EUS scope. Methods: All I-EUS procedures were performed at Juntendo University Hospital from April 2020 to April 2022. The primary outcomes included the procedure time and fluoroscopy time. The secondary outcomes included the technical success rate and the rates of procedure-related adverse events. Clinical data were retrospectively reviewed and statistically analyzed between the new and conventional EUS scopes. Results: In total, 143 procedures in 120 patients were analyzed. The procedure time was significantly shorter with the new EUS scope, but the fluoroscopy time was not different. Among the patients only undergoing EUS-guided biliary drainage (EUS-BD), 79 procedures in 74 patients were analyzed. Both the procedure time and fluoroscopy time were significantly shorter with the new EUS scope. Multivariate analysis revealed that a new EUS scope and use of covered metal stents could reduce the fluoroscopy time. The technical success rate and the adverse event rate were not significantly different between the total I-EUS and the EUS-BD only groups. However, the conventional scope showed stent deviation during stent placement, which did not happen with the new scope. Conclusions: The new EUS scope reduced procedure time for total I-EUS and fluoroscopy time for EUS-BD compared to a conventional EUS scope because of the improvement suitable for I-EUS.

Endoscopic Drainage of Pancreatic Fluid Collections.

Pancreatic fluid collections (PFCs) are commonly encountered complications of acute and chronic pancreatitis. With the advancement of endoscopic ultrasound (EUS) techniques and devices, EUS-directed transmural drainage of symptomatic or infected PFCs has become the standard of care. Traditionally, plastic stents have been used for drainage, although lumen-apposing metal stents (LAMSs) are now favored by most endoscopists due to ease of use and reduced procedure time. While safety has been repeatedly demonstrated, follow-up care for these patients is critical as delayed adverse events of indwelling drains are known to occur.

Endoscopic Gallbladder Drainage: A Comprehensive Review on Indications, Techniques, and Future Perspectives.

In recent years, therapeutic endoscopy has become a fundamental tool in the management of gallbladder diseases in light of its minimal invasiveness, high clinical efficacy, and good safety profile. Both endoscopic transpapillary gallbladder drainage (TGBD) and endoscopic ultrasound (EUS)-guided gallbladder drainage (EUS-GBD) provide effective internal drainage in patients with acute cholecystitis unfit for cholecystectomy, avoiding the drawbacks of external percutaneous gallbladder drainage (PGBD). The availability of dedicated lumen-apposing metal stents (LAMS) for EUS-guided transluminal interventions contributed to the expansion of endoscopic therapies for acute cholecystitis, making endoscopic gallbladder drainage easier, faster, and hence more widely available. Moreover, EUS-GBD with LAMS opened the possibility of several cholecystoscopy-guided interventions, such as gallstone lithotripsy and clearance. Finally, EUS-GBD has also been proposed as a rescue drainage modality in malignant biliary obstruction after failure of standard techniques, with encouraging results. In this review, we will describe the TBGD and EUS-GBD techniques, and we will discuss the available data on clinical efficacy in different settings in comparison with PGBD. Finally, we will comment on the future perspectives of EUS-GBD, discussing the areas of uncertainty in which new data are more strongly awaited.

Safety of skipping the tract dilation step for EUS-guided biliary drainage in patients with unresectable malignant biliary obstruction (with video).

BACKGROUND: Thin delivery system stents can be inserted directly without the need for a tract dilation step and are expected to reduce bile leakage during endoscopic ultrasound-guided biliary drainage (EUS-BD). The present study retrospectively compared the safety and efficacy of EUS-BD using a thin metal stent (< 7.5 Fr) with those of EUS-BD using a conventional stent (≥ 7.5 Fr). METHODS: The present study enrolled 112 patients who underwent EUS-BD using metal stents for unresectable malignant biliary obstruction between April 2016 and July 2022. The primary endpoint was the rate of adverse events (AEs). The secondary endpoints were clinical success rate, procedure time, procedure success rate in the absence of the tract dilation step, recurrent biliary obstruction rate, time to biliary obstruction, and overall survival. Risk factors associated with early AEs were also evaluated. RESULTS: The rate of early AEs was significantly lower (12% vs. 35%, P = 0.013) and the procedure success without the tract dilation step was significantly higher (82% vs. 33%, P < 0.001) in the thin than in the conventional delivery system stent group. None of the other secondary endpoints differed significantly between the two groups. Multivariate analysis showed that employing the tract dilation step during EUS-BD was a significant independent risk factor for early AEs (skipping vs. employing; HR, 9.66; 95% CI, 1.13-83.0, P = 0.028). CONCLUSION: Employing the tract dilation step during EUS-BD was a significant risk factor for early AEs. Metal stents with a delivery diameter < 7.5 Fr can be inserted directly without the tract dilation step, resulting in lower early AE rates.

The New potential for Using Franseen Needles in Interventional EUS.

Objective Adverse events such as bile leakage and bleeding are among the issues that need to be resolved in EUS-guided choledochoduodenostomy (EUS-CDS). To overcome this problem, we developed a new EUS-CDS technique using a 19-G Franseen needle without tract dilation. This study aimed to evaluate the safety and efficacy of the new EUS-CDS technique. Methods This single-center retrospective study included 20 consecutive patients who underwent EUS-CDS for primary drainage using a 19-G Franseen needle between March 2020 and May 2023. The primary endpoint was the technical success rate of EUS-CDS without tract dilation. Results The technical success rate of EUS-CDS was 20/20 (100%). None of the patients required any additional tract dilation, such as by using a balloon or electric cautery. The median procedure time was 7.8 (range, 3.2-19.4) min. No early adverse events were observed. Conclusion The 19-G Franseen needle appeared to have a sufficient dilatory effect during puncturing. This EUS-CDS technique appears to be safe and effective and has the advantages of no adverse events and it is also a simplified procedure, which suggests its potential for widespread use in primary drainage.

An Unusual Abscess Associated with Gallbladder Perforation Successfully Treated with Percutaneous Transhepatic Gallbladder Drainage and Endoscopic Ultrasound-guided Abscess Drainage.

Abscesses associated with gallbladder perforation are often confined to the peri-gallbladder region. We herein report a rare case of gallbladder perforation in which the abscess cavity extended into the left upper quadrant. A 79-year-old woman developed gallbladder perforation secondary to acalculous cholecystitis. Computed tomography revealed fluid collection extending from the peri-gallbladder to the dorsal left hepatic lobe in contact with the stomach. We successfully treated percutaneous transhepatic gallbladder drainage and simultaneous endoscopic ultrasound-guided transgastric internal and external abscess drainage. This minimally invasive approach is considered safe and feasible for managing such a rare case.

Endoscopic ultrasound-guided gallbladder drainage as a first approach for jaundice palliation in unresectable malignant distal biliary obstruction: Prospective study.

OBJECTIVES: Endoscopic retrograde cholangiopancreatography (ERCP) represents the gold standard for jaundice palliation in patients with distal malignant biliary obstruction (DMBO). Biliary drainage using electrocautery lumen apposing metal stent (EC-LAMS) is currently a well-established procedure when ERCP fails. In a palliative setting the endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) could represent an easy and valid option. We performed a prospective study with a new EC-LAMS with the primary aim to assess the clinical success rate of EUS-GBD as a first-line approach to the palliation of DMBO. METHODS: In all, 37 consecutive patients undergoing EUS-GBD with a new EC-LAMS were prospectively enrolled. Clinical success was defined as bilirubin level decrease >15% within 24 h and >50% within 14 days after EC-LAMS placement. RESULTS: The mean age was 73.5 ± 10.8 years; there were 17 male patients (45.9%). EC-LAMS placement was technically feasible in all patients (100%) and the clinical success rate was 100%. Four patients (10.8%) experienced adverse events, one bleeding, one food impaction, and two cystic duct obstructions because of disease progression. No stent-related deaths were observed. The mean hospitalization was 7.7 ± 3.4 days. Median overall survival was 4 months (95% confidence interval 1-8). CONCLUSION: Endoscopic ultrasound-guided gallbladder drainage with the new EC-LAMS is a valid option in palliative endoscopic biliary drainage as a first-step approach in low survival patients with malignant jaundice unfit for surgery. A smaller diameter EC-LAMS should be preferred, particularly if the drainage is performed through the stomach, to avoid potential food impaction, which could result in stent dysfunction.

3-Fr microcatheter-assisted endoscopic ultrasound-guided rendezvous technique with a 22-gauge needle and a 0.018-inch guidewire for difficult biliary cannulation.

Endoscopic ultrasound-guided rendezvous with a 22-gauge needle and a 0.018-inch guidewire, assisted by a 3-Fr microcatheter, effectively addresses challenges in biliary cannulation, improving guidewire manipulation and reducing risks of injury and leakage. Natsume and colleagues describe the successful extraction of common bile duct stones to demonstrate the efficacy of this technique.

Loop technique for guidewire manipulation during endoscopic ultrasound-guided hepaticogastrostomy.

Background and Aim: Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is widely used in the management of biliary obstructions; however, literature on guidewire manipulation is lacking. This study aimed to assess the utility and optimal conditions of the loop technique for guidewire manipulation during EUS-HGS. Methods: Consecutive patients who underwent EUS-HGS between April 2015 and January 2022 were included in this study. Patient characteristics and procedural details were retrospectively analyzed. Guidewire manipulations were classified as conventional technique or loop technique, based on the shape of the guidewire tip. Results: A total of 52 patients (Median age: 73 years, 38 male and 14 female) underwent EUS-HGS. The median guidewire insertion time was 49 s and the median overall procedure time was 20.5 min. The initial guidewire direction was toward the peripheral side in 23 patients (44%). Technical success rate of the EUS-HGS was 100%. Twenty patients (38%) underwent the procedure using the loop technique and 32 (62%) with the conventional technique. In the logistic regression analysis, an angle between the bile duct and needle of >70° was independently associated with use of the loop technique (OR 9.84; 95% CI: 2.24-43.13; P <0.01). Conclusion: This study revealed the utility of the loop technique in EUS-HGS. This technique is recommended if the bile duct is punctured at an angle >70°.

Endoscopic Ultrasound-Guided Local Ablative Therapies for the Treatment of Pancreatic Neuroendocrine Tumors and Cystic Lesions: A Review of the Current Literature.

Since its emergence as a diagnostic modality in the 1980s, endoscopic ultrasound (EUS) has provided the clinician profound access to gastrointestinal organs to aid in the direct visualization, sampling, and subsequent identification of pancreatic pathology. In recent years, advancements in EUS as an interventional technique have promoted the use of local ablative therapies as a minimally invasive alternative to the surgical management of pancreatic neuroendocrine tumors (pNETs) and pancreatic cystic neoplasms (PCNs), especially for those deemed to be poor operative candidates. EUS-guided local therapies have demonstrated promising efficacy in addressing a spectrum of pancreatic neoplasms, while also balancing local adverse effects on healthy parenchyma. This article serves as a review of the current literature detailing the mechanisms, outcomes, complications, and limitations of EUS-guided local ablative therapies such as chemical ablation and radiofrequency ablation (RFA) for the treatment of pNETs and PCNs, as well as a discussion of future applications of EUS-guided techniques to address a broader scope of pancreatic pathology.

A pilot study of Spring Stopper Stents: Novel partially covered self-expandable metallic stents with anti-migration properties for EUS-guided hepaticogastrostomy.

Background and Objectives: EUS-guided hepaticogastrostomy (EUS-HGS) is an effective salvage procedure when conventional endoscopic transpapillary biliary drainage is difficult or fails. However, the risk of stent migration into the abdominal cavity has not been resolved completely. In this study, we evaluated a newly developed partially covered self-expandable metallic stent (PC-SEMS) that has a spring-like anchoring function on the gastric side. Methods: This retrospective pilot study took place at four referral centers in Japan between October 2019 and November 2020. We enrolled 37 cases consecutively who underwent EUS-HGS for unresectable malignant biliary obstruction. Results: The rates of technical and clinical success were 97.3% and 89.2%, respectively. Technical failures included one case in which the stent was dislocated during the removal of the delivery system, requiring additional EUS-HGS on another branch. Early adverse events (AEs) were observed in four patients (10.8%): two with mild peritonitis (5.4%) and one each (2.7%) with fever and bleeding. No late AEs were observed during the mean follow-up period of 5.1 months. All recurrent biliary obstructions (RBOs) were stent occlusions (29.7%). The median cumulative time to RBO was 7.1 months (95% confidence interval, 4.3 to not available). Although stent migration in which the stopper was in contact with the gastric wall on follow-up computed tomography was observed in six patients (16.2%), no migration was observed. Conclusions: The newly developed PC-SEMS is feasible and safe for the EUS-HGS procedure. The spring-like anchoring function on the gastric side is an effective anchor preventing migration.

EUS-guided gastroenterostomy using a novel electrocautery lumen apposing metal stent for treatment of gastric outlet obstruction (with video).

BACKGROUND AND AIM: Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) for the treatment of gastric outlet obstruction (GOO) has been actually performed only with one type of electrocautery lumen-apposing metal stents (EC-LAMS). We aimed to evaluate the safety, technical and clinical effectiveness of EUS-GE using a newly available EC-LAMS in patients with malignant and benign GOO. MATERIALS AND METHODS: Consecutive patients who underwent EUS-GE for GOO using the new EC-LAMS at five endoscopic referral centers were retrospectively evaluated. Clinical efficacy was determined utilizing the Gastric Outlet Obstruction Scoring System (GOOSS). RESULTS: Twenty-five patients (64% male, mean age 68.7 ± 9.3 years) met the inclusion criteria; 21 (84%) had malignant etiology. Technically, EUS-GE was successful in all patients, with a mean procedural time of 35 ± 5 min. Clinical success was 68% at 7 days and 100% at 30 days. The mean time to resume oral diet was 11.4 ± 5.8 h, with an improvement of at least one point of GOOSS score observed in all patients. The median hospital stay was 4 days. No procedure-related adverse events occurred. After a mean follow-up of 7.6 months (95% CI 4.6-9.2), no stent dysfunctions were observed. CONCLUSION: This study suggests EUS-GE can be performed safely and successfully using the new EC-LAMS. Future large multicenter prospective studies are needed to confirm our preliminary data.

Reduction of Lams-Related Adverse Events with Accumulating Experience in a Large-Volume Tertiary Referral Center.

BACKGROUND AND AIMS: Lumen-apposing metal stents (LAMSs) are increasingly used both for on- and off-label indications. We continuously adapt our step-by-step protocol to optimize the safe deployment of LAMSs for the different indications. The aim of this study was to evaluate the impact of this approach over time. METHODS: We conducted a single-center study on consecutive patients who underwent LAMS placement for on- and off-label indications between June 2020 and June 2022. Endpoints included technical success, clinical success and adverse event rates. We compared the results with our previously published early experience with LAMSs (N = 61), between March 2018 and May 2020. RESULTS: This cohort consisted of 168 LAMSs in 153 patients. Almost half of them (47.6%) were placed for off-label indications (gastro-enterostomy, temporary access to the excluded stomach in patients with previous gastric bypass, drainage of postsurgical collections, stenting of short refractory gastrointestinal strictures). While the technical and clinical success rates were similar to those in our previously published cohort (97% and 93.5% versus 93.4% and 88.5%, respectively), the adverse event rate dropped from 21.3% to 8.9%. CONCLUSIONS: Our results demonstrate the impact of a learning curve in LAMS placement, with a clinically relevant drop in LAMS-related adverse events over time.

Measurement of the anchoring force of covered self-expandable and lumen-apposing metal stents for interventional endoscopic ultrasonography.

OBJECTIVES: Interventional endoscopic ultrasonography is performed for various situations that require drainage, after which stent migration is the most severe adverse event. Several lumen-apposing metal stents (LAMS) and covered self-expandable metal stents (CSEMS) provide antimigration systems; however, their anchoring ability has not been studied well. Therefore, we measured and compared the anchoring force (ACF) of commercially available LAMS and CSEMS. METHODS: Anchoring force was measured for five types of LAMS (NAGI, SPAXUS, Plumber, and AXIOS 8 and 10 mm) and seven types of CSEMS (BCL, SHCL, BCG, BPD [four types of HANAROSTENT], HILZO, Niti-S [Spring Stopper], and Wallflex). We created a phantom model for inducing stent migration. It has a rotatable part as a curved fixture, and we measured ACF at angles between 0° and 40°. RESULTS: The mean ACF at 0° and 20° were NAGI 1.50, 1.84 N, SPAXUS 1.73, 1.72 N, Plumber 2.64, 2.03 N, and AXIOS 3.96, 3.61 N, respectively; and BCL 0.48, 0.53 N, Wallflex 0.53, 0.48 N, SHCL 0.64, 0.73 N, HILZO 1.09, 1.09 N, BCG 1.22, 1.20 N, BPD 1.78, 1.67 N, and Spring Stopper 2.29, 2.51 N. CONCLUSION: We measured ACF in LAMS and CSEMS with a new phantom model. The highest value among the LAMS was for the AXIOS and among the CSEMS was for the Spring Stopper. Some of the ACF values varied with the direction of pull. These findings may have a significant impact on stent selection for interventional endoscopic ultrasonography, and this model can be used to evaluate newly developed stents.

Development of devices for interventional endoscopic ultrasound for the management of pancreatobiliary diseases.

A variety of devices have been developed for interventional endoscopic ultrasound (EUS). EUS-guided drainage of the bile duct and pancreatic duct, as well as fluid collection adjacent to the gastrointestinal tract, is performed by a procedure involving puncture, guidewire manipulation, tract dilation, and stent placement. Devices specialized for interventional EUS are being developed for each step of the procedure. Mechanical dilators such as bougie, balloon, and electrocautery dilators are used for tract dilation. Various types of plastic stents, self-expandable metal stents, and lumen-apposing metal stents specifically designed for interventional EUS are now available, including one-step devices developed to improve the efficacy and safety of interventional EUS. In addition, radiofrequency ablation and the placement of fiducial markers and radioactive seeds under EUS guidance are now becoming established for pancreatic neoplasms. Such development of specialized devices has expanded the indications for interventional EUS, increased the success rate, and lowered the adverse event rate.