Efficacy of a novel lumen-apposing metal stent for the treatment of symptomatic pancreatic pseudocysts (with video)

Lumen-apposing-metal stent misdeployment in endoscopic ultrasound-guided drainages: A systematic review focusing on issues and rescue management

BACKGROUND

The introduction of lumen-apposing metal stents (LAMS) for endoscopic ultrasound (EUS)-guided drainages has marked a turning point in the field of interventional ultrasound and it is gathering worldwide diffusion in different clinical settings. Nevertheless, the procedure may conceal unexpected pitfalls. LAMS misdeployment is the most frequent cause of technical failure and it can be considered a procedure-related adverse event when it hampers the conclusion of the planned procedure or results in significant clinical consequences. Stent misdeployment can be managed successfully by endoscopic rescue maneuvers to allow the completion of the procedure. To date, no standardized indication is available to guide an appropriate rescue strategy depending on the type of procedure or of misdeployment.

AIM

To evaluate the incidence of LAMS misdeployment during EUS-guided choledochoduodenostomy (EUS-CDS), gallbladder drainage (EUS-GBD) and pancreatic fluid collections drainage (EUS-PFC) and to describe the endoscopic rescue strategies adopted under the circumstance.

METHODS

We conducted a systematic review of the literature on PubMed by searching for studies published up to October 2022. The search was carried out using the exploded medical subject heading terms “lumen apposing metal stent”, “LAMS”, “endoscopic ultrasound” and “choledochoduodenostomy” or “gallbladder” or “pancreatic fluid collections”. We included in the review on-label EUS-guided procedures namely EUS-CDS, EUS-GBD and EUS-PFC. Only those publications reporting EUS-guided LAMS positioning were considered. The studies reporting a technical success rate of 100% and other procedure-related adverse events were considered to calculate the overall rate of LAMS misdeployment, while studies not reporting the causes of technical failure were excluded. Case reports were considered only for the extraction of data regarding the issues of misdeployment and rescue techniques. The following data were collected from each study: Author, year of publication, study design, study population, clinical indication, technical success, reported number of misdeployment, stent type and size, flange misdeployed and type of rescue strategy.

RESULTS

The overall technical success rate of EUS-CDS, EUS-GBD and EUS-PFC was 93.7%, 96.1%, and 98.1% respectively. Significant rates of LAMS misdeployment have been reported for EUS-CDS, EUS-GBD and EUS-PFC drainage, respectively 5.8%, 3.4%, and 2.0%. Endoscopic rescue treatment was feasible in 86.8%, 80%, and 96.8% of cases. Non endoscopic rescue strategies were required only in 10.3%, 16% and 3.2% for EUS-CDS, EUS-GBD, and EUS-PFC. The endoscopic rescue techniques described were over-the-wire deployment of a new stent through the created fistula tract in 44.1%, 8% and 64.5% and stent-in-stent in 23.5%, 60%, and 12.9%, respectively for EUS-CDS, EUS-GBD, and EUS-PFC. Further therapeutic option were endoscopic rendezvous in 11.8% of EUS-CDS and repeated procedure of EUS-guided drainage in 16.1% of EUS-PFC.

CONCLUSION

LAMS misdeployment is a relatively common adverse event in EUS-guided drainages. There is no consensus on the best rescue approach in these cases and the choice is often made by the endoscopist relying upon the clinical scenario, anatomical characteristics, and local expertise. In this review, we investigated the misdeployment of LAMS for each of the on-label indications focusing on the rescue therapies used, with the aim of providing useful data for endoscopists and to improve patient outcomes.

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.

A novel bipolar electrocautery-enhanced delivery system with a lumen-apposing metal stent for EUS-guided drainage: A porcine study

BACKGROUND

An electrocautery-enhanced delivery system with a lumen-apposing metal stent (LAMS) is available for one-step endoscopic ultrasound-guided transmural drainage (EUS-TD). Bipolar electrosurgery has several potential clinical advantages, including reduced collateral thermal damage, enhanced hemostasis, and no requirement for a return electrode plate. In this study, we compared the technical feasibility and safety of a newly developed bipolar electrocautery-enhanced delivery system with a conventional delivery system for EUS-TD using a LAMS in a porcine model.

METHOD

Ten days before the study, 12 mini pigs underwent common bile duct ligation for EUS-guided gallbladder drainage. Transenteric puncture was performed, followed by placement of a guidewire. In six pigs, a bipolar electrocautery-enhanced delivery system with LAMS (Hot SPAXUS) was inserted over the guidewire and advanced into the gallbladder, without prior dilation of the tract, by applying a bipolar cut current. In the remaining six pigs, a conventional delivery system with LAMS (Cold SPAXUS) was inserted after tract dilatation using a cystotome. The stent was removed after 4 weeks.

RESULTS

In all pigs, the stent was successfully inserted and deployed in the gallbladder without adverse events. The mean procedure time of EUS-TD was significantly lower in the Hot SPAXUS group than that of the Cold SPAXUS group (mean ± standard deviation: 188.7 ± 5.2 vs 449.5 ± 97.5 s, P = .0019). Stent migration was not observed, and all stents were removed successfully.

CONCLUSIONS

Endoscopic ultrasound-guided transmural drainage using a bipolar electrocautery-enhanced LAMS is feasible for reducing the procedure time while maintaining the high success rate and safety of conventional LAMS.

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.

Clinical outcomes of EUS-guided transluminal drainage with a novel lumen-apposing metal stent for postoperative pancreatic fluid collection after pancreatic surgery

BACKGROUND AND AIMS

EUS-guided transluminal drainage (EUS-TD) is increasingly used for the treatment of postoperative pancreatic fluid collections (POPFCs). A novel lumen-apposing metal stent (LAMS) was recently developed and used for the drainage of POPFCs. This study aimed to evaluate the efficacy and safety of a novel LAMS in patients with POPFCs.

METHODS

Forty-seven patients with symptomatic POPFCs who underwent EUS-TD with a novel LAMS (Niti-S SPAXUS; Taewoong Medical Co, Ltd, Ilsan, South Korea) between April 2019 and July 2020 were included in this study. Clinical outcomes, including technical success, clinical success, and adverse events, were retrospectively evaluated.

RESULTS

EUS-TD was technically successful in 41 of 47 patients (87.2%). Clinical success was achieved in 37 of 41 patients (90.2%). The mean procedure time was 13.7 ± 3.5 minutes. The mean POPFC size was 59 ± 18.9 mm. The mean time interval from surgery to EUS-TD was 24.2 ± 37.6 days. Five patients experienced 6 procedural adverse events (12.8%): 4 (8.5%) POPFC infections and 2 (4.3%) distal stent migrations. The 4 patients with POPFC infection underwent additional endoscopic interventions. Of the 2 patients with stent migration, 1 underwent laparoscopic exploration and surgical extraction of the stent and 1 (2.1%) experienced POPFC recurrence, which was managed with percutaneous drainage.

CONCLUSIONS

EUS-TD for symptomatic POPFCs with a novel LAMS is technically feasible and effective, with an acceptable adverse event rate. Further larger-scale prospective studies are required to confirm the findings of this study.

Experimental study of a physician-controlled electrocautery-enhanced delivery system incorporating a newly developed lumen-apposing metal stent for interventional endoscopic ultrasound (with videos)

BACKGROUND/PURPOSE

Although the lumen-apposing metal stent (LAMS) is useful for interventional endoscopic ultrasound (EUS) procedures, there has been some concern about the potential for stent-induced adverse events because of the high lumen-apposing force. A newly designed LAMS with less lumen-apposing force has been developed for use with a physician-controlled electrocautery-enhanced delivery system. The aim of this animal study was to evaluate the feasibility of performing interventional EUS using this newly designed LAMS system.

METHODS

EUS-guided cystogastrostomy was performed using the novel LAMS 3 times in a wet simulation model. EUS-guided gastroenterostomy and EUS-guided gallbladder drainage were then performed using the system in 4 pigs.

RESULTS

The LAMS was successfully placed in all 3 EUS-guided cystogastrostomy procedures using the wet simulation model and in all 4 EUS-guided gastroenterostomy and gallbladder drainage procedures in the animal model. In the 3 weeks following the procedure, eating behavior was normal in all animals and there were no adverse events. The stents remained patent during this time and were removed without difficulty. The fistula was mature in all cases and a standard upper gastrointestinal endoscope was easily advanced via the fistula to observe the afferent and efferent loops or the lumen of the gallbladder. Necropsy confirmed complete adhesion between the stomach and the wall of the jejunum or gallbladder.

CONCLUSIONS

Our study findings demonstrate the feasibility of this new LAMS system and its potential clinical value for interventional EUS.

Use of a novel lumen apposing metallic stent for drainage of the bile duct and gallbladder: Long term outcomes of a prospective international trial

BACKGROUND

Long-term placement of lumen apposing metal stents (LAMS) with high lumen apposing force may result in adverse events. The aim of the current study was to assess the long-term efficacy and safety of a self-approximating LAMS with lower lumen apposing force for endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) and -gallbladder drainage (EUS-GBD).

METHODS

Five Asian institutions participated in this study. Consecutive patients suffering from obstructive jaundice with failed ERCP or acute cholecystitis that were at high risk for cholecystectomy were recruited. We evaluated the technical and clinical success rates, adverse events rates, types of interventions through the stent and the patency profile.

RESULTS

From June 2017 to Oct 2018, a total of 53 patients received EUS-CDS (26) and EUS-GBD (27). The technical and clinical success rates were similar between the two groups (88.5% vs 88.9%, P = 1 and 88.5% vs 88.9%, P = 1 respectively). The differences in 30-day mortality rates [2 (7.7%) vs 2 (7.7%), P = 1] and adverse events [3 (11.5%) vs 3 (11.5%), P = 1] did not reach significance. Regarding long-term outcomes, two patients in each group suffered from adverse events (P = 1). One patient in the EUS-GBD group who was on direct oral anticoagulant suffered from stent induced bleeding.

CONCLUSION

The self-approximating LAMS with lower lumen apposing force was effective and safe with a low risk of buried stent syndrome and bleeding in the longer term. The ClinicalTrials.gov Identifier was NCT03002051.

A novel electrocautery-enhanced delivery system for one-step endoscopic ultrasound-guided drainage of the gallbladder and bile duct using a lumen-apposing metal stent: a feasibility study

BACKGROUND

The use of a lumen-apposing metal stent (LAMS) capable of one-step endoscopic ultrasound-guided transmural drainage (EUS-TD) can increase the effectiveness of the procedure. We evaluated the newly developed electrocautery-enhanced (EC) delivery system with a LAMS for one-step EUS-guided gallbladder drainage (EUS-GBD) or choledochoduodenostomy (EUS-CDS).

METHODS

In the animal experiment, an EC-LAMS was advanced into the gallbladder without prior tract dilation in four pigs. A conventional LAMS was inserted in another four pigs as a control group. After the animal experiment, 17 patients underwent EUS-TD using the EC-LAMS (EUS-GBD in 10 patients, EUS-CDS in 7). The primary outcome was the technical success rate.

RESULTS

In the animal study, the mean procedure time was significantly shorter in the EC-LAMS group than in the conventional LAMS group. In the human study, the overall technical success rate was 94.1 %, with one EUS-GBD failure. The clinical success rate was 100 %. The overall adverse event rate was 17.6 %.

CONCLUSIONS

One-step EUS-GBD or EUS-CDS using the novel EC-LAMS is a feasible approach that achieves a high success rate and maintains safety.

Technical tips and recent development of endoscopic ultrasound-guided choledochoduodenostomy

Various efforts to improve technical success rates and decrease adverse event rates have also been described in endoscopic ultrasound (EUS)-guided choledochoduodenostomy (CDS). In particular, lumen-apposing metal stents (LAMS) may open novel opportunities in EUS-biliary drainage (BD). To date, various studies have been reported with EUS-CDS using LAMS, so we should clarify the benefits and limitations of recent EUS-CDS based on developments in both techniques and devices. In this review, we provide technical tips and describe recent developments in EUS-CDS, along with a review of the recent literature (between 2015 and 2020). The overall technical success rate is 95.0% (939/988), and the overall clinical success rate is 97.0% (820/845). The most frequent adverse event is cholangitis or cholecystitis (24.5%, 27/110). According to previous review, pneumoperitoneum (28%, 9/34) or peritonitis associated with bile leak (23.5%, 8/34) was most commonly observed. This difference might be based on improvements in dilation devices or the use of covered metal stents. Several randomized controlled trials comparing EUS-CDS and endoscopic retrograde cholangiopancreatography (ERCP) for malignant biliary obstruction have recently been reported. To summarize, overall technical success rates for ERCP and EUS-CDS were 92.7% (101/109) and 91.1% (72/79), respectively (p = 0.788). Overall clinical success rates for ERCP and EUS-CDS were 94.1% (96/102) and 93.6% (72/78), respectively (p = 0.765). Further high-quality evidence is needed to establish EUS-CDS as a primary drainage technique.

Effectiveness of early endoscopic ultrasound-guided drainage for postoperative fluid collection

BACKGROUND

Postoperative abdominal fluid collections (PAFCs) are a potentially fatal complication of pancreatobiliary surgery. Endoscopic ultrasound (EUS)-guided drainage has recently been shown to be effective in treating PAFCs of more than 4 weeks old. Little is currently known, however, regarding the EUS-guided drainage of PAFCs of less than 4 weeks. This study assessed the efficacy and safety of the early drainage (< 4 weeks) of PAFCs via EUS guidance.

METHODS

The data of patients who had undergone EUS-guided PAFC drainage between July 2008 and January 2018 were retrospectively analyzed. Data of EUS-guided PAFC drainage were obtained from prospectively collected EUS database of our institute and reviewed of patients' clinical parameters based on electrical medical record.

RESULTS

A total of 48 patients who had undergone EUS-guided PAFC drainage within 4 weeks of pancreatobiliary surgery were enrolled. The indications of procedure included abdominal pain (n = 27), fever (n = 18), leukocytosis (n = 2), and increased size of PAFC during external tube drainage (n = 1). Technical success was achieved in all cases, and the clinical success rate was 95.8% (46/48). Four patients underwent secondary procedures. The median period from surgery to EUS-guide drainage was 14 days (Interquartile range [IQR] 10-16), and median time to resolution was 23.5 days (IQR 8.5-33.8). Adverse events occurred in two cases that were developed intracystic bleeding and were successfully resolved by arterial coil embolization.

CONCLUSIONS

Early EUS-guided drainage is a technically feasible, effective, and safe method in patients who have developing PAFCs within 4 weeks of pancreatobiliary surgery.

Endoscopic ultrasound-guided anastomosis: Is it ready for prime time?

Significant advancements in endoscopic ultrasound (EUS)-guided drainage procedures and EUS-guided anastomosis have recently been described. The described procedures include EUS-guided drainage of pancreatic fluid collections, biliary drainage, pancreatic duct drainage, gallbladder drainage, and gastroenterostomy. These procedures have been made possible with novel devices that can reduce the difficulties of the procedures and potentially reducing the risk of adverse events. The procedures are also becoming standardized, which is essential for dissemination of the techniques. Furthermore, results from randomized studies are becoming available showing definite benefits associated with these procedures. In this paper, we will provide a review on EUS-guided anastomotic procedures.

Advancements in the endoscopic treatment of pancreatic fluid collections

Endoscopic drainage of pancreatic fluid collections (PFCs) with fewer complications and less trauma has gradually replaced surgery or percutaneous drainage to become the first-line treatment for PFCs. In recent years, the differential efficacy of various stent techniques to drain different types of PFCs has been controversial. This review summarizes the clinical applications of endoscopic ultrasound-guided stent placement for PFCs drainage.

Are Lumen-Apposing Metal Stents More Effective Than Plastic Stents for the Management of Pancreatic Fluid Collections: An Updated Systematic Review and Meta-analysis

Background and Aims

Recently, a new type of metal stent, named lumen-apposing metal stents (LAMS), has been designed to manage pancreatic fluid collections (PFC), and a few studies have reported its efficacy and safety. Therefore, we conducted this meta-analysis to investigate the role of LAMS for PFC.

Methods

We searched the studies from PubMed, MEDLINE, Embase, and Cochrane databases from inception to May 2019. We extracted the data and analyzed the technical success, clinical success, and adverse events of LAMS to evaluate its efficacy and safety.

Results

Twenty studies with 1534 patients were included. The pooled technical success, clinical success, and adverse event rates of LAMS for PFC were 96.2% (95% confidence interval (CI): 94.6%-97.4%), 86.8% (95% CI: 83.1%-89.8%), and 20.7% (95% CI: 16.1%-26.1%), respectively. Eight studies including 875 patients compared the clinical outcomes of LAMS with plastic stents. The pooled risk ratio (RR) of technical success and clinical success for LAMS and plastic stent was 1.01 (95% CI: 0.98-1.04, P = 0.62) and 1.06 (95% CI: 1.01-1.12, P = 0.03), respectively. As for the overall adverse events, the pooled RR was 1.51 (95% CI: 0.67-3.44, P = 0.32).

Conclusions

Our current study revealed that LAMS has advantages over plastic stents for PFC, with higher clinical success rate and lower complication rate of infection and occlusion.