Design considerations of the novel lumen-apposing metal stents (Niti-S SPAXUS)

Lumen-apposing metal stents: A primer on indications and technical tips

Lumen-apposing metal stents have ushered a new frontier for interventional endoscopic ultrasound. Initial use for the drainage of pancreatic fluid collections has rapidly expanded to the bile duct, gallbladder and small bowel. Intra-luminal applications for short strictures have also emerged. Electrocautery enhancement has made the stent delivery speedy. While the advent of lumen-apposing metal stents (LAMS) has brought a paradigm shift in the practice of interventional endoscopic ultrasound, their use is associated with certain technicalities that any advanced endosonologist should know. Understanding indications for LAMS is critical and their use in appropriate settings. Troubleshooting in tricky situations is always a challenge and the background considerations for their use include knowing the target organ, cautery and puncture technique, managing partially opened LAMS and also managing maldeployment. In this review, we discuss the intricacies and technical tips for the use of lumen-apposing metal stents.

Role of endoscopic ultrasound-guided biliary drainage for palliation of malignant biliary obstruction

Endoscopic ultrasound-guided biliary drainage (EUS-BD) directs bile flow into the digestive tract and has been mostly used in patients with malignant biliary obstruction (MBO) where endoscopic retrograde cholangiopancreatography-guided biliary drainage was unsuccessful or was not feasible. Lumen apposing metal stents (LAMS) are deployed during EUS-BD, with the newer electrocautery-enhanced LAMS reducing procedure time and complication rates due to the inbuilt cautery at the catheter tip. EUS-BD with electrocautery-enhanced LAMS has high technical and clinical success rates for palliation of MBO, with bleeding, cholangitis, and stent occlusion being the most common adverse events. Recent studies have even suggested comparable efficacy between EUS-BD and endoscopic retrograde cholangiopancreatography as the primary approach for distal MBO. In this editorial, we commented on the article by Peng et al published in the recent issue of the World Journal of Gastrointestinal Surgery in 2024.

Indirect comparison of various lumen-apposing metal stents for EUS-guided biliary and gallbladder drainage: a systematic review and meta-analysis

BACKGROUND AND AIMS

Studies assessing EUS-guided biliary drainage (EUS-BD) or gallbladder drainage (EUS-GB) using lumen-apposing metal stents (LAMSs) have shown variable results based on the type of LAMS. We performed a meta-analysis of the available data.

METHODS

Multiple online databases were searched for studies using LAMSs (Axios [Boston Scientific, Marlborough, Mass, USA] or Spaxus [Taewoong Medical Co, Gimpo, Korea]) for EUS-BD and EUS-GB. The outcomes of interest were technical success, clinical success, and adverse events. Pooled proportions along with 95% confidence intervals were calculated.

RESULTS

A total of 18 observational studies were included: 11 for the Axios stent (433 patients; mean age, 72 years; 54% male) and 7 for the Spaxus stent (242 patients; mean age, 74 years; 50% male). The respective pooled outcomes for the Axios stent (EUS-BD and EUS-GB, respectively) were technical success, 96.2% and 96.2%; clinical success, 92.8% and 92.7%; total adverse events, 10.1% and 23.6%; and bleeding, 3.7% and 4.8%. The respective pooled outcomes for the Spaxus stent (EUS-BD and EUS-GB, respectively) were technical success, 93.8% and 95.9%; clinical success, 90.1% and 94.2%; total adverse events, 12.6% and 9.5%; and bleeding, 3.1% and 1.8%.

CONCLUSIONS

Axios and Spaxus stents demonstrate similar pooled technical and clinical success rates. Adverse events occurred in 23.6% of patients (Axios stent) and 9.5% of patients (Spaxus stent) during EUS-GB.

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.

Lumen-apposing metal stents (with videos)

BACKGROUND AND AIMS

Lumen-apposing metal stents (LAMSs) are a novel class of devices that have expanded the spectrum of endoscopic GI interventions. LAMSs with their dumbbell configuration, short saddle length, and large inner luminal diameter provide favorable stent characteristics to facilitate anastomosis formation between the gut lumen and adjacent structures.

METHODS

The MEDLINE database was searched through April 2021 for articles related to LAMSs by using additional relevant keywords such as "walled-off pancreatic necrosis," "pseudocysts," "pancreatic fluid collection," "cholecystitis," "gastroenterostomy," in addition to "endoscopic treatment" and "endoscopic management," among others.

RESULTS

This technology review describes the full spectrum of LAMS designs and delivery systems, techniques for deployment, procedural outcomes, safety, training issues, and financial considerations.

CONCLUSIONS

Although LAMSs were initially introduced for drainage of pancreatic pseudocysts and walled-off necrosis, the versatility of these devices has led to a variety of off-label uses including gallbladder drainage, enteric bypass with the creation of gastroenterostomies, and treatment of luminal GI strictures.