What is a Lumen Apposing Metal Stent (LAMS)?

From the Guidelines

Lumen apposing metal stents (LAMS) should be used for endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) in patients with acute cholecystitis who are poor surgical candidates, as they offer high rates of technical and clinical success and low rates of adverse events, as demonstrated in a recent study 1.

Key Points

• LAMS are specialized self-expanding metal stents designed to create a connection between two adjacent hollow organs or between a hollow organ and a fluid collection.
• They feature wide flanges at both ends that secure the stent in place, preventing migration while maintaining a short body length to keep the connected structures in close apposition.
• LAMS are primarily used in endoscopic procedures for drainage of pancreatic fluid collections, gallbladder drainage in patients unfit for surgery, and creation of gastrojejunostomy for gastric outlet obstruction.
• The stents typically range from 10-20mm in diameter and are deployed under endoscopic ultrasound guidance.
• LAMS provide advantages over traditional plastic stents, including larger diameter for better drainage, decreased risk of leakage, and reduced migration rates, as noted in a study 1.

Advantages and Disadvantages

• Advantages of LAMS include high rates of technical and clinical success, low rates of adverse events, and the ability to provide minimally invasive alternatives to traditional surgical approaches.
• Disadvantages of LAMS include higher costs and potential complications, such as bleeding, perforation, and buried stent syndrome, as reported in a study 1.

Clinical Use

• LAMS are recommended for use in EUS-GBD in patients with acute cholecystitis who are poor surgical candidates, as they offer a safe and effective alternative to traditional surgical approaches, as stated in a clinical practice update 1.
• The use of LAMS in other clinical settings, such as pancreatic fluid collection drainage and gastrojejunostomy creation, may also be beneficial, but further studies are needed to confirm their efficacy and safety in these settings.

From the Research

Lumen Apposing Metal Stent (LAMS) Overview

• LAMS are used for endoscopic ultrasound-guided drainage of pancreatic fluid collections (PFCs) 2, 3, 4, 5, 6
• They have a larger diameter compared to plastic stents and can be inserted in a single step, reducing the need for repeat access 2
• LAMS have been shown to be safe and effective, with high clinical and technical success rates, and a low risk of complications such as perforation, peritoneal leakage, and migration 2, 3, 5, 6

Advantages of LAMS

• Single-step deployment 2
• Ability to perform endoscopic debridement with minimal stent migration 2
• High clinical success rates, with resolution of PFCs in 91-93% of patients 2, 5
• Low major complication rates, ranging from 5-15% 2, 5, 6

Clinical Applications of LAMS

• Drainage of pancreatic pseudocysts and walled-off necrosis (WON) 2, 3, 4, 5, 6
• Endoscopic necrosectomy for WON 4, 5, 6
• Treatment of symptomatic PFCs, including those with infection or bleeding 3, 4, 5, 6

Removal Timing and Complications

• Removal timing of LAMS is still a topic of debate, with limited literature available 3
• Complications associated with LAMS removal include stent migration, dislodgement, and infection 2, 3, 5, 6
• Major adverse events, such as perforation and massive bleeding, are rare but can occur 5, 6