Safety and Efficacy of the New 20 mm Lumen Apposing Metal Stent (Lams) for Endoscopic Treatment of Pancreatic and Peripancreatic Fluid Collections

Pancreatic fluid collections (PFC) can occur as a complication of acute and chronic pancreatitis. PFC include pancreatic pseudocysts (PP) and walled-off necrosis (WON). The majorities of WON are asymptomatic and will resolve spontaneously. Endoscopic ultrasound (EUS)-guided drainage has become the preferred treatment in the management of symptomatic PFC, with significant advantages compared with surgical and percutaneous drainage. Successful endoscopic management of the pancreatic fluid collections depends on the type of PFC. Studies have shown that endoscopic drainage of PP is greater than 90%, while success for WON is at best between 50-65%. Differences in treatment outcome are attributed to the viscosity and debris content of the PFC. Traditionally, the EUS-guided drainage has been performed with placement of multiple plastic stents or fully covered self-expanding metal stent. Recently, lumen-apposing metal stents (LAMS) have been developed. LAMS have been utilized for the access and drainage of pancreatic fluid collections (PFCs). To date, a variety of LAMS sizes have been commercially available and widely used. Studies have shown high technical success (89-100%) and high clinical success rate (93-100%). The larger diameter of LAMS facilitates better drainage of PFC contents when compared to the small caliber of plastic stents and allows necrosectomy in repeated sessions without the need for stent replacement. A new LAMS with a larger (20mm) lumen diameter (the Hot Axios, Boston Scientific, Natick MA, USA) was released on the market, with the idea that a larger diameter would allow a faster drainage of PFCs and facilitate endoscopic necrosectomy. This is currently the largest diameter LAMS available. Further studies are needed to determine the ideal size for a LAMS going forward to achieve maximal clinical benefit with minimal patient risk. Aim of the investigator's study is to evaluate the safety and efficacy of the new 20 mm Hot Axios stent placement for EUS-guided transmural drainage of pancreatic fluid collections.

Pancreatic fluid collections (PFC) can occur as a complication of acute and chronic pancreatitis. PFC include pancreatic pseudocysts (PP) and walled-off necrosis (WON). The majorities of WON are asymptomatic and will resolve spontaneously. Endoscopic ultrasound (EUS)-guided drainage has become the preferred treatment in the management of symptomatic PFC, with significant advantages compared with surgical and percutaneous drainage. Successful endoscopic management of the pancreatic fluid collections depends on the type of PFC. Studies have shown that endoscopic drainage of PP is greater than 90%, while success for WON is at best between 50-65%. Differences in treatment outcome are attributed to the viscosity and debris content of the PFC. Traditionally, the EUS-guided drainage has been performed with placement of multiple plastic stents or fully covered self-expanding metal stent. Recently, lumen-apposing metal stents (LAMS) have been developed. LAMS have been utilized for the access and drainage of pancreatic fluid collections (PFCs). To date, a variety of LAMS sizes have been commercially available and widely used. Studies have shown high technical success (89-100%) and high clinical success rate (93-100%). The larger diameter of LAMS facilitates better drainage of PFC contents when compared to the small caliber of plastic stents and allows necrosectomy in repeated sessions without the need for stent replacement. A new LAMS with a larger (20mm) lumen diameter (the Hot Axios, Boston Scientific, Natick MA, USA) was released on the market, with the idea that a larger diameter would allow a faster drainage of PFCs and facilitate endoscopic necrosectomy. This is currently the largest diameter LAMS available. Further studies are needed to determine the ideal size for a LAMS going forward to achieve maximal clinical benefit with minimal patient risk. Aim of the investigator's study is to evaluate the safety and efficacy of the new 20 mm Hot Axios stent placement for EUS-guided transmural drainage of pancreatic fluid collections.