The research design is a randomized prospective clinical trial comparing Endoscopic ultrasound (EUS) guided drainage of WON using FCSEMS and plastic stents. The trial will be conducted at the Florida Hospital Center for Interventional Endoscopy, Orlando, Florida.

The research design is a randomized prospective clinical trial comparing EUS-guided drainage of WON using FCSEMS and plastic stents. The trial will be conducted at the Florida Hospital Center for Interventional Endoscopy, Orlando, Florida.The sample size estimated for this study is 60 patients. All patients will undergo EUS-guided drainage of WON and be randomized to either FCSEM or plastic stents in a 1:1 ratio using a computer-generated randomized sequence. It will not be possible to blind the endoscopist to the stent type being inserted due to the differences in stent appearance. The statistician will be blinded to the stent type utilized.

Inclusion Criteria:

1. The subject (or when applicable the subject's LAR) is capable of understanding and complying with protocol requirements.

2. The subject (or when applicable the subject's LAR) is able to understand and willing to sign an informed consent form prior to the initiation of any study procedures.

3. Males or females ≥ 18 years of age.

4. WON diagnosed on contrast-enhanced dual phase CT abdomen/pelvis (CECT) or MRI with gadolinium (seen as a fluid collection in the setting of documented pancreatic necrosis that contains necrotic material and encased within a well-defined tissue layer).

5. WON of any size with any quantity of solid/necrotic component and any no. of loculations, located within the pancreatic/peri-pancreatic space not requiring percutaneous drainage, within 2cm of the enteric wall

6. Suspected/confirmed infected WON (defined as temp ≥ 100.5°F, serum White Blood Cells ≥ 15x109/L, positive blood cultures or positive Gram stain/culture of aspirated necrotic material), and/or symptomatic WON (defined as abdominal pain, gastric/intestinal/biliary outlet obstruction resulting in nausea, vomiting, early satiety, jaundice, or persistent malaise) ≥ 4 weeks from attack of acute pancreatitis.

7. Documented history of acute or chronic pancreatitis:

   i. Acute pancreatitis is diagnosed if 2 of the following 3 criteria are met:

   1. Abdominal pain characteristic of acute pancreatitis
   2. Serum lipase/amylase ≥ x3 upper limit of normal
   3. Characteristic radiological findings of acute pancreatitis on CECT/MRI/US abdomen, such as homogeneous enhancement of pancreatic parenchyma, standing of peripancreatic fat ii. Chronic pancreatitis is diagnosed if characteristic radiological changes are seen on CT/MRI with Magnetic resonance cholangiopancreatography (MRCP) (such as pancreatic atrophy, dilated pancreatic duct, pancreatic calcification) or EUS (≥5/9 of Rosement criteria)

8. Able to undergo general anesthesia

Exclusion Criteria:

1. Females who are pregnant or lactating. Pregnancy for females of childbearing potential will be determined by routine preoperative urine or serum Human Chorionic Gonadotropin testing.
2. Irreversible coagulopathy (INR >1.5, thrombocytopenia with platelet count <50,000/mL)
3. Has surgically altered gastrointestinal anatomy such as but not limited to Billroth II, Roux-en-Y, gastric bypass
4. Age < 18 years
5. Unable to obtain consent for the procedure from either the patient or LAR
6. Use of anticoagulants that cannot be discontinued for the procedure
7. Unable to tolerate general anesthesia
8. WON that is not accessible for EUS-guided drainage
9. Percutaneous drainage of WON is required or performed prior to EUS-guided drainage