WallFlex Pancreatic Metal Stent for Pancreatic Duct Strictures

This study is a prospective, single arm, pre-approval study. Treatment of up to 92 patients will take place at up to 15 clinical centers. Patient who meet all eligibility criteria will receive the WallFlex Pancreatic stent for up to 6 months stent indwell and 6 months follow-up after stent removal.

Inclusion criteria

• Age 18 or older
• Willing and able to comply with study procedures and follow-up schedule and provide written informed consent to participate in study
• Chronic pancreatitis induced stricture of Cremer Type IV, namely distal dominant stricture with upstream ductal dilation.
• For patients with one prior plastic pancreatic stent: VAS Pain Score and Frequency of Pain sectors of the Izbicki pain scale at the time of placement of the plastic stent.
• Availability of narcotic dosage for at least one month prior to baseline visit for patients who do not have a prior plastic stent or availability for one month prior to placement of prior plastic stent, where applicable.
• VAS Pain Score of ≥ 20 before study stent placement for patients without a prior plastic pancreatic stent. VAS Pain Score of ≥ 20 before initial plastic pancreatic stent placement for patients with a prior plastic pancreatic stent indwelling for 90 days or less before study stent placement. VAS Pain Score is captured via Izbicki pain scale.
• Pain occurring weekly or more frequently (assessed by Frequency of Pain sector of the Izbicki pain scale) as reported before study stent placement for patients without a prior plastic pancreatic stent, or before placement of initial plastic pancreatic stent for patients with a prior plastic pancreatic stent indwelling for 90 days or less before study stent placement.
• Minimum 5 mm diameter of dilated duct immediately upstream of pancreatic duct stricture
• Prior clearance of pancreatic stones where needed

• If pancreatic duct stone clearance prior to placement of the study stent includes ESWL, then a plastic pancreatic stent may be placed immediately after the ESWL procedure at the discretion of the Investigator, for example, if there is concern about stone fragments of stone sludge in side branches of the pancreatic duct, and may be left indwelling for 30-90 days.
• If new pancreatic duct stones requiring ESWL have formed by the time of intended study stent placement, then the patient will not receive the study stent and be excluded from the study. Further treatment of the patient will be provided per standard of practice outside of the study. In case the study stent is not placed during the same session in which the plastic stent is removed, the pain score needs to be collected again prior to study stent placement.
• Prior endoscopic pancreatic sphincterotomy (EPS), historically or to be provided at time of SEMS placement as applicable.

Exclusion criteria

• Pancreatic or peri-ampullary cancer with or without pancreatic duct strictures caused by malignancy
• Biliary strictures caused by chronic pancreatitis that are symptomatic and/or in need of therapeutic intervention
• Perforated duct
• Ansa pancreatica
• Presence of pancreatic cysts suspected to be cystic tumor or requiring transmural drainage
• Duodenal/groove pancreatitis
• Autoimmune pancreatitis
• Pancreatic duct stenoses not located in the head of the pancreas
• Failed access during an attempted ERCP on a prior date at the investigational center
• Duration of indwell of one single plastic pancreatic stent or cumulative duration of consecutive single plastic pancreatic stents immediately prior to study stent placement exceeding 90 days
• History of prior single pancreatic plastic stent(s) followed by a stent-free period shorter than 1 year before enrollment into the study
• History of prior side-by-side multiple pancreatic plastic stents up to one year prior to enrollment
• History of prior pancreatic metal stent(s)
• Reported recent history of acute relapsing pancreatitis in the absence of chronic pancreatitis
• Patients for whom endoscopic techniques are contraindicated
• Patients who are currently enrolled in another investigational study that would directly interfere with the current study, without prior written approval from the sponsor
• Inability or refusal to comply with the follow-up schedule including patients living at such a distance from the investigational center that attending follow-up visits would be unusually difficult or burdensome