A Multi-Center, Prospective Study of the Wall Flex ® RX Biliary Fully Covered Stent for the Treatment of Benign Biliary strictures

This study will Assess the safety and performance of temporary placement of the
Wall Flex ® Biliary RX as a Fully Covered Stent Treatment of Biliary
obstruction that result from benign bile duct strictures.

  Obstruction of the bile duct may be caused by benign or malignant Biliary
strictures. Benign strictures may result from pancreatic disease, postoperative
complications, sclerosing cholangitis and a variety of rarer causes.

  Benign and malignant Biliary strictures are commonly managed endoscopically
by endoscopic retrograde cholangiopancreatography (ERCP) with or without
balloon Dilation, sphincterotomy, and stent placement.

  Stents may be placed endoscopically in patients with malignant or benign
Obstructions for long-term palliation or as temporary therapy. Plastic stents
have been used for treatment of post-liver transplantation and cholecystectomy
bile leaks, bile duct stones, and benign bile duct strictures. It is
anticipated that these stents will occlude over time, and most physicians will
exchange the stent as needed, or will routinely exchange them at 3-month
intervals.

  Benign Biliary strictures may be diagnosed with computed tomography (CT) and
ultrasound, however, endoscopic ultrasound (EUS) and ERCP have become the more
reliable diagnostic tools. Limited data are available comparing endoscopic and
surgical treatments for benign Biliary strictures. Repeat surgery, however, is
reported to have 10% mortality and 10% -30% stricture recurrence rates6.
Successful treatment of post-operative Biliary strictures (POBS) correlates to
the time of diagnosis following injury, and therapy may include surgery,
percutaneous transhepatic and endoscopic techniques.
  Endoscopic treatment using temporary placement of plastic stents provides a
proven therapeutic alternative for Biliary obstruction secondary to benign bile
duct strictures. In this minimally invasive approach, the bile duct stricture
is calibrated by successive placement of plastic stents, increasing, where
possible, the number of stents at each stent exchange over several months to
the goal of a stent-free product. This requires numerous ERCP procedures,
typically three or more over numerous months. In general, the treatment goals
are improvement in cholestasis, long-term absence of symptoms and Eradication
of the stricture9.
  • Post Operative Biliary strictures: Injury Associated With Biliary surgery
may result in leakage of bile from minor or major bile ducts, bile duct
stenosis with or without leakage, or transection of the bile duct10. Management
of post-operative Biliary strictures includes surgery with Roux-en-Y
hepaticojejunostomy and / or treatment with percutaneous transhepatic
dilatation and percutaneous drain placement. However, surgery is associated
with morbidity, including a 10% -30% stricture recurrence rate11. Endoscopic
treatment is becoming the first approach to treatment and is more likely to be
successful if commenced early after the time of injury5, 6,8,10,12. According
to Bergman et AL10 goal of the initial endoscopic treatment is to remodel the
bile duct.
  • Liver Transplantation: Complications from liver transplant may include
Biliary leaks, anastomotic strictures and associated cholangitis5. Surgery is
often the primary treatment method but carries significant risk and the need
for retransplantation. Many of these patients experience or intrahepatic
strictures that are recurring, which make surgery more difficult and less
effective13.
  • Chronic Pancreatitis: Incidence of strictures that result from chronic
pancreatitis is reported between 3% -23% 15. Studies reviewed by Eickoff et
al16 indicate that strictures caused by chronic pancreatitis may result in
cholestasis, cholangitis, and Jaundice. Surgical drainage and endscopic therapy
including stenting are the most common treatment methods. Vitale et al17
reported 80% success of stenting for chronic pancreatitis stenting with an
average period of 13 months. Eickoff et al18 reported 46% of stricture
regression and clinical improvement after a median stenting period of 9 months.

  The placement of self-expanding metal stents (SEMS) in the bile duct for
benign disease is becoming more common. Although literature does not document
results of Removability metal stent in a prospective, controlled clinical
trial, the presence of case reports and retrospective analysis of literature
demonstrates that Removability metal stent is feasible. A review of 20 clinical
study publications documents 310 metal stent removal attempts, 232 of which
were from benign strictures. Duration of indwelling stent ranged from 0-28
months with stent removal reported as feasible in 90% of the cases. Severe
complications reported include painful extraction, bile leak, bleeding, pain
and ERCP-related pancreatitis.

Primary Objective: To assess the safety and performance of temporary placement
of the Wall Flex Biliary RX as a Fully Covered Stent Treatment of Biliary
obstruction that result from benign bile duct strictures.

The study is designed as a multi-center, prospective, non-randomized study. Ten
to 15 sites will participate, and enrollment of 187 patients is planned. The
proposed duration of the study is approximately 7 years 12 months for allo wing
enrollment / treatment plus 6 years to complete follow-up. Patients will be
followed for 5 years after stent removal.

Patients who are consented and meet inclusion / exclusion criteria will undergo
a stenting procedure with the Wall Flex Fully Covered Biliary RX Stent System.
  The stent will remain in patients from the post-liver transplant cohort for 5
months (plus / minus 1 month) at which point it will be removed. The stent will
remain in the form chronic pancreatitis patients and post-abdominal surgery
cohorts for 11 months (plus / minus 1 months) at which point it will be
removed.

Potential Complication Associated with Metal Stent Placement
  o Pain
  o Bleeding
  o Fever
  o Nausea
  o Vomiting
  o Infection
  o Inflammation
  o Recurrent Obstructive Jaundice
  o Stent occlusion
  o Stent fracture
  o Mucosal hyperplasia
  o cholangitis
  o Cholecystitis *
  o Pancreatitis
  o ulceration and perforation of duodenal or bile duct
  o Stent migration
  o Death
  o Stent misplacement
  o Perforation of the gallbladder due to the stent covering the cystic duct *
  * Note: In a small clinical trial of this device, two out of four (50%)
subjects who had a stent placed across the cystic duct developed cholecystitis.
One of these subjects Suffered a perforated gallbladder due to the stent
covering the cystic duct, requiring a drain to be placed.
  o Hepatic abscess
  o Retransplant

  Potential Complications Associated with Stent Removal (additional to those
listed above)
  o Abscess with fistula formation
  o Wire mesh disruption
  o Duodenal edema
  o Stent wall embedment in CBD
  o Bile leak