Covered Versus Uncovered Self-expandable Metallic Stents for Malignant Gastric Outlet Obstruction
Condition: Gastric Outlet Obstruction Due to Gastric Adenocarcinoma
MeSH terms: Gastric Outlet Obstruction; Pyloric Stenosis
Study type: Interventional
Phase: Phase 3

Summary: 
      Malignant gastric outlet obstruction can result from gastric adenocarcinoma, leading to
      intractable vomiting, nausea, and poor oral food intake. Although self-expandable metallic
      stent (SEMS) insertion has excellent technical and clinical success rates for relieving
      gastric outlet obstruction symptoms, the uncovered SEMS is susceptible to re-stenosis because
      of tumor ingrowth through openings between the stent wire filaments. Therefore, the most
      common reason for stent failure in uncovered stents is tumor ingrowth.

      The covered SEMS has a membrane that prevents ingrowth through the mesh wall and consequently
      shows lower rate of re-stenosis than uncovered SEMS. However, covered SEMS has a higher risk
      of stent migration compared to uncovered SEMS. Recent prospective, randomized study showed
      that there was no significant difference between uncovered and covered SEMS in terms of stent
      patency rate as well as technical and clinical success rates.

      Recently the investigators developed new covered SEMS for gastric outlet obstruction. This
      new covered SEMS has features that may contribute to reducing migration rate: 1) partially
      covered design; 2)less radial force in central portion of stent; 3) presence of lasso which
      enable position of stent to be adjusted after deployment; 4)presence of protrusion in both
      sides of stent. This prospective, randomized study aimed to compare the effectiveness and
      side effects of newly developed covered SEMS with those of uncovered SEMS in patients with
      malignant gastric outlet obstruction from gastric cancer.
    


Intervention name(s): Covered stent (Bona stent pyloric/duodenal covered) insertion; Uncovered stent (Bona stent, pyloric/duodenal) insertion
Intervention type(s): Device; Device
Intervention description(s): self-expandable metallic stent placement was performed with a therapeutic endoscope (working channel ≥ 3.7 mm) using a through-the-scope method. All patients underwent procedures under conscious sedation with midazolam and pethidine. The length of the stricture was assessed either endoscopically or fluoroscopically; the length of the stent had to exceed that of the stricture by at least 3 cm. After the required stent length was determined, the stent was advanced through the endoscope over a guidewire until it passed across the distal end of the stricture. Then, the stent was deployed under continuous fluoroscopic control. For the Wave covered stent group, the stent was repositioned after deployment using the lasso under fluoroscopic guidance (if necessary), aligning the central portion of the stricture with the central portion of the stent which had reduced radial force and indentation. Stent positioning was confirmed endoscopically and fluoroscopically.; Self-expandable metallic stent placement was performed with a therapeutic endoscope (working channel ≥ 3.7 mm) using a through-the-scope method. All patients underwent procedures under conscious sedation with midazolam and pethidine. The length of the stricture was assessed either endoscopically or fluoroscopically; the length of the stent had to exceed that of the stricture by at least 3 cm. After the required stent length was determined, the stent was advanced through the endoscope over a guidewire until it passed across the distal end of the stricture. Then, the stent was deployed under continuous fluoroscopic control. For the Wave covered stent group, the stent was repositioned after deployment using the lasso under fluoroscopic guidance (if necessary), aligning the central portion of the stricture with the central portion of the stent which had reduced radial force and indentation. Stent positioning was confirmed endoscopically and fluoroscopically.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment