Covered versus uncovered self-expandable metallic stents for palliation of malignant pyloric obstruction in gastric cancer patients: a randomized, prospective study

Gastrointest Endosc. 2010 Jul;72(1):25-32. doi: 10.1016/j.gie.2010.01.039. Epub 2010 Apr 9.


Background: Self-expandable metallic stents (SEMSs) provide effective palliation of malignant pyloric obstruction in patients with inoperable gastric cancer.

Objective: To compare the effectiveness and side effects of covered and uncovered SEMSs for the palliation of malignant pyloric obstruction.

Design: Prospective, randomized, single-center study.

Setting: Tertiary-care cancer center hospital.

Patients: This study involved 80 patients with pyloric obstruction related to inoperable gastric cancer.

Intervention: Covered or uncovered SEMS placement.

Main outcome measurements: Technical and clinical success rates as well as the patency rate at 8 weeks after placement.

Results: Both groups had a technical success rate of 100% with no immediate complications. Both groups also had comparable clinical success rates (covered SEMS, 95% [38 of 40] and uncovered SEMS, 90% [36 of 40], P = .68) and 8-week patency rates (covered SEMS, 61.3% [19 of 31] and uncovered SEMS, 61.1% [22 of 36], P > .99). Stent migration within 8 weeks was more common in the covered SEMS group (25.8% [8 of 31]) than in the uncovered SEMS group (2.8% [1 of 36], P = .009), whereas re-stenosis because of tumor ingrowth was more common in the uncovered SEMS group (25.0% [9 of 36] vs 0% [0 of 31] in the covered SEMS group, P = .003). Overall patient survival and stent patency did not differ between groups (P = .27 and 0.61 by log-rank test, respectively).

Limitations: The study population was limited to gastric cancer patients, and stent designs were changed in the midst of the study period.

Conclusion: Both the covered and uncovered SEMSs are effective and have comparable 8-week patency in patients with malignant pyloric obstruction, despite different patterns of late stent failure.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / pathology
  • Adenocarcinoma / therapy*
  • Adult
  • Aged
  • Aged, 80 and over
  • Cancer Care Facilities
  • Coated Materials, Biocompatible*
  • Equipment Design
  • Equipment Failure
  • Female
  • Foreign-Body Migration / etiology
  • Gastroscopy
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Palliative Care*
  • Prospective Studies
  • Pyloric Stenosis / therapy*
  • Recurrence
  • Stents*
  • Stomach Neoplasms / pathology
  • Stomach Neoplasms / therapy*


  • Coated Materials, Biocompatible