Jorge Lopera MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: To report the results of a comparative study for migration rates, tissue reaction, and retrievability, between fully covered, partially covered, and uncovered stents, in the normal trachea of the swine. Methods and Materials: Seventeen pigs (weight 25-29 kg) were divided into three groups:Group 1: Uncovered (U)(n=6), Group 2: Partially Covered (PC)(n=6), and Group 3: Fully Covered (FC)(n=5)tracheal stents. The stents were made with nitinol wire and covered with a polyurethane membrane. A nylon loop was placed at the proximal end of the stents to allow retrieval. The stents were placed in the distal trachea under fluoroscopy. Follow-up chest radiography and bronchoscopy were performed at 1 week, 1 month, and 2 months after the procedure. Removal of all stents was attempted two months after placement. Bronchoscopy was performed immediately and one week after retrieval to evaluate intratracheal mucosal changes within the trachea. One week following retrieval, the animals were euthanized and the tracheas were harvested for pathology. Results: Three pigs (2 PC,1 U) were sacrificed due to severe pneumonia. Migration rates: U stents: slight 1/6,moderate 1/6. PC stents: slight 1/6, severe 1/6. FC stents: moderate 2/5,severe 3/5. Retrievability: U stents 0/5. PC stents 2/3. FC stents 3/4. All removed stents maintained structural integrity, all pigs survived until sacrifice one week after retrieval. Tissue reaction: U stents:mild 1/6, moderate 3/6, severe 2/6. PC stents: moderate 1/6. FC : moderate 1/6. Significant amounts of mucous retaining were found in FC stents, moderate in PC stents, and minimal in U stents. Conclusion: In the normal trachea of the swine after two months: Uncovered stents have the lowest migration rates but cannot be removed due to granulation tissue. Fully covered stents can be retrieved in most animals but have a high migration rate. Partially covered stents have an intermediate rate of migration and can be retrieved. Although most of the partially covered and fully covered stents can be retrieved, granulation tissue near the ends of the stents may also prevent retrieval.       Questions about this event email: jloper@lsuhsc.edu

Lopera MD, J, Comparison between Uncovered, Fully-covered, and Partially-covered Stents in the Normal Trachea of the Swine.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3105121.html