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Stent implantation into the tracheo-bronchial system in rabbits: histopathologic sequelae in bare metal vs. drug-eluting stents.

Sigler M, Klötzer J, Quentin T, Paul T, Möller O - Mol Cell Pediatr (2015)

Bottom Line: After stent implantation in the tracheo-bronchial system of rabbits, we found tissue reactions comparable to those seen after stent implantation into the vascular system.We found, however, a significantly different inflammatory reaction with a more pronounced foreign-body reaction in sirolimus-coated stents.In our small series, drug-eluting stents did not exhibit any benefit over bare metal stents in an experimental setting.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatric Cardiology and Intensive Care Medicine, University Medical Center, Georg August University Göttingen, Robert Koch Strasse 40, D 37075, Göttingen, Germany. msigler@gwdg.de.

ABSTRACT

Background: Stent implantation into the tracheo-bronchial system may be life-saving in selected pediatric patients with otherwise intractable stenosis of the upper airways. Following implantation, significant tissue proliferation may occur, requiring re-interventions. We sought to evaluate the effect of immunosuppressive coating of the stents on the extent of tissue proliferation in an animal model.

Methods: Bare metal and sirolimus-coated stents (Bx Sonic and Cypher Select, Johnson & Johnson, Cordis) were implanted into non-stenotic lower airways of New Zealand white rabbits (weight 3.1 to 4.8 kg). Three stents with sirolimus coating and six bare metal stents could be analyzed by means of histology and immunohistochemistry 12 months after implantation.

Results: On a macroscopic evaluation, all stents were partially covered with a considerable amount of whitish tissue. Histologically, these proliferations contained fiber-rich connective tissue and some fibromuscular cells without significant differences between both stent types. The superficial tissue layer was formed by typical respiratory epithelium and polygonal cells. Abundant lymphocyte infiltrations and moderate granulocyte infiltrations were found in both groups correspondingly, whereas foreign-body reaction was more pronounced around sirolimus-eluting stents.

Conclusions: After stent implantation in the tracheo-bronchial system of rabbits, we found tissue reactions comparable to those seen after stent implantation into the vascular system. There was no difference between coated and uncoated stents with regard to quality and quantity of tissue proliferation. We found, however, a significantly different inflammatory reaction with a more pronounced foreign-body reaction in sirolimus-coated stents. In our small series, drug-eluting stents did not exhibit any benefit over bare metal stents in an experimental setting.

No MeSH data available.


Related in: MedlinePlus

Richardson blue staining of stent struts (black structures) with local inflammatory reactions: granulocyte infiltration (arrows) locally related to a bare metal stent (a); lymphocytic infiltration (arrows) locally related to a sirolimus-eluting stent (b); only a few histiocytes/macrophages (arrow) locally related to a bare metal stent (c); multiple macrophages/histiocytes (light arrows) and foreign-body giant cells (bold arrows) locally related to a sirolimus-eluting stent (d)
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Fig3: Richardson blue staining of stent struts (black structures) with local inflammatory reactions: granulocyte infiltration (arrows) locally related to a bare metal stent (a); lymphocytic infiltration (arrows) locally related to a sirolimus-eluting stent (b); only a few histiocytes/macrophages (arrow) locally related to a bare metal stent (c); multiple macrophages/histiocytes (light arrows) and foreign-body giant cells (bold arrows) locally related to a sirolimus-eluting stent (d)

Mentions: Dense infiltrations of inflammatory cells were found in all specimens (Table 1). Granulocytes were located predominantly around the stent struts (Fig. 3a), infiltrating the respiratory epithelium (Fig. 2e). Lymphocyte infiltrations showed an irregular distribution pattern through all layers of the airway wall (Fig. 3b). Histiocytes (macrophages) were present in all specimens as well (Fig. 3c), but with a significant accumulation locally related to stent struts of sirolimus-eluting stents. Formation of multiple foreign-body giant cells was also found more pronounced in these stents correspondingly (Fig. 3d).Fig. 3


Stent implantation into the tracheo-bronchial system in rabbits: histopathologic sequelae in bare metal vs. drug-eluting stents.

Sigler M, Klötzer J, Quentin T, Paul T, Möller O - Mol Cell Pediatr (2015)

Richardson blue staining of stent struts (black structures) with local inflammatory reactions: granulocyte infiltration (arrows) locally related to a bare metal stent (a); lymphocytic infiltration (arrows) locally related to a sirolimus-eluting stent (b); only a few histiocytes/macrophages (arrow) locally related to a bare metal stent (c); multiple macrophages/histiocytes (light arrows) and foreign-body giant cells (bold arrows) locally related to a sirolimus-eluting stent (d)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4635111&req=5

Fig3: Richardson blue staining of stent struts (black structures) with local inflammatory reactions: granulocyte infiltration (arrows) locally related to a bare metal stent (a); lymphocytic infiltration (arrows) locally related to a sirolimus-eluting stent (b); only a few histiocytes/macrophages (arrow) locally related to a bare metal stent (c); multiple macrophages/histiocytes (light arrows) and foreign-body giant cells (bold arrows) locally related to a sirolimus-eluting stent (d)
Mentions: Dense infiltrations of inflammatory cells were found in all specimens (Table 1). Granulocytes were located predominantly around the stent struts (Fig. 3a), infiltrating the respiratory epithelium (Fig. 2e). Lymphocyte infiltrations showed an irregular distribution pattern through all layers of the airway wall (Fig. 3b). Histiocytes (macrophages) were present in all specimens as well (Fig. 3c), but with a significant accumulation locally related to stent struts of sirolimus-eluting stents. Formation of multiple foreign-body giant cells was also found more pronounced in these stents correspondingly (Fig. 3d).Fig. 3

Bottom Line: After stent implantation in the tracheo-bronchial system of rabbits, we found tissue reactions comparable to those seen after stent implantation into the vascular system.We found, however, a significantly different inflammatory reaction with a more pronounced foreign-body reaction in sirolimus-coated stents.In our small series, drug-eluting stents did not exhibit any benefit over bare metal stents in an experimental setting.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatric Cardiology and Intensive Care Medicine, University Medical Center, Georg August University Göttingen, Robert Koch Strasse 40, D 37075, Göttingen, Germany. msigler@gwdg.de.

ABSTRACT

Background: Stent implantation into the tracheo-bronchial system may be life-saving in selected pediatric patients with otherwise intractable stenosis of the upper airways. Following implantation, significant tissue proliferation may occur, requiring re-interventions. We sought to evaluate the effect of immunosuppressive coating of the stents on the extent of tissue proliferation in an animal model.

Methods: Bare metal and sirolimus-coated stents (Bx Sonic and Cypher Select, Johnson & Johnson, Cordis) were implanted into non-stenotic lower airways of New Zealand white rabbits (weight 3.1 to 4.8 kg). Three stents with sirolimus coating and six bare metal stents could be analyzed by means of histology and immunohistochemistry 12 months after implantation.

Results: On a macroscopic evaluation, all stents were partially covered with a considerable amount of whitish tissue. Histologically, these proliferations contained fiber-rich connective tissue and some fibromuscular cells without significant differences between both stent types. The superficial tissue layer was formed by typical respiratory epithelium and polygonal cells. Abundant lymphocyte infiltrations and moderate granulocyte infiltrations were found in both groups correspondingly, whereas foreign-body reaction was more pronounced around sirolimus-eluting stents.

Conclusions: After stent implantation in the tracheo-bronchial system of rabbits, we found tissue reactions comparable to those seen after stent implantation into the vascular system. There was no difference between coated and uncoated stents with regard to quality and quantity of tissue proliferation. We found, however, a significantly different inflammatory reaction with a more pronounced foreign-body reaction in sirolimus-coated stents. In our small series, drug-eluting stents did not exhibit any benefit over bare metal stents in an experimental setting.

No MeSH data available.


Related in: MedlinePlus