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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: Abundant lymphocyte infiltrations and moderate granulocyte infiltrations were found in both groups correspondingly, whereas foreign-body reaction was more pronounced around sirolimus-eluting stents.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

Stent strut (black structure, a) surrounded by mostly spindle-shaped cells embedded in fiber-rich connective tissue (bare metal stent; Richardson blue staining); immunohistochemical staining (brown coloring) with antibodies against smooth muscle myosin (b; bare metal stent), vimentin (c; sirolimus-eluting stent), and smooth muscle actin (d; bare metal stent) identifying the spindle-shaped cells as fibromuscular cells; newly formed epithelium with polygonal cells lining the tracheo-bronchial lumen (e; bare metal stent; Richardson blue staining); cartilage structure within the newly formed tissue (f, arrows; sirolimus-eluting stent; Richardson blue staining)
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Fig2: Stent strut (black structure, a) surrounded by mostly spindle-shaped cells embedded in fiber-rich connective tissue (bare metal stent; Richardson blue staining); immunohistochemical staining (brown coloring) with antibodies against smooth muscle myosin (b; bare metal stent), vimentin (c; sirolimus-eluting stent), and smooth muscle actin (d; bare metal stent) identifying the spindle-shaped cells as fibromuscular cells; newly formed epithelium with polygonal cells lining the tracheo-bronchial lumen (e; bare metal stent; Richardson blue staining); cartilage structure within the newly formed tissue (f, arrows; sirolimus-eluting stent; Richardson blue staining)

Mentions: Histologically, significant proliferation of tissue was found in all specimen around the stent struts (Fig. 1a–d). The proliferations consisted of spindle-shaped cells with the typical morphologic appearance of fibromuscular cells surrounded by fiber-rich connective tissue (Fig. 2a). On immunostaining, fibromuscular cells showed the typical staining pattern with antibodies against smooth muscle myosin (Fig. 2b), smooth muscle actin (Fig. 2c), and Vimentin, a marker for cells of mesenchymal origin (Fig. 2d). There was no difference in quantity or quality of granulation tissue between the two groups of uncoated vs. sirolimus-coated stents (Table 1).Fig. 1


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)

Stent strut (black structure, a) surrounded by mostly spindle-shaped cells embedded in fiber-rich connective tissue (bare metal stent; Richardson blue staining); immunohistochemical staining (brown coloring) with antibodies against smooth muscle myosin (b; bare metal stent), vimentin (c; sirolimus-eluting stent), and smooth muscle actin (d; bare metal stent) identifying the spindle-shaped cells as fibromuscular cells; newly formed epithelium with polygonal cells lining the tracheo-bronchial lumen (e; bare metal stent; Richardson blue staining); cartilage structure within the newly formed tissue (f, arrows; sirolimus-eluting stent; Richardson blue staining)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig2: Stent strut (black structure, a) surrounded by mostly spindle-shaped cells embedded in fiber-rich connective tissue (bare metal stent; Richardson blue staining); immunohistochemical staining (brown coloring) with antibodies against smooth muscle myosin (b; bare metal stent), vimentin (c; sirolimus-eluting stent), and smooth muscle actin (d; bare metal stent) identifying the spindle-shaped cells as fibromuscular cells; newly formed epithelium with polygonal cells lining the tracheo-bronchial lumen (e; bare metal stent; Richardson blue staining); cartilage structure within the newly formed tissue (f, arrows; sirolimus-eluting stent; Richardson blue staining)
Mentions: Histologically, significant proliferation of tissue was found in all specimen around the stent struts (Fig. 1a–d). The proliferations consisted of spindle-shaped cells with the typical morphologic appearance of fibromuscular cells surrounded by fiber-rich connective tissue (Fig. 2a). On immunostaining, fibromuscular cells showed the typical staining pattern with antibodies against smooth muscle myosin (Fig. 2b), smooth muscle actin (Fig. 2c), and Vimentin, a marker for cells of mesenchymal origin (Fig. 2d). There was no difference in quantity or quality of granulation tissue between the two groups of uncoated vs. sirolimus-coated stents (Table 1).Fig. 1

Bottom Line: Abundant lymphocyte infiltrations and moderate granulocyte infiltrations were found in both groups correspondingly, whereas foreign-body reaction was more pronounced around sirolimus-eluting stents.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