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

Molecular and Cellular Pediatrics

Table 1 Experimental animals and histology results

Number	Stent type	Weight at implant	Number of re-dilatations	Time of re-dilatation	Histology results
Number	Stent type	Grams	Number of re-dilatations	Time of re-dilatation	Proliferation^a	Granulocytes^b	Lymphocytes^b	Histocytes/FBR^b
1	Bx Sonic	4.300	1	1 month	+	++	++	+
2	Bx Sonic	4.170	1	6 months	+	++	++	+
3	Bx Sonic	3.900	1	1 month	+	++	++	+
4	Bx Sonic	4.000	1	1 month	++	+	++	+
5	Bx Sonic	4.300	1	1 month	+	++	++	+
6	Bx Sonic	4.700	1	1 month	+	++	++	+
7	Cypher Select	4.760	1	1 month	+	++	++	+++
8	Cypher Select	4.310	1	6 months	+	+	+	++
9	Cypher Select	4.110	1	1 month	+	++	++	+++

FBR foreign-body reaction
^aGrading of the extent of granulation tissue with the lumen of the stents: 0 – no proliferation; + − lumen obstruction 1–25 %; ++ − lumen obstruction 26–50 %; +++ − lumen obstruction >50 %
^bGrading of inflammatory reactions describing the presence of different cell types around the stent struts: 0 – no inflammatory cells; + − light, noncircumferential infiltrate; ++ − localized, moderate to dense cellular aggregate; +++ − circumferential, dense cell infiltration