Objective: To present technique and results of a microvascular denudation of the common femoral artery of the mouse as a model for inducing intimal hyperplasia in interventional radiology.
Materials and methods: Under general anesthesia introduced by intraperitoneal injection, 14 B6129F1 hybrid mice (7 females and 7 males) at a mean age of 12.1 +/- 1.8 weeks and a mean weight of 28 +/- 2.8 grams had a groin incision of the vascular bundle directly distal to the inguinal ligament in preparation of placing a vascular clamp. Thereafter, the femoral artery was dissected distal to the origin of the epigastric artery and a loop prepared for a ligation proximal to the planned arteriotomy. Through an arteriotomy performed free-hand with a pair of micro scissors, a 0.010" (= 0.25 mm) guidewire was introduced into the vessel and advanced to the aortic bifurcation. The guide-wire was moved back and forth three times. The same procedure was performed on the other side as sham-operation, i.e., without introduction and passage of a guidewire. The resulting changes of the vessel wall were evaluated by histology and morphometry.
Results: Four weeks after intervention, the mean intima-to-media-ratio (IMR) was 1.80 +/- 0.28. A significant difference was observed between the sexes, with an IMR of 1.41 +/- 0.29 in females and an IMR of 2.24 +/- 0.45 in males (p = 0.0173). The neointima led to an overall luminal loss of 50.2% +/- 8.3% without significant sex difference (p = 0.09), but the average luminal loss was still more severe in females, amounting to 43.9% in comparison to 56.1% in males. This technique induces a significant neointima formation in a reproducible manner. The internal elastic membrane was preserved in all vessels.
Conclusion: This technique is an excellent model to examine the differences between genetically modified mice to clarify the role of putative key molecules in the pathophysiology of restenosis.