Insertion of self-expandable nitinol stents without previous balloon angioplasty reduces restenosis compared with PTA prior to stenting.

PURPOSE

To compare the development of intimal hyperplasia after deployment of a self-expanding nitinol stent with and without previous percutaneous transluminal balloon angioplasty (PTA), with the results after PTA alone.

METHODS

In nine healthy pigs, the iliac arteries were divided into three groups: group 1 (n = 6 arteries) was treated with PTA; group 2 n = 6) with insertion of self-expanding stents after PTA; and group 3 (n = 6) with stent insertion without previous PTA. After 8 weeks the vessels were examined with intravascular ultrasonography, histologic examination and morphometric analysis.

RESULTS

Although the injury index in group 1 (0.17 +/- 0.57) was lower (p <0.05) than in group 2 (0.26 +/- 0.06) and group 3 (0.26 +/- 0.08), PTA-treated arteries showed significantly (p <0.05) reduced mean luminal gain (0.53 +/- 2.84) compared with arteries treated with PTA prior to stenting (2.58 +/- 1.38) and compared with stenting alone (4.65 +/- 5.34). Stenting after PTA resulted in a higher (p <0.05) restenosis index (2.63 +/- 1.06) compared with stenting without PTA (1.35 +/- 0.59). Group 2 also had a significantly thicker intima p <0.05) and 83% and 74% higher intima/media ratio (p <0.05) compared with groups 1 and 3, respectively.

CONCLUSION

Insertion of a self-expandable nitinol stent without previous PTA results in less intimal hyperplasia than if PTA is performed prior to stenting, suggesting that direct stenting can be used in angioplasty sessions with a favorable outcome.