Key result
Aortic stenting increases proximal vascular distensibility and intimal lesion formation, while nitric oxide blockade augments intimal growth within but not proximal to the stent.
Why the study?
Does intravascular stenting alter adjacent vascular distensibility and neointima formation, and what is the role of nitric oxide in this process in a rabbit model?
Does intravascular stenting alter adjacent vascular distensibility and neointima formation, and what is the role of nitric oxide in this process in a rabbit model?
Aortic stenting alters adjacent vascular mechanics by increasing proximal distensibility and intimal lesion formation, a process modulated by nitric oxide.
Stent effects on adjacent vessels in rabbits should not change practice; leaves open nitric oxide modulation for translational studies.
Intravascular stents increase long-term patency but their effects on the vascular mechanics of adjacent segments have not been studied. In this study, stents were deployed in the rabbit abdominal aorta after 1 week of normal diet, 1% cholesterol diet or 1% cholesterol diet with L-nitro arginine (L-NA 60 mg/l water). Intravascular ultrasound showed a small distal decrease in vessel distensibility (area/pressure * 100) before stenting. Distensibility was almost abolished by stenting (0.12 +/- 0.01, p < 0.001), but was increased proximal to the stent and decreased distal to the stent both acutely (proximal: 1.18 +/- 0.10 vs distal: 0.65 +/- 0.06, p < 0.001), and at 4 weeks (proximal: 1.05 +/- 0.08 vs distal: 0.37 +/- 0.07, p < 0.001). Nitric oxide (NO) activity was enhanced proximal to and within the stent, and remained constant distal to the stent, (versus control, proximal: 57 +/- 23%, stent: 136 +/- 35%, distal: 2 +/- 12%, p < 0.01). The I/M ratio was significantly higher proximal to and within the stent than in the distal segment (proximal: 0.40 +/- 0.10, stent: 0.37 +/- 0.12, distal: 0.12 +/- 0.11, p < 0.01). NO blockade with L-NA prevented hyperdistensibility proximally, and significantly increased the I/M ratio within the stent and distally (stent: 0.81 +/- 0.19, distal: 0.30 +/- 0.10, p < 0.05) but not proximally (0.38 +/- 0.09). In conclusion, aortic stenting increases proximal vascular distensibility and intimal lesion formation. Nitric oxide blockade augments intimal growth within but not proximal to the stent.
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Schwarzacher et al. (2001) studied Vascular mechanics and neointima formation. Aortic stenting and L-nitro arginine (L-NA) vs. Control (no L-NA) was evaluated on Vascular distensibility and intimal lesion formation (I/M ratio). Aortic stenting increases proximal vascular distensibility and intimal lesion formation, while nitric oxide blockade augments intimal growth within but not proximal to the stent.
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