Willfort-Ehringer Andrea, Ahmadi Ramazanali, Gruber Diego, Gschwandtner Michael E, Haumer Angelika, Haumer Markus, Ehringer Herbert
Department of Medical Angiology, General Hospital of Vienna, University of Vienna Medical School, Austria.
J Vasc Surg. 2004 Apr;39(4):728-34. doi: 10.1016/j.jvs.2003.12.029.
This study was undertaken to study negative and positive arterial remodeling processes within self-expanding carotid stents, their interaction, and the resulting changes in hemodynamics over 2 years, with duplex ultrasound scanning.
One hundred twelve consecutive patients with 121 successfully stented carotid arteries were examined with color-coded duplex ultrasound scanning the day after the stent procedure and at 3, 6, 12, and 24 months of follow-up. The stent diameters at the proximal, middle, and distal regions, and the maximal neointimal thickness (B-mode) and hemodynamic parameters were recorded. Pre-interventional plaques were assigned to three types: soft, fibrous, and largely calcified.
The diameters of the self-expanding stents steadily increased over 2 years (positive arterial remodeling), from (mean +/- SD) 5.80 +/- 0.89 mm to 6.77 +/- 0.98 mm in the proximal stent area, from 3.51 +/- 0.76 mm to 4.92 +/- 0.89 mm in the middle stent area, and from 3.7 +/- 0.5 mm to 4.68 +/- 0.61 mm in the distal stent area (P<.001). Stent expansion was most marked in the middle stent area, depending on the type of pre-interventional plaque. The extent in stent expansion was more in soft than in fibrous and calcified plaques (P<.001). Neointimal thickness increased up to 12 months, and stabilized thereafter. The mean (+/- SD) neointimal thickness at 3, 6, 12, and 24 months was 0.61 +/- 0.28 mm, 0.97 +/- 0.39 mm, 1.06 +/- 0.36 mm, and 1.12 +/- 0.38 mm, respectively. These complex interactions resulted in the dominance of negative remodeling secondary to neointimal proliferation, with an increased flow ratio during the first year, from 1.16 +/- 0.37 at day 1 to 1.23 +/- 0.46 at 3 months, 1.67 +/- 1.37 at 6 months, and 1.57 +/- 0.70 at 12 months (P<.001), followed by a tendency to decrease as a result of stent expansion thereafter (flow ratio at 24 months, 1.49 +/- 0.70). Two of 121 stents (1.6%) had recurrent stenosis that required a secondary procedure.
Neointimal proliferation or negative arterial remodeling prevails up to 12 months, and may give rise to rare stent recurrent stenosis. Stent expansion reduces this effect in the first year, and dominates in the second year. This might contribute to the good mid-term outcome of carotid stenting. Poor stent expansion in heavily calcified plaques calls for primary surgical management.
本研究旨在通过双功超声扫描，研究自膨式颈动脉支架内的正负动脉重塑过程、它们之间的相互作用以及由此导致的两年内血流动力学变化。
连续121例成功置入支架的112例患者，在支架置入术后第1天以及随访3、6、12和24个月时，采用彩色编码双功超声扫描进行检查。记录支架近端、中部和远端区域的直径，以及最大新生内膜厚度（B型）和血流动力学参数。干预前的斑块分为三种类型：软斑、纤维斑和大部分钙化斑。
自膨式支架的直径在2年内稳步增加（正向动脉重塑），近端支架区域从（平均±标准差）5.80±0.89mm增加到6.77±0.98mm，中部支架区域从3.51±0.76mm增加到4.92±0.89mm，远端支架区域从3.7±0.5mm增加到4.68±0.61mm（P<0.001）。支架扩张在中部支架区域最为明显，取决于干预前斑块的类型。软斑中的支架扩张程度大于纤维斑和钙化斑（P<0.001）。新生内膜厚度在12个月内增加，此后稳定。3、6、12和24个月时的平均（±标准差）新生内膜厚度分别为0.61±0.28mm、0.97±0.39mm、1.06±0.36mm和1.12±0.38mm。这些复杂的相互作用导致新生内膜增殖继发的负向重塑占主导，第一年的血流比增加，从第1天的1.16±0.37增加到3个月时的1.23±0.46、6个月时的1.67±1.37和12个月时的1.57±0.70（P<0.001），此后由于支架扩张而有下降趋势（24个月时的血流比为1.49±0.70）。121个支架中有2个（1.6%）发生复发性狭窄，需要二次手术。
新生内膜增殖或负向动脉重塑在12个月内占主导，可能导致罕见的支架复发性狭窄。支架扩张在第一年减少了这种影响，并在第二年占主导。这可能有助于颈动脉支架置入术的良好中期结果。重度钙化斑块中支架扩张不良需要进行一期手术治疗。
