Stenting of Peripheral Vessels
Vessel access is achieved with an 18-gauge needle or a micropuncture kit that utilizes a smaller-caliber needle and wire. Use of a micropuncture kit under ultrasonographic guidance is recommended for brachial arterial access.
A wire of appropriate diameter and length is used to cross the lesion of concern. It must be long enough to accommodate the shaft length of the stent device (which is usually 80 or 135 cm). The access sheath must also be of a diameter sufficient to accommodate the balloon or stent device. Generally, a 5-French sheath is adequate for most balloons less than 8 mm in diameter, but a 6-French sheath is generally the minimum for stents 5 mm or more in diameter. It is critical that the wire always be under direct control outside the body when catheters are exchanged or balloons or stents are advanced.
If angioplasty is to be attempted first, then an appropriately sized balloon (diameter and length vary) is placed across the lesion and inflated to the desired diameter and pressure for 1-2 minutes, with care taken not to exceed the vessel diameter. If a residual stenosis greater than 30-40% or a flow-limiting intimal dissection exists, then placement of a stent is recommended.
Balloon-expandable stents should be matched to the vessel diameter, whereas self-expanding stents may be upsized about 10-15% to maintain enough radial force to appose the vessel wall. After deployment of a self-expanding stent, a balloon may be reinserted and inflated to help with vessel wall apposition. Again, the balloon should not be oversized.
Angioplasty has generally been recommended as first-line therapy for femoral-popliteal disease and tibial disease. However, primary stenting for femoral-popliteal disease is also acceptable. [13] Especially in the case of occlusions, predilatation with a smaller-diameter balloon may be required to pass the stent device across the lesion. Primary stenting without initial angioplasty (with a balloon-expandable stent) is preferred for iliac, renal, subclavian, and mesenteric lesions.
Predilation can facilitate passage of the stent device, especially because balloon-expandable stents are more rigid and less trackable than self-expanding stents. The stent length should be chosen to cover the entire extent of the area harboring disease of concern. If multiple stents are required for sufficient coverage, there should be 1-2 cm of overlap between adjacent stents, and stent placement should generally begin most distally and then proceed proximally.
Finally, angiography should be performed to assess the final result. Distal imaging is recommended to rule out embolization following the intervention.
Complications
Potential complications of peripheral vascular stent insertion include the following:
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Bleeding (hematoma or pseudoaneurysm)
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Infection
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Contrast nephropathy
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Dissection
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Distal embolization
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Stent fracture
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In-stent restenosis or thrombosis - Cilostazol may lower the rate of this complication [14] ; flow-modification stents have also been suggested as a possible means of minimizing this problem [15] ; mechanical [16, 17] and laser-based [18] approaches to atherothrombectomy have been used to treat this condition as well
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Arterial rupture
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Arterial spasm
