Stent balloon-expandable

Stenting of an acutely occluded intracranial vessel may provide fast recanalization by entrapping the thrombus between the stent and the vessel wall. A recent study in which 19 patients with acute occlusions at the ICA terminus n = 8), M1/M2 (n = 7), or basilar artery (n = 4) were treated with balloon-expandable stents showed a TIMI 2 and 3 recanalization rate of 79% and no symptomatic intracranial hemorrhages (Fig. 4.5). ... 

FIGURE 4.5 A 72-year-old man with medical history remarkable for hypertension and dyslipidemia presented with posterior circulation infarct (a). CTA and posterior circulation angiography (left vertebral artery injection) performed demonstrated severe mid-basilar artery stenosis (b and c). Left vertebral artery injection demonstrated near-complete reversal of the stenosis after a drug-eluting balloon expandable stent (Cypher, Cordis Johnson Johnson) was deployed (d). 

Serruys PW, de Jaegere P, Kiemeneij F, et al., for the BENESTENT study group. A comparison of balloon-expandable stent implantation with balloon angioplasty in patients with coronary artery disease. N Engl J Med 1994 331 489 95. 

Lin PH, Chronos NA, Marijianowski MM, et al. Carotid stenting using heparin-coated balloon-expandable stent reduces intimal hyperplasia in a baboon model. J Surg Res 2003 I 12( I ) 84-90. 

Serruys PW, Degertekin M, Tanabe K, etal. Intravascular ultrasound findings in the multicenter, randomized, double-blind RAVEL (RAndomized study with the sirolimus-eluting VEIocrty balloon-expandable stent in the treatment of patients with de novo native coronary artery Lesions) trial. Circulation 2002 ... 

The pivotal Sirolimus-coated BX VELOCITY Balloon-Expandable Stent in Treatment of Patients with De Novo Coronary Artery Lesions (SIRIUS) study of the CYPHER SES demonstrated a low rate of reintervention compared with... 

Moussa I, Leon MB, Bairn DS, et al. Impact of sirolimus-eluting stents on outcome in diabetic patients a SIRIUS (SIRollmUS-coated Bx Velocity balloon-expandable stent in the treatment of patients with de novo coronary artery lesions) substudy. Circulation 2004 109 2273-2278. 

Platelet bound Factor Xa is similarly resistant to inactivation by heparin-AT complex, serving as a source of further thrombin generation. Therefore, drugs such as heparin cannot fully attenuate the thrombotic process, a potentially important concern at the site of arterial injury or foreign body placement in the form of a self-expanding or balloon expandable stent. 

FIGURE 7.10 Schematic of aortic valve implantation sequence delivery catheter deploying a balloon-expandable stent. (From Ref. 62, with permission.)... 

Self-expanding and balloon-expandable stents Resheathable (closed-cell) stents. Solitaire, Trevo, Re Vase Pharmacological vasopressors (e.g., phenylephrine) Mechanical NeuroFlo... 

The high elastic modulus of the metal alloy allowed the creation of the self-expandable WaUstent (Boston Scientific Corp., Natick, MA), while one of the first balloon-expandable stents made of Co-Cr alloy was the Multi-Link Vision coronary stent (Abbott Laboratories, Abbott Park, IL) made of L605 allot (Co-20Cr-15W-10Ni) that provided both strength and increased X-ray attenuation compared to stainless steel, thus allowing for thinner struts [11]. 

Stents can be divided into two main groups on the basis of the method of expansion. Balloon-expandable stents either arrive premounted on a balloon angioplasty catheter or are mounted by the doctor prior to the procedure. A balloon catheter with inflation apparatus is shown in Fig. 20.3. While mounted, the stent is moved into place and the balloon inflated to expand the stent to the desired diameter. Figure 20.4 illustrates the placement and inflation procedure for balloon-expandable stents. In contrast, self-expanding stents come premounted or sheathed. Once deployed to the treatment area, the sheath is pulled back, allowing the stent to expand to its predetermined diameter. Balloon-expandable stents can be further subdivided into slotted-tube and coil-based designs (Oes-terle et al., 1998). 

The Seta device from Latecba departs from traditional devices, in that it uses a balloon-expandable stent and a knitted polyester graft. It is felt that the balloon-expandable stent may decrease the risk of aortic neck dilatation and mold more favorably to the aorta. Also, there is a suggestion that the knitted graft material may encourage better tissue incorporation. 

Bu Lock FA, Tometzki AJ, Kitchiner DJ, Arnold R, Peart I, Walsh KP. Balloon expandable stents for systemic venous pathway stenosis late after Mustard s operation. Heart 1998 79 225-9. 

Balloon-expandable stents for example, Palmaz (Johnson 8c Johnson, Warren, NJ) and Tantalum Strecker (Boston Scientific). These stents are inserted mounted on an angioplasty balloon catheter and expanded by the balloon when in an optimum position across the stricture. Balloon-expandable stents are difficult to deploy around curves and have reduced radial force compared... 

Balloon-expandable stents do not have an inherent dynamic radial expansile force, but can resist external compressive forces. Due to their design, they can be expanded from a small introductory... 

The second balloon-expandable stent type has been made from a single tantalum filament, which was woven into a cylindrical wire mesh. Again, the choice of thickness of the tantalum wire and the knitting technique determines the mechanical properties of this stent type. This particular stent type has been known as the Strecker stent (Boston Scientific, Natick, MA) (Strecker et al. 1990). This stent requires balloon dilatation for deployment like the Palmaz type stents. Generally, it is more flexible but also less resistant to compressive forces than the stainless steel balloon-expandable stents. Stents for use in the respiratory system came in lengths between 20 and 40 mm, and were expandable to diameters between 5 and 11 mm. Due to its relatively low radial forces, this particular stent had the unique feature of possible stent removal, thus it can be used for temporary stenting (Schmidt et al. 1999 Witt et al. 1997). 

There are no dedicated tracheobronchial covered balloon-expandable stents available yet. The Gianturco stent for tracheobronchial application is commercially only provided as an uncovered stent. 

The Palmaz stent as a balloon expandable stent has a specific complication profile. Once the stent is compressed due to extrinsic forces, e.g., an enlarging tumor mass, adjacent vascular structures, or a vigorous cough, it has no abihty to reexpand. Compression of a Palmaz stent has been noted in a patient with a thoracic aortic aneurysm (Slonim et al. 1998), in a patient after severe coughing (Hautmann and Huber 1996), and in two patients with external malignant tumors (Beer et al. 1999). 

Richter GM, Roeren TK, Noeldge G, Landwehr P, Lackner KG, Kauffmann GW. Balloon-expandable stent placement vs PTA in the [liac artery stenoses and occlusions long-term results of a randomized trial (abstract). J Vase Interventional Radiol 1992 3 9. 

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