Stent secondary

The AHA/ASA guidelines recommend that antiplatelet therapy as the cornerstone of antithrombotic therapy for the secondary prevention of ischemic stroke and should be used in noncardioembolic strokes. Aspirin, dopidogrel, and extended-release dipyridamole plus aspirin are all considered first-line antiplatelet agents (see Table 13-1). The combination of aspirin and clopido-grel can only be recommended in patients with ischemic stroke and a recent history of myocardial infarction or coronary stent placement and then only with ultra-low-dose aspirin to minimize bleeding risk. 

In an optical micrograph of a commercially available nitinol stent s surface examined prior to implantation, surface craters can readily be discerned. These large surface defects are on the order of 1 to 10 p.m and are probably formed secondary to surface heating during laser cutting. As mentioned above, these defects link the macro and micro scales because crevices promote electrochemical corrosion as well as mechanical instability, each of which is linked to the other. Once implanted, as the nitinol is stressed and bent, the region around the pits experiences tremendous, disproportionate strain. It is here that the titanium oxide layer can fracture and expose the underlying surface to corrosion (9). 

Virmani R, Guagliumi G, Farb A, et al. Localized Hypersensitivity and late coronary thrombosis secondary to a sirolimus-eluting stent. Should we be cautious Circulation 2004 109 701-705. 

PTCA). The primary objective was to evaluate the occurrence of major adverse cardiac events (MACE) [death, recurrent myocardial infarction (Ml), or clinically driven target lesion revascularization] 30 days postprocedure. The secondary objectives were to evaluate the binary restenosis, incidence of (sub)acute stent thrombosis at 30 days follow-up, MACE at 6 and 12 months and the QCA endpoints at 6 months. This study was designed to allow a comparison with the patient population and the results of a larger randomized DISTINCT (BiodivYsio stent in controlled clinical trial) study previously conducted in the U.S. 

Secondary endpoints Binary restenosis at 4 months follow-up (defined as > 50% diameter stenosis by QCA) Quantitative coronary angiography endpoints including late loss, loss index, late absolute MLD at 4 months Incidence of (sub)acute stent thrombosis (SAT) to 30 day follow-up, MACE at 4 and 9 months... 

Ticlopidine is a thienopyridine derivative with potent antiplatelet activity associated with inhibition of ADP-induced platelet aggregation. It was first used in Europe in 1978 in the secondary prevention of stroke and coronary events, the treatment of peripheral vascular disease, and after vascular stent placement. However, the use of ticlopidine has been progressively restricted in some countries because of its serious adverse effects. It has largely been superseded by clopidogrel. 

In secondary prevention, carotid endarterectomy of an ulcerated and/or stenotic carotid artery is a very effective way to reduce stroke incidence and recurrence in appropriate patients and in centers where the operative morbidity and mortality are low. In fact, in ischemic stroke patients with 70% to 99% stenosis of an ipsilateral internal carotid artery, recurrent stroke risk can be reduced by up to 48% compared with medical therapy alone when combined with aspirin 325 mg daily. In patients in whom the risk of endarterectomy is thought to be excessive, carotid stenting may be effective in reducing recurrent stroke risk but is less invasive. Carotid stenting is still considered investigational, however, and issues remain regarding the optimal methods and patients for this procedure. 

Secondary prevention. In a meta-analysis of randomised, controlled studies in patients following myocardial infarction or acute coronary syndrome, intensive warfarin (INR greater than 2) plus aspirin 80 to 325 mg daily was associated with 2.5-fold increased risk of major bleeding, when compared with aspirin alone, although the actual incidence was low (1.5% versus 0.6%). This analysis excluded studies of coronary stenting, see (b) above. In another similar meta-analysis, combined use of aspirin and warfarin (INR 2 to 3) was associated with a 2.3 odds ratio of a major bleed, when compared with aspirin alone.The number needed to treat to cause one major bleed was 100. This compared with a number needed to treat to avoid one major adverse event (death, myocardial infarction or stroke) of 33. 

Isolated cases of laparoscopic ovarian vein ligation have been reported [32] however, there are no large series published to date. Non-embolic interventional treatments such as venous stenting and surgical bypass have been reported in small numbers of patients when the varicosities are secondary to venous obstruction [33]. 

In five recent series comprising 6-12 patients each (De Baere et aL 1997 Pinto 1997 Soetikno et al. 1998 Binkert et aL 1996 Feretis et al. 1996) various types of Wallstents were used (16-mm vascular rolling membrane, 20 to 22-mm oesophageal, 20 to 22 mm enteral Wallstents). Initial palliative success was achieved in 80%-100% (m=92%) of the total of 43 reported patients with a technical success rate of 83%-100% (m=95%). In all but four patients the stents were inserted via peroral route. Long-term follow-up was limited since most patients died within 6 months. Reobstruction rates varied from 8%-50% (m=25%) but secondary durable palliation until death or at the end of the study was achieved in 80%-100% (m=86%). 

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