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Carotid artery stenting, compared with carotid endarterectomy, is emerging as an effective and less invasive method of revascularization for extracranial carotid artery stenosis. Carotid stenting is established as the treatment of choice for certain high-risk patient subsets, and ongoing clinical trials are evaluating this method across a broader clinical spectrum, including asymptomatic patients. For carotid stenting to reach its full potential, an acceptable risk of periprocedural complications, particularly in low-risk patients, must be ensured (the "3% rule"). The present article provides an in-depth review of carotid stenting, with special emphasis on the process of risk stratification pertaining to clinical, anatomic, and procedural considerations necessary to optimize procedural safety and patient outcomes.

Objectives: We report intravascular ultrasound (IVUS) findings after crush-stenting of bifurcation lesions., Background: Preliminary results with the crush-stent technique are encouraging; however, isolated reports suggest that restenosis at the side branch (SB) ostium continues to be a problem., Methods: Forty patients with bifurcation lesions underwent crush-stenting with the sirolimus-eluting stent. Postintervention IVUS was performed in both branches in 25 lesions and only the main vessel (MV) in 15 lesions; IVUS analysis included five distinct locations: MV proximal stent, crush area, distal stent, SB ostium, and SB distal stent., Results: Overall, the MV minimum stent area was larger than the SB (6.7 +/- 1.7 mm2 vs. 4.4 +/- 1.4 mm2, p < 0.0001, respectively). When only the MV was considered, the minimum stent area was found in the crush area (rather than the proximal or MV distal stent) in 56%. When both the MV and the SB were considered, the minimum stent area was found at the SB ostium in 68%. The MV minimum stent area measured <4 mm2 in 8% of lesions and <5 mm2 in 20%. For the SB, a minimum stent area <4 mm2 was found in 44%, and a minimum stent area <5 mm2 in 76%, typically at the ostium. "Incomplete crushing"--incomplete apposition of SB or MV stent struts against the MV wall proximal to the carina--was seen in >60% of non-left main lesions., Conclusions: In the majority of bifurcation lesions treated with the crush technique, the smallest minimum stent area appeared at the SB ostium. This may contribute to a higher restenosis rate at this location.

Obstructive atherosclerotic carotid bifurcation disease is responsible for approximately 30% of stroke cases in the United States. Any successful treatment of this disease should demonstrate significant and durable reduction in the related risk for stroke without compromising the patient safety. The indications for CAS are evolving as the techniques, the stents and catheter technology advance. There is an ongoing need to improve the equipment suitable for carotid stenting and a need to enhance the safety of the procedure. Often, when a technical problem is encountered, it is attributed to the inadequacy of the devices currently available. As the technology improves, particularly with the application of the anti-embolization devices, the indications and contraindication may need to be revised.

An advanced six-ring morpholino backbone c-myc antisense (AVI-4126) was shown to inhibit c-myc expression and intimal hyperplasia after local catheter delivery in a porcine balloon injury model. The purpose of this study was to investigate the effects of an AVI-4126-eluting phosphorylcholine-coated (PC) stent on c-myc expression restenosis and vascular healing after stent implantation in porcine coronary arteries. PC stents were loaded with AVI-4126 using soak trap. Nine pigs underwent AVI-4126 PC coronary stent implantation (two stents/animal). Two to six hours postprocedure, three pigs were sacrificed and stented segments were analyzed by Western blot for c-myc expression. In chronic experiments, six pigs (12 stent sites) were sacrificed at 28 days following intervention and vessels were perfusion-fixed. High-performance liquid chromatography analysis of plasma samples showed minimal presence of the antisense. Western blot analysis of the stented vessels demonstrated inhibition of c-myc expression at 2 and 6 hr after procedure. Quantitative histologic morphometry showed that the neointimal area was significantly reduced (by 40%) in the antisense-coated group compared with control (2.3 +/- 0.7 vs. 3.9 +/- 0.8 mm(2), respectively; P = 0.0077). Immunostaining and electron microscopy demonstrated complete endothelialization, without fibrin deposition, thrombosis, or necrosis in all implanted stents. In the porcine coronary model, an advanced c-myc-eluting PC stent blocked c-myc expression and significantly inhibited myointimal hyperplasia and allowed complete reendothelialization and healing response., (Copyright 2004 Wiley-Liss, Inc.)

Background: The distal-balloon protection system is being evaluated for its efficacy in preventing embolic neurological events during carotid stenting (CAS). We sought to determine the effect of this system on the frequency of the Doppler-detected microembolic signals (MES) during CAS., Methods: Using transcranial Doppler, we compared the frequency of MES during CAS in 2 groups; 39 patients without distal protection and 37 with the distal-balloon protection system (GuardWire, Percusurge, Sunnyville, CA). There was no significant difference in the clinical or angiographic characteristics between the 2 groups. Three phases with increased MES counts were identified during the unprotected CAS; stent deployment, predilation, and postdilation (mean+/-SD: 75+/-57, 32+/-36, and 27+/-25, respectively)., Results: The distal-balloon protection significantly reduced the frequency of MES during CAS (MES-counts: 164+/-108 in the control vs 68+/-83 in the protection group, p=0.002) particularly during these 3 phases. MES in the protection group were detected predominantly during sheath placement, guidewire manipulation and during the distal-balloon deflation., Conclusions: Three phases with increased MES counts were identified during the unprotected CAS, e.g. stent deployment, predilation and postdilation. The distal-balloon protection system significantly reduced the frequency of MES during CAS, particularly during these 3 phases.

Objectives: We evaluated the long-term influence of intramural delivery of advanced c-myc neutrally charged antisense oligonucleotides (Resten-NG) on neointimal hyperplasia after stenting in a pig model., Background: Neointimal hyperplasia after percutaneous coronary interventions is one of the key components of the restenotic process. The c-myc is a critical cell division cycle protein involved in the formation of neointima., Methods: In short-term experiments, different doses (from 500 microg to 5 mg) of Resten-NG or saline were delivered to the stent implantation site with an infiltrator delivery system (Interventional Technologies, San Diego, California). Animals were euthanized at 2, 6 and 18 h after interventions, and excised vessels were analyzed for c-myc expression by Western blot. In long-term experiments, either saline or a dose of 1, 5 or 10 mg of Resten-NG was delivered in the same fashion, and animals were euthanized at 28 days after the intervention., Results: Western blot analysis demonstrated inhibition of c-myc expression and was dose dependent. Morphometry showed that the intimal area was 3.88 +/- 1.04 mm(2) in the control. There was statistically significant reduction of intimal areas in the 5 and 10 mg groups (2.01 +/- 0.66 and 1.95 +/- 0.91, respectively, p < 0.001) but no significant reduction in the 1 mg group (2.81 +/- 0.56, p > 0.5) in comparison with control., Conclusions: This study demonstrated that intramural delivery of advanced c-myc neutrally charged antisense morpholino compound completely inhibits c-myc expression and dramatically reduces neointimal formation in a dose dependent fashion in a porcine coronary stent restenosis model, while allowing for complete vascular healing.

A 61-year-old man underwent carotid stenting with the distal-balloon protection system for symptomatic carotid artery stenosis. During the procedure, progressive elevation of the systolic blood pressure occurred, reaching a peak of 220 mm Hg immediately following deflation of the distal balloon. This was associated with severe headaches and progressive deterioration in the mental status to a coma. Head CT scan showed massive subarachnoidal hemorrhage contralateral to the stented side and a secondary intracerebral hemorrhage. Despite immediate successful blood pressure control, his condition deteriorated and he died 2 days later., (Copyright 2001 Wiley-Liss, Inc.)

Purpose: To document the feasibility of brachial artery access for carotid stenting with distal-balloon protection of the internal carotid artery (ICA)., Technique: Via percutaneous access to the brachial artery, a large double-curve catheter is advanced into the aortic arch over a hydrophilic guidewire to cannulate the left common carotid artery. Following sheath exchange, a GuardWire distal-protection balloon is positioned within the left ICA distal to the stenosis. The lesion is dilated, followed by deployment and dilation of a self-expanding stent. Transcranial Doppler monitoring shows only scarce microembolic signals during the procedure., Conclusions: Carotid stenting with distal balloon protection via the brachial artery appears feasible as an alternative to standard femoral access.

Background: The distal-balloon protection system is being evaluated for its efficacy in preventing embolic neurological events during carotid stenting (CAS). We sought to determine the effect of this system on the frequency of Doppler-detected microembolic signals (MES) during CAS., Methods and Results: Using transcranial Doppler, we compared the frequency of MES during CAS in 2 groups: 39 patients without distal protection and 37 who used the distal-balloon protection system (GuardWire). There were no significant differences in the clinical or angiographic characteristics between the 2 groups. Three phases with increased MES counts were identified during unprotected CAS; these were stent deployment, predilation, and postdilation (75+/-57, 32+/-36, and 27+/-25 METS, respectively). The distal-balloon protection significantly reduced the frequency of MES during CAS (MES counts: 164+/-108 in the control versus 68+/-83 in the protection group; P=0.002), particularly during these 3 phases. MES in the protection group were detected predominantly during sheath placement, guidewire manipulation, and distal-balloon deflation., Conclusion: Three phases with increased MES counts were identified during unprotected CAS (eg, stent deployment, predilation, and postdilation). The distal-balloon protection system significantly reduced the frequency of MES during CAS, particularly during these 3 phases.

Background and Purpose: Ambulatory procedures increase patient comfort and enhance cost-effectiveness. We sought to determine the feasibility and safety of ambulatory carotid stenting., Methods: A selected group of patients was admitted and discharged the same day after the carotid stenting procedure. Immediate and short-term outcomes are reported., Results: A total of 98 ambulatory carotid stenting procedures (98 hemispheres in 92 patients) were performed. There were 66 men (72%), and the mean age was 70+/-9 years. Of the patients, 28% had neurological symptoms related to the treated artery within 3 months before the procedure. Sixteen percent of the patients had prior carotid endarterectomy, 4% had prior ipsilateral neck radiation, and 8% had complete occlusion of the contralateral internal carotid artery. Successful access site hemostasis was ensured in all patients with suture-mediated vascular closure devices in 96 (98%) and manual compression in 2. Clinical follow-up was available for 96% of the patients at a mean time of 6+/-4 months. There were no neurological events, deaths, repeated procedures, or major access site complications., Conclusions: Ambulatory carotid stenting is both safe and feasible. This approach will enhance the applicability of the procedure by increasing patient comfort and potentially reducing procedural costs.

Purpose: To describe a potential route for embolization to the middle cerebral artery (MCA) during carotid stenting with the distal balloon protection system., Case Report: An 82-year-old man with symptomatic severe carotid artery stenosis underwent elective carotid stenting with distal-balloon protection. Despite complete occlusion of the distal internal carotid artery, frequent emboli were detected in the ipsilateral MCA by transcranial Doppler (TCD) during the procedure. Intracranial angiography, performed during the distal-balloon protection, revealed filling of the MCA through collaterals from the ipsilateral external carotid artery. The procedure was successfully completed without complications. The patient remains asymptomatic at 6 months., Conclusions: During carotid stenting with distal-balloon protection, asymptomatic embolization into the ipsilateral MCA may occur through collateral circulation. The clinical significance of these emboli is uncertain.

Recurrent stenosis post-carotid endarterectomy (CEA) is not a solitary or unusual phenomenon. Compared to the initial CEA, the reoperation is often more technically challenging and frequently results in local and neurological complications. Carotid artery angioplasty with stenting (CAS) is currently being investigated as an alternative to carotid endarterectomy. In our study, ninety-nine patients underwent CAS in 110 arteries. Procedural success was 99% (109/110). Our results show that CAS treatment in post-CEA restenosis, especially with improved technique and distal protection, is safe with a low neurological complication rate, without any "local" complications and without any cranial nerve palsies. This study suggests that the future primary mode of treatment of post-CEA restenosis might be carotid stenting rather than surgery.

Background: Carotid stenting is a less invasive percutaneous procedure than carotid endarterectomy for the treatment of carotid stenosis. Reports suggest that it can be performed with periprocedural complication rates similar to those of carotid endarterectomy. The purpose of this study was to determine short- and long-term outcomes in the largest prospective cohort of carotid stenting patients., Methods and Results: This study followed 528 consecutive patients (604 hemispheres/arteries) undergoing carotid stenting. There was a 0.6% (n=3) fatal stroke rate and 1% (n=5) nonstroke death rate at 30 days. The major stroke rate was 1% (n=6), and the minor stroke rate was 4.8% (n=29). The overall 30-day stroke and death rate was 7.4% (n=43). Over the 5-year study period, the 30-day minor stroke rate improved from 7.1% (n=7) for the first year to 3.1% (n=5) for the fifth year (P:<0.05 for trend). The best predictor of 30-day stroke and death was age >/=80 years. After the 30-day period, the incidence of fatal and nonfatal stroke was 3.2% (n=31). On Kaplan-Meier analysis, the 3-year freedom from ipsilateral or fatal stroke was 92+/-1%., Conclusions: Experience from a single group of operators demonstrates that carotid stenting can be performed with an acceptable 30-day complication rate. Late follow-up also demonstrates a low rate of fatal and nonfatal stroke. These results suggest that carotid stenting may be comparable to carotid endarterectomy, and it underscores the clinical equipoise and premise for the National Institute of Health-supported, randomized Carotid Revascularization Endarterectomy Versus Stent Trial comparing carotid stenting with carotid endarterectomy.

Purpose: To present the results of a multicenter registry established to collect data on carotid stent procedures in patients with restenosis following carotid endarterectomy., Methods: The procedural details, outcomes, and late follow-up results were collected from 14 centers in the United States. Thirty-day and late stroke and death rates were analyzed., Results: Three hundred and thirty-eight patients (201 men; 71 +/- 8 years) underwent carotid stenting in 358 arteries. The average duration from carotid endarterectomy was 5.5 +/- 7.3 years. Sixty-one percent of the patients were asymptomatic. The overall 30-day stroke and death rate was 3.7%. The minor stroke rate was 1.7% (6/358), and the major nonfatal stroke rate was 0.8% (3/358). The fatal stroke rate was 0.3% (1/358), and the nonstroke-related death rate was 0.9% (3/338). There was 1 (0.3%) fatal and 1 (0.3%) nonfatal stroke during the follow-up period. The overall 3-year rate of freedom from all fatal and nonfatal strokes was 96% +/- 1% (+/- SE)., Conclusions: Carotid artery stenting can be performed in patients with restenosis following carotid endarterectomy with 30-day complication rates comparable to those of most published studies on repeat carotid endarterectomy. Results of late follow-up suggest that this technique is durable and efficacious.

Background and Purpose: Carotid endarterectomy (CEA) is one of the most frequently performed operations in the United States. To offer patients a less invasive means to achieve the same goal, carotid artery stenting (CAS) is investigated as an alternative treatment to CEA., Methods: Three hundred ninety patients underwent CAS, with 451 vessels treated. CAS was performed using a coaxial system with a 7F 90-cm sheath for predilation, stent placement, and stent dilation. Pretreatment antiplatelet therapy was administered. We currently practice same-day admissions and 23-hour discharges., Results: The technical success rate was 98%. The 30-day mortality/morbidity rates were as follows: death, 1.7% (two [0.5%] neurologic and five [1.2%] systemic] major strokes, 0.9% (two of four were related to the intervention); minor strokes, 5.5%. Among 25 patients who suffered minor strokes, 14 achieved complete recovery. On an annual basis, the incidence of minor stroke declined from 6.8% (1994-1995), to 5.8% (1995-1996), 5.3% (1996-1997), and then 4% (1997-1998), with no major strokes or neurologic deaths occurring during the 1997 to 1998 period., Conclusion: CAS is an effective treatment for carotid stenosis. With proper selection of patients and meticulous technique, complication rates compare favorably with those of CEA.

The technique of carotid stenting has undergone significant refinement since its introduction and continues to improve as experience with the procedure matures and more suitable equipment becomes available. Improved stent designs and the utilization of cerebral protection devices are expected to significantly impact on the technique, its ultimate outcomes, and widespread application. In using the currently available technology for carotid stenting, patient selection and meticulous attention to procedural details are very important in minimizing embolic events. In this article, we provide a comprehensive practical discussion of the state-of-the-art carotid stenting techniques that have allowed us to maintain low event rates.

Purpose: To present our experience with carotid artery stenting as an alternative treatment to endarterectomy in patients with radiation-induced carotid artery occlusive disease., Methods and Results: Fourteen patients (10 males; mean age 61 years, range 52 to 79) underwent percutaneous stenting of 15 carotid arteries for severe radiation-induced extracranial stenoses. Technical success was achieved in all patients, with reduction of the mean stenosis from 77% +/- 6% to 8% +/- 2%. In 2 patients, ipsilateral vertebral artery lesions were stented concomitantly. One patient had a minor stroke after the procedure but recovered fully in 2 days. No other complications were encountered. Nine (64%) patients had 6-month follow-up imaging (angiography or duplex scanning) that showed no evidence of restenoses (obstruction > or = 50%). At 18 +/- 2 months, 3 (21%) patients had died from unrelated causes. No neurological events occurred, and no repeat carotid artery interventions were required in the remaining patients., Conclusions: Carotid stenting is an effective treatment option for severe radiation-induced carotid artery occlusive disease.

Objective: Although percutaneous angioplasty and stenting (PTAS) of carotid bifurcation lesions is feasible and appropriate for surgically inaccessible lesions, its general role and comparative value remain unclarified. Moreover, the acceptance of carotid PTAS has been limited by its potential for producing embolic debris. This study used an ex vivo model to evaluate the efficacy of a novel filter device to entrap emboli during PTAS of human carotid plaques., Methods: Eight carotid bifurcation plaques were obtained from patients who underwent carotid endarterectomy for high-grade atherosclerotic stenosis (>90%). The mean age of the patients was 63 years, and six patients were symptomatic. Each plaque was encased with polytetrafluoroethylene material to simulate adventitia and was connected to a perfusion circuit, which provided continuous flow through the plaque. The filter device consisted of an expandable polymeric membrane with multiple micro pores that was attached to the distal end of a 0.014-in wire with a shapeable tip. This filter was encased in a delivery catheter. With fluoroscopic guidance, the filter wire was passed through the stenosis and the delivery catheter was then retracted to open the filter to capture particles released into the distal internal carotid artery. PTAS with a self-expandable stent then was carried out over the filter wire. The particles released during the initial filter passage, those captured in the filter, and those that flowed through or around the filter (missed) were collected and analyzed with light microscopy., Results: Filter deployment, PTAS, and filter retrieval were achieved successfully with each lesion. Because the filter has a low crossing profile, it passed through the stenoses smoothly and only produced occasional small particles. PTAS improved the angiographic stenosis from 96.2% +/- 3.7% to 1.3% +/- 1.6%. The mean number and the maximum size of the particles that were released during initial filter passage, missed, and captured by the filter device were 3.1 and 500 microm, 2.8 and 360 microm, 20.1 and 1100 microm, respectively. Most of the particles and those of large size were released during PTAS. The filter captured 88% of these particles., Conclusion: These study results show that this filter device, at least in this model, did not add complexity to the interventional procedure itself. Furthermore, the filter may markedly decrease embolic events during carotid PTAS and expand the indications for this procedure.

Purpose: To report a case of carotid artery stenting for asymptomatic carotid restenosis performed in an outpatient setting., Methods and Results: A 68-year-old man with right carotid restenosis after repeat carotid endarterectomy underwent carotid angioplasty and stenting on an ambulatory basis. The procedure to implant a Smart stent required 45 minutes; the femoral access site was closed with a puncture closure device. The patient experienced no sequelae to this procedure and is well 6 months after treatment., Conclusions: Outpatient delivery of percutaneous carotid stenting may be feasible in appropriately selected patients.

Purpose: To examine the usefulness of a novel method for neurological monitoring during carotid artery stenting (CAS)., Methods: The records of patients who underwent elective CAS between June 1996 and October 1998 were reviewed to identify those who had neurological changes during the procedure. We examined whether the neurological change had been detected by a change in the ability of the patient to respond to predetermined commands involving a small rubber duck placed in the contralateral hand., Results: hundred seventy patients (320 vessels) underwent monitoring using the Duck Squeezing Test; 10 suffered neurological events during the procedure. Four of these were transient and temporally related to balloon inflation. Another 6 were tentatively ascribed to distal embolism. All instances were accompanied by a change in the patient's ability to perform the Duck Squeezing Test, which allowed the identification of the abnormal clinical situation. In addition, there were 4 false-positive tests secondary to the patient accidentally dropping the rubber duck., Conclusions: The Duck Squeezing Test is a sensitive and specific method for monitoring patients during elective CAS. Its practical applicability is based on sound neurophysiological concepts, which underscore the clinical importance of the test.

Object: The authors summarize their experience with stent deployment in the treatment of vertebrobasilar artery (VBA) insufficiency. This is an underdiagnosed condition, and the incidence of significant vertebral artery (VA) stenosis has been underappreciated. Medical therapy has been the mainstay of treatment because of the high rate of morbidity associated with surgical correction of VA stenosis. Recently, some authors have reported acceptable results with the use of percutaneous transluminal angioplasty, but this technique has significant weaknesses such as elastic recoil and problems in achieving safe treatment of dissections., Methods: The authors investigated the feasibility, safety, and outcome of VA stent placement in 50 patients in whom 55 vessels were treated using stents. Technical success was achieved in 54 (98%) of 55 vessels, with no procedure-related complications. However, one patient (2%) died of nonneurological causes, and one (2%) suffered a stroke that occurred within the 30-day postprocedural period and was related to a complicated coronary intervention. Clinical follow-up review performed at a mean of 25 +/- 10 months revealed two patients (4%) with recurrence of VBA symptoms. Six-month angiographic follow up was completed in 90% of eligible patients, with a 10% incidence of restenosis as defined by greater than 50% luminal narrowing., Conclusions: Vertebral artery stent placement is feasible in patients who have significant VA stenosis, with predictably good angiographically demonstrated and clinical results. The 6-month angiographically confirmed restenosis rate appears to be low, as does the clinical recurrence rate. This technique solves the problems of elastic recoil and the treatment of angioplasty-induced dissections. Further prospective comparison with medical preventive strategies is warranted.

Fifty-one patients with severe coexisting carotid and symptomatic coronary artery occlusive disease successfully underwent staged or simultaneous coronary angioplasty and carotid stenting. One pericardial effusion and 2 minor strokes with full recovery occurred in the hospital, but no major neurologic events, myocardial infarction, or death were observed and no repeat revascularization was required within the 30-day follow-up.

Purpose: To examine the impact of age upon the development of neurological and major systemic complications during or after carotid artery stenting., Methods: We reviewed the complications that occurred in patients undergoing elective carotid stent implantation between September 1994 and August 1996. The study population was then divided into 3 groups according to age: > or = 80 (group A), 75 to 79 (group B), and < or = 74 (group C) years. The rates of death, major and minor stroke, and myocardial infarction were compared among the groups, as well as with the rates reported by the major carotid endarterectomy (CEA) trials., Results: During the study period, 182 patients (216 vessels) were treated with carotid stenting. There were 19 (10.4%) complications: 1 (0.5%) death, 2 (1.1%) major strokes, 15 (8.2%) minor strokes, and 1 (0.5%) myocardial infarction. Neurological complications were clearly related to increased age with rates of 25.0% in group A versus 8.6% in group C (p = 0.042). The overall per patient rate of death or major stroke was 1.6% (1.4% per vessel)., Conclusions: Increasing age has a negative impact on the rate of complications in carotid stent patients. However, the majority of those complications are minor. The relative roles of medical therapy, stenting, and CEA in patients > 80 years of age must await the results of randomized trials.

Background: Ticlopidine has been shown to reduce the incidence of stent thrombosis compared with warfarin, but it may cause serious hematological side effects. Clopidogrel, a new thienopyridine derivative, may be a safe alternative to ticlopidine. The aim of this study was to compare the safety and efficacy of clopidogrel and aspirin with those of ticlopidine and aspirin in patients undergoing coronary stent implantation., Methods and Results: The population of this study consisted of 2 groups: patients who underwent coronary stenting and were treated with ticlopidine and aspirin (TA group, n=1406), and patients who underwent coronary stenting followed by treatment with clopidogrel and aspirin (CA group, n=283). At 1-month follow-up, there was no difference in stent thrombosis (1.5% versus 1.4%, P=1.0) or major adverse cardiac events (3.1% versus 2.4%, P=0. 85) between the TA and CA groups, respectively. The probability of any side effect (neutropenia, diarrhea, rash) was significantly higher in the TA group (10.6% versus 5.3%, P=0.006; relative risk, 0. 53; CI, 0.32 to 0.86)., Conclusions: These data suggest that clopidogrel may be an effective pharmacological regimen after coronary stent implantation. Furthermore, the simpler dosing regimen, the absence of neutropenia, and the lower frequency of other side effects make it a safe alternative to ticlopidine.

Coronary stenting in acute coronary syndromes probably increases the risk of acute stent thrombosis. Recently, use of platelet glycoprotein IIb/IIIa receptor antibody has been shown to improve percutaneous transluminal coronary angioplasty (PTCA) outcomes in high risk lesions. The purpose of this analysis was to determine safety and efficacy of platelet glycoprotein IIb/IIIa receptor antibody administration in patients receiving coronary stents in high-risk lesions. Between October 1995 and November 1996, 282 patients with acute ischemic syndromes received coronary stents at our center: 73 had thrombus containing lesions--40 presented with AMI and 33 with unstable angina and make up the study population. The mean age of these patients was 61+/-13 years, 56 were male, 35 had a history of myocardial infarctions (MI), 21 had prior coronary artery bypass graft (CABG), and 21 had prior PTCA. Coronary stenting was used for suboptimal result in 46 patients (63%), threatened closure in 25 patients (34%), and acute closure in 2 patients (3%). Platelet glycoprotein IIb/IIIa receptor antibody was administered during the procedure in 74% and after the procedure in 26%. A total of 115 stents were deployed (Gianturco-Roubin 80, Palmaz-Schatz 29, and Wallstent 6) in 24 LAD, 21 RCA, 15 LCX, and 13 saphenous vein graft (SVG) lesions. Procedural success was 100%. The mean diameter stenosis before and after intervention was 60%+/-31% and 4%+/-14%, respectively. In-hospital events included 1 Q-wave MI (1.4%), 13 non-Q-wave MI (18%), and 1 death (1.4%). There was no subacute stent thrombosis, emergency CABG, or repeat PTCA. Significant in-hospital bleeding complications were noted in seven (10%) patients, with five patients (6.8%) requiring blood transfusions. In this series of patients with acute ischemic syndromes associated with angiographic evidence of thrombus, combined use of platelet glycoprotein IIb/IIIa receptor antibody and stenting resulted in a very low incidence of subacute stent thrombosis and emergency target lesion revascularization. However, bleeding complications were higher than expected with conventional antiplatelet therapy following routine stenting.

Background: Conventional balloon angioplasty of very long de novo coronary lesions or very long coronary dissection caused by angioplasty is associated with low success and high complication rates. Multiple intracoronary stents have been used to treat both conditions, although long-term efficacy has not been defined., Methods and Results: Between June 1993 and December 1995, 47 consecutive patients underwent native coronary angioplasty and stenting with 4 or more stents covering at least 2 consecutive diseased coronary segments. Preangioplasty and poststenting diameter stenoses were 81% +/- 13% and 21% +/- 12%, respectively. Reference vessel diameters were 3.53 +/- 0.55 mm proximal to the stents and 2. 95 +/- 0.62 mm distal to the stents. Average lesion length was 63 +/- 20 mm. The number of stents used was 4.5 +/- 1 per vessel (from 4 to 7). Gianturco Roubin I stents were used in all patients. Coronary Palmaz-Schatz stents were used as supplementary stents in 3 patients. Angiographic success was 100%. In-hospital outcomes include 1 death, 1 coronary bypass surgery, no Q-wave myocardial infarction, and 7 non-Q-wave myocardial infarctions. Long-term follow-up at 430 +/- 199 days was completed in all patients. Thirty-five (76%) patients were asymptomatic, 8 (17%) had class 1 or 2 angina, 1 had a myocardial infarction, 13 (28%) underwent repeat angioplasty, 2 patients had subsequent elective bypass surgery, and 3 died during follow-up., Conclusions: Multiple intracoronary stents for very long lesions or dissection can be performed with acceptable immediate and long-term outcomes.

Abdominal aortic aneurysms (AAAs) are the 13th leading cause of death in the United States. Endovascular stent grafts are currently being investigated in clinical trials as an alternative method for treatment of AAA. Twelve pigs underwent creation of AAA using the abdominus rectus fascia. Postoperatively, all 12 animals underwent angiography, which demonstrated turbulent flow within the created aneurysms. Four of the animals were not stented and served as controls. Eight animals underwent subsequent percutaneous placement of a covered endovascular stent via a right femoral sheath, and the stents were deployed between the renal arteries and the aortic bifurcation. The animals were maintained for 120 days before sacrifice and necropsy. Unstented animals (4) died within 6 days, 3 from rupture. Eight animals underwent endovascular stenting: 5 survived without complications, 3 deaths within 2 days were related to technical complications. The 5 surviving animals were sacrificed at 120 days, and necropsy was conducted with in situ dissections of the aorta and intact stent: 3 experimental animals had correct anatomic positioning of the stent, and 2 had inexact stent placement but survived 120 days with AAA thrombosis. Treatment of AAA in this swine model has been demonstrated via placement of a percutaneous covered stent.

Stenting of the internal carotid artery is facilitated by stenting across the carotid bifurcation and sizing the diameter of a self-expanding stent to the large common carotid segment. This usually results in marked oversizing of the self-expanding stent in the internal carotid segment. This study was done to determine the relationship between stent oversizing and late luminal loss index after stenting of the internal carotid artery. Between September 1995 and March 1997, there were 165 patients (189 vessels) who underwent successful carotid stenting with self-expanding stents. Fifty-nine patients (63 vessels) had six-month follow-up carotid angiograms and on-line quantitative angiographic analysis. The mean reference diameter of the internal carotid arteries was 4.93+/-1.31 mm. Nominal stent size was 5 mm in 4 patients, 6 mm in 6 patients, 8 mm in 106 patients, 10 mm in 77 patients, and 12 mm in 1 patient. The average stent/patient was 1.03+/-0.16. There were three patients who had more than 50% diameter renarrowing at follow-up. The mean late loss index was 0.25+/-0.41. By linear regression analysis, there was no clear linear relationship between stent oversizing and late loss index after stenting (correlation coefficient = -0.21, P = 0.09). When analysis of variance with linear contrast was used to analyze six groups of different stent/artery ratios (from 1.4 to > or = 2), late loss indexes are significantly lower in the groups of high stent/artery ratio than the groups of low stent/artery ratio (P = 0.01). The process of oversizing of self-expanding stents deployed in the internal carotid artery does not appear to be associated with late restenosis and high stent/artery ratio seems to be associated with low late loss index.

We undertook a study to determine the efficacy of stents in reducing restenosis in cardiac allograft vasculopathy. The result shows that coronary stenting significantly reduces restenosis in cardiac allograft vasculopathy compared with balloon angioplasty alone.

Significant carotid stenosis in the presence of an occluded contralateral artery has a poor prognosis with medical therapy alone. Carotid cross clamping during surgical endarterectomy results in critical flow reductions in patients with inadequate collateral flow, and represents a significant risk for procedural strokes. Carotid stenting is being evaluated as an alternative to endarterectomy. We describe the immediate and late outcome of a series of 26 patients treated with carotid stenting in the presence of contralateral carotid occlusion. The mean age of the patients in this group was 65 +/- 9 years, 23 (89%) were men and 10 (39%) were symptomatic from the vessel treated. The procedural success of carotid stenting in this group of patients was 96%. The mean diameter stenosis was reduced from 76 +/- 15% to 2.8 +/- 5%. There was 1 (3.8%) minor stroke in a patient who developed air embolism during baseline angiography. At late follow-up there was no neurologic event in any patient at a mean of 16 +/- 9.5 months after the procedure. Thus, carotid stenting of lesions with contralateral occlusion can be performed successfully with a low incidence of procedural neurologic complications and late stroke.

Background: The evolving technique of carotid stenting is being evaluated as an alternative to endarterectomy. Identification of the factors that predispose a patient to neurological complications would facilitate further refinement of the technique and optimize patient selection., Methods and Results: We analyzed the impact of various clinical, morphological, and procedural determinants on the development of procedural strokes in 231 patients who underwent elective (primary) stenting of 271 extracranial carotid arteries. The mean age of the patients was 68.7+/-10 years, 165 (71%) were males, and 139 (60%) had symptoms attributed to the lesion treated. This series represented a high-risk subset with 164 patients (71%) having significant coronary artery disease, 91 (39%) having bilateral disease, and 28 (12%) having contralateral carotid occlusion. Of the treated vessels, 59 (22%) had prior carotid endarterectomy, 66 (24%) had ulcerated plaques, and 87 (32%) had calcified lesions. Only 37 treated vessels (14%) would have been eligible for inclusion in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). There were 17 (6.2%) minor and 2 (0.7%) major strokes during and within 30 days of the procedure. NASCET-eligible patients had a low (2.7%) risk of procedural strokes after carotid stenting. The results of multivariate analysis revealed advanced age (P=.006) and presence of long or multiple stenoses (P=.006) as independent predictors of procedural strokes., Conclusions: During this procedural developmental phase of carotid stenting, neurological complications were highly dependent on patient selection. Advanced age and long or multiple stenoses were independent predictors of procedural stroke.

Purpose: To determine whether ultrasound (US) is a sensitive follow-up method after placement of a carotid artery stent for the detection of significant stenosis, occlusion, and other complications at early and intermediate follow-up., Materials and Methods: Doppler US examinations were performed after stent placement in 170 carotid arteries in 119 patients with angiographic correlation. Prospective diagnostic US criteria for stenosis were peak-systolic velocity greater than 1.25 m/sec, internal carotid artery (ICA) to common carotid artery (CCA) peak-systolic velocity ratio of greater than or equal to 3:1, and intrastent doubling of peak-systolic velocity. Retrospective criteria for stenosis were also applied: peak-systolic velocity greater than 1.7 m/sec, ICA end-diastolic velocity greater than 0.4 m/sec, ICA/CCA peak-systolic velocity ratio greater than 2.0, and ICA/CCA end-diastolic velocity ratio greater than 2.4., Results: Eighty-seven immediate and 83 intermediate (average, 7.3 months) follow-up US examinations were performed. Two stent occlusions were detected. One or more prospective US criteria were abnormal in 26 arteries with a stent. One or more retrospective criteria were positive in 47 arteries. Angiography showed corresponding findings, with only one significant stenosis (63%) in the ICA stents. Moderate collapse of a CCA stent was depicted at US., Conclusion: Only one significant recurrent stenosis was detected, and no significant stenoses were missed at US. US successfully depicted carotid artery stent occlusion and a moderate stent collapse. Sensitivity in the detection of intrastent stenosis is promising. Further study to refine US criteria in a study with longer term follow-up is needed owing to the lack of significant recurrent stenosis in the intermediate follow-up group.

Unlabelled: Carotid artery stenting is being investigated as a therapeutic strategy for the management of bifurcation stenosis. Palmaz stents were deployed successfully in the carotid arteries of 112 patients using high-pressure balloon inflations. In 11 out of 70 patients who came for 6-mo follow-up angiography, a stent collapse was noted. Carotid ultrasound was able to detect stent collapse in only two patients at follow-up. Only one patient who had collapse of stent along its entire length was symptomatic at follow-up. Repeat balloon angioplasty was performed in 5 patients, 3 of whom had a Wallstents deployed within the Palmaz stent., Conclusion: Stent collapse was observed in a significant number of Palmaz stents within 6 mo of placement in the carotid arteries. These observations should influence the choice of stents for the treatment of extracranial carotid disease.

Angioplasty of aorto-ostial stenosis is associated with lower procedural success and a higher complication rate. The aim of the present study was to compare the acute and long-term results of balloon and new device angioplasty in 110 consecutive patients with right coronary ostial lesions. Patients were divided into 3 groups according to the angioplasty device used: group I (balloon only, n = 26), group II (debulking devices including excimer laser, directional and rotational atherectomy, n = 26), group III (stent, n = 58). Procedural success was highest in group III (96%) followed by group I (88%), and group II (77%). In-hospital complications were similar among the groups (p = NS). Patients in group III achieved the highest acute gain (2.61 mm) followed by groups II (1.92 mm), and I (1.39 mm, p <0.05). During follow up, target lesion revascularization and/or bypass surgery was required in 24% of patients in group III compared with 47% and 40% in groups I and II, respectively (p <0.05). Cardiac-event free survival was highest in the stent group (74%, p <0.005) and was similar between the balloon (39%) and debulking device groups (45%). Thus, among the currently available technologies, stenting of right coronary ostial lesions appears to provide excellent angiographic and long-term results.

Coronary stenting using both Palmaz-Schatz and Gianturco-Roubin stents for branch ostial lesions was performed in 48 patients with high success and low complication rates. The 6-month event-free survival rates were high in these patients.

We describe a patient who underwent stenting of both internal carotid arteries and two coronary arteries. Two combined carotid and coronary procedures were done 4 wk apart to revascularize the patient. The first procedure was complicated by a minor stroke with good recovery. At 6 mo of follow-up, he is asymptomatic and without angiographic restenosis.

Background: Surgical endarterectomy has been shown to be superior to medical management in the management of severe carotid stenosis in both symptomatic and asymptomatic patients. Endarterectomy, although effective, does have limitations, and percutaneous techniques may offer an alternative method of treatment., Methods and Results: The feasibility and safety of percutaneous carotid angioplasty and elective (primary) stenting was evaluated prospectively in a consecutive series of 107 patients. One hundred twenty-six carotid arteries with significant stenosis were treated. This series represented a high-risk subset that included patients with previous ipsilateral endarterectomy and severe medical comorbidity. Forty-five percent of the patients were referred by surgeons. Patients had independent neurological examinations before and after the procedure and follow-up cerebral angiography at 6 months. The mean (+/- SD) stenosis was reduced from 78 +/- 14% to 2 +/- 5%. There were 7 minor strokes, 2 major strokes, and 1 death during the initial hospitalization and first 30 days after the procedure. For the combined end point of all strokes and death, the incidence was 7.9%. For ipsilateral major stroke and death, the incidence was 1.6%. There were no strokes during the follow-up period. Mean angiographic stenosis at 6 months in 81 patients was 18 +/- 16% (range, -21% to 57%). Four (4.9%) of these 81 patients had asymptomatic restenosis. Five asymptomatic patients had repeat intervention: 2 had angioplasty for restenosis, 2 had angioplasty for stent deformation, and 1 had endarterectomy for restenosis., Conclusions: In a high-risk group of patients, percutaneous carotid angioplasty and stenting are feasible and can be performed with low restenosis and repeat intervention rates.

Intravascular ultrasound guidance has been suggested as a prerequisite before managing patients receiving slotted tubular stents without anticoagulation. The purpose of this prospective observational study was to determine if patients receiving this stent can be similarly managed following angiographic guided stent deployment without intravascular ultrasound assistance. A total of 137 patients receiving slotted tubular stents were selected to receive a protocol of aspirin 325 mg and ticlopidine 250 mg for 30 days following the satisfaction of certain angiographic criteria. These criteria were: adequate coverage of intimal dissections, absence of residual filling defects, and normal (TIMI III) flow in the stented vessel at the end of the procedure. The stenting procedure was planned in 68% of patients and unplanned in 32% of patients. During the 30 day clinical follow period there were no stent thrombosis events, no Q-wave myocardial infarctions, and no deaths. Non-Q-wave myocardial infarction occurred in 3 patients (2.2%), hemorrhage requiring blood transfusion in 3 patients (2.2%), and 1 patient (0.7%) developed a pseudo-aneurysm of the cannulated femoral artery. These data indicate that patients receiving slotted tubular stents with optimal angiographic results can be safely managed with the combination of aspirin and ticlopidine without anticoagulation or the need for intravascular ultrasound guidance.

Background and Purpose: Endarterectomy for recurrent carotid stenosis after endarterectomy has a significantly higher complication rate than the original operation. Angioplasty and stenting may offer a useful alternative treatment for these patients., Methods: Between September 1994 and April 1996, 22 patients had 25 carotid arteries treated with angioplasty and stenting for postendarterectomy restenosis. All patients had an independent neurological examination and National Institutes of Health Stroke Scale evaluation before and after the procedure. Patients were treated with aspirin and ticlopidine. All patients were requested to return at 6 months for follow-up angiography. The mean patient age was 69 +/- 7 years, and the mean elapsed time from endarterectomy was 73 +/- 69 months. Seventy-seven percent of the patients were symptomatic., Results: Mean stenosis was reduced from 79 +/- 13% before the procedure to 1.8 +/- 3.6% after stenting. One patient had a minor stroke, for a complication rate of 4% per treated artery. In the eight patients who returned for 6-month angiography, mean stenosis was 19.4 +/- 4.4% and restenosis (> or = 50% stenosis) did not occur., Conclusions: In a small series, angioplasty and stenting appear to be safe and well tolerated for the treatment of postendarterectomy restenosis.

This prospective nonrandomized study was performed comparing aspirin alone (n = 46) versus aspirin and ticlopidine (p = 338) following native coronary artery stenting. There were significantly more stent thrombosis events in the aspirin-only group than in the aspirin and ticlopidine group (6.5% vs 0.9%, p = 0.02) and significantly more Q-wave myocardial infarctions and cardiac-related deaths in the aspirin-only group than in the aspirin and ticlopidine group (6.5% vs 0%, p = 0.002 and 4.4% vs 0.3% p = 0.02, respectively).

Obstructive carotid artery disease is responsible for 60% of strokes in the United States and is the third major cause of death. Stent-supported carotid artery angioplasty has the potential to prevent stroke in thousands of patients and offers a number of potential advantages over surgical revascularization (carotid endarterectomy). Results of the prospective observational study at the University of Alabama at Birmingham indicate that carotid stent-supported angioplasty is safe and probably effective in reducing stroke in patients with high-risk cerebrovascular disease. Technical success was achieved in 99% of 146 procedures; 210 stents were placed in 152 vessels, with only 1 instance of stent thrombosis. The rate of major in-hospital complications was unexpectedly low-only 1 death and 2 major strokes. Seven patients suffered minor strokes, but only 2 were left with minor weakness. When compared with a projected complication rate of 6% had these patients undergone carotid endarterectomy, stenting resulted in fewer major events. At 6-month follow-up, 69 of 74 patients were evaluated by angiography or ultrasound, which detected 8 cases of stent deformation and a restenosis rate of < 5%. Because of these instances of stent deformation, use of the Palmaz (biliary) stent was discontinued. Although 1 patient had a transient ischemic attack, no strokes occurred during follow-up. To date, carotid stenting is an investigational procedure. Cardiovascular interventionalists, industry, and the FDA are encouraged to validate this approach through clinical testing. However, improvements in technique, devices, and adjunctive therapies are needed before the method can be tested in randomized trials.

A case-controlled study was performed comparing hospitalization costs and length of hospital stay in a group of patients managed with antiplatelet therapy only, versus a group treated with anticoagulation using warfarin after coronary artery stenting. The patients managed with antiplatelet therapy alone had significantly reduced total hospitalization costs and a significantly reduced average hospital stay than patients managed with anticoagulation.

Background: The balloon-expandable coil stent has been proved effective in the management of acute and threatened closure after coronary balloon angioplasty and has been shown to reduce restenosis in patients with suboptimal results after coronary balloon angioplasty. Coronary artery stenting has been limited by the occurrence of stent thrombosis and comorbidity related to anticoagulation. This study was undertaken to determine whether anticoagulation may be removed from poststenting protocols, thus reducing comorbidity without increasing stent thrombosis., Methods and Results: Between September 1994 and May 1995, 369 patients received balloon-expandable coil stents in native coronary arteries at our institution. Of these patients, 216 were selected for a protocol of aspirin and ticlopidine (for 1 month) without anticoagulation. Eligibility for this protocol followed satisfaction of certain procedural and angiographic criteria. These criteria included adequate coverage of intimal dissections, absence of residual filling defects, and normal (TIMI grade 3) flow in the stented vessel after high-pressure balloon inflations. Intravascular ultrasound was not used to guide stent deployment. The stenting procedure was planned in 37% of patients and unplanned in 63% of patients, including 25 (12%) for acute or threatened closure. During the 30-day follow-up period, stent thrombosis occurred in 2 patients (0.9%), there was 1 death (0.5%), and 2 patients (0.9%) underwent coronary bypass surgery. Vascular access-site complications occurred in 4 patients (1.9%), and bleeding that required blood transfusion occurred in 4 patients (1.9%)., Conclusions: Patients who receive the coronary balloon-expandable coil stent with optimal angiographic results without intravascular ultrasound guidance can be managed safely with a combination of aspirin and ticlopidine without anticoagulation.

After placement of a Gianturco-Roubin metallic, coiled coronary stent(s) following balloon angioplasty (PTCA), a pre-discharge (7 day) angiogram determined the patency of the old coronary bypass vein graft(s) (SVG) (> or = 5 years remote from their last surgery, mean age: 8.5 +/- 1.8 years). Metallic, coiled stents were successfully deployed in 95/96 (99%) patients within 100/101 (99%) SVGs. The indications for deployment were threatened [81 patients (84%)] or acute [15 patients (16%)] vein graft closure following PTCA. Intragraft urokinase infusion was performed in 17 patients (17%) [6 patients with baseline occlusions; 11 with abrupt closure post PTCA]. Complications encountered included three (3%) in-hospital deaths (two procedure related) two (2%) Q wave myocardial infarctions, six (6%) non-Q wave myocardial infarctions, and 22 (22%) bleeding problems. These included, not mutually exclusively, 21 (22%) requiring transfusions, six (6%) cases of gastrointestinal bleeding, six (6%) pseudoaneurysms, five (5%) retroperitoneal haemorrhages and two (2%) cerebrovascular accidents. All patients received dipyridamole, aspirin, dextran, and anticoagulation (heparin 10-20,000 U intra-procedurally); a heparin infusion was continued for 5 +/- 1 days, despite warfarin administration which attained a therapeutic prothrombin time (PT) (1.5-2 times control) by 3 +/- 1 days. Out of the 95 successfully treated patients, six with eight stented grafts were ineligible for pre-discharge angiography. Of the six, three died in hospital (four SVGs), one had an intracerebral haemorrhage (one SVG), and two were asymptomatic patients with chronic renal failure (three SVGs).(ABSTRACT TRUNCATED AT 250 WORDS)

The balloon expandable, stainless steel, flexible coil stent is a useful device for the management of acute or threatened closure after percutaneous transluminal coronary angioplasty. Appropriate sizing is important to optimize immediate results and reduce the risk of acute thrombosis and restenosis. The in vivo size at deployment of this stent at nominal inflation pressures has not been evaluated. Forty patients who received a single flexible coil stent (10 patients each for stent sizes 4.0, 3.5, 3.0, and 2.5 mm) were studied. The stents were deployed at 3-5 atmospheres. The actual stent size achieved by the stent during deployment was found to be significantly less than the nominal size, being 3.7 +/- 0.3, 3.2 +/- 0.2, and 2.8 +/- 0.2 mm for nominal stent sizes of 4.0, 3.5, and 3.0 mm, respectively (P < 0.005, P < 0.001, and P < 0.01). For a 2.5 mm stent, it was 2.4 +/- 0.2 mm (P = ns). Thus, for optimal results with this device, we recommend that vessels 2.0-2.4 mm in diameter be supported by a 2.5 mm stent, vessels 2.5-2.9 mm in diameter by a 3.0 mm stent, vessels 3.0-3.4 mm in diameter by a 3.5 mm stent, and vessels 3.5-4.0 mm in diameter by a 4.0 mm stent.

Historically, long coronary artery stenoses undergoing percutaneous transluminal coronary angioplasty (PTCA) are reported to have reduced procedural and clinical success in comparison with shorter lesions. The efficacy of long balloons (30 or 40 mm) in long lesions was evaluated. Eighty-two patients had 84 PTCA procedures with a primary long balloon. In all, 86 lesions were available for analysis. Data were collected prospectively on standard PTCA procedure forms. Coronary angiograms were reviewed and measured with digital calipers. Hospital charts were examined for complications. PTCA was performed in the left anterior descending artery in 44 cases (51%), the right coronary artery in 29 (34%) and the circumflex artery in 13 (15%). With the use of a modified classification system, 47 lesions (55%) were class C, 24 (28%) were class B2 and 15 (17%) were class B1. Mean lesion length was 22 +/- 11 mm (range 10 to 72), and 38 lesions (44%) were > or = 20 mm. Twelve patients received an intracoronary stent. The long balloon alone produced angiographic success (< 50% residual stenosis) in 77 lesions (90%). Angiographic success was achieved ultimately in all stenoses, using a stent in 7 patients and a short balloon in 2. There were 2 deaths (2%) and 1 Q-wave myocardial infarction (1%). One patient needed coronary artery bypass surgery. Clinical success without death, Q-wave infarction or bypass surgery was achieved in 83 of 86 procedures (97%). In conclusion, the use of long PTCA balloons with adjuvant stenting produced excellent results in these long stenoses. Lesion length was not a precursor of poor angiographic or clinical outcome.