Walter A. Tan

Safety, efficacy, and durability of carotid artery stenting for restenosis following carotid endarterectomy: a multicenter study.

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.

Management of Neurological Complications of Carotid Artery Stenting

PURPOSE To review the neurological complications associated with extracranial carotid artery stenting and to preliminarily assess techniques used to manage these complications. METHODS Between April 1994 and August 2000, 450 patients (270 men; mean age 70.2 years, range 27-89) had stents implanted to treat 472 cervical carotid artery stenoses. Over half (257, 57%) of the patients were symptomatic. A variety of stents were implanted percutaneously after predilation of the lesion; a third of the patients received glycoprotein IIb/ IIIa inhibitors intraprocedurally in addition to a standard oral antiplatelet regimen (aspirin and ticlopidine or clopidogrel). Occurrence and management of neurological complications within the 30-day periprocedural period were reviewed. RESULTS There were 14 (3.1%) transient ischemic attacks (TIAs), 10 (2.2%) minor strokes, and 3 (0.7%) major strokes. Among 6 (1.3%) procedure-related deaths, 4 had neurological causes. The total stroke and death rate was 4.2% (n = 19). All the TIAs, 4 of which occurred between 1 and 14 days poststenting, were treated medically, as were the minor strokes, 3 of which occurred >24 hours after stenting. Only 2 minor stroke patients had mild residual upper extremity motor deficits. Intra-arterial thrombolytic therapy was administered in 5 cases (2 major strokes survivors and 3 patients who suffered a neurologically-related death); occlusions were identified in the proximal middle cerebral artery (MCA) in 3 and the distal MCA in 2. Angiographic improvement was noted in 4 (80%), but only the 2 (40%) with distal MCA occlusions did well clinically. CONCLUSIONS Neurological complications following carotid artery stenting are inevitable. The occurrence of minor strokes >24 hours following stenting may indicate a possible late embolic phenomenon, which warrants investigation. Likewise, the marginal efficacy of intra-arterial thrombolytic therapy demonstrates an inability to lyse embolic plaque and underscores the need for effective distal protection.

Evaluation of Glycoprotein IIb/IIIa Inhibitors in Carotid Angioplasty and Stenting

PURPOSE To review the immediate neurological and bleeding complications associated with the use of glycoprotein (GP) IIb/IIIa inhibitors in patients undergoing extracranial carotid artery stent placement. METHODS A retrospective review was performed of 550 patients (321 men; mean age 71.1 years, range 28-91) who underwent carotid artery angioplasty and stent placement. Glycoprotein IIb/IIIa inhibitors were given prophylactically along with heparin to 216 patients, whose outcomes were compared to a control group of 334 patients who received intravenous heparin alone. Primary endpoints were the immediate and 30-day neurological complications, including transient ischemic attacks (TIAs), minor and major strokes, and neurologically-related deaths. The secondary endpoint was any abnormal bleeding. RESULTS The all stroke/neurological death rate in 216 patients treated with heparin and GP IIb/IIIa inhibitors was 6.0% (13 events) compared 2.4% (8 events) in the 334 patients in the heparin-only control group (p=0.0430). Two of the 4 neurologically-related deaths in the GP IIb/IIIa inhibitor group resulted from intracranial hemorrhages; there were no intracranial hemorrhages in the heparin-only group. There was 1 episode of extracranial bleeding in the GP IIb/IIIa inhibitor group treated with embolization. The incidences of significant puncture-site bleeding requiring transfusion were similar in the groups. CONCLUSIONS Neurological complications following percutaneous carotid artery interventions have been relatively few. The neurological sequelae in carotid stent patients receiving glycoprotein IIb/IIIa inhibitors were more numerous and consequential, which suggests that the use of GP IIb/IIIa inhibitors in carotid stenting should be discouraged.

Atherosclerotic Peripheral Vascular Disease Symposium II Intervention for Renal Artery Disease

The primary goal of this American Heart Association renal intervention writing group was to discuss current controversies related to renal interventions and to recommend important areas of clinical research and advocacy initiatives in this peripheral arterial bed. The 4 areas covered in this section include (1) management of asymptomatic renal artery disease, (2) treatment of ischemic nephropathy, (3) prevention and treatment of atheroembolism in renal artery interventions, and (4) treatment of renal in-stent restenosis (ISR). Atherosclerotic renal artery disease is an often unrecognized contributor to refractory hypertension, renal insufficiency, and increased risk of cardiovascular death.1,2 Renal artery disease is associated with increased cardiovascular events (myocardial infarction, stroke, and death), and when associated with symptomatic coronary artery disease, it independently doubles the risk of death.3 Additionally, the presence of bilateral renal artery stenoses is associated with a reduced 4-year survival rate when compared with unilateral disease (47% versus 59%, P <0.001).3 Hypertension, renal insufficiency, and multisystem atherosclerosis are common entities, and the independent occurrence of these conditions is frequent. Thus, the physician must distinguish between association and causation in the evaluation of patients with atherosclerotic renal artery disease and critically appraise the potential for clinical improvement in selecting patients for renal artery intervention. In contrast to other regional manifestations of atherosclerosis, it is impractical to classify patients with atherosclerotic renal artery disease into symptomatic or asymptomatic categories. Two of the cardinal manifestations of renal artery disease, hypertension and renal insufficiency, are frequently “silent” with regard to clinical manifestations until end-organ damage or uremia occurs. Thus, the majority of patients may be deemed asymptomatic. A more appropriate classification of patients with atherosclerotic renal artery disease may be to classify them in relation to potential clinical consequences. We propose the following classification scheme in patients with renal artery disease:

A Comparison of Balloon-Mounted and Self-Expanding Stents in the Carotid Arteries: Immediate and Long-Term Results of More Than 500 Patients

Purpose: To compare the rates of neurological complications and restenosis for balloon-mounted (BM) versus self-expanding (SE) stents deployed in the extracranial carotid arteries. Methods: Among 513 patients (312 men; mean age 71.3 years, range 27–91) who underwent carotid artery stent placement, 496 received 520 stents. The patients were followed with periodic duplex ultrasound examinations; angiography was performed whenever the duplex scan identified a >50% stenosis or symptoms warranted investigation. Periproce-dural data on complications were analyzed on an intention-to-treat basis, while intermediate-term neurological complications were compared in stented patients. Results: In the periprocedural period, there were 19 (3.7%) transient ischemic attacks, 10 (1.9%) minor strokes, 6 (1.2%) major strokes, and 8 (1.6%) deaths among the 513 patients. Five (1.0%) of the deaths were related to neurological complications (3.9% all stroke/neurological death rate). Among the 496 patients receiving 247 (48%) BM stents and 273 (52%) SE stents in 518 arteries, the all stroke/neurological death rates were 3.6% and 4.0%, respectively (p>0.05). During a mean follow-up of 20.6 months (range to 5.6 years), the 3-year freedom from all fatal and ipsilateral nonfatal strokes excluding the 30-day periprocedural period was 95.0% for BM stents and 95.2% for SE devices. Vessel patency (>50%) at 3 years was 92.0% in the population: 96.3% for BM stents and 83.7% for SE stents (p=0.0422). Conclusions: The rate of neurological complications following carotid stenting has been relatively low overall, and no differences were found relative to the type of stent deployed. Vessel patency was excellent at 3 years, with slightly better patency in BM stents, but because of their vulnerability to compression, they will not replace SE stents.

Covered stent for renal artery aneurysm.

This is a case of a 51‐year‐old female with difficult‐to‐control hypertension and a 3‐cm renal artery aneurysm. Successful exclusion of this was performed using a prefabricated stent graft. To our knowledge, this is the first report on the use of a prefabricated covered stent for this indication. Cathet Cardiovasc Intervent 2001;52:106–109.

Techniques, strategies, and dogmas in bifurcation stenting and side branch protection: Some food for thought

Dr. Sakamoto et al. describe a wonderful recipe for retrieving a buddy guidewire from a side branch artery that is entrapped after bifurcation stenting of the main (mother) vessel. They show in their large, meticulous, and well-reported case series that their particular case and equipment selection, retrieval strategy, and execution, in combination, amounted to safe shortand medium-term outcomes [1]. They also reviewed and addressed practical and theoretical concerns and failure modes out to 12 months follow-up [2]. Cased closed? Unfortunately not. It is not difficult to foresee this “Hyogo technique” cited heatedly during a quality or a mortality-and-morbidity (M and M) conference, simultaneously espoused by one camp and condemned by the other: scenario 1—side branch wiring deemed gratuitous, especially when it is associated with a complication, as in entrapped or worse, fractured wire tip [3,4] or scenario 2—side branch wiring deemed standard of care after the fact, in cases when rescue of a stent-occluded branch artery fails. So should we wire side branch arteries more promiscuously? This valuable report provides one answer, but not all answers. Yes, it does show us how to safely retrieve a wire that is trapped alongside a stent. But this specific salvage technique does not pertain to the larger questions of whether to adopt the extra wire strategy in the first place. Most importantly, it did not set out to, nor prove, that this strategy results in better rates of side branch preservation. Like it or not, these debates and practice variation will continue. Similar to food science and cooking, procedural work is part data-driven but in reality is mostly craft and judgment. This means that simply following a great recipe does not always lead to the desired result. We should be constantly aware of the limits and incompleteness of even “scientific” communication. It is difficult enough to put artistic details and subjective aspects of case selection on paper or YouTube, much less replicate. For instance, which patients did they exclude and double-stent up front? Regarding wire retrieval, exactly how much pulling force did the authors apply–10 or 100 dynes? (And how many times? Slow or fast pull, or a combination? With a twist? Clockor counterclockwise?) How about the many other details and nuances of intravascular ultrasound (IVUS) criteria and interpretation, balloon inflation pressures, and so forth? Yet, even if we can not settle what the optimal approach is (except in extremes), at least we should all agree that whatever strategy we adhere to, even a single adverse event should trigger diligent and transparent review. Two or more of these rare events may represent a pattern, and operators should be responsive and humble, be subject to thoughtful scrutiny, and be open to prudent changes in practice. Consider that food-borne poisoning puts everyone on alert, even though this is often inconsequential (in countries with good surveillance and regulations). This is because it can herald fatalities, especially in vulnerable populations such as immunocompromised children or frail elderly patients. Public safety must therefore be an “always event.” This meant a re-examination of my own bias of my “safest” practice of not routinely deploying an extra wire (“keep it simple” principle). I reflected on the past year when even after rotablation and debulking, we still experienced two side branch closures that could not be rewired through the stent. To become exemplary interventionalists, like true master chefs, we take on the responsibility to be vigilant of events and re-evaluate in light of