Target lesion revascularization after wingspan: assessment of safety and durability

A systematic review of clinical and biomechanical engineering perspectives on the prediction of restenosis in coronary and peripheral arteries

Objective

Restenosis is a significant complication of revascularization treatments in coronary and peripheral arteries, sometimes necessitating repeated intervention. Establishing when restenosis will happen is extremely difficult due to the interplay of multiple variables and factors. Standard clinical and Doppler ultrasound scans surveillance follow-ups are the only tools clinicians can rely on to monitor intervention outcomes. However, implementing efficient surveillance programs is hindered by health care system limitations, patients' comorbidities, and compliance. Predictive models classifying patients according to their risk of developing restenosis over a specific period will allow the development of tailored surveillance, prevention programs, and efficient clinical workflows. This review aims to: (1) summarize the state-of-the-art in predictive models for restenosis in coronary and peripheral arteries; (2) compare their performance in terms of predictive power; and (3) provide an outlook for potentially improved predictive models.

Methods

We carried out a comprehensive literature review by accessing the PubMed/MEDLINE database according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search strategy consisted of a combination of keywords and included studies focusing on predictive models of restenosis published between January 1993 and April 2023. One author independently screened titles and abstracts and checked for eligibility. The rest of the authors independently confirmed and discussed in case of any disagreement. The search of published literature identified 22 studies providing two perspectives-clinical and biomechanical engineering-on restenosis and comprising distinct methodologies, predictors, and study designs. We compared predictive models' performance on discrimination and calibration aspects. We reported the performance of models simulating reocclusion progression, evaluated by comparison with clinical images.

Results

Clinical perspective studies consider only routinely collected patient information as restenosis predictors. Our review reveals that clinical models adopting traditional statistics (n = 14) exhibit only modest predictive power. The latter improves when machine learning algorithms (n = 4) are employed. The logistic regression models of the biomechanical engineering perspective (n = 2) show enhanced predictive power when hemodynamic descriptors linked to restenosis are fused with a limited set of clinical risk factors. Biomechanical engineering studies simulating restenosis progression (n = 2) are able to capture its evolution but are computationally expensive and lack risk scoring for individual patients at specific follow-ups.

Conclusions

Restenosis predictive models, based solely on routine clinical risk factors and using classical statistics, inadequately predict the occurrence of restenosis. Risk stratification models with increased predictive power can be potentially built by adopting machine learning techniques and incorporating critical information regarding vessel hemodynamics arising from biomechanical engineering analyses.

Clinical outcomes of different revascularization approaches for patients with multi-vessel coronary artery disease: A network meta-analysis

BACKGROUND

As surgical techniques continue to evolve, the optimal approach for revascularizing multi-vessel coronary artery disease (CAD) remains a matter of ongoing debate. Accordingly, our objective was to compare and contrast various surgical techniques utilized in the management of multi-vessel CAD.

METHODS

A systematic literature review was performed using PubMed, Embase, and Cochrane central register of controlled trials from inception to May 2022. Random-effects network meta-analysis was performed for the primary outcome; target vessel revascularization (TVR), and secondary outcomes; mortality, major adverse cardiac and cerebrovascular events, postoperative myocardial infarction, new-onset atrial fibrillation, stroke, new-onset dialysis, in patients undergoing percutaneous coronary intervention (PCI) with a stent, off-pump coronary bypass graft, on-pump coronary artery bypass graft (ONCABG), hybrid coronary revascularization, minimally-invasive coronary artery bypass, or robot-assisted coronary artery bypass (RCAB) surgeries.

RESULTS

A total of 8841 patients were included from 23 studies. The analysis showed that ONCABG had the highest freedom from TVR, with a mean (SD) absolute risk of 0.027 (0.029); although ONCABG was found to be superior to all other methods, it was only significantly better than first-generation stent PCI. While RCAB did not demonstrate significant superiority over other treatments, it showed a greater probability of preventing postoperative complications. Notably, no significant heterogeneity was calculated for any of the reported outcomes.

CONCLUSIONS

ONCABG shows a better rank probability compared to all other techniques for preventing TVR, while RCAB offers greater freedom from most postoperative complications. However, given the absence of randomized controlled trials, these results should be interpreted with caution.

Tandem Short-length Multi-stent Construct for Emergent Revascularization of Occlusive Long-segment Left Middle Cerebral Artery In-stent Stenosis

Endovascular stenting and balloon angioplasty is a feasible although controversial option for intracranial atherosclerotic stenosis refractory to maximize medical management. High rates of symptomatic in-stent restenosis (ISR) have been identified with Wingspan stent (Stryker, Fremont, CA, USA) placement. Revascularization of ISR by way of re-stenting is often attempted, albeit with high risk and low durability. In lesions with long-segment non-focal critical or emergent occluded stenosis, re-stenting with a single balloon mounted stent is not possible due to deliverability of a lengthy device through a tortuous carotid siphon. Tandem drug-eluting stent placement within the middle cerebral artery to address acute, occlusive ISR using a Wingspan stent, with additional stent reconstruction, has not been previously described.

Intracranial Stenting after Failure of Thrombectomy with the emboTrap® Device

BACKGROUND

Approved alternatives in the guidelines for acute ischemic stroke patients who have failed intracranial thrombectomy are lacking. Primary permanent intracranial stenting was initially used in the era before thrombectomy and might still be a useful rescue treatment in acute stroke patients suffering from ongoing large vessel occlusion refractory to thrombectomy.

METHODS

The prospectively collected registry of patients with acute stroke caused by large vessel occlusions and treated with the emboTrap® device in Karolinska Hospital from October 2013 through March 2017 were retrospectively reviewed. Clinical outcome of non-recanalized patients with a thrombolysis in cerebral infarction (TICI) score of 0-1 after failed thrombectomy were compared with those who were treated with permanent intracranial stenting as rescue therapy. Favorable outcome was defined as modified Rankin scale 0-2.

RESULTS

The emboTrap® device was used in 201 patients. Persistent re-occlusions on withdrawal of the thrombectomy device were seen in 26 patients (13%) and of those, 12 individuals (46%) were treated with intracranial stenting. Baseline National Institutes of Health stroke scale (NIHSS), occlusion site, and onset-to-puncture time did not differ between the stenting group and the non-recanalized group. During the procedure half dose (5/12 patients) or full dose abciximab (6/12 patients), or aspirin (1/12 patient) was given intravenously immediately after stent placement. In 2 patients (17%) multiple stents were implanted. The stenting group had better functional outcomes at 3 months compared to the non-stenting group with 8/12 (66%) vs. 3/14 (21.4%, p < 0.05). Of the patients 5 (36%) in the non-stented group had died at 3 months follow-up, whereas mortality in the stenting cohort was 0% (p < 0.05) and no symptomatic intracranial hemorrhage (ICH) occurred in either group.

CONCLUSION

Intracranial stenting after failure of recanalization with thrombectomy led to a better rate of clinical outcome than leaving the patient non-recanalized. The required antiplatelet therapy, predominantly abciximab, did not lead to additional ICH.

Nonprocedural Symptomatic Infarction and In-Stent Restenosis After Intracranial Angioplasty and Stenting in the SAMMPRIS Trial (Stenting and Aggressive Medical Management for the Prevention of Recurrent Stroke in Intracranial Stenosis)

BACKGROUND AND PURPOSE

The purpose of this study was to investigate the frequency of symptomatic in-stent restenosis (ISR) and its contribution to nonprocedural symptomatic infarction in the SAMMPRIS trial (Stenting and Aggressive Medical Management for the Prevention of Recurrent Stroke in Intracranial Stenosis).

METHODS

Patients without a periprocedural primary end point were followed up to determine the occurrence of any of the following events: ischemic stroke, cerebral infarct with temporary signs, or transient ischemic attack in the territory of the stented artery. Vascular imaging performed after these events was reviewed for ISR. Annual rates for symptomatic ISR were calculated using Kaplan-Meier estimates.

RESULTS

Of 183 patients in the stenting group without a periprocedural primary end point, 27 (14.8%) had a symptomatic infarction (stroke or cerebral infarct with temporary signs) and 16 (8.7%) had transient ischemic attack alone in the territory during a median follow-up of 35.0 months. Of the 27 patients with infarctions, 17 (9.3%) had an ischemic stroke and 10 (5.5%) had a cerebral infarct with temporary signs alone. Adequate vascular imaging to evaluate ISR was available in 24 patients with infarctions (showing ISR in 16 [66.7%]) and in 10 patients with transient ischemic attack alone (showing ISR in 8 [80%]). The 1-, 2-, and 3-year rates (with 95% confidence limits) for symptomatic ISR in the SAMMPRIS stent cohort were 9.6% (6.1%-14.9%), 11.3% (7.5%-17.0%), and 14.0% (9.6%-20.2%), respectively.

CONCLUSIONS

Symptomatic ISR occurred in at least 1 of 7 patients in SAMMPRIS by 3 years of follow-up and was likely responsible for the majority of nonprocedural cerebral infarctions.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT00576693.

Changing Management of Acute Ischaemic Stroke: the New Treatments and Emerging Role of Endovascular Therapy

OPINION STATEMENT

Urgent reperfusion of the ischaemic brain is the aim of stroke treatment, and the last two decades have seen a rapid advancement in the medical and endovascular treatment of acute ischaemic stroke. Intravenous tissue plasminogen activator (tPA) was first introduced as a safe and effective thrombolytic agent followed by the introduction of newer thrombolytic agents as well as anticoagulant and antiplatelet agents, proposed as potentially safer drugs with more favourable interaction profiles. In addition to chemo-thrombolysis, other techniques including transcranial sonothrombolysis and microbubble cavitation have been introduced which are showing promising results, but await large-scale clinical trials. These developments in medical therapies which are undoubtedly of great importance due to their potential widespread and immediate availability are paralleled with gradual but steady improvements in endovascular recanalisation techniques which were initiated by the introduction of the MERCI (Mechanical Embolus Removal in Cerebral Ischemia) and Penumbra systems. The introduction of the Solitaire device was a significant achievement in reliable and safe endovascular recanalisation and was followed by further innovative stent retrievers. Initial trials failed to show a solid benefit in endovascular intervention compared with IV-tPA alone. These counterintuitive results did not last long, however, when a series of very well-designed randomised controlled trials, pioneered by MR-CLEAN, EXTEND-IA and ESCAPE, emerged, confirming the well-believed daily anecdotal evidence. There have now been seven positive trials of endovascular treatment for acute ischaemic stroke. Now that level I evidence regarding the superiority of endovascular recanalisation is abundantly available, the clinical challenge is how to select patients suitable for intervention and to familiarise and educate stroke care providers with this recent development in stroke care. It is important for the interventional services to be provided only in comprehensive stroke centres and endovascular interventions attempted by experienced well-trained operators, at this stage as an adjunct to the established medical treatment of IV-tPA, if there are no contraindications.

Balloons in endovascular neurosurgery: history and current applications

The use of balloons in the field of neurosurgery is currently an essential part of our clinical practice. The field has evolved over the last 40 years since Serbinenko used balloons to test the feasibility of occluding cervical vessels for intracranial pathologies. Since that time, indications have expanded to include sacrificing cervical and intracranial vessels with detachable balloons, supporting the coil mass in wide-necked aneurysms (balloon remodeling technique), and performing intracranial and cervical angioplasty for atherosclerotic disease, as well as an adjunct to treat arteriovenous malformations. With the rapid expansion of endovascular technologies, it appears that the indications and uses for balloons will continue to expand. In this article, we review the history of balloons, the initial applications, the types of balloons available, and the current applications available for endovascular neurosurgeons.

Chinese guidelines for endovascular management of ischemic cerebrovascular diseases

Endovascular technology was initially applied in treating peripheral vascular disease and was further developed in managing coronary artery disease. During the latest two decades, it has been introduced into the arena of cerebrovascular diseases, which has garnered attention and research interests.

Stenting and angioplasty of small cerebral arteries in symptomatic intracranial atherosclerotic disease

BACKGROUND

Intracranial atherosclerotic disease (ICAD) is a common cause of stroke with a poor natural history despite medical therapy. Few studies have investigated endovascular therapies for the treatment of symptomatic ICAD in distal intracranial arteries. Here, we present the feasibility and safety of balloon angioplasty with and without stenting in patients with medically refractory small artery symptomatic ICAD.

METHOD

Personal logs were reviewed to identify patients who were treated for small artery ICAD (stenosis > 50%) using angioplasty ± stenting. Small cerebral arteries were defined by a diameter ≤ 2 mm or any branch distal to a large intracranial vessel (i.e. distal to ICA, M1, A1, Vertebrobasilar trunk). Patient characteristics, clinical manifestations, treatment, hospital course, and follow up data was collected and analyzed.

RESULTS

Ten patients (12 arteries) were treated with either primary balloon angioplasty (58.3%) or angioplasty with stenting (41.6 %) with 100% technical success rate. Mean pre-treatment stenosis was 79.9% while mean post-treatment stenosis was 19.0%. There were no major peri-procedural complications including symptomatic intracranial hemorrhage or mortality; three cases were complicated by groin hematoma. Patients were followed for a mean total of 18.6 months with only one symptomatic restenosis which was re-treated successfully. All patients had good functional outcome with a mRS of either 0 (80%) or 1 (20%) on follow up.

CONCLUSION

In our case series, treatment of symptomatic small artery ICAD with angioplasty ± stenting was safe and effective. These interventions should be considered as an alternative treatment for ICAD patients refractory to medical therapy.

Temporal correlation between wall shear stress and in-stent stenosis after Wingspan stent in swine model

BACKGROUND AND PURPOSE

A recent randomized clinical trial on intracranial atherosclerosis was discontinued because of the higher frequency of stroke and death in the angioplasty and stent placement group than in the medical treatment group. An in-depth understanding of the relationship between biologic responses and flow dynamics is still required to identify the current limitations of intracranial stent placement.

MATERIALS AND METHODS

Five Wingspan stents were deployed in tapered swine ascending pharyngeal arteries. Temporal wall shear stress distributions and in-stent stenosis were evaluated at days 0, 7, 14, and 28 after stent placement. The physiologic role of wall shear stress was analyzed regarding its correlation with in-stent stenosis.

RESULTS

In-stent stenosis reached a peak of nearly 40% at day 14 and decreased mainly at the distal stent segment until day 28. The wall shear stress demonstrated a characteristic pattern with time on the basis of the in-stent stenosis change. The wall shear stress gradient increased from the proximal to distal segment until day 14. At day 28, the trend was reversed dramatically, decreasing from the proximal to the distal segment. A significant correlation between the in-stent stenosis growth until day 14 and low wall shear stress values just after stent placement was detected. In-stent stenosis regression between days 14 and 28 was also associated with the high wall shear stress values at day 14.

CONCLUSIONS

These data suggest that the physiologic wall shear stress can control the biphasic in-stent stenosis change in tapered arteries.

Symptom differences and pretreatment asymptomatic interval affect outcomes of stenting for intracranial atherosclerotic disease

BACKGROUND AND PURPOSE

Different types of symptomatic intracranial stenosis may respond differently to interventional therapy. We investigated symptomatic and pathophysiologic factors that may influence clinical outcomes of patients with intracranial atherosclerotic disease who were treated with stents.

MATERIALS AND METHODS

A retrospective analysis was performed of patients treated with stents for intracranial atherosclerosis at 4 centers. Patient demographics and comorbidities, lesion features, treatment features, and preprocedural and postprocedural functional status were noted. χ(2) univariate and multivariate logistic regression analysis was performed to assess technical results and clinical outcomes.

RESULTS

One hundred forty-two lesions in 131 patients were analyzed. Lesions causing hypoperfusion ischemic symptoms were associated with fewer strokes by last contact [χ(2) (1, n = 63) = 5.41, P = .019]. Nonhypoperfusion lesions causing symptoms during the 14 days before treatment had more strokes by last contact [χ(2) (1, n = 136), 4.21, P = .047]. Patients treated with stents designed for intracranial deployment were more likely to have had a stroke by last contact (OR, 4.63; P = .032), and patients treated with percutaneous balloon angioplasty in addition to deployment of a self-expanding stent were less likely to be stroke free at point of last contact (OR, 0.60; P = .034).

CONCLUSIONS

More favorable outcomes may occur after stent placement for lesions causing hypoperfusion symptoms and when delaying stent placement 7-14 days after most recent symptoms for lesions suspected to cause embolic disease or perforator ischemia. Angioplasty performed in addition to self-expanding stent deployment may lead to worse outcomes, as may use of self-expanding stents rather than balloon-mounted stents.

Higher risk of recurrent ischemic events in patients with intracranial in-stent restenosis

BACKGROUND AND PURPOSE

Reliable data concerning prognosis of patients with intracranial in-stent restenosis (ISR) is lacking. We prospectively studied long-term outcomes of patients with and without a catheter angiography-verified ISR.

METHODS

Between September 2001 and May 2009, 540 consecutive patients with symptomatic intracranial atherosclerosis received stenting treatment at our institute. Of them, 226 patients with 233 stented arteries had catheter angiography follow-up after stenting and were enrolled into this study. They were clinically followed up until the end of December 2011. Primary end point was ischemic stroke or transient ischemic attack in the territory of the stented artery after the catheter angiography follow-up. ISR was defined as a catheter angiography-verified stenosis of ≥50% within or immediately adjacent (within range of 3 mm) to the implanted stent.

RESULTS

During a mean follow-up of 38.9 months, 27 (11.6%, 27/233) primary end point events were recorded. The risk of primary end point in ISR group was higher compared with non-ISR group (21.1% [12/57] versus 8.5% [15/176]; hazard ratio, 2.94; 95% confidence interval, 1.37-6.30; P=0.005). Multivariable analysis showed that the ISR was an independent risk factor for the primary end point (hazard ratio, 2.79; 95% confidence interval, 1.20-6.49; P=0.017). The median occurrence time of primary end point was 9.9 (interquartile range, 5.0, 21.1) months in ISR group, earlier than that in non-ISR group (26.6 [13.1, 52.9] months; P=0.01).

CONCLUSIONS

In-stent restenosis after stenting of intracranial atherosclerosis is significantly associated with an increased risk and an earlier occurrence of recurrent ischemic events in the territory of the stented intracranial artery.

Comparison of Drug-eluting Coronary Stents, Bare Coronary Stents and Self-expanding Stents in Angioplasty of Middle Cerebral Artery Stenoses

Objective

The purpose of this study is to investigate the results of treatment using stent-angioplasty for symptomatic middle cerebral arterial (MCA) stenosis and comparison of in-stent restenosis between drug-eluting stents (DES), bare metal coronary stents (BMS) and self-expanding stents (SES).

Materials and Methods

From Jan. 2007 to June. 2012, 34 patients (mean age ± standard deviation: 62.9 ± 13.6 years) with MCA stenosis were treated. Inclusion criteria were acute infarction or transient ischemic attacks (TIAs) and angiographically proven symptom related severe stenosis. Stents used for treatment were DES (n = 8), BMS (n = 13) and SES (n = 13). National Institutes of Health Stroke Scale (NIHSS) at admission was 2.5 ± 3.1 and mean stenosis rate was 79.0 ± 8.2%. Assessment of clinical and angiographic results was performed retrospectively.

Results

Among 34 patients, periprocedural complications occurred in four cases (11.8%), however, only two cases (6.0%) were symptomatic. All patients were followed clinically (mean follow-up period; 40.7 ± 17.7 months) and 31 were followed angiographically (91.2%. 13.4 ± 8.5 months). There was no occurrence of repeat stroke in all patients; however, mild TIAs related to restenosis occurred in three of 34 patients (8.8%). The mean NIHSS after stent-angioplasty was 1.7 ± 2.9 and 0.8 ± 1.1 at discharge. The modified Rankin score (mRS) at discharge was 0.5 ± 0.9 and 0.3 ± 0.8 at the last clinical follow-up. In-stent restenosis over 50% occurred in five of 31 angiographically followed cases (16.1%), however, all of these events occurred only in patients who were treated with BMS or SES. Restenosis rate was 0.0% in the DES group and 20.8% in the other group (p = 0.562); it did not differ between BMS and SES (2/11 18.2%, 3/13 23.1%, p = 1.000).

Conclusion

Stent-angioplasty appears to be effective for symptomatic MCA stenosis. As for restenosis, in our study, DES was presumed to be more effective than BMS and SES; meanwhile, the results did not differ between the BMS and SES groups.

Wingspan Stenting for Intracranial Atherosclerotic Stenosis

BACKGROUND:

Intracranial atherosclerotic stenosis (ICAS) is responsible for 9% to 37% of ischemic strokes.

OBJECTIVE:

To evaluate the clinical outcome and risk factors for in-stent restenosis (ISR) after treatment of ICAS with a Wingspan stent.

METHODS:

Seventy-seven patients with 79 total target ICAS &gt; 60% (mean, 79.9 ± 8.4%; symptomatic ICAS, 96.2%) underwent attempted treatment with Wingspan stenting between March 2010 and March 2011. A retrospective review of the prospectively registered data was conducted to assess the risk factors for ISR and the clinical outcomes of these patients.

RESULTS:

The 30-day transient ischemic attack/stroke and death rates were 5.3% (95% confidence interval [CI], 0.1-10.5) and 0%, respectively. All patients but 1 were followed up clinically for a mean of 18.9 months (range, 12–23 months). During the period, cumulative transient ischemic attack/stroke and death rates were 8.1% (95% CI, 1.7-14.5) and 0%, respectively. Only 1 patient suffered a disabling stroke (subarachnoid hemorrhage), which was associated with retreatment of an ISR with a drug-eluting balloon-expandable stent. Follow-up angiography was available in 69 treated vessels (89.6%) at 3 to 24 months (median, 12 months). Binary ISR rate was 24.6%, of which 17.6% (3 of 17 cases) was symptomatic. Rapid balloon inflation (95% CI, 5.490-530.817) and longer length of stenosis (95% CI, 1.093-1.891) were independent risk factors for ISR.

CONCLUSION:

Wingspan stenting may be effective for appropriately selected ICAS patients. Rapid balloon inflation and longer lengths of stenosis were independent risk factors for ISR.

Endovascular treatment of symptomatic intracranial atheromatous stenosis: a single center study of 21 consecutive cases

OBJECTIVES

This retrospective single-center study evaluated the technical success as well as the periprocedural and long-term complications of angioplasty with stenting of symptomatic intracranial atheromatous stenosis.

PATIENTS AND METHODS

From January 2005 to December 2010, 21 patients were treated by angioplasty with stent implantation for symptomatic atheromatous intracranial stenosis greater or equal to 50% at least 7 days after a stroke.

RESULTS

The median population age was 65 years (range: 41-88 years), and 76% (16/21) of the candidates had a history of transient ischemic attack (TIA) or stroke before the event qualifying them for an endovascular procedure. In addition, 86% (18/21) were taking antithrombotic medication at the time of the qualifying event. Technical success was obtained in all cases. The periprocedural stroke or death rate was 9.5% (2/21), and there was no other stroke or death after 30 days during the mean follow-up of 1.4 years.

CONCLUSION

Endovascular treatment of symptomatic intracranial atherothrombotic stenosis can lead to severe complications, particularly during the periprocedural period, but it also represents the only alternative treatment for patients who fail with medical therapy. Future studies need to focus on improvement of periprocedural complications. Essentially, this should include more rigorous selection of candidates as well as a better understanding of the pathophysiological mechanism(s) of the ischemic phenomenon related to stenosis.

Intracranial atheromatous disease treatment with the Wingspan stent system: evaluation of clinical, procedural outcome and restenosis rate in a single-center series of 21 consecutive patients with acute and mid-term results

BACKGROUND

Intracranial atherosclerosis may be the underlying pathology in up to 15% of ischemic strokes, but may account for about 40% of strokes in some populations. After an ischemic event determined by intracranial atherosclerosis, patients have a 12% annual risk of stroke recurrence, mostly during the first year.

OBJECTIVE

To evaluate procedural safety, clinical outcome and restenosis rate of Wingspan stent placement.

METHODS

Twenty-one caucasoid patients were enrolled. Target patients were affected by high-grade, symptomatic, intracranial atherosclerotic lesions, were on antithrombotic therapy and at high stroke risk. All patients were treated with the Wingspan stent system.

RESULTS

Technical success resulted 100%, with all target lesions being reduced to <50%. No stroke or death were observed at 30. The mean percent of stenosis was reduced from a middle value of 84% to a middle value of 17% after stent placement. Medium follow-up was 19.5months (range 6-36months). No stroke or death occurred in any patient. None of the patients presented a <50% stent patency rate at follow-up.

CONCLUSIONS

The short-term results and follow up analysis provide evidence demonstrating the safety of the Wingspan system when used in high-risk patient population. Due to concerns regarding long-term stent patency and ischemic events occurrence emerged from clinical trials such as the SAMMPRIS, intracranial angioplasty and stent with the Wingspan system should be considered only for high risk patients in which it may be considered the only viable therapeutic option.

Intensive insulin therapy in brain injury: a meta-analysis

Many studies have addressed the question of whether intensive insulin therapy (IIT) provides better outcomes for brain-injured patients than does conventional insulin therapy (CIT), with conflicting results. We performed a systematic review and meta-analysis of the literature to estimate the effect of IIT on patients with brain injury. We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and citations of key articles and selected "all randomized controlled trials" (RCTs) comparing the effect of IIT to CIT among adult patients with acute brain injury (traumatic brain injury, stroke, subarachnoid hemorrhage, and encephalitis). Of the 2807 studies, we identified 9 RCTs with a total of 1160 patients for analysis. IIT did not appear to decrease the risk of in-hospital or late mortality (RR=1.04, 95% CI=0.75, 1.43 and RR=1.07, 95%CI=0.91, 1.27 respectively). No significant heterogeneity was found (I(2)=0.0%). IIT also did not have a protective effect on long-term neurological outcomes (LTNO) (RR=1.10, 95% CI=0.96, 1.27). IIT, however, did decrease the rate of infections (RR=0.76, 95% CI=0.58, 0.98). Heterogeneity was present (I(2)=64%), which was eliminated upon sensitivity analysis bringing the RR to 0.66 (95% CI=0.55, 0.80, I(2)=0%). IIT increased the rate of hypoglycemic episodes (RR=1.72, 95% CI=1.20, 2.46) however there was intractable heterogeneity present (I(2)=89%), which did not resolve upon sensitivity analysis. We found no evidence of publication bias by Egger's test (p=0.50). To conclude, IIT has no mortality or LTNO benefit to patients with brain injury, but is beneficial at decreasing infection rates.

Coincidental Occurrence of Acute In-stent Thrombosis and Iatrogenic Vessel Perforation During a Wingspan Stent Placement: Management with a Stent In-stent Technique

We presented a case that an acute in-stent thrombosis after the deployment of a Wingspan stent was successfully managed with a stent in-stent technique. Because vessel perforation and subarachnoid hemorrhage were iatrogenically developed during the procedure, we were unable to use the thrombolytic agents to correct the in-stent thrombosis. When a thrombotic complication following an intracranial stent placement occurs with a coincidentally hemorrhagic complication, the stent in-stent technique should be considered as a treatment option.

Endovascular treatment of intracranial stenosis

The Gateway balloon-Wingspan stent system is the first, and currently the only "on-label" device for the treatment of symptomatic intracranial stenosis in the United States. In initial single-arm studies, investigators have indicated that this system can be used for the treatment of symptomatic intracranial atherosclerotic disease with high levels of technical success and acceptable periprocedural complication rates, which are comparable with, or better than, those reported for other endovascular techniques. Intermediate- and long-term follow-up data for patients treated with the Wingspan device remain sparse. We critically review the existing data, which characterize the risk profile and efficacy of endovascular interventions for intracranial atherosclerotic disease, as well as the available clinical evidence that could be used to select appropriate patients for treatment.

Wingspan stents for the treatment of symptomatic atherosclerotic stenosis in small intracranial vessels: safety and efficacy evaluation

BACKGROUND AND PURPOSE

Until now, endovascular treatment of symptomatic atherosclerotic stenosis in small intracranial arteries (≤2.5 mm) was limited. We evaluated the safety and efficacy of the treatment by using Wingspan stents in arteries of this caliber.

MATERIALS AND METHODS

From March 2007 to July 2010, 53 symptomatic intracranial stenoses with narrowing of at least 50% in 53 patients were treated by using Wingspan stents. Clinical manifestations and imaging features were recorded.

RESULTS

The technical success rate was 98.1%. There were no serious complications, with the exception of 1 patient who experienced a small cerebral hemorrhage caused by perforation of microwire. Thirty-nine patients (74%) were available for follow-up imaging with DSA. ISR was documented in 13 of these patients, including 2 patients with symptomatic ISR. The median length of the vascular lesions was 5.39 mm, and patients whose vascular lesions were longer than 5.39 mm had a much higher incidence of ISR than patients whose vascular lesions were shorter than 5.39 mm (53% versus 15%, respectively). The median ratio of the reference artery diameter to the stent diameter was 0.78, and patients whose ratio was smaller than 0.78 had a much higher incidence of ISR than patients whose ratio was larger than 0.78 (53% versus 15%, respectively).

CONCLUSIONS

In our series, percutaneous transluminal angioplasty and stent placement of small intracranial arteries by using Wingspan stents was safe. The ISR rate was relatively high; most patients having ISR were asymptomatic. Further follow-up is needed to assess the long-term efficacy of this procedure.

Intracranial stents for treatment of acute ischemic stroke: evolution and current status

BACKGROUND

Intravascular stents have been applied to treat a variety of pathophysiologic conditions. With advances in stent design and delivery, stenting has become a viable treatment option in neurovascular disease. Recently, intracranial arterial stenting has received increasing interest as a modality to rapidly and effectively recanalize affected vessels in the setting of acute ischemic stroke.

METHODS

To examine the potential of stenting procedures for stroke, we compiled and analyzed relevant experimental and clinical studies in the available databases.

RESULTS

Our resulting discussion covers the brief history of stents, from their initial inception in the 1960s, to the developments of interventional cardiology, and finally to the treatment of acute occlusions of the neurovasculature. We also detail technological advances that have improved stent delivery to intracranial arteries and review the several clinical studies that feature stenting for the treatment of acute ischemic stroke.

CONCLUSION

Numerous clinical studies have revealed that stents are a quick and efficacious endovascular tool for acute ischemic stroke treatment. It appears likely that issues regarding design, safety, and feasibility of stent-based devices will experience further improvement and refinement, and from fruitful criticism of existing technologies and techniques, along with lessons from past mistakes, will arise safer and more effective devices.

How effective is endovascular intracranial revascularization in stroke prevention? Results from Borgess Medical Center Intracranial Revascularization Registry

BACKGROUND AND PURPOSE

The WASID study established the risk of subsequent ischemic stroke at 1 year in subjects with symptomatic intracranial atherosclerotic stenosis (70%-99%) at 18%. The efficacy of different methods of endovascular revascularization in stroke prevention still has not been established. We compared the stroke rate in our registry at 1 year following intervention with the WASID results to identify which method, if any, provides the most benefit in stroke prevention. This result from the BMC-IRR follows a previously published article comparing stent placement and angioplasty outcomes.

MATERIALS AND METHODS

We maintained a nonrandomized single-center single-operator registry of consecutive symptomatic patients who underwent endovascular intracranial revascularization. Data were collected prospectively and retrospectively and analyzed retrospectively. Patients were treated with angioplasty, BMS, or self-expanding WS. To make our data comparable with that in the WASID study, we selected patients with a single lesion of 50%-99% stenosis undergoing a single intervention. Data was collected on patients until symptom recurrence, repeat intervention, or 1 year postintervention, whichever occurred first.

RESULTS

We found that 115 patients fit the inclusion criteria, with 38 angioplasty, 28 BMS, and 49 WS cases. For patients with 70%-99% stenosis, the overall probability of stroke at 1 year postintervention was 19.3%. The overall stroke probability per device, independent of clinical presentation, was 12.5% for angioplasty, 20.2% for BMS, and 24.1% for WS.

CONCLUSIONS

Compared with the WASID data, angioplasty appears to have a lower stroke rate after 1 year than medical therapy alone. However, neither stent-placement arm compared favorably with the WASID results.

Indications and applications of arterial stents for stroke prevention in atherosclerotic intracranial stenosis

Intracranial stenosis accounts for 8-10% of all ischemic strokes in North America, a frequency slightly less than that of extracranial carotid stenosis. Among patients presenting with transient ischemic attack or stroke due to intracranial stenosis, the risk of recurrent stroke in the first year after initial symptoms is about 14%. Those with high-risk features (recent stroke and severe stenosis) have up to a 23% rate of recurrent stroke in the year after their initial event. Angioplasty with stenting has emerged as a potential treatment strategy, particularly in high-risk patients, although evidence is currently limited to uncontrolled prospective trials and retrospective case series. In this article, we critically review the clinical results supporting the use of stenting and highlight some key considerations in the application of this technology, including patient selection, procedural management, technical issues, and risk factors for complications and in-stent restenosis.

U.S. Wingspan Registry: 12-month follow-up results

BACKGROUND AND PURPOSE

The purpose of this study is to present 12-month follow-up results for a series of patients undergoing percutaneous transluminal angioplasty and stenting with the Gateway-Wingspan stenting system (Boston Scientific) for the treatment of symptomatic intracranial atherostenosis.

METHODS

Clinical and angiographic follow-up results were recorded for patients from 5 participating institutions. Primary end points were stroke or death within 30 days of the stenting procedure or ipsilateral stroke after 30 days.

RESULTS

During a 21-month study period, 158 patients with 168 intracranial atherostenotic lesions (50% to 99%) were treated with the Gateway-Wingspan system. The average follow-up duration was 14.2 months with 143 patients having at least 3 months of clinical follow-up and 110 having at least 12 months. The cumulative rate of the primary end point was 15.7% for all patients and 13.9% for patients with high-grade (70% to 99%) stenosis. Of 13 ipsilateral strokes occurring after 30 days, 3 resulted in death. Of these strokes, 76.9% (10 of 13) occurred within the first 6 months of the stenting procedure and no events were recorded after 12 months. An additional 9 patients experienced ipsilateral transient ischemic attack after 30 days. Most postprocedural events (86%) could be attributed to interruption of antiplatelet medications (n=6), in-stent restenosis (n=12), or both (n=1). In 3 patients, the events were of uncertain etiology.

CONCLUSIONS

After successful Wingspan percutaneous transluminal angioplasty and stenting, some patients continued to experience ipsilateral ischemic events. Most of these ischemic events occurred within 6 months of the procedure and were associated with the interruption of antiplatelet therapy or in-stent restenosis.

Wingspan stent for symptomatic M1 stenosis of middle cerebral artery

OBJECTIVE

Stent placement for intracranial atherosclerotic stenosis has become an alternative treatment technique; however, stent placement for middle cerebral artery (MCA) stenosis remains a technical and clinical challenge. Our purpose was to assess the safety and feasibility of Wingspan stent for patients with symptomatic M1 stenosis, and its initial effect on prevention of ischemic events.

METHODS

Fifty-three cases with recurrent symptomatic MCA stenosis resistant to medical therapy treated by self-expanding stent were reviewed retrospectively (average 58±18.5 years old, 19 women). All patients underwent angioplasty and stenting with the Gateway balloon-Wingspan stent system, and advised follow-up with DSA or TCD at 6th month.

RESULTS

Patients had an average stenosis ratio of 76.5±15.4% prior to the treatment. Of the 53 patients, the technical success rate was 98.1% as a whole (52/53). The mean degree of stenosis reduced from (76.5±15.4)% to (18.2±11.3)%. Complications associated with the procedure include subarachnoid hemorrhage (1.89%) and occlusion (3.78%) occurred. During a follow-up of 6 months, there was no recurrence of transient ischemic attack or stroke in 52 cases with successful stenting. Cerebral hemodynamics of MCA using transcranial Doppler monitoring were at normal level (<120 cm/s) in 41 follow-up patients. The follow up angiography at 6 month post-procedure was conducted in 32 patients and showed good patency in stented vessels.

CONCLUSIONS

Wingspan stent for symptomatic stenosis of middle cerebral artery is a safe and feasible procedure. It improves clinical outcome in the intermediate follow up, but its long-term effect remains to be further evaluated.

Treatment of Symptomatic Intracranial Atherosclerotic Stenosis with a Normal-Sized Gateway™ Balloon and Wingspan™ Stent

The safety and performance of angioplasty using a normal-sized Gateway™ balloon and Wingspan™ stent for intracranial atherosclerotic stenosis were assessed. Seventy-two patients with intracranial stenosis (≥ 50%) were treated using an undersized (group U) or normal-sized (group N) Gateway™ balloon and a Wingspan™ stent. All patients were successfully stented. Stenosis improved from 74.2% before treatment to 23.8% immediately after treatment in group U and from 70.9% to 20.1% in group N. The two groups had similar rates of major periprocedural neurological complications (9.0% overall), none of which led to death. Residual stenosis at follow-up was 40.8% and 32.5% in groups U and N, respectively. In-stent re-stenosis (ISR) was significantly less frequent in group N (22.0%) than in group U (33.3%). It is concluded that use of a normal-sized Gateway™ balloon and Wingspan™ stent appears to be safe, to have a high rate of technical success, good immediate post-operative results and a low ISR rate.

Acute ischemic stroke treatment: State of the art

Stroke is among the leading causes of death and serious disability in the United States. Treatment of the acute ischemic stroke patient requires a multidisciplinary approach involving first-responders, emergency department personnel, neurologists, advanced imaging experts and endovascular specialists with neurosurgical support. Contemporary stroke treatment is a rapidly advancing field. New developments in pharmacologic and endovascular stroke therapy require thoughtful trial design and expeditious trial implementation to assess clinical outcomes. This manuscript reviews the state of the art in acute stroke therapy.

Detection of intracranial in-stent restenosis using quantitative magnetic resonance angiography

BACKGROUND AND PURPOSE

In-stent restenosis (ISR) after angioplasty/stenting for intracranial stenosis has been reported in up to 25% to 30% of patients. Detection and monitoring of ISR relies primarily on serial catheter angiography, because noninvasive imaging methods are typically hampered by stent-related artifact. We examined the value of serial vessel flow measurements using quantitative magnetic resonance angiography (QMRA) in detection of ISR.

MATERIAL AND METHODS

Records of patients undergoing stenting for intracranial symptomatic stenosis >50% between 2005 and 2009 were retrospectively reviewed. Angiographic images were graded by a blinded neurointerventionalist for stenosis pretreatment, immediately after treatment, and during follow-up. Flow in the affected vessel measured by QMRA was recorded; > 25% reduction in flow was considered indicative of an adverse change. Clinical data regarding neurological outcome were also collected.

RESULTS

Twenty-eight patients underwent stenting during the time interval studied. Of these, 12 patients (mean age, 55.5 years; 8 female) had contemporaneous angiography and QMRA and were analyzed. Median follow-up was 9 months. Six patients (50%) demonstrated angiographic restenosis 2 to 12 months after treatment; all had an analogous decrease in flow in the vessel of interest. Of 3 patients with more severe flow decrement (> 50%), 2 experienced stroke. None of the patients without angiographic ISR demonstrated a flow decrease on QMRA.

CONCLUSIONS

In this preliminary series, flow decrease on QMRA is highly predictive of angiographic ISR. Additionally, the degree of flow decrement correlates with symptomatic ISR. QMRA may provide a useful noninvasive tool for serial monitoring after intracranial stenting.

Temporary endovascular bypass: a novel treatment for acute stroke

Intracranial stent placement is emerging as an effective treatment for acute stroke. As a means to avoid stent-associated complications and capitalize on stent-placement-related advantages, the concept of a "temporary endovascular bypass" (TEB) for stroke therapy was recently reported. In this technique, a stent is temporarily deployed for instant recanalization. Once sufficient flow is established to maintain vessel patency, the stent is recaptured and withdrawn. We report a second case to further characterize the merits of TEB.