The technique of endovascular intracranial revascularization

Young stroke patient with patent foramen ovale and intracranial stenosis-a case report

The prevalence of patent foramen ovale is approximately 20% in the global population. In patients under the age of 55 years, it has been proven as a cause of acute ischemic embolic stroke of otherwise undetermined source. We present a case of a 25-year-old patient who experienced an acute stroke of dominant hemisphere due to internal carotid artery occlusion.The patient underwent mechanical thrombectomy, followed by acute intracranial stenting due to persistent subocclusion of internal carotid artery. Further diagnostic investigations revealed a significant patent foramen ovale. During subsequent follow-up periods, the patient encountered multiple transient ischemic attacks despite receiving antithrombotic therapy. The indicated angiography examination revealed in-stent stenosis and thrombosis, which were resolved after optimal medical treatment. Following patent foramen ovale closure, the patient remained free from further neurological events during the subsequent two-year follow-up periods. This case emphasizes the necessity of comprehensive diagnostic evaluations in young individuals with stroke and underscores the importance of prudent slection of medical therapies.

Endovascular Therapy for Symptomatic Intracranial Artery Stenosis: a Systematic Review and Network Meta-analysis

Intracranial artery atherosclerotic stenosis (ICAS) is one of the most common causes of stroke. Endovascular therapy including balloon angioplasty alone (BA), balloon-mounted stent (BMS), or self-expanding stent (SES) was an important alternative to treat symptomatic ICAS refractory to medical treatment, while none of the three subtypes has been established to be the primary option. We conducted a systematic review and network meta-analysis to determine both the safety and efficacy and establish a hierarchy of different endovascular therapies on symptomatic ICAS. Major databases including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for studies comparing outcomes of three different endovascular approaches and other comparable non-endovascular therapies for symptomatic ICAS patients published from 1 January 2000 to 1 November 2021. Primary outcomes included short-term mortality or stroke rate (peri-procedural, or mean follow-up ≤ 3 months), and long-term mortality or stroke rate (mean follow-up ≥ 6 months). Pairwise and network meta-analyses based on the above systematic review were conducted. A total of 19 eligible studies involving 3386 patients treated with 4 different approaches (BA, SES, BMS, and medical treatment) were analyzed. For primary outcome, BA had the highest ranking (SUCRA value 78), followed by BMS (SUCRA value 21.5) and SES (SUCRA value 13.1). The short-term mortality or stroke rate was significantly lower in the BA group compared to SES (OR = 2.50; 95% CI 1.12 to 5.57; p = 0.026) or BMS (OR = 0.43; 95% CI 0.19 to 0.96; p = 0.038). Other primary and secondary outcomes were no different among all three types of endovascular therapy. Overall, the studies were of good methodological quality and the consistency was acceptable across all network meta-analyses. BA offers the highest level of safety outcomes in terms of short-term mortality or stroke in treating symptomatic patients with intracranial artery stenosis, compared to SES and BMS, which needs to be confirmed in future studies. Trial registration in PROSPERO database: CRD42018084055.

Improvement of Cerebrovascular Reserve by Percutaneous Transluminal Angioplasty for Symptomatic Middle Cerebral Artery Stenosis

Objective

The purpose of this study was to investigate the efficacy of percutaneous transluminal angioplasty (PTA) for symptomatic middle cerebral artery stenosis by analyzing cerebral blood flow (CBF).

Methods

Between January 2016 and December 2018, six patients with symptomatic middle cerebral artery stenosis underwent CBF analysis by single-photon emission computed tomography (SPECT) with acetazolamide challenge before and after PTA for stenosis. They were retrospectively reviewed, and the blood flow in the area of the affected middle cerebral artery before and after angioplasty was compared.

Results

The mean stenosis rate and length of lesion before angioplasty were 76.4 ± 5.4% and 6.5 ± 2.1 mm, respectively. Balloon angioplasty without stenting was performed on all patients. The mean residual stenosis rate just after angioplasty was 45.4 ± 9.3%. No periprocedual complications developed, and there were no notable cerebral ischemic events during the postprocedural follow-up period. One patient underwent repeat angioplasty for restenosis. Although there was only a mild decrease in blood flow at rest, the cerebrovascular reserve (CVR) in the area of the affected middle cerebral artery was markedly decreased before angioplasty (mean, 3.6 ± 4.3%). After angioplasty, the CVR was significantly improved (mean, 18.0 ± 4.7%, p <0.01).

Conclusions

PTA for symptomatic middle cerebral artery stenosis can be safely performed using appropriate interventional techniques for select patients. Reduced CVR due to stenosis can be improved after angioplasty, which may reduce the risk of cerebral ischemic events.

Endovascular therapy versus medical treatment for symptomatic intracranial artery stenosis

BACKGROUND

Intracranial atherosclerotic stenosis (ICAS) is an arterial narrowing in the brain that can cause stroke. Endovascular therapy and medical management may be used to prevent recurrent ischaemic stroke caused by ICAS. However, there is no consensus on the best treatment for people with ICAS.

OBJECTIVES

To compare the safety and efficacy of endovascular therapy (ET) plus conventional medical treatment (CMT) with CMT alone for the management of symptomatic ICAS.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (30 August 2019), Cochrane Central Register of Controlled Trials (CENTRAL: to 30 August 2019), MEDLINE Ovid (1946 to 30 August 2019), Embase Ovid (1974 to 30 August 2019), Scopus (1960 to 30 August 2019), Science Citation Index Web of Science (1900 to 30 July 2019), Academic Source Complete EBSCO (ASC: 1982 to 30 July 2019), and China Biological Medicine Database (CBM: 1978 to 30 July 2019). We also searched the following trial registers: ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, and Stroke Trials Registry. We also contacted trialists and researchers where additional information was required.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ET plus CMT with CMT alone for the treatment of symptomatic ICAS. ET modalities included angioplasty alone, balloon-mounted stent, and angioplasty followed by placement of a self-expanding stent. CMT included antiplatelet therapy in addition to control of risk factors such as hypertension, hyperlipidaemia, and diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened trials to select potentially eligible RCTs and extracted data. Any disagreements were resolved by discussing and reaching consensus decisions with the full team. We assessed risk of bias and applied the GRADE approach to assess the quality of the evidence. The primary outcome was death of any cause or non-fatal stroke of any type within three months of randomisation. Secondary outcomes included any-cause death or non-fatal stroke of any type more than three months of randomisation, ipsilateral stroke, type of recurrent event, death, restenosis, dependency, and health-related quality of life.

MAIN RESULTS

We included three RCTs with 632 participants who had symptomatic ICAS with an age range of 18 to 85 years. The included trials had high risks of performance bias and other potential sources of bias due to the impossibility of blinding of the endovascular intervention and early termination of the trials. Moreover, one trial had a high risk of attrition bias because of the high rate of loss of one-year follow-up and the high proportion of participants transferred from endovascular therapy to medical management. The quality of evidence ranged from low to moderate, downgraded for imprecision. Compared to CMT, ET probably results in a higher rate of 30-day death or stroke (risk ratio (RR) 3.07, 95% confidence interval (CI) 1.80 to 5.24; 3 RCTs, 632 participants, moderate-quality evidence), 30-day ipsilateral stroke (RR 3.54, 95% CI 1.98 to 6.33; 3 RCTs, 632 participants, moderate-quality evidence), 30-day ischaemic stroke (RR 2.52, 95% CI 1.37 to 4.62; 3 RCTs, 632 participants, moderate-quality evidence), and 30-day haemorrhagic stroke (RR 15.53, 95% CI 2.10 to 115.16; 3 RCTs, 632 participants, low-quality evidence). ET was also likely associated with a worse outcome in one-year death or stroke (RR 1.69, 95% CI 1.21 to 2.36; 3 RCTs, 632 participants, moderate-quality evidence), one-year ipsilateral stroke (RR 2.28, 95% CI 1.52 to 3.42; 3 RCTs, 632 participants, moderate-quality evidence), one-year ischaemic stroke (RR 2.07, 95% CI 1.37 to 3.13; 3 RCTs, 632 participants, moderate-quality evidence), and one-year haemorrhagic stroke (RR 10.13, 95% CI 1.31 to 78.51; 2 RCTs, 521 participants, low-quality evidence). There were no significant differences between ET and CMT in 30-day transient ischaemic attacks (TIA) (RR 0.52, 95% CI 0.11 to 2.35, P = 0.39; 2 RCTs, 181 participants, moderate-quality evidence), 30-day death (RR 5.53, 95% CI 0.98 to 31.17, P = 0.05; 3 RCTs, 632 participants, low-quality evidence), one-year TIA (RR 0.82, 95% CI 0.32 to 2.12; 2 RCTs, 181 participants, moderate-quality evidence), one-year death (RR 1.20, 95% CI 0.50 to 2.86, P = 0.68; 3 RCTs, 632 participants, moderate-quality evidence), and one-year dependency (RR 1.90, 95% CI 0.91 to 3.97, P = 0.09; 3 RCTs, 613 participants, moderate-quality evidence). No data on restenosis and health-related quality of life for meta-analysis were available from the included trials. Two RCTs are ongoing.

AUTHORS' CONCLUSIONS

This systematic review provides moderate-quality evidence showing that ET, compared with CMT, in people with recent symptomatic severe intracranial atherosclerotic stenosis probably does not prevent recurrent stroke and appears to carry an increased hazard. The impact of delayed ET intervention (more than three weeks after a qualifying event) is unclear and may warrant further study.

Intracranial Stenting: Is It Still an Option for Treatment of Patients With Intracranial Atherosclerosis?

Intracranial atherosclerotic disease (ICAD) is considered a major cause of recurrent cerebrovascular events. ICAD continues to be a disease without an effective method of reducing the risk of recurrent stroke and death, even with aggressive, highly monitored medical treatment. We reviewed data from three randomized controlled studies that published data comparing intracranial stenting vs. medical treatment for symptomatic severe-ICAD. Ethnic, demographic, clinical, and procedural differences were observed among the data from these trials that might influence their results. Future research should aim at establishing refined selection criteria that can identify high-risk ICAD patients who may benefit from intracranial stenting.

Efficiency of Air Bubble Removal in Preparation of Low-Profile Angioplasty Balloon Catheter: Bench-Top Comparison of Six Methods

Purpose

Complete removal of air bubbles from balloons for neurovascular angioplasty is cumbersome. We compared the preparation difficulty, air removal efficiency, and air collection pattern of six different balloon catheter preparation methods to propose a better preparation method for both initial and second balloon uses, especially for small-profile angioplasty balloon catheters.Materials and

Methods

A total of 18 neurovascular angioplasty balloon catheters with nominal diameters of 2 mm were prepared to test six different preparation methods: the instruction for use method (method A), simplified method using a syringe (method B) and four newly devised preparation methods using inflating devices (methods C–F). Serial radiographs were obtained while the balloons were gradually inflated. We measured the time for each preparation and the bubble number, analyzed their distribution in the balloon, and calculated the contrast filling ratio (contrast filling area/total balloon area) for initial and second ballooning. The whole process was repeated three times.

Results

The preparation time varied widely (11.5 seconds [method D] to 73.3 seconds [method A]). On initial inflation, the contrast filling ratio at 8 atm was the highest (100%) with methods A and F. On second inflation, the ratio was again highest with method A (99.5%), followed by method F (99.2%). Initial ballooning tended to show a uniform pattern of single bubble in the distal segment of the balloon; in contrast, second ballooning showed varying patterns in which the bubbles were multiple and randomly distributed.

Conclusion

None of the six methods were able to completely exclude air bubbles from the balloon catheters including the second ballooning; however, the method of repeating aspiration with high-volume inflating device (method F) could be a practical option considering the simplicity and efficiency of preparation.

Stenting in Intracranial Stenosis: Current Controversies and Future Directions

Angioplasty and stenting for intracranial atherosclerotic stenosis (ICAS) are a last resort for patients with high-grade intracranial stenosis with multiple ischemic events unresponsive to medical therapy. Medical management, consisting of aggressive risk factor control and dual antiplatelet therapy, is superior to angioplasty and stenting for the prevention of future stroke. Future studies of angioplasty and stenting in this population are important, as the stroke risk on medical therapy is 12 % at 1 year and post-procedure stroke rates are similar to rates with medical treatment. There are many issues that will need to be resolved for stenting to offer any benefit, however. Procedural risks of hemorrhagic and ischemic stroke are unacceptably high. High-risk subgroups, potentially based on hemodynamic factors, will need to be identified for future interventional trials. Nevertheless, it is still reasonable to consider angioplasty and stenting for selected patients with multiple recurrent events despite aggressive medical management, but benefits are unclear at this time.