Wei-Jian Jiang

Stenting of Symptomatic M1 Stenosis of Middle Cerebral Artery. An Initial Experience of 40 Patients

Objective— To assess the safety and clinical efficacy of stenting for patients with symptomatic M1 stenosis of middle cerebral artery (MCA), and to assess the significance of classification based on location, morphology, and access of intracranial stenosis (LMA classification) in MCA stenting. Methods— Forty patients with 42 symptomatic M1 stenoses refractory to medical therapy were enrolled in this study. The lesions were situated at M1 trunk (n=13), M1 origin (n=12), and M1 bifurcation (n=17), respectively, which were classified into type N (nonbifurcation lesions, n=13) and type A (prebifurcation, n=11), B (postbifurcation, n=14), C (lesion across the nonstenotic ostium of its branch, n=1), D (across the stenotic ostium of its branch, n=2), F (combinative lesions of prebifurcation and its small branch ostium, n=1) locations, morphologically into type A (n=15), B (n=23) and C (n=4) lesions, and into type I (mild-to-moderate tortuosity and smooth access, n=17), II (severe tortuosity and/or irregular arterial wall, n=18), and III (excessively severe tortuosity, n=7) accesses. Results— The technical successful rate was 97.6% for total lesions and 100%, 100%, and 85.7% for types I, II, and III accesses, respectively. The total complication rate was 10%. The mortality was 2.5% (1/40 patients), and 0%, 0%, and 25% for types A, B, and C lesions, respectively. During the median 10 months follow-up, there was no recurrence of transient ischemic attack or stroke in 38 available patients. Among 8 stenting vessels of seven patients with six-month follow-up angiography, 7 showed good patency and one showed restenosis. Conclusion— Stenting appears to be an effective and feasible therapy for symptomatic M1 stenoses, but also appears to have the higher periprocedural complications, which need strict procedural and periprocedural management to reduce the mortality and morbidity. The LMA classification seems to be helpful to work out the individual therapy and predict the results of stenting. A further study is needed to confirm the benefits of stenting of MCA stenosis.

Comparison of elective stenting of severe vs moderate intracranial atherosclerotic stenosis

Objective: To test whether symptomatic severe intracranial atherosclerotic stenosis was associated with a higher subsequent stroke risk than moderate stenosis after elective angioplasty with a balloon-expandable stent and to explore which factors were associated with the subsequent stroke. Methods: Between September 2001 and June 2005, there were 220 symptomatic intracranial atherosclerotic stenoses in 213 patients undergoing elective stenting at our institute. Of these stenoses, 126 in 121 patients were ≥70% severe stenoses, and 94 in 92 patients were 50% to 69% moderate stenoses. Primary endpoints included lesion-related ischemic stroke, and symptomatic brain or subarachnoid hemorrhage. Results: Ten primary endpoint events occurred in the severe stenosis group (six within 30 days and four in mean follow-up of 26.0 months after 30 days), and seven occurred in the moderate stenosis group (four within 30 days and three in mean follow-up of 27.6 months after 30 days). There was no significant difference in cumulative probability of primary endpoints between the severe (7.2% at 1 year and 8.2% at 2 years) and moderate (5.3% at 1 year and 8.3% at 2 years) stenosis groups. No single factor was found to be associated with primary endpoints in the moderate stenosis group. Multivariable analysis revealed that stent failure was the only predictor of primary endpoints in the severe stenosis group (hazard ratio 5.31, 95% CI 1.35 to 20.91). Conclusion: Symptomatic severe intracranial atherosclerotic stenosis did not present a higher subsequent stroke risk than moderate stenosis after elective angioplasty with a balloon-expandable stent. Patients with severe stenosis may benefit from successful stent placement, and randomized trials are necessary to demonstrate this possible benefit.

Outcome of Patients With ≥70% Symptomatic Intracranial Stenosis After Wingspan Stenting

Background and Purpose— There were limited data on the long-term outcome of patients with symptomatic intracranial atherosclerotic stenosis ≥70% after Wingspan stenting. Using our Wingspan cohort data and the data from the Warfarin and Aspirin for Symptomatic Intracranial Atherosclerotic Disease (WASID) as a historical control, we tested the hypothesis that stenting provided no benefit over antithrombotic therapy alone for these high-risk patients. Methods— Between January 2007 and February 2009, 100 consecutive patients with intracranial atherosclerotic stenosis ≥70% and symptoms within 90 days were enrolled into this prospective single-center Wingspan cohort study and followed up until the end of February 2010. Stenosis was measured per the WASID criteria. One-year risk of primary end point (any stroke or death within 30 days and ipsilateral ischemic stroke afterward) was compared with that of ipsilateral ischemic stroke in the WASID patients with ≥70% stenosis. Results— The stent placement success rate was 99%. All patients but 1 had clinical follow-up of ≥12 months. During a mean follow-up of 1.8 years, 9 patients developed primary end point events (5 within 30 days and 4 afterward). The 1-year risk of the outcome events was lower than that in similar WASID patients: 7.3% (95% CI, 2.0% to 12.5%) versus 18% (95% CI, 13% to 24%; P<0.05). Conclusions— The clinical outcome of Wingspan stenting for high-risk intracranial atherosclerotic stenosis patients in this high-volume center study compares favorably with that of antithrombotic therapy alone. A randomized trial comparing medical therapy alone with medical therapy plus Wingspan stenting, conducted at high-volume centers, is needed to confirm the stenting benefit.

Arterial remodeling of advanced basilar atherosclerosis: A 3-tesla MRI study

Background: There are limited studies on wall imaging of human basilar artery (BA). Our aim was to investigate remodeling mode of advanced BA atherosclerosis using 3-T MRI. Methods: Thirty-two consecutive symptomatic patients with atherosclerotic BA stenosis ≥70% were imaged with a 3-T magnetic resonance scanner. Proton density-weighted (PDW) cross-sectional images with submillimeter voxel size were obtained. The vessel area (VA) and lumen area (LA) at the maximal lumen narrowing (MLN) site and reference site were measured. Intraobserver and interobserver variability was determined by intraclass correlation coefficient (ICC). Wall area (WA) was estimated by VA − LA. Plaque size (PS) was estimated by WA at MLN site − reference WA. Percent plaque burden was calculated as (PS/VA at MLN site) × 100%. Remodeling index (RI) was the ratio of VA at MLN site to reference VA. RI ≥1.05 was defined as positive remodeling (PR) and RI <1.05 as non-PR. Results: Measurements of cross-sectional BA images were available in 30 of 32 patients. Intraobserver or interobserver variability was small, with ICC ranging from 0.955 to 0.996. The mean RI of the 30 patients was 1.2 ± 0.4. PR was found in 19 (63.3%) patients and non-PR in 11 (36.7%) patients. Compared with the non-PR group, the PR group had greater PS (15.0 ± 9.3 mm2 vs 6.4 ± 3.9 mm2, p = 0.007) and greater percent plaque burden (50.5 ± 9.9% vs 28.5 ± 12.7%, p < 0.0001). Conclusions: 3-T high-resolution PDW imaging is a reproducible tool for measuring BA dimensions. In patients with advanced BA atherosclerosis, PR lesions are more frequently observed and contain larger plaques than non-PR lesions.

Long-term outcome of elective stenting for symptomatic intracranial vertebrobasilar stenosis.

Seventy-nine consecutive patients with symptomatic atherosclerotic stenosis ≥ 50% of intracranial vertebrobasilar artery (VBA) were treated by elective stenting. There were five strokes within 30 days, and three strokes in the VBA territory after 30 days (mean of 812 days). The annual stroke rate in the VBA territory (including any stroke and death within 30 days) was 4.6%. At the last follow-up time, 73 patients were independent (modified Rankin scale grade ≤ 2). The outcome compares favorably with medical therapy.

Do patients with basilar or vertebral artery stenosis have a higher stroke incidence poststenting

Background and aim Posterior circulation stenosis may be a risk factor associated with stroke after intracranial stenting as compared with anterior circulation stenosis. Our aim was to test our hypothesis that there was no difference in clinical outcome poststenting between patients with severe stenosis of the basilar artery (BA) and intracranial vertebral artery (VA). Methods Using the Cox proportional hazards regression model adjusted for prespecified factors (qualifying event, and timing of stenting after the qualifying event), we compared primary endpoint (ischemic stroke in the vertebrobasilar territory, including any stroke or death within 30 days of stenting) between patients with severe symptomatic atherosclerotic BA and VA stenosis who underwent elective stenting in our prospective database. Analysis was by intention-to-treat principle. Results Primary endpoint event occurred in 13 (18.8%) of 69 patients with BA stenosis during a mean 23.4 months (9 within 30 days and 4 afterward) and 3 (4.3%) of 70 patients with VA stenosis during a mean 26.4 months (2 within 30 days and 1 afterward). Patients with BA stenosis had a significantly higher risk of the primary endpoint (adjusted HR=4.87, 95% CI 1.37 to 17.29; p=0.014) or any stroke or death within 30 days of stenting (adjusted HR=5.13, 95% CI 1.10 to 23.96; p=0.038) than those with VA stenosis. Conclusion A significantly higher stroke risk poststenting exists in patients with severe BA stenosis than those with VA stenosis. The discrepancy in clinical outcome after stenting between patients with BA and VA stenosis should be considered in clinical practice and stenting trials.

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.

Wingspan experience at Beijing Tiantan Hospital: new insights into the mechanisms of procedural complication from viewing intraoperative transient ischemic attacks during awake stenting for vertebrobasilar stenosis

Background and aim Intracranial vertebrobasilar artery (VBA) stenosis portends a stroke and death rate of 8.5–22.8% annually despite medical therapy. Stenting has emerged as a treatment option but also carries substantial risk. Awake stenting under local anesthesia to minimize major procedural complication was investigated. Methods Between January 2007 and December 2008, 43 of 46 consecutive patients with severe symptomatic intracranial VBA stenosis underwent elective angioplasty assisted with self-expanding Wingspan stent under local anesthesia at our institute. All data were collected prospectively. Results All 43 patients tolerated the stenting procedure under local anesthesia well. Forty-two patients (97.7%) were stented successfully. Within 30 days, there were three periprocedural strokes, including thromboembolic infarct, pontine perforator infarct and intracranial hemorrhage, without fatality. In addition, five patients had intraoperative brainstem transient ischemic attacks (TIAs) seconds after the deployment of the stent delivery system across the tortuous VBA. The symptoms and signs included impaired consciousness (n=5), dysarthria (n=3), convulsion (n=2), conjugate horizontal gaze palsy (n=2), nystagmus (n=2) and pinpoint pupils (n=1). There was angiographic evidence of VBA straightening without thromboembolism. The TIAs resolved within minutes of prompt removal of the delivery catheter. Conclusions VBA stenting under local anesthesia is feasible with a 7% periprocedural stroke risk. Awake stenting allows timely detection of intraoperative TIAs. The mechanism of intraoperative TIA appears to be stent delivery system induced VBA straightening and distortion of its vascular tree. A devastating stroke may ensue if the TIA is not detected and distortion of VBA perforators is not reversed promptly.

Safety of Low-Dose Heparin for Intracranial Stent-Assisted Angioplasty: A Randomized Controlled Pilot Study

Purpose: To access the safety of low-dose heparin in comparison to a high-dose regimen in patients undergoing intracranial stent-assisted angioplasty. Methods: Sixty-four consecutive patients (53 men; mean age 54 years) undergoing stent-assisted angioplasty of 70 intracranial arterial stenoses were randomized to receive either low-dose (2000-U bolus+500 U/h) or high-dose (3000-U bolus+800 U/h) intravenous heparin during the procedure. The activated clotting time (ACT) was measured. The groups were compared for the following primary endpoints until hospital discharge: target lesion acute thrombosis, intracranial hemorrhage (ICH), and death. Results: The overall angioplasty success rate was 93% (65/70 lesions). Stents were placed in 94.7% (36/38) and 90.6% (29/32) of patients in the low-dose and high-dose groups, respectively (p=0.65). The primary endpoint occurred in 6% (2/33) of patients in the low-dose group versus 16% (5/31) of patients in the high-dose group (p=0.25). Two patients, 1 patient in each group, experienced acute target lesion thrombosis during the procedure (p=NS); ICH occurred in 5 patients: 1 in the low-dose group and 4 in high-dose group (3.0% versus 12.9%, p=0.19). Conclusion: The use of a low-dose heparin regimen did not increase the incidence of target lesion thrombosis or ICH in this small pilot trial. Intraoperative low-dose heparin seems to be safe for patients undergoing intracranial stent-assisted angioplasty, but these data should be confirmed in a larger trial.