Stent-unsheathed effect predicts acute distal middle cerebral artery atherosclerotic disease-related occlusion

BACKGROUND

The differentiation of intracranial atherosclerosis (ICAS) and embolism is important.

OBJECTIVE

In cases of ICAS, we observe a phenomenon that we call the "post-stent-deployment effect"; that is, all major branches are clearly visible beyond the occlusion segment when the stent is deployed at the site of occlusion. Our objective is to evaluates whether this post-stent-deployment effect can be used to differentiate ICAS from embolism in the distal M1 segment occlusion.

METHODS

We conduct a retrospective study which reviewed consecutive patients with acute distal M1 segment and in whom recanalization was achieved by endovascular treatment. The post-stent-deployment effect was assessed in these patients. The sensitivity, specificity, positive predictive values (PPV), and accuracy of the post-stent-deployment effect for prediction of ICAS were assessed.

RESULTS

From January 2015 to July 2018, a total of 80 patients were evaluated. The post-stent-deployment effect was more frequently observed in patients with ICAS than in those with embolism (100% vs 15.0%, P < .001). For identifying ICAS in distal M1 segment, the sensitivity, specificity, PPV, and accuracy of the post-stent-deployment effect were 100%, 85.0%, 69.0%, and 88.7%, respectively.

CONCLUSION

Our study finds that the sensitivity and accuracy of the post-stent-deployment effect in predicting distal M1 segment ICAS occlusion in patients with acute symptoms was high, and it may be useful in identifying ICAS lesion.

Microcatheter "First-Pass Effect" Predicts Acute Intracranial Artery Atherosclerotic Disease-Related Occlusion

BACKGROUND

The differentiation between intracranial atherosclerotic stenosis (ICAS) and intracranial embolism as the immediate cause of acute ischemic stroke requiring endovascular therapy is important but challenging. In cases of ICAS, we often observe a phenomenon we call the microcatheter "first-pass effect," which is temporary blood flow through the occluded intracranial artery when the angiographic microcatheter is initially advanced through the site of total occlusion and immediately retrieved proximally.

OBJECTIVE

To evaluate whether this microcatheter first-pass effect can be used to differentiate ICAS from intracranial embolism.

METHODS

A total of 61 patients with acute ischemic stroke resulting from large intracranial artery occlusion and in whom recanalization was achieved by endovascular treatment were included in the study. The microcatheter first-pass effect was tested in these patients. The sensitivity, specificity, positive predictive values (PPV), and accuracy of the microcatheter first-pass effect for prediction of ICAS were assessed.

RESULTS

The microcatheter first-pass effect was more frequently observed in patients with ICAS than in those with intracranial embolism (90.9% vs 12.8%, P < .001). For identifying ICAS, sensitivity, specificity, PPV, and accuracy of the microcatheter first-pass effect were 90.9%, 87.2%, 80.0%, 88.5%, respectively.

CONCLUSION

The sensitivity and PPV of the microcatheter first-pass effect are high for prediction of ICAS in patients with acute symptoms.

Endovascular Therapy Strategy for Acute Embolic Tandem Occlusion: The Pass-Thrombectomy-Protective Thrombectomy (Double PT) Technique

OBJECTIVE

Embolic occlusions of the common carotid artery (CCA)/internal carotid artery (ICA) and intracranial artery occlusions in acute ischemic stroke are associated with high morbidity and can benefit from endovascular therapy. However, the optimal endovascular strategy for these conditions is unclear. This study aimed to evaluate the feasibility of the pass-thrombectomy-protective thrombectomy (double PT) technique and the clinical outcome of treated patients.

METHODS

We collected data on embolic occlusion of the CCA/ICA and intracranial artery occlusion in our prospective stroke registry database between January 2015 and February 2017. Clinical and angiographic data were retrospectively analyzed. Clinical outcome was evaluated at 3 months (modified Rankin scale [mRS] score), and an mRS score of 2 or lower was defined as a good clinical outcome.

RESULTS

A total of 7 patients with tandem occlusion were included, with a mean age of 66 years. The median admission National Institutes of Health Stroke Scale score was 20, and 6 of 7 patients (85.7%) underwent successful recanalization. The median reperfusion time of the affected intracranial artery was 61 minutes. The rate of good clinical outcome was 42.9% (3/7), the mortality rate was 14.3% (1/7), and the embolic event rate was 14.3% (1/7) when the proximal clot was retrieved.

CONCLUSIONS

The double PT technique is feasible and safe in treating initial embolic tandem occlusion of the CCA/ICA.

Another Endovascular Therapy Strategy for Acute Tandem Occlusion: Protect-Expand-Aspiration-Revascularization-Stent (PEARS) Technique

OBJECTIVE

Initial stenotic occlusion of the internal carotid artery with intracranial artery occlusion in acute ischemic stroke is associated with high morbidity and can benefit from endovascular therapy. However, the optimal endovascular strategy is unclear. This study aimed to evaluate the feasibility of the "half" anterograde approach and clinical outcome of treated patients. Revascularization validity of the 2 "half" anterograde approach with (Protect-Expand-Aspiration-Revascularization-Stent [PEARS] technique) or without (plain technique) using an embolic prevention device and aspiration was also compared.

METHODS

Data on initial stenotic occlusion of the internal carotid artery with intracranial artery occlusion in our prospective stroke registry database between January 2015 and February 2017 were collected. Clinical and angiographic data were retrospectively analyzed. Clinical outcome was evaluated at 3 months, defined as a modified Rankin scale ≤2 as a good clinical outcome.

RESULTS

Overall, 26 patients with tandem occlusion were included; 96.3% of patients had successful recanalization. The rate of a good clinical outcome was 61.8%, symptomatic parenchymal hemorrhage was 7.7%, and mortality was 15.4%. The PEARS technique took less time (56 ± 14 vs. 97 ± 31 minutes; P = 0.002) and had less embolic events (0 vs. 30.8%; P = 0.012) compared with the plain technique. Use of the PEARS technique was an independent predictor for shortening revascularization time (β = -0.651, P = 0.001).

CONCLUSIONS

The half anterograde approach technique is feasible and safe for treating tandem occlusion. Furthermore, the PEARS technique is associated with a shorter reperfusion time and less embolic events than the plain technique, and should be recommended in tandem occlusion.

Special Endovascular Treatment for Acute Large Artery Occlusion Resulting From Atherosclerotic Disease

BACKGROUND

Acute intracranial atherosclerotic disease (IAD)-related large artery occlusion (LAO) is typically refractory to mechanical thrombectomy. We evaluated the feasibility and safety of emergency balloon-assisted or stent-assisted angioplasty performed with tirofiban administration for acute IAD-related LAO.

METHODS

We identified, from among 55 consecutive patients who underwent endovascular treatment for LAO, 12 patients with acute IAD-related LAO who underwent balloon-assisted or stent-assisted angioplasty with (n = 3) or without passage of a stent retriever. The treatment included tirofiban administration. We obtained, from patients' clinical records, thrombolysis in cerebral infarction scores (to assess the extent of reperfusion), follow-up magnetic resonance angiography images (to assess patency of the responsive arteries), and 90-day modified Rankin (mRS) scores (to assess outcomes).

RESULTS

Temporary blood flow and severe stenosis were observed angiographically in all 12 patients, either when the stent retriever was deployed or when a microcatheter was advanced through the site of occlusion. Persistent recanalization was achieved in all patients, and there was no operative complication or arterial reocclusion. All 8 patients with an occluded major artery in the anterior circulation had a good outcome, with an mRS score of ≤2. Two of the 4 patients with basilar artery occlusion had a good outcome, with an mRS score of ≤2. One patient (25%) died within 72 hours after procedure.

CONCLUSIONS

Our data point to the safety and feasibility of emergency balloon-assisted or stent-assisted angioplasty performed with tirofiban administration and a single or no passage of the stent retriever for acute IAD-related LAO.

Reversed phase ion-pair liquid chromatographic determination of nicotine in commercial tobacco products. 1. Moist snuff

The official methods for the determination of nicotine in commercial tobacco products (AOAC, CORESTA) are based on approaches that are not selective for nicotine (colorimetric measurement, steam distillation, perchloric acid titration), and the availability of published methods based on state-of-the-art chromatographic methods is limited. Reversed phase ion-pair liquid chromatography has been established as a viable alternative for the analysis of basic analytes. A reversed phase ion-pair liquid chromatographic method for the determination of nicotine in commercial tobacco products was developed and optimized in separate experiments (Ciolino, L. A.; Turner, J. A.; McCauley, H. A.; Smallwood, A. W.; Yi, T. Y. J. Chromatogr. 1999a, 852 (2), 451-463). An extensive within-laboratory performance study of the optimized method was subsequently conducted, and results are presented here for the determination of nicotine in commercial moist snuff. Results for the determination of nicotine in commercial cigarettes are presented in a subsequent paper.

Reversed phase ion-pair liquid chromatographic determination of nicotine in commercial tobacco products. 2. Cigarettes

A reversed phase ion-pair liquid chromatographic method for the determination of nicotine in commercial tobacco products was previously developed and optimized (Ciolino, L. A.; Turner, J. A.; McCauley, H. A.; Smallwood, A. W.; Yi, T. Y. J. Chromatogr. 1999a, 852 (2), 451-463) and provided reliable results for the determination of nicotine in commercial moist snuff (Ciolino, L. A.; McCauley, H. A.; Fraser, D. B.; Barnett, D. Y.; Yi, T. Y.; Turner, J. A. J. Agric. Food Chem. 1999b, 47, 3706-3712). The method uses an aqueous-based sample extraction and provides rapid separation of nicotine from the minor tobacco alkaloids and other commercial tobacco components. In the present work, the method is evaluated for the determination of nicotine in commercial cigarettes and compared to both an official AOAC method for total alkaloids in tobacco (AOAC, AOAC Official Methods of Analysis of AOAC International, 16th ed.; AOAC International: Gaithersburg, MD, 1995; pp 30-31), and a published GC method (Lyerly, L. A.; Greene, G. H. Beitr. Tabakforsch. 1976, 8 (6), 359-361). Good agreement was obtained between the ion-pair LC method and the GC method with relative differences in determined nicotine contents of 0.6 to 5% for a series of commercial and reference cigarettes.

Optimization study for the reversed-phase ion-pair liquid chromatographic determination of nicotine in commercial tobacco products

The availability of published methods for the determination of nicotine in commercial tobacco products based on state-of-the-art chromatographic methods is limited. Nicotine is a diprotic base with pKa's of 3.12 (pyridine ring) and 8.02 (pyrrolidine ring). Other monoprotic and diprotic bases are also present in commercial tobacco including anatabine, nornicotine, anabasine, and cotinine. In this paper, the chromatography of nicotine and the minor tobacco alkaloids under reversed-phase ion-pairing conditions is thoroughly studied. The results of this study are used to understand the retention mechanisms of the tobacco alkaloids, to examine their observed elution order with respect to fundamental analyte properties (size, functionality, and acid-base strength), and to select optimum chromatographic conditions for the determination of nicotine in commercial tobacco products.