Effects of inflation pressures on mechanical environment of carotid after stent implantation by numerical simulation / 医用生物力学

Objective To investigate the effects of inflation pressures on mechanical environment of pathological carotid after stent implantation. Methods The carotid artery models with lipid and calcified plaques were constructed based on high-resolution MRI images. The artery-stent interaction model was developed in the finite element software. Based on the models, the von Mises stress distributions on the vascular wall and plague under 3 different inflation pressures (909, 1212 and 1515 kPa) were simulated. Results High inflation pressure would induce large Von Mises stress on the artery-stent interface. Moreover, the stress on the lipid plaque increased significantly with the increase of inflation pressure. However, the differences in stress distributions on the calcified plaque were very small under different inflation pressure. Conclusions Higher inflation pressure may severely damage the lipid plaque and artery-stent interface after stenting, which will contribute to the failure of stent. This research finding may provide clinical guidance for the selection of inflation pressure for arterial stent deployment and the assessment of plague stability after stent implantation．

Efficacy of different types of self-expandable stents in carotid artery stenting for carotid bifurcation stenosis / 华中科技大学学报（医学）（英德文版）

Both open and closed loop self-expandable stents were used in carotid artery stenting (CAS) for carotid bifurcation stenosis. We sought to compare the efficacy of two types of stents in CAS. The data of 212 patients treated with CAS (42 and 170 cases implanted with closed and open loop stents, respectively) for carotid bifurcation stenosis and distal filtration protection devices were retrospectively analyzed. Between closed and open loop stents, there were no significant differences in hospitalization duration, NIHSS score before and after the treatment, stenosis at 12th month, and cumulative incidence of primary endpoint events within 30 days or from the 31st day to the 12th month; while there were significant differences in hemodynamic changes and rate of difficulty in recycling distal filtration protection devices. Use of open vs. closed loop stents for carotid bifurcation stenosis seems to be associated with similar incidence of complications, except for greater rate of hemodynamic changes and lower rate of difficulty in recycling the distal filtration protection devices.

Effect of Aortic Arch Type on Technical Indicators in Patients With Carotid Artery Stent Implantation / 中国循环杂志

Objective: To explore the effect of the aortic arch type on technical indicators in patients with carotid artery stent implantation. Methods: We retrospectively analyzed 224 consecutive patients treated in Fu Wai hospital for unilateral carotid artery stent implantation from 2011-01 to 2012-12. We summarized the catheter category, type and the operating techniques including ① retracement, turn and insertion of the catheter, ② retracement, turn of catheter+the guidance of guide wire,③ retracement, turn of catheter+the guidance of guide wire+the supporting of another catheter, ④ using special graphic catheter+the guidance of guide wire+the supporting of another catheter. The procedural X-ray exposure time, dosage of contrast agent and operation related complications were recorded. According to Myla classiifcation, the aortic arches were divided into Myla I, Myla II and Myla III types. Results: There were 7/224 (3.1%) patients with Myla I aortic arch, 113 (50.4%) with Myla II aortic arch and 104 (46.4%) with Myla III aortic arch. A total of 48/104 (46.2%) Myla III patients used special techniques (tech③, tech④), it was more than the patients with Myla I, (1/7,14.3%) and Myla II (17/113, 15.0%), P Myla III was 96.2%, it was lower than those with Myla I (100%) and Myla II (100%), P=0.045. The procedural complication rate in patients with Myla III was 22.1%, it was higher than those with Myla I (0%) and Myla II (8.9%), P=0.007. Conclusion: The aortic arch type is the important inlfuential factor for the techniques used in carotid stent implantation. There were more dififculties and complications for stent implantation in patients with Myla III aortic arch.

The Influence of Anti-Platelet Resistance on the Development of Cerebral Ischemic Lesion after Carotid Artery Stenting

PURPOSE: Cerebral ischemic lesions are frequently observed after carotid artery stenting (CAS), and anti-platelet agents are used to prevent stent thrombosis and peri-procedural complications. However, despite the premedication, cerebral ischemic lesions are observed, suggesting that they may rather be related to anti-platelet resistance. We, therefore, investigated the effects of anti-platelet resistance on the development of cerebral ischemic lesions after CAS. MATERIALS AND METHODS: We retrospectively reviewed patients who received CAS and selected patients for whom brain MRI was performed within 24 hours after CAS and for whom anti-platelet resistance was checked. Anti-platelet resistance was examined by the VerifyNow system. We analyzed the correlation between anti-platelet resistance and cerebral ischemic lesions detected on follow-up MRI. RESULTS: Among 76 patients, 45 (59.2%) developed new ischemic lesions after CAS. Twelve (15.8%) patients showed aspirin resistance and 50 (65.8%) patients showed clopidogrel resistance. Patients with a new ischemic lesion demonstrated a significantly greater frequency of clopidogrel resistance than those who had no new ischemic lesion (82.2% versus 41.9%, p=0.001). The frequency of aspirin resistance was not significantly different between the groups of patients with and without new ischemic lesions (20.0% versus 9.7%, p=0.340). In multivariate analysis, clopidogrel resistance was a significant risk factor for post-procedural cerebral ischemia. CONCLUSION: Anti-platelet resistance can be used to predict new ischemic lesions after CAS. Anti-platelet resistance should be evaluated in all patients prior to CAS to prevent ischemic complications related to CAS.

Clinical Analysis of Carotid Artery Stenting in Symptomatic High-Risk Patients : A Single Stroke Center Study / 대한뇌혈관외과학회지

OBJECTIVE: The early management of patients with acute symptoms due to carotid stenosis remains a subject of debate. Carotid endarterectomy (CEA) has been shown to reduce the risk of stroke in patients with symptomatic extracranial carotid artery stenosis. Carotid artery stenting (CAS) has recently emerged as an alternative to CEA for the primary and secondary prevention of stroke in patients who are at a high risk for complications from surgery. The aim of this study is to evaluate and analyze the clinical outcome of symptomatic high-risk patients with carotid stenosis that was treated with early CAS in a single stroke center. METHODS: From January 2008 to October 2009, we retrospectively analyzed 75 symptomatic high-risk carotid stenosis patients who had been admitted to the stroke center of our neurosurgical department and who were treated with early CAS. Twenty-five patients had transient ischemic attack (TIA) and 50 patients had minor or major stroke and all of them were at a high medical and surgical risk for carotid endarterectomy. They were treated with early CAS as soon as possible (treatment was done within 2 weeks from the onset of symptoms). RESULTS: At three months, 15 patients (20%) in the TIA and stroke group experienced an improvement in their initial neurologic deficit (a decreased modified Rankin scale greater than 2), while in 59 patients (78.4%) the deficit remained stable, and only one patient had a neurological impairment. CONCLUSION: Our data indicates that urgent assessment and early initiation of a combination of existing preventive treatments can reduce the risk of early recurrent stroke after TIA and minor or major stroke in the symptomatic high-risk patients with carotid stenosis.

Rescue Use of Tirofiban for Acute Carotid In-Stent Thrombosis

Carotid artery stenting is widely performed for extracranial carotid artery stenosis. In-stent thrombosis is a rare but potentially devastating complication. We present a case of acute in-stent thrombosis immediately following stent insertion and post-balloon dilatation in a 64-year-old male. Thrombosis was successfully treated by intravenous tirofiban, a glycoprotein IIb/IIIa receptor inhibitor.

Nursing in Period of Surrounding Operation for Carotid Artery Stenting Angioplasty / 中国康复理论与实践

@# ObjectiveTo study the nursing characteristics in surrounding period of operation for treating carotid artery stenosis with stenting angioplasty. MethodsThe nursing procedure for 78 cases with carotid artery stenosis were reviewed to form the duties and items of nursing, including cooperation between doctors and nurses, mentality nursing, instruction of convalescence in the pre-operation, during operation and post-operation. ResultsAll the cases has successfully finished their operative procedure and none serious complication has been found. ConclusionThe nursing play a important role in the stenting angioplasty of carotid artery.

Analysis for Resent Follow-up Results of In-Stent Restenosis in Carotid Artery / 中国普外基础与临床杂志

50; 3 female patients had minor ISRS. Among all factors, female patients had higher incidence of ISRS than male (P=0.038); balloon-expanding after stenting and accompanying with other artherosclerosis of periphery vessel had correlation about ISRS (P=0.037, P=0.016). Conclusion The severe restenosis rate is acceptable. Female patients were more likely to have ISRS. Balloon-expanding maybe have effect on reducing incidence of ISRS and controlling artherosclerosis was helpful.