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ORIGINAL ARTICLE |
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Year : 2016 | Volume
: 53
| Issue : 4 | Page : 211-218 |
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Carotid artery stenting in high-risk patients: a single-center experience
Mohamed K Elewa MD
Department of Neurology, Ain Shams University Hospitals, Ain Shams University, Cairo, Egypt
Date of Submission | 22-Jul-2016 |
Date of Acceptance | 28-Nov-2016 |
Date of Web Publication | 17-Mar-2017 |
Correspondence Address: Mohamed K Elewa Department of Neurology, Ain Shams University Hospitals, Ain Shams University, 38 El-Abbasia, Cairo 11566 Egypt
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/1110-1083.202380
Background Carotid artery stenting (CAS) is a valid alternative to carotid endarterectomy in selected patients. Periprocedural risk of complications is the main determinant for CAS validity. Certain patients’ features may increase the risk of complication. Purpose To assess the management and outcome of the CAS in high-risk patient population. Patients and methods Clinical, treatment, and outcome variables of consecutive high-risk CAS candidates between January 2011 and June 2016 in one center were analyzed. Results Among 29 patients, 21 patients had successful CAS, and only one (3.45%) patient had minor periprocedural stroke. In total, six (20.69%) patients were shifted to carotid endarterectomy, and two (6.90%) patients were managed with medical treatment. Regression analysis showed that bovine arch was independent predictor of CAS infeasibility (P=0.006). The mean follow-up duration was 21.38±15 months. Follow-up duration passed uneventfully. Conclusion CAS in high-risk patients appears to be technically safe. The adverse outcome in high-risk patients is low and accepted. The morbidity and mortality is avoidable with better patient selection and the avoidance of aggressive manipulation whenever possible. CAS should be avoided in patients with certain anatomic risk factors such as type III arch and bovine arch. Keywords: carotid artery stenting, high-risk patients, outcome
How to cite this article: Elewa MK. Carotid artery stenting in high-risk patients: a single-center experience. Egypt J Neurol Psychiatry Neurosurg 2016;53:211-8 |
Introduction | |  |
The role of carotid artery stenting (CAS) in the treatment of patient with significant carotid artery stenosis is growing. The outcome of CAS should be defined with respect to standard carotid endarterectomy (CEA), particularly in low surgical risk patients and high CAS risk patients. The identification of the outcome of high CAS risk patients could improve decision making regarding patient selection. Periprocedural risk of CAS is influenced by patient, device, technique, and operator-related factors. Several clinical and anatomic aspects (other than surgical CEA risk factors) have been stated for increased periprocedural CAS risk in literature, including octogenarians [1],[2],[3], difficult anatomy, type II or III aortic arch and bovine arch, tortuous common carotid artery (CCA), angulated Internal Carotid Artery (ICA) origin, angulated distal ICA and tandem intracranial stenosis [4],[5],[6],[7],[8], some lesion characterestics (subtotal occlusion, long lesions ≥15 mm, ostial centered lesions, and calcified lesions) [8],[9],[10], and contralateral carotid occlusion [6]. Our purpose in the current study is to assess the management and outcome of the CAS in the high-risk patient population.
Patients and methods | |  |
A retrospective review of patients who were candidate for CAS procedures between January 2011 and June 2016 in Suez insurance hospital was performed. Study is retrospective so ethical approval is usually not required as according to Egyptian law the patients acceptance of admission includes a consent to retrospective use of their anonymous data. Eligibility criteria included patients with symptomatic carotid stenosis of greater than or equal to 50% measured by angiography in combination with at least one of the high-risk criteria for CAS according to the literature: age greater than or equal to 80, type II aortic arch, type III aortic arch, bovine aortic arch, tortuous CCA, angulated ICA origin, angulated distal ICA, subtotal occlusion (99% stenosis), long lesions (≥15 mm), concentric calcification, ostial centered lesions, and contralateral carotid occlusion or significant stenosis. All patients had carotid duplex ultrasound assessment, including spectral Doppler, color flow, and gray scale, before the intervention (as a screening tool for the candidates). Brain MRI included diffusion-weighted imaging, T1-weighted imaging, T2-weighted imaging, fluid-attenuated inversion recovery imaging, T2*-weighted gradient-echo imaging, and magnetic resonance angiography (time of flight) before the intervention (as a part of the preoperative assessment). A clinical and neurological examination with assessment by modified Rankin Scale (mRS) was performed before and after the intervention and during the follow-up.
Technique of intervention and periprocedural management
Concomitant therapy
Before CAS, all patients were treated with 150-mg acetylsalicylic acid and received a loading dose of 450-mg clopidogrel, if they were not already taking clopidogrel. After CAS, patients were kept on a daily dose of 150-mg acetylsalicylic acid and 75-mg clopidogrel for 4 weeks. Thereafter, only aspirin was given. During the procedure, 100 U/kg of heparin was given for anticoagulation. Before balloon inflation, 0.5-mg atropine was administered to all patients.
Description of the procedure
All cases were performed via the femoral approach. A guide catheter or long sheath was advanced to the CCA. The culprit lesion was visualized in at least two different projections before and after the procedure. The intracranial circulation was visualized in all patients before and after the procedure.
Embolic protection devices
In all patients, a distal embolic protection devices (EPD) was used. We used SpiderFx embolic protection system (ev3 Endovascular Inc., Plymouth, Minnesota, USA).
Carotid stenting
All lesions were treated with self-expandable nitinol stents. The stents were 30–40 mm in length, and the stent diameter ranged from 6 to 10 mm (either tapered or straight). We used Protégé RX Carotid Stent (ev3 Endovascular Inc.). In tight, subocclusive carotid stenosis, predilation was done using low-profile (2–3 mm in diameter) 0.014-inch wire compatible balloons. After stent placement, postdilatation was done using (3.5-5 mm in diameter) balloons. At the end of the procedure, the arterial introducer was removed, and hemostasis was accomplished by manual compression.
Outcome measures and data analysis
All collected patients data either clinical or angiographical were retrospectively revised. Based on these data, patients were included in the study once they had one or more high-risk features for CAS: octogenarian, difficult anatomy (type II or III aortic arch, bovine arch, tortuous CCA defined as vessel kinking of more than 60°, angulated ICA defined as vessel kinking of more than 60°, and tandem intracranial stenosis), some lesion characteristics (subtotal occlusion=99% stenosis, long lesions ≥15 mm, ostial centered lesions, and calcified lesions), and contralateral carotid occlusion or significant stenosis. Technical success was defined as successful treatment of the stenosis with residual stenosis of less than or equal to 30%. Neurologic outcome was evaluated both at the end of the procedure, before discharge, and during follow-up visits in outpatient clinic (monthly for 6 months and yearly thereafter).
The occurrence of neurological, cardiovascular, and puncture-related complications and death was assessed. Neurological complications were classified as one of the following: minor stroke, new neurological deficit with mRS less than or equal to 2 [11], major stroke, new neurological deficit with mRS greater than or equal to 3, transient ischemic attack (TIA), and new neurological deficit that resolves completely within 24 h.
Data were analyzed using statistical program for the social science (IBM SPSS advanced statistics version 20; SPSS Inc., Chicago, IL). Quantitative data were expressed as mean±SD, median, and interquartile range. Qualitative data were expressed as frequency and percentage. The following tests were used: Wilcoxon’s test of significance was used when comparing between related samples in nonparametric data and Binary logistic regression analysis when assisting the anatomic variables which can affect CAS feasibility. In all tests, P-value less than 0.05 was considered significant, P-value less than 0.001 was considered highly significant, and P-value grater than 0.05 was considered insignificant.
Results | |  |
Most of the patients were males. The mean age was 66.31±8.23 years (range: 53–83 years), with 13.8% of the study population older than 80 years. All the patients were symptomatic (defined as amaurosis fugax, TIA, minor stroke, or major stroke) with median mRS of 2 ([Table 1]).
All patients underwent diagnostic digital subtraction cerebral angiography before CAS ([Table 2]). Anatomical difficulties were found in 21 (72.41%) patients.
Of 29 patients eligible for CAS, 21 (72.41%) CAS procedures were done successfully for 21 patients. In total, six (20.69%) patients were shifted to CEA, and two (6.90%) patients were managed with medical treatment. Technical success was achieved in all 21 (100%) complete procedures. Only one (3.45%) patient developed minor stroke (dysarthria and facial paresis) immediately after the procedure, which later improved completely within 2 days ([Table 3]).
The mean follow-up duration was 21.38±15 months. The range of the follow-up period was 3–60 months. Follow-up duration passed uneventfully ([Table 4]).
Patients showed significant change in their mRS at the last follow-up (P=0.003) ([Table 5]).
Regression analysis showed that bovine arch was an independent anatomical predictor of CAS infeasibility ([Table 6]).
Discussion | |  |
CAS is a valid alternative to CEA in selected patients (patients with high risk for CEA). Among CAS candidates, some have high-risk criteria for CAS, which could raise the possibility of adverse outcome. The current study includes patient population with clinical and angioanatomical high-risk criteria for CAS in an attempt to describe their management, decision making, and outcome. The selected high-risk criteria for CAS were based on the previous published literatures.
In the current study, CAS under distal EPD for the presumed high risk for CAS candidates seems to be safe and within the accepted complication rate (periprocedural risk=3.45%). The European and the American guidelines require periprocedural death or stroke rates to be less than 6% in symptomatic patients [12],[13]. The lower rate of complication in our patient population is explained by the use of distal EPD (filter) in all cases. The use of such devices was repeatedly shown to prevent ipsilateral cerebral thromboembolism and subsequent strokes caused by the detachment of particles from carotid plaque during CAS [14],[15]. A systematic review demonstrated a risk reduction in adverse events amounting to 40% during CAS with the use of distal protection devices [16]. Another factor that may contributes in our low complication rate is the low threshold for procedural abortion and the avoidance of aggressive manipulations in some cases with unfavorable anatomy, literally type III and bovine arch; of six (20.69%) patients shifted to CEA for anatomical factors, five (17.24%) patients had anatomically unfavorable arch type (two cases with type III arch and three cases with bovine arch+left-sided lesion). Type of arch was found to contribute to higher stroke rates in six of the seven studies [6],[7],[8]. Wimmer et al. [8] reported that types II and III arches were predictors of stroke following carotid stenting, whereas Werner et al. [7] found the same with bovine arches. Dumont et al. [19] demonstrated that unfavorable arch anatomy, namely a target vessel taking an acute angle off the arch, was a predictor of perioperative stroke risk. In fact, in certain studies, type III aortic arch was contraindicated for CAS [20].
Our observations regarding anatomical high-risk criteria state that certain anatomical factors may hinder CAS feasibility. Bovine arch was found to be a significant predictor (P=0.006) of CAS infeasibility (only one case underwent technically successful CAS of the four cases) ([Table 6]). Type III arch was associated also with CAS infeasibility but was not found to be significant owing to lack of power (only two cases, and both were shifted to CEA). Type II arch was associated with technical difficulty, but all cases were done successfully without complications (three cases). The Carotid Revascularization Endarterectomy versus Stenting Trial 2 (CREST-2) study will compare outcomes in asymptomatic carotid stenosis patients randomized to best medical treatment (BMT) versus CEA plus BMT versus CAS plus BMT, and patients will be excluded from undergoing CAS if they have a type III arch, severely angled or tortuous innominate artery or CCA, or a severely calcified aortic arch [21]. This goes in the same direction with our findings.
In the current study, certain anatomical characteristics [tortuous CCA, angulated ICA origin, angulated distal ICA, and subtotal occlusion (99% stenosis)] and contralateral carotid occlusion or stenosis were associated with technical difficulties, but they did not affect CAS feasibility or outcome.
Tortuous carotid is found on ∼16% of cerebral angiograms [22], which is similar to the rate of 17.24% found in our patient population. Carotid tortuosity represents a challenge in patients undergoing CAS. Myouchin reported that among 31 symptomatic and asymptomatic carotid artery stenosis patients, successful stenting was not possible in two (6.5%) patients because of severe carotid tortuosity (angles of 60° and 73°) [23]. Faggioli et al. [4] and Fanous et al. [24] found that tortuosity of the CCA and proximal ICA were correlated with both technical failure and increased risk of complications. Tortuous carotid prevents safe passage of distal EPD [25]. Severe tortuosity of the carotid artery was found to be an independent predictor of difficult retrieval for distal EPD [26]. Moreover, the periprocedural risk significantly increased in a study of 262 patients with symptomatic carotid artery stenosis when the angulation between the ICA and the CCA exceeded 60° [27]. Similarly, the stroke risk was correlated with severe tortuosity of the CCA and significant angulation of the ICA origin in an unselected population of 751 patients who underwent 833 CAS procedures [7]. In fact, several authors were forced to abort CAS procedures secondary to severe ICA tortuosity [28],[29],[30].
Despite the presence of difficult distal landing zones (distal ICA tortuosity) in seven (24.14%) patients, which provided technical intraprocedural challenges, all had eventual successful deployment and retrieval of distal EPD, and none of our patients required ICA flow reversal. An anatomically difficult distal landing zone not only makes deployment of protection devices more difficult but also makes the retrieval of these devices more challenging [24],[26]. Reimers et al. [31] reported that the distal EPD could not be advanced beyond the lesion in 10 patients owing to high degree of distal ICA tortuosity and lesion severity in a series of 753 patients who underwent 808 CAS procedures. Fanous et al. [24] reported that despite the successful deployment and retrieval of distal EPD in all cases, the presence of hostile anatomy for the deployment of distal EPD was correlated with increased periprocedural risk among 221 symptomatic patients who underwent CAS.
Critical stenosis (>85%) was previously considered by some authors as a contraindication for CAS [20],[32]. Earlier, critical stenosis was technically challenging, as it impeded the safe advancement of distal EPD [25],[29]. With improvement of the available endovascular devices, stenting of such lesion is no more challenging except for subtotal occlusion (99% stenosis). Subtotal occlusion was associated with increased perioperative risk [9],[24]. In the current study, 10 (34.48%) patients had subtotal occlusion, and all had technically successful CAS without any complications ([Figure 1]) except for one patient who was sent for surgery because of absence of clear lumen compatible with safe stenting. This was associated with well-developed vasavasorum crossing the lesion ([Figure 2]). | Figure 2 Subtotal occlusion with well-developed vasavasorum crossing the lesion.
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Subtotal occlusion with well-developed vasavasorum crossing the lesion.
Extensive calcification either concentric carotid calcification or aortic arch calcification was associated with increased perioperative risk [24],[32],[33],[34],[35]. They were considered a contraindication for CAS in certain studies [9],[20],[36]. In our study, calcified lesions were found in seven (24.14%) patients. Extensive aortic arch calcification was found in three (10.34%) patients.
Octogenarians in the current study represents 13.8% of the studied patient population (three patients) ([Figure 3]). Fortunately they have favorable angioanatomical characteristics, and we did not face any problem while treating them. The previous observations suggest that increased age may be associated with technical failure and higher rate of complications after CAS procedures [1],[37],[38],[39]. The Carotid Revascularization Endarterectomy versus Stent Trial (CREST) trial reported a periprocedural stroke and death rate of 12% among octogenarians compared with 3.23% for nonoctogenarians [1]. Kastrup et al. [40] also reported a combined stroke and death rate of 10% for symptomatic patients greater than 75 years old. This is compared with a rate of less than 3% stroke and death in patients greater than 75 years old. Interestingly, it has been suggested that complex vascular anatomy is more common in the elderly and that when correcting for complex anatomy, old age was no longer a predictor for poor outcome [30],[33],[41],[42]. This explains the reason of favorable outcome of our octogenarian patients. | Figure 3 Subtotal occlusion in an 83-year-old patient before (a) and after stenting (b).
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Our decisions were influenced by the special nature of the stenotic lesion in three cases. The first case was of a 53-years-old female patient who was hypertensive and diabetic. She presented with recurrent hemispheric TIA. The carotid duplex showed left-sided high-grade stenosis. Her diagnostic cerebral angiography (DCA) revealed long stenotic lesion (string sign) with areas of aneurysmal dilatation affecting the left ICA from the carotid bulb till the petrous segment secondary to spontaneous dissection ([Figure 4]). Fair collaterals were seen from the left posterior communicating artery. This patient was treated medically with oral anticoagulation plus control of risk factors, with no more ischemic events during follow-up for 6 months. The second case was of a 61-year-old female patient. She had diabetes and chronic liver disease (Child A). She presented with recurrent hemispheric TIAs. Her DCA showed hypoplastic ICA (CT skull base showed smaller ipsilateral carotid canal in comparison with the other side) with 50% circumferential stenosis with multiple significant intracranial tandem lesions ([Figure 5]). There were fair collaterals from the posterior communicating artery. She was treated medically with double antiplatelet therapy (clopedogril 75+ASA 150) plus aggressive control of risk factors, with no more ischemic events during follow-up of 3 years. The third was a 77-year-old diabetic hypertensive female patient. She presented with ischemic stroke. Her DCA showed subtotal occlusion of the left ICA with no clear stenotic lumen with well-developed vasavasorum crossing the lesion ([Figure 2]). This was associated with extensive calcification of the lesion and the arch. The procedure was aborted, and the patient was sent to a vascular surgeon for opinion. We believe that understanding the nature of the lesion and the multidisciplinary approach are seldom important for better decision making. The conservative attitude is always an option when the risk exceeds benefit. | Figure 4 ICA carotid stenosis secondary to spontaneous dissection in early (a) and late arterial phase (b).
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 | Figure 5 Fifty percent stenosis in hypoplastic carotid artery in early (a) and late arterial phase (b).
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Conclusion | |  |
From the previous data, we can conclude that CAS in high-risk patients appears to be technically safe. The outcome of high-risk patients is accepted. The morbidity and mortality is avoidable with better patient selection and the avoidance of aggressive manipulation whenever possible. CAS should be avoided in patients with certain anatomic risk factors type III arch and left-sided lesions with bovine arch. A large prospective study to definitively evaluate the effect of high-risk factors on CAS feasibility and outcome is needed. Several limitations should be considered before generalization of our results. The retrospective nature and the potential patient selection and treatment bias.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interests.
References | |  |
1. | Hobson RW II, Howard VJ, Roubin GS, Brott TG, Ferguson RD, Popma JJ et al. Carotid artery stenting is associated with increased complications in octogenarians: 30-day stroke and death rates in the CREST lead-in phase. J Vasc Surg 2004; 40:1106–1111. |
2. | Bonati LH, Dobson J, Algra A, Branchereau A, Chatellier G, Fraedrich G et al. Short-term outcome after stenting versus endarterectomy for symptomatic carotid stenosis: A preplanned meta-analysis of individual patient data. Lancet 2010; 376:1062–1073. |
3. | Brott T, Hobson R II, Howard G, Roubin G, Clark W, Brooks W et al. Stenting versus endarterectomy for treatment of carotid-artery stenosis. N Engl J Med 2010; 363:11–23. |
4. | Faggioli GL, Ferri M, Freyrie A, Gargiulo M, Fratesi F, Rossi C et al. Aortic arch anomalies are associated with increased risk of neurological events in carotid stent procedures. Eur J Vasc Endovasc Surg 2007; 33:436–441. |
5. | Madhwal S, Rajagopal V, Bhatt DL, Bajzer CT, Whitlow P, Kapadia SR. Predictors of difficult carotid stenting as determined by aortic arch angiography. J Invasive Cardiol 2008; 20:200–204. |
6. | Sayeed S, Stanziale SF, Wholey MH, Makaroun MS. Angiographic lesion characteristics can predict adverse outcomes after carotid artery stenting. J Vasc Surg 2008; 47:81–87. |
7. | Werner M, Bausback Y, Bräunlich S, Ulrich M, Piorkowski M, Friedenberger J et al. Anatomic variables contributing to a higher periprocedural incidence of stroke and TIA in carotid artery stenting: single center experience of 833 consecutive cases. Catheter Cardiovasc Interv 2012; 80:321–328. |
8. | Wimmer NJ, Yeh RW, Cutlip DE, Mauri L. Risk prediction for adverse events after carotid artery stenting in higher surgical risk patients. Stroke 2012; 43:3218–3224. |
9. | Saw J. Carotid artery stenting for stroke prevention. Can J Cardiol 2014; 30:22–34. |
10. | Morgan CE, Lee CJ, Chin JA, Eskandari MK, Morasch MD, Rodriguez HE et al. High-risk anatomic variables and plaque characteristics in carotid artery stenting. Vasc Endovascular Surg 2014; 48:452–459. |
11. | Crespi V, Braga M, Beretta S, Carolei A, Bignamini A, Sacco S. A practical definition of minor stroke. Neurol Sci 2013; 34:1083–1086. |
12. | European Stroke Organisation, Tendera M, Aboyans V, Bartelink ML et al. ESC Committee for Practice Guidelines. ESC Guidelines on the diagnosis and treatment of peripheral artery diseases: document covering atherosclerotic disease of extracranial carotid and vertebral, mesenteric, renal, upper and lower extremity arteries: the. Eur Heart J 2011; 32:2851–2906. |
13. | Brott TG, Halperin JL, Abbara S, Bacharach JM, Barr JD, Bush RL et al. 2011 ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline on the management of patients with extracranial carotid and vertebral artery disease: executive summary. A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, and the American Stroke Association, American Association of Neuroscience Nurses, American Association of Neurological Surgeons, American College of Radiology, American Society of Neuroradiology, Congress of Neurological Surgeons, Society of Atherosclerosis Imaging and Prevention, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, Society for Vascular Medicine, and Society for Vascular Surgery. Circulation. 2011; 124(4):489–532. |
14. | Wholey MH, Al-Mubarek N, Wholey MH. Updated review of the Global Carotid Artery Stent Registry. Catheter Cardiovasc Interv 2003; 60:259–266. |
15. | Mas JL, Trinquart L, Leys D, Albucher JF, Rousseau H, Viguier A et al. Endarterectomy versus angioplasty in patients with symptomatic severe carotid stenosis (EVA-3S) trial: results up to 4 years from a randomised, multicentre trial. Lancet Neurol 2008; 7:885–892. |
16. | Garg N, Karagiorgos N, Pisimisis GT, Sohal DP, Longo GM, Johanning JM et al. Cerebral protection devices reduce periprocedural strokes during carotid angioplasty and stenting: a systematic review of the current literature. J Endovasc Ther 2009; 16:412–427. |
17. | Kastrup A, Groschel K, Schnaudigel S, Nagele T, Schmidt F, Ememann U. Target lesion ulceration and arch calcification are associated with increased incidence of carotid stentingassociated ischemic lesions in octogenarians. J Vasc Surg 2008; 47:88–95. |
18. | Faggoli G, Ferri M, Rapezzi C, Tonnon C, Manzoli L, Stella A. Atherosclerotic aortic lesions increase the risk of cerebral embolism during carotid stenting in patients with complex aortic arch anatomy. J Vasc Surg 2009; 49:80–85. |
19. | Dumont TM, Mokin M, Wach MM, Drummond PS, Siddiqui AH, Levy EI et al. Understanding risk factors for perioperative ischemic events with carotid stenting: Is age over 80 years or is unfavorable arch anatomy to blame. J Neurointervent Surg 2013; 6:219–224. |
20. | Robbs JV, Mulaudzi T, Paruk N, Pillay B, Rajaruthnam P. Carotid intervention: stent or surgery? A prospective audit. Cardiovasc J Afr 2009; 20:336–339. |
21. | Moore WS. Issues to be addressed and hopefully resolved in the Carotid Revascularization Endarterectomy Versus Stenting Trial 2. Angiology 2016; 67:408–410. |
22. | Derubertis BG, Hynecek RL, Kent KC, Faries PL. Carotid tortuosity in patients with prior cervical radiation: increased technical challenge during carotid stenting. Vasc Endovascular Surg 2011; 45:619–626. |
23. | Myouchin K, Takayama K, Taoka T, Nakagawa H, Wada T, Sakamoto M et al. Carotid Wallstent placement difficulties encountered in carotid artery stenting. Springerplus 2013; 2:468. |
24. | Fanous AA, Natarajan SK, Jowdy PK, Dumont TM, Mokin M, Yu J et al. High-risk factors in symptomatic patients undergoing carotid artery stenting with distal protection: Buffalo Risk Assessment Scale (BRASS). Neurosurgery 2015; 77:531–542; discussion 542–543. |
25. | Eskandari MK, Najjar SF, Matsumura JS, Kibbe MR, Morasch MD. Technical limitations of carotid filter embolic protection devices. Ann Vasc Surg 2007; 21:403–407. |
26. | Lian X, Liu W, Li M, Lin M, Zhu S, Sun W et al. Risk factors and complications associated with difficult retrieval of embolic protection devices in carotid artery stenting. Cardiovasc Intervent Radiol 2012; 35:43–48. |
27. | Naggara O, Touzé E, Beyssen B, Trinquart L, Chatellier G, Meder JF et al. Anatomical and technical factors associated with stroke or death during carotid angioplasty and stenting: results from the endarterectomy versus angioplasty in patients with symptomatic severe carotid stenosis (EVA-3S) trial and systematic review. Stroke 2011; 42:380–388. |
28. | Stankovic G, Liistro F, Moshiri S, Briguori C, Corvaja N, Gimelli G et al. Carotid artery stenting in the first 100 consecutive patients: results and follow up. Heart 2002; 88:381–386. |
29. | Choi HM, Hobson RW, Goldstein J, Chakhtoura E, Lal BK, Haser PB et al. Technical challenges in a program of carotid artery stenting. J Vasc Surg 2004; 40:746–751; discussion 751. |
30. | Lam RC, Lin SC, DeRubertis B, Hynecek R, Kent KC, Faries PL. The impact of increasing age on anatomic factors affecting carotid angioplasty and stenting. J Vasc Surg 2007; 45:875–880. |
31. | Reimers B, Schlüter M, Castriota F, Tübler T, Corvaja N, Cernetti C et al. Routine use of cerebral protection during carotid artery stenting: results of a multicenter registry of 753 patients. Am J Med 2004; 116:217–222. |
32. | Chong PL, Salhiyyah K, Dodd PD. The role of carotid endarterectomy in the endovascular era. Eur J Vasc Endovasc Surg 2005; 29:597–600. |
33. | Bazan H, Pradhan S, Mojibian H, Kyriakides T, Dardick A. Increased aortic arch calcification in patients older than 75 years: implications for carotid artery stenting in elderly patients. J Vasc Surg 2007; 46:841–845. |
34. | Schneider PA, Kasirajan K. Difficult anatomy: what characteristics are critical to good outcomes of either CEA or CAS? Semin Vasc Surg 2007; 20:216–225. |
35. | Setacci C, Chisci E, Setacci F, Iacoponi F, de Donato G, Rossi A. Siena carotid artery stenting score: a risk modelling study for individual patients. Siena carotid artery stenting score: a risk modelling study for individual patients 2010; 41:1259–1265. |
36. | Goldstein LJ, Kahn HU, Sambol EB, Kent KC, Faries PL, Vouyouka AG. Carotid stenting is safe and associated with comparable outcomes in men and women. J Vasc Surg 2009; 49:315–323. |
37. | Petty GW, Brown RD Jr, Whisnant JP, Sicks JD, O’Fallon WM, Wiebers DO. Ischemic stroke subtypes: a population-based study of functional outcome, survival, and recurrence. Stroke 2000; 31:1062–1068. |
38. | Touze E, Trinquart L, Chatellier G, Mas JL. Systematic review of the perioperative risks of stroke or death after carotid angioplasty and stenting. Stroke 2009; 40:e683–e693. |
39. | Dzierwa K, Pieniazek P, Tekieli L, Musialek P, Przewlocki T, Kablak-Ziembicka A et al. Carotid artery stenting according to the “tailored CAS” algorithm performed in the very elderly patients: the thirty day outcome. Catheter Cardiovasc Interv 2013; 82:681–688. |
40. | Kastrup A, Schulz JB, Raygrotzki S, Groschel K, Ernemann U. Comparison of angioplasty and stenting with cerebral protection versus endarterectomy for treatment of internal carotid artery stenosis in elderly patients. J Vasc Surg 2004; 40:945–951. |
41. | Chiam PT, Roubin GS, Iyer SS, Green RM, Soffer DE, Brennan C et al. Carotid artery stenting in elderly patients: importance of case selection. Catheter Cardiovasc Interv 2008; 72:318–324. |
42. | Gribar JJ, Jiddou M, Choksi N, Abbas AE, Bowers T, Kazmierczak C, Timms C et al. Carotid stenting in high-risk patients: early and late outcomes. J Interv Cardiol 2011; 24:247–253. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]
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