Abstract
Background
Bilateral carotid artery stenting (BCAS) is often performed in two stages (staged BCAS) but it is also an option to be performed in one stage (simultaneous BCAS). To confirm the safety of simultaneous BCAS, we retrospectively analyzed perioperative and postoperative course of simultaneous BCAS compared with staged BCAS.
Materials and methods
Patients with symptomatic stenosis of ≥50% or asymptomatic stenosis of ≥80% of bilateral carotid arteries underwent BCAS. Procedure time, symptomatic ischemic complications, presence/absence of high-intensity spots on postoperative diffusion-weighted image, duration of postoperative hospital stays and 30 days outcome of patients performed with simultaneous BCAS (group A, 8 patients with 16 stenotic lesions (8 procedures)) were compared with those of staged BCAS (group B, 4 patients with 8 stenotic lesions (8 procedures)).
Results
In groups A and B, procedure time was 146.0 ± 53.8 and 103.5 ± 39.4 min; intraoperative hypotension was observed in 62.5% and 50.0%; postoperative hypotension occurred in 37.5% and 50.0%; diffusion-weighted image showed high-intensity spots in 37.5% and 12.5%; and duration of postoperative hospital stays was 5.1 ± 1.8 and 5.3 ± 2.3 days. No patients suffered symptomatic ischemic complications. In simultaneous BCAS, there was a tendency that procedure time was longer and high-intensity spots on postoperative diffusion-weighted image was more frequent, but there was no increase in symptomatic ischemic complications and duration of hospital stays compared to staged BCAS.
Conclusions
Safety of simultaneous BCAS may not be inferior to staged BCAS. In terms of duration of hospital stays, simultaneous BCAS can be superior to staged BCAS for patients with bilateral carotid artery stenosis.
Keywords: Bilateral carotid artery stenosis, bilateral carotid artery stenting, simultaneous, staged
Introduction
Carotid artery stenosis is one of the leading causes of ischemic stroke.1,2 Carotid artery stenting (CAS) is a useful surgical procedure for treating carotid artery stenosis,3,4 and the number of patients with carotid artery stenosis that are being treated with CAS is increasing since it has been reported to be safe and effective.2,5 Bilateral carotid endarterectomy (CEA), a combination of unilateral CEA and unilateral CAS, or bilateral CAS (BCAS) can all be used to treat bilateral carotid artery stenosis,6–12 but bilateral CEA carries a risk of severe complications due to bilateral disorders of the phrenic pharyngeal nerve, vagus nerve, and/or stellate ganglion.11 For this reason, BCAS or a combination of CEA and CAS has been often selected for bilateral carotid artery stenosis.8–10,12 BCAS can be performed in one (simultaneous BCAS) or two stages (staged BCAS). In comparison with staged BCAS, simultaneous BCAS might increase the risk of intra- or postoperative bradycardia and/or hypotension, due to bilateral baroreceptor stimulation8,12,13 or hyperperfusion syndrome (HPS) resulting from an increase in bilateral intracranial blood flow.9,12 On the other hand, simultaneous BCAS has the advantage of being less expensive and more convenient for patients than staged BCAS.9 We retrospectively analyzed the safety of simultaneous BCAS compared with staged BCAS.
Materials and methods
Patients
From January 2013 to March 2019, 167 CAS procedures were performed in 155 patients with internal carotid artery (ICA) stenosis at our hospital using the dual protection (simultaneous flow reversal and distal filter insertion) and blood aspiration methods, as described previously.14,15 All procedures were performed by interventional neuroradiologists. Twelve patients who had bilateral ICA stenosis with symptomatic ICA stenosis of ≥50% or asymptomatic ICA stenosis of ≥80% (NASCET criteria) were performed BCAS. The characteristics and clinical outcomes of patients performed simultaneous BCAS (group A, 8 patients with 16 stenotic lesions (8 procedures)) were compared with those of patients performed staged BCAS (group B, 4 patients with 8 stenotic lesions (8 procedures)).
Simultaneous BCAS
Multiple antiplatelet drugs (aspirin, 100 mg; clopidogrel, 75 mg; cilostazol, 200 mg; ticlopidine hydrochloride, 200 mg) were administered for at least one week before the CAS. The antiplatelet agent was administered in 14 procedures for aspirin, 14 procedures for clopidogrel, 9 procedures for cilostazol, and 2 procedures for ticlopidine hydrochloride. During the procedure, heparin was administered to maintain an activating clotting time of more than 275 s. Under local anesthesia, a 9 Fr occlusion balloon-guiding catheter (OPTIMO; Tokai Medical Products, Aichi, Japan) was introduced into the common carotid artery (CCA) via the femoral artery, and a balloon wire system (GuardWire; Medtronic, Minneapolis, MN) was placed in the external carotid artery. The proximal end of the 9 Fr occlusion balloon-guiding catheter and a 4 Fr indwelling sheath in the femoral vein were connected via the blood filter. Under flow reversal, a filter wire (FilterWire EZ; Boston Scientific, Natick, MA) was passed across the lesion and deployed into the high cervical ICA. Pre-dilation, self-expanding stent (Carotid Wallstent; Boston Scientific in all cases) deployment, and post-dilatation were performed under dual protection. Post-dilatation was performed with the diameter of the distal normal internal carotid artery under the use of an angioplasty balloon, the balloon is slowly expanded for about 10 s. An aspiration catheter (Export aspiration catheter; Medtronic) was then placed between the proximal end of the stent and the distal filter, and blood was aspirated several times from the ICA. Subsequently, a 9 Fr occlusion balloon-guiding catheter was introduced into the contralateral CCA. The contralateral CAS was conducted in the same way. Argatroban was continuously administered at a rate of 2.5 mg/h for 12 h after the procedure. The symptomatic side was treated first in the unilaterally symptomatic patients, whereas the side that displayed the most marked stenosis was treated first in the bilaterally symptomatic and asymptomatic patients.
Staged BCAS
After CAS had been performed on one side in the first procedure, the patient was discharged. The patient was then hospitalized again, and CAS was carried out on the contralateral side in the second procedure, which was conducted as described above.
Definition and management of hemodynamic depression
Intra- and postoperative HD, i.e., bradycardia and/or hypotension, were defined as a heart rate of ≤60 beats/min and/or a systolic blood pressure level of ≤100 mmHg. During the procedure, the patient’s heart rate was measured using electrocardiography, and their blood pressure was evaluated through the sheath in the femoral artery. After the procedure, electrocardiographic monitoring was continued, and non-invasive blood pressure measurements were obtained every 15 min until at least 24 h.
Before the stenting, 0.5 mg of atropine sulfate was administered prophylactically. In cases in which intra-operative hypotension occurred, 1 mg of etilefrine was administered intermittently. In cases in which postoperative HT arose, etilefrine was infused continuously to maintain a systolic blood pressure of ≥100 mmHg.
Postoperative evaluation
Clinical outcomes
We assessed the pre-planned procedure completion rate, the procedure time (time to be required for one procedure), symptomatic ischemic complications in perioperative period, the frequencies of intra- and postoperative HD, the presence/absence of high-intensity lesions on postoperative diffusion-weighted image (DWI), the duration of the postoperative hospital stays, and 30 days outcome. The procedure time was defined as the time from puncture to sheath removal for one procedure. The duration of postoperative HD was defined as the length of the postoperative vasopressor treatment period. HPS was defined as exhibiting symptoms such as an ipsilateral throbbing headache, nausea, vomiting, or focal nerve symptoms without cerebral infarction on radiographic imaging, as reported previously.16 DWI scans were acquired within the three days before and after the CAS procedure and were compared to detect CAS-related hyperintense lesions. Thirty days outcome was assessed with post-operative ischemic complication, myocardial infarction, and death within 30 days after procedure.
Statistical analyses
The JMP software V.14 (SAS Institute, Cary, NC) was used for all statistical analyses, and continuous variables are expressed as mean ± standard deviation (SD) values. Median values and the range were computed as appropriate. Fisher's exact test was used for analyses of categorical data, and continuous variables were analyzed using Mann–Whitney's U test; p < 0.05 was considered significant.
Results
Patients’ characteristics
Table 1 shows the characteristics of the patients. The mean age of the patients was 70.3 ± 7.5 years. Eleven of the patients were male, 8 had hypertension, 3 had diabetes mellitus, 11 had dyslipidemia, 6 had ischemic heart disease, 11 were current smokers, and 9 were alcohol consumers. Ten of 24 lesions were symptomatic stenosis. There was no significant difference between simultaneous and staged BCAS in the degree of pre-operative stenosis in symptomatic and asymptomatic cases. The patients’ characteristics between the two groups were nearly equivalent.
Table 1.
Characteristics of 12 patients and 24 lesions.
| Simultaneous BCAS (group A) | Staged BCAS (group B) | ||
|---|---|---|---|
| (8 patients/ 16 lesions) | (4 patients/ 8 lesions) | p value | |
| Mean age, years (mean ± SD) (n) | 70.4 ± 7.3 (8) | 70.3 ± 9.0 (4) | 0.98 |
| Men, n/N (%) | 7/8 (87.5%) | 4/4 (100%) | 1.00 |
| Hypertension, n/N (%) | 6/8 (75.0%) | 2/4 (50.0%) | 0.55 |
| Diabetes mellitus, n/N (%) | 3/8 (37.5%) | 0/4 (0%) | 0.49 |
| Dyslipidemia, n/N (%) | 7/8 (87.5%) | 4/4 (100%) | 1.00 |
| Ischemic heart disease, n/N (%) | 3/8 (37.5%) | 3/4 (75.0%) | 0.55 |
| Smoking, n/N (%) | 7/8 (87.5%) | 4/4 (100%) | 1.00 |
| Alcoholism, n/N (%) | 6/8 (75.0%) | 3/4 (75.0%) | 1.00 |
| Symptomatic lesions, n/N (%) | 7/16 (43.8%) | 3/8 (37.5%) | 1.00 |
| Degree of pre-operative stenosis | |||
| Symptomatic side (median, (range)) (%) (n/N) | 90 (50–99) (7/16) | 70 (70–90) (3/8) | 0.87 |
| Asymptomatic side (median, (range)) (%) (n/N) | 80 (80–85) (9/16) | 80 (80–90) (5/8) | 0.52 |
BCAS: bilateral carotid artery stenting.
Postoperative clinical outcomes
Table 2 shows the patients’ postoperative clinical outcomes. There was no significant difference between simultaneous and staged BCAS in the degree of post-operative stenosis in symptomatic and asymptomatic cases. In staged BCAS, the contralateral CAS was performed a median of 47 days (21–84 days) after the primary CAS. All procedures were completed without being stopped halfway due to intraoperative adverse events, and no symptomatic ischemic complications were seen in any case. The mean time required for one procedure was 146.0 ± 53.8 min in group A and 103.5 ± 39.4 min in group B. Intraoperative bradycardia was observed 12.5% in group A and none had postoperative bradycardia in group B. Intraoperative hypotension was observed in five out of eight procedures (62.5%) in group A and four out of eight procedures (50.0%) in group B. Among the four cases in which intraoperative hypotension occurred in group A, blood pressure decreased in two cases after the first stent placement, but CAS on the contralateral side could be performed under administration of a vasopressor. Postoperative hypotension occurred in three out of eight procedures (37.5%) in group A and four out of eight procedures (50.0%) in group B. The median of duration of the postoperative HD was 0 h (range; 0–20) in group A and 12 h (range; 0–45) in group B. No clinically symptomatic HPS occurred in any case. There were no cases in which surgery was interrupted due to intraoperative adverse events in both groups. On postoperative DWI, multiple high-intensity spots were recognized in three out of eight procedures (37.5%) (2 of which were bilateral lesions) in group A and one out of eight procedures (12.5%) (treatment side) in group B. All DWI positive lesions were less than 1 mm in diameter and the median of number of DWI positive spots were seven (range 2–7) in group A and four (4) in group B. The mean duration of the postoperative hospital stays was 5.1 ± 1.8 days in group A and 5.3 ± 2.3 days in group B. Although there was a tendency that the mean time required for one procedure was longer and the incidence of postoperative multiple DWI high-intensity spots was higher in group A than in group B. No patients had symptomatic ischemic stroke, myocardial infarction, or death within 30 days. There was no increase in the frequency of symptomatic ischemic complications, frequency of intraoperative or postoperative HD, the frequency of HPS, prolongation in the duration of postoperative hospital stays period, and poor post-operative course in group A compared with group B.
Table 2.
Postoperative clinical outcomes.
| Simultaneous BCAS (group A) | Staged BCAS (group B) | p value | |
|---|---|---|---|
| (8 patients/16 lesions) | (4 patients/8 lesions) | ||
| Degree of post-operative stenosis | |||
| Symptomatic side (median, (range)) (%) (n/N) | 0 (0–30) (7/16) | 0 (0–10) (3/8) | 0.26 |
| Asymptomatic side (median, (range)) (%) (n/N) | 10 (0–35) (9/16) | 0 (0–30) (5/8) | 0.84 |
| Procedure completion, n/N (%) | 8/8 (100%) | 8/8 (100%) | 1.00 |
| Procedure time (mean ± SD) (min) (n) | 146.0 ± 53.8 (8) | 103.5 ± 39.4 (8) | 0.22 |
| Symptomatic ischemic complications, n/N (%) | 0/8 (0%) | 0/8 (0%) | 1.00 |
| Intraoperative HD, n/N (%) | 5/8 (62.5%) | 4/8 (50.0%) | 1.00 |
| Postoperative HD, n/N (%) | 3/8 (37.5%) | 4/8 (50.0%) | 1.00 |
| Duration of postoperative HD (median, (range)) (h) (n) | 0 (0–20) (3) | 12 (0–45) (4) | 0.23 |
| HPS, n/N (%) | 0/8 (0%) | 0/8 (0%) | 1.00 |
| DWI positive, n/N (%) (median (range)) | 3/8 (37.5%) (7 (2–7)) | 1/8 (12.5%) (4 (4)) | 0.57 |
| Duration of postoperative hospital stay (mean ± SD, days) (n) | 5.1 ± 1.8 (8) | 5.3 ± 2.3 (8) | 1.00 |
| Adverse event within 30 days | 0/8 (0%) | 0/8 (0%) | 1.00 |
BCAS: bilateral carotid artery stenting; HD: hemodynamic depression; HPS: cerebral hyperperfusion syndrome; DWI: diffusion-weighted image; SD: standard deviation.
Representative case performed with simultaneous BCAS
Simultaneous BCAS was performed on a 67-year-old male with symptomatic bilateral internal carotid stenosis. The preoperative angiography showed severe stenosis of the bilateral cervical internal carotid artery (Figure 1(a) and (b)). The degree of stenosis was higher on the right side than the left side, right side CAS was performed first. Under dual protection, an 8 × 21 mm self-expanding stent (Carotid Wallstent) was deployed and post-dilatation was performed using 5.0 × 30 mm angioplasty catheter. After stent placement, the systolic blood pressure decreased from 120 mmHg to the 60 mmHg. Therefore, intravenous administration of etilefrine was started, and the systolic blood pressure was improved to 100 mmHg. Since the plaque protrusion was detected by angiography and intravascular ultrasound, the additional stent was deployed. Systolic blood pressure was kept at 100 mmHg by sustained administration of etilefrine, we continued left side CAS. Under dual protection, an 8 × 21 mm self-expanding stent (Carotid Wallstent) was deployed and post-dilatation was performed using 5.5 × 30 mm angioplasty catheter. After placing the stent and post-dilatation, the blood pressure did not decrease (Figure 1(c)). There was no residual stenosis on bilateral cervical lesions after BCAS (Figure 1(d) and (e)). Total procedure time was 176 min. After surgery, prolonged hypotension was observed, and continuous administration of etilefrine was required for 18 h. Although DWI on the day after simultaneous BCAS showed high-intensity spots scattered in bilateral cerebral hemispheres (Figure 1(f)), symptomatic cerebral ischemic complications and HPS did not occur. He was discharged on third postoperative day.
Figure 1.
Representative case with simultaneous BCAS. The preoperative lateral images of DSA presented severe stenosis in the bilateral ICA (a right side, b left side). The degree of stenosis on the right ICA was higher than that on the left ICA. (c) The course of intraoperative BP, (˅: systolic blood pressure, ˄: diastolic blood pressure) and HR (▪). Although the BP decreased after placing the stent on the right side, the left side stent placement was also continued by the administration of the vasopressor agent. The postoperative lateral images of DSA showed no residual stenosis on bilateral ICA after BCAS (d right side, e left side). High-intensity spots scattered in bilateral cerebral hemispheres on DWI the day after simultaneous BCAS (f). DSA: digital subtraction angiography; ICA: internal carotid artery; BP: blood pressure; HR: heart rate; BCAS: bilateral carotid artery stenting; DWI: diffusion-weighted imaging.
Discussion
In our study, the safety of simultaneous BCAS may not be inferior to that of staged BCAS, and the duration of postoperative hospital stays in simultaneous BCAS was not extended as compared with the staged BCAS. Therefore, in terms of the duration of hospital stays for BCAS simultaneous BCAS can be superior to staged BCAS for patients with bilateral carotid artery stenosis.
Carotid artery stenosis is one of the leading causes of ischemic stroke and is reported to account for 15–25% of all ischemic strokes.1,2 CAS has been reported to be a safe and effective surgical procedure for carotid artery stenosis,3,4 and the number of cases of carotid artery stenosis in which CAS is employed is increasing.2,5 Bilateral carotid stenosis was observed in 51% of patients who underwent unilateral CAS,17 and about 15% of patients who undergo unilateral surgical treatment subsequently need surgical treatment on the contralateral side.12,17 Before the safety and effectiveness of CAS was established, bilateral CEA was enforced,6,7 but it carries a risk of severe complications due to bilateral disorders of the phrenic pharyngeal nerve, vagus nerve, and/or stellate ganglion.11 For this reason, recently BCAS or a combination of CEA and CAS has often been selected for bilateral carotid artery stenosis.8–10,12 Compared with a combination of CEA and CAS, BCAS is minimally invasive and involves a shorter interval between the procedures on each side.10 When performing BCAS, treatment can be conducted in a simultaneous or staged manner. Although BCAS was performed in a staged manner in previous studies due to the risk of bradycardia, hypotension, or HPS,12,18,19 there are some disadvantages to this approach, such as increased expenditure, the inconvenience to patients for multiple procedures, and the fact that the treatment of the contralateral carotid artery is delayed.9 Compared with staged BCAS, simultaneous BCAS has the advantage of being cheaper and more convenient,9 and its safety and effectiveness have been confirmed.8,9,18,20
The incidence of perioperative HD during ipsilateral CAS has been reported to be around 40%,21–23 and prolonged postoperative HD occurs in 11.4 to 28.3% of cases.8,13,21–24 The length of the stenotic lesion,21 calcification,25 a calcified plaque in the carotid bulb,22 stenosis close to the carotid bifurcation,26 the use of balloon-expandable stents,24 overlapping stents,23 stenosis on the contralateral side,21 and a history of myocardial infarction13 have all been reported to be risk factors for intra- and postoperative HD. In BCAS, Li et al. reported that the post-procedural systolic blood pressure of simultaneous BCAS was lower than that of staged BCAS, the incidence of intraoperative HD was 57.1% in simultaneous BCAS and 57.7% in staged BCAS, and prolonged postoperative HD was observed after 26.2% of simultaneous BCAS procedures and 19.2% of staged BCAS procedures, but the difference is not significant.9 The incidence of intraoperative and postoperative HD on simultaneous BCAS was not increased compared to staged BCAS and of the cases with HD in simultaneous BCAS, only half of the cases occurred after the second stent placement that stimulate bilateral baroreceptor in our study. Thus, simultaneous BCAS does not necessarily seem to be a risk factor for HD. Even if the HD occurred after the CAS on one side, the CAS on the other side could continue using the vasopressor, and it was considered that HD would not be a factor to interrupt the simultaneous BCAS.
If prolonged hypotension occurs after surgery, the risk of stroke or myocardial infarction increases,22,24,27 so strict blood pressure management using a vasopressor is required.8,9,18,23,28 Sometimes, it is necessary to administer a vasopressor for a long time after surgery, e.g., such treatment was required for up to 30 h after unilateral CAS in previous studies.21–23 On the other hand, Lee et al. administered a vasopressor for two to seven days for prolonged hypotension after simultaneous BCAS.28 It might result in longer periods of postoperative hypotension than unilateral CAS. In our study, the period of prolonged postoperative hypotension after simultaneous BCAS was not longer than that of staged BCAS. It is necessary to investigate prolonged postoperative hypotension by increasing the number of cases, and careful attention is required to postoperative hypotension after BCAS even in case of staged as well as simultaneous procedures.
Bijuklic et al. reported that high-intensity lesions were found on DWI after CAS combined with cerebral embolic protection in 32.8% of patients.29 Altinbas et al. reported that in patients treated with CAS, perioperative HD was associated with new high-intensity lesions > 3 times higher number of new high-intensity lesions on DWI compared with that seen in patients without periprocedural HD and suggests that by preventing HD not to decrease intracranial blood flow during the perioperative period it is possible to reduce the frequency of high-intensity lesions on DWI.30 In previous studies, hypoperfusion was demonstrated to increase the risk of brain infarctions from emboli by impairing the washout of emboli from the brain circulation.31 In our study, the multiple DWI high spots after surgery tended to be occurred higher in simultaneous BCAS than in stage BCAS. In simultaneous BCAS, it is natural that the incidence of DWI high-intensity signal is higher than staged BCAS because it was performed in one procedure. Keeping the intraoperative blood pressure at higher level than staged BCAS may reduce the high-intensity lesions on DWI and prevent ischemic complications in simultaneous BCAS.
When performing BCAS, it is necessary to consider which lesion should be treated first. We initially treated the symptomatic side in symptomatic patients and the side that exhibited higher degree of stenosis in asymptomatic patients. In patients with symptomatic lesions with moderate stenosis and asymptomatic lesions with severe stenosis that are treated with staged BCAS, if hypotension occurs after the procedure on the symptomatic side there is a danger of an ischemic stroke occurring on the contralateral asymptomatic side with severe stenosis during the waiting period. No cerebral infarctions occurred during the waiting period in our staged BCAS cases, but when performing BCAS in a patient with severe stenosis on the contralateral side, simultaneous BCAS is also an option under intraoperative postoperative blood pressure management and embolic protection measures.
The present study had some limitations. First, since it was retrospective study involving a very small number of patients, it is necessary to increase the number of cases, randomize it, and investigate in a prospective study. Second, there were no cases of HPS in this study judged by clinical symptoms. It will also be necessary to investigate the frequency of HPS after simultaneous BCAS by increasing the number of cases to confirm the utility of simultaneous BCAS.
Conclusion
The safety of simultaneous BCAS may not be inferior to that of staged BCAS, and the duration of the postoperative hospital stays was almost the same after simultaneous and staged BCAS in our hospital. Therefore, in terms of the duration of total hospital stays required for BCAS, simultaneous BCAS can be superior to staged BCAS for patients with bilateral carotid artery stenosis.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
References
- 1.Brott TG, Halperin JL, Abbara S, et al. American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines; American Stroke Assocation; American Association of Neuroscience Nurses; American Association of Neurological Surgeons; American College of Radiology; American Society of Neuroradiology; Congress of Neurolgocial 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; Society for Vascular Surgery; American Academy of Neurology and Society of Cardiovascular Computed Tomography. 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. Stroke 2011; 42: e464–540.21282493 [Google Scholar]
- 2.Roger VL, Go AS, Lloyd-Jones DM, et al. American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics – 2012 update: a report from the American Heart Association. Circulation 2012; 125: e2–e220. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Yadav JS, Wholey MH, Kuntz RE, et al. Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy Investigators. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med 2004; 351: 1493–1501. [DOI] [PubMed] [Google Scholar]
- 4.Brott TG, Hobson RW, 2nd, Howard G, et al. CREST Investigators. Stenting versus endarterectomy for treatment of carotid-artery stenosis. N Engl J Med 2010; 363: 11–23. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Dumont TM, Rughani AI. National trends in carotid artery revascularization surgery. J Neurosurg 2012; 116: 1251–1257. [DOI] [PubMed] [Google Scholar]
- 6.Dimakakos PB, Kotsis TE, Tsiligiris B, et al. Comparative results of staged and simultaneous bilateral carotid endarterectomy: a clinical study and surgical treatment. Cardiovasc Surg 2000; 8: 10–17. [DOI] [PubMed] [Google Scholar]
- 7.Farsak B, Oç M, Boke E. Simultaneous bilateral carotid endarterectomy: our first experience. Ann Thorac Cardiovasc Surg 2001; 7: 292–296. [PubMed] [Google Scholar]
- 8.Liu S, Jung JH, Kim SM, et al. Simultaneous bilateral carotid stenting in high-risk patients. AJNR Am J Neuroradiol 2010; 31: 1113–1117. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Li Y, Sun W, Yin Q, et al. Safety and efficacy of simultaneous bilateral carotid angioplasty and stenting. J Thromb Thrombolysis 2014; 37: 202–209. [DOI] [PubMed] [Google Scholar]
- 10.Hokari M, Isobe M, Asano T, et al. Treatment strategy for bilateral carotid stenosis: 2 cases of carotid endarterectomy for the symptomatic side followed by carotid stenting. J Stroke Cerebrovasc Dis 2014; 23: 2851–2856. [DOI] [PubMed] [Google Scholar]
- 11.Kavaklı AS, Ayoğlu RU, Öztürk NK, et al. Simultaneous bilateral carotid endarterectomy under cervical plexus blockade. Turk J Anaesthesiol Reanim 2015; 43: 367–370. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Liu B, Wei W, Wang Y, et al. Treatment strategy for bilateral severe carotid artery stenosis: one center's experience. World Neurosurg 2015; 84: 820–825. [DOI] [PubMed] [Google Scholar]
- 13.Qureshi AI, Luft AR, Sharma M, et al. Frequency and determinants of postprocedural hemodynamic instability after carotid angioplasty and stenting. Stroke 1999; 30: 2086–2093. [DOI] [PubMed] [Google Scholar]
- 14.Sakamoto S, Kiura Y, Okazaki T, et al. Usefulness of dual protection combined with blood aspiration for distal embolic protection during carotid artery stenting. Acta Neurochir (Wien) 2015; 157: 371–377. [DOI] [PubMed] [Google Scholar]
- 15.Sakamoto S, Kiura Y, Okazaki T, et al. Carotid artery stenting for vulnerable plaques on MR angiography and ultrasonography: utility of dual protection and blood aspiration method. J Neurointerv Surg 2016; 8: 1011–1015. [DOI] [PubMed] [Google Scholar]
- 16.Abou-Chebl A, Yadav JS, Reginelli JP, et al. Intracranial hemorrhage and hyperperfusion syndrome following carotid artery stenting: risk factors, prevention, and treatment. J Am Coll Cardiol 2004; 43: 1596–1601. [DOI] [PubMed] [Google Scholar]
- 17.Roubin GS, New G, Iyer SS, et al. Immediate and late clinical outcomes of carotid artery stenting in patients with symptomatic and asymptomatic carotid artery stenosis: a 5-year prospective analysis. Circulation 2001; 103: 532–537. [DOI] [PubMed] [Google Scholar]
- 18.Henry M, Gopalakrishnan L, Rajagopal S, et al. Bilateral carotid angioplasty and stenting. Catheter Cardiovasc Interv 2005; 64: 275–282. [DOI] [PubMed] [Google Scholar]
- 19.Diehm N, Katzen BT, Iyer SS, et al. BEACH investigators. Staged bilateral carotid stenting, an effective strategy in high-risk patients – insights from a prospective multicenter trial. J Vasc Surg 2008; 47: 1227–1234. [DOI] [PubMed] [Google Scholar]
- 20.Chen MS, Bhatt DL, Mukherjee D, et al. Feasibility of simultaneous bilateral carotid artery stenting. Catheter Cardiovasc Interv 2004; 61: 437–442. [DOI] [PubMed] [Google Scholar]
- 21.Leisch F, Kerschner K, Hofmann R, et al. Carotid sinus reactions during carotid artery stenting: predictors, incidence, and influence on clinical outcome. Catheter Cardiovasc Interv 2003; 58: 516–523. [DOI] [PubMed] [Google Scholar]
- 22.Gupta R, Abou-Chebl A, Bajzer CT, et al. and consequences of hemodynamic depression after carotid artery stenting. J Am Coll Cardiol 2006; 47: 1538–1543. [DOI] [PubMed] [Google Scholar]
- 23.Ishii D, Sakamoto S, Okazaki T, et al. Overlapped stenting is associated with postoperative hypotension after carotid artery stenting. Stroke Cerebrovasc Dis 2018; 27: 653–659. [DOI] [PubMed] [Google Scholar]
- 24.Dangas G, Laird JR, Jr, Satler LF, et al. Postprocedural hypotension after carotid artery stent placement: predictors and short- and long-term clinical outcomes. Radiology 2000; 215: 677–683. [DOI] [PubMed] [Google Scholar]
- 25.Csobay-Novák C, Bárány T, Zima E, et al. Role of stent selection in the incidence of persisting hemodynamic depression after carotid artery stenting. J Endovasc Ther 2015; 22: 122–129. [DOI] [PubMed] [Google Scholar]
- 26.Lavoie P, Rutledge J, Dawoud MA, et al. Predictors and timing of hypotension and bradycardia after carotid artery stenting. AJNR Am J Neuroradiol 2008; 29: 1942–1947. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Lin PH, Zhou W, Kougias P, et al. Factors associated with hypotension and bradycardia after carotid angioplasty and stenting. J Vasc Surg 2007; 46: 846–853. discussion 853–854. [DOI] [PubMed] [Google Scholar]
- 28.Lee YH, Kim TK, Suh SI, et al. Simultaneous bilateral carotid stenting under the circumstance of neuroprotection device. A retrospective analysis. Interv Neuroradiol 2006; 12: 141–148. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Bijuklic K, Wandler A, Varnakov Y, et al. Risk factors for cerebral embolization after carotid artery stenting with embolic protection: a diffusion-weighted magnetic resonance imaging study in 837 consecutive patients. Circ Cardiovasc Interv 2013; 6: 311–316. [DOI] [PubMed] [Google Scholar]
- 30.Altinbas A, Algra A, Bonati LH, et al. ICSS Investigators. Periprocedural hemodynamic depression is associated with a higher number of new ischemic brain lesions after stenting in the International Carotid Stenting Study-MRI Substudy. Stroke 2014; 45: 146–151. [DOI] [PubMed] [Google Scholar]
- 31.Caplan LR, Hennerici M. Impaired clearance of emboli (washout) is an important link between hypoperfusion, embolism, and ischemic stroke. Arch Neurol 1998; 55: 1475–1482. [DOI] [PubMed] [Google Scholar]