Effect of carotid artery stenting on the external carotid artery

Jaw claudication and branch perfusion reduction as rare complications of fenestrated thoracic endovascular aortic repair

We report a rare case of jaw claudication following fenestrated thoracic endovascular aortic repair for a saccular aortic arch aneurysm. The brachiocephalic artery (BCA) was preserved with fenestration and intentionally half covered. Although discharged without any complications 2 weeks after the procedure, the patient subsequently experienced right mandibular fatigue at mealtime and hypotension in the right upper extremity. Angiography revealed a flap-like structure in the BCA orifice, with a 100-mm Hg pressure gradient between the aorta and BCA. Intravascular ultrasound revealed a stenosed BCA with a cord-like structure, which was considered a graft protrusion. Bare metal stenting was performed, which promptly resolved the symptoms.

Jaw Claudication Caused by Atherothrombotic External Carotid Artery Occlusion: A Case Report

Jaw claudication is a common symptom of giant cell arteritis (GCA), although atherothrombotic external carotid artery (ECA) occlusion is also known to cause jaw claudication. The patient was a 75-year-old male who experienced severe right jaw pain while chewing solid food. Magnetic resonance (MR) angiography showed right ECA occlusion. Based on laboratory tests and contrast-enhanced computed tomography (CT) angiography, atherothrombosis, not GCA, was suspected to be the cause of jaw claudication. Following conservative therapy with cilostazol, the pain was gradually alleviated in two months, and subsequent MR angiography after four months showed blood flow in the stenosed right ECA. The symptom completely disappeared in six months. Based on a previous report, we expected that jaw claudication will be ameliorated due to the development of collateral supply; however, spontaneous ECA recanalization caused improvement of symptoms in this case.

Hemodynamic Impact of Stenting on Carotid Bifurcation: A Potential Role of the Stented Segment and External Carotid Artery

Carotid stenting near the bifurcation carina is associated with adverse events, especially in-stent restenosis, thrombosis, and side branch occlusion in clinical data. This study is aimed at determining the potential biomechanical mechanisms for these adverse events after carotid stenting. The patient-specific carotid models were constructed with different stenting scenarios to study the flow distribution and hemodynamic parameters, such as wall shear stress (WSS), flow velocity, relative residence time (RRT), and oscillating shear index (OSI) in the carotid bifurcation. The results suggested that the existing stents surely reduced blood flow to the external carotid artery (ECA) but enhanced local flow disturbance both in ECA and stented internal carotid artery (ICA), and the inner posterior wall of the stented ICA and the outer posterior wall of ECA might endure a relatively low level of WSS and remarkably elevated OSI and RRT. In addition, the implanted stent leads to more ECA adverse flow than ICA after stenting. While disturbed flow near the strut increased as stent length increased, blood flow and areas of local flow disturbance in ECA slightly decreased as stent length increased. In conclusion, the results revealed that ECA might be in relatively high levels of abnormal local hemodynamics after stenting, followed by stented ICA, leading to potential adverse events after intervention.

Thirty-Day Results of the Novel CGuard-Covered Stent in Patients Undergoing Carotid Artery Stenting

OBJECTIVE

The aim of this study was to provide early-term evaluation, safety, and efficacy of the novel CGuard (Inspire MD, Tel Aviv, Israel) micromesh self-expanding stent with embolic protection system (EPS) during carotid artery stenting (CAS) procedure.

MATERIALS AND METHODS

All patients who underwent CAS with CGuard carotid stent system from January 2018 to September 2020 in a tertiary center were prospectively evaluated. Primary endpoints included technical success and perioperative neurological events (0-48 hours). Secondary endpoint was the rate of neurologic, cardiac events, and death (major adverse event or MAE) at 30 days. Patency of CGuard, peak systolic velocity (PSV), and end diastolic velocity (EDV) were evaluated at 30 days with duplex ultrasound.

RESULTS

A total of 103 patients underwent CAS procedure. Forty patients were symptomatic, and 63 patients were asymptomatic with stenosis greater than 70%. Technical success was 100%. Local anesthesia was applied in 94 patients (93%). Embolic protection devices were used in 6 patients (5.8%). Access site complications were 1.9%. Mean internal carotid artery stenosis diameter reduced from 79.47% to 14.68%. Two patients had transient ischemic attack (1.9%) and 1 patient experienced a cerebral hyperperfusion syndrome (CHS) perioperatively. External carotid artery (ECA) occlusion occurred in 1.9%. Four patients experienced jaw claudication (3.8%) postoperatively. Mean time of operation was 41 minutes. Mean duration of hospitalization was 3.1 days. The 30-day rate of MAE was 0%. CGuard patency was 100%, mean internal carotid PSV was reduced from 251.57 to 77.29 cm/s, and mean internal carotid EDV was reduced from 154.62 to 24.63 cm/s at 30 days.

CONCLUSION

Our study shows that CGuard stent with EPS is an effective and safe device for treatment of carotid artery stenosis with acceptable low perioperative neurologic events, even with low embolic protection device usage. Larger multicenter and randomized studies are necessary to confirm its long-term efficacy.

T-Configuration Stent Placement for Carotid Bifurcation Stenosis Co-Existing with Ipsilateral Intracranial Stenosis: A Case Report and Literature Review

In patients with carotid bifurcation stenosis co-existing with ipsilateral intracranial artery stenosis, combined treatment with carotid artery stenting (CAS)/carotid endarterectomy (CEA) and extracranial-to- intracranial (EC-IC) bypass can be a useful option to prevent future ischemic stroke events. EC-IC bypass requires a sufficient antegrade flow in the ipsilateral external carotid artery. However, standard CAS/CEA occasionally lead to external carotid artery occlusion. Herein, we present a case of successful one-stage endovascular revascularization of both the antegrade internal and external carotid artery flow using the carotid T-stent technique for carotid bifurcation stenosis co-existing with ipsilateral middle cerebral artery stenosis.

A Permanent Common Carotid Filter for Stroke Prevention in Atrial Fibrillation: Ex Vivo and In Vivo Pre-Clinical Testing

BACKGROUND AND PURPOSE

A novel, permanent, bilateral, common carotid artery (CCA) coil filter implant was designed to capture stroke-producing emboli in atrial fibrillation patients. Under ultrasound guidance, it is automatically deployed through a 24-guage needle and is retrievable up to 4 h post-procedure. We assessed the feasibility, safety, and effectiveness of the CCA filter in pre-clinical testing.

METHODS

In a pulsatile flow simulator, the filter's embolic capture efficiency and integrity of simulated (1.2 mm diameter nylon balls) and actual thromboemboli were tested. Implant insertion, retrieval, and chronic safety were tested in sheep by ultrasound and X-ray. At termination, the CCAs were explanted and examined by pathology, histopathology and scanning electron microscopy. The fate of captured emboli was evaluated in sheep 3 weeks after upstream injection of autologous thromboemboli.

RESULTS

In the flow simulator, 10 filters captured 29 of 29 (100%) 1.2 mm diameter nylon balls. In the thromboemboli integrity test, all captured thromboemboli (99 of 99) were adherent to the filter, without fragmentation. All sheep (n = 30/60 implants) underwent successful CCA filter implantation. During follow-ups at 4, 12, 13, 23, and 31 weeks (6 sheep/12 implants at each follow-up), there were no (0%) major bleeds, CCA damage/stenosis, implant migration, flow obstruction, or thrombi detected by ultrasound. Two organized microthrombi (<100 μm) were observed by histopathology at the puncture site. After 3 weeks, autologous captured thromboemboli (n = 10) either completely regressed (5 of 5) or did not progress (5 of 5).

CONCLUSION

These favorable pre-clinical results prompt clinical testing of the CCA filter in stroke prevention clinical trials.

Stent-induced flow disturbances in the ipsilateral external carotid artery following internal carotid artery stenting: a temporary cause of jaw claudication

Background

We hypothesize that stenting of the internal carotid artery can immediately impede blood flow to the external carotid artery by either plaque shift or stent coverage of the ostium, and thereby cause ischemic symptoms like ipsilateral jaw claudication.

Methods

Thirty-three patients with high-grade asymptomatic stenosis of the internal carotid artery who underwent endovascular treatment were examined by ultrasound of the external carotid artery and performed an exercise test by chewing chewing gum synchronously to an electronic metronome for 3 min. Tests were performed before, the day after, and 1 week after the stenting procedure. Claudication time was defined as the timespan until occurrence of pain of the masseter muscle and/or chewing dyssynchrony to the metronome for more than 15 s. Ten patients with an isolated, atherosclerotic stenosis of the external carotid artery served as controls.

Results

A significantly reduced claudication time (in seconds) was recorded in patients who underwent carotid artery stenting compared to baseline values; median 89 (interquartile range, IQR, 57 to 124) vs. median 180 (IQR 153 to 180; p < 0.001). By categorization of the flow velocity at the external carotid artery into faster or slower as 200 cm/sec, the effect was even accentuated. Stenting values showed improvement 1 week after but did not return to baseline levels. No respective changes were found in controls.

Conclusion

Stenting of the internal carotid artery lead to ipsilateral flow deterioration at the external carotid artery resulting in temporary jaw claudication. This impairment attenuated over the time and was significantly reduced after 1 week.

Acute hemifacial ischemia as a late complication of carotid stenting

Concerns about carotid artery stenting (CAS) center primarily on procedural complications like acute occlusion, stroke, and long-term intrastent restenosis. External carotid artery (ECA) thrombosis is observed during CAS follow-up, but it often remains asymptomatic or, at worst, results in jaw claudication. We report here a case of late occlusion of the ECA after CAS with symptoms of acute homolateral facial ischemia as well as pain, cyanosis, tongue numbness, and skin coldness. The patient was submitted to local thrombolysis and balloon angioplasty with regression of symptoms after recanalization. With this report, we add a caveat about blockage of the ECA ostium during CAS.

External carotid artery stenosis after internal and common carotid stenting

BACKGROUND

The external carotid artery (ECA) can be an important collateral for cerebral perfusion in the presence of severe internal carotid artery (ICA) disease. ICA stenting that covers the ECA origin may put the ECA at increased risk of stenosis. Our objective was to determine the rate of ECA stenosis secondary to ICA stenting, determine predictive factors, and describe any subsequent associated symptoms.

METHODS

We retrospectively reviewed clinical data on all ICA stents crossing the origin of the ECA placed by vascular surgeons at our institution. We analyzed patient demographics, comorbidities, stent type and sizes, as well as medication profile to determine predictors of ECA stenosis.

RESULTS

Between 2005 and 2013, there were 72 (out of 119 total ICA stenting) patients (mean age 71, 68% male) who underwent placement of ICA stents that also crossed the origin of the ECA. Six patients (8.3%) had a significantly increased ECA stenosis postprocedure. There were no occlusions. All patients with ECA stenosis maintained patency of their ICA stent and were asymptomatic. Age, gender, comorbidities, stent type and size, and medication profile were not associated with ECA stenosis after stenting.

CONCLUSIONS

ECA stenosis after ICA stenting covering the ECA origin is uncommon and not clinically significant in patients with patent ICA stents. The clinical significance of concurrent ECA and ICA stenosis after stenting is unclear as it is not captured here. The potential for ECA stenosis should not deter stenting across the ECA origin if necessary. Patient and stent factors are not predictive of ECA stenosis.

Effect of internal carotid artery stenting on superior thyroid artery Doppler flow

OBJECTIVES

Patients with carotid disease are frequently referred for carotid artery stenting based on the results of carotid duplex studies. During carotid artery stenting, the stent is usually extended into the common carotid artery, thereby crossing the external carotid artery. Previous studies have shown conflicting results regarding internal carotid stenting and external carotid artery flow velocities, but the effect of stenting on ipsilateral superior thyroid artery velocities has not been defined. This study examined the effect of internal carotid angioplasty and stenting on the ipsilateral superior thyroid artery Doppler-derived flow parameters.

METHODS

We prospectively studied preinterventional and postinterventional duplex scans obtained from 41 patients (mean age ± SD, 64 ± 10 years) who underwent carotid artery stenting. The Doppler-defined preprocedural peak systolic velocity (PSV) end-diastolic velocity (EDV), resistive index (RI), and pulsatility index (PI) in the ipsilateral external carotid and superior thyroid arteries were compared with postprocedural values.

RESULTS

Among patients with stenting, the preprocedural PSV, EDV, RI, and PI in the ipsilateral superior thyroid artery were 30 ± 11 cm/s, 13 ± 6 cm/s, 0.62 ± 0.11, and 1.04 ± 0.28,respectively; after stenting, they were 36 ± 8 cm/s, 14 ± 9 cm/s, 0.71 ± 0.07, and 1.11 ± 0.19. The preprocedural PSV, EDV, RI, and PI in the ipsilateral external carotid artery were 79 ± 24 cm/s, 17 ± 7 cm/s, 0.77 ± 0.26, and 1.27 ± 0.22; after stenting, they were 94 ± 31 cm/s, 20 ± 6 cm/s, 0.80 ± 0.4, and 1.25 ± 0.31. Despite a slight increase in superior thyroid and external carotid artery flow, there was no statistically significant change from before to after stenting.

CONCLUSIONS

This study showed no differences in blood velocity profiles in the ipsilateral superior thyroid and external carotid arteries after stenting.

Jaw claudication in the era of carotid stenting

Jaw claudication could result from external carotid artery (ECA) occlusive disease. Carotid artery stenting (CAS) has been shown to worsen the disease in the ECA. This could potentially worsen the symptoms in patients with pre-existing jaw claudication undergoing CAS. Meanwhile, ECA endarterectomy is routinely done during internal carotid artery endarterectomy (CEA). This has been shown to alleviate jaw claudication symptoms. We report a case of a high-risk patient for CEA who presented with symptomatic carotid disease as well as bilateral jaw claudication. Both symptoms resolved after CEA. We also present the case of another patient treated for recurrent high-grade carotid disease with CAS resulting in acute ECA occlusion and jaw claudication. High-risk patients with symptomatic carotid disease and jaw claudication should be considered for CEA and not only CAS.

Fate of the external carotid artery following carotid interventions

OBJECTIVE

The external carotid artery (ECA) is an important collateral pathway for cerebral blood flow. Carotid artery stenting (CAS) typically crosses the ECA, while carotid endarterectomy (CEA) includes deliberate ECA plaque removal. The purpose of the present study was to compare the long-term patency of the ECA following CAS and CEA as determined by carotid duplex ultrasound.

METHODS

Duplex ultrasounds and hospital records were reviewed for consecutive patients undergoing CAS between February 2002 and April 2008, and were compared with those undergoing CEA in the same time period. Preoperative and postoperative ECA peak systolic velocities were normalized to the common carotid artery (CCA) as ECA/CCA ratios. A significant (80% or greater) ECA stenosis was defined as an ECA/CCA ratio of 4.0. A change of ratio by more than 1 was defined as significant. Data were analyzed using Student's t test and χ(2) analysis.

RESULTS

A total of 86 CAS procedures in 83 patients were performed (81 men, mean age 69.9 years). Among them, 38.4% of patients had previous CEA, 9.6% of whom had contralateral internal carotid artery occlusion. Sixty-seven CAS and 65 CEA patients with complete duplex data in the same time period were included in the analyses. There was no difference in the incidence of severe ECA stenosis on preoperative ultrasound evaluations. During a mean follow-up of 34 months (range four to 78 months), three postprocedure ECA occlusions were found in the CAS group. The likelihood of severe stenosis or occlusion following CAS was 28.3%, compared with 11% following CEA (P<0.025). However, 62% of CEA patients and 57% of CAS patients had no significant change in ECA status. Reduction in the patient's degree of ECA stenosis was observed in 9.4% of CAS versus 26.6% of CEA patients. Overall, immediate postoperative ratios of both groups were slightly improved, but there was a trend of more disease progression in the CAS group during follow-up.

CONCLUSION

CAS is associated with a higher incidence of post-procedure ECA stenosis. Despite the absence of neurological symptoms, a trend toward late disease progression of ECA following CAS warrants long-term evaluation.

MR angiography at 3 T for assessment of the external carotid artery system

OBJECTIVE

A number of clinical situations exist in which high-resolution depiction of the external carotid artery system is required, a task not previously addressed by MR angiography. The purpose of this study was to evaluate the extent to which high-spatial-resolution MR angiography at 3 T can be used to map the normal external carotid artery system.

SUBJECTS AND METHODS

Twenty-three consenting adult patients were prospectively evaluated. Images acquired were evaluated by two independent observers, and each branch vessel was scored with regard to image quality, presence and grade of stenoses, and artifacts. Interobserver agreement regarding image quality and the presence and degree of stenosis was tested using the kappa coefficient. Differences in quality ratings between the two observers were assessed using the paired Student's t test.

RESULTS

Of 828 vessels analyzed, 92.63% were designated of diagnostic quality with no significant difference between the observers' image quality scores (p = 0.63). Good agreement was determined regarding image quality achieved (kappa = 0.716). All examinations were free of artifact sufficient to interfere with confident interpretation. Excellent correlation was seen with regard to stenosis detection and grading (kappa = 0.857). Of the external carotid artery systems assessed, 82.6% showed conventional anatomic vascular branching.

CONCLUSION

High-spatial-resolution, 3D contrast-enhanced MR angiography at 3 T using sagittal source data acquisition and an advanced acceleration factor of 6 allows high-quality (92.63% of arterial segments) visualization of the external carotid artery system, with complete head and neck vascular coverage.

Experience of 500 cases of neurophysiological monitoring in carotid endarterectomy

BACKGROUND

Experience with Intraoperative monitoring using neurophysiological and haemodynamic indices in 500 operations for carotid endarterectomy is reported.

METHODS

Transcranial Doppler technique (TCD), electroencephalogram (EEG) and bilateral median somatosensory evoked potentials (SEP) were performed. Latency and amplitude of SEP, spectral analysis of EEG signal and blood flow velocity in the medial cerebral artery (MCA) were continuously measured.

FINDINGS

After two consecutive drops of N20/P25 complex of more than 50%, a warning was given, and when the decrease continued, an the alarm raised. Abnormal EEG changes, if any, appeared after a significant decrease in the N20/P25 amplitude. A mean blood flow velocity drop below 40% of the reference value after cross clamping was rated as a significant warning event.A warning as a result of a decrease in N20/P25 amplitude occurred in 80 operations (16.0%), after an spectral edge frequency decrease in 2 cases (0.4%) and after a V(mean) decrease in 21 cases (4.2%). False negative results were experienced in 2 patients (0.4%). A shunt was inserted in 2.8% of the operations. The overall mortality/morbidity rate was 2.4%.

CONCLUSION

A decrease of more than 50% in the amplitude of the thalamocortical somatosensory evoked potential complex N20/P25 proved to be the most reliable warning of danger of ischaemia during carotid endarterectomy.

The Fate of the External Carotid Artery after Carotid Artery Stenting. A Follow-up Study with Duplex Ultrasonography

OBJECTIVE

To evaluate the long-term effect of carotid angioplasty and stenting (CAS) of the internal carotid artery (ICA) on the ipsilateral external carotid artery (ECA).

SUBJECTS AND METHODS

We prospectively registered the pre- and post-interventional duplex scans obtained from 312 patients (mean age 70 years) who underwent CAS. Duplex scans were scheduled the day before CAS, 3 and 12 months post-procedurally and yearly thereafter, to study progression of obstructive disease in the ipsilateral ECA compared to the contralateral ECA. The duplex ultrasound criteria used to identify ECA stenosis >or=50% were Peak Systolic Velocities of >or=125 cm/s.

RESULTS

Preprocedural evaluation of the ipsilateral ECA demonstrated >or=50% stenosis in 32.7% of cases vs 30% contralateral. Both ipsilateral and contralateral 3 (1%) ECA occlusions were noted. After stenting 5 (1.8%) occlusions were seen vs 1% contralateral. No additional ipsilateral occlusions and 2 additional contralateral occlusions were noted at extended follow-up. The prevalence of >or=50% stenosis of the ipsilateral ECA (Kaplan-Meier estimates) progressed from 49.1% at 3, to 56.4%, 64.7%, 78.2%, 72.3%, and 74% at 12, 24, 36, 48, and 60 months respectively. Contralateral prevalences were 31.3%, 37.7%, 41.7%, 43.1%, 46.0%, and 47.2% respectively (p<0.001). Progression of stenosis was more pronounced in 234 patients (75%) with overstenting of the carotid bifurcation (p=0.004).

CONCLUSION

Our results show that significant progression of >or=50% stenosis in the ipsilateral ECA occurs after CAS. There was greater progression of disease in the ipsilateral compared with the contralateral ECA. Progression of disease in the ECA did not lead to the occurrence of occlusion during follow up.

Differential effects of carotid artery stenting versus carotid endarterectomy on external carotid artery patency

PURPOSE

To determine the effect of stent coverage of the external carotid artery (ECA) after carotid artery stenting (CAS) compared to eversion endarterectomy of the ECA after carotid endarterectomy (CEA).

METHODS

The records of 101 CAS and 165 CEA procedures performed over 2 years were reviewed. Duplex velocities and history and physical examinations were taken prior to the procedure, at 1 month, and at 6-month intervals subsequently. CAS was performed by extending the stent across the internal carotid artery (ICA) lesion into the common carotid artery (CCA) thereby covering the ECA. CEA was performed with eversion endarterectomy of the ECA.

RESULTS

The mean peak systolic velocities (PSV) in the ICA pre-CAS and pre-CEA were 361 and 352 cm/s, respectively. In terms of CAS, there was a significant increase in ECA velocities versus baseline at 12 (p = 0.009), 18 (p = 0.00001), and 24 (p = 0.005) months. In the CEA group, there was a significant decrease in ECA velocities versus baseline at 1 (p = 0.01) and 6 (p = 0.004) months. There were 2 occluded ECAs in follow-up in the CAS group and none in the CEA group. No significant differences were noted when comparing preprocedural ICA or ECA velocities. However, at the 1-, 6-, and 12-month intervals, the ECA velocities in the CAS group were significantly higher than in the CEA group (p = 0.03, p = 0.001, and p = 0.0004, respectively). There were no neurological symptoms in any patients during the study period.

CONCLUSION

Although progressive stenosis of the ECA is noted during CAS, the ECA usually does not occlude. Furthermore, there are no associated neurological symptoms. Thus, apprehension for progressive ECA occlusion should not be a contraindication to CAS. In addition, concern for ECA coverage should not deter stent extension from the ICA to the CCA during CAS.