Histological analysis of extracranial carotid artery aneurysms

A technique for reconstruction of a giant extracranial internal carotid artery aneurysm: A technical note

Background

Surgery is effective for extracranial internal carotid artery (EICA) aneurysms. However, the risk of cranial nerve injury associated with surgical repair, such as graft-assisted resection and extracranial-intracranial bypass techniques, is relatively high. Here, we report two cases of surgical treatment for EICA aneurysms and describe the surgical techniques and strategies to avoid cranial nerve injury.

Methods

Two patients presented to our facility with an increasing cervical pulsatile mass and no neurological symptoms. Angiography showed a large aneurysm in the cervical internal carotid artery. Surgical treatment was performed to prevent rupture of the aneurysm. In both patients, the aneurysm was strongly attached to the vagus nerve. The aneurysm and vagus nerve were carefully dissected using a low-power bipolar (20 Malis; 3 watts), leaving connective tissue on the vagus nerve side.

Results

The aneurysm was detached from the vagus nerve without injury. Based on intraoperative findings, one patient underwent clipping, and the other underwent aneurysmectomy and primary closure for aneurysm obliteration and angioplasty. Both patients were discharged without any cranial nerve dysfunction.

Conclusion

The selection of a strategy based on intraoperative findings and low-power bipolar cutting is important for the treatment of extracranial carotid artery aneurysms to preserve cranial nerves.

Surgical management of extracranial internal carotid artery aneurysm-Case report and literature review

Key Clinical Message

Extracranial internal carotid artery aneurysms (EICAAs) can lead to serious medical conditions, such as stroke or compression over cranial nerves. In very few cases, there may be hemorrhagic complications due to the rupture. Although rare, they should be suspected cause in every patient with transitory ischemic attack or stroke, especially in the presence of pain, palpable mass or bruit in the neck.

Abstract

Extracranial internal carotid artery aneurysms (EICAAs) are rare arterial aneurysms, with a prevalence of less than 1%. Although they are not common, these aneurysms can lead to serious medical conditions, such as stroke or compression over cranial nerves. In very few cases, there may be hemorrhagic complications due to the rupture of the aneurysm. This report presents a case of a successful surgical intervention for EICAA, and an overview of symptoms, risk factors, causes, diagnostic procedures, treatments, and potential postoperative complications. A 70-year-old Albanian lady had been experiencing pain due to a pulsating mass in her neck for many years. Physical examination did not reveal any signs of infection, injury, or previous surgery. A palpable thrill and a carotid bruit were detected over an evident pulsating mass on the left side of her neck. Her past medical history was consistent with three transitory ischemic attacks in recent months and a stroke 5 years earlier. Comorbidities included hypercholesterolemia, hypertension, and long-standing coronary artery disease. Imaging investigation in terms of ultrasound and CT-scan confirmed the presence of an aneurysm of the proximal tract of the internal carotid artery measuring 42 × 31 mm. Surgery was indicated on symptomatic and anatomical grounds. The procedure was carried out under general anesthesia. After proximal and distal clamping, the aneurysm was excised followed by end-to-end anastomosis of the internal carotid artery. The postoperative course was uneventful, and the patient was discharged home on the fifth postoperative day. Despite the growing number of reported cases of successful endovascular treatment for internal carotid artery aneurysms, open surgery remains a safe and effective treatment option. However, it is crucial to provide customized treatment plans for each patient based on their individual characteristics and the particularities of their aneurysm.

Carotid tortuosity is associated with extracranial carotid artery aneurysms

BACKGROUND

Tortuous arteries may be associated with carotid dissection. The intima disruption caused by a carotid dissection is a possible cause of extracranial carotid artery aneurysms (ECAAs). The aim was to investigate if carotid tortuosity is also associated with ECAA in patients without presence or history of a carotid artery dissection.

METHODS

A retrospective case-control study was performed including 35 unilateral ECAA patients (cases) and 105 age- and sex-matched controls. Tortuosity was expressed as tortuosity-index (TI), curvature, and torsion measured on computed tomography angiography (CTA) data in 3Mensio Vascular and MATLAB by two independent investigators. Primary comparison was tortuosity in ipsi- versus contralateral carotid artery within the cohort of ECAA patients. Secondary comparison was tortuosity with ipsilateral carotid arteries in control patients. All observations were assessed on inter- and intra-operator reproducibility.

RESULTS

Carotid tortuosity was comparable within the cohort of ECAA patients (Spearman correlation 0.76, P<0.001), yet distinctively higher in comparison with unilateral controls. After adjustment for patient characteristics, presence of ECAA was associated with TI (β 0.146, 95% CI: 0.100-0.192). All tortuosity observations showed excellent inter- and intra-operator reproducibility.

CONCLUSIONS

Carotid tortuosity seems to be a risk factor for development of ECAA. Surveillance of individuals with increased carotid tortuosity therefore potentially ensures prompt diagnosis and treatment of ECAA. However, future research should investigate if persons with an increased tortuosity do indeed develop ECAA.

Disturbed flow's impact on cellular changes indicative of vascular aneurysm initiation, expansion, and rupture: A pathological and methodological review

Aneurysms are malformations within the arterial vasculature brought on by the structural breakdown of the microarchitecture of the vessel wall, with aneurysms posing serious health risks in the event of their rupture. Blood flow within vessels is generally laminar with high, unidirectional wall shear stressors that modulate vascular endothelial cell functionality and regulate vascular smooth muscle cells. However, altered vascular geometry induced by bifurcations, significant curvature, stenosis, or clinical interventions can alter the flow, generating low stressor disturbed flow patterns. Disturbed flow is associated with altered cellular morphology, upregulated expression of proteins modulating inflammation, decreased regulation of vascular permeability, degraded extracellular matrix, and heightened cellular apoptosis. The understanding of the effects disturbed flow has on the cellular cascades which initiate aneurysms and promote their subsequent growth can further elucidate the nature of this complex pathology. This review summarizes the current knowledge about the disturbed flow and its relation to aneurysm pathology, the methods used to investigate these relations, as well as how such knowledge has impacted clinical treatment methodologies. This information can contribute to the understanding of the development, growth, and rupture of aneurysms and help develop novel research and aneurysmal treatment techniques.

Characterizing Tissue Remodeling and Mechanical Heterogeneity in Cerebral Aneurysms

Accurately assessing the complex tissue mechanics of cerebral aneurysms (CAs) is critical for elucidating how CAs grow and whether that growth will lead to rupture. The factors that have been implicated in CA progression - blood flow dynamics, immune infiltration, and extracellular matrix remodeling - all occur heterogeneously throughout the CA. Thus, it stands to reason that the mechanical properties of CAs are also spatially heterogeneous. Here, we present a new method for characterizing the mechanical heterogeneity of human CAs using generalized anisotropic inverse mechanics, which uses biaxial stretching experiments and inverse analyses to determine the local Kelvin moduli and principal alignments within the tissue. Using this approach, we find that there is significant mechanical heterogeneity within a single acquired human CA. These results were confirmed using second harmonic generation imaging of the CA's fiber architecture and a correlation was observed. This approach provides a single-step method for determining the complex heterogeneous mechanics of CAs, which has important implications for future identification of metrics that can improve accuracy in prediction risk of rupture.

Chronic fusiform extracranial vertebral artery aneurysm with recurrent posterior circulation emboli: Case report and review of the literature

We report a case of a 64-year-old man with a fusiform right extracranial vertebral artery aneurysm, spanning over half the extra-cranial V2 (foraminal) segment, presenting with recurrent multi-focal posterior circulation embolic ischaemic stroke. The patient was treated with endovascular embolisation of the right vertebral artery to prevent further thrombo-embolic events. Distal and proximal occlusion of the aneurysmal vertebral artery was performed with a micro-vascular plug with partial aneurysm sack embolisation to aid thrombosis and reduce the risk of recanalisation. Two months post procedure MR angiography confirmed successful aneurysm occlusion with no post-procedural complication. The patient returned to his normal independent life. Endovascular treatment with vessel sacrifice is an effective treatment with low morbidity and we believe the MVP device to be a efficacious option in the vertebral artery.

Clinical Analysis of Interventional Therapy for Eight Cases of Extracranial ICA Aneurysm

Objective:

To explore the interventional therapy and clinical efficacy of extracranial ICA aneurysm.

Methods:

The clinical data of eight patients with extracranial ICA aneurysm treated by interventional stent implantation from December 2014 to February 2018 in the Neurosurgery Department of the Third Hospital of Mianyang were analyzed. And this research was a retrospective analysis. All patients underwent digital subtraction angiography (DSA) and were diagnosed with extracranial carotid artery aneurysm. These patients, therefore, were treated with interventional stent implantation.

Results:

Interventional treatment was successfully conducted on all eight patients. In eight patients, the aneurysm cavity was not developed immediately after angiography, and in one case, the aneurysm cavity was developed with coil-assisted embolization. All the internal carotid arteries were well developed, with no complications such as intraoperative rupture, bleeding and thrombosis occur. Follow-up for three months to two years showed that the patients recovered well, the GOS score was 4 points for patients with cerebral infarction, and the rest reached five points. Follow-up CTA showed no signs of aneurysm recurrence or ICA restenosis.

Conclusion:

Interventional stent placement is a preferable and relatively safe method for the treatment of extracranial carotid artery aneurysm with less trauma and short operation time.

A case of idiopathic extracranial carotid artery pseudoaneurysm with a rare clinical course and pathological features

Extracranial carotid artery aneurysms (ECAAs) are rare, with the etiology mainly classified as degeneration or dissection. Pseudoaneurysms in the region are even rarer and are seen following trauma, iatrogenic injury, or infection. We report a case of extracranial carotid artery pseudoaneurysm (pseudo-ECAA) with a rare clinical course and pathological features. A 58-year-old man presented with swelling and purpura on the left side of his neck after sneezing. Radiological examinations suggested a ruptured left common carotid artery aneurysm. The operative findings were consistent with a pseudoaneurysm. Pathological examination revealed disarrangement and degeneration of smooth muscle fibers in the media, in addition to scattered foci of mucoid accumulation and irregular-shaped cavitation in the medial extracellular matrix, raising the possibility of an intrinsic dysfunction of the vascular wall in the pathological process of pseudoaneurysm formation.

Endovascular techniques in the treatment of extracranial carotid artery aneurysms

OBJECTIVE

Carotid artery aneurysms and pseudoaneurysms (extracranial carotid artery aneurysm [ECCAs]) are relatively rare. The gold standard treatment has historically been open repair; however, there is increasing evidence of successful treatment of ECCAs with endovascular techniques. Our study examines the evolving experience with endovascular management of ECCAs at a tertiary care center.

METHODS

We performed a retrospective analysis of patients with ECCAs who underwent endovascular interventions at a single institution from 2010 to 2020. With increasing experience, the techniques evolved from covered stents to stent-assisted coil embolization and finally to braided stents and overlapping closed cell stents.

RESULTS

There were 18 ECCAs in 17 patients treated with endovascular modalities. The average age was 65.9 years. There were 11 males (64.7%). Seven aneurysms (38.9%) were symptomatic: three patients had painless pulsatile masses, three patients had painful pulsatile masses, and one had transient ischemia attacks. Two (11.1%) were treated with covered stents, 2 (11.1%) were treated with stent-assisted embolization, 2 (11.1%) were treated with flow-diverting braided stents, 10 (55.6%) were treated with overlapping bare metal stents, and 2 (11.1%) were treated with embolization or ligation alone. Technical success was achieved in all patients. The mean duration of follow up was 338 days (range, 8-3039 days). No perioperative or postoperative complications were encountered, including no neurologic deficits and no embolic events. All patients were discharged on postoperative day 1 or 2. All 16 stents (100%) retained vessel patency on follow-up imaging and exclusion of ECCAs was confirmed on postprocedure surveillance imaging.

CONCLUSIONS

Endovascular modalities for the management of ECCAs have evolved with experience. Our study suggests that endovascular management is technically feasible as well as clinically effective and suggests an algorithm for navigating the various treatment modalities.

Gadolinium Enhancement of the Aneurysm Wall in Extracranial Carotid Artery Aneurysms

BACKGROUND AND PURPOSE

The natural history and optimal treatment of extracranial carotid artery aneurysms are unknown. Gadolinium enhancement of the aneurysm wall may reflect aneurysm wall inflammation and instability. In this study, we investigated the feasibility of extracranial carotid artery aneurysm wall imaging and explored a potential relationship of aneurysm wall enhancement with aneurysm growth and the presence of (silent) brain infarcts and white matter lesions.

MATERIALS AND METHODS

Fourteen conservatively treated patients with 15 asymptomatic extracranial carotid artery aneurysms underwent gadolinium-enhanced 3T MR imaging at 2 time points with a 12-month interval. Primary outcome was growth of the aneurysm sac (≥2.0 mm); secondary outcomes were the presence of (silent) brain infarcts and white matter lesions at baseline and follow-up. MR images were reviewed by 2 independent observers, and inter- and intraobserver reproducibility was assessed.

RESULTS

Seven (50%) patients were men; the median age was 55 years (range, 40-69 years). Eleven extracranial carotid artery aneurysms (73%) were saccular (median size, 11 mm; range, 5.0-38.5 mm), and 4 were fusiform (median size, 21.5 mm; range, 10.0-40.0 mm). Eleven of 15 aneurysms (73%) exhibited gadolinium enhancement at baseline. Four aneurysms (27%) showed growth at follow-up imaging, 2 gadolinium-positive (+) and 2 gadolinium-negative (-) (P = .245). Three patients (21%) had ipsilateral brain infarcts at baseline; 1 of them showed a new silent brain infarct at follow-up imaging (gadolinium+). Nine patients (64%) showed bilateral white matter lesions at baseline. In 3 patients, increased white matter lesion severity was observed at follow-up (2 gadolinium+). All observations showed excellent inter- and intraobserver reproducibility.

CONCLUSIONS

In this explorative study, we demonstrated that extracranial carotid artery aneurysm wall imaging was feasible. Future well-powered studies are needed to investigate whether extracranial carotid artery aneurysm gadolinium enhancement predicts aneurysm growth and thromboembolic complications.

Management of Arterial Pseudoaneurysms of the Neck in a Pediatric Population: An Endovascular Case Series and Review of Literature

BACKGROUND

Arterial pseudoaneurysms of the neck are rarely reported in the pediatric population and no dedicated large series are available. Trauma and infection are the most common causes for these aneurysms, with congenital and collagen vascular disorders being the less common causes. These lesions can be life threatening, especially when they present with bleeding or airway compromise.

METHODS

We searched our radiology information system for all cases of pediatric neck aneurysm presented between June 2015 and May 2018. These cases were analyzed for clinicoepidemiologic variables, clinical presentation, imaging findings, management, and follow-up.

RESULTS

Six children were included in the study (male/female ratio, 5:1), with a mean age of 7.8 years (range, 2.5-15 years). Four presented acutely with either bleeding or rapidly enlarging neck swelling, whereas 2 presented with slowly increasing pulsatile swelling. One had a traumatic cause, 2 had infections, and 1 had infective cervical lymphadenitis complicated by iatrogenic injury whereas no definite causative mechanisms could be accounted for in 2 patients. Two of the children were managed by trapping of the aneurysm and 2 only by proximal parent vessel occlusion. The other 2 children were treated with stent graft deployment across the aneurysm neck to reconstruct the parent vessel. All the patients were doing well during the follow-up period (mean, 14.8 months).

CONCLUSIONS

Endovascular means of treatment for pediatric neck aneurysms is relatively simple and safe. Although parent vessel sacrifice is the gold-standard management, vessel-preserving strategies can be tried in select cases with favorable anatomy.

Operative managements of extracranial carotid artery aneurysms: a report of three cases and literature review

Background

The purpose of this study is to report the treatment approaches and postoperative outcomes of extracranial carotid artery aneurysms (ECAAs) and discuss the symptoms, related risk factors, etiology, diagnostic methods, treatments, and follow-up period complications.

Case presentation

We describe three patients with symptomatic extracranial carotid artery aneurysms; one of them was treated with end-to-end anastomosis of the extracranial internal carotid artery (EICA) after the resection of the aneurysm, while the other two patients were deployed with Willis covered stents in the extracranial internal carotid artery. All of the patients were in good condition when discharged home. After a mean follow-up period of 8 months, all the patients were alive and only one of them had the neurologic deficit. Additionally, we reviewed the relative literatures.

Conclusion

Both of the surgical and endovascular treatments have relatively satisfactory outcomes in ECAA patients. However, it is necessary to provide individualized treatments to different patients according to the characteristics of the aneurysms.

Comparability of semiautomatic tortuosity measurements in the carotid artery

Purpose

Increased arterial tortuosity has been suggested as a predisposing factor for carotid artery dissection, which is an important risk factor for development of extracranial carotid artery aneurysms (ECAA). Prior to comparison with non-ECAA controls, the optimal measurement technique should be defined. This study describes the difference between software packages in terms of reproducibility and absolute outcome of arterial tortuosity measurements in ECAA patients.

Methods

CT-angiography analysis was performed on 12 ECAA patients selected from our registry, using four software packages: 3mensio Vascular, TeraRecon, Vital Images, and Aycan OsiriX PRO. The tortuosity index (TI) was calculated from the skull base until the carotid bifurcation and aortic arch, and was defined as the centerline’s true length divided by the straight line distance. Intraclass correlation coefficients (ICC) with 95% confidence intervals were calculated to quantify inter- and intra-observer variability within one software package, and differences in measured TI between packages.

Results

Inter-observer agreement was nearly perfect for 3mensio, excellent for Vital Images and OsiriX, and substantial for TeraRecon, with ICC 0.99 (0.96–1.0), 0.90 (0.69–0.97), 0.84 (0.53–0.95), and 0.72 (0.28–0.91), respectively. Intra-observer agreement ranged from ICC 1.0 for 3mensio to 0.91 for TeraRecon. Agreements in TI ranged from ICC 0.99 (0.98–1.0) for 3mensio vs. OsiriX, to 0.95 (0.82–0.98) for 3mensio vs. TeraRecon. Median time needed to complete one round of measurements was highest for OsiriX (p = 0.013).

Conclusions

Carotid artery tortuosity measurements are reproducible and comparable between current commercially available software packages, with high intra-observer agreement. Although the reproducibility differed per software packages, all packages scored an acceptable inter-observer agreement.

A Rare Cause of Juvenile Stroke: Extracranial Carotid Artery Aneurysm with Venous Complete Reconstruction of the Carotid Bifurcation

Extracranial carotid artery aneurysms (ECAA) are a rare cause of embolic stroke. The underlying etiology is variable, with atherosclerosis being the most common entity in older subjects. Several treatments have been developed over the last 20 years, but the preferred method remains unknown. Notwithstanding the widespread use of endovascular techniques, surgical reconstruction by means of a bifurcated venous bypass graft should be applied in younger patients. In this way, it is possible to avoid major concerns about the development of long-term intrastent restenosis, and also to spare the external carotid artery which represents the main branch for the ipsilateral cerebral and facial perfusion. We propose ECAA resection and interposition of the inverted great saphenous vein to both the internal and external carotid artery by means the use of a tributary, i.e., the Giacomini vein.

The effects of mesenchymal stem cells on the structure and contractile force of the carotid artery in a rat aneurysm model

Background/aim: An aneurysm is a pathological enlargement of an artery characterized by the thinning of the elastic fiber layer in the tunica media. Because the aneuritic artery wall is weakened, these vessels can rupture and cause serious bleeding. Surgical methods are often used for the treatment of aneurysms. However, cell-based therapies are less invasive and potentially safer alternatives. In this study, the therapeutic efficacy of rat adipose tissue-derived mesenchymal stem cells (MSCs) was investigated in a new carotid artery aneurysm model.Materials and methods: Arteries were pretreated with elastase to create aneurysms. Gelatin matrices containing MSCs were applied to the outer surface of the elastase-treated carotid artery sections.Results: Healing of the aneuritic arteries for which MSC applications were performed was significantly better than in the aneuritic group. The histological structure of the vessels was largely reconstituted, and the contractile force of the MSC-treated group was similar to the untreated healthy group.Conclusions: Application of MSCs facilitates the healing of aneurysms. Hereby, MSC application could be a promising approach for clinical applications after further validation processes are concluded.

Prevalence of extracranial carotid artery aneurysms in patients with an intracranial aneurysm

Background and purpose

Aneurysms in various arterial beds have common risk- and genetic factors. Data on the correlation of extracranial carotid artery aneurysms (ECAA) with aneurysms in other vascular territories are lacking. We aimed to investigate the prevalence of ECAA in patients with an intracranial aneurysm (IA).

Methods

We used prospectively collected databases of consecutive patients registered at the University Medical Center Utrecht with an unruptured intracranial aneurysm (UIA) or aneurysmal Subarachnoid hemorrhage (SAH). The medical files of patients included in both databases were screened for availability of radiological reports, imaging of the brain and of the cervical carotid arteries. All available radiological images were then reviewed primarily for the presence of an ECAA and secondarily for an extradural/cavernous carotid or vertebral artery aneurysm. An ECAA was defined as a fusiform dilation ≥150% of the normal internal or common carotid artery or a saccular distention of any size.

Results

We screened 4465 patient records (SAH database n = 3416, UIA database n = 1049), of which 2931 had radiological images of the carotid arteries available. An ECAA was identified in 12/638 patients (1.9%; 95% CI 1.1–3.3) with completely imaged carotid arteries and in 15/2293 patients (0.7%; 95% CI 0.4–1.1) with partially depicted carotid arteries. Seven out of 27 patients had an additional extradural (cavernous or vertebral artery) aneurysm.

Conclusions

This comprehensive study suggests a prevalence for ECAA of approximately 2% of patients with an IA. The rarity of the disease makes screening unnecessary so far. Future registry studies should study the factors associated with IA and ECAA to estimate the prevalence of ECAA in these young patients more accurately.

Stent Graft-in-Stent Graft as a Rescue Technique for Endovascular Treatment of Giant Extracranial Internal Carotid Aneurysm

Endovascular treatment of a giant extracranial internal carotid aneurysm by a stent graft implantation was unsuccessful due to a high flow leak directly through the stent graft's coating. The problem was solved deploying a second stent graft inside the previously implanted one resulting in complete exclusion of the aneurysmal sac and patent carotid lumen preservation. The review of the literature did not provide a case using this endovascular strategy. Follow-up for more than 12 months, using CT angiography, showed confirmed aneurysmal exclusion and carotid patency and no clinical complications have been detected.