Single-stage hybrid management of severe carotid stenosis and unruptured intracranial aneurysms using direct transcarotid access: Illustrative case

Abstract

Background:

The coexistence of symptomatic extracranial internal carotid artery stenosis (ICAS) and unruptured intracranial aneurysms (UIAs) is an uncommon but clinically challenging condition for which there is no standardized treatment strategy. The optimal treatment sequence remains controversial because carotid revascularization may theoretically alter intracranial hemodynamics, whereas endovascular treatment through a critically stenotic carotid artery presents significant technical challenges. Hybrid approaches may provide an alternative for carefully selected patients.

Case Description:

A 74-year-old man with severe multilevel cervicocerebral stenosis disease characterized by complete right internal carotid artery (ICA) occlusion with posterior-to-anterior collateralization and critical left ICAS, severe left vertebral artery stenosis with collateral recruitment, and two UIAs: an anterior communicating (ACom) aneurysm and a Posterior communicating artery (PCom) wide-necked aneurysm, underwent multidisciplinary evaluation following coronary revascularization and dual antiplatelet therapy. Considering the severely compromised collateral reserve, the technical limitations of transfemoral navigation across a heavily calcified stenosis, and the potential risks associated with staged procedures, a single-stage hybrid strategy was selected. Through direct surgical exposure and puncture of the left ICA distal to the stenotic segment, the ACom aneurysm was treated with a Woven EndoBridge, and the wide-necked aneurysm with a flow diverter, followed immediately by carotid endarterectomy (CEA).

Conclusion:

This illustrative case demonstrates that individualized single-stage hybrid management using direct carotid access, endovascular aneurysm treatment, and CEA may represent a feasible option in highly selected patients when conventional staged strategies or transfemoral access are technically unfavorable. Careful multidisciplinary planning and tailored treatment sequencing are essential in these complex neurovascular scenarios.

INTRODUCTION

The coexistence of extracranial carotid stenosis (CS) and unruptured intracranial aneurysms (UIAs) has been reported in approximately 1.9–6% of patients undergoing angiographic evaluation or carotid revascularization.[15,23,28] In patients with symptomatic CS, aneurysms frequently arise along vessels involved in collateral circulation, particularly the posterior communicating (PCom) and anterior communicating (ACom) complex.[14] This association is clinically relevant because high-grade CS may alter cerebral perfusion, increase dependence on collateral pathways, and reduce cerebrovascular reserve.[2,26] Consequently, autoregulation becomes impaired, and the brain becomes highly sensitive to subsequent changes in systemic blood pressure or flow.[29]

Despite its clinical relevance, there is currently no consensus regarding the optimal treatment sequence in patients with concomitant significant CS and UIAs. Proposed strategies include carotid revascularization before aneurysm treatment, aneurysm exclusion before carotid repair, staged procedures, or simultaneous hybrid approaches.[7,12,13,16,28] Each option carries distinct technical and physiological considerations. Carotid revascularization may abruptly restore perfusion pressure to previously hypoperfused territories, which can precipitate hemorrhagic complications,[15,18,21,29] whereas endovascular aneurysm treatment through a critically stenotic carotid artery may be limited by unstable catheter support, embolic risk, and difficult navigation across heavily calcified vessels.[19,33]

We present the successful management of an exceptionally complex cerebrovascular case involving right Carotid occlusion (CO), left CS, bilateral vertebral artery stenoses, and two UIAs with posterior-to-anterior collateral recruitment toward the right middle cerebral artery territory through the PCom artery. This vascular configuration created a high-risk hemodynamic scenario in which anterior circulation perfusion depended on a fragile balance between the only patent carotid axis and compromised vertebrobasilar collateral reserve.

CASE DESCRIPTION

A 74-year-old man with a history of long-standing systemic hypertension, untreated chronic coronary artery disease, and a transient ischemic attack 1 year earlier was referred to our neurosurgery department after an incidentally identified intracranial aneurysm was identified in the setting of recent refractory acute severe headache and advanced extracranial carotid artery disease. Neurological examination revealed no focal deficits, and the patient was functionally independent (a modified Rankin Scale score of 1). Computed tomography angiography (CTA) and digital subtraction angiography (DSA) were performed to comprehensively characterize the intracranial and extracranial cerebrovascular disease. These studies demonstrated an ACom aneurysm [Figure 1a] in association with other anatomical variants, including a dominant left A1 segment with a hypoplastic contralateral A1 segment of the anterior cerebral arteries, as well as a hypoplastic left PCom artery. The DSA shows a small, broad-based, wide-necked aneurysm arising from the PCom of the left ICA [Figure 1b]. Angiographic evaluation of the supra-aortic vessels revealed complete atherosclerotic occlusion of the right ICA from its origin and severe ICAs (~95%) of the cervical left ICA [Figure 2a and 2b, respectively]. Evaluation of the posterior circulation demonstrated severe stenosis of the left vertebral artery [Figure 2c], whereas the right vertebral artery remained patent [Figure 2d]. Posterior-to-anterior collateral flow contributed to perfusion of the right ICA territory through the right PCom.

Figure 1:

a) CTA with 3D reconstruction demonstrating a dominant left A1 segment (black arrow) and a contralateral hypoplastic A1 segment (blue arrow) of the anterior cerebral artery, an ACom aneurysm (yellow arrow), and a left hypoplastic PCom artery (white arrow). b) DSA lateral view of the left ICA showing a small wide-necked PCom aneurysm (red arrow), and the ACom aneurysm (yellow arrow). CTA: Computed tomography angiography; ACom: Anterior communicating; PCom: Posterior communicating; DSA: Digital subtraction angiography; ICA: Internal carotid artery.

Figure 2:

(a) DSA of the right carotid artery demonstrating CO of the ICA. (b) DSA of the left carotid artery demonstrating severe stenosis of the cervical ICA. (c) Sagittal CTA reconstruction demonstrating severe stenosis of the left vertebral artery with collateral recruitment. (d) DSA of the right vertebral artery demonstrating preserved vertebrobasilar circulation and adequate patency.. DSA: Digital subtraction angiography; CO: Carotid oclussion; ICA: Internal carotid artery; CTA: Computed tomography angiography.

These findings limited safe endovascular navigation and raised concerns regarding cerebral hemodynamics and access feasibility. Given the lack of robust evidence on the hemodynamic effects of carotid angioplasty on UIA stability, particularly in the setting of impaired autoregulation, a multidisciplinary discussion was undertaken. Key considerations included the risk of cerebral hyperperfusion following revascularization, increased aneurysmal wall shear stress and transmural pressure, potential aneurysm destabilization or rupture, and the prohemorrhagic effects of dual antiplatelet therapy. Collectively, these factors defined a high-risk profile for conventional staged or isolated endovascular strategies. Therefore, a hybrid strategy was selected, involving open carotid access, endovascular control of the aneurysms, CEA, and immediate femoral postoperative angiographic control.

Cervical approach

The patient was positioned with the neck hyperextended and rotated approximately 30° toward the right side. A longitudinal incision was made along the anterior border of the sternocleidomastoid muscle, extending from the mandibular angle to the superior edge of the thyroid cartilage. The superficial fascia and the first layer of the deep cervical fascia were incised, allowing lateral mobilization of the sternocleidomastoid muscle to expose the carotid triangle, which is bounded by the digastric muscle superiorly, the sternocleidomastoid muscle laterally, and the omohyoid muscle medially. The carotid sheath was then opened, and the distal extent of the occlusion was determined by gentle palpation of the carotid bifurcation and confirmed using intraoperative Doppler. Once the appropriate segment distal to the stenosis was identified, a vessel loop was placed to provide mild traction on the ICA, facilitating exposure of a suitable puncture site for the endovascular team. The entire procedure was performed under intraoperative neuromonitoring, including somatosensory evoked potentials and motor evoked potentials, to detect any neurological changes suggestive of arterial compromise or artery-to-artery embolism during the dissection.

Direct transcarotid endovascular approach

After a plaque-free segment, approximately 3 cm proximal to the carotid bifurcation, was identified. Direct ICA puncture was then performed, allowing controlled vascular access with a 7-in-6 Fr short introducer sheath, which was secured to the carotid artery using a silk suture to prevent displacement. Then, a 6 Fr × 115 cm distal access catheter (Stryker Neurovascular, Fremont, California, USA) was advanced, supported by a VIA 17 microcatheter (0.017 in, MicroVention, Aliso Viejo, California, USA) and a 0.014 in × 200 cm microguidewire. Using predefined working projections, selective visualization of both aneurysms was achieved. Careful attention was given to dome orientation, neck width, and aneurysm equator. This allowed controlled and directed navigation toward both lesions while minimizing manipulation of diseased proximal vessels. Given the small size and wide neck configuration of the ACom aneurysm (3.2 × 2.1 mm), an intrasaccular flow disruption strategy was selected. A Woven EndoBridge (WEB) device (4 × 2 mm, MicroVention, Aliso Viejo, California, USA) was chosen according to the standard sizing principle (+1 mm to aneurysm width and −1 mm to aneurysm height), ensuring optimal neck coverage and device stability. The device was successfully deployed within the aneurysm sac [Figure 3a], achieving satisfactory positioning and expansion with complete neck coverage on fluoroscopic assessment [Figure 3b]. For the treatment of the left supraclinoid ICA wide-necked aneurysm, a 0.021-inch × 165 cm microcatheter was navigated over a 0.014-inch × 200 cm microwire under roadmap guidance to the target segment. Subsequently, a p64 flow diverter (FD) (4 × 18 mm, Phenox GmbH, Bochum, Germany) was deployed across the supraclinoid segment of the left ICA [Figure 4a], fully covering the aneurysm. Control angiographic runs in orthogonal projections confirmed adequate device apposition, good wall conformability, and proper vessel reconstruction [Figure 4b]. Additionally, no residual filling of the ACom aneurysm was observed following WEB deployment, confirming immediate angiographic occlusion. No periprocedural complications were observed. CEA was performed [Video 1], followed by transfemoral DSA for further evaluation of the complex carotid circulation.

Figure 3:

a) DSA of the Left ICA working projection. Microcatheter positioned within the ACom aneurysm before deployment of the WEB device. b) Angiographic image demonstrating successful deployment of the WEB device within the aneurysm sac with complete neck coverage and adequate device configuration after microcatheter removal. DSA: Digital subtraction angiography; ICA: Internal carotid artery; WEB: Woven EndoBridge.

Figure 4:

a)Microcatheter positioned across supraclinoid ICA before p64 flow diverter deployment. The distal access catheter and distal microcatheter marker are identified. b) Final angiographic image immediately after p64 flow diverter deployment demonstrating adequate device apposition, preservation of the PCom artery, and absence of residual aneurysm filling. ICA: Internal carotid artery; PCom: Posterior communicating artery.

Angiographic control

Following CEA, a control DSA was performed via a right transfemoral approach. A 5 Fr × 15 cm sheath was placed, through a 5 Fr × 90 cm Simmons 2 diagnostic catheter was advanced over a 0.035-inch × 150 cm hydrophilic guidewire. Under fluoroscopic and roadmap guidance, selective catheterization of the left common carotid artery was achieved. Angiographic evaluation demonstrated restoration of luminal patency and full flow recovery, preservation of distal vascular anatomy without evidence of embolic complications, obliteration of the ACom aneurysm, and adequate apposition and conformability of the FD across the supraclinoid segment of the ICA. No evidence of endoleak or distal thromboembolic events was observed [Figure 5].

Figure 5:

a) DSA anterolateral view of the Left common carotid artery demonstrating restoration of carotid lumen patency and satisfactory reconstruction of the cervical ICA following CEA. (b) Left ICA DSA anteroposterior view demonstrating preserved intracranial circulation, complete occlusion of the ACom aneurysm, and adequate parent vessel reconstruction following p64 flow diverter deployment, and absence of thromboembolic complications. DSA: Digital subtraction angiography; ICA: Internal carotid artery; ACom: Anterior communicating artery; CEA: Carotid endarterectomy.

The patient remained under deep sedation (RASS -5) during the first 24 postoperative hours until the follow-up study was completed and hemodynamic stability was achieved. Follow-up CTA with reconstructions demonstrated adequate flow in the left ICA and appropriate positioning of the endovascular devices, with no evidence of cervical or intracranial hemorrhage. The patient was discharged after 72 h of postextubation monitoring with a GCS score of 15, no focal neurological deficits, and no hemodynamic complications during hospitalization.

DISCUSSION

Vascular neurosurgery currently integrates two main complementary modalities: open surgical and endovascular approaches. The evolution of these techniques has facilitated hybrid strategies that combine their respective advantages, enabling treatment of complex cerebrovascular pathologies that would otherwise be challenging or impossible to manage with a single approach alone.[1,3,9,32]

The coexistence of two vascular conflicts, UIA and CS, represents a true therapeutic dilemma rather than two independent findings. Revascularization may be dangerous not merely because flow increases, but because it may restore pressure and pulsatile energy to a chronically hypoperfused distal territory in which the aneurysm wall may have adapted to reduced inflow, thereby increasing the risk of cerebral hyperperfusion syndrome, postoperative hypertension, and intracerebral hemorrhage.[20,24] The review also highlights that the prevalence of UIAs in carotid disease is higher than previously assumed, making this problem clinically relevant rather than anecdotal.[34]

Although aneurysm rupture after CEA is considered a rare complication, available evidence suggests that this risk may not be negligible in selected patients, such as an up to 4% risk of aneurysm rupture in patients undergoing revascularization as demonstrated by a systematic review performed by Khan, et al. in 2012.[15] Antiplatelet therapy provides important evidence regarding treatment decision-making in patients with coexistent CS and small UIA (<10 mm). The risk of subarachnoid hemorrhage is low, and the 5-year risk of stroke following CEA is comparable to that of patients without UIAs.[14]

Treatment planning in patients with concomitant carotid occlusive disease and intracranial aneurysms should not be based solely on the presence of both lesions but rather on their hemodynamic interaction and the patient’s cerebrovascular reserve. Factors such as collateral circulation, parent vessel anatomy, access feasibility, cardiovascular comorbidities, and the potential risks associated with staged procedures should be considered when tailoring the therapeutic strategy.

In this case, we opted for a single-stage hybrid strategy consisting of aneurysm exclusion followed by definitive carotid reconstruction. After surgical exposure of the carotid bifurcation, intraoperative Doppler ultrasonography and direct inspection were used to identify a plaque-free ICA segment distal to the stenotic plaque, allowing controlled direct transcarotid puncture under immediate surgical control, providing a stable route for aneurysm treatment, while minimizing manipulation across the stenotic cervical carotid segment. Direct transcarotid access not only facilitated endovascular treatment but also provided immediate surgical control of the access site, minimized catheter manipulation across diseased vessels, and allowed seamless transition to carotid reconstruction during the same surgical stage, as previously described by other centers.[25,27] Once both aneurysms had been treated, CEA was performed in the same operative setting to restore carotid flow. A staged strategy was considered less favorable because it would have exposed the patient to a second anesthetic event despite significant cardiovascular comorbidity and would have required either leaving the aneurysms untreated during the early postrevascularization period or performing aneurysm treatment through conventional access in the setting of critical CS and complex supra-aortic disease. Both options were considered less favorable than a single-stage hybrid strategy.

The selection and tailoring of appropriate endovascular devices are driven mainly by aneurysm morphology, parent vessel anatomy, and the need to achieve definitive exclusion from the bloodstream. An intrasaccular WEB device was selected to treat the ACom aneurysm because the lesion was located at a bifurcation and had a wide neck. Technical reviews recommend oversizing the device width by 1–2 mm to achieve lateral compression and neck coverage, as well as a lower height relative to the aneurysm height, a strategy known as the “+1/−1” sizing principle.[10] This strategy is associated with stability and adequate apposition and occlusion. According to this principle, a 4 × 2 mm WEB device was selected, demonstrating satisfactory intrasaccular deployment and absence of residual filling.[8,22]

The supraclinoid ICA aneurysm demonstrated a small and wide-necked morphology that favored a reconstructive endovascular strategy. Flow diversion was selected because it allowed parent vessel reconstruction while avoiding the technical limitations of coil embolization in a patient with severely compromised carotid circulation. The p64 Flow Modulation Device has demonstrated favorable angiographic and clinical outcomes in selected intracranial aneurysms and represented an appropriate complement to the overall hybrid treatment strategy.[4,17]

In recent years, the indications for flow diversion have progressively expanded beyond large and giant ICA aneurysms to include small and wide-necked lesions with favorable angiographic and clinical outcomes. The p64 Flow Modulation Device has demonstrated high aneurysm occlusion rates and an acceptable safety profile in the treatment of intracranial aneurysms, frequently achieving complete aneurysm exclusion with a single device. In the present case, parent artery reconstruction with a p64 FD was considered the most appropriate treatment strategy because it addressed the aneurysm morphology while avoiding the technical limitations of coil embolization in the setting of a severely compromised carotid circulation. Adequate device apposition and wall conformability were confirmed angiographically, supporting successful vessel reconstruction within the overall hybrid treatment strategy.[5,6,31]

CEA remains a direct removal of the atherosclerotic plaque, providing immediate and durable luminal restoration while avoiding the challenges associated with navigating heavily calcified or tortuous vessels. It also eliminates the need for permanent intraluminal implants, thereby reducing the risk of in-stent restenosis, offering direct visualization and control of the vessel, which is particularly advantageous in complex cases, enabling precise management of the arterial wall and minimizing the risk of embolic complications.[11,30] A retrospective series of 97 patients with a mean age of 70 years reported an operative mortality rate of 1.9%, and at 12-month follow-up, no recurrent restenosis, pseudoaneurysm, or new strokes were observed.

Although there are reports of simultaneous management of CS and UIAs, most involve unilateral disease treated with exclusively endovascular strategies or less extensive combinations.[19] Our case presents distinctive features: critical bilateral carotid artery disease with vertebral involvement, simultaneous presence of wide-necked and saccular unruptured aneurysms, use of direct carotid access to the ICA, and complete resolution in a single hybrid procedure. The available evidence remains limited to low-level data, including small series and case reports, which limits the generalizability of this strategy. Its use should be individualized and restricted to centers with expertise in complex cerebrovascular surgery and neurointerventional procedures.[11]

CONCLUSION

Single-stage hybrid management may represent an effective treatment strategy in selected patients with severe cervicocerebral occlusive disease and concomitant intracranial aneurysms when conventional endovascular or staged approaches are technically unfavorable. Although current evidence remains limited to small series and case reports, careful assessment of collateral circulation, hemodynamic status, and vascular anatomy is essential for treatment planning. Direct transcarotid access can provide a safe and versatile route for aneurysm treatment and carotid reconstruction in a single operative setting.

Ethical approval:

Institutional Review Board approval is not required.

Declaration of patient consent:

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for their images and other clinical information to be reported in the journal. The patient understands that the patient’s names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship:

Nil.

Conflicts of interest:

There are no conflicts of interest.

Use of artificial intelligence (AI)-assisted technology for manuscript preparation:

The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.

Video available on:

https://doi.org/10.25259/SNI_631_2026

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