Carotid Stenting and Transcarotid Artery Revascularization

32.1From modality choice to route choice: where transfemoral stenting and transcarotid revascularisation actually fit

The route decision begins only after the indication decision has been made. A patient with carotid stenosis first needs a defensible reason to undergo revascularization at all, with symptom status, timing after stroke or TIA, stenosis severity, medical therapy, life expectancy, and the center’s peri-procedural stroke-or-death performance all weighed against non-operative care. Contemporary guidelines prioritise this initial decision and treat peri-procedural quality as a gatekeeper Editor's Choice European 2023 · SVS 2022 · AHA 2021 · ACC/AHA 2011.

Once intervention is justified, stent-based treatments should not be compressed into a single category. Transfemoral carotid stenting and transcarotid artery revascularization both leave a carotid stent across the lesion, but they are different operations at the points that matter clinically: how the lesion is reached, when embolic protection begins, what anatomy is made hazardous by the access route, and what kind of comparative data support the choice. Transfemoral stenting asks the operator to traverse the iliofemoral system, aortic arch, great-vessel origin, and carotid lesion before the stent is deployed; the dominant hazards are arch manipulation, common-carotid tortuosity, plaque crossing, and the limits of distal filter protection. Transcarotid revascularization bypasses the arch by exposing the common carotid in the neck and establishing flow reversal before lesion crossing, so the access burden shifts from arch navigation to a hybrid neck procedure with carotid clamping and team familiarity with flow-reversal physiology Editor's Choice European 2023 · TCAR 2019.

The clinical sequence involves a three-step comparison. First, decide which evidence population the patient resembles: recently symptomatic severe stenosis, asymptomatic severe stenosis selected for intervention, or high-surgical-risk disease. Second, decide whether endarterectomy is the safer comparator, especially in older symptomatic patients, or whether cardiac comorbidity, hostile neck features, prior surgery, or other surgical-risk features make a stent-based option reasonable. Third, decide whether a stent-based plan should be transfemoral or transcarotid. That final distinction is largely an anatomic and procedural one, especially when a diseased or tortuous arch makes transfemoral access the part of the operation most likely to generate embolic risk Editor's Choice European 2023 · SVS 2022.

32.2Trial cohorts, eras, and what they actually settle

The randomized data for carotid stenting should be interpreted by cohort. CREST enrolled both symptomatic and asymptomatic patients and found a broadly similar primary composite for stenting and endarterectomy, including long-term durability of the composite result, but the peri-procedural signature was different: stenting carried more stroke, whereas endarterectomy carried more myocardial infarction CREST 2016 · CREST · 2010. This distinction is clinically significant. Stroke and myocardial infarction have different implications for the patient’s values, disability risk, anesthetic risk, and expected recovery, so CREST usually informs a discussion of competing peri-procedural harms rather than a simple declaration that the two operations are identical.

The symptomatic European trials are more cautionary for transfemoral stenting. ICSS randomized symptomatic patients and reported higher early stroke, myocardial infarction, or death after stenting than after endarterectomy; its long-term follow-up helps separate the early procedural hazard from later ipsilateral-stroke prevention, but the peri-procedural signal remains central to how symptomatic patients are counselled Long-term outcomes after 2015 · ICSS · 2010. EVA-3S was stopped early because 30-day stroke or death was excessive after stenting compared with endarterectomy in symptomatic severe stenosis, and SPACE did not demonstrate non-inferiority of stent-protected angioplasty versus endarterectomy at 30 days within its prespecified design Endarterectomy versus Stenting 2006 · SPACE (30-day) 2006. Taken together, these trials explain why a recently symptomatic, standard-surgical-risk older patient is usually not a neutral candidate for transfemoral stenting merely because a stent can be technically placed.

SAPPHIRE addresses a different clinical scenario. It enrolled patients judged to be at high surgical risk and reported non-inferiority of protected carotid stenting against endarterectomy for a 30-day composite of stroke, myocardial infarction, and death Protected Carotid-Artery Stenting 2004. Its value is that it legitimises a stent-based discussion when endarterectomy risk is unusually high; its limitation is that the high-risk study population is not the same as a routine symptomatic carotid clinic. Using SAPPHIRE to override the symptomatic-trial stroke signal in standard-risk patients is a category error.

The pooled evidence reinforces that reading. The Cochrane comparison concluded that carotid stenting carries higher peri-procedural stroke risk than endarterectomy while long-term non-procedural stroke rates are broadly similar Carotid artery stenting 2020. ACST-2 then adds the asymptomatic comparator: in selected asymptomatic patients treated in centers meeting experience criteria, stenting and endarterectomy produced similar peri-procedural and 5-year non-disabling stroke outcomes Second asymptomatic carotid 2021. Consequently, symptom status, operator experience, age, and the early hazard window determine which trial result applies to the individual patient.

32.3Matching the patient to the route: symptom status, age, arch, and surgical risk

Route selection depends on several clinical axes. The first is symptom status and timing. A recently symptomatic patient with severe stenosis is being treated primarily to prevent early recurrent stroke, so peri-procedural stroke is the dominant currency of comparison; in that setting the symptomatic randomized trials and the pooled comparisons generally favor endarterectomy when surgical risk is acceptable Carotid artery stenting 2020 · ICSS · 2010 · Endarterectomy versus Stenting 2006 · SPACE (30-day) 2006. An asymptomatic patient, by contrast, enters a slower-benefit calculation in which life expectancy, contemporary medical therapy, and center outcomes must already justify intervention before the route question is meaningful; ACST-2 informs the route comparison among selected asymptomatic patients, not the decision to intervene in every asymptomatic stenosis Second asymptomatic carotid 2021.

The second axis is age. CREST identified age as a treatment-effect modifier, with patients aged 70 years and above experiencing worse peri-procedural outcomes after carotid stenting, mainly through the stroke component CREST 2016 · CREST · 2010. In practice, that finding makes endarterectomy the default comparator for many older symptomatic patients when the neck is surgically reasonable and local results meet accepted peri-procedural standards. The mechanism is multifactorial: older patients more often have arch elongation, calcification, tortuosity, and plaque burden, all of which make transfemoral navigation more hazardous. The trial signal should therefore be interpreted as a clinical warning about the whole access path rather than as a biological age rule that can be ignored once the lesion itself looks focal.

The third axis is surgical risk. Stenting becomes more attractive when endarterectomy carries excess risk from serious cardiac comorbidity or from clearly documented features that make open repair unusually hazardous. SAPPHIRE supports stenting in a high-surgical-risk population, but that support is conditional on the patient resembling the enrolled risk profile and on the center achieving low peri-procedural stroke and death rates Protected Carotid-Artery Stenting 2004. A high-risk label should therefore be specific. Systemic operative risk differs from a hostile transfemoral access path; the former may preclude endarterectomy, while the latter may preclude transfemoral stenting.

The fourth axis is anatomy, and it often determines whether a stent-based plan should be transfemoral or transcarotid. Heavy arch atheroma or calcification, difficult great-vessel origin, severe tortuosity, and common-carotid disease increase the risk of transfemoral manipulation; current society framing places transcarotid artery revascularization in the access lane for patients in whom the arch is the problem to avoid rather than the corridor to use Editor's Choice European 2023 · SVS 2022. All of this depends on confirming the stenosis correctly. Duplex ultrasound should be interpreted using consensus velocity and imaging criteria, and discordance between duplex and cross-sectional imaging should be resolved before the patient is assigned to any procedural route Carotid Artery Stenosis 2003.

32.4Transcarotid artery revascularisation as a different access lane, not a different stenting device

Transcarotid artery revascularization alters the procedural approach before stent deployment. The common carotid artery is exposed surgically in the neck, cerebral protection is established with dynamic flow reversal before the lesion is crossed, and the stent is delivered without the long transfemoral path through the arch Editor's Choice European 2023 · TCAR 2019. That distinction matters most in the patient whose greatest procedural risk lies between the femoral artery and the carotid lesion: atheromatous arch, tortuous great vessels, difficult common-carotid origin, or anatomy that makes catheter stability poor. For such a patient, transcarotid access allows the operator to cross the plaque under a different protection strategy, avoiding a substantial portion of the embolic access path.

The embolic-protection logic is different from distal filter protection. In transfemoral stenting, a distal filter is deployed only after the access system has reached the carotid circulation and the lesion has been crossed sufficiently to place protection; embolic material can still be generated during arch manipulation, wire passage, and the unprotected part of lesion crossing. The ICSS diffusion-weighted MRI substudy showed a greater burden of new ischemic brain lesions after stenting than after endarterectomy, and embolic-protection comparisons from that era help explain why protection strategy is not a trivial device detail New ischaemic brain 2010 · ICSS · 2010. Flow reversal addresses this exposure window from the proximal side, but it introduces its own requirements: neck exposure, carotid control, tolerance of altered flow during the protected phase, and a team that can move fluently between open vascular control and endovascular precision.

The data supporting transcarotid revascularization should be used with the same anatomic clarity. Large registry analyses report better peri-procedural stroke-or-death outcomes for transcarotid revascularization than for transfemoral stenting in contemporary practice, which is clinically important when choosing between stent-based routes TCAR 2019. The same result should not be inflated into randomized equivalence with endarterectomy. Registry comparisons are affected by patient selection, center adoption, operator experience, coding, and the possibility that the very anatomy making transfemoral access hazardous also determines who is offered transcarotid treatment. When a stent-based procedure is appropriate and transfemoral arch navigation is hazardous, transcarotid revascularization is generally the preferred endovascular route; when endarterectomy is the main comparator, the limitations of registry data must be acknowledged Editor's Choice European 2023 · SVS 2022.

Route selection also requires a clear consent comparison. The patient should hear which comparison is actually being made: endarterectomy versus transfemoral stenting in the randomized symptomatic data, stent-based route selection when arch-hostile anatomy makes transfemoral passage hazardous, or intervention-route choice in selected asymptomatic disease. Naming that comparison prevents registry-based transcarotid outcomes from being used as if they were randomized proof against endarterectomy and keeps local peri-procedural performance in the discussion CREST · 2010 · ICSS · 2010 · TCAR 2019.