Since the release of the most recent European Society of Cardiology (ESC) and European Association for Cardio-Thoracic Surgery (EACTS) guidelines on valvular heart disease, transcatheter aortic valve implantation (TAVI) has become an integral part of daily clinical practice in all heart team discussions. This is particularly true when considering patients older than 70 years for conventional surgical aortic valve replacement.

From 2025 onward, transfemoral TAVI has been positioned as the predominant approach, with a class I recommendation and level of evidence “A” for all patients above 70 years, irrespective of surgical risk. Those with unsuitable iliofemoral anatomy are relegated to so-called “nonfemoral” approaches. However, the optimal vascular access in this subset remains uncertain. Available evidence varies across registries and centers, evolving in parallel with technical refinements. Currently, the transaxillary approach predominates, although in recent years the transcarotid route has emerged as a highly promising alternative.

The present retrospective, single-center study from Lausanne University Hospital analyzed patients from the SWISS TAVI Registry between 2018 and 2021 with severe aortic stenosis. Following multidisciplinary heart team assessment, candidates were deemed unsuitable for transfemoral TAVI and thus underwent implantation through a nonfemoral pathway.

In these patients, the procedure was performed using either the right or left transcarotid approach. The aim was to compare two preoperative CT angiography parameters—tortuosity level and plaque burden—in the left common carotid artery (LCCA), right common carotid artery (RCCA), and the aortic annulus, in order to assess their implications for access complexity, procedural performance, and outcomes.

1. Tortuosity level.This parameter was subdivided into two objective metrics:
2. a)Tortuosity index (TI):previously validated in studies of aortic disease, based on software-derived measurements and 3D reconstructions between points A and C (corresponding to the theoretical puncture sites on the right and left carotid arteries, respectively) and point B (center of the aortic annulus). A value of 1 represents the lowest possible tortuosity, with higher values indicating increasing tortuosity. This metric is relatively stable and not significantly influenced by interobserver variability.
3. b)Sum of angles metric:based on 3D reconstructions, each vessel curvature angle was measured and added along the pathway to the aortic annulus. Angulation was categorized as severe (<30°), moderate (30–60°), or mild (>60°). The vessel with the smaller total angular value was considered more tortuous. The authors noted that this metric is more prone to interobserver variability compared with TI and should therefore be interpreted with caution.
4. Plaque burden.Defined as the presence of any plaque in the vessel, regardless of number, morphology, or degree of stenosis, except when clinically relevant.

Results: Among the 46 patients who underwent either right or left transcarotid TAVI, no significant differences were observed in mean TI between the left and right sides (1.20 vs 1.19; p = .82), mean sum of angles (left: 396°, right: 384°; p= .27), or prevalence of arterial plaque (30% in the LCCA vs 45% in the RCCA; p = .19).

Similarly, no significant differences were found in mean minimum vessel diameters (6.57 mm vs 6.74 mm; p = .92) or maximum diameters (7.29 mm vs 7.55 mm; p = .72) between the LCCA and RCCA.

Postoperative outcomes were not compared between the two groups because of the small number of patients undergoing left transcarotid TAVI (6.5% of cases).

The authors concluded that their data did not provide sufficient evidence to recommend one carotid artery over the other for transcarotid TAVI. Instead, integration of multiple parameters—including vessel tortuosity and plaque burden—should guide the individualized selection of the access side within a multidisciplinary framework.

COMMENTARY:

First, it is worth emphasizing the objective use of parameters that are often regarded as qualitative vessel features during TAVI planning. The tortuosity index, sum of angles, and plaque burden can serve as reproducible, quantifiable tools to support heart team discussions. They may help not only when comparing alternative nonfemoral access routes, as in this study, but also in borderline transfemoral cases where feasibility is uncertain or potential complications are anticipated.

Second, it is noteworthy that in 94% of cases the right carotid access was chosen, compared with only 6% using the left carotid, a distribution opposite to what is typically reported in other centers. This preference was justified by improved maneuverability of the delivery system via the right carotid artery, owing to its shorter and more direct alignment with the aortic annulus. The left carotid was reserved only when unfavorable angulation or significant vessel calcification was present. It should also be noted that 100% of valves implanted in this series were balloon-expandable prostheses (SAPIEN Ultra® and SAPIEN 3®).

In our own TAVI program at Puerta del Mar University Hospital, both right and left transcarotid routes are considered equally valid. However, the right carotid approach is particularly advantageous in patients with an aortic annulus–horizontal axis angle greater than 55°, a situation colloquially referred to as a “horizontal aorta.” New-generation SAPIEN® prostheses, besides their favorable profile and maneuverability, benefit from the Certitude® delivery system, which offers an articulated flexion mechanism that facilitates optimal annular alignment. This feature can be crucial in anatomically challenging cases, reducing the risk of paravalvular leak.

Third, the authors correctly highlight that supra-aortic tortuosity is associated with well-known cardiovascular risk factors frequently encountered in TAVI candidates, such as advanced age, diabetes mellitus, and hypertension. Progressive loss of height and the resulting changes in anatomical relationships contribute to carotid tortuosity. These factors may also predict vascular access complications, as observed with transfemoral TAVI.

From our experience, left carotid access—once surgical exposure and vessel control are achieved—allows gentle traction of the artery (provided there is no severe calcification). This maneuver can reduce angulation that might otherwise appear prohibitive on imaging. Similarly, the use of a stiff guidewire may help straighten the vessel pathway, particularly in the absence of extensive calcification.

Finally, this study underscores the central role of the multidisciplinary heart team, which in this context included at least an interventional cardiologist, a cardiac surgeon, and an expert echocardiographer. Current guidelines grant the highest level of evidence and recommendation to decision-making based on heart team assessment. Therefore, the consistent establishment of such teams in every TAVI center is essential to ensure optimal patient safety and care quality.

REFERENCE:

Salihu A, Rotzinger DC, Fahrni G, Nowacka A, Antiochos P, Fournier S, et al. Transcarotid vascular access for transcatheter aortic valve implantation: is choosing the left side always right? J Cardiothorac Surg. 2024 Apr 10;19(1):196. doi: 10.1186/s13019-024-02661-7.