Abstract
In this issue of
TCAR received approval by the Food and Drug Administration (FDA) in 2015 for high-risk patients with carotid artery stenosis. As part of TCAR’s FDA approval process, the TCAR Surveillance Project was initiated in 2016, which stipulates that all patients undergoing TCAR have their procedural data entered in the Vascular Quality Initiative (VQI) registry. 2 The indication for TCAR was subsequently expanded in 2022 to include standard-risk patients. A recent study aiming to document trends in TCAR utilization from January 1, 2016 until March 31, 2022 demonstrated a dramatic increase in TCAR performance, from 29 centers at the end of 2016 to 606 centers in March 2022. 3 The total number of implants similarly increased from 131 at the end of 2016 to a total of 31,447 at the end of March 2022. 3 TCAR accounted for a steadily rising percentage of the total carotid interventions. In quarter 1 of 2016, TCAR represented 1.0% of all carotid procedures and this increased to 23.9% in quarter 1 of 2022 (P trend < .001). 3
Similar to the study by Loufopoulos et al., 1 a recent systematic review and study-level meta-analysis included studies published between January 2000 and February 2023 that used TCAR, CEA, or transfemoral carotid artery stenting (CAS) for the treatment of patients with symptomatic internal carotid artery stenosis (n = 7 studies; 24,246 patients). 4 Within this patient cohort, 4771 individuals underwent TCAR, 12,350 underwent CEA, and 7125 patients underwent CAS. 4 Compared with CEA, TCAR was associated with a higher rate of stroke or transient ischemic attack (OR: 1.26; 95% CI: 1.03–1.54; P < .01), but similar rates of MI (OR: 0.9; 95% CI .64–1.38; P = not significant) and mortality (OR: 1.35; 95% CI: 0.87–2.10; P = not significant) were observed. 4 In contrast, when compared with transfemoral CAS, TCAR was associated with a similar rate of stroke or transient ischemic attack (OR: .77; 95% CI: 0.33–1.82; P = not significant) and MI (OR: 1.29; 95% CI: 0.83–2.01; P = not significant) but lower mortality rates (OR: .42; 95% CI: .22-.81; P < .001). 4
In their systematic review and meta-analysis, Loufopoulos et al. report that TCAR and CEA are similar in terms of mortality, stroke, and the combination of mortality and major adverse cardiovascular event rates. 1 These conclusions mirror the conclusions of a recent propensity-score matched analysis that used VQI TCAR Surveillance Project data to compare outcomes after TCAR and CEA (n = 6384 procedures in each treatment arm). 5 This propensity-score analysis similarly found no differences between the two procedures in terms of in-hospital stroke/death (1.6 vs 1.6%, for TCAR vs CEA, respectively; relative risk [RR]: 1.01; 95% CI: 0.77–1.33; P = .945), stroke (1.4 vs 1.4%, for TCAR vs CEA, respectively; RR: 1.02; 95% CI .76–1.37; P = .881), and death (0.4 vs 0.3%, for TCAR vs CEA, respectively; RR: 1.14; 95% CI: 0.64–2.02; P = .662). 5 Compared with CEA, TCAR was associated with lower rates of in-hospital MI (.5 vs 0.9%, for TCAR vs CEA, respectively; RR: .53; 95% CI: .35–.83; P = .005), cranial nerve injury (.4 vs 2.7%, for TCAR vs CEA, respectively; RR: .14; 95% CI: .08–.23; P < .001), and post-procedural hypertension (13 vs 18.8%, for TCAR vs CEA, respectively; RR: .69; 95% CI: .63–.76; P < .001). Patients undergoing TCAR were also less likely to stay in hospital for >1 day (26.4 vs 30.1%, for TCAR vs CEA, respectively; RR: 0.88; 95% CI: 0.82–0.94; P < .001). 5
An earlier systematic review and meta-analysis (n = 9 non-randomized studies; 4012 TCAR patients) demonstrated 30-day stroke/death rates after TCAR of 1.89% (95% CI: 1.50–2.37), 30-day stroke rates of 1.34% (95% CI: 1.02–1.75), 30-day death rates of 0.76% (95% CI: 0.56–1.08), 30-day MI rates of 0.60% (95% CI: 0.23–1.59), 30-day stroke/death/MI rates of 2.20% (95% CI: 1.31–3.69), and cranial nerve injury rates of 0.31% (95% CI: 0.23–1.59). 6 Two non-randomized studies comparing 30-day outcomes after TCAR vs transfemoral CAS reported lower overall stroke risk for TCAR than transfemoral CAS (1.33 vs 2.55%, respectively; OR: .52; 95% CI: .37–.74; P < .01) and lower risk of death (.76 vs 1.46%, respectively; OR: .52; 95% CI: .32–0.84; P < .01). 6 Furthermore, three non-randomized studies comparing TCAR vs CEA demonstrated that TCAR is associated with a lower rate of cranial nerve injury than CEA (.54 vs 1.84%, respectively; OR: .52; 95% CI: .36–0.74; P < .01). 6
TCAR has certain anatomic requirements and limitations. 7–9 Anatomic requirements include a ≥5-cm clavicle-to-carotid bifurcation distance, minimal plaque at the common carotid artery puncture site, and a ≥6-mm common and a ≥4-mm internal carotid artery diameter. TCAR limitations include excessive calcification, carotid artery tortuosity, and fresh thrombus. 7–9 Nevertheless, nearly 75% of patients are eligible for TCAR. 6 On the other hand, CEA can be challenging in patients with tracheal stoma, high carotid bifurcation, neck irradiation, previous CEA, or prior neck surgery. 9 Therefore, the two procedures have a complimentary (rather than an antagonistic) role in the management of patients with carotid stenosis. It was demonstrated that adoption of TCAR as an additional procedural option for patients with carotid stenosis may be associated with lower rates of perioperative adverse events. 10 At present, anatomy is the primary criterion when choosing a carotid revascularization option, followed by patient preference. Further studies are required to determine the best treatment option for patients who are anatomically suitable for either procedure.
One drawback of TCAR is its higher cost than either transfemoral CAS or CEA. 11,12 However, although 5-year costs for TCAR are greater than CEA, it was demonstrated that TCAR affords greater quality-adjusted life years than CEA. 11 Unfortunately, TCAR was recently withdrawn from the European market by Silk Road Medical, thus limiting its use outside the United States. 13 Hopefully, this decision will change in the future in order to provide another alternative therapeutic option to carotid patients.
In conclusion, the systematic review and meta-analysis by Loufopoulos et al. provide an updated report about 30-day outcomes of TCAR compared with CEA. A randomized-controlled trial comparing TCAR vs CEA vs transfemoral CAS is needed to obtain Level-I evidence about the comparative efficacy of each procedure.
Footnotes
Declaration of conflicting interests
The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Marc L. Schermerhorn is the Principal Investigator of the ROADSTER-3 trial and is the Chair of the TCAR Surveillance Project in the Vascular Quality Initiative. Mahmoud B. Malas is the co-Chair of the TCAR Surveillance Project. Kosmas I. Paraskevas has no conflicts of interest.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
