The Learning Curve for Transcarotid Artery Revascularization Is Not Affected by Prior Transfemoral Carotid Artery Stenting Experience

Recent studies have established a learning curve for transcarotid artery revascularization (TCAR). However, these studies do not account for a surgeon’s prior experience with transfemoral carotid artery stenting (tfCAS). Therefore, we assessed the effect of prior tfCAS experience on the TCAR learning curve. We identified all TCAR procedures in the Vascular Quality Initiative TCAR Surveillance Project (2016-2021) performed at centers that also performed tfCAS before the adoption of TCAR. Repairs were stratified by the TCAR learning curve, and outcomes were then compared by prior tfCAS experience (any vs none). Based on prior work, the TCAR learning curve was defined by total TCAR cases: novice (1-5), intermediate (6-20), or advanced (>20). Of 10,413 TCARs, 22% were performed at the novice TCAR experience level, 35% at the intermediate level, and 43% at the advanced level. Of all TCARs, 55% were performed by surgeons with no prior tfCAS experience (Fig). At the novice TCAR level, surgeons with any prior tfCAS experience were less likely to use intraoperative protamine (71% vs 81%; P < .001) and were more likely to operate on patients considered anatomically high risk for carotid enterectomy (CEA) (50% vs 45%; P = .029) (Table). There was no difference in postoperative stroke/death regardless of prior tfCAS experience (1.7% vs 1.3%; P = .55). At the intermediate TCAR level, surgeons with any prior tfCAS experience were less likely to use intraoperative protamine (77% vs 86%; P < .001) and more likely to operate on a patient considered anatomically high risk for CEA (50% vs 44%; P < .001). However, in the intermediate TCAR group, surgeons with any prior tfCAS experience had a shorter median flow reversal time when compared with surgeons with no prior tfCAS experience (9 minutes [interquartile range (IQR): 7, 12] vs 10 minutes [IQR: 8, 14]; P < .001). There was no difference in postoperative stroke/death regardless of prior tfCAS experience (1.9% vs 2.2%; P = .59). At the advanced TCAR level, surgeons with any prior tfCAS experience were less likely to use intraoperative protamine (87% vs 91%; P = .009) and more likely to operative on a patient considered anatomically high risk for CEA (47% vs 41%; P < .001). Surgeons with any prior tfCAS experience had a shorter median flow reversal time when compared with surgeons with no prior tfCAS experience (8 minutes [IQR: 6, 11] vs 9 minutes [IQR: 6, 12]; P = .009). There was no difference in postoperative stroke/death regardless of prior tfCAS experience (2.0% vs 1.5%; P = .25). TCAR is a safe option for carotid artery revascularization, even when completed by novice-level TCAR providers, including those with no prior tfCAS experience.TablePostoperative and intraoperative outcomes after transcarotid artery revascularization (TCAR), stratified by TCAR learning curve and prior transfemoral carotid artery stenting (tfCAS) experienceTCAR by novice-level TCAR surgeonPrior tfCAS experience (N = 598)No tfCAS experience (N = 1721)P valueProtamine, %7181<.001Flow reversal time (IQR)10 (7, 13)10 (8, 14).002Anatomic high risk, %5045.029Medical high risk, %4748.70Stroke/death, %1.71.3.55TCAR by intermediate-level TCAR surgeonPrior tfCAS experience (N = 1307)No tfCAS experience (N = 2343)P valueProtamine, %7786<.001Flow reversal time (IQR)9 (7, 12)10 (8, 14)<.001Anatomic high risk, %5044.001Medical high risk, %4551<.001Stroke/death, %1.92.2.59TCAR by advanced-level TCAR surgeonPrior tfCAS experience (N = 2821)No tfCAS experience (N = 1623)P valueProtamine, %8791<.001Flow reversal time (IQR)8 (6, 11)9 (6, 12).009Anatomic high risk, %4741<.001Medical high risk, %5559.005Stroke/death, %2.01.5.25IQR, Interquartile range. Open table in a new tab