Transcarotid Artery Revascularization Procedure Research Articles

An evolution in carotid care: Contemporary TCAR data and optimization techniques

ObjectiveCarotid endarterectomy (CEA) is the gold standard for revascularization of atherosclerotic extra-cranial carotid artery lesions. The introduction of transfemoral carotid artery stenting (TFCAS) led to multiple randomized controlled trials to compare the safety and efficacy of an endovascular approach against traditional CEA in the management of carotid artery stenosis. The operative management of carotid artery stenosis continues to evolve, with the more recent introduction of TransCarotid artery revascularization (TCAR) and a novel flow-reversal neuroprotection system. This manuscript reviews a brief history regarding carotid artery revascularization, as well as the indications, technical considerations, and clinical outcomes of the TCAR procedure. Technical considerationsThe preoperative, intraoperative, and postoperative medical and technical considerations are explored. Topics of discussion will include the indications and contraindications for TCAR, anatomic requirements, instructions for use (IFU) and off-label utility, optimal pharmacologic regimen with carotid stent placement, standard deployment and suggestions for hostile anatomy, as well as recommended postoperative management and surveillance imaging. DiscussionThe Society for Vascular Surgery (SVS) has published a consensus statement on the pathways available to obtain clinical competency and maintain technical proficiency with TCAR. Meta-analyses reviewing the contemporary technical success and clinical outcomes of TCAR have demonstrated high rates of procedural success and low rates of stroke, myocardial infarction, and death. Studies have further illustrated comparable one-year rates of peri‑procedural stroke between TCAR and CEA, for asymptomatic and symptomatic carotid lesions, with both outperforming TFCAS. ConclusionManagement of extra-cranial carotid artery stenosis utilizing TCAR with the ENROUTE flow-reversal neuroprotection system has been widely adopted, yielding clinical outcomes and stroke prevention similar to traditional CEA and superior to TFCAS.

Abstract P453: Racial Disparities in Early Use of Transcarotid Artery Revascularization Among High-Risk and Symptomatic Black and White Adults With Carotid Artery Stenosis

Introduction: Differential access to new technologies may contribute to racial disparities in health outcomes. We examined the adoption of transcarotid artery revascularization (TCAR) among high-risk Black and white adults undergoing surgery for carotid artery stenosis. Hypothesis: We hypothesized that Black adults would be less likely than white adults to receive TCAR since its introduction to the US market in 2015. Methods: We conducted a retrospective analysis of the prospectively collected Vascular Quality Initiative surgical database from 1/2015 to 12/2021, which includes 100% of the TCAR procedures performed during this period. Non-Hispanic Black and non-Hispanic white adults were included if they met Centers for Medicare & Medicaid Services high-risk criteria due to anatomy, medical comorbidities, and/or recent symptoms (ipsilateral stroke or transient ischemic attack). We used logistic regression to quantify associations of race with receipt of TCAR (versus other surgical procedure for carotid stenosis) overall and by specific high-risk features. Results: There were 119,128 surgical procedures performed for carotid artery stenosis (14.3% TCAR) (mean age 72 years, 5.3% Black, 38.5% female). Black patients were less likely than white patients to receive TCAR after adjustment for patient and disease characteristics (aOR 0.91, 95% CI 0.83, 0.99). Among patients with only one high-risk feature (e.g., only high-risk anatomy), TCAR use did not vary by race. However, Black patients were less likely to receive TCAR in subgroups with multiple high-risk features ( Figure ). Not all hospitals performed TCAR, and Black patients were less likely to be treated at TCAR-capable hospitals (aOR 0.93, 95% CI 0.88, 0.98). TCAR use did not vary by race at TCAR-capable hospitals ( Figure ). Conclusions: Adoption of TCAR was lower among Black compared to white high-risk patients, for whom TCAR offers the most benefit. Differential access to hospitals with newer technology may explain these disparities.

Diagnostic accuracy of intraoperative neuromonitoring in transcarotid artery revascularization

BackgroundIn recent years, transcarotid artery revascularization (TCAR) has emerged as a safe and effective alternative to carotid artery stenting. While intraoperative neuromonitoring (IONM) techniques such as electroencephalogram (EEG) and somatosensory...

Carotid artery dissections from transcarotid artery revascularization as reported by the Food and Drug Administration.

Transcarotid artery revascularization (TCAR) is a hybrid procedure that allows reversal of blood flow away from the brain while placing a stent through direct surgical access of the common carotid artery. It has been shown to have a lower risk of perioperative stroke compared with any prospective trial of transfemoral carotid artery stenting. However, intraoperative injuries related to the procedure and its management are not well characterized. One of the intraoperative complications seen in TCAR is iatrogenic carotid artery dissection (CD). We aim to add qualitative insight in further characterizing CDs and its management in this emerging technology. The Food and Drug Administration (FDA) maintains the Manufacturer and User Facility Device Experience (MAUDE) database for surveillance of all medical devices approved for use. This database was queried for all cases associated with Silk Road Medical's ENROUTE Transcarotid Neuroprotection System from September 2016 to October 2020. Case narratives related to CD were individually analyzed to determine time of injury (intraoperative, recovery, and post-discharge follow-up). CD reporting was further analyzed for the associated procedural event at the time of injury, number of access attempts to CD repair, and type of CD repair. Reports associated with CD repair were further categorized into endovascular repair and open surgical repair. Of the 115 unique adverse events in the database, there were 58 CDs. Most were identified intraoperatively (n = 55), while three were incidentally found postoperatively. Overall, sheath placement was the most common procedural event attributed to CD (N = 34). There was adequate narrative information about CD repair in 54 patients. Intraoperative repair was performed in 52 cases and two were repaired after post-discharge follow-up imaging was performed.Among CDs that did not require additional access to engage the true lumen, the proportion of endovascular repair (62.5%) was significantly higher (p = .044) compared to the proportion of open surgical repair (37.5%). However, the proportion of open surgical repair (75%) was significantly higher than the proportion of endovascular repair (25%) in CDs with persistent failure to engage the true lumen despite ≥2 access attempts (p = .039). CD is the most common injury related to TCAR as reported on MAUDE. The most commonly reported procedural event associated with CD was sheath placement. The rate of intraoperative endovascular and open surgical CD repair was associated with whether the access to the true lumen of the carotid artery required additional access attempts or not. This should add qualitative insight among the vascular surgery community regarding intraoperative management of CDs from a TCAR procedure.

An Artificial Intelligence-Aided Robotic Platform for Ultrasound-Guided Transcarotid Revascularization

Transcarotid Artery Revascularization (TCAR) is typically performed by manual catheter insertion and implies radiation exposure for both the patient and the surgeon. Taking advantage from robotics and artificial intelligence (AI), this letter presents a robotic ultrasound (RUS) platform for improving the procedure. To this purpose, ultrasound (US) imaging is considered both in the pre-operative stage for procedure planning and in the intra-operative stage to track a catheter. 3D vascular volumes can be precisely reconstructed from sequences of 2D images exploiting robotic probe manipulation and AI-based image analysis. The method proved a median reconstruction error lower than 1 mm. Pre-operative information are mapped to the intra-operative scenario thanks to a US-based registration routine. The automatic probe alignment on the target vessel demonstrated to be as precise as 0.84°. The reconstructed 3D model can be exploited to automatically generate a catheter trajectory based on user inputs. Such trajectory enabled automatic insertion of a magnetic catheter steered by an external permanent magnet actuated by the RUS platform. Our results demonstrate a catheter tip target reaching error of 3.3 mm. We believe that these results can open the way for the introduction of robotics and AI in TCAR procedures enabling precise and automatic small-scale intravascular devices control.

Evaluating the Safety of Transcarotid Artery Revascularization under Local Anesthesia Prior to Coronary Artery Bypass Grafting Surgery

Controversy exists regarding the timing of intervention for patients with critical coronary artery disease awaiting coronary artery bypass and severe carotid artery stenosis. Transcarotid artery revascularization (TCAR) is a minimally invasive revascularization alternative through direct transcervical carotid access that minimizes the chance of arch manipulation and consequent antegrade embolic stroke rate. While the TCAR procedure can be performed under local anesthesia (monitored anesthesia care, MAC) vs general anesthesia, the hemodynamic benefits of local anesthesia in patients with severe CAD are significant. Patients receiving staged TCAR-CABG have high-risk cardiovascular disease and require accurate perioperative neurological and hemodynamic evaluation that can be safely provided with local anesthesia. In this retrospective single-center study, 14 patients were systematically identified to have undergone staged TCAR prior to CABG surgery from December 2018 to October 2021. All patients underwent TCAR with local anesthesia and minimal sedation. Relevant patient demographics, medical and surgical history, preoperative covariates, and type of anesthesia administered were obtained from patients' charts. Carotid artery disease was confirmed by either carotid duplex imaging or computed tomography angiography (CTA) of the head/neck. Staged TCAR-CABG interventions were performed on 14 patients (64% male; mean age 65.0 years). No major adverse cardiac events were reported including transient ischemic attack (TIA), stroke, myocardial infarction, or TCAR-related death in the interval between their TCAR and CABG as well as in a 12-month follow-up period. One patient required to return to the operating room (OR) for evacuation of a neck hematoma. This study demonstrated high success rate of TCAR under local anesthesia prior to CABG (100%) with no incidence of perioperative stroke, myocardial infarction (MI), or death at 1-month, 6-month, and 12-month follow-up intervals. The authors support the use of staged TCAR-CABG with local anesthesia as a safe and promising treatment option for patients with high-grade cardiac disease, high risk of stroke, or multiple comorbidities that preclude a CEA.

Dual Antiplatelet Alternatives are Associated With Increased Stroke and Death After Transcarotid Revascularization.

To define the risks associated with the replacement of dual antiplatelets for alternate medication regimens. Patients undergoing transcarotid artery revascularization (TCAR) for atherosclerotic disease in the Vascular Quality Initiative database from September 2016 to June 2022 were included. In all, 29,802 TCAR procedures were captured between 2016 and 2022, consisting of 24,651 (82.7%) maintained on dual antiplatelet therapy (DAPT) and 5151 (17.3%) on alternative regimens. Patients maintained on DAPT were compared with those on alternative regimens consisting of any combination of single antiplatelet monotherapy and/or anticoagulation. On univariable analysis, patients on alternative medications were more likely to experience in-hospital death, ipsilateral stroke, any stroke, and transient ischemic attacks compared with patients in the DAPT group. The mortality rate was higher at 1 year in the alternative cohort (4.7% vs 7.0%, P <0.01). The use of alternate medication regimens was associated with increased odds of stroke and the composite outcome of in-hospital stroke/death compared with DAPT. There was also a significant association between alternative medication use and increased odds of in-hospital transient ischemic attack, immediate stent occlusion, and return to the operating room. At 1 year, there was no significant difference in the incidence of stroke between the 2 groups. However, the use of alternate regimens was associated with higher 1-year of mortality after multivariable adjustment. Patients not maintained on DAPT after TCAR experienced an increased risk of stroke and death in the perioperative and follow-up periods. Increased surgeon vigilance is required to ensure compliance with dual antiplatelets as recommended.

Fixed compared to mobile imaging arms for transcarotid artery revascularization.

Transcarotid artery revascularization (TCAR) is a new surgical option for carotid artery stenosis. While this procedure is optimally performed in hybrid operating rooms (OR), it is currently unclear whether it could be safely performed using portable, C-arm fluoroscopy with equivalent results. The aim of this study is to determine whether there are differences in intraoperative and perioperative outcomes stratified by imaging modality. A retrospective review of all TCAR procedures attempted within our health system was performed, capturing all cases between September 2017 and May 2022. Procedures were divided into 2 cohorts, based on whether they were performed in a hybrid OR or with portable, C-arm in a standard OR. Patient demographics, intraoperative results, and postoperative outcomes were compared using univariate strategies. A total of 503 patients were included for review, of which 422 were performed in a hybrid OR (84%) and 81 were performed using a portable C-arm (16%). Intraoperatively, an increased estimated blood loss (47.7 ± 54.7 vs 26.1 ± 26.9mLs, p < 0.01) and operative time was found in the cases performed in a hybrid OR. However, the fluoroscopy time was lower (4.0 ± 2.6 vs 5.2 ± 5.8min, p = 0.01) in the setting of advanced intraoperative imaging. Postoperatively, we found no differences with respect to myocardial infarction (0.2% vs. 0%, p > 0.99), stroke (2.4% vs. 2.5%, p = 0.96), or death (0.7% vs. 2.5%, p = 0.15) between groups. While there are some intraoperative variabilities between TCAR performed in hybrid versus standard ORs, postoperative outcomes are comparable. Therefore, the lack of a hybrid room should not be a deterrent to the adoption of TCAR.

A single-center experience of 30-day perioperative and one year clinical outcomes of transcarotid artery revascularization in 100 consecutive patients.

Transcarotid Artery Revascularization (TCAR) using the ENROUTE system (Silk Road) has been proposed as a safe and effective alternative to both carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TF-CAS). Two large registries (ROADSTER 1 and ROADSTER 2) have shown that TCAR has acceptable/low rates of perioperative stroke/death. This study will analyze the 30-day perioperative and 1-year clinical outcomes from a single-center. This is a retrospective analysis of prospectively collected data from SVS/VQI TCAR surveillance project (TSP) of 100 consecutive patients (102 TCAR procedures) done in our institution. These procedures were done for high-risk patients for CEA, which included anatomical (previous CEA, high cervical lesion, neck radiation, stoma, arch type, etc.), physiological (CHF, severe coronary artery disease, COPD on O2 therapy, etc.) and combined anatomical/physiological reasons. These procedures were done by vascular surgeons after receiving the appropriate training. The perioperative stroke, death, and MI rates were analyzed. Kaplan Meyer analysis was used to estimate rate of freedom from stroke/death and the incidence of ≥50% and ≥80% in-stent restenosis at 1year. 100 consecutive high-risk patients for CEA included: 38% anatomical, 44% physiological, and 18% combined anatomical and physiological reasons. The mean age was 72.5years (range 52-90years). Indications for TCAR were 34% for symptomatic lesions (TIA/stroke) and 66% for asymptomatic lesions. Mean ipsilateral treated stenosis was 80.4%. Contralateral ≥50% stenosis/occlusion was present in 31% of patients. Technical success rate was 100%. 92% had pre-stenting PTA and 26% had post-stenting PTA. The mean flow reversal time was 8.5min (range 3-26min). The 30-day perioperative stroke rate was 2.9% (1/67, 1.5% for asymptomatic patients), the stroke/death rate was 2.9%, and stroke/death and MI rate was 3.9% (4/102). Other perioperative complications included cranial nerve injury 3/102 (2.9%), carotid artery dissection (2%), and major hematoma (necessitated operation evacuation) (5.9%). Freedom from stroke rates and stroke/death rates at 1year were: 90% and 89%. Freedom from ≥50% and ≥80% in-stent restenosis rates at 1year were 82% and 90%, respectively. None of these restenosis were symptomatic except two (2/13). Freedom from reintervention rate at 1 year was 98%. Although the perioperative events were somewhat higher than what has been reported in previous registries, TCAR for patients who are high-risk for CEA has a low perioperative stroke and stroke/death rates with satisfactory outcome at 1year. Further long-term data is probably needed to verify long-term outcome.

Results associated with the health system-wide adoption of transcarotid revascularization

BackgroundIn the present report, we have detailed the results derived from the adoption of transcarotid artery revascularization (TCAR) at a large health system based in the United States. MethodsA retrospective review was performed of a prospectively maintained database capturing all carotid stents deployed using the ENROUTE neuroprotection device (Silk Road Medical, Sunnyvale, CA) and cerebral flow reversal. The demographics, intraoperative findings, and postoperative results were tabulated and reported. ResultsFrom September 2017 to December 2021, 429 TCAR procedures were attempted within the Memorial Hermann Health System. Preoperatively, all the patients were either asymptomatic with >70% stenosis (66.9%) or symptomatic with >50% stenosis (33.1%). The degree of stenosis was determined using computed tomography angiography and/or duplex ultrasound. We achieved a technical success rate of 99.1%, with the failures attributed to an inability to cross the lesion, an inability to track the stent, visualization of a flow-limiting dissection, and stent maldeployment for one patient each. During the 30-day perioperative period, nine strokes (2.3%) had occurred, three of which had occurred after discharge from the index operation and before the end of the 30-day period. No patient had experienced myocardial infarction. Five patients had died in the perioperative period. Three of the deaths were related to stroke, and two were attributed to cardiopulmonary events secondary to aspiration and likely pulmonary embolus. The mean follow-up after TCAR was 14.5 ± 12.0 months. During the follow-up period, two patients had required reintervention for in-stent stenosis. Ipsilateral to the implanted carotid stent, the overall (including perioperative) stroke incidence was 2.5%. Contralateral to the stent, the stroke incidence was 0.8%. The myocardial infarction rate was 0.8% during follow-up. Mortality in our study population was 5.1% during the follow-up period. ConclusionsAfter adoption of TCAR across the Memorial Hermann Health System, we found this procedure to be safe and efficacious with minimal perioperative risks comparable to the historically reported results associated with alternative carotid interventions.

Hemodynamic instability in the immediate postoperative setting after transcarotid artery revascularization.

Transcarotid artery revascularization (TCAR) is a relatively recent development in the management of carotid artery occlusive disease, the utilization of which is becoming more prevalent. This study aims to evaluate the timing, prevalence, and types of hemodynamic instability after TCAR. We performed a retrospective review of all TCAR procedures performed at two tertiary care academic medical centers within a single hospital system from 2017 through 2019. Demographics, comorbidities, preoperative patient factors, procedural details, and postoperative data were collected. Patients were assessed over 24hours postoperatively for stroke, death, myocardial infarction (MI), and hemodynamic instability at 3, 6, 9, 12, and 24hour intervals. Hemodynamic instability was defined as any vital sign abnormality which required pharmacological intervention with antihypertensive, vasopressor, and/or anti-arrhythmic agents. The incidence and timing of postoperative complications and hemodynamic instability were recorded. During the study period, 76 patients 80 TCAR procedures. Out of 80 procedures, 64 (80.0%) were receiving home antihypertensive medication and 28 (35.0%) were symptomatic lesions preoperatively. Intraoperatively, one patient (1.3%) received atropine, 26 (32.5%) received glycopyrrolate, 76 (95%) underwent predilatation, and 16 (20.0%) underwent postdilatation. Postoperatively, a total of 22 cases (27.5%) required medication for acute control of blood pressure or heart rate, which reached a peak of 19 patients (23.8%) within the first 3hours, and tapered to nine patients (11.3%) by the 24hour mark. A total of three patients (3.75%) required initiation of pharmacological management after the three-hour mark. Six patients (7.5%) underwent stroke code workup, 4 (5.0%) of whom were confirmed to have stroke on CT. Average time to neurologic event was 3.9hours. No patients experienced MI or death. Median ICU and hospital days for unstable patients were two and three, respectively, compared to one and one for stable patients. Hemodynamic instability is common after TCAR and reliably presents at or before postoperative hour 3. Hypo- followed by hyper-tension were the most common manifestations of hemodynamic instability. Regardless, unstable patients and stroke patients were more likely to require longer periods of time in the ICU and in the hospital overall. This may have implications for postoperative ICU resource management when deciding to transfer patients out of a monitored setting. Further study is required to establish relationships between pre- and intra-operative risk factors and outcomes such as hemodynamic instability and/or stroke. At present, one should proceed with careful evaluation of preoperative medications, strict management of postoperative hemodynamics, and clear communication among team members should all be employed to optimize outcomes.

Outcomes of early transcarotid artery revascularization versus carotid endarterectomy after acute neurologic events

ObjectiveCarotid revascularization within 14 days of a neurologic event has been recommended by society guidelines. Transcarotid artery revascularization (TCAR) carries the lowest overall stroke rate for any carotid artery stenting technique. However, the outcomes of TCAR within 14 days of a neurologic event have not been directly compared with those after carotid endarterectomy (CEA). MethodsWe compared the 30-day outcomes of symptomatic patients who had undergone TCAR and CEA within 14 days of a stroke or transient ischemic attack (TIA) from January 2016 to February 2020 using the Society for Vascular Surgery Vascular Quality Initiative carotid artery stenting and CEA databases. Propensity score matching was used to adjust for patient risk factors. The primary outcome was a composite of postoperative ipsilateral stroke, death, and myocardial infarction (MI). ResultsA total of 1281 symptomatic patients had undergone TCAR and 13,429 patients had undergone CEA within 14 days of a neurologic event. After 1:1 propensity matching, 728 matched pairs were included for analysis. The primary composite outcome of stroke, death, or MI was more frequent in the TCAR group (4.7% vs 2.6%; P = .04). This was driven by a higher rate of postoperative ipsilateral stroke in the TCAR group (3.8% vs 1.8%; P = .005). No differences were found between TCAR and CEA in terms of death (0.7% vs 0.8%; P = .8) or MI (0.8% vs 1%; P = .7). Although TCAR procedures were shorter (median, 69 minutes [interquartile range, 53-85 minutes]; vs median, 120 minutes [interquartile range, 93-150 minutes]; P < .001) and the postoperative length of stay was similar (2 days; P = .3) compared with CEA, the TCAR patients were more likely to be discharged to a facility other than home (26% vs 19%; P < .01). Performing TCAR within 48 hours of a stroke was an independent predictor of postoperative stoke or TIA (odds ratio, 5.4; 95% confidence interval, 1.8-16). This increased risk of postoperative stroke or TIA was not found when performing TCAR within 48 hours of a TIA. ConclusionsTCAR within 14 days of a neurologic event resulted in higher ipsilateral postoperative stroke rates compared with CEA, especially when performed within 48 hours after a stroke.

Institutional Experiences with Transfemoral Compared to Transcarotid Stenting

Transcarotid artery revascularization (TCAR) is a new surgical technique that is gaining popularity over the transfemoral method (TF-CAS) as the preferred strategy to deliver a carotid stent. This investigation was performed to evaluate the real-world perioperative and long-term outcomes of both techniques at the health system level. A retrospective review of prospectively maintained carotid revascularization databases were performed at 2 high-volume TCAR centers in the United States to extract consecutive TF-CAS and TCAR procedures. The characteristics and outcomes associated with these 2 modalities were compared at the preoperative and perioperative points by univariate methods. The Kaplan-Meier methodology was utilized to calculate the long-term stroke and death trends. From 2008-2021, 1,058 carotid stents were implanted at our institutions, consisting of 750 TCARs and 308 TF-CAS procedures. Patients undergoing TF-CAS were older (68.2±0.6 vs. 73.1±0.3years, P<0.01) and unhealthier by Charlson Comorbidity Index (4.9±0.1 vs. 5.5±0.1, P<0.01). Additionally, TF-CAS patients had more high-risk anatomic characteristics, such as restenosis after previous carotid surgery (27.0% vs. 9.5%, P<0.01), previous ipsilateral neck surgery (38.8% vs. 11.5%, P<0.01), irradiated ipsilateral field (20.4% vs. 4.5%, P<0.01), and a contralateral carotid occlusion (10.4% vs. 4.6%, P<0.01). The incidence of symptomatic lesions was the same (40.1% vs. 36.9%, P=0.35). Within the operating room, TCAR outperformed TF-CAS with respect to operative time (83.2±2.6 vs. 64.3±0.9min, P<0.01), radiation exposure (769.9±144.3 vs. 232.7±19.1mGys, P<0.01), fluoroscopic time (17.8±1.1 vs. 4.5±0.1min, P<0.01), and contrast volume (75.2±2.4 vs. 22.6±0.4mLs, P<0.01). In the 30-day perioperative period, ipsilateral stroke (2.8% vs. 2.3%, P=0.65), contralateral stroke (1.0% vs. 0.1%, P=0.07), and death (1.0% vs. 1.2%, P>0.99) were similar between modalities. None of these endpoints, including a composite of stroke and death (4.8% vs. 3.6%, P=0.38), reached statistical significance. Additionally, we found no differences with respect to stroke-free survival between modalities during follow-up by Kaplan-Meier analysis (P=0.30). In this combined experience from 2 large health systems, TCAR was associated with less intraoperative complexity, as measured by operative time, radiation exposure, and contrast volume. Although stroke and death seemed to be less frequent in patients undergoing transcervical stenting, this did not reach statistical significance.

Learning curve and proficiency metrics for transcarotid artery revascularization

BackgroundWhen introduced to a new procedure, physicians improve their performance and reduce their procedural adverse event rates rapidly during the initial cases and then improvement slows, signaling that proficiency has been achieved. Determining when they have acquired proficiency has important implications for procedural innovation, education, credentialing, and patient safety. We analyzed the worldwide experience with transcarotid artery revascularization (TCAR), a hybrid approach to carotid revascularization, to identify the (1) procedural performance measures associated with clinical and technical adverse events; (2) target levels of performance measures that minimize adverse event rates; and (3) number of TCAR cases needed to achieve the target levels for the performance measures. MethodsThe patient, lesion, and physician characteristics were collected for each TCAR procedure performed by each physician worldwide in an international quality assurance database. Four procedural performance measures were recorded for each procedure: flow-reversal time, fluoroscopy time, contrast volume, and total skin-to-skin time. Composite clinical adverse events (ie, transient ischemic attack, stroke, myocardial infarction, death) and composite technical adverse events (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, device failure), occurring within 24 hours were also recorded. Correlations between each performance measure and the clinical and technical adverse event rates were computed. The inflection points in the performance measures were identified at which no further improvements occurred in the adverse event rates. Finally, the minimum number of TCAR cases required to achieve the target performance measure levels was computed. ResultsA total of 18,240 procedures performed by 1273 physicians were analyzed. Of the 18,240 patients, 34.9% were women and 62.5% were asymptomatic. The flow-reversal time correlated with clinical adverse events adjusted for age, sex, and symptomatic status (R2 = 0.91; P < .0001) and adjusted technical adverse events (R2 = 0.86; P < .0001). The skin-to-skin time correlated with adjusted technical adverse events (R2 = 0.92; P < .0001). A reduction in flow-reversal times to <13.1 minutes and the skin-to-skin time to <81 minutes did not translate into further improvements in the adverse event rates. A minimum of 26 TCAR cases was required to achieve the target flow-reversal time, and a minimum of 15 cases was required to achieve the target skin-to-skin time. ConclusionsThe flow-reversal time and skin-to-skin time are appropriate performance measures for establishing the level of expertise of physicians as they acquire skills to perform TCAR. A target time of ≤13.1 minutes for flow-reversal and 81 minutes for skin-to-skin time minimized the adverse event rates. Familiarity with the steps involved in performing TCAR was achieved after ≥15 cases, and minimizing clinical adverse events occurred after ≥26 cases.

Abstract 12941: In-Hospital Outcomes Among Diabetics Undergoing Transcarotid Artery Revascularization for Carotid Artery Stenosis

Introduction: Transcarotid artery revascularization (TCAR) is a novel procedure to intervene on clinically significant carotid artery stenosis. Periprocedural rates of stroke have remained exceedingly low in clinical trials (&lt;1.5%). Diabetics are known to have elevated risk of periprocedural adverse events with both carotid endarterectomy and carotid artery stenting. TCAR may offer lower periprocedural rates of cerebrovascular accident given its novel flow reversal technique. However, outcomes among diabetics undergoing TCAR remain unknown. We sought to determine periprocedural cardiovascular and cerebrovascular events (MACCE) among diabetics undergoing the TCAR procedure in a large national database. Methods: The Vascular Quality Initiative database was queried for all TCAR procedures performed from January 2012 to March 2021. Baseline demographic information as well as periprocedural outcomes were obtained. In cases in which a patient had multiple procedures, only the most recent procedure was evaluated. Results: A total of 19,341 patients (median age 74 (IQR 67-80), 63.7% male and 90.3% white) underwent the TCAR procedure. Of this n=7,427 (38.4%) were diabetics. Compared to non-diabetics, the diabetic cohort had a higher risk of stroke (1.7% vs 1.3%, p=.02), transient ischemic attack (0.7% vs 0.4% p =.027), and myocardial infarction (0.7% vs 0.5% p=.064). Death remained a rare outcome, with diabetics having 0.5% periprocedural mortality vs 0.4% among non-diabetics (p=.096). Conclusions: TCAR is a safe revascularization method for significant carotid artery stenosis with an elevated risk of periprocedural MACCE in diabetics compared to non-diabetics. Further study is needed to define optimal patient selection for this novel and less-invasive management strategy for carotid artery disease.

Anesthetic Considerations for Transcarotid Artery Revascularization: Experience and Review of Forty Cases From a Single Medical Center.

Transcarotid artery revascularization (TCAR) procedure is a novel hybrid surgical modality in treating carotid stenosis. Understanding the various steps of the TCAR and the unique challenges involved in the anesthetic management is essential for the successful conduct of anesthesia. In this article, we discuss the overview of the key issues relevant to the anesthetic management and strategies from our experience. We present the data on anesthetic management and outcomes of 40 patients who underwent TCAR procedure at our institute between June 2018 and February 2020. Electronic medical records were retrospectively reviewed and relevant demographic, clinical, and laboratory data were collected. All our patients had general anesthesia with an endotracheal tube utilizing standard American Society of Anesthesiology (ASA) monitoring along with intra-arterial blood pressure monitoring and cerebral oximetry.The mean age of our patients was 73.6 ± 7.58 years. Fifteen (37.5 %) patients had significant co-morbidities, thus classified as ASA 4 and 10 (25%) patients were on at least three antihypertensives (beta-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, loop diuretics, thiazides). Thirty-four (85%) patients were considered to have symptomatic carotid stenosis which was the predominant indication for the TCAR procedure. Patients who had episodes of transient ischemic attack (TIA) or a cerebrovascular accident (CVA) documented by a computerized tomography (CT) scan of the brain and/or residual weakness are considered symptomatic. Thirty-six (90%) of our patients received a bolus dose of 0.2 - 0.4 mg of glycopyrrolate for maintaining heart rate of around 70 beats per minute (BPM) and 38 (95%) received phenylephrine infusion during the carotid clamp to maintain blood pressure between 140 and 160 mm Hg systolic or at patients’ baseline. Twenty-one (52.5%) patients needed antihypertensives such as hydralazine ( 10-20 mg) or beta-blockers such as labetalol (10-20 mg) at the time of emergence from anesthesia to mitigate hemodynamic response during extubation. The mean blood loss was 74 ml ± 33.19 ml, and none of our patients received blood transfusion during the perioperative period. The mean duration of anesthesia was 202.6 ± 27.85 minutes, and the mean length of hospital stay was 1.5 ± 0.97 days.A thorough preoperative examination with specific attention to the preoperative neurological deficits and cardiopulmonary reserve is important for the meticulous management of intraoperative hemodynamics. Intraoperative administration of glycopyrrolate and the use of vasopressors to maintain optimal hemodynamics to ensure cerebral perfusion during the perioperative period should be considered. The anesthetic goals of carotid revascularization (TCAR) are perioperative hemodynamic stability and early evaluation of neurological status in the immediate postoperative period.

Duplex Ultrasound Surveillance after Transcarotid Artery Revascularization (TCAR) in Clinical Practice

To propose a protocol for the routine clinical use of duplex ultrasound (DUS) assessment after transcarotid artery revascularization (TCAR) procedures, with its specific point of vascular access, based on DUS data from routine clinical practice. DUS data were retrospectively collected at 2 centers from a total of 97 patients who underwent a TCAR procedure with at least 30-day and up to 12-month follow-up. Peak systolic velocity (PSV), end diastolic velocity (EDV), and the internal carotid artery (ICA)/common carotid artery (CCA) PSV ratio were collected at baseline (≤30days after the procedure) and compared with subsequent measurements. Baseline data were established within 30days after the procedure. There were no access site stenoses, pseudoaneurysms, or dissections detected in follow-up. Average hemodynamics measurements at 12months after the procedure (36% of patients reached this time point to date) were PSV 167±153cm/sec, EDV 51±55cm/sec, and ICA/CCA PSV 2.3±1.9. Five patients (5.2%) exhibited velocities indicative of ≥80% in-stent restenosis (ISR) at 12months after the procedure. Two patients (2.1%) underwent repeat intervention for ISR based on high velocities and before significant clinical consequence. The other 3 patients (3.1%) were asymptomatic and are being managed medically and monitored for neurological symptoms. One intraprocedural stroke (1.0% of total treated) was observed. This protocol not only illustrates the utility of using the CCA for the arterial access sheath for carotid stenting, but also successfully identifies patients with clinically significant restenosis >80%-99%. A surveillance regimen of baseline at ≤30days after the procedure, followed by assessment at 6 and 12months, and yearly thereafter appears to be a safe and effective protocol, based on the data available to date. A PSV >340cm/sec and ICA/CCA ratio >4.15 is consistent with an 80-99% restenosis after TCAR. Although a small number, this study serves as a starting point for those who perform TCAR to specifically look at the CCA access site to rule out these potential pitfalls which did occur in the early trials.

Outcomes of Transcarotid Artery Revascularization (TCAR) in Octogenarians and Older

Carotid revascularization, both endarterectomy (CEA) and transfemoral carotid artery stenting (TFCAS), are associated with an increased risk of adverse outcomes in patients aged ≥80years. Transcarotid artery revascularization (TCAR) is a technique that combines surgical principles of neuroprotection with less invasive endovascular techniques to treat severe carotid stenosis. Data from a recent registry study comparing TCAR with that of CEA and TFCAS demonstrated no significant difference in outcomes between TCAR and CEA in patients aged ≥80years, and a significant reduction in stroke and composite outcomes between TCAR and TFCAS in patients aged ≥80years. To add to these studies, a more in-depth analysis of demographic, procedural, and outcome factors is warranted for elderly patients aged ≥80years undergoing TCAR. At our center, with a large volume of elderly patients based on local demographics, we expect there will be no significant effect of age on outcome measures between patients aged <80 years and those aged ≥80years. Data were collected retrospectively for patients undergoing TCAR for symptomatic (≥50%) or asymptomatic (≥80%) extracranial carotid artery stenosis. Primary endpoints were the incidence of ipsilateral cerebrovascular ischemic event (stroke or transient ischemic attack), myocardial infarction (MI), cranial nerve injury, and death through 30days after the procedure. Secondary endpoints were postoperative length of hospital stay (LOS), procedure time, carotid artery clamp/flow reversal time, and fluoroscopy time. Subgroup analyses were performed to examine the effect of inpatient/outpatient status, carotid symptomatology, and type of anesthesia on secondary outcomes. Ninety-seven TCAR procedures were performed at our institution during the study period, of which 43 (44%) were on patients aged ≥80years. Technical success was achieved in all cases, with no incidence of cerebrovascular ischemic event, MI, cranial nerve injury, or mortality through 30days after procedure. In patients aged ≥80years, the mean procedure time was 47±12min, clamp/flow reversal time was 4.7±1.1min, fluoroscopy time was 4.1±1.6min, and median LOS was 2.0±1.0days. Procedure time, clamp/flow reversal time, and fluoroscopy time were not significantly different between the age groups. However, there was a significant difference in the LOS, with patients aged <80years demonstrating a median LOS of 1.0±0.0days (P = <0.001). Our experience with TCAR confirms that it can be performed successfully in both symptomatic and asymptomatic high-risk elderly patients, with our series finding no incidence of perioperative cerebral ischemic event, MI, or death.

Outcomes and strategy of tailored antiplatelet therapy with ticagrelor in patients undergoing transcarotid artery revascularization

ObjectiveAntiplatelet drug resistance is associated with periprocedural ischemic complications in patients undergoing intravascular stent implantation. Nonresponders are subject to increased risk of stent thrombosis and in-stent stenosis, and high on-treatment platelet reactivity (HTPR) is present in up to 44% of patients taking clopidogrel, a widely used component of dual antiplatelet therapy (DAPT). Evidence points to ticagrelor as a viable alternative to overcome HTPR on clopidogrel. Studies have shown fewer thromboembolic events with ticagrelor therapy; however, results on bleeding risk are mixed, and its safety and efficacy in hybrid operative techniques have yet to be established. Transcarotid artery revascularization (TCAR) is a hybrid procedure to treat severe carotid stenosis. The objective of this study was to establish the safety and efficacy of ticagrelor as part of DAPT in patients undergoing TCAR and to develop a protocol to ensure adequate antithrombotic protection throughout the operative course. MethodsData were collected retrospectively for patients undergoing TCAR on DAPT of aspirin and ticagrelor for symptomatic (≥50%) or asymptomatic (≥80%) carotid stenosis. Preoperative platelet reactivity was determined using Thromboelastography with Platelet Mapping (Haemonetics Corporation, Braintree, Mass), with adequate platelet reactivity defined as maximal amplitude produced by adenosine diphosphate <50 mm. The primary safety end point was 30-day major bleeding event rate. Primary efficacy end points were 30-day incidence of ipsilateral cerebrovascular ischemic event (stroke or transient ischemic attack), myocardial infarction, and death. Secondary end points were postoperative length of hospital stay, procedure time, and clamp/flow reversal time. ResultsSixty-seven TCAR procedures with patients receiving periprocedural DAPT of ticagrelor and aspirin were performed during the study period. Patients had an average age of 79 years, and 28 (42%) were symptomatic. The mean procedure time was 45.8 ± 9.2 minutes, with a mean clamp/flow reversal time of 4.8 ± 1.5 minutes, and mean postoperative length of hospital stay of 3.1 ± 2.2 days for inpatients and 1.3 ± 0.8 days for outpatients. Technical success was achieved in all cases, with no 30-day major bleeding events and no occurrence of ipsilateral cerebrovascular ischemic event, myocardial infarction, or death. ConclusionsInitial experience with ticagrelor as part of DAPT in patients undergoing TCAR demonstrated its safety and efficacy in both symptomatic and asymptomatic disease. No bleeding events or thromboembolic complications occurred. Furthermore, a protocol to administer ticagrelor to assay for HTPR on ticagrelor and consequent medication and patient management is proposed. Ticagrelor may represent a safe and effective alternative to overcome clopidogrel nonresponsiveness in DAPT regimens for TCAR.

Technical tips for success in transcarotid artery revascularization

Transcarotid artery revascularization is a minimally invasive technique performed by vascular surgeons for the management of carotid artery stenosis via direct access of the common carotid artery and stenting of the common and internal carotid artery atherosclerotic stenosis. Unlike the transfemoral approach for carotid artery stent angioplasty, the transcarotid artery revascularization procedure allows cerebral protection from embolization without manipulation of the internal carotid artery stenotic lesion via the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical, Sunnyvale, CA). The ENROUTE reverse flow cerebral protection affords the opportunity to predilate carotid artery lesions with relative impunity before stent deployment. Our technique of transcarotid artery revascularization is detailed in this report of 70 patients (112 procedures) with <1% perioperative neurologic morbidity and documents clinical and hemodynamic (duplex ultrasound testing) success at more than 6 months’ follow-up.