Learning curve and proficiency of transcarotid artery revascularization compared to transfemoral carotid artery stenting

Next-generation transcarotid artery revascularization: TransCarotid flOw Reversal Cerebral Protection And CGUARD MicroNET-Covered Embolic Prevention Stent System To Reduce Strokes - TOPGUARD Study

BACKGROUND

Stent-assisted carotid artery revascularization employing surgical cutdown for transcervical access and dynamic flow reversal (TCAR) is gaining popularity. TCAR, despite maximized intra-procedural cerebral protection, shows a marked excess of 30-day neurologic complications in symptomatic vs. asymptomatic stenoses. The TCAR conventional single-layer stent (free-cell area 5.89mm2) inability to seal embologenic lesions may be particularly relevant after the flow reversal neuroprotection is terminated.

METHODS

We evaluated peri-procedural and 30-day major adverse cerebral and cardiac events (MACCE) of TCAR (ENROUTE, SilkRoad Medical) paired with MicroNET-covered neuroprotective stent (CGuard, InspireMD) in consecutive patients at elevated risk of complications with transfemoral/transradial filter-protected stenting (increased lesion-related and/or access-related risk). CGuard (MicroNET free cell area ≈0.02-0.03 mm2) has level-1 evidence for reducing intra- and abolishing post-procedural lesion-related cerebral embolism.

RESULTS

One hundred and six increased-risk patients (age 72 [61-76] years, median [Q1-Q3]; 60.4% symptomatic, 49.1% diabetic, 36.8% women, 61.3% left-sided index lesion) were enrolled in three vascular surgery centers. Angiographic stenosis severity was 81 (75-91)%, lesion length 21 (15-26)mm, increased-risk lesional characteristics 87.7%. Study stent use was 100% (no other stent types). 74.5% lesions were predilated; post-dilatation rate was 90.6%. Flow reversal duration was 8 (5-11)min. One stroke (0.9%) occurred in an asymptomatic patient prior to establishing neuroprotection (index lesion disruption with the sheath insertion wire); there were no other peri-procedural MACCE. No further adverse events occurred by 30-days. 30-day stent patency was 100% with normal velocities and absence of any in-stent material by Duplex Doppler.

CONCLUSIONS

Despite a high proportion of increased-risk lesions and clinically symptomatic patients in this study, TCAR employing the MicroNET-covered anti-embolic stent showed 30-day MACCE rate <1%. This suggests a clinical role for combining maximized intra-procedural prevention of cerebral embolism by dynamic flow reversal with anti-embolic stent prevention of peri- and post-procedural cerebral embolism (TOPGUARD NCT04547387).

Trans-Carotid Artery Revascularization Versus Carotid Endarterectomy in Patients With Carotid Artery Disease: Systematic Review and Meta-analysis of 30-day Outcomes

This systematic review and meta-analysis compared trans-carotid artery revascularization (TCAR) as an alternative approach to carotid endarterectomy (CEA) in patients with carotid artery disease. An electronic search was conducted using PubMed, Scopus, and Cochrane databases including comparative studies with patients who underwent either TCAR or CEA. This meta-analysis is according to the recommendations of the PRISMA statement. Eight studies met our eligibility criteria, incorporating 7,606 and 7,048 patients in the TCAR and CEA groups, respectively. Thirty-day mortality (odds ratio [OR]: 0.94, 95% confidence interval [CI]: 0.56-1.56, P = .81) and stroke (OR: 0.92, 95%CI 0.70-1.22, P = .57) were similar between the two groups, with low heterogeneity. The odds of myocardial infarction (OR: 1.79, 95% CI: 1.18-2.71, P = .01) and cranial nerve injury were significantly higher in patients undergoing CEA compared with TCAR (OR: 4.11, 95% CI: 2.59-6.51, P < .001). The subgroup analysis according to symptomatic pre-intervention status revealed no statistically significant difference regarding 30-day mortality (symptomatic OR: 0.91, 95% CI: 0.40-2.07, P = .82, asymptomatic OR: 0.93, 95% CI: 0.46-1.86, P = .83) and stroke (symptomatic OR: 0.88, 95% CI:0.47-1.64, P = .68, asymptomatic OR: 0.93, 95% CI: 0.64-1.35, P = .70). TCAR offers an alternative treatment for patients with carotid artery stenosis with comparable to CEA mortality and stroke rates during a 30-day post-operative period.

Prospective evaluation of acute cerebral injury by DW-MRI following transcarotid artery revascularization using a double-layer micromesh stent

BACKGROUND

Transcervical carotid artery revascularization (TCAR) has demonstrated a low overall stroke rate in carotid artery stenting (CAS). Furthermore, the use of a double-layer micromesh stent is expected to reduce embolization and plaque prolapse. The combination of TCAR and the double layer stent may lead to improved results compared to previously reported outcomes. The objective of this study is to present the findings of a prospective study including patients treated with the Roadsaver stent and TCAR.

METHODS

Between January 2017 and May 2022, 85 patients were enrolled. Every patient underwent TCAR with the Roadsaver stent. As per our protocol, a neurological examination and an ultrasound were performed within 24 hours before and after the procedure, and again 30 days after. A diffusion-weighted magnetic resonance imaging (DW-MRI) was conducted 24 hours before the procedure and 48-72 hours after the procedure. The primary endpoint was the detection of new ischemic lesions on postoperative DW-MRI. The secondary endpoint was a composite of all strokes, death, and myocardial infarction within 30 days.

RESULTS

Sixty-four patients (75.29%) were symptomatic, out of which 25 were treated within 14 days of the onset of the symptoms. Pre and postprocedural DW-MRI were performed in 83 patients. Postprocedural lesions were found in nine patients (10.84%). There were no strokes or death within 30 days, but two patients experienced a myocardial infarction.

CONCLUSIONS

Our study suggests that the use of TCAR and the Roadsaver stent could be a safe alternative to carotid endarterectomy because it entails a low incidence of cerebral embolization, even in recently symptomatic and elderly patients.

Perioperative Outcomes in Transcarotid Artery Revascularization Versus Carotid Endarterectomy or Stenting Nationwide

BACKGROUND AND OBJECTIVES

Transcarotid artery revascularization (TCAR) is a newer treatment for carotid stenosis where the carotid artery is accessed directly in the neck for stenting. It is less invasive than carotid endarterectomy (CEA) and has less embolic potential than carotid artery stenting (CAS), but population-level utilization of TCAR and outcomes are currently unknown. Our study compares outcomes of TCAR with those of CEA and CAS.

METHODS

The National Inpatient Database was used for years 2015 to 2019. A multivariate logistic regression model was used to compare CEA, CAS, and TCAR outcomes with age, sex, race, hospital teaching status, symptomatic carotid disease status, side of procedure, intraoperative monitoring, and the weighted Elixhauser comorbidity score as covariates.

RESULTS

TCAR comprised 0.69% of these procedures in 2016, rising to 1.35% in 2019. The inpatient rates of death, stroke, and myocardial infarction for TCAR were 0.63% (95% confidence interval: 0.36%, 1.06%), 0.42% (0.21%, 0.80%), and 1.46% (1.04%, 2.05%), respectively. Compared with CEA, TCAR had statistically insignificant difference odds of death, odds ratio (95% CI) for stroke was 0.47 (0.25, 0.87), and for myocardial infarction, it was 0.66 (0.37, 0.94). Compared with CAS, for TCAR, the odds ratio for death was 0.41 (0.24, 0.71), and for stroke, it was 0.48 (0.26, 0.91).

CONCLUSION

TCAR is underutilized relative to other revascularization techniques yet has favorable outcomes compared with CEA and CAS. TCAR may be preferred to CAS in patients not surgical candidates for CEA and has a less invasive possibility for those eligible for CEA.

Comparison of the Clinical Outcome of Carotid Artery Stenting Between Institutions With a Treatment Strategy Based on Risk Factors and Those With First-Line Treatment

PURPOSE

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are recommended based on certain risk factors. The volume of an institution's treatment experience may be associated with good clinical outcomes. There is a dilemma between the treatment strategy based on risk factors and the experience volume. Therefore, we investigated the clinical outcomes of CAS performed at institutions that selected the treatment strategy based on risk factors and those that performed CAS at the first-line treatment.

MATERIALS AND METHODS

Patients who underwent CAS at 5 institutions were included in this retrospective case-control study. We defined CEA/CAS institutions as those that selected the treatment option based on risk factors, and CAS-first institutions as those that performed CAS as the first-line treatment. We investigated cases of ischemic stroke, hemorrhagic stroke, myocardial infarction, and deaths within 30 days of the intervention between the CEA/CAS- and CAS-first institution groups. One-to-one propensity score matching was performed to compare rates of ischemic and hemorrhagic strokes within 30 days of the intervention.

RESULTS

A total of 239 and 302 patients underwent CAS at the CEA/CAS institutions and CAS-first institutions, respectively; ischemic stroke occurred in 12 (5.0%) and 7 patients (2.3%), respectively (p=0.09). No differences in major ischemic strokes (0.8% vs 1.3%; p=0.59), hemorrhagic strokes (0.4% vs 0.3%; p=0.87), or deaths (0.0% vs 0.7%; p=0.21) were observed. Myocardial infarction did not occur in either group. Propensity score analysis showed that ischemic stroke (odds ratio: 1.845, 95% confidence interval: 0.601-5.668, p=0.28) and hemorrhagic stroke (odds ratio: 1.000, 95% confidence interval: 0.0061-16.418, p=1.00) were not significantly associated with either institution group.

CONCLUSIONS

The CAS-specific treatment strategies for CAS can achieve the same level of outcomes as the treatment strategy based on risk factors. The CAS performed based on risk factors in CEA/CAS institutions and the treatment of more than 30 patients/year/institution in CAS-first institutions were associated with good clinical outcomes.

What Is the Role of Transcarotid Artery Revascularization?

Carotid endarterectomy (CEA) is the gold-standard method of carotid revascularization in symptomatic patients with ≥50% and in asymptomatic patients with ≥70% stenosis. Transfemoral carotid artery stenting (TFCAS) has been associated with higher perioperative stroke rates compared to CEA in several studies. On the other hand, transcarotid artery revascularization (TCAR) has outperformed TFCAS in patients who are considered high risk for surgery. There is increasing data that supports TCAR as a safe and efficient technique with outcomes similar to those of CEA, but additional level-one studies are necessary to evaluate the long-term outcomes of TCAR in high- and standard-risk patients.

A Scoping Review of Simulation-Based Training Paradigms for Carotid Artery Endarterectomy and Carotid Artery Stenting

BACKGROUND

Surgical simulation has come to the forefront to enhance the training of residents. The aim of our scoping review is to analyze the available simulation-based carotid revascularization techniques, including carotid endarterectomy (CEA) and carotid artery stenting (CAS) and suggest critical steps for evaluating competency in a standardized fashion.

METHODS

A scoping review of all reports on simulation-based carotid revascularization techniques including CEA and CAS was performed in PubMed/MEDLINE, Scopus, Embase, Cochrane, Science Citation Index Expanded, Emerging Sources Citation Index, and Epistemonikos databases. Data were collected according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The English language literature was searched from January 1, 2000 to January 9, 2022. The outcomes evaluated included measures of assessment of operator performance.

RESULTS

Five CEA and 11 CAS manuscripts were included in this review. The methods of assessments employed by these studies to judge performance were comparable. The 5 CEA studies sought to validate and demonstrate improved performance with training or distinguish surgeons by their experience level, either through assessing operative performance or end-product results. The 11 CAS studies used 1 of 2 types of commercial simulators and focused on determining the efficacy of simulators as teaching tools. By examining the steps of the procedure associated with preventable perioperative complications, it provides a reasonable framework for determining which elements of the procedure should be emphasized most. Furthermore, using potential errors as a basis for assessment of competency could reliably distinguish operators based on level of experience.

CONCLUSIONS

Competency-based simulation training is becoming more relevant as our surgical training paradigm shifts with the increased scrutiny within training programs of work-hour regulations and the need to develop a curriculum to assess our trainees' ability to perform specific operations competently during their stipulated training period. Our review has given us an insight into the current efforts in this space regarding 2 specific procedures that are key for all vascular surgeons to master. Although many competency-based modules are available, there is a lack of standardization in the grading/rating system of what surgeons consider vital steps of each procedure to assess these simulation-based modules. Therefore, the next steps of curriculum development should be based on standardization efforts for the different protocols available.

Transcarotid Arterial Revascularization Adoption Should not Be Hindered by a Concern for a Long Learning Curve

BACKGROUND

Transcarotid arterial revascularization (TCAR) offers a novel technique for carotid artery stenting (CAS) that provides flow reversal in the carotid artery and avoids aortic arch manipulation, thus, potentially lowering ipsilateral and contralateral periprocedural stroke rates. As a new technology, adoption may be limited by concern for learning a new technique. This study seeks to examine the number of cases needed for a surgeon to reach technical proficiency.

METHODS

Retrospective analysis was performed using a prospectively collected database of all TCAR procedures performed in a tertiary health care system between 2016 and 2020. Patient demographics and anatomic characteristics were collected. Intraoperative variables and perioperative outcomes were examined. These variables were collated into groups for the first 4 procedures, procedures 5-8, and after 8. Independent Samples t test, 1-way ANOVA, and logarithmic regression were used to statistically analyze the data.

RESULTS

One-hundred and eighty-seven TCARs were performed by 14 surgeons. One hundred and twenty-two (65%) were male, 59 (32%) were older than 75 years, and 83 (44%) were symptomatic. The most common indications were high-lesions in 87 patients (47%) and recurrent stenosis after CEA in 37 patients (20%). Significant differences were found between the first and second groups of 4 cases when comparing mean operative time (71 vs. 58 min; P = 0.001) and flow reversal time (10.8 vs. 7.9 min; P= 0.004). similar significant differences were found between the first and third groups of 4 cases but not between the second and third groups. There was a reduction in contrast usage and fluoroscopy time after the first 4 cases, however, this did not reach statistical significance. There was no ipsilateral perioperative strokes. One patient had a contralateral stroke on postoperative day 2 due to intracranial atherosclerosis, and there was one perioperative mortality that occurred on postoperative day 3 after discharge.

CONCLUSIONS

Procedural and flow reversal times significantly shorten after 4 TCAR procedures are performed. Other metrics, such as fluoroscopy time and contrast usage, are also decreased. Complications, in general, are minimal. Proficiency in TCAR, as measured by these metrics, is met after performing only 4 procedures.