Near-infrared spectroscopy as a predictor of cerebral ischaemia during carotid endarterectomy in awake patients

Objectives

The aim of our study was to evaluate the near-infrared spectroscopy monitoring system to detect cerebral ischaemia, find indications for selective shunting during carotid endarterectomy and compare it with an internal carotid artery stump pressure monitoring technique in patients operated under local anaesthesia.

Methods

During January 2015 and November 2018, 131 patients undergoing carotid endarterectomy under local anaesthesia were prospectively included in the study. Near-infrared spectroscopy as intraoperative monitoring was applied and compared with stump pressure.

Results

Carotid endarterectomy was performed successfully in 106 patients operated under local anaesthesia. Meanwhile, 25 patients developed neurological changes (motor or consciousness impairment, weakness of extremities, cognitive decline) during clamping, and all of them received a shunt. ΔrSO2, stump pressure and rSO2 (–11 ± 8%, 31 ± 6mmHg, 58 ± 11) values were smaller in the group of shunted subjects versus non-shunted group subjects (–2 ± 5%, 61 ± 17 mmHg, 64 ± 8) after 1 min of internal carotid artery clamping ( p < 0.05). Statistical analysis showed a sensitivity of 90% (95% CI: 0.85–0.95) and a specificity of 70% (95% CI: 0.62–0.78) for a ≥10% drop in ΔrSO2 to predict ischaemia symptoms during carotid clamping. Using stump pressure with a cut-off value of ≤40 mmHg for predicting symptoms, the sensitivity was 82% and specificity 54%.

Conclusions

Near-infrared spectroscopy is a suitable non-invasive cerebral oxygenation monitoring method during carotid endarterectomy. A 10% decrease of ΔrSO2 had a good correlation with clinical cerebral ischaemia signs and matched well with the stump pressure cut-off value of ≤40 mmHg. There is a possibility of near-infrared spectroscopy to replace stump pressure in cerebral oxygenation monitoring during carotid endarterectomy. However, we need larger prospective multicentre studies to identify the optimal threshold for shunt requirement.

Outcomes of simultaneous carotid endarterectomy and coronary artery bypass grafting: A single centre experience

OBJECTIVE

Stroke following a coronary artery bypass surgery is a well-known complication often predisposed by carotid artery disease. Perioperative risk of stroke after on-pump cardiac surgery can overall affect 2% of patients. Patients with 80-99% unilateral carotid artery stenosis carry a 4% risk of stroke. Significant carotid artery stenosis is present in 3-10% of patients who are candidates for coronary artery bypass grafting (CABG). Those patients might be considered for either simultaneous or staged carotid endarterectomy and CABG to reduce the risk of stroke and death. The purpose of this study was to evaluate preoperative and intraoperative risk factors for myocardial infarction (MI), stroke and death and assess complications occurring during the early postoperative period after simultaneous CABG/CAE procedure.

METHODS

A single centre retrospective analysis of 134 patients from 2015 to 2019 who underwent simultaneous CABG/CEA was performed. At the same period, a total of 2827 CABG were performed, of which 4.7% were simultaneous interventions. We excluded staged CEA/CABG procedures, off-pump CABG and urgent CABG patients. All patients included in the study met the criteria for elective CABG for triple-vessel or left main trunk symptomatic coronary artery disease (CAD) with asymptomatic >70% carotid stenosis or symptomatic ipsilateral >50% carotid stenosis regardless of the degree of contralateral carotid artery stenosis. Patient demographics, comorbidities and operative details were reviewed. The primary endpoint was to assess the intraoperative and 30-day risk of stroke and death after simultaneous CEA/CABG procedure.

RESULTS

Simultaneous CEA/CABG is effective procedure that can be performed in high-risk symptomatic patients with acceptable results. Predictors of postoperative stroke were smoking (P = 0.011), history of MI (P = 0.046), history of CABG (P = 0.013), and history of stroke/TIA (P = 0.005). Significant risk factors for adverse major postoperative complications after simultaneous CEA/CABG procedure were cardiac arrhythmia (AF or AFL) (P = 0.045), previous MI (P < 0.001), and smoking (P = 0.001).

CONCLUSIONS

Synchronous CEA/CABG procedure can be performed with acceptable results in patients having a high risk of stroke, septuagenarians and older.

Assessment of atherosclerotic plaque morphology using contrast-enhanced ultrasound and its impact on primary cardiovascular events following simultaneous carotid endarterectomy and coronary artery bypass grafting

OBJECTIVE

The incidence of stroke after on-pump cardiac surgery during the perioperative period can affect up to 2% of patients, and is frequently linked to carotid artery disease. Notably, in patients with significant unilateral carotid artery stenosis of 80%-99%, the risk of stroke reaches 4%. Among individuals undergoing coronary artery bypass grafting (CABG), 3% to 10% exhibit significant carotid artery stenosis. To mitigate the risk of stroke and mortality, patients can undergo either simultaneous or staged carotid endarterectomy and CABG. The aim of this study was to assess whether early postoperative complications, including stroke, following simultaneous CABG/CAE procedures, correlate with morphological attributes of carotid plaque, assessed via contrast-enhanced ultrasound.

METHODS

A single centre retrospective analysis was performed including 62 patients who underwent simultaneous CABG/CEA between 2019 and 2022. Our study excluded patients who underwent staged carotid endarterectomy and CABG procedures, off-pump CABG, or those necessitating urgent CABG. Our analysis focused on patients meeting elective CABG criteria, diagnosed with symptomatic triple-vessel or left main trunk coronary artery disease (CAD), alongside asymptomatic carotid stenosis (a. carotis internae) exceeding 70% or symptomatic ipsilateral carotid stenosis surpassing 50%. The extent of contralateral carotid artery stenosis was not taken into account. Prior to the CEA/CABG procedure, each patient underwent contrast-enhanced ultrasound to assess atherosclerotic lesions, which were classified using Nakamura et al.'s classification. Among the patients, 37.1% exhibited no neovascularisation within the atherosclerotic plaque, 56.5% showed insignificant neovascularisation, and 6.5% displayed notable neovascularization within the plaque. Our study aimed to establish a connection between the degree of plaque vascularisation identified through contrast-enhanced ultrasound and subsequent postoperative complications.

RESULTS

Upon evaluating postoperative complications occurring within 30 days after the surgery and the plaque morphology identified through contrast-enhanced ultrasound, a statistically significant correlation was observed between a higher grade of plaque vascularisation and the occurrence of ischaemic stroke (r = 0.329, p = .008). Monte Carlo calculations of the Chi-square test indicated a significant association between a higher grade of plaque vascularisation and the presence of peripheral artery disease (χ2 = 15.175, lls = 2, p = .003).

CONCLUSION

Within 30 days of surgery, a significant correlation exists between the occurrence of ischaemic stroke following carotid endarterectomy subsequent to CABG and the presence of a higher grade plaque vascularisation as identified by contrast-enhanced ultrasound.

Assessment of Plaque Characteristics by Contrast-Enhanced Ultrasound and Stent Restenosis following Carotid Artery Stenting: A Retrospective Study

Background and objective: carotid artery stenosis contributes significantly to ischemic strokes, with management options including carotid endarterectomy (CEA) and carotid artery stenting (CAS) ischemic stroke risk can be reduced. Controversies persist regarding their efficacy and factors influencing complications, and understanding the relationship between atherosclerotic plaque characteristics and stent restenosis after CAS is crucial. Methods: we conducted a retrospective study involving 221 patients who underwent CAS for symptomatic or asymptomatic carotid artery stenosis. Comprehensive assessments of plaque morphology were performed using contrast-enhanced ultrasound (CEUS) before CAS. Patient demographics, including smoking status and diabetes, were also recorded. Stent restenosis was diagnosed using various imaging modalities, including ultrasound, angiography, and digital subtraction angiography (DSA). Results: plaque analysis using CEUS revealed a significant association between plaque grade and restenosis incidence (p < 0.001), particularly with grade 0 (11.1%) and grade 2 plaques (66.7%). Smoking was notably associated with plaque vascularization and restenosis (p < 0.001), while diabetes did not significantly impact plaque characteristics or restenosis risk (p > 0.05). The mean duration of restenosis was 17.67 months. Stenting was the most frequent treatment modality for restenosis (70.6%). However, no significant relationship was found between restenosis type and plaque morphology (p = 0.268). Furthermore, while no clear relationship was observed between plaque morphology and the type of restenosis, our findings underscored the importance of plaque characterization in predicting post-CAS outcomes. Conclusions: this study highlights the utility of CEUS in predicting stent restenosis following CAS. There was a significant association between stent restenosis within 12-24 months after the carotid stenting procedure and an elevated grade of plaque vascularization. Moreover, one of the main factors possibly determining the grade of plaque vascularization was smoking. Further research is warranted to elucidate the underlying mechanisms and refine risk stratification in this patient population.