Efficacy of near-infrared spectroscopy cerebral oximetry on detection of critical cerebral perfusion during carotid endarterectomy under regional anesthesia.

Background: Patients undergoing carotid endarterectomy (CEA) may suffer from cerebral hypoperfusion during the carotid cross-clamping. Near-infrared spectroscopy cerebral oximetry (NIRS) is a non-invasive method of regional cerebral oxygen saturation measurement reflecting changes in cerebral blood flow during CEA. The main goal of the study was to evaluate the accuracy of the NIRS in detecting cerebral hypoperfusion during CEA under regional anesthesia (RA) and compare it with awake neurological testing. Patients and methods: A prospective observational study of 28 patients that underwent CEA in RA and manifested neurologic deficits, and 28 consecutive controls from a tertiary and referral center, was performed. All patients were monitored with NIRS cerebral oximetry and awake testing as the control technique. Subsequently, operating characteristic curve and Cohen's kappa coefficient were determined to evaluate the reliability of the monitoring test. Results: NIRS presented a sensitivity of 27.3% and a specificity of 89.3% in comparison to awake testing. Receiver operating characteristic (ROC) curve analysis demonstrated that a decrease of at least 20% in cerebral oxygen saturation is the best threshold to infer cerebral hypoperfusion. However, the respective area under the curve (AUROC) was 0.606 (95% CI: 0.456-0.756, P = 0.178) with a calculated Cohen's kappa of 0.179, P = 0.093. Regarding 30-days outcomes, only awake testing has shown significant associations with stroke and postoperative complications (P = 0.043 and P = 0.05), which were higher in patients with post-clamping neurologic deficits. Conclusions: NIRS demonstrated a reduced discriminative capacity for critical cerebral hypoperfusion, and does not seem to add substantial clinical benefits to the awake test.

Onset of Neurological Deficit During Carotid Clamping With Carotid Endarterectomy Under Regional Anesthesia Is Not a Predictor of Carotid Restenosis.

BACKGROUND: A number of awake patients undergoing carotid endarterectomy (CEA) present from test clamp neurological deficits (NDs) during the procedure. Current guidelines advocate tighter Doppler ultrasound (DUS) surveillance in these patients because of probable higher likelihood of hemodynamic stroke (class 1 grade C), although evidence is lacking regarding benefit. The aim for the study is the assumption that patients who present ND have a higher risk of developing a complete stroke if the ipsilateral carotid artery becomes occluded, and for this reason, surveillance over restenosis of endarterectomy in this group is justifiable; hence, the authors would like to contribute to this matter presenting their experience on restenosis in this specific group of patients. METHODS: Data were prospectively collected between 2009 and 2018 for patients of a university tertiary referral center who underwent CEA under regional anesthesia and developed alterations in the neurologic monitoring during internal carotid artery (ICA) test clamping. Control patients were consecutively selected as the next patient submitted to the same procedure but who did not develop neurologic alterations. Patients who did not present to the first postoperative evaluation were excluded (4-6 weeks). Primary outcome was any restenosis (>30%; >50%; >70%) detected by DUS evaluations between 16 and 30 months of follow-up. Clinical adverse events such as stroke, myocardial infarction, acute heart failure, and all-cause death were assessed 30 days after the procedure and in the subsequent long-term surveillance period. A multivariate analysis of factors with significant associations to restenosis identified in a univariate analysis was performed by binary logistic regression. Kaplan-Meier analysis and life tables were used to evaluate time-dependent variables. RESULTS: Ninety patients with ND and 94 controls were included. Those with ND had a higher prevalence of obesity, mean age, and scores of American Society of Anesthesiologist physical status, as well as a lower mean degree of ipsilateral stenosis (82.3% vs. 85.8%, P = 0.032) and a higher mean degree of contralateral stenosis (67.8% vs. 61.1%, P = 0.030). The incidence of restenosis after 2 years did not differ significantly between groups. The univariate analysis yielded two significant associations to restenosis >50%, which remained significant after adjustment: ipsilateral stenosis (1.927 + -0.656, P = 0.02) and peripheral arterial disease (3.006 + -1.101, P = 0.048). NDs were not found to be associated to restenosis (P = 0.856). After a median follow-up period of 52 months, patients with NDs did not have a higher incidence of stroke (90.6%, standard deviation [SD]: 3.5%; ND: 91.1%, SD: 3.6%, P = 0.869), major adverse cardiovascular events (ND: 69.2%, SD: 5.5%; control, 73.6%, SD: 5.2%, P = 0.377), or all-cause death (ND: 90.6%, SD: 3.5%; control: 91.1, SD: 3.6%, P = 0.981) than controls. The presence of any restenosis was not associated with later stroke rate (ND: 89.5%, SD: 3.2%; control: 100%, P = 0.515). CONCLUSIONS: Cost-effective DUS surveillance after CEA requires the definition of evidence-based factors associated with restenosis and late stroke. The present study does not support the assumption that patients who presented NDs during the ICA test clamping present a higher risk of developing late stroke. This group of patients also did not present a higher incidence of restenosis. For these reasons, tighter DUS surveillance in this group seems not justifiable. Results from other groups are required to support this position.

Red Blood Cell Distribution Width as a 5-Year Prognostic Marker in Patients Submitted to Carotid Endarterectomy.

OBJECTIVE: Patients submitted to carotid artery endarterectomy (CEA) have a long-term risk of major adverse cardiovascular events (MACE) of 6-9% at 2 years. Hematological parameters have been shown to have a predictive function in atherosclerotic diseases, namely the red blood cell distribution width-coefficient of variation (RDW-CV). This parameter has been associated with worse outcomes such as myocardial infarction (MI), stroke, and all-cause mortality. This study aims to evaluate the potential role of preoperative hematologic parameters such as RDW-CV in predicting perioperative and long-term cardiovascular adverse events and mortality in patients submitted to CEA. METHODS: From January 2012 to January 2019, 180 patients who underwent CEA with regional anesthesia in a tertiary care and referral center were selected from a prospective cohort database. Blood samples were collected preoperatively 2 weeks before admission, including a full blood count. The primary outcome included long-term MACE. Secondary outcomes included all-cause mortality, stroke, MI, acute heart failure, and major adverse limb events (MALE). RESULTS: At baseline, 27.2% of patients had increased RDW-CV. Increased RDW-CV was independently associated with baseline hemoglobin (adjusted odds ratio [aOR] 0.715, 95% CI 0.588-0.869, p = 0.001) and atrial fibrillation (aOR 4.028, 95% CI 1.037-15.639, p = 0.001). After a median follow-up of 50 months, log-rank univariate analysis of RDW-CV demonstrated a significant association between increased RDW-CV and long-term all-cause mortality (log-rank <0.001), MACE (log-rank <0.001), and MI (log-rank = 0.017). After multivariate Cox regression analysis, increased RDW-CV was associated with increased long-term mortality (adjusted hazard ratio [aHR] 2.455, 95% CI 1.231-4.894, p = 0.011) and MACE (aHR 2.047, 95% CI 1.202-3.487, p = 0.008). A decreased hemoglobin to platelet ratio (aHR 2.650e-8, 95% CI 9.049e-15 to 0.078, p = 0.019) was also associated with all-cause mortality. CONCLUSION: RDW is a widely available and low-cost marker that independently predicts long-term mortality, MACE, and MI after CEA. This biomarker could prove useful in assessing which patients would likely benefit from CEA in the long term.

Prognostic effect of the new 5-factor modified frailty index in patients undergoing carotid endarterectomy with regional anesthesia - A prospective cohort study.

BACKGROUND: Frailty has been studied as a valuable predictor of adverse health events and poor postoperative outcomes in patients undergoing surgery. Thus, the use of simple and adapted indexes to define frailty, like the modified frailty index (mFI)-11, proved useful in assessing patients undergoing vascular surgery. However, the literature about the applicability of an even more pragmatic index, the modified frailty (mFI) index mFI-5 in vascular patients is scarce, particularly in those submitted to carotid endarterectomy (CEA). This study aimed to validate and estimate the prognostic value of the mFI-5 on the postoperative period and long-term survival of this population. METHODS: From January 2011 to June 2019, 184 patients from a tertiary care referral center who underwent CEA with regional anesthesia for carotid artery stenosis were selected from a previous prospectively mantained cohort database. Clinical adverse events such as stroke, myocardial infarction (MI), acute heart failure (AHF), and all-cause mortality were assessed 30-days post-procedure and in the subsequent long-term surveillance period. mFI-5 was applied to this population to evaluate the impact of frailty on mortality and morbidity. RESULTS: The mFI-5 was significantly associated with increased risk of long-term MI (P < 0.001), AHF (P = 0.043), major adverse cardiovascular events (P = 0.001) and mortality (P < 0.001). Concerning major adverse limb events and stroke survival, mFI-5 did not reveal statistical significance. The mFI-5 was not able to predict 30-day postoperative adverse events. CONCLUSION: The mFI-5 has demonstrated to be a potential index tool capable of easily stratifying patients and predicting outcomes in the long-term and add therapeutic value in the future. The mFI-5 provides a means of rapidly comparing the comorbidity charge between cohorts.

Prognostic effect of troponin elevation in patients undergoing carotid endarterectomy with regional anesthesia - A prospective study.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) occurs in 15% of patients undergoing carotid endarterectomy (CEA) with general anesthesia. Short and long-term risk of myocardial infarction (MI) and stroke have been strongly associated with the presence of MINS, with an associated mortality rate superior to 10% in the first year. Due to the absence of studies concerning CEA with regional anesthesia (RA), the present study aimed to evaluate the incidence of MINS in patients with RA and its prognostic value on cardiovascular events or death. MATERIALS AND METHODS: From January 2009 to January 2018, 156 patients from a Portuguese tertiary care medical center who underwent CEA under RA were retrieved from a prospectively gathered database. Troponin I or high-sensitive troponin I values were systematically measured in the postoperative period and studied as a binary outcome in a logistic regression model. Survival analysis was used to study the impact of MINS in time-dependent clinical outcomes such as stroke and MI. RESULTS: The incidence of MINS after CEA was 15.3%. Multivariate analysis confirmed that chronic heart failure was strongly associated with MINS (OR: 4.458, 95% CI: 1689-11.708, P < 0.001). A previously diagnosed MINS was associated with the long-term risk of MI and major adverse cardiovascular events (MACE) with hazard ratios (HR) of 3.318 (95% CI: 0.97-13.928, Breslow: P = 0.025) and 1.955 (95% CI: 1.01-4.132, Breslow: P = 0.046), respectively. CONCLUSIONS: MINS is a long-term predictor of MI and MACE. Troponin assessment after CEA should be routinely monitored in patients with a cardiovascular risk superior to 5%. Further studies concerning prophylaxis and management of MINS should be carried on, focusing on the effect of anesthetic procedure in postoperative troponin elevation.