Red blood cell distribution width is associated with hypoperfusion in carotid endarterectomy under regional anesthesia

The effect of the collateral cerebrovascular circulation on tolerance to carotid artery cross-clamping and on early outcome after carotid endarterectomy

OBJECTIVE

The Circle of Willis (CoW) serves as the primary source of contralateral blood supply in patients who undergo carotid artery cross-clamping (CC) for carotid endarterectomy (CEA). It has been suggested that the CoW's anatomy influences CEA outcomes. The aim of this study was to evaluate associations between the cerebral collateral circulation, a positive awake test for intraoperative neurologic deficit after carotid CC, and postoperative adverse neurologic events.

METHODS

A systematic review was conducted searching MEDLINE, Cochrane, and Web of Science databases for studies that assessed the cerebral circulation, including CoW variations, using neuroimaging techniques in patients who underwent carotid CC. For the metanalytical incidence, the statistical technique used was weight averaging. Otherwise, descriptive analysis was used due to the excessive heterogeneity of the studies.

RESULTS

Eight publications, seven cohort and one case-controlled study, involving 1313 patients who underwent carotid artery CC under loco-regional anesthesia, were included in the systematic review. The incidence of positive awake test in the cohort studies ranged from 4.4% to 19.7%. Carotid artery CC resulted in positive awake test in 5% to 91% of patients with alterations in the anterior portion and in 27% to 74% with alterations in the posterior portion of the CoW. A positive awake test in patients with contralateral carotid stenosis or occlusion ranged from 5.8% to 45.7%. Contralateral carotid stenosis >70% or occlusion were associated with a positive awake test (P < .001). Patients with incomplete CoW did not have statistically significant correlation with intraoperative neurological deficits after CC. Data were insufficient to evaluate the effect of the collateral circulation on early outcome after CEA.

CONCLUSIONS

In this systematic review, contralateral carotid artery stenosis or occlusion, but not CoW abnormalities, were associated with a positive awake test after carotid artery CC. Further research is needed to evaluate which specific CoW anomaly predicts neurologic deficit after CC and to confirm association between a positive awake test and clinical outcome after CEA.

The value of transcranial Doppler monitoring of cerebral blood flow changes during carotid endarterectomy performed under regional anesthesia - A case series

Recent evidence suggests no difference between patient outcomes when carotid endarterectomies (CEAs) are performed under general or regional anesthesia. However, for detecting the need for a shunt, general anesthesia has the drawback of monitoring needs in the intraoperative setting. In the present study, we attempted to perform intraoperative transcranial Doppler (TCD) monitoring for CEAs performed under intermediate plexus block to describe cerebral hemodynamic changes during different phases of the procedure.

Patients and methods

Patients with unilateral hemodynamically significant carotid stenosis scheduled for elective CEAs were included. Ultrasound-guided intermediate plexus block was used for regional anesthesia. TCD monitoring of the middle cerebral artery mean blood flow velocity (MCAV) was performed throughout the procedure. MCAVs were offline analyzed during different phases of CEA: (1) resting state, before regional block, (2) after block, before incision, (3) before cross-clamp, (4) after cross-clamp, (5) 5 min after cross-clamp, (6) 10 min after cross-clamp, (7) after declamping, and (8) during the postoperative period (4-6 h).

Results

Shunt insertion based on the deterioration of neurological symptoms after cross-clamping was necessary for 11/66 patients (16.6%). In these symptomatic patients, the ipsilateral percent decrease of the MCAV was more than 70% in 8 out of 11 cases (72.7%). In asymptomatic patients, without shunt insertion, the average decrease of MCAV was less than 50%.

Conclusions

Neurological symptoms referring to cerebral ischemia may be superior to TCD monitoring of cerebral blood flow for detecting the necessity of a shunt. Regional anesthesia enables reliable, symptom-based monitoring of CEAs.

The Gupta Perioperative Risk for Myocardial Infarct or Cardiac Arrest (MICA) Calculator as an Intraoperative Neurologic Deficit Predictor in Carotid Endarterectomy

Background: Patients undergoing carotid endarterectomy (CEA) may experiment intraoperative neurologic deficits (IND) during carotid cross-clamping. This work aimed to assess the impact of the Gupta Perioperative Myocardial Infarct or Cardiac Arrest (MICA) risk calculator in the IND. Methods: From January 2012 to April 2021, patients undergoing CEA with regional anaesthesia for carotid stenosis with IND and consecutively control operated patients without IND were selected. A regressive predictive model was created, and a receiver operating characteristic (ROC) curve was applied for comparison. A multivariable dependence analysis was conducted using a classification and regression tree (CRT) algorithm. Results: A total of 97 out of 194 included patients developed IND. Obesity showed aOR = 4.01 (95% CI: 1.66–9.67) and MICA score aOR = 1.21 (1.03–1.43). Higher contralateral stenosis showed aOR = 1.29 (1.08–1.53). The AUROC curve was 0.656. The CRT algorithm differentiated obese patients with a MICA score ≥ 8. Regarding non-obese patients, the model identified the presence of contralateral stenosis ≥ 55% with a MICA ≥ 10. Conclusion: MICA score might play an additional role in stratifying patients for IND in CEA. Obesity was determined as the best discrimination factor, followed by a score ≥ 8. A higher ipsilateral stenosis degree is suggested to have a part in avoiding procedure-related IND. Larger studies might validate the benefit of MICA score regarding the risk of IND.

Red Blood Cell Distribution Width Predicts Myocardial Infarction and Mortality After Vascular Surgery-A Prospective Cohort Study

BACKGROUND

This study aims to investigate the association between preoperative Red blood cell Distribution Width (RDW) and postoperative outcomes, including myocardial infarction (MI), and mortality.

METHODS

A prospective cohort including all patients submitted to elective vascular arterial surgery at a university hospital. The primary and secondary outcomes were 30-day mortality and 30-day MI, respectively.

RESULTS

Atrial fibrillation, chronic kidney disease (CKD), and dependent functional status were more prevalent in deceased patients. After multivariable analysis, age (adjusted OR 1.08, 95% Confidence Interval [1.01-1.15], p = 0.027) and RDW-standard deviation (RDW-SD) (1.08 [1.01-1.16], p = 0.032) remained independent predictors of mortality. Patients with MI had higher rates of diabetes, CKD, dependent functional status, ASA physical status IV, and insulin medication. After multivariable analysis, dependent functional status (4.8 [1.6-15.0], p = 0.007), insulin medication (4.4 [1.5-12.6], p = 0.007) and RDW-SD (1.10 [1.02-1.19], p = 0.020) were independent predictors of MI.

CONCLUSION

RDW-SD independently predicted postoperative MI and mortality, and may provide valuable information for prevention and early management of adverse outcomes.

MEAN PLATELET VOLUME PREDICTS RESTENOSIS AFTER CAROTID ENDARTERECTOMY

BACKGROUND

Carotid restenosis following carotid endarterectomy (CEA) has a cumulative risk at 5-years up to 32%, which may impact the well-being of patients following CEA. Haematological parameters in the standard complete blood cell count (CBC) are emerging as potential biomarkers, but their application in CEA is scarce. The primary aim of this study was to investigate haematological markers for restenosis following CEA. The secondary aim was to characterize clinical risk factors for restenosis.

METHODS

From January 2012 to January 2019, 151 patients who underwent CEA under regional anaesthesia due to carotid stenosis were selected from a prospectively maintained cohort database. Patients were included if a preoperative CBC was available in the two weeks preceding CEA. Multivariable analysis was performed alongside propensity score matching (PSM) analysis, using the preoperative CEA parameters, to reduce confounding factors between categories.

RESULTS

The study group comprised 28 patients who developed carotid restenosis. The remaining 123 patients without restenosis composed the control group. Mean age of the patients did not differ significantly between groups (70.25±8.05 vs. 70.32 ± 9.61 YO, p=0.973), neither did gender (male gender 89.3% vs. 78.9%, p=0.206). Regarding haematological parameters, only MPV remained statistically significant within multivariable analysis (1.855, aOR [1.174-2.931], p=0.008), a result supported by PSM analysis (2.072, aOR [1.036-4.147], p=0.042).

CONCLUSION

MPV was able to predict restenosis two years after CEA. Thus, MPV can be incorporated into score calculations to identify patients at greater risk of restenosis, who could benefit from specific monitoring during follow-up. While results are promising, more research is necessary to corroborate them.