Multimodal Neurophysiological Monitoring Reduces Shunt Incidence during Carotid Endarterectomy

Comparison of Methods for Monitoring Intra-operative Cerebral Perfusion in Patients Undergoing Carotid Endarterectomy with Selective Shunting: A Systematic Review and Network Meta-Analysis of Randomised Controlled Trials and Cohort Studies

OBJECTIVE

This study aimed to analyse the influence of different methods of monitoring cerebral perfusion (MCP) on stroke, death, and use of intraluminal shunt during carotid endarterectomy (CEA).

METHODS

A systematic review and network meta-analysis was conducted and registered in the PROSPERO registry (CRD42021246360). Medline, Embase, CENTRAL, and Web of Science were searched. Randomised controlled trials (RCTs) and cohort studies with > 50 participants that compared clinical outcomes for different MCP in patients undergoing CEA were included. Papers reporting one or a combination of two of the following MCPs were included in the analysis: awake testing (AT), near infrared spectroscopy (NIRS), electroencephalography (EEG), somatosensory evoked potential (SSEP), motor evoked potential (MEP), transcranial Doppler (TCD), and stump pressure (SP). A random effects network meta-analysis was performed using a binomial likelihood function with a specified logit link for peri-operative stroke or death and shunting as outcomes. Near infrared spectroscopy was excluded due to the lack of studies that could be used for statistical analysis.

RESULTS

Of 1 834 publications, 17 studies (15 cohort studies and two RCTs) including 21 538 participants were incorporated in the quantitative analysis. Electroencephalography was used in the largest number of participants (7 429 participants, six studies), while AT was used in the highest number of studies (10 studies). All monitoring modalities had worse outcomes with respect to stroke or death when compared with AT, with ORs ranging between 1.3 (95% credible interval [CrI] 0.2 - 10.9) for SSEP + MEP and 3.1 (CrI 0.3 - 35.0) for patients monitored with a combination of EEG and TCD. However, the wide CrI indicated that there is no statistically significant difference between the monitoring methods. Patients monitored with a combination of EEG and TCD had the lowest odds of being shunted, while SP had the highest odds of being shunted, also with no statistically significant difference.

CONCLUSION

There is a lack of high quality data on this topic in the literature. The present study showed no significant difference between monitoring methods investigated in the network meta-analysis.

A systematic review of contralateral carotid stenosis progression after carotid endarterectomy

OBJECTIVE

Progression of contralateral carotid artery stenosis after carotid endarterectomy (CEA) has been described by several authors. The aim of this study is to determine such disease progression and its related transient ischemic attacks (TIAs) or strokes by reviewing the existing literature.

METHODS

We performed a systematic literature review to select randomized controlled trials and observational studies reporting outcomes of patients treated by CEA and with concomitant contralateral carotid stenosis, regardless its degree of stenosis. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO registration number: CRD42019127595). The primary study end point was the progression of contralateral carotid artery stenosis after CEA, and the secondary end point was incidence of TIAs and strokes owing to contralateral carotid stenosis.

RESULTS

Seventeen studies were retrieved, reporting data on a total of 7679 patients who had undergone CEA, in particular they were one post hoc analysis of a randomized controlled trial, nine prospective, and seven retrospective observational studies. Among these patients, follow-up information on the contralateral carotid artery was available for 5454 cases. Disease progression was observed in 18% of patients: single class progression from mild (<50%) and from moderate (50%-70%) stenosis was observed in 15% and 23% of cases, respectively. We found 105 TIAs (4%) and 88 strokes (3%) among 2781 patients with stenosis progression, based on result from 11 studies.

CONCLUSIONS

We found a progression of contralateral carotid stenosis in a significant number of patients treated with CEA and with baseline carotid stenosis. This systematic literature review suggests that patients with moderate contralateral carotid stenosis demonstrate more rapid progression to significant or symptomatic stenosis than patients with mild contralateral stenosis.