Selective Carotid Shunting Based on Intraoperative Transcranial Doppler Imaging during Carotid Endarterectomy: A Retrospective Single-Center Review

Results of carotid endarterectomy with the use of temporary shunts with reduced retrograde pressure in the internal carotid artery - analysis of the multicenter Russian register

Aim

The aim of the study was to assess the role of a temporary carotid shunt in patients undergoing carotid endarterectomy.

Materials and methods

This was a retrospective, multicentric (n = 159) study carried out between January 2005 and October 2020. The study included 3114 patients undergoing carotid endarterectomy who had a reduced retrograde internal carotid artery pressure (<60% of systolic blood pressure). A temporary carotid shunt was used in 1328 patients and 1786 patients underwent carotid endarterectomy without a shunt.

Results

The in-hospital outcomes were comparable in terms of the incidence of deaths, myocardial infarctions, and stroke between the two groups. However, asymptomatic strokes (confirmed on computed tomography) occurred more frequently in the group where the temporary shunt was used (34 (2.5%) vs. 10 (0.55%), p < 0.0001). The composite endpoints of adverse events were also higher in the group where a temporary shunt was used (44 (3.3%) vs. 28 (1.5%), p = 0.002). The risk of symptomatic stroke (both fatal and non-fatal) was higher in the group where a temporary shunt was not used, though this was statistically not significant. Logistic regression analysis identified diabetes mellitus and stenosis (81-90%) of the contralateral internal carotid artery to be important predictors for stroke.

Conclusion

Temporary carotid shunts during carotid endarterectomy were associated with increased rates of asymptomatic stroke. There were no statistically significant differences in the incidence of non-fatal or fatal stroke, myocardial infarction, and mortality.

Update in Carotid Disease

This review of the literature analyzes publications over the past five years on various problems associated with carotid endarterectomy: 1. Is the eversion or classical technique of surgery with plastic repair of the reconstruction area with a patch more effective? 2. Carotid endarterectomy or carotid angioplasty with stenting is more optimal? 3. When should brain revascularization be performed after the development of ischemic stroke? 4. Should a temporary shunt be used to protect the brain during carotid endarterectomy? 5. How to prevent and treat different types of intraoperative ischemic strokes? 6. What tactics of treatment of patients with combined lesions of the carotid and coronary arteries is more effective? 7. What are the causes and methods of elimination of restenosis of the internal carotid artery known? 8. Is carotid endarterectomy safe in old age?

Outcomes of Carotid Endarterectomy according to the Anesthetic Method: General versus Regional Anesthesia

Background

The surgical strategies for carotid endarterectomy (CEA) vary in terms of the anesthesia method, neurological monitoring, shunt usage, and closure technique, and no gold-standard procedure has been established yet. We aimed to analyze the feasibility and benefits of CEA under regional anesthesia (RA) and CEA under general anesthesia (GA).

Methods

Between June 2012 and December 2017, 65 patients who had undergone CEA were enrolled, and their medical records were prospectively collected and retrospectively reviewed. A total of 35 patients underwent CEA under RA with cervical plexus block, whereas 30 patients underwent CEA under GA. In the RA group, a carotid shunt was selectively used for patients who exhibited negative results on the awake test. In contrast, such a shunt was used for all patients in the GA group.

Results

There were no cases of postoperative stroke, cardiovascular events, or mortality. Nerve injuries were noted in 4 patients (3 in the RA group and 1 in the GA group), but they fully recovered prior to discharge. Operative time and clamp time were shorter in the RA group than in the GA group (119.29±27.71 min vs. 161.43±20.79 min, p<0.001; 30.57±6.80 min vs. 51.77±13.38 min, p<0.001, respectively). The hospital stay was shorter in the RA group than in the GA group (14.6±5.05 days vs. 18.97±8.92 days, p=0.022). None of the patients experienced a stroke or restenosis during the 27.23±20.3-month follow-up period.

Conclusion

RA with a reliable awake test reduces shunt use and decreases the clamp and operative times of CEA, eventually resulting in a reduced length of hospital stay.

Near-Infrared Spectroscopy versus Transcranial Doppler-Based Monitoring in Carotid Endarterectomy

Background

Proper monitoring of cerebral perfusion during carotid artery surgery is crucial for determining if a shunt is needed. We compared the safety and reliability of near-infrared spectroscopy (NIRS) with transcranial Doppler (TCD) for cerebral monitoring.

Methods

This single-center, retrospective review was conducted on patients who underwent carotid endarterectomy (CEA) using selective shunt-based TCD or NIRS at Daegu Catholic University Medical Center from November 2009 to June 2016. Postoperative complications were the primary outcome, and the distribution of risk factors between the 2 groups was compared.

Results

The medical records of 74 patients (45 TCD, 29 NIRS) were reviewed. The demographic characteristics were similar between the 2 groups. One TCD patient died within the 30-day postoperative period. Postoperative stroke (n=4, p=0.15) and neurologic complications (n=10, p=0.005) were only reported in the TCD group. Shunt usage was 44.4% and 10.3% in the TCD and NIRS groups, respectively (p=0.002).

Conclusion

NIRS-based selective shunting during CEA seems to be safe and reliable for monitoring cerebral perfusion in terms of postoperative stroke and neurologic symptoms. It also reduces unnecessary shunt usage.

Dual Monitoring with Stump Pressure and Electroencephalography During Carotid Endarterectomy

BACKGROUND

Intraoperative monitoring during carotid endarterectomy is crucial for cerebral protection. We investigated the results of carotid endarterectomy under dual monitoring with stump pressure and electroencephalography.

METHODS

We retrospectively reviewed the medical records of 50 patients who underwent carotid endarterectomy between March 2010 and February 2016. We inserted a temporary shunt if the stump pressure was lower than 35 mm Hg or if any intraoperative change was observed on electroencephalography.

RESULTS

Seventeen (34%) patients used a temporary shunt, and the mean stump pressure was 26.8 mm Hg in the shunt group and 46.5 mm Hg in the non-shunt group. No postoperative mortality or bleeding occurred. Postoperatively, there were 3 cases (6%) of minor stroke, all of which took place in the shunt group. A comparison of the preoperative and the intraoperative characteristics of the shunt group with those of the non-shunt group revealed no statistically significant difference between the 2 groups (p <0.01).

CONCLUSION

Dual monitoring with stump pressure and electroencephalography was found to be a safe and reliable monitoring method with results comparable to those obtained using single monitoring. Further study should be performed to investigate the precise role of each monitoring method.