Carotid Endarterectomy with Routine Shunt for Patients with Contralateral Carotid Occlusion

Carotid Endarterectomy

Stroke is the second leading cause of death worldwide. One of the main causes of stroke is carotid artery stenosis. Stenosis with atherosclerosis in the carotid artery can cause stroke by hemodynamic ischemia or artery to artery embolism. A most common surgical intervention for carotid artery stenosis is carotid endarterectomy (CEA). Many studies on CEA have been reported and suggested medical indications. For symptomatic carotid stenosis, generally, CEA may be indicated for patients with more than 50% stenosis and is especially beneficial in men, patients aged 75 years or older, and patients who underwent surgery within 2 weeks of their last symptoms. For asymptomatic carotid stenosis, CEA may be indicated for those with more than 60% stenosis, though each guideline has different suggestions in detail. In order to evaluate the indication for CEA in each case, it is important to assess risks for CEA carefully including anatomical factors and comorbidities, and to elaborate each strategy for each operation based on preoperative imaging studies including carotid ultrasonography, magnetic resonance imaging and angiography. In surgery there are many tips on operative position, procedure, shunt usage and monitoring to perform a safe and smooth operation. Now that carotid artery stenting has been rapidly developed, better understanding for CEA is required to treat carotid artery stenosis adequately. This chapter must be a good help to understand CEA well.

Long-term outcomes of symptomatic and asymptomatic patients undergoing carotid endarterectomy in an average-volume community hospital

BACKGROUND

Long-term benefit of carotid endarectomy has not yet been fully investigated in average volume centers. Thus our purpose is to evaluate long-term results of carotid endarterectomies at a medium-volume hospital.

METHODS

A retrospective analysis of carotid artery stenosis operated between 2008 and 2017 in a community hospital was done. Demographic and postoperative outcomes were evaluated in short and long-term by Kaplan-Meier survival analysis.

RESULTS

167 procedures in 159 patients were included. Average age was 72 years, and 65% were men. Twenty-nine percent of the patients were symptomatic and the rest asymptomatic. Median hospitalization was 3 (IQR 3-4) days and the mean follow-up was 56 months. No hospital mortality was recorded. At 120-month follow-up, freedom of stroke was 97.4%, death 97.3%, restenosis, 98.7% and all combined events 92.9% (log rank p = .042) Combined event-free survival was 84.4% in symptomatic patients, and 96.1% in asymptomatic patients (log rank p = .025).

CONCLUSIONS

In a medium-volume hospital combined event-free survival was 84.4% in symptomatic patients and 96.1% in asymptomatic at a 10-year follow-up.

Selective internal carotid artery cross-clamping increases the specificity of cerebral oximetry for indication of shunting during carotid endarterectomy

BACKGROUND

An indication for selective shunting during carotid endarterectomy (CEA) is based on monitoring during a procedure. Cerebral oximetry (CO) using near-infrared spectroscopy (NIRS) may be a simple technique, but its relevance during CEA, especially with respect to cutoff values indicating shunt implantation, still needs to be elucidated.

METHODS

One hundred twenty five patients underwent CEA under local anesthesia (LA) and were monitored clinically throughout the whole procedure. The patients were also monitored using bilateral NIRS probes during surgery. The NIRS values were recorded and evaluated before and after selective cross-clamping, firstly by the external carotid artery (ECA), followed by the internal carotid artery (ICA). The decrease in the ipsilateral CO values, with respect to the indication of shunting, was only analyzed after selective cross-clamping of the ICA. The decision to use an intraluminal shunt was solely based on the neurological status evaluation after ICA cross-clamping.

RESULTS

One hundred five patients (85%) were stable throughout the CEA, while 20 patients (15%) clinically deteriorated during surgery. The mean drop in the CO after selective ICA clamping in clinically stable patients was 6%, while in patients with clinical deterioration, the NIRS decreased by 14.5% (p < 0.05). When the cutoff value for selective shunting was set as a 10% decrease of the ipsilateral CO after selective ICA clamping, the sensitivity of the technique was 100% and the specificity 83.0%.

CONCLUSIONS

Our study showed that a 10% decrease in the ipsilateral brain tissue oximetry after selective cross-clamping the ICA provides a reliable cutoff value for selective shunting during CEA. Despite the availability of a variety of monitoring tools, the NIRS may be an easy, reliable option, especially in the scenario of acute CEA in general anesthesia.

Severe contralateral carotid stenosis or occlusion drive 30-day risk after carotid endarterectomy

OBJECTIVES

The significant effects on the treatment of severe carotid stenosis by carotid endarterectomy have been widely recognized. However, it is controversial whether patients with severe contralateral carotid stenosis or occlusion (SCSO) can benefit from carotid endarterectomy surgery. This study aimed to estimate the SCSO effects on early outcomes after carotid endarterectomy with selective shunting.

METHODS

Between August 2011 and October 2019, a total of 617 patients who underwent carotid endarterectomy with selective shunting were analyzed. SCSO was defined as >70% luminal narrowing of the contralateral extracranial carotid stenosis or occlusion. Of these patients, 116 were categorized into an SCSO group while the rest were assigned to the non-SCSO group. Primary study outcomes were the occurrence of major adverse events, defined as stroke, all-cause mortality, and myocardial infarction during the perioperative period after carotid endarterectomy. Traditional multivariable logistic regression model and logistic regression model adjusted for propensity scores were used to estimate the SCSO effects on primary outcomes. Interaction and stratified analyses were conducted according to age, sex, comorbidities (hypertension, diabetes), preoperative neurological deficit, preoperative symptoms, and shunt use.

RESULTS

Mean age was 68.5 ± 9.2 years (86.1% men). Overall major adverse events rate within 30 days was 2.5%. Major adverse events rates in SCSO and non-SCSO groups were 9.5% and 1.6%, respectively. This difference was statistically significant (p < 0.001). In multivariable regression analysis, patients with SCSO had a higher risk of major adverse events (non-SCSO vs. SCSO: aOR 5.05 [95% CI, 1.78-14.55]). In 342 propensity score matched patients, results were consistent (propensity score: aOR, 3.78 [95% CI, 1.13-12.64]).

CONCLUSIONS

SCSO is an independent predictor of 30-day major adverse events. Whether these patients with SCSO are suitable for carotid endarterectomy should be carefully considered.

Surgical Technique for Carotid Endarterectomy: Current Methods and Problems

Over the last 60 years, many reports have investigated carotid endarterectomy (CEA) and techniques have thus changed and improved. In this paper, we review the recent literature regarding operational maneuvers for CEA and discuss future problems for CEA. Longitudinal skin incision is common, but the transverse incision has been reported to offer minimal invasiveness and better cosmetic effects for CEA. Most surgeons currently use microscopy for dissection of the artery and plaque. Although no monitoring technique during CEA has been proven superior, multiple monitors offer better sensitivity for predicting postoperative neurological deficit. To date, data are lacking regarding whether routine shunt or selective shunt is better. Individual surgeons thus need to select the method with which they are more comfortable. Many surgical techniques have been reported to obtain distal control of the internal carotid artery in patients with high cervical carotid bifurcation or high plaque, and minimally invasive techniques should be considered. Multiple studies have shown that patch angioplasty reduces the risks of stroke and restenosis compared with primary closure, but few surgeons in Japan have been performing patch angioplasty. Most surgeons thus experience only a small volume of CEAs in Japan, so training programs and development of in vivo training models are important.

[Cerebral protection from ischaemia during carotid endarterectomy]

The purpose of this study was to assess efficacy of cerebral protection during carotid endarterectomy by means of controlled systemic hypertension in patients presenting with various levels of retrograde pressure in the internal carotid artery. The study enrolled a total of 150 patients subjected to carotid endarterectomy. The operation was carried out under general anaesthesia with artificial pulmonary ventilation and was accompanied by haemodynamic monitoring with invasive control of arterial pressure, as well as primary and additional correction of central haemodynamics. Cerebral perfusion was assessed by measuring retrograde pressure in the internal carotid artery. The retrograde pressure index was calculated, according to which the patients were subdivided into three groups: those with values less than 30, with values from 30 to 39, and with values of 40 and more. Controlled systemic arterial hypertension was used as cerebral protection during the period of cross-clamping of the internal carotid artery, with phenylephrine and norepinephrine administered for this purpose. The parameters of central haemodynamics, time intervals of the operation, and the duration of internal carotid artery cross-clamping in the groups did not statistically differ (p>0.05). A statistically significant difference was revealed in the level of systolic arterial pressure necessary for cerebral protection (p<0.05). There were no cerebral circulation impairments, myocardial infarctions, nor lethal outcomes. A conclusion was drawn that individualized correction of central haemodynamics ensured a sufficient level of collateral compensation of the cerebral blood flow, thus making it possible to refuse from using intraluminal shunts.

Ultrasound-guided superficial cervical plexus block under dexmedetomidine sedation versus general anesthesia for carotid endarterectomy: a retrospective pilot study

Background

Carotid endarterectomy (CEA) has been performed under regional and general anesthesia (GA). The general anesthesia versus local anesthesia for carotid surgery study compared the two techniques and concluded that there was no difference in perioperative outcomes. However, since this trial, new sedative agents have been introduced and devices that improve the delivery of regional anesthesia (RA) have been developed. The primary purpose of this pilot study was to compare intraoperative hemodynamic stability and postoperative outcomes between GA and ultrasound-guided superficial cervical plexus block (UGSCPB) under dexmedetomidine sedation for CEA.

Methods

Medical records from 43 adult patients who underwent CEA were retrospectively reviewed, including 16 in the GA group and 27 in the RA group. GA was induced with propofol and maintained with sevoflurane. The UGSCPB was performed with ropivacaine under dexmedetomidine sedation. We compared the intraoperative requirement for vasoactive drugs, postoperative complications, pain scores using the numerical rating scale, and the duration of hospital stay.

Results

There was no difference between groups in the use of intraoperative antihypertensive drugs. However, intraoperative inotropic and vasopressor agents were more frequently required in the GA group (p<0.0001). In the GA group, pain scores were significantly higher during the first 24 h after surgery (p<0.0001 between 0-6 h, p<0.004 between 6-12 h, and p<0.001 between 12-24 h). The duration of hospital stay was significantly more in the GA group (13.3±4.6 days in the GA group vs. 8.5±2.4 days in the RA group, p<0.001).

Conclusion

In this pilot study, intraoperative hemodynamic stability and postoperative outcomes were better in the RA compared to the GA group.