Impact of Shunting Practice Patterns During Carotid Endarterectomy for Symptomatic Carotid Stenosis

A systematic review and meta-analysis on the outcomes of carotid endarterectomy after intravenous thrombolysis for acute ischemic stroke

BACKGROUND

Intravenous thrombolysis (IVT) is the mainstay of treatment for patients presenting with acute ischemic stroke, whereas carotid endarterectomy (CEA) is indicated in patients with symptomatic carotid stenosis. However, the impact of prior IVT on the outcomes of CEA (IVT-CEA) is not clear. The aim of this study was to determine whether IVT may create additional stroke and death risk for CEA, compared with CEA performed in the absence of a history of recent IVT, and to determine the optimal timing for CEA after IVT.

METHODS

We conducted a systematic review and meta-analysis of studies comparing the outcomes of IVT-CEA vs CEA, using the Medline, Embase, and Cochrane databases.

RESULTS

We included 11 retrospective comparative studies, in which 135,644 patients underwent CEA and 2070 underwent IVT-CEA. The pooled rate of perioperative stroke was 4.2% in the IVT-CEA group and 1.3% in the CEA group (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.12-1.58; P = .21), with a high heterogenicity (I2 = 93%). The rate of stroke/death was 5.9% in patients undergoing IVT-CEA 1.9% in those receiving CEA only (OR, 0.42; 95% CI, 0.15-1.14; I2 = 92%; P = .09); after exclusion of studies including TIA as presenting symptom, stroke/death risk was 3.6% in IVT-CEA and 3.0% in CEA (OR, 1.42; 95% CI, 0.80-2.53; I2 = 50%; P = .11). The risk of stoke decreased with a delay in the performance of CEA (P = .268). Using results of the metaregression, the calculated delay of CEA that allows for a <6% risk was 4.6 days. Compared with CEA, patients undergoing IVT-CEA had a significantly higher risk of intracranial hemorrhage (2.5% vs 0.1%; OR, 0.11; 95% CI, 0.06-0.21; I2 = 28%; P < .001) and neck hematoma requiring reintervention (3.6% vs 2.3%; OR, 0.61; 95% CI, 0.43-0.85; I2 = 0%; P = .003).

CONCLUSIONS

In patients presenting with an acute ischemic stroke, CEA can be safely performed after a prior endovenous thrombolysis, maintaining a stroke/death risk of <6%. After IVT, CEA should be deferred for ≥5 days to minimize the risk for intracranial hemorrhage and neck bleeding.

Carotid Endarterectomy With Shunt-A Stepwise Surgical Technique Demonstration for Trainees: 2-Dimensional Operative Video

Carotid endarterectomy (CEA) is a common cerebrovascular surgery and is an effective treatment option for patients with carotid stenosis. 1-4 Although the routine or selective use of a shunt is still debatable, 5 the CEA technique is generally well-established. We believe that bloodless and “shallow and wide” operative fields make CEA safe and successful. Maintaining a bloodless operative field is highly crucial to prevent postoperative cervical hematoma and damage to anatomic structures, such as the hypoglossal and vagus nerves, because it facilitates their identification. In the cases of CEA, antiplatelet medications are usually continued, and systemic heparinization is performed intraoperatively; therefore, further meticulous hemostasis should be performed than in other neurological surgery cases. The 2-step pull-up technique, which involves pulling up loose connective tissue surrounding the carotid arteries in addition to the carotid sheath, makes the operative field “shallow and wide.” This technique allows the internal carotid artery to move from deep to superficial, making CEA feasible, particularly when placing a shunt. This video illustrates the CEA technique used for symptomatic mild carotid stenosis in a 66-year-old man with vulnerable plaques. Evolving carotid artery stenting should facilitate the improvement of the operative technique to increase the safety and accordingly train young surgeons. This video is intended to increase familiarity with CEA because carotid artery stenting decreases CEA indications for carotid stenosis and diminishes proficiency in managing CEA. The patient consented to the publication of his image. Patient consent was obtained to perform the surgery and publish the surgical video.

Hybrid repair of tandem high-grade innominate and carotid artery stenosis in an asymptomatic male

Tandem atherosclerotic lesions of the innominate artery (IA) and internal carotid artery (ICA) are challenging and represent an inherent risk of cerebrovascular accident. Treating asymptomatic patients is controversial; therefore, it is critical to minimize the risk of a cerebrovascular accident if repair is undertaken. An asymptomatic 78-year-old man with a chronically occluded left ICA and tandem stenoses of the IA and right ICA underwent a hybrid intervention with stenting of the IA lesion and right ICA endarterectomy. The intra- and postoperative course was successful, without any signs of neurological sequelae. Sixteen months later, the patient remained asymptomatic, with patent reconstructions.

Incomplete circle of Willis as a risk factor for intraoperative ischemic events during carotid endarterectomies performed under regional anesthesia - A prospective case-series

Background

The role of the willisian collaterals during carotid endarterectomies (CEAs) is a debated issue. The aim of the present work was to test whether an incomplete or non-functional circle of Willis (CoW) is a risk factor for ischemic events during CEA.

Patients and methods

CEAs were performed under local anesthesia. Patients were considered symptomatic (SY) if neurological signs appeared after the cross-clamping phase. In SY patients shunt insertion was performed. CoW on CT angiograms (CTa) were analyzed offline and categorized as non-functional (missing or hypoplastic collaterals) or functional collaterals by three neuroradiologists. Near-infrared spectroscopy (NIRS) was performed throughout the procedure.

Results

Based on CTa, 67 incomplete circles were found, 54 were asymptomatic (ASY) and 13 were SY. No complete CoW was found among the SY patients. Significant differences could be detected between incomplete and complete circles between ASY and SY groups (Chi-square: 6.08; p = 0.013). The anterior communicating artery was missing or hypoplastic in 5/13 SY cases. There were no cases of the non-functional anterior communicating arteries in the ASY group (Chi-square: 32.9; p = 10^-8). A missing or non-functional bilateral posterior communicating artery was observed in 9/13 SY and in 9/81 ASY patients (Chi-square: 24.4; p = 10^-7). NIRS had a sensitivity of 76.9% and a specificity of 74.5% in detecting neurological symptoms.

Conclusions

Collateral ability of the CoW may be a risk factor for ischemic events during CEAs. Further studies should delineate whether the preoperative assessment of collateral capacity may be useful in decision-making about shunt use during 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.

Unplanned Shunting Is Associated with Higher Stroke Risk after Eversion Carotid Endarterectomy

BACKGROUND

Shunting during eversion carotid endarterectomy (eCEA) may be technically challenging. Whether shunting practice patterns modify perioperative stroke risk after eCEA is unclear. We aimed to compare eCEA outcomes based on shunting practice.

METHODS

The Vascular Quality Initiative (2011-2019) was queried for eCEAs performed for symptomatic and asymptomatic carotid stenosis. Univariable and multivariable analyses compared outcomes based on whether shunting was routine practice, preoperatively-indicated, intraoperatively-indicated, or not performed.

RESULTS

There were 13,207 eCEAs identified. Average age was 71.4 years and 59.4% of patients were male sex. Ipsilateral carotid stenosis was >80% in 45.6% and there was severe contralateral carotid stenosis in 8.6%. Early ipsilateral symptoms within 14 days of eCEA were transient ischemic attack in 5.6% and stroke in 7%. The majority of cases were performed under general anesthesia (82.7%). Electroencephalogram monitoring and stump pressures were utilized in 30.9% and 14.7%, respectively. Shunting was routine (25.4%), preoperatively-indicated (1.9%), intraoperatively-indicated (4.7%), or not implemented (68%). Preoperatively-indicated shunting was more often performed in patients with early symptomatic carotid stenosis or severe contralateral carotid stenosis. After routine shunting, preoperatively-indicated shunting, intraoperatively-indicated shunting, and no shunting, median operative duration was 110, 101, 112, and 97 min, respectively (P < 0.001), and ipsilateral perioperative stroke prevalence was 0.6%, 1.2%, 1.9%, and 0.7%, respectively (P = 0.004). On multivariable analysis, longer operative time was associated with routine shunting (MR 1.17, 95% CI 1.15-1.19, P < 0.001), preoperatively-indicated shunting (MR 1.09, 95% CI 1.04-1.15, P < 0.001), and intraoperatively-indicated shunting (MR 1.12, 95% CI 1.09-1.16, P < 0.001) compared with no shunting. Compared with no shunting, routine shunting (OR 0.91, 95% CI 0.54-1.54, P = 0.74) and preoperatively-indicated shunting (OR 1.53, 95% CI 0.47-4.99, P = 0.48) were not associated with stroke; however, intraoperatively-indicated shunting was associated with increased stroke (OR 2.74, 95% CI 1.41-5.3, P = 0.003). Shunting type was not associated with perioperative mortality.

CONCLUSIONS

Intraoperatively-indicated shunting during eCEA was associated with longest operative duration and increased perioperative stroke risk. Surgeon familiarity with shunting and planning to shunt in advance may permit more expeditious shunting and prevent stroke.