Shunting In Carotid Endarterectomy Research Articles

Selective Shunting in Carotid Endarterectomy Based on Circle of Willis Assessment Reduced Perioperative Neurologic Event and Stroke Rates

Selective Shunting in Carotid Endarterectomy Based on Circle of Willis Assessment Reduced Perioperative Neurologic Event and Stroke Rates

Can NIRS be a surrogate indicator of elective shunt in carotid endarterectomy? A single-center observational retrospective study says no.

Neuromonitoring during carotid endarterectomy (CEA) under general anesthesia is desirable and may be useful for preventing brain ischemia, but the selection of the most appropriate method remains controversial. To determine the effectiveness of near infrared spectroscopy (NIRS) compared to multimodality intraoperative neuromonitoring (IONM) in indicating elective shunts and predicting postoperative neurological status. This is a retrospective observational study including 86 consecutive patients with CEA under general anesthesia. NIRS and multimodality IONM were performed during the procedure. IONM included electroencephalography (EEG), somatosensory evoked potentials (SSEPs) and transcranial motor-evoked potentials (TcMEPs). Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated for each neuromonitoring modality. NIRS presented a sensitivity and a specificity for detecting brain ischemia of 77.7% and 89.6%, respectively (PPV = 46.6% and NPV = 97.2%). In contrast, a 100% sensitivity and specificity for multimodality IONM was determined (PPV and NPV = 100%). No significant difference (in demographical or clinical data) between "true positive" and "false-positive" patients was identified. Among the methods included in multimodality IONM, EEG showed the best results for predicting postoperative outcome after CEA (PPV and NPV=100%). NIRS is inferior to multimodality IONM in detecting brain ischemia and predicting postoperative neurological status during CEA under general anesthesia.

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting).

Temporary interruption of cerebral blood flow during carotid endarterectomy can be avoided by using a shunt across the clamped section of the carotid artery. The shunt may improve the outcome. This is an update of a Cochrane review originally published in 1996 and previously updated in 2002, 2009, and 2014. To assess the effect of routine versus selective or no shunting, and to assess the best method for selective shunting on death, stroke, and other complications in people undergoing carotid endarterectomy under general anaesthesia. We searched the Cochrane Stroke Group Trials Register (last searched April 2021), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2021, Issue 4), MEDLINE (1966 to April 2021), Embase (1980 to April 2021), and the Science Citation Index Expanded (SCI-EXPANDED) (1980 to April 2021). We also searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform, and handsearched relevant journals, conference proceedings, and reference lists. Randomised and quasi-randomised trials of routine shunting compared with no shunting or selective shunting, and trials that compared different shunting policies in people undergoing carotid endarterectomy. Three independent review authors performed data extraction, selection, and analysis. A pooled Peto odds ratio (OR) and 95% confidence interval (CI) were computed for all outcomes of interest. Best and worse case scenarios were also calculated in case of unavailable data. Two authors independently assessed risk of bias, and quality of evidence using GRADE. No new trials were found for this updated review. Thus, six trials involving 1270 participants are included in this latest review: three trials involving 686 participants compared routine shunting with no shunting, one trial involving 200 participants compared routine shunting with selective shunting, one trial involving 253 participants compared selective shunting with and without near-infrared refractory spectroscopy monitoring, and the other trial involving 131 participants compared shunting with a combination of electroencephalographic and carotid pressure measurement with shunting by carotid pressure measurement alone. Only three trials comparing routine shunting and no shunting were eligible for meta-analysis. Major findings of this comparison found that the routine shunting had less risk of stroke-related death within 30 days of surgery (best case) than no shunting (Peto odds ratio (OR) 0.13, 95% confidence interval (CI) 0.02 to 0.96, I2 not applicable, P = 0.05, low-quality evidence), the routine shunting group had a lower stroke rate within 24 hours of surgery (Peto odds ratio (OR) 0.15, 95% CI 0.03 to 0.78, I2 = not applicable, P = 0.02, low-quality evidence), and ipsilateral stroke within 30 days of surgery (best case) (Peto OR 0.41, 95% CI 0.18 to 0.97, I2 = 52%, P = 0.04, low-quality evidence) than the no shunting group. No difference was found between the groups in terms of postoperative neurological deficit between selective shunting with and without near-infrared refractory spectroscopy monitoring. However, this analysis was inadequately powered to reliably detect the effect. There was no difference between the risk of ipsilateral stroke in participants selected for shunting with the combination of electroencephalographic and carotid pressure assessment compared with pressure assessment alone, although again the data were limited. This review concluded that the data available were too limited to either support or refute the use of routine or selective shunting in carotid endarterectomy when performed under general anaesthesia. Large-scale randomised trials of routine shunting versus selective shunting are required. No method of monitoring in selective shunting has been shown to produce better outcomes.

Early outcomes of routine delayed shunting in carotid endarterectomy for symptomatic patients.

The role of shunting during carotid endarterectomy (CEA) in symptomatic patients is unclear. The aim was to evaluate early outcomes of CEA with routine "delayed" shunt insertion, for patients with symptomatic carotid stenosis. We conducted a single-center retrospective study of symptomatic patients undergoing CEA (2009-2020). All CEAs were performed under general anesthesia using a standardized technique, based on delayed routine shunt insertion after plaque removal. Primary endpoints were 30-days mortality and stroke. A logistic regression was performed to identify clinical and procedural factors associated with postoperative stroke. Two-hundred-sixty-three CEAs were performed for TIA (N.=178, 47%) or acute ischemic stroke (N.=85, 32%). Mean delay of surgery was 6±19 days, and early CEA (<48 hours) was performed in 98 cases (37%). Conventional CEA was performed in 171 patients (67%), eversion CEA in 83 (33%). Early (30-days) mortality was 0.3%. Stroke/death rate was 2.3%. Female sex (OR=5.14, 95% CI: 1.32-24.93; P=0.023), use of anticoagulants (OR=10.57, 95% CI: 2.67-51.86; P=0.001), preoperative stroke (OR=5.34, 95% CI: 1.62-69.21; P=0.006), and the presence of preoperative CT/MRI cerebral ischemic lesions (OR=5.96, 95% CI: 1.52-28.59; P=0.013) were associated with early neurological complications. Statin medication (OR=0.18, 95% CI: 0.04-0.71; P=0.019) and CEA timing <2 days (OR=0.14, 95% CI: 0.03-0.55; P=0.005) were protective from postoperative stroke. CEA outcomes were independent from time period (P=0.201) and operator's volume (P=0.768). A literature systematic review identified other four studies describing the CEA outcomes with routine shunting in symptomatic patients, with a large variability in the selection of patients, surgical technique, and description of the results. Routine delayed shunting after plaque removal seems to be a safe and effective technique, that contributed to maintain a low complication rate in neurologically symptomatic patients. Statin use and expedited timing were associated with improved outcomes using this technique.

Somatosensory Evoked Potential and Transcranial Doppler Monitoring to Guide Shunting in Carotid Endarterectomy.

Clamping of the internal carotid artery (ICA) during carotid endarterectomy (CEA) is a critical step. In our neurosurgical department, CEAs are performed with transcranial Doppler (TCD) and somatosensory evoked potential (SEP) monitoring with a 50% flow velocity/amplitude decrement warning criteria for shunting. The aim of our study was to evaluate our protocol with immediate neurologic deficits after surgery for the primary end point. This is a single-center retrospective cohort study of symptomatic and asymptomatic ICA stenosis patients from January 2012 to June 2015. Only those cases in which CEA was performed with both modalities (TCD and SEP) were included. The Mann-Whitney U test was applied to evaluate TCD and SEP ratios based on immediate postoperative neurologic deficits. A total of 144 patients were included, 120 (83.3%) with symptomatic ICA stenosis. The primary end point was met by six patients (4.2%); all of them were patients with a symptomatic ICA stenosis. The stroke and death rate was 1.4%. Ratios of SEP amplitudes demonstrated significant differences between patients with and without an immediate postoperative neurologic deficit at the time of ICA clamping (p = 0.005), ICA clamping at 10 minutes (p = 0.044), and ICA reperfusion (p = 0.005). Ratios of TCD flow velocity showed no significant difference at all critical steps. In this retrospective series of simultaneous TCD and SEP monitoring during CEA surgery of predominantly symptomatic ICA stenosis patients, the stroke and death rate was 1.4%. SEP seemed to be superior to TCD in predicting the need for an intraoperative shunt and for predicting temporary postoperative deficits. Further prospective studies are needed.

Early Outcomes of Routine Delayed Shunting in Carotid Endarterectomy for Symptomatic Patients

Early Outcomes of Routine Delayed Shunting in Carotid Endarterectomy for Symptomatic Patients

IP089. Early Outcomes of Routine Delayed Shunting in Carotid Endarterectomy for Symptomatic Patients

IP089. Early Outcomes of Routine Delayed Shunting in Carotid Endarterectomy for Symptomatic Patients

Early Outcomes of Routine Delayed Shunting in Carotid Endarterectomy for Asymptomatic Patients

The aim was to evaluate early outcomes of carotid endarterectomy (CEA) in asymptomatic patients using a standardised technique based on routine shunting after rapid plaque removal ("delayed"). A retrospective review of all asymptomatic patients who underwent CEA during a 10 year single centre experience (January 2007-December 2016) was performed. The technique was based on rapid endarterectomy with distal intimal edge visualisation, followed by routine shunt insertion; subsequent time spent on the manoeuvre and closure were completed under shunting. Primary endpoints were relevant neurological complication rate (RNCR) and death within 30 days. To better identify any difference related to changes in medical therapy, anaesthetic management, and different operators over time, patients were divided into group A (underwent CEA in the first 5 year period) and group B (underwent CEA during the second 5 year period). Univariate analysis of factors associated with RNCR was performed. Operator experience (seniority), expertise (CEA volume per year), and time period were incorporated. In total, 1745 patients matched the inclusion criteria and were enrolled. Altogether, 147 (8.9%) had contemporary contralateral stenosis ≥70% and 58 (3.5%) had contralateral internal carotid artery chronic occlusion. No patient died peri-operatively; major myocardial infarction occurred in 19 patients (1.1%). Overall, peri-operative RNCR was 0.6% (major stroke: n=6 [0.4%]; minor stroke: n=4 [0.2%]). RNCR distribution was maintained equally comparing group A and B (0.8% vs. 0.4%; p=0.17). No differences were found in RNCR when comparing operator experience (p=0.88) and expertise (p=0.93). Univariable analysis found diabetes as the only clinical factor influencing RNCR (odds ratio 3.79, 95% confidence interval 1.06-13.50; p=0.04); none of the other factors, such as time period, operator experience, and expertise, reached statistical significance. Routine delayed shunting associated with standardisation of the technique seems to be a safe and effective technique and contributes to maintaining the RNCR<1% over time and independently from operators and other clinical factors.

Carotid endarterectomy: neither shunting nor patching technique.

Introduction The role of carotid shunting in carotid endarterectomy is controversial. Many studies have concluded that patch angioplasty is preferable to primary closure, while others found that it had no value. The aim of this study was to report the results of our first series of patients undergoing carotid endarterectomy with a non-shunting technique and primary closure of the arteriotomy. Methods From October 2014 to October 2017, 63 patients with unilateral or bilateral carotid artery stenosis underwent carotid endarterectomy. There were 48 males and 15 females, the mean age was 63.16 years, and all were symptomatic. Conventional endarterectomy was performed without a shunt in all cases. All arteriotomies were closed primarily. We analysed the early and late outcomes of this procedure with at least 18 months of follow-up. Results Diabetes was the most frequent comorbidity. Most of the patients had a history of transient ischemic attack (49.2%) or stroke (44.4%). All patients had significant (moderate to severe) carotid artery stenosis. Postoperatively, 2 (3.2%) patients developed ischemic stroke, one (1.6%) suffered hypoglossal nerve injury, and one had a postoperative cervical hematoma. During follow-up, one patient developed asymptomatic total occlusion of the endartrectomized carotid artery at 18 months. Conclusion Carotid endarterectomy without shunting is a safe procedure. The short- and longer-term outcomes are not significantly inferior to those of the routine or selective shunting technique, and the rate of restenosis is not higher than that of patch angioplasty closure.

Advantages of Selective Use of Intraluminal Shunt in Carotid Endarterectomy: A Study of 122 Cases.

Objectives: To assess the advantage of selective use of shunt in carotid endarterectomy (CEA) under local anesthesia. Materials and Methods: A total of 122 consecutive patients fulfilling international guidelines were included. Shunt was used selectively only in cases of bilateral severe carotid artery occlusive disease or in those patients who developed neurological symptoms on clamping of carotid artery. Follow up was done weekly for one month; then every month for 3 months; and then every 3 months for a year. Results: Shunt was used only in 5% (n = 6) patients. Of these, 2.5% (n = 3) patients were those who developed neurological symptoms on clamping the internal carotid and deployment of shunt resulted in complete resolution of symptoms. 2.5% (n = 3) had severe bilateral carotid stenosis and shunt was deployed. One of these patients developed stroke which was permanent. There was no mortality. The mean procedure time was 170 min in patients in whom shunt was used, when compared with 100 min in patients without shunt (P = 0.003). Conclusion: Use of shunt in carotid endarterectomy under local anesthesia as selective policy has an advantage in terms of cost effectiveness, operation time and prevention of potential complications.

Selective Patch Angioplasty and Intraoperative Shunting in Carotid Endarterectomy: A Single-Center Review of 141 Procedures.

Objective: Open surgical treatment of carotid artery stenosis, namely, carotid endarterectomy (CEA), has evolved since its inception in 1953. Despite improvements in the treatment of carotid occlusive disease through technological and surgical innovations, the use of patch grafting in CEA’s remains controversial. We evaluate the durability of the primary closure and the safety of selective shunting during carotid endarterectomy (CEA) as determined by intraoperative EEG and postoperative outcomes.Methods: A consecutive series of CEA’s performed by the senior author at a single academic medical center from 2001 to 2012 were reviewed. All cases were performed under continuous intraoperative electroencephalography (EEG). Patch angioplasty was used in cases where there was tortuosity of the vessel within the region of the endarterectomy and narrow vessel diameter at the distal end of the arteriotomy. Shunting was used when intraoperative EEG showed a > 50% reduction in a waveform in any lead. Patients were evaluated for restenosis via imaging or ultrasound at six months and subsequently annual follow-up.Results: One hundred and forty-one CEA’s were performed on 132 (76 male, 56 female) patients with an average age of 71 years (range: 40–95 years). Four (3%) cases required patch angioplasty and three (2%) required intraoperative shunts. The cross-clamp time ranged from 22 to 74 minutes, and the duration increased with the use of shunts and patches. Complications were rare and included recurrent stenosis (n=2), postoperative transient ischemic attack (n=1), ischemic stroke in (n=1), temporary hypoglossal nerve weakness (n=2), temporary marginal mandibular nerve weakness (n=6), and neck hematoma (n=1).Conclusion: Intraoperative EEG data suggests that primary closure and selective shunting in CEA can result in outcomes comparable with routine patch angioplasty and shunting.

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting).

Temporary interruption of cerebral blood flow during carotid endarterectomy can be avoided by using a shunt across the clamped section of the carotid artery. This may improve outcome. This is an update of a Cochrane review originally published in 1996 and previously updated in 2009. To assess the effect of routine versus selective or no shunting during carotid endarterectomy, and to assess the best method for selecting people for shunting. We searched the Cochrane Stroke Group Trials Register (last searched August 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2013, Issue 8), MEDLINE (1966 to August 2013), EMBASE (1980 to August 2013) and Index to Scientific and Technical Proceedings (1980 to August 2013). We handsearched journals and conference proceedings, checked reference lists, and contacted experts in the field. Randomised and quasi-randomised trials of routine shunting compared with no shunting or selective shunting, and trials that compared different shunting policies in people undergoing carotid endarterectomy. Three review authors independently performed the searches and applied the inclusion criteria. For this update, we identified two new relevant randomised controlled trials. We included six trials involving 1270 participants in the review: three trials involving 686 participants compared routine shunting with no shunting, one trial involving 200 participants compared routine shunting with selective shunting, one trial involving 253 participants compared selective shunting with and without near-infrared refractory spectroscopy monitoring, and the other trial involving 131 participants compared shunting with a combination of electroencephalographic and carotid pressure measurement with shunting by carotid pressure measurement alone. In general, reporting of methodology in the included studies was poor. For most studies, the blinding of outcome assessors and the report of prespecified outcomes were unclear. For routine versus no shunting, there was no significant difference in the rate of all stroke, ipsilateral stroke or death up to 30 days after surgery, although data were limited. No significant difference was found between the groups in terms of postoperative neurological deficit between selective shunting with and without near-infrared refractory spectroscopy monitoring, However, this analysis was inadequately powered to reliably detect the effect. There was no significant difference between the risk of ipsilateral stroke in participants selected for shunting with the combination of electroencephalographic and carotid pressure assessment compared with pressure assessment alone, although again the data were limited. This review concluded that the data available were too limited to either support or refute the use of routine or selective shunting in carotid endarterectomy. Large scale randomised trials of routine shunting versus selective shunting are required. No method of monitoring in selective shunting has been shown to produce better outcomes.

Risk Index for Predicting Shunt in Carotid Endarterectomy

To prevent ischemia during carotid endarterectomy, a routine or selective shunt can be set up in cases of insufficient cerebral perfusion during the carotid clamping. The aim of this study was to analyze predictive factors for shunting under locoregional anesthesia and to validate a risk index to predict shunt. Using a prospective database, we studied carotid endarterectomy performed under locoregional anesthesia between January 1, 2003, and December 31, 2010 (n=1,223). A shunt was used because of clinical intolerance of clamping in 88 cases (group S, 7.2%). Clinical, comorbidities, demographics, and duplex scan data were used to compare group S to a control group (group C, n=1,135, 92.8%). A multivariable logistic regression was performed to identify predictors of shunt. Coefficients were assigned to each predictor to propose a predictive score. Patients in group S were significantly older than those in group C (75.6±7.8 years vs. 72.6±9.4 years, P<0.001). Other factors associated with a carotid shunt were female sex (odds ratio [OR]=2.41, 95% confidence interval [CI]: 1.54-3.78, P<0.001), systemic arterial hypertension (OR=2.478, 95% CI: 1.16-4.46, P=0.016), occlusion of the contralateral carotid artery (OR=6.03, 95% CI: 2.91-12.48, P<0.001), and 1 factor against the likelihood of a carotid shunt, a history of contralateral carotid surgery (OR=0.34, 95% CI: 0.12-0.93, P=0.037). The mean flow in the contralateral common carotid artery was 696.5±298.0 mL/sec in group S and 814.7±285.5 mL/sec in group C (P<0.001). Using those 6 items, we propose a prognostic score validated in our series and allowing to divided risk of intolerance of clamping into low-risk (≤6%), intermediate-risk (6.1%-15%), and high-risk (>15%) groups. We have established the first version of a score that predicts the need for a shunt by studying factors associated with intolerance to clamping. The relevance of this score, validated in our series, must be confirmed and adjusted by studies based on a larger sample size.

Routine vs guided by NIRS selective shunting in carotid endarterectomy. A prospective, randomized, comparative study

Routine vs guided by NIRS selective shunting in carotid endarterectomy. A prospective, randomized, comparative study

Prospective randomized trial of routine versus selective shunting in carotid endarterectomy based on stump pressure

The use of shunting in carotid endarterectomy (CEA) is controversial. This randomized trial compared the results of routine (RS) vs selective shunting (SS) based on stump pressure (SP). Two-hundred CEA patients under general anesthesia were randomized into RS (98 patients) or SS (102 patients), where shunting was used only if systolic SP (SSP) was <40 mm Hg. Clinical and demographic characteristics were comparable in both groups. Patients underwent immediate and 30-day postoperative duplex ultrasound follow-up. Analysis was by intention-to-treat. Of 102 SS patients, 29 (28%) received shunting. Indications for CEA were similar (42% symptomatic for RS; 47% for SS, P = .458). The mean internal carotid artery diameter was comparable (5.5 vs 5.5 mm, P = .685). Mean preoperative ipsilateral and contralateral stenosis was 76% and 38% for RS (P = .268) vs 78% and 40% for SS (P = .528). Mean preoperative ipsilateral and contralateral stenosis was 79% and 56% in the shunted (P = .634) vs 78% and 34% in the nonshunted subgroup of SS patients (P = .002). The mean SSP was 55.9 mm Hg in RS vs 56.2 for SS (P = .915). The mean SSP was 33 mm Hg in the shunted vs 65 in the nonshunted subgroup (P < .0001). Mean clamp time in the nonshunted subgroup of SS was 32 minutes. Mean shunt time was 35 minutes in RS and 33 in SS (P = .354). Mean operative time was 113 minutes for RS and 109 for SS (P = .252), and 111 minutes in shunted and 108 in the nonshunted subgroup (P = .586). Mean arteriotomy length was 4.4 cm for RS and 4.2 for SS (P = .213). Perioperative stroke rate was 0% for RS vs 2% for SS (one major and one minor stroke, both related to carotid thrombosis; P = .498). No patients died perioperatively. Combined perioperative transient ischemic attack (TIA) and stroke rates were 2% in RS vs 2.9% in SS (P > .99). The overall perioperative complication rates were 8.3% in RS (2 TIA, 3 hemorrhage, 1 myocardial infarction [MI], and 1 asymptomatic carotid thrombosis) vs 7.8% in SS (2 strokes, 1 TIA, 3 hemorrhage, 1 MI, and 1 congestive heart failure; P = .917). RS and SS were associated with a low stroke rate. Both methods are acceptable, and surgeons should select the method with which they are more comfortable.

Prospective Randomized Trial of Routine vs Selective Shunting in Carotid Endarterectomy Based on Stump Pressure

Prospective Randomized Trial of Routine vs Selective Shunting in Carotid Endarterectomy Based on Stump Pressure

Extended BSI for continuous EEG monitoring in carotid endarterectomy

Objective Carotid endarterectomy is a common procedure as a secondary prevention of stroke, and is often performed with selective shunting. Although various EEG parameters have been proposed to determine if the brain is at risk during carotid artery clamping, the common procedure is still the visual assessment of the EEG. Here, we propose an extension to the previously described brain symmetry index (BSI) [van Putten M, Peters J, Mulder S, de Haas J, Bruijninckx C, Tavy D. A brain symmetry index (BSI) for online EEG monitoring in carotid endarterectomy. Clin Neurophysiol 2004, 115(5), 1189–94.], as an additional quantitative criterion for shunt need in carotid endarterectomy. Methods An extension of the Brain Symmetry Index was implemented to capture both spatial (hemispheric) (sBSI) and temporal changes (tBSI) in the EEG. In this pilot study, the method is exemplified by simulation and by application to EEG records from 25 patients who underwent a carotid endarterectomy. Results Simulations show that hemispheric asymmetry is captured by changes in sBSI, only, while temporal symmetry changes, not due to changes in hemispheric asymmetry, are reflected by changes in tBSI. Combinations of changes induced changes in both parameters. This was confirmed by analysis 25 EEG records. Unilateral EEG changes during test-clamping are reflected by ΔsBSI > 0.05, diffuse changes by ΔtBSI > 0.02 and combinations by simultaneous changes in both features. Conclusions In this pilot study, we present a doublet of quantitative EEG features, that in principle detects any change in the spectral characteristics of the EEG, decomposing the changes into a measure that captures spatial symmetry changes (sBSI), and a measure that quantifies diffuse temporal changes, that are not due to changes in spatial symmetry (tBSI). Both features are normalized with values ranging from [0–1], and can easily be implemented on-line to support the visual analysis of the EEG in the decision for selective shunting. Significance Quantitative real-time EEG analysis will assist in the EEG interpretation for selective shunting in carotid endarterectomy.

Cerebral oximetry changes during shunting in carotid endarterectomy

Zogogiannis, I.; Alevizou, A.; Kouskouri, A.; Alexopooulos, Ch.; Dimitriou, V. Author Information

Effect of carotid endarterectomy on cerebral blood flow and its response to hypercapnia.

Cerebral blood flow (CBF) was measured in 14 patients before carotid endarterectomy, 3 h after surgery and 2 days postoperatively using the intravenous xenon-133 technique. In 11 of the patients CBF was remeasured at 6 months and in 8 patients CBF and the response to hypercapnia (5 per cent CO2 in air) was measured pre-operatively and 6 months following surgery. All operations were performed using an intraluminal Javid shunt and internal carotid artery (ICA) 'stump' pressure was recorded. CBF measured at 3 h after endarterectomy revealed a postoperative cerebral hyperperfusion with significantly increased flows in both hemispheres. There was a significant correlation between carotid cross clamping time and ipsilateral hemispheric CBF increase which implied an ischaemic aetiology for the hyperperfusion and supported the routine use of an intraluminal shunt in carotid endarterectomy. Six months after surgery, CBF had returned to its preoperative value but reactivity to CO2 was significantly improved, which suggested that the operation had increased cerebral reserve.

Stump pressure and transcranial Doppler for predicting shunting in carotid endarterectomy

Objectives: to compare stump pressure (SP) and transcranial Doppler (TCD) with neurologic monitoring during carotid endarterectomy (CEA). Materials: one hundred and forty-seven CEAs performed under local anaesthesia. Methods: neurologic monitoring and SP were performed in all cases, while mean velocity of the middle cerebral artery (mvMCA) by TCD was done in 140/147 (95%) cases. Shunts were applied in all cases on the basis of neurologic monitoring. The following haemodynamic criteria have been compared to neurologic monitoring: (a) <25 mmHg SP; (b) <50 mmHg SP; (c) ≤10 cm/s mvMCA after carotid occlusion; (d) ≥70 decrease of mvMCA after carotid occlusion. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for each haemodynamic criterion. Results: shunt was used in 18/147 (12.2%) cases. With regards to <25 mmHg SP, ≤50 mmHg SP, ≤10 cm/s mvMCA after carotid occlusion, and ≥70 decrease of mvMCA after carotid occlusion, sensitivity resulted 33, 89, 80 and 80%, respectively. Specificity resulted 96, 82, 97 and 96%, respectively. Positive predictive value resulted 55, 41, 75 and 71%, respectively. Negative predictive value 91, 98, 98 and 98%, respectively. Accuracy resulted 88, 76, 89 and 94%, respectively. Conclusions: none of the haemodynamic criteria by SP and TCD resulted absolutely reliable in predicting the need for carotid shunt.Eur J Vasc Endovasc Surg 25, 164–167 (2003)