Does Intensive Management of Cerebral Hemodynamics and Atheromatous Aorta Reduce Stroke After Coronary Artery Surgery?

Intracranial Atherosclerosis Increases the Risk of Postoperative Stroke After Cardiac Surgery: A Review and Meta-Analysis

BACKGROUND

Postoperative stroke is a devastating complication of cardiac surgery with high morbidity, mortality, and health care cost. Extracranial carotid atherosclerosis (ECAS) is a known risk factor for stroke; however, the impact of intracranial atherosclerosis (ICAS) remains unclear. To our knowledge, this is the first literature review of ICAS in cardiac surgery. We aimed to assess the prevalence, association with postoperative stroke, and perioperative management of ICAS in cardiac surgery.

METHOD

A search was performed to identify studies reporting rates of ICAS and stroke after cardiac surgery. Data extraction and primary outcomes for meta-analysis included the prevalence of preoperative ICAS and the association between ICAS and stroke. Risk ratios (RRs) and 95% confidence intervals (CIs) were pooled by random-effects modelling.

RESULTS

Seventeen studies were reviewed and seven were included in the meta-analysis, comprising 4,936 patients. Prevalence of intracranial atherosclerosis (ICAS) among cardiac surgery patients was 21% (95% CI 13%-32%). Patients with ICAS were more likely to develop postoperative stroke (RR 3.61; 95% CI 2.30-5.67; p<0.001). ICAS was more closely associated with stroke than ECAS. Preoperative brain perfusion single-photon emission computed tomography with acetazolamide challenge, staged intracerebral revascularisation, or conversion to off-pump coronary artery bypass grafting are described management options for ICAS.

CONCLUSION

Patients with ICAS are 3.61 times more likely to develop stroke after cardiac surgery. Known predictors for ICAS can be used to develop risk stratification screening tools. Further research with diverse cohorts is required to develop evidence-based guidelines for screening and management of ICAS in cardiac surgery.

The Rationalisation of Intra-Operative Imaging During Cardiac Surgery: A Systematic Review

INTRODUCTION

One critical complication of cardiac surgery is cerebrovascular accidents (CVAs). Ascending aorta atherosclerosis poses a significant risk of embolisation to distal vessels and to cerebral arteries. Epi-aortic ultrasonography (EUS) is thought to offer a safe, high-quality accurate visualisation of the diseased aorta to guide the surgeon on the best surgical approach to the planned procedure and potentially improve neurological outcomes post-cardiac surgery.

METHOD

The authors conducted a comprehensive search of PubMed, Scopus and Embase. Studies that reported on epi-aortic ultrasound use in cardiac surgery were included. Major exclusion criteria were: (1) abstracts, conference presentations, editorials, literature reviews; (2) case series with <5 participants; (3) epi-aortic ultrasound in trauma or other surgeries.

RESULTS

A total of 59 studies and 48,255 patients were included in this review. Out of the studies that reported patient co-morbidities prior to cardiac surgery, 31.6% had diabetes, 59.5% had hyperlipidaemia and 66.1% had a diagnosis of hypertension. Of those that reported significant ascending aorta atherosclerosis found on EUS, this ranged from 8.3% of patients to 95.2% with a mean percentage of 37.8%. Hospital mortality ranged from 7% to 13%; four studies reported zero deaths. Long-term mortality and stroke rate varied significantly with hospital duration.

CONCLUSION

Current data have shown EUS to have superiority over manual palpation and transoesophageal echocardiography in the prevention of CVAs following cardiac surgery. Yet, EUS has not been implemented as a routine standard of care. Extensive adoption of EUS in clinical practice is warranted to aid large, randomised trials before making prospective conclusions on the efficacy of this screening method.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Volatile and Intravenous Anesthetics for Brain Protection in Cardiac Surgery: Does the Choice of Anesthesia Matter?

Postoperative neurologic complications have a significant effect on morbidity, mortality, and long-term disability in patients undergoing cardiac surgery. The etiology of brain injury in patients undergoing cardiac surgery is multifactorial and remains unclear. There are several perioperative causative factors for neurologic complications, including microembolization, hypoperfusion, and systemic inflammatory response syndrome. Despite technologic advances and the development of new anesthetic drugs, there remains a high rate of postoperative neurologic complications. Moreover, despite the strong evidence that volatile anesthesia exerts cardioprotective effects in patients undergoing cardiac surgery, the neuroprotective effects of volatile agents remain unclear. Several studies have reported an association of using volatile anesthetics with improvement of biochemical markers of brain injury and postoperative neurocognitive function. However, there is a need for additional studies to define the optimal anesthetic drug for protecting the brain in patients undergoing cardiac surgery.

Timing of Recognition for Perioperative Strokes Following Cardiac Surgery

INTRODUCTION

More than half of reported perioperative strokes following cardiac surgery are identified beyond postoperative day one. The objective of our study was to determine preoperative and intraoperative factors that are associated with stroke following cardiac surgery and to identify factors that may contribute delayed recognition of perioperative stroke.

METHODS

Patients undergoing coronary artery bypass surgery or isolated valve surgery from January 2, 2015 to April 28, 2017 at an academic health system were identified from the Society of Thoracic Surgeons Registry. We determined preoperative and intraoperative factors associated with perioperative stroke. Two neurologists performed retrospective chart reviews on perioperative stroke patients to determine the last seen well time and the stroke cause.

RESULTS

During the study period, 2795 patients underwent coronary artery bypass surgery or isolated valve surgery (mean age 64 ± 11 years, 71% male, 72% Caucasian, 9% history of stroke), of which 43 (1.5%) had a perioperative stroke; 31 (72%) patients had an embolic mechanism of stroke based on neuroimaging. In multivariable analysis, perioperative strokes were independently associated with increasing age (OR 1.04, 95% 1.01-1.07), history of stroke (OR 2.73, 95% CI 1.47-5.06), and history of thoracic aorta disease (OR 3.36, 95% CI 1.16-9.71). Strokes were identified after postoperative day one in 32 (74%) patients of which 26 (81%) had a preoperative last seen well time.

CONCLUSION

Given the high frequency of preoperative last seen well time in perioperative stroke patients who are identified after postoperative day one, delayed stroke recognition may contribute to the bimodal distribution in timing of perioperative stroke. Frequent neurological monitoring within 24 hours after CABG or isolated valve surgery should be considered for all patients undergoing cardiac surgery, particularly elderly patients and those with a history of stroke or thoracic aorta disease, to improve early stroke recognition.

Coronary artery bypass grafting and perioperative stroke: imaging of atherosclerotic plaques in the ascending aorta with ungated high-pitch CT-angiography

Perioperative stroke is a devastating complication after coronary artery bypass graft (CABG) surgery, with atherosclerosis of the ascending aorta as important risk factor. During surgical manipulation, detachment of plaques can lead to consecutive embolization into brain-supplying arteries. High-pitch computed tomography angiography (HP-CTA) represents a non-invasive imaging modality, which provides the opportunity for comprehensive imaging of the ascending aorta, including plaque detection and advanced characterization. In our present retrospective study on 719 individuals, who had undergone HP-CTA within 6 months prior to CABG, atherosclerotic disease of the ascending aorta was evaluated with respect to perioperative stroke rates. For image analysis, the ascending aorta was divided into a proximal and distal part, consisting of four segments, and evaluated for presence and distribution of calcified and mixed plaques. All patients with perioperative stroke presented with atherosclerotic disease of the ascending aorta. The stroke rate was significantly associated with the presence and extent of atherosclerotic disease. Patients burdened with mixed plaques presented with significantly higher perioperative stroke rates. This study demonstrates that HP-CTA allows accurate evaluation of plaque extent and composition in the ascending aorta, and therefore may improve risk stratification of stroke prior to CABG.

Clinical outcomes of automated anastomotic devices: A metanalysis

Background and Aims

We investigated neurological events, graft patency, major adverse cardiovascular events (MACEs), and mortality at 1 year following coronary artery bypass grafting (CABG) surgery using automated proximal anastomotic devices (APADs) and compared the overall rates with the current literature.

Methods

A systematic review of all available reports of APADs use in the literature was conducted. Cumulative incidence and 95% confidence interval (CI) were the main statistical indexes. Nine observational studies encompassing a total of 718 patients were included at the end of the selection process.

Results

The cumulative event rate of neurological complications was 4.8% (lower‐upper limits: 2.8‐8.0, P < .001; I² = 72.907%, P = .002; Egger's test: intercept = –2.47, P = 0.16; Begg and Mazumdar test: τ = −0.20, p = 0.57). Graft patency was 90.5% (80.4 to 95.7, P < .001; I² = 76.823%, P = .005; Egger's test: intercept = –3.04, P = .10; Begg and Mazumdar test: τ = −0.67, P = .17). Furthermore, the overall incidence of MACEs was 3.7% (1.3‐10.4, P < .001; I² = 51.556%, P = .103; Egger's test: intercept = –1.98, P =  < .11; Begg and Mazumdar test: τ = −0.67, P = .17). Finally, mortality within 1 year was 5% (3.5‐7, P < .001; I² = 29.675%, P = .202; Egger's test: intercept = –0.91, P = .62; Begg and Mazumdar test: τ = −0.04, P = .88).

Conclusions

APADs do not seem to be correlated with a reduction of either neurological events or mortality. By contrast, these tools showed satisfactory one‐year graft patency and a low incidence of MACEs. Further research on this topic is warranted.

A functional evaluation of cerebral perfusion for coronary artery bypass grafting patients

We evaluate the utility of providing a pulsatile blood flow by applying off-pump coronary artery bypass grafting (CABG) or intra-aortic balloon pumping (IABP) with conventional CABG to prevent perioperative stroke in patients with cerebral hypoperfusion on single-photon emission-computed tomography (SPECT). A total of 286 patients underwent isolated CABG with a cerebral magnetic resonance angiography (MRA) evaluation between 2006 and 2015. Seventy-five had significant stenosis and/or occlusion of craniocervical vessels; the other 211 had no significant stenosis. Cerebral SPECT was performed for 49 (SPECT group) of the 75 patients. The SPECT group was further divided into a normal perfusion (NP) (n = 37); and a hypoperfusion (HP) (n = 12). In the present study we compared the NP group and the 211 patients with no significant stenosis (as a control group) to the HP group. No strokes occurred in the HP group, and 1 stroke occurred at the time of operation in the control group. Postoperative stroke within 30 days occurred in 3 patients in the control group; the difference was not statistically significant. The long-term stroke-free rates of the HP and Control group did not differ to a statistically significant extent. The functional evaluation of cerebral perfusion by SPECT is important when patients have significant stenotic lesions on cerebral MRA. Maintaining an adequate pulsatile flow by off-pump CABG or IABP with conventional CABG will help prevent perioperative stroke, even if cerebral hypoperfusion is detected by SPECT.

Impact of the Haga Braincare Strategy on the burden of haemodynamic and embolic strokes related to cardiac surgery

OBJECTIVES

This study prospectively evaluates the impact of the Haga Braincare Strategy (HBS) on the occurrence of haemodynamic and embolic stroke in a cohort of patients who underwent coronay artery bypass grafting (CABG), valve replacement of a combination of both types of surgery between 2012 and 2015 at the Haga Teaching Hospitals.

METHODS

The HBS is a dual strategy based on a preoperative vascular work-up of the cerebral circulation by transcranial Doppler and a perioperative monitoring of the cerebral circulation by cerebral oximetry. Duplex of the carotid arteries and/or computed tomography angiography prior to surgery was performed in high-risk patients. Patients with severe carotid artery stenosis were scheduled for carotid angioplasty prior to surgery or waived from surgery.

RESULTS

A total of 1065 patients were included. Poor cerebral haemodynamics were identified by transcranial Doppler in 2.1% of patients (n = 22). Based on the HBS, 3 patients were waived from surgery, 4 received preoperative carotid angioplasty followed by cardiac surgery and the remaining patients were operated while being monitored with bilateral cerebral oximetry sensors. In all, 2.2% of the study group experienced a stroke (n = 23), of which none were classified as haemodynamic. Most of the remaining presumed embolic strokes showed a minor to moderate stroke severity.

CONCLUSIONS

In this single-centre prospective follow-up study, surveillance of cerebral perfusion by the HBS eliminated the occurrence of haemodynamic stroke while most of the residual strokes had a good to favourable prognosis.

Internal Carotid Artery Occlusion: Pathophysiology, Diagnosis, and Management

PURPOSE OF REVIEW

Acute internal carotid artery occlusion (ICAO) is associated with large infarcts and poor clinical outcomes and contributes to morbidity and mortality worldwide. In this review, we discuss various etiologies and pathophysiology of clinical presentations of ICAO, different radiographic patterns, and management of patients with ICAO.

RECENT FINDINGS

Recanalization rates remain suboptimal with systemic thrombolysis amongst patients with acute ICAO. Recent success of endovascular therapy for vessel occlusion in anterior circulation has expanded the horizons; however, few patients with cervical dissections and ICAO were included in these landmark trials. Acute ICAO responds poorly to intravenous thrombolysis and portends worse clinical outcomes. Extracranial and intracranial ICAOs have varied clinical course and imaging patterns, with discrete cervical ICAO usually associated with better clinical outcomes while tandem occlusions predispose poor outcomes. Diagnostic catheter-based angiogram is often required since appearances of ICAO using non-invasive neuroimaging modalities are often deceiving. Repeated vascular imaging in acute to subacute phase to determine recanalization of ICAO is critical for secondary prevention. Recent success of endovascular procedures will continue to expand the horizons to improve the management of ICAO.

A Protocol for Diagnosis and Management of Aortic Atherosclerosis in Cardiac Surgery Patients

In patients undergoing cardiac surgery, use of perioperative screening for aortic atherosclerosis with modified TEE (A-View method) was associated with lower postoperative mortality, but not stroke, as compared to patients operated on without such screening. At the time of clinical implementation and validation, we did not yet standardize the indications for modified TEE and the changes in patient management in the presence of aortic atherosclerosis. Therefore, we designed a protocol, which combined the diagnosis of atherosclerosis of thoracic aorta and the subsequent considerations with respect to the intraoperative management and provides a systematic approach to reduce the risk of cerebral complications.

Increasing severity of aortic atherosclerosis in coronary artery bypass grafting patients evaluated by transesophageal echocardiography

Background

Atherosclerotic disease in coronary artery bypass grafting (CABG) patients is a potential contributor to complications in the perioperative periods. This study was undertaken to better define how the frequency of aortic atheromatous disease among patients coming for CABG has evolved over the last decade.

Methods

Data from elective patients coming for CABG who underwent transesophageal echocardiography (TEE) examinations following induction of anesthesia were obtained for the years 2002 and 2009. Aortas were graded according to the method of Kronzon, with the following interpretations: normal = grade I, intimal thickening = 2, atheroma of less than 5 mm = 3, atheroma of > 5 mm = 4, and any mobile atheroma = 5. The data of 124 patients who underwent comprehensive exam of the aorta by one cardiac anesthesiologist were gathered and assigned into two groups based on the year TEE was done. Student’s t-test was used for statistical analysis. A P value < 0.05 was considered significant. The data were presented as mean ± SD.

Results

There was significant difference between group 2002 (2.05 ± 1.28) and group 2009 (2.59 ± 1.11) in atheroma grade (P = 0.013).

Conclusions

Patients coming for CABG in group 2009 exhibited significantly higher grades of aortic atheroma on TEE, compared to group 2002. Understanding the risk of atheroma in the elderly CABG population may help in altering surgical approaches to lessen the risk of catastrophic stroke. Potential options needing further study include the off-pump approach and modification of cross-clamp site and technique as well as other modalities.

Perioperative management of combined carotid and coronary artery bypass grafting procedures

The objective of this review is to provide a high level overview on current thinking for treatment of patients with combined carotid and coronary artery disease given that these patients are at higher risk of adverse cardiac events, stroke, and death. This review discusses (1) the current literature addressing perioperative stroke risk in the setting of coronary artery bypass graft, (2) the literature regarding different surgical approaches when both carotid and coronary revascularization are being considered, and (3) the data available to guide optimal management of this complex patient population to minimize complications regardless of the surgical approach taken.

Asymptomatic carotid stenosis: immediate revascularization or watchful waiting?

Based on several randomized clinical trials, carotid revascularization has been shown to reduce future stroke risk among individuals with severe asymptomatic carotid stenosis. However, a well-recognized problem with such prophylactic intervention is the risk of periprocedural stroke, death, or myocardial infarction. If actual stroke risk with asymptomatic carotid stenosis can be reduced significantly by aggressive medical management, carotid revascularization may yield marginal benefit or even cause harm especially in those with limited life expectancy. Based on recent observational data, it is becoming apparent that the stroke risk in this population has been declining with better medical management alone. This has prompted a few to avoid carotid revascularization for asymptomatic carotid stenosis altogether. Others feel such conclusions cannot be made with observational data alone. In the midst of this controversy, it is important that clinicians perform carotid revascularization on a case by case basis while ensuring optimal medical management in all patients. An algorithmic approach to decision making based on available evidence will enable clinicians to personalize patient management with efficiency.

Carotid Artery Stenosis Associated with Increased Mortality in Patients who Underwent Coronary Artery Bypass Grafting: A Single Center Experience

BACKGROUND

Vascular disease resulting from arteriosclerosis is a severe worldwide health risk. Early diagnosis and intervention is important to control adverse cerebral and cardiovascular events. The aim of this study was to assess the potential predictors of mortality in patients submitted to coronary bypass surgery.

METHODS

Cohort study included asymptomatic cerebrovascular disease patients scheduled for coronary artery bypass grafting admitted to the cardiology reference center. All patients were submitted to carotid artery ultrasound assessment prior to surgery and were followed up during the entire in-hospital postoperative period. Carotid artery stenosis was considered clinically significant when cross sectional area ≥50%. Significance was set at p <0.05. Logistic regression was used to identify independent predictors of mortality.

RESULTS

Of 455 patients with a mean age of 62.2 years 65.6% were males. The prevalence of carotid artery stenosis was 18.7%. It was absent in 3.6% of the patients, below 50% in 77.8%, between 50 and 69% in 11.6%, and between 70 and 99% in 6.9%. The carotid artery was occluded in 0.2% of the sample. An overall mortality of 12%, affecting 35 men (P=0.001) with stenosis ≥50%. After logistic regression analysis, carotid artery stenosis ≥50% was confirmed as being an independent predictor of mortality (P=0.005).

CONCLUSION

In this series carotid artery stenosis showed a high prevalence in the sample assessed and was an independent predictor of mortality.

Stroke risk after coronary artery bypass graft surgery and extent of cerebral artery atherosclerosis

OBJECTIVES

We aimed to define the relationship between cerebral atherosclerosis and stroke after coronary artery bypass grafting (CABG).

BACKGROUND

Although cerebral atherosclerosis may play a crucial role in the advent of post-CABG stroke, only extracranial carotid artery disease has been extensively studied, and the effects of atherosclerosis on the mechanisms underlying post-CABG stroke remain unclear.

METHODS

Pre-operative magnetic resonance angiography was performed on 1,367 consecutive CABG patients to assess intracranial and extracranial cerebral atherosclerosis. Disease severity was evaluated by atherosclerosis score, as determined by the number of steno-occlusions of cerebral arteries and the degree thereof. Post-CABG strokes (within 14 days) were classified as atherosclerotic (strokes attributable to pre-defined atherosclerosis) or other (strokes caused by other mechanisms). Associations between post-CABG stroke and each type of atherosclerotic disease (extracranial carotid artery disease, intracranial, extracranial, or extracranial and/or intracranial cerebral atherosclerosis), differentiated according to the involved arteries, were analyzed.

RESULTS

Stroke occurred in 33 patients, and the atherosclerosis score was independently associated with stroke development (odds ratio: 1.35; 95% confidence interval: 1.16 to 1.56). Atherosclerotic stroke was defined in 15 (45%), and constituted >40% of both immediate (within 24 h) and delayed strokes. Intracranial, extracranial, and extracranial and/or intracranial cerebral atherosclerosis were significantly associated with stroke.

CONCLUSIONS

Cerebral atherosclerosis was closely related to the occurrence of post-CABG stroke, being both an independent risk factor for and the cause of a significant proportion of strokes. Pre-operative evaluation of intracranial and extracranial cerebral arteries, apart from the extracranial carotid artery, may be useful to predict the likelihood of post-CABG stroke.

Is carotid artery disease responsible for perioperative strokes after coronary artery bypass surgery?

The coronary and extracranial carotid vascular beds are often simultaneously affected by significant atherosclerotic disease, and stroke is one of the potential major complications of coronary artery surgery. As a result, there is no shortage of reports in the vascular surgery literature describing simultaneous coronary and carotid artery revascularizations. Generally, these reports have found this combination of operations safe, but have stopped short of proving that it is necessary. Intuitively, simultaneous carotid endarterectomy and coronary artery bypass surgery could be justified if most perioperative strokes were the result of a significant carotid stenosis, either directly or indirectly. At first glance this appears to be a fairly straightforward issue; however, much of the evidence on both sides of the argument is circumstantial. One significant problem in analyzing outcome by choice of treatment in patients presenting with both coronary and carotid disease is the multiple potential causes of stroke in coronary bypass patients, which include hemorrhage and atheroemboli from aortic atheromas during clamping. But this controversial subject is now open to discussion, and our debaters have been given the challenge to clarify the evidence to justify their claims.

Improve morbidity and mortality in coronary artery bypass graft surgery for severe atherosclerosis

OBJECTIVES

Atherosclerosis has been identified as a risk factor for both morbidity and mortality in patients undergoing coronary artery bypass grafting (CABG). To investigate outcomes following CABG for severe atherosclerosis, and to determine whether different surgical techniques can reduce the risk of neurologic events in these patients.

METHODS

We studied 225 consecutive patients who underwent elective isolated CABG. Routine preoperative and intraoperative examinations identified patients with severe atherosclerosis. We compared the outcomes between patients with (group A; 42 ceses) and those without (group N; 183 cases) severe atherosclerosis.

RESULTS

36 patients (85.7%) in group A and 176 (96.2%) in group N underwent off-pump coronary artery bypass (OPCAB); 6 (14.3%) in group A and 7 (3.8%) in group N underwent on-pump beating CABG. Three patients in group A suffered deep sternal infection (7.1%), and one suffered stroke (2.4%) compared with none in group N. No cerebral infarction or neurologic events occurred in patients who underwent OPCAB (n = 212, 94.2%).

CONCLUSIONS

Prevalence of complications was significantly greater among patients with severe atherosclerotic disease who underwent OPCAB than in those without atherosclerotic disease. Careful selection of surgical strategies can prevent perioperative stroke and reduce mortality.

Neurologic complications of cardiac surgery and interventional cardiac procedures

Neurologic complications of cardiac surgery and interventional cardiac procedures may affect the central nervous system or the peripheral nervous system. The most common central nervous system complications are strokes and seizures. This article provides a succinct neuroanatomic and pathophysiologic approach to a wide array of neurologic complications associated with cardiac procedures.

Therapeutic strategies for patients with internal carotid or middle cerebral artery occlusion complicated by severe coronary artery disease

BACKGROUND/OBJECTIVES

Ischemic stroke is one of major complications of cardiac surgery. Although a current American Heart Association (AHA) guideline states that carotid endarterectomy is probably recommended before or concomitant to coronary artery bypass grafting (CABG) for the carotid stenosis, there is no report that analyzed optimal strategies in cardiac surgery for patients with total occlusion of the internal carotid artery (ICA) or the middle cerebral artery (MCA). Therefore, this preliminary study was aimed to clarify whether preoperative blood flow measurements and prophylactic superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis could reduce the incidence of perioperative ischemic stroke during cardiac surgery in patients with total occlusion of the ICA or MCA.

METHODS

This prospective study included eight patients who were admitted to undergo cardiac surgery including CABG. All of them had total ICA or MCA occlusion on preoperative magnetic resonance (MR) examinations. Preoperative cerebral blood flow and its reactivity to acetazolamide were quantitatively determined in all eight patients using single photon emission computed tomography or positron emission tomography.

RESULTS

Preoperative blood flow measurements revealed that two (25%) of eight patients had normal cerebral hemodynamics because of well-developed collaterals. They safely underwent cardiac surgery. However, a marked impairment of cerebral perfusion reserve was identified in six (75%) of eight patients in the ipsilateral hemispheres. Of these, four patients underwent prophylactic STA-MCA anastomosis prior to CABG. Subsequently, they safely underwent CABG without perioperative ischemic stroke.

CONCLUSION

This is the first report suggesting that preoperative identification of hemodynamic compromise and prophylactic STA-MCA anastomosis may reduce perioperative ischemic stroke during cardiac surgery in patients with ICA or MCA occlusion, although further studies are needed to assess the validity.

Minimizing the risk of perioperative stroke by clampless off-pump bypass surgery: a retrospective observational analysis

Objectives

Stroke is a devastating complication after coronary artery bypass grafting, occurring in 1.4% to 4.3% of patients. A major cause of stroke is cerebral embolization of aortic atheromatous debris or calcified plaques. This report analyzes the incidence of stroke in patients treated according to the clampless concept, i.e. avoiding side-clamping of the aorta, by means of off-pump coronary artery bypass surgery (OPCAB) in combination with the HEARTSTRING device.

Methods

During a period of 43 months (2005-2008), 412 consecutive patients were treated with the above-mentioned method by one single surgeon. A minimum of one proximal aortal anastomosis was performed in each patient. Altogether, 542 proximal anastomosis were applied, each created by means of the HEARTSTRING device.

Results

The mean age of patients was 67+9.7 years, the predicted mortality 5.2% (logistic EuroSCORE) and the observed mortality 1.9%. Histories of preoperative neurological disorders or cerebrovascular diseases were documented in 15% of patients. The overall incidence of postoperative stroke was 0.48% in contrast to 1.3% according to the stroke risk score.

Conclusions

In accordance to previously published data, our results show that avoiding aortic side-clamping during OPCAB reduces postoperative stroke rates. The HEARTSTRING device is a safe option for creating proximal aortic anastomosis.

Known knowns, known unknowns and unknown unknowns: a 2010 update on carotid artery disease

The management of carotid artery disease never ceases to attract controversy. The last 12 months has seen publication of a number of important studies which have informed debate and 2010 holds the prospect of much more. This update offers a personal review of a number of contemporary issues including; (i) guidelines for non-invasive imaging in rapid access clinics, (ii) whether improvements in best medical therapy have rendered many of the conclusions from ACAS and ACST obsolete, (iii) is carotid disease really just a marker for increased stroke risk following cardiac surgery (rather than being an important cause), (iv) what is the current status of endarterectomy and stenting in patients with symptomatic carotid disease and (v) why we must offer expedited interventions to TIA/minor stroke patients. The available evidence suggests that while most 'known knowns' will endure, quite a few may be returning to the category of 'known unknowns' once again. Who knows what 'unknown unknowns' await us in 2010 and beyond.

Patients undergoing cardiac surgery with asymptomatic unilateral carotid stenoses have a low risk of peri-operative stroke

BACKGROUND

There is considerable controversy regarding the optimal management of patients undergoing cardiac surgery who are found to have an asymptomatic, unilateral carotid artery stenosis. Prior to 2004, the policy of this Unit was to perform a synchronous cardiac and carotid revascularisation. After January 2004, the policy was changed and patients underwent their cardiac procedure without carotid revascularisation. The aim of this study was to audit the incidence of stroke in the peri-operative period following this change in practice.

METHODS

Five-year audit of the 30-day risk of stroke after 61 consecutive open cardiac procedures in patients with unilateral, asymptomatic 70-99% (NASCET) stenoses who did not undergo prophylactic carotid endarterectomy.

RESULTS

61 cardiac procedures; coronary artery bypass grafting (CABG)=44, valve replacement=6, CABG+valve replacement=9, CABG+repair of left ventricular aneurysm=2 were undertaken and the 30-day outcomes audited. There were three deaths (4.9%), all due to myocardial infarction. No strokes occurred in any patient in the 30-day post-operative period.

CONCLUSION

These results challenge the opinion that the presence of a unilateral, asymptomatic carotid stenosis in patients undergoing open cardiac surgery is associated with an increased risk of peri-operative stroke, sufficient to warrant routine prophylactic carotid revascularisation.

Asymptomatic severe carotid stenosis undergoing staged carotid artery stent and coronary artery bypass grafting: decisive role of brain single photon emission computed tomography

Effort angina of a 70-year-old man was diagnosed as due to triple coronary vessel disease, and he was scheduled to undergo coronary artery bypass surgery. Preoperative carotid duplex scan revealed more than 75% stenosis of the right internal carotid artery, which was functionally proven to be significantly ischemic on brain single photon emission computed tomography. Although he was neurologically asymptomatic, we chose staged surgery for fear of stroke during coronary artery bypass surgery. He had successful carotid artery stenting first by neurosurgeons; then, 2 months later he underwent uneventful coronary artery bypass surgery. This experience prompted us to report the case.