The incidence of major neurologic complications in

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1 CURRENT REVIEW Coronary Artery Bypass Grafting in Patients With Cerebrovascular Disease Harold L. Lazar, MD, and James O. Menzoian, MD Department of Cardiothoracic Surgery and Section of Vascular Surgery, Boston University School of Medicine and Boston Medical Center, Boston, Massachusetts The incidence of carotid artery disease in patients undergoing coronary artery bypass grafting appears to be increasing as our population ages. The optimal treatment for these high-risk patients with concomitant carotid and coronary artery disease remains controversial. This review focuses on the management of patients with coexistent carotid and coronary arteriosclerosis. The significance and management of the patient with an asymptomatic carotid stenosis in patients undergoing coronary artery bypass grafting and the role of combined coronary artery bypass grafting and carotid endarterectomy in these patients will be discussed. (Ann Thorac Surg 1998;66:968 74) 1998 by The Society of Thoracic Surgeons Address reprint requests to Dr Lazar, Department of Cardiothoracic Surgery, Boston Medical Center, B402, 88 E Newton St, Boston, MA The incidence of major neurologic complications in patients undergoing coronary artery bypass grafting (CABG) ranges from 1% to 6% [1 3]. The causes of these perioperative neurologic deficits are multifactorial and include cerebral hypoperfusion, embolization of either air or atheromatous material, and the presence of extracranial carotid artery disease [4, 5]. Gardner and coworkers [1] noted that whereas operative mortality for CABG fell from 3.9% to 2.6% from 1974 to 1983, the incidence of perioperative strokes increased from 0.5% to 2.4% during the same period and was accompanied by an increase in age and the presence of preexisting cerebrovascular disease. Patients with concomitant cerebrovascular and coronary artery disease represent a subset of patients with advanced arteriosclerosis, not only in the coronary and cerebrovascular systems, but also in other areas of the arterial system. They have a higher incidence of left main coronary artery disease and reduced ejection fraction than is seen in patients with isolated coronary artery disease [4 8]. Furthermore, their cardiovascular disease is more extensive and carries a higher risk or perioperative stroke [3, 4]. Patients with severe coexistent carotid and coronary arteriosclerosis represent a difficult, high-risk population, and controversy exists regarding the optimal method of surgical management. Is there a role for simultaneous carotid endarterectomy (CEA) and CABG? Will simultaneous CEA and CABG protect patients from postoperative neurologic complications? If there is a role for combined CEA and CABG, which patients are candidates for this combined procedure? Finally, is there any evidence that combined CEA and CABG will result in any long-term protection from strokes? In this review, we will attempt to describe the various management options for these patients and to determine what operative strategies will result in the lowest operative morbidity and mortality. Incidence of Carotid Artery Stenosis in Patients Undergoing Coronary Artery Bypass Grafting The incidence of carotid artery disease in patients undergoing CABG varies from 2% to 22%, but appears to average 8% [2, 4, 7, 9 13]. This variation in the incidence of carotid artery disease is related to the methods of screening, how frequently they are used, and the definition of a significant stenosis. Balderman and coworkers [9] screened 500 CABG patients for preoperative carotid artery disease using ocular pneumoplethysmography (OPG). Although 32 patients had carotid artery bruits, only 9 had an abnormal OPG. The presence or absence of a bruit is an unreliable method of determining the severity of carotid artery occlusive disease. In the 9 patients with an abnormal OPG, only 6 had a greater than 50% carotid artery stenosis confirmed by angiography. The OPG measures ophthalmic artery pressure, which is the first branch of the internal carotid artery. This measurement is a composite of the pressure of the internal carotid artery distal to the stenosis and the pressure of the blood flow from the extracranial and intracerebral collaterals. Although a negative OPG does not require any further workup, a positive OPG in a patient considered to be a candidate for a CEA will need an angiogram to further delineate the stenosis. A more frequently used noninvasive technique to assess the significance of a carotid artery bruit is ultrasonic carotid artery duplex scanning. This technique combines real-time B-mode imaging and a single-gated pulsed Doppler system. Roederer and coworkers [14] have found that ultrasonic carotid artery duplex scanning yields a sensitivity of 99% and a specificity of 84% when compared with conventional angiography studies. Wareing and coworkers [15] found that 4.1% of CABG patients had an equal to or greater than 80% carotid artery 1998 by The Society of Thoracic Surgeons /98/$19.00 Published by Elsevier Science Inc PII S (98)

2 Ann Thorac Surg REVIEW LAZAR AND MENZOIAN 1998;66: CABG AND CEREBROVASCULAR DISEASE 969 stenosis as measured by duplex scanning. The incidence of carotid artery disease in CABG patients also appears to increase with age. Faggioli and coauthors [16] documented an increased prevalence of carotid artery disease related to age, with 8.7% of CABG patients age 60 years or older having an equal to or greater than 75% carotid artery stenosis. D Agostino and associates [17] report that clinical predictors of significant carotid artery stenosis in CABG patients are age, diabetes, female sex, left main coronary artery stenosis equal to or greater than 60%, prior stroke or transient ischemic attack (TIA), prior vascular operation, and smoking. Significance of an Asymptomatic Carotid Artery Stenosis During Coronary Artery Bypass Grafting Should CEA be recommended for all patients with carotid artery stenosis in the absence of neurologic symptoms? Balderman and colleagues [9] found that patients with carotid artery bruits and insignificant hemodynamic carotid artery disease, as determined by OPG measurements, did not have an increased incidence of perioperative strokes during CABG. In a series of 245 elective CABG patients, Bull and associates [2] detected an asymptomatic carotid artery stenosis equal to or greater than 60% in 26 patients (11%). The presence of a significant carotid artery stenosis did not correlate with a postoperative cerebrovascular accident (CVA). Ivey and coworkers [10] studied 82 patients with asymptomatic carotid artery bruits undergoing CABG operation. Using ultrasonic carotid artery duplex scanning, they found that 16 patients had lesions equal to or greater than 50%, and 66 had lesions less than or equal to 50%. None of the 82 patients had any focal neurologic events. In an attempt to assess the natural history of carotid artery stenosis in patients undergoing CABG, Schwartz and coworkers [4] obtained carotid artery Doppler studies in 582 patients. The overall incidence of significant carotid artery stenosis ( 50%) was 22%. A perioperative stroke developed in 6.2% of patients. No patient with a carotid artery stenosis between 50% and 79% had a CVA in this series. These studies suggest that asymptomatic patients with significant unilateral carotid artery stenoses do not appear to be at an increased risk to experience a perioperative CVA during CABG. Which groups of patients with carotid artery disease appear to be at a higher risk of the development of neurologic events? Schwartz and coworkers [4] found that patients with (1) 80% to 99% unilateral carotid artery stenosis, (2) bilateral stenosis of at least 50%, and (3) a unilateral total occlusion combined with at least 50% carotid artery lesion on the contralateral side had a higher incidence of perioperative CVAs ( 5%). The highest incidence was found in patients with at least 50% bilateral carotid artery stenosis (8.6%). Mehigan and coworkers [5] also noted that CABG patients with asymptomatic bilateral carotid artery stenoses were at increased risk for perioperative strokes. The incidence of neurologic events in patients with previously completed strokes undergoing CABG was studied by Beall and coworkers [18]. Patients with a completed CVA without active symptoms and without any evidence of extracranial disease had no increased incidence of neurologic events after CABG. Gerraty and coworkers [19] report that 53 patients with asymptomatic carotid artery stenosis of at least 50% were not at risk for stroke with CABG but that the risk of perioperative stroke was 8.2% in 49 symptomatic patients undergoing CABG. Although it appears that the majority of asymptomatic carotid artery lesions do not result in a perioperative neurologic event [17, 19], this does not mean that an asymptomatic carotid artery stenosis is a benign lesion. Thompson and associates [20] and Cooperman and colleagues [21] have presented convincing data that late neurologic complications occur with significant frequency in patients with asymptomatic carotid artery stenoses unless a CEA is performed. Hertzer and colleagues [22] reviewed 3-year results in patients with advanced asymptomatic carotid artery stenoses and found that CEA reduced late neurologic events. Eventfree survival trends indicated that operations reduced the number of late strokes in patients with greater than 70% lesions and in patients with bilateral lesions greater than 50%. Moneta and coworkers [23] confirmed the value of CEA in asymptomatic patients with high-grade stenoses. In similarly matched asymptomatic patients followed up for 2 years, CEA resulted in a lower stroke rate (4% versus 19%) and fewer TIAs (5% versus 28%). Two recent randomized, prospective trials have demonstrated that CEA in asymptomatic patients with high-grade carotid artery stenosis will reduce the risk of subsequent TIAs and strokes [24, 25]. There was, however, no in-depth evaluation of the presence of coronary artery disease in these patients. In view of these data, should CEA be recommended for all asymptomatic patients with unilateral lesions? Although there is evidence to suggest that patients with at least 60% carotid stenosis will have a higher incidence of a neurologic event within 5 years [24, 25], the outcome of prophylactic CEA in asymptomatic patients who require CABG operation is still not clear. It appears that patients with carotid artery disease are at a higher risk for the development of neurologic events after CABG. Patients with synchronous carotid and coronary arteriosclerosis tend to be older and have more extensive peripheral vascular disease, as well as an increased incidence of left main coronary artery disease and reduced ventricular function. In the series by Bull and associates [2], the presence of a carotid artery stenosis did not correlate with a postoperative CVA, but was associated with the presence of ventricular thrombus and atherosclerotic debris in the ascending aorta. Similarly, Ricotta and coworkers [26] could not correlate anatomic stroke distribution with the site of a carotid artery stenosis in more than 50% of their CABG patients. Those patients with carotid artery lesions had a higher incidence of peripheral vascular disease and arteriosclerosis of the ascending aorta. D Agostino and coworkers [17] also report that independent predictors of postoperative neurologic events include prior stroke or TIA, peripheral vascular disease, postoperative atrial fibrillation, carotid artery stenosis equal to or greater than 50%, and significant aortic arteriosclerosis. This lends further credence

3 970 REVIEW LAZAR AND MENZOIAN Ann Thorac Surg CABG AND CEREBROVASCULAR DISEASE 1998;66: to the argument that an asymptomatic carotid artery stenosis is more likely to be found in patients who are vasculopaths and may not by itself be the cause of a perioperative neurologic event. The emerging evidence that CEA may afford long-term protection against neurologic events in asymptomatic patients raises new issues about the role of combined CEA and CABG procedures in patients with asymptomatic carotid artery stenosis [24, 25]. The increased incidence of perioperative neurologic events in patients with high-grade lesions may be the result of arteriosclerotic debris in the ascending aorta and ventricular thrombi in patients with recent infarcts. Whether combined CEA and CABG will offer the asymptomatic patient with a carotid artery stenosis protection from a neurologic event during CABG will depend on the (1) experience of the operating team, (2) age of the patient, (3) extent and urgency of the coronary artery disease, and (4) extent and severity of the carotid artery occlusions. This will be discussed in further detail in the section on the role of combined CEA and CABG. Cerebral Perfusion During Cardiopulmonary Bypass in Patients With Carotid Artery Stenosis There are two mechanisms by which neurologic injury can occur in patients with carotid artery stenosis during cardiopulmonary bypass. Changes in hemodynamics may cause embolization of thrombotic debris from ulcerated carotid artery plaques, as well as from those in the ascending aorta. A stenotic carotid artery lesion might result in cerebral hypoperfusion resulting in a watershed infarct. In an attempt to determine whether alterations in perfusion pressure and cerebral blood flow might increase neurologic events during cardiopulmonary bypass, Johnsson and coworkers [27] studied patients with bilateral carotid artery stenosis undergoing CABG. Seven asymptomatic patients with at least 50% bilateral carotid artery lesions documented by Doppler studies and 17 patients without carotid artery disease had cerebral blood flow measured using xenon 133 washout techniques. Perfusion pressure was kept at a minimum of 50 mm Hg, and patients were cooled to 30 C. There was no difference in cerebral blood flow between the two groups. No patient in the carotid artery stenosis group had any evidence of a postoperative neurologic deficit. Similar results were reported by Ivey and coworkers [10], who found that patients with carotid artery stenoses had no increased incidence of perioperative neurologic events provided that perfusion pressure was kept equal to or greater than 70 mm Hg. Powers and associates [28] have shown that the degree of carotid artery stenosis has no bearing on the hemodynamic status of the distal cerebral hemisphere as measured by positron emission tomography. In summary, it appears that cerebral perfusion during cardiopulmonary bypass in patients with carotid artery stenoses can be safely maintained as long as pressures are at least 50 mm Hg. Neurologic events that occur during cardiopulmonary bypass appear to be more related to arteriosclerotic aortic disease than to low flow across a carotid artery stenosis. The Role of Combined Carotid Endarterectomy and Coronary Artery Bypass Grafting Procedures In an early series of isolated CEAs performed in the presence of severe coronary artery disease, the hospital mortality was 18% with cardiac complications accounting for 78% of all morbidity and mortality [29]. This was in contrast to a 1.5% mortality for patients having CEA without coronary artery disease. In a series of staged CEA for patients with coronary artery disease, Bernhard and coworkers [30] reported an operative mortality of 33%. These poor results prompted these investigators to perform a combined CEA and CABG in 16 patients with symptomatic carotid and coronary artery disease. This was accomplished without any operative mortality, infarction, or stroke. These authors recommended that simultaneous CEA and CABG was the most effective means of avoiding myocardial complications and reducing neurologic deficits. Since then several groups have reported their results with combined CEA and CABG, with operative mortalities ranging from 0% to 5%, perioperative neurologic events ranging from 0% to 3%, and myocardial infarcts averaging 3% [4, 12, 31 36]. At the same time, the incidence of permanent neurologic deficits in patients undergoing CABG without CEA, but with carotid artery disease, has averaged 5.5% [10, 12, 26, 29, 32, 37 39]. One of the problems in comparing series of patients with carotid artery disease undergoing CABG without CEA is that the extent of the carotid and coronary artery disease may not be accurately documented. Two studies have been reported in which the authors found that the operative morbidity and mortality for combined CEA and CABG was higher than for each procedure alone [3, 40]. Hertzer and coworkers [3] reported an operative mortality of 5.7% with a 4.5% incidence of permanent neurologic deficits. In the series by Lord and associates [40], there was a 4.8% infarct rate with a 7.1% incidence of perioperative neurologic events. In both these series there was an increased incidence of older patients, a higher percentage of left main coronary artery disease, and significantly decreased ejection fractions. Hence, patient selection is important in ultimately determining the efficacy of combined CEA and CABG procedures. There have been several large series that have attempted to better define the role of CEA and CABG in clinical practice. Jones and colleagues [32] studied 132 patients with combined CEA and CABG procedures and compared them with 167 patients with elective CABG operation. The mean age of the patients and incidence of hypertension was significantly higher in the combined CEA and CABG group. The most common indication for a combined CEA and CABG was an asymptomatic bruit (67%). The incidence of patients having TIAs was 26%, and those with a prior CVA was 7%. There was no difference in mortality (3% versus 1.6%) or perioperative CVA (0.6% versus 0.6%) between the combined CEA and

4 Ann Thorac Surg REVIEW LAZAR AND MENZOIAN 1998;66: CABG AND CEREBROVASCULAR DISEASE 971 CABG and CABG-only groups. Patients with asymptomatic bruits in both groups had the lowest incidence of perioperative neurologic events. Although the study implies that combined CEA and CABG can be performed with low morbidity and mortality, it fails to determine whether patients with asymptomatic bruits are protected from postoperative CVAs by having a combined procedure. In fact, the data imply that the incidence of CVAs is not altered in this patient population. Another large series of combined CEA and CABG procedures was reported by Rizzo and coworkers [41] from the Brigham and Women s Hospital in Boston. From 1978 to 1991, 167 patients underwent a combined CEA and CABG procedure. Asymptomatic bruits were present in 32%, TIAs in 48%, and 20% had a prior CVA. Left main coronary artery disease was found in 38%, and 28% of patients had an ejection fraction less than 0.50, confirming other series that showed that patients with carotid artery stenosis have a higher incidence of left main coronary artery disease and decreased ejection fractions [4 8]. In addition, 59% of these patients had bilateral carotid artery stenoses and 16% had a contralateral occlusion. The operative mortality in this series was 5.5%; all deaths were cardiac related. A permanent CVA occurred in 5.5%, of which 3.9% were ipsilateral to the carotid artery lesion. In historical controls at the Brigham and Women s Hospital, the incidence of a CVA after isolated CABG was 1% and 1.5% after an isolated CEA. As in earlier series, a perioperative CVA did not occur in patients who had asymptomatic carotid artery stenoses. Patients with combined CEA and CABG had decreased long-term survival compared with patients with isolated coronary artery disease, especially if their ejection fraction was reduced. The 5-year survival for patients with an ejection fraction greater than 0.50 was 70% compared with 45% if the ejection fraction was less than 0.50 (p 0.03). The freedom from development of a late CVA at 8 years was 90% for asymptomatic patients and those with TIAs, but fell to 71% for patients having had a prior CVA. In this series, patients with asymptomatic lesions had a 0% incidence of a perioperative CVA. This increased to 9% for patients with symptomatic lesions, 15% for bilateral lesions or a contralateral occlusion, and 19% for patients having had a prior CVA. These results are consistent with the data of Hertzer and colleagues [3] and Brenner and associates [12], who showed a higher incidence of CVAs in patients with bilateral stenoses either in combined or isolated CABG procedures. The series by Rizzo and coworkers [41] reinforces previous studies, which show that combined procedures for asymptomatic lesions can be performed with a low incidence of perioperative neurologic events. It does not, however, prove that the incidence of CVAs are reduced in these patients in the perioperative period. Hertzer and colleagues [39] at the Cleveland Clinic performed combined procedures in 275 patients. In this series, 29% of patients had a previous neurologic event, and 71% had at least 50% stenosis by angiogram and were symptomatic. As in other series, these patients tended to be older and had a higher incidence of left main coronary artery disease and reduced left ventricular function. Operative mortality was higher in the patients with a combined procedure compared with a cohort of patients undergoing isolated CABG (4.7% versus 2.5%). However, the incidence of neurologic events was decreased in combined patients as opposed to patients who underwent staged procedures for symptomatic lesions (4.7% versus 7.4%). The highest incidence of neurologic symptoms was found in patients with bilateral stenoses. Three recent studies show that combined CEA and CABG operation can be done with acceptable stroke and mortality rates [42 44]. Akins and associates [42] report a perioperative stroke rate of 3% and mortality rate of 3.5% with concomitant CEA and CABG. There was no randomization of the 200 patients, and 58% of the patients had asymptomatic carotid artery stenoses, a group that would be expected to have a low stroke rate with CABG alone [19]. A similar study by Trachiotis and coworkers [43] shows a 4.5% stroke rate and a mortality rate of 3.4% with a combined operation. This was not a randomized trial, and the indications for the combined procedures were not clear in these 88 patients who included patients with symptomatic and asymptomatic carotid artery stenosis. Daily and coworkers [44] also report acceptable mortality and stroke rates with combined CEA and CABG as well as reduced hospital costs using this approach. From these studies, it would appear that combined CEA and CABG procedures can be done with low morbidity and mortality but that this does not significantly reduce the incidence of operative mortality and neurologic events in patients with asymptomatic carotid artery lesions, and, in our opinion, combined CEA and CABG would best be reserved for patients with active TIA symptoms and possibly patients with severe bilateral lesions. However, as noted earlier, there are series that reported that patients with high-grade ( 70%) carotid artery stenoses that are not operated on have an increased stroke rate at 5 years that is 20% to 30% higher than patients who are operated on, irrespective of whether the lesion is symptomatic or asymptomatic at the time of its discovery [22, 44]. Hennerrici and coworkers [13] have shown that in asymptomatic patients with high-grade carotid artery stenoses, the stroke rate is 4% to 5% per year, in patients with TIAs it is 6% per year, and in patients with a history of a prior CVA, it is 4% to 5% per year. Hertzer and Arison [45] have shown that after a successful CEA the stroke rate was reduced to 1.1% to 1.5% in asymptomatic patients, 1% to 2% in patients with TIAs, and 3% to 4% in patients who have already had a completed CVA. The results of recent clinical trials in patients with asymptomatic carotid artery stenoses also strongly suggest that CEA is beneficial in reducing longterm neurologic events in patients with asymptomatic carotid artery disease [24, 25]. There are several studies that may support these conclusions. Barnes and colleagues [37] and Schultz and associates [38] each reported on 90 patients who underwent isolated CABG in the presence of a carotid artery lesion. Although there was only a 1.2% incidence of any neurologic events

5 972 REVIEW LAZAR AND MENZOIAN Ann Thorac Surg CABG AND CEREBROVASCULAR DISEASE 1998;66: during the perioperative period, late events did occur. Follow-up at 41 months revealed that 4.4% of patients had experienced a CVA, of which 3.3% were ipsilateral, and 13% had TIAs. These two groups of authors believe that as not all CVAs are preceded by transient symptoms, combined procedures should be done in these patients. Kaul and coworkers [11] studied 175 patients who had undergone combined CEA and CABG procedures to determine long-term outcomes. The hospital mortality was 3.4%. At 12 years, the freedom from a neurologic event was 86% in the entire group of patients. However, it was only 73% in patients with bilateral carotid artery disease when only a single CEA was performed. In contrast, patients with unilateral disease had a 90% freedom from having a major neurologic event. This study adds further evidence to the premise that late neurologic sequelae do occur in patients with carotid artery lesions who do not undergo a CEA. What conclusions can be drawn from these studies regarding the role of combined CEA and CABG procedures? Patients with an asymptomatic carotid artery stenosis less than 70% do not appear to have any reduction in the incidence of perioperative neurologic events with combined procedures. Patients with a completed CVA and the absence of significant carotid artery stenoses ( 70%) also do not appear to receive early postoperative benefits from combined procedures. Patients with active neurologic symptoms, bilateral lesions with or without a contralateral occlusion, and previous CVAs with at least 70% lesion appear to have a decreased incidence of neurologic events with a combined CEA and CABG procedure versus a staged procedure. The series by Hertzer and coworkers [39] suggests that a combined operation for patients with asymptomatic but significant ( 70%) carotid artery stenoses may afford long-term protection against major neurologic events. In this study, the authors compared their results with staged procedures (CEA followed by CABG) and combined CEA and CABG procedures. They suggest that CEA before CABG can be performed in patients with chronic stable angina in the absence of a recent myocardial infarction. They recommend combined CEA and CABG for patients with severe left main coronary artery disease, patients with diffuse coronary artery disease without satisfactory collaterals, and patients with unstable angina. Whether combined CEA and CABG offers protection from a major neurologic event will depend on many factors. This will include the experience of the operating team and their ability to achieve low morbidity and mortality; the age and existing comorbid medical conditions of the patient; the severity of the coronary artery disease, ejection fraction, and urgency of the CABG operation; the severity of the carotid artery disease; and whether the lesions are bilateral high-grade stenoses or total occlusions. Advocates of the combined procedure believe that there is more efficient use of the operating room facility and surgical personnel resulting in shortterm hospitalization and lower medical costs. Patients with coexisting carotid and coronary artery disease represent a high-risk surgical group and it will be difficult to make clear-cut recommendations in the asymptomatic patient with a significant carotid artery stenosis. Ultimately, carefully controlled prospective randomized studies from several institutions specifically addressing the issue of the asymptomatic, significant carotid artery lesion in the CABG patient will be necessary to determine which patients will benefit from combined CEA and CABG procedures. Surgical Techniques of Carotid Endarterectomy and Coronary Artery Bypass Graft Procedures Once the decision has been made to perform a combined CEA and CABG procedure, does it make a difference whether the CEA is done before or during cardiopulmonary bypass? In two separate series using matched groups, Schwartz and associates [6] and Lord and coworkers [40] could not demonstrate any difference in morbidity or mortality between performing the CEA before or during cardiopulmonary bypass. Matar [46] and Minami and colleagues [34] both demonstrated that performing the CEA during cardiopulmonary bypass does not increase the incidence of bleeding or prolong hospital stay. Recently, Kouchoukos and coworkers [47] have reported the technique of performing the CEA during a period of circulatory arrest, which averaged 30 minutes. The incidence of neurologic events was 0% and the 30-day mortality was 6%. Our preference, like that of most authors, is to perform the CEA before cardiopulmonary bypass. After general anesthesia is induced and the patient is prepared for operation and draped, the CEA team proceeds to expose the carotid artery. Simultaneously, the cardiac team is harvesting the saphenous vein or the radial artery. The CEA is performed using systemic heparinization and a shunt. Once the CEA is completed, the heparin is not reversed, and the neck wound is packed but not closed. The chest is opened, the internal mammary artery is harvested, and the patient is placed on cardiopulmonary bypass and the revascularization is completed. After the heparin is reversed, the neck excision is carefully checked for bleeding and the wound is closed. Conclusions What conclusions can be drawn regarding patients who require a CABG operation and have associated cardiovascular disease? Patients who are asymptomatic and have a carotid artery bruit should have a Doppler duplex study to determine the significance of their carotid artery disease. A lesion that is less than or equal to 70% in an asymptomatic patient will not by itself increase the incidence of a perioperative neurologic event and will not indicate the need for a combined procedure. Furthermore, the Doppler duplex study will serve as a baseline for further comparison in a patient population known to be more susceptible to arteriosclerotic disease. Those CABG patients who have TIAs, bilateral carotid artery lesions at least 50% with or without a contralateral occlusion, or a prior CVA with a high-grade, at least 70% residual lesion are more likely to have an increased incidence of perioperative neurologic events and appear

6 Ann Thorac Surg REVIEW LAZAR AND MENZOIAN 1998;66: CABG AND CEREBROVASCULAR DISEASE 973 to benefit from a combined CEA and CABG procedure. Controversy still exists regarding the role of a combined CEA and CABG operation for the asymptomatic patient with a significant ( 70%) unilateral carotid artery lesion. Although it appears that these patients do not have an early risk for a perioperative neurologic event, studies suggest that there is a significant long-term risk for the development of a CVA. The decision to perform a combined procedure in these patients will depend on many factors, including the age of the patient, the urgency and severity of the coronary artery disease, the level of left ventricular function, and the presence of comorbid medical diseases. 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7 974 REVIEW LAZAR AND MENZOIAN Ann Thorac Surg CABG AND CEREBROVASCULAR DISEASE 1998;66: ease: one stage surgical treatment. J Thorac Cardiovasc Surg 1982;30: Emery RW, Cohn LH, Whittemore AD, et al. Coexistent carotid and coronary artery disease. Arch Surg 1983;118: Barnes RW, Nix ML, Sansonetti D, Turley DG, Goldmen MR. Late outcome of untreated asymptomatic carotid disease following cardiovascular operations. J Vasc Surg 1985;2: Schultz RD, Sterpetti AV, Feldhaus RJ. Early and late results in patients with carotid disease undergoing myocardial revascularization. Ann Thorac Surg 1988;45: Hertzer NR, Loop FD, Beven EG, O Hara PJ, Krajewski LP. Surgical staging for simultaneous coronary and carotid disease: a study including prospective randomization. J Vasc Surg 1989;9: Lord RSA, Graham AR, Shanahan MX, et al. Combined carotid coronary reconstruction: synchronous or sequential? Aust NZ J Surg 1985;55: Rizzo RJ, Whittemore AD, Couper GS, et al. Combined carotid and coronary revascularization: the preferred approach to the severe vasculopath. Ann Thorac Surg 1992;54: Akins CW, Moncure AC, Daggett WM, et al. Safety and efficacy of concomitant carotid and coronary artery operations. Ann Thorac Surg 1995;60: Trachiotis GD, Pfister AJ. Management strategy for simultaneous carotid endarterectomy and coronary revascularization. Ann Thorac Surg 1997;64: Daly PO, Freeman RK, Dembitsky WP, et al. Cost reduction by combined carotid endarterectomy and coronary artery bypass grafting. J Thorac Cardiovasc Surg 1996;111: Hertzer NR, Arison R. Cumulative stroke and survival 10 years after carotid endarterectomy. J Vasc Surg 1985;2: Matar AF. Concomitant coronary and cerebral revascularization under cardiopulmonary bypass. Ann Thorac Surg 1986;41: Kouchoukos NT, Baily JB, Wareing HT, Murphy JF. Hypothermic circulatory arrest for cerebral protection during combined carotid and cardiac surgery in patients with bilateral carotid artery disease. Ann Surg 1994;219: Discussion Groups on the Internet The following three articles will be published in the October 1998 issue of The Annals of Thoracic Surgery, and have been selected for discussion topics on the Internet. These discussion groups can be accessed by going to The Society of Thoracic Surgeons Home Page ( and clicking on Discussion Forums. We encourage everyone to participate, as our goal is to make the discussion as interactive as possible. Biventricular Repair in Neonates With Hypoplastic Left Heart Complex Christo I. Tchervenkov, MD, Stephen A. Tahta, MD, Luc C. Jutras, MD, and Marie J. Béland, MD Central Venous Catheter Use in Low-Risk Coronary Artery Bypass Grafting Robert D. Stewart, MD, Triffin Psyhojos, MD, Stephen J. Lahey, MD, Sidney Levitsky, MD, and Christian T. Campos, MD Evaluation of Treatment Modalities for Thoracic Empyema: A Cost-Effectiveness Analysis Vinod H. Thourani, MD, Kevin M. Brady, MD, Kamal A. Mansour, MD, Joseph I. Miller, Jr, MD, and Robert B. Lee, MD Tom Karl, MD Internet Annals Editor Melbourne, Australia karl@cryptic.rch.unimelb.edu.au 1998 by The Society of Thoracic Surgeons Ann Thorac Surg 1998;66: /98/$19.00 Published by Elsevier Science Inc