Cerebral haemodynamic aspects of severe carotid stenosis: asymptomatic vs symptomatic.

OBJECTIVES: to compare cerebral haemodynamics in patients with asymptomatic and symptomatic severe (> or =70%) internal carotid artery (ICA) stenosis. METHODS: we assessed 195 consecutive patients, 116 with asymptomatic carotid stenosis (ACS) and 79 with symptomatic carotid stenosis (SCS). Using transcranial Doppler we assessed cerebral vasoreactivity (CVR) following acetazolamide test, the middle cerebral artery flow velocity ratio after/before carotid clamping (mv-MCA ratio), and the carotid back pressure (CBP) during crossclamping. RESULTS: no significant differences between the two groups were demonstrated regarding CVR (47 vs 39%), mv-MCA ratio (50 vs 52%), or CBP (36 vs 44 mmHg). However, in patients with contralateral ICA occlusion all three variables were significantly lower as compared to patients with patent contralateral ICA. Also patients who needed a shunt during surgery had significantly lower values of mv-MCA ratio and CBP. Patients who suffered peri-operative neurologic deficits (n=6; 3%) did not differ from patients who had an uneventful course. CONCLUSIONS: clinical state of ICA stenosis is independent of cerebral haemodynamics. Occluded contralateral ICA is more important for predicting cerebral ischaemia caused by carotid clamping. Finally, none of the haemodynamic parameters showed predictive value for peri-operative neurologic morbidity.     

Carotid endarterectomy without a shunt: the control series

Nine hundred forty carotid endarterectomies were performed without the use of a temporary indwelling shunt. Six patients (0.6%) died, all from stroke; 17 other patients (1.8%) had another stroke, and 21 patients (2.2%) had temporary neurologic symptoms. Complete x-ray films detailing the opposite internal carotid artery and carotid artery back pressure were available for 783 operations. Correlation of stroke to back pressure, status of the contralateral internal carotid artery, preoperative neurologic deficit, and carotid clamp time was examined. Statistical analysis demonstrated significantly increased neurologic complications only if the systolic carotid back pressure was less than or equal to 50 mm Hg or the contralateral internal carotid artery was occluded. Analysis to determine if these factors were dependently related showed that when both a contralateral carotid occlusion and a carotid back pressure of less than or equal to 50 mm Hg coexisted (82 patients), the rate of permanent deficit was 11.0% compared with 2.8% when either factor was singly present and 0.9% when neither factor was present. No statistical difference exists between the group with only a single factor and those with neither factor. When a temporary shunt is not used during carotid endarterectomy, the risk of neurologic complication is increased if both a contralateral internal carotid artery occlusion and a carotid back pressure of less than or equal to 50 mm Hg coexist. The use of a shunt in this patient population may be beneficial.     

Carotid endarterectomy in the presence of a contralateral occlusion: a review of 315 cases over a 27-year experience

Recent data from the North American Symptomatic Carotid Endarterectomy Trial revealed a 14.3% perioperative risk of stroke or death with carotid endarterectomy contralateral to a carotid artery occlusion. Since last reporting on this topic in the mid-1980s, the authors have reviewed 180 patients with occlusion of one internal carotid artery (ICA) and who underwent endarterectomy of the stenotic contralateral ICA operated from 1965 to 1984 (group A) compared with 135 operated on from 1985 to 1991. The two groups were similar with respect to age, sex, incidence of coronary artery disease, hypertension, diabetes and history of smoking, but group B had a significantly increased incidence of patients who were neurologically symptom-free before surgery (21.5% versus 7.8%, P < 0.001). The combined perioperative stroke or death rate for patients in group B was significantly lower than for those in group A (0.7% versus 6.7%, P < 0.01). Comparison of the operative techniques showed more frequent placement of intra-arterial shunt (52.6% versus 29.4%, P < 0.001) and increased use of general anesthesia (20.0% versus 9.4%, P < 0.01) in patients of group B. Analysis of the etiology of the complications, however, showed that shunting alone could not account for the improved results. Lower incidences of postoperative thrombosis, embolization and intracerebral hemorrhage were equally important. From these data and a review of the literature, it is concluded that: (1) complications from carotid endarterectomy in patients with ICA stenosis and contralateral occlusion cannot be attributed to a single technical problem; (2) the reported high incidence of perioperative stroke or death with these patients reflects the added risk that any ischemic insult may result in a neurologic event; and (3) improved selection of patients and careful attention to cerebral perfusion and reconstruction of the carotid artery after endarterectomy can reduce the operative risks.     

Determining criteria for shunt placement during carotid endarterectomy. EEG versus back pressure

EEG monitoring and carotid back pressure were performed on 100 patients undergoing elective carotid endarterectomy. Shunts were inserted selectively in those patients who showed change in EEG after a trial period of carotid clamping (15%). No patient in the series awoke with a neurologic deficit. Back pressures were significantly lower in the shunted group and these pressures roughly correlated with EEG changes. Only one patient with a back pressure of greater than 40 mmHg had EEG changes and this patient had a recent mild stroke. EEG changes were most frequent in patients with contralateral carotid occlusions and in asymptomatic significant stenoses. EEG is a more discriminating indicator for shunt insertion than back pressure, although a pressure greater than 40 mmHg is safe in patients without recent stroke.     

Carotid endarterectomy with routine electroencephalography and selective shunting: Influence of contralateral internal carotid artery occlusion and utility in prevention of perioperative strokes

OBJECTIVE: Carotid endarterectomy (CEA) is associated with a risk of cerebral ischemia during carotid clamping, particularly in the face of contralateral internal carotid artery (ICA) occlusion. We examined the results of CEA with continuous electroencephalography in patients without and with contralateral ICA occlusion. DESIGN AND SETTING: We reviewed 564 primary CEAs with routine electroencephalography and general anesthesia performed between April 1, 1989, and March 31, 1999, in a community teaching medical center. Main outcome measures were perioperative stroke, temporary lateralizing neurologic deficit, and death. Shunts were placed primarily for significant electroencephalographic changes after carotid clamping but also selectively for contralateral ICA occlusion, prior stroke, or surgeon choice. CEA was performed for asymptomatic disease in 35% of cases. RESULTS: Significant electroencephalographic changes occurred in 16% versus 39% (P <.001) and shunts were placed in 13% versus 55% (P <.001) of patients with patent (n = 507) versus occluded contralateral ICA (n = 57), respectively. The fraction of CEAs with significant electroencephalographic changes during clamping was stable, but shunt use declined slightly over time as our confidence in electroencephalography increased. Patches were placed more often (86% versus 65%; P =.002), but other operative details were similar when the contralateral ICA was occluded. Five early (30 days) strokes (0.9%) and eight early temporary postoperative neurologic events (1.4%) occurred, all ipsilateral to CEA and all after the patient left the operating room with none in patients with contralateral ICA occlusion. Two perioperative deaths occurred, one in a patient without and one in a patient with contralateral ICA occlusion. Neither of these deaths was related to ipsilateral stroke. No increase in stroke rate with decreased shunt use over time was seen. CONCLUSION: Routine use of electroencephalography was associated with apparent complete elimination of intraoperative strokes and less than 1% risk of perioperative strokes. These observations appear to be true even in the face of contralateral ICA occlusion. Electroencephalography is a sensitive detector of cerebral ischemia and a valuable tool for determination of need for shunting during CEA. Surgeons should consider routine use of electroencephalography and selective shunting for significant electroencephalographic changes with clamping.     

Single-center prospective, randomized analysis of conventional and eversion carotid endarterectomy

AIM: Several studies, comparing early and long-term results of the conventional carotid endarterectomy (CEA) and eversion carotid endarterectomy (EEA), were conducted for past 10 years. Nevertheless, it still remaining difficult to choose optimal endarterectomy technique. Choice yet mainly depends of experience of attending surgeon. The aim of this study was the comparison early and long-term results of the EEA and CEA. METHODS: Randomly, 103 patients were operated on in the eversion, and 98 patients in the conventional technique; 97 (48.3%) patients were asymptomatic and 104 (51.7%) had symptomatic lesions. All patients underwent preoperative cervical duplex scaning and neurological examination. The surgical procedure was carried out under general anesthesia. In cases with retrograde blood pressure less than 20 mmHg shunt was used; 78.6% of all CEA were finished up with 'patch' angioplasty and 21.4% by primary suture. The primary outcomes were perioperative and late mortality, perioperative and late central neurological complications, a long-term survival rate and late restenosis incidence. RESULTS: The mean follow-up was 38 months. Mortality and long-term survival rate were similar in compared groups. The perioperative central neurological complications incidence were comparable in study groups (3.9% vs 12.1% ,odds ratio 3.45, 95% confidence interval 1.1-11.1; P=0.029). The late restenosis incidence was significantly lower in eversion group (0.0% vs 6.1%). CONCLUSION: EEA has an advantage over the conventional procedure. The authors recommend CEA in cases when retrograde pressure indicated the use of the intraluminal shunting.     

Asymptomatic carotid lesions after endarterectomy of contralateral carotid artery. Five-year follow-up study and prognosis

Of 185 patients who consecutively underwent carotid endarterectomy five years ago, 135 had a patent asymptomatic contralateral internal carotid artery (ICA). During follow-up (median, 59 months), 36 patients developed new neurologic symptoms (18 strokes and 18 transient ischemic attacks). Thirteen patients developed symptoms referable to the territory of the previously asymptomatic ICA (five strokes and eight transient ischemic attacks). Using life-table analysis, the annual stroke rate was estimated to be 1% and 2.2% considering the previously asymptomatic and symptomatic ICA, respectively. Separating patients according to the degree of stenosis on the preoperative angiogram and according to the presence of ulceration revealed a significantly higher incidence of neurologic events and strokes in patients with stenoses exceeding 50% and/or patients with obvious ulcerations. Although the risk of stroke without warning was increased in these subgroups, we did not consider the risk high enough to warrant prophylactic endarterectomy. An exception enough to warrant prophylactic endarterectomy. An exception may be the patient with a more than 90% stenosis.     

Stenosis following carotid endarterectomy. Its implication in management of asymptomatic carotid stenosis

Carotid endarterectomy is established in the treatment of atherosclerosis of the carotid bifurcation, but the incidence of restenosis and the role of endarterectomy in the management of asymptomatic carotid stenosis are variable. During a four-year period, we performed 80 endarterectomies of the internal carotid artery in 73 patients. Patients were prospectively studied by means of Doppler ultrasonography in combination with real-time spectral analysis to determine the incidence of restenosis postoperatively. A concomitant study of 116 patients with 79 asymptomatic carotid stenoses was undertaken. We found a 12.5% incidence of stenosis following carotid endarterectomy and a 3% risk of transient neurologic deficit in the patients with asymptomatic carotid stenoses.     

Does contralateral internal carotid artery occlusion increase the risk of carotid endarterectomy?

The results of every carotid endarterectomy performed contralateral to an internal carotid artery occlusion (n = 36) (group I) were compared with those performed contralateral to a patent internal carotid artery (n = 169) (group II) over the last 10 years. The patients in each group were evenly matched with respect to male gender (66% vs 69%); mean age (66.7 vs 65.9 years); and incidence of hypertension (55.6% vs 53.2%), diabetes (16.7% vs 20.1%), and hyperlipidemia (8.3% vs 11.8%). Patients in group I had a higher incidence of previous myocardial infarction (25% vs 11.8%, p less than 0.05) and exertional angina (55.6% vs 29.6%, p less than 0.01). Indications for carotid endarterectomy were equivalent, including stroke (19.4% vs 21.9%), transient ischemic attacks (36.1% vs 35.5%), amaurosis fugax (16.7% vs 11.8%), nonhemispheric symptoms (5.6% vs 8.3%), and asymptomatic stenoses (22.2% vs 22.5%), respectively. Perioperative strokes occurred in one (2.8%) patient in group I and seven (4.1%) patients in group II (NS). Among the patients in group II the incidence of perioperative stroke did not correlate directly with the degree of contralateral ICA stenosis: greater than 90% (4%); 70% to 90% (6.7%); 50% to 70% (8.7%); and less than 50% (2.8%). The operative mortality rate was 0% among patients in group I and 1.2% among patients in group II (NS). Cardiac complications occurred in two (5.6%) patients in group I and nine (5.3%) patients in group II (NS).(ABSTRACT TRUNCATED AT 250 WORDS)     

Timing of carotid endarterectomy after acute stroke

An arbitrary delay of at least 6 weeks before performing carotid endarterectomy after acute stroke has been recommended based on anecdotal reports. This prolonged interval may increase the danger of recurrent neurologic deficit before surgery. From September 1978 to September 1988, carotid endarterectomy was performed on 140 patients at variable intervals after stroke. Eleven patients had temporary stroke, which left 129 patients with neurologic symptoms that persisted for 3 weeks or had a cortical infarct on CT scanning. A prospective therapeutic protocol was applied to 82 patients admitted with acute stroke. They were observed until neurologic recovery reached a plateau, based on clinical observation by a neurologist, before performing angiography and carotid endarterectomy (group I). Forty-seven patients were not seen until after recovery from stroke was established (group II). At initial presentation, the severity of neurologic deficit was classified as mild, moderate, or severe in 31%, 58%, and 11%, respectively. Recovery before operation was registered as complete in 11%, mild residual in 66%, moderate residual in 21%, and severe residual in 2%. Group I patients (n = 82, 64%) were operated on within 6 weeks of stroke and group II (n = 47, 36%) were operated on at varying times after 6 weeks. No significant difference was found in the incidence of cerebrovascular events (1.2% vs 4.2%) and deaths (1.3% vs 2.1%) between groups I and II with respect to the timing of carotid endarterectomy, and no significant difference was found between patients operated on at 2, 4, 6, or more than 6 weeks after stroke.(ABSTRACT TRUNCATED AT 250 WORDS)     

Carotid endarterectomy after reversible ischemic neurologic deficit or stroke: is it of value?

The benefit of carotid endarterectomy (CE) in preventing recurrent stroke and improving survival in the patient who has sustained a reversible ischemic neurologic deficit (RIND) or stroke is still controversial. To determine the long-term benefits and value of CE in these patients, a 10-year review of 253 patients who suffered a RIND or stroke was conducted. All patients had CT brain scans, as well as arch, extracranial, and intracranial arteriography; any patients without demonstrated carotid bifurcation disease were excluded from the study. On the basis of clinical symptoms and CT scan findings, 66 patients were categorized as having sustained a RIND and 187 a stroke. One hundred fifty-one patients who suffered a RIND or stroke had CE, whereas 102 patients with RIND or stroke did not have CE and served as a control group. All endarterectomies were performed with a temporary indwelling shunt. Postoperative complications included two deaths (1%), six strokes (4%), and 10 transient neurologic deficits (7%). In follow-up extending to 10 years the cumulative incidence of recurrent stroke was only 7% (11 patients) in the operated group, whereas 18% of patients in the nonoperated control group (18) sustained a recurrent stroke (p less than 0.05). As anticipated, the leading cause of death during follow-up was cardiac related; although CE did not significantly improve long-term survival, there was more than a twofold decrease in the incidence of recurrent stroke as a cause of death in the group having CE.(ABSTRACT TRUNCATED AT 250 WORDS)     

Risk factors in a community experience with carotid endarterectomy

Experience with 1035 carotid endarterectomies in a single community over a 2-year period was analyzed. Twenty-two surgeons working in six hospitals were involved. All surgeons had full-time or part-time appointments at the University of Rochester, 18 had special interest in vascular surgery, and eight had obtained a certificate of qualification in vascular surgery. Mortality rate was 1.4% (14 deaths), with additional permanent, nonfatal, neurologic morbidity of 3.4%. Mortality and morbidity were independent of surgeon, caseload, or hospital. Age and prior history of myocardial infarction influenced the incidence of postoperative myocardial infarction but not the incidence of death or neurologic morbidity. Factors that increased the risk of postoperative death or neurologic complication included hypertension; contralateral carotid disease as manifested by stroke, endarterectomy, or occlusion; whether the patient was a woman; and symptoms of crescendo ischemia. Lack of preoperative neurologic symptoms was correlated with decreased risk of myocardial infarction and neurologic complications. Overall mortality and neurologic morbidity associated with operation for "asymptomatic stenosis" was 3.1% (seven of 222 cases). However, the incidence of contralateral carotid disease was high in the patients in the asymptomatic group (60%), and all complications in this group occurred in patients with prior contralateral carotid endarterectomy or occlusion (p less than 0.05).     

Intraoperative monitoring of cerebral function and carotid hemodynamics during carotid endarterectomy

The authors investigated the hemodynamics and monitored the cerebral function to perform the carotid endarterectomy (CEA) safely. The hemodynamics were investigated by measurements of carotid arterial blood flow by an electromagnetic flow meter before and after CEA. And a doppler flow meter applied directly to the carotid arteries to analyze the flow parameters such as peak frequencies (PF), mean frequencies (MF), mode frequencies (Mo F) and % window. We used routinely our specially designed shunt system during surgery, by which stump pressure of the ICA could be measured easily. The cerebral function was evaluated by the amplitude of N20-P25 component of somatosensory evoked potential (SEP). Flow parameters of doppler sounds demonstrated significant changes such as inversion of MF and Mo F, decrease in % window at the poststenotic ICA in the severe stenosis group. By these doppler sounds the extension of stenotic lesion could be detected clearly. The ICA flow showed evidently low values in patients with more than 80% stenosis, which was improved by CEA. With our specially designed T-tube shunt system, stump pressure, side pressure and direct pressure of the ICA could be monitored easily. The mean stump pressure was 52 mmHg and systemic arterial blood pressure was 99 mmHg on the average. SEP revealed evident changes during temporary occlusion in 10 out of 41 patients, which improved following the reflow with the shunt system. Mean stump pressure in the 11 patients was 33 mmHg, and that in the remaining patients were 59 mmHg on the average.(ABSTRACT TRUNCATED AT 250 WORDS)     

External carotid artery shunting during carotid endarterectomy: an alternative for cerebral protection?

OBJECTIVES: to assess the application of external carotid artery (ECA) shunting in cerebral protection during carotid endarterectomy (CEA). DESIGN: prospective study. MATERIALS AND METHODS: the study comprised 137 consecutive patients who underwent CEA under locoregional anaesthesia. Transcranial Doppler was used to monitor the mean velocity of the middle cerebral artery (mv-MCA): (1) before carotid clamping; (2) after clamping both the common and external carotid arteries; (3) after clamping the internal carotid artery alone ("ECA test"). The decision to shunt was based on the occurrence of neurological deficit during carotid clamping. If the ECA test revealed mv-MCA approaching the pre-clamping values ECA shunting was used, whereas the remaining patients in need of a shunt had a standard internal carotid artery (ICA) shunt. RESULTS: shunting was necessary in 12/137 cases (9%). The ECA test indicated that in four cases - 3% of the whole series or 33% of the shunted cases. In these four patients ECA shunting reversed the neurological deficit, and CEA was successfully performed without any complications. CONCLUSIONS: ECA shunting could be considered as an alternative to standard ICA shunting. Suitable cases can be identified on the basis of the ECA test.     

Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation

OBJECTIVE: Hemodynamically relevant internal carotid artery (ICA) stenosis is a major cause of ischemic stroke. Despite its long-term benefit, carotid endarterectomy may also be associated with severe neurologic deficits. Intraoperative and early recognition of ischemia in the region of the ICA may reduce this risk. To date, direct imaging and quantitative analysis of microvascular structures and function in the human ICA region have not been possible. We purposed to visualize and quantify ischemia/reperfusion-induced microcirculatory changes in the terminal vascular bed of the ICA in patients undergoing unilateral ICA endarterectomy. METHODS: Sequential analysis of the ipsilateral and contralateral conjunctival microcirculation was performed with orthogonal polarized spectral imaging in 33 patients undergoing unilateral ICA endarterectomy because of moderate or severe ICA stenosis (North American Symptomatic Carotid Endarterectomy Trial score, 75% +/- 13%), before clamping the ICA (baseline), during clamping of the external carotid artery and ICA, during reperfusion of the ICA (intraluminal shunt), during the second clamping of the ICA (shunt removal), after declamping (reperfusion) of the external carotid artery and ICA, and 15 to 20 minutes after the second ICA reperfusion. RESULTS: During ICA clamping for shunt placement, ipsilateral and contralateral conjunctival capillary perfusion was significantly decreased, but it was completely restored after reperfusion with carotid shunting. Reclamping of the ICA for shunt removal caused microvascular dysfunction, which was significantly less pronounced than that observed during the first clamping. The individual degree of ICA stenosis was inversely correlated with the ipsilateral and contralateral decrease in conjunctival functional capillary density during the first ICA clamping. CONCLUSIONS: These results suggest adaptive mechanisms of capillary perfusion with increasing stenosis and development of collateral compensatory circulation in the vascular region of the human ICA. Conjunctival orthogonal polarized spectral imaging during unilateral ICA reconstruction enables continuous noninvasive analysis of bilateral conjunctival microcirculation in the terminal region of the ICA and enables monitoring for efficient carotid shunt perfusion during and after endarterectomy.     

Evaluation of changes of systemic blood pressure and shunt incidence in CEA.

BACKGROUND: Induced hypertension is widely recommended as a protective measure in carotid endarterectomy (CEA) to prevent shunt insertion. In this study changes of systemic blood pressure were evaluated in relation to the shunt rate when CEA was performed under local anaesthesia. MATERIALS AND METHODS: In 930 CEAs performed for a high-grade (>70%) ICA stenosis under local anaesthesia the mean systemic blood pressure was measured preoperatively (RR1) and directly before carotid cross-clamping (RR2). A ratio was calculated from these values (RRR=RR2/RR1). A shunt was only inserted for clinical signs of cerebral ischemia. If that became necessary later after cross-clamping had been tolerated primarily, the blood pressure during this period was also recorded (RR3). Also the presence of a contralateral ICA occlusion and baseline blood pressure levels were considered as factors with potential impact on shunt necessity. RESULTS: Among the 638 male (69%) and 292 female (31%) patients with a median age of 70 years (ranging from 52 to 91 years) 82 (9%) had a contralateral ICA occlusion. A shunt was used in 177 operations (19%) and significantly more frequent in patients with a contralateral ICA occlusion (39/82=48% vs. 138/848=16%, p<0,001). RRR was significantly reduced in patients who needed a shunt (0.95 (0.41-1.53) vs. 1.0 (0.54-1.9), p=0.002) which was only true for patients with a patent contralateral ICA. The shunt rate did not differ when contrasting RRR thresholds (<0.7 vs. >1.3) or preoperative blood pressure levels (<100 mmHg vs. >120 mmHg) were compared. RRR did not differ between directly or delayed shunted patients. RR3 did not differ significantly from RR2. A regression analysis identified the presence of a contralateral ICA occlusion as the only independent parameter influencing shunt insertion. CONCLUSIONS: Changes in systemic blood pressure during CEA under local anaesthesia seem to influence shunting rather marginally. The value of induced hypertension to prevent cerebral ischemia should be newly discussed.     

Risk of prophylactic contralateral carotid endarterectomy

Fifty-eight patients underwent a prophylactic contralateral carotid endarterectomy following an initial endarterectomy for symptomatic (38 patients) or asymptomatic (20 patients) carotid stenosis. No deaths occurred after either operation. Two (3.4%) minor neurologic deficits occurred after the initial operation and two (3.4%) major and two (3.4%) minor deficits occurred after the prophylactic contralateral carotid endarterectomy. Sixteen (28%) of the initial endarterectomies were associated with perioperative hyper- or hypotensive episodes compared to 35 (60%) of the prophylactic contralateral carotid endarterectomies (p<0.001). We did not document an increased risk of surgery in patients undergoing prophylactic contralateral carotid endarterectomy soon after the initial operation. All four neurologic events following a prophylactic contralateral carotid endarterectomy occurred when the operation was performed more than five weeks after the initial endarterectomy. The incidence of perioperative hyper- or hypotension was similar in patients undergoing prophylactic contralateral carotid endarterectomy less than or greater than five weeks after the first operation. Our results suggest that a prophylactic contralateral carotid endarterectomy may be associated with a higher incidence of neurologic complications and hyper- and hypotensive episodes than the initial carotid endarterectomy. Waiting more than five weeks to repair a contralateral asymptomatic carotid stenosis may not enhance the safety of the operation.Presented at the Annual Meeting of the Eastern Vascular Society, Pittsburgh, Pennsylvania, May 5, 1991     

Safety and efficacy of one stage off-pump coronary artery operation and carotid endarterectomy

BACKGROUND: Patients with concomitant occlusive disease of coronary and carotid arteries remain at high risk of perioperative stroke and myocardial infarction. Combined coronary artery bypass grafting on cardiopulmonary bypass and carotid endarterectomy has been shown to give good results for this category of patients. In the present study, we analyzed our results of off-pump coronary artery bypass grafting and carotid endarterectomy as a one-stage procedure. METHODS: Between January 1997 and December 2000, 82 patients underwent combined off-pump coronary artery bypass grafting and carotid endarterectomy. All patients were evaluated by preoperative carotid duplex scanning and carotid angiography. All patients had more than or equal to 70% carotid artery stenosis. There were 35 asymptomatic patients (42.7%) and 47 symptomatic patients (57.3%). Carotid endarterectomy was performed before coronary artery bypass grafting in all the patients. RESULTS: There were 66 males (80.5%) and 16 females (19.5%) with a mean age of 63+/-8 years. The average number of grafts was 3.4+/-0.8. There was no hospital mortality. One patient had perioperative myocardial infarction. None of the patients had stroke. One patient had transient neurologic deficit and 1 patient had temporary 12th nerve dysfunction; both recovered completely. There was no incidence of neck wound infection, although 1 patient developed neck hematoma that required reexploration. At a mean follow-up of 2.2+/-0.7 years, 1 patient required contralateral carotid endarterectomy and 1 patient died because of cardiac failure. CONCLUSIONS: Combined off-pump coronary artery bypass grafting and carotid endarterectomy is a safe and effective procedure in patients with significant concomitant carotid and coronary artery disease.     

Neurologic deficit after carotid endarterectomy: pathogenesis and management

During a 7-year period, 818 patients underwent carotid endarterectomy (CE) and were evaluated for postoperative neurologic deficits. Three hundred and eighteen had CE performed with a shunt; transient deficits occurred in 2.9% (nine patients) and permanent deficits occurred in 1.6% (five patients). CE was performed without a shunt in 274 patients; transient deficits occurred in 2.9% (eight patients), while permanent deficits occurred in 2.2% (six patients). CE was monitored by surveillance in 226 patients; transient deficits were found in 2.2% (five patients), while permanent deficits occurred in 1.6% (four patients). There was no significant difference in the incidence of postoperative neurologic deficits between the groups (P greater than 0.25). The concept of inadequate collateral cerebral flow during endarterectomy could not, therefore, be indicted as the cause of the postoperative neurologic complications. Technical errors that caused carotid thrombosis or cerebral emboli, and not inadequate collateral cerebral flow, accounted for most of the neurologic deficits after CE. Deficits occurred most frequently in neurologically unstable patients, those who were first seen with stroke in evolution or with postreversible ischemic neurologic deficit and poststroke symptoms. Twenty-two patients awoke from CE with minor transient deficits, and neurologic function rapidly returned. Fifteen patients with profound postoperative deficits had reoperations immediately; intracranial emboli were identified in three patients, while a thrombosed CE site was demonstrated in seven. Three late (greater than 6 hours) postoperative deficits were due to thrombosis of the CE site. Patients with minimal postoperative deficits will improve without intervention, but reoperation is mandatory if a major deficit occurs in the immediate postoperative period. A protocol for the management of the post-CE neurologic deficit is presented.     

Carotid endarterectomy: a study of cerebral oxygen saturation vs stump pressure

BACKGROUND AND AIMS: Carotid endarterectomy (CEA) is an established surgical procedure for treatment of internal carotid artery (ICA) stenosis. To determine whether or not a carotid shunt is necessary to place, some surgeons measure the stump pressure. We conducted the current study in order to identify whether or not cerebral oxygen saturation (rS02%) can serve as another quantitative measurement to determine the need of carotid shunt during CEA. MATERIALS AND METHODS: Ten patients who underwent CEA under general anesthesia were studied. The stump pressure was measured during ICA clamping and rSO2% was measured during three phases: A) prior to ICA clamping, B) during ICA clamping and C) after ICA declamping. The data were subjected to one-way ANOVA and correlation coefficient analysis. The mean age was 62+/-7 yr and the mean body weight was 66+/-7kg. RESULTS: The stump pressure and rSO2% mean values were 45+/-9 mmHg and 57+/-7% respectively during ICA clamping. Correlation coefficient revealed significant positive relationship, r = 0.724(P = 0.009). CONCLUSIONS: rSO2% may serve as another quantitative measurement to determine the need for carotid shunt during CEA surgery. Due to the small number of cases in the current study, the critical rSO2% which warrants carotid shunt placement could not be identified. Therefore, large number of patients are required to define the critical rSO2% during CEA surgery.