Carotid endarterectomy without a shunt for symptomatic lesions associated with contralateral severe stenosis or occlusion

PURPOSE: The purpose of this study was to assess the adequacy of thiopental protection against ischemic cerebral damage in patients undergoing carotid endarterectomy for symptomatic stenosis greater than 70% in association with contralateral stenosis greater than 70% or contralateral occlusion. METHODS: All patients (n=259) with severe bilateral carotid disease who underwent carotid endarterectomy for symptomatic stenosis greater than 70% were extracted from the database of an ongoing prospective carotid surgery study. Large-dose thiopental sodium without shunting was used for cerebral protection during endarterectomy. Asymmetric electroencephalogram changes during the operation, carotid occlusion time, stroke onset, and neuropathologic outcomes were analyzed. RESULTS: Three contralateral strokes occurred in the series, producing a cerebral morbidity/mortality rate of 1.2% (major 0.4%, minor 0.8%). Transient morbidity was 1.9% made of two reversible ischemic neurologic deficits and three transient ischemic attacks. New asymmetric electroencephalography changes were seen in 49 (19% patients, one of whom had transient deficit. Average occlusion time was 35 minutes. All strokes occurred within 24 hours of the procedure. Patients with previous stroke and and systemic hypertension seemed at greatest risk, and the contralateral hemisphere was the area at greatest risk. All transient deficits were ipsilateral and related to technical complications rather failed protection. CONCLUSIONS: Thiopental cerebral protection eliminates strokes caused by complications of shunting, prevents ischemic stroke during carotid occlusion for periods up to 67 minutes (average 35 minutes), allows meticulous management of the operative site, may modify or minimize clinical neurologic deficit, and in our experience has rendered intraluminal shunting obsolete.     

Incidence, timing, and causes of cerebral ischemia during carotid endarterectomy with regional anesthesia

PURPOSE: Controversy exists regarding the best technique to identify cerebral ischemia during carotid endarterectomy (CEA). Regional anesthesia allows continuous evaluation of neurologic function and therefore can help determine the incidence, timing, and causes of cerebral ischemia. METHODS: The timing and clinical manifestations of any neurologic event during CEA and as long as 30 days afterward was determined by review of operative reports, hospital charts, and outpatient records of consecutive patients who underwent CEA under regional anesthesia over a 68-month period. RESULTS: Two hundred patients underwent CEA; indications were asymptomatic stenosis > 60% in 25%, transient ischemic attack with stenosis > 50% in 52%, and prior stroke with stenosis > 50% in 23%. Eight patients (4%) were converted to general anesthesia for non-ischemic reasons. Of the remaining 192 patients, 183 (95.5%) underwent the procedure with regional anesthesia and no shunt, 2% had cerebral ischemia and underwent shunt placement, and 2.5% had cerebral ischemia, were converted to general anesthesia, and underwent shunt placement. Cerebral ischemia developed in nine patients after carotid cross-clamping, manifested by loss of consciousness in four, confusion in two, dysarthria and confusion in one, and decreased contralateral motor strength in two. Immediate cerebral ischemia developed in four of the nine patients within 1 minute of cross-damping; all four underwent shunt placement. In five of the nine patients, cerebral ischemia occurred between 20 and 30 minutes after cross-clamping; all occurred during relative intraoperative hypotension (average reduction of 35 mm Hg in the systolic pressure). All awake patients in whom ischemic symptoms developed immediately regained and maintained normal neurologic function with shunt placement. Five of 26 patients (19%) with contralateral occlusion required a shunt; none had postoperative ischemia. The mean carotid cross-clamp time was 27 minutes. Postoperative (30 day) complications included a 0.5% stroke rate, a 0.5% rate of postoperative transient ischemic attack, a 0.5% rate of worsening of preexisting acute stroke, and a 0.5% rate of myocardial infarction (no deaths). Of the nine patients who had intraoperative ischemic changes, none had a postoperative neurologic deficit; the three patients who had postoperative neurologic changes had no intraoperative ischemic symptoms. CONCLUSIONS: CEA with regional anesthesia allows continuous neurologic monitoring and can be performed safely even when contralateral occlusion coexists; intraoperative shunting for ischemia is necessary in 4.5% of all cases and in 19% of patients with contralateral occlusion. Intraoperative ischemia was flow-related in our patients; it occurred early from ipsilateral carotid clamping and late from reduced collateral flow as a result of hypotension. Monitoring should be continued throughout cross-clamping to identify late cerebral ischemia. Postoperative cerebral ischemia is not associated with intraoperative ischemia, if corrected.     

Surgical treatment of common carotid artery occlusion

Eight patients with common carotid artery (CCA) occlusion underwent bypass with saphenous vein to either the carotid bifurcation (five), the internal carotid artery (two), or the external carotid artery (one). Indications included ipsilateral transient ischemic attack (two), recent nondisabling hemispheric stroke (two), and transient nonhemispheric cerebral symptoms (two). Two asymptomatic patients with CCA occlusion and contralateral internal carotid stenosis underwent prophylactic revascularization prior to planned aortic surgery. There were no perioperative strokes, occlusions, or deaths. Late ipsilateral stroke occurred in two patients, and one patient had a single transient ischemic attack after 2 years. The four patients with preoperative transient cerebral ischemia experienced relief of their symptoms. Duplex ultrasound is an accurate screening modality for distal patency. Collateral filling of the internal or external carotid artery can usually be demonstrated after aortic arch or retrograde brachial contrast injection. End-to-end distal anastomosis after endarterectomy eliminates the original occlusive plaque as a potential source of emboli. The subclavian artery is preferred for inflow on the left. The CCA origin is easily accessible for inflow on the right. Bypass of the occluded CCA is safe and may be effective in relieving transient cerebral ischemic symptoms, although long-term ipsilateral neurologic sequelae may still occur.     

Elective carotid artery stenting in the presence of contralateral occlusion

Significant carotid stenosis in the presence of an occluded contralateral artery has a poor prognosis with medical therapy alone. Carotid cross clamping during surgical endarterectomy results in critical flow reductions in patients with inadequate collateral flow, and represents a significant risk for procedural strokes. Carotid stenting is being evaluated as an alternative to endarterectomy. We describe the immediate and late outcome of a series of 26 patients treated with carotid stenting in the presence of contralateral carotid occlusion. The mean age of the patients in this group was 65 +/- 9 years, 23 (89%) were men and 10 (39%) were symptomatic from the vessel treated. The procedural success of carotid stenting in this group of patients was 96%. The mean diameter stenosis was reduced from 76 +/- 15% to 2.8 +/- 5%. There was 1 (3.8%) minor stroke in a patient who developed air embolism during baseline angiography. At late follow-up there was no neurologic event in any patient at a mean of 16 +/- 9.5 months after the procedure. Thus, carotid stenting of lesions with contralateral occlusion can be performed successfully with a low incidence of procedural neurologic complications and late stroke.     

Role of carotid sonography as a first examination in the evaluation of patients with transient ischemic attacks and strokes: benefit in relation to age

PURPOSE: We studied the influence of age on the utility of carotid sonography in patients with transient ischemic attacks and strokes. METHODS: The results of Doppler ultrasound examinations of the carotid arteries in 613 consecutive patients with transient ischemic attacks (n = 450) or strokes (n = 163) were analyzed for different age groups. For each patient, the grade of stenosis was scored for the ipsilateral internal carotid artery. The results of the ultrasound examinations were correlated with angiographic findings and findings at endarterectomy. The extent of atherosclerosis for each age group was expressed as the ratio between the number of grade II-IV stenoses (> or = 50%) in the carotid arteries and the number of patients in that group ("atherosclerosis ratio"). RESULTS: Under the age of 40 years, high-grade atherosclerotic stenoses were not found. However, 3 relatively young patients had dissections of the internal carotid arteries. The atherosclerosis ratio exceeded 0.5 for age groups 65-69 years through 80+ years. Among the patients with high-grade stenoses, ischemic heart disease prevented endarterectomy in 63% of patients in age group 80+ years, 44% in age group 75-79 years, and 26% in age group 70-74 years. CONCLUSIONS: Carotid sonography did not detect any significant atherosclerotic changes in young patients but was useful for diagnosing other etiologies of ischemic cerebral disease, eg, carotid dissection. At the other end of the spectrum, the impact of carotid sonography on patient management appears to be limited in patients over the age of 70 years. Carotid sonography seems to be most useful for patients 40-69 years old.     

Carotid endarterectomy for asymptomatic carotid artery stenosis: patients with severe bilateral disease a high risk subgroup

Carotid endarterectomy if advised for asymptomatic disease must be associated with a low peri-operative morbidity and mortality and satisfactory long-term results. Over a 12 year period between 1978-1989 181 carotid endarterectomies were performed on 163 patients with asymptomatic carotid artery stenosis. There were 112 males and 51 females with a mean age of 64.9 years. All patients had a high-grade lesion (> 70% stenosis). The combined operative mortality and stroke rate was 2.8%. On long-term follow up six patients suffered a stroke. Only one patient however sustained a stroke in the same territory as the previously operated carotid artery. Four years following surgery 78% of patients were alive. Carotid restenosis or occlusion occurred in 8.3% of the remaining patients, all of whom were asymptomatic. All the immediate postoperative strokes occurred in patients with severe bilateral carotid artery disease. These patients with severe bilateral disease appear to constitute a high risk sub-group for peri-operative stroke. The role of 'normal pressure-hyperperfusion breakthrough' syndrome as the presumed aetiology of two of the postoperative cerebral haemorrhages is discussed.     

Critical carotid artery stenosis: diagnosis, timing of surgery, and outcome

PURPOSE: Patients with critical carotid artery stenoses have been considered to be at high risk for carotid artery occlusion necessitating urgent or emergency endarterectomy once the stenosis is identified. Included in this group of patients are those with carotid string sign or atheromatous pseudoocclusion (APO). This review was conducted to determine the impact of the severity of stenosis including APO on the treatment and outcome of patients undergoing carotid endarterectomy. METHODS: The records of 203 consecutive carotid endarterectomies performed in 197 patients were reviewed in detail. Patients were stratified into a critical stenosis group (80% to 99% diameter) and noncritical stenosis group based on noninvasive vascular laboratory and carotid arteriography results. Comparisons were performed of demographic data, atherosclerotic risk factors, carotid artery disease presentation, interval between arteriography and endarterectomy, operative details, and surgical results between the critical and noncritical groups and between patients in the critical group with and without APO. RESULTS: Carotid endarterectomies were performed on 91 critical carotid artery stenoses and 112 noncritical stenoses. The groups did not differ significantly with regards to demographics, risk factors, carotid artery disease presentation, mean back pressure, and operative use of shunt or patch closure. For the critical group the interval between arteriography and endarterectomy was 8.63 +/- 2.38 days compared with 9.64 +/- 2.14 days for the noncritical group (mean +/- SEM, p = 0.75). No patient in either group progressed to occlusion in the interval between arteriography and endarterectomy. Perioperative strokes occurred in two patients (2%) in the critical group and four patients (3.6%) in the noncritical group (p = 0.09). Likewise, no significant difference was demonstrated in these variables when comparing patients with critical carotid artery stenosis and APO with those without APO. CONCLUSIONS: The presence of a critical carotid artery stenosis including APO did not impact on the treatment or outcome of patients requiring endarterectomy nor did it imply the need for emergency intervention to prevent thrombosis. Surgical intervention can proceed after evaluation and optimization of comorbid conditions without undue concern for interval thrombosis.     

What's new in stroke?

More than 30,000 strokes occur each year in Texas, even though most strokes can be prevented by currently available and well-tolerated therapies. Antiplatelet therapy with aspirin or ticlopidine reduces stroke by about 25% in many patients with transient ischemic attack or initial stroke. Warfarin should not be used routinely for primary cerebrovascular disease but is useful to prevent cardioembolic stroke. Carotid endarterectomy is highly beneficial for patients with symptomatic, high-grade carotid stenosis, but its value for lesser degrees of symptomatic carotid plaque and for asymptomatic stenosis is less clear. Patients with nonvalvular atrial fibrillation have a substantial risk for stroke; most should be treated with warfarin. Risk-factor management (eg, control of hypertension, cessation of smoking, and treatment of hyperlipidemia) is as important as antithrombotic or surgical therapies for most patients with threatened stroke. Treating isolated systolic hypertension in elderly patients reduces stroke risk. Determining the cause of threatened stroke strongly influences preventive management. The tools are at hand to prevent most strokes; the challenge remains to apply them optimally.     

Carotid artery repair for radiation-associated atherosclerosis is a safe and durable procedure

OBJECTIVE: The development of carotid atherosclerosis after neck irradiation is well documented. There has been concern about the safety and durability of carotid artery repair through a radiated field. The objective of this report is to describe the immediate and long-term results of a series of cases collected in a 13-year interval. METHODS: From 1984 to 1997, 24 patients underwent 26 carotid artery operations. All the patients had undergone prior radiation therapy at a mean interval of 17 years, with an average radiation dose of 6300 rad. Severe scarring of the skin or radiation fibrosis were present in two thirds of the patients, with 4 patients having permanent tracheostomies. The indications for carotid surgery included cerebral or monocular transient ischemic attack (58%), asymptomatic high-grade stenosis (27%), prior stroke (12%), and tumor invasion of the carotid artery (4%). General anesthesia was used with selective shunting on the basis of carotid artery back pressure or electroencephalography monitoring. Patch angioplasty closure was used in 79% of the patients. The operations included standard carotid endarterectomy (n = 20), external carotid endarterectomy (n = 2), carotid patch angioplasty alone (n = 2), aortocarotid bypass grafting (n = 1), and carotid interposition grafting (n = 1). Four patients required skin grafting or myocutaneous flaps. RESULTS: No deaths or strokes occurred within 30 days of the operations. Six patients had transient cranial nerve palsy, and two had wound infections. The patients were followed from 1 to 156 months, with six patients being followed for longer than 18 months. No strokes were seen at late follow-up examination. Duplex scan examination documented one occlusion, in a patient with primary closure, and two restenoses, one of which necessitated reoperation. The remainder of the grafts were widely patent. CONCLUSIONS: Carotid surgery after neck irradiation is safe and durable. The long-term patency rates and the protection against subsequent neurologic events are similar to the results obtained in the absence of radiation therapy. Problems of wound healing were not found in this series.     

Symptomatic recurrent carotid stenosis and aneurysmal degeneration after endarterectomy

BACKGROUND: Aneurysmal degeneration of a carotid reconstruction was not recognized until the patient, who was known to have recurrent carotid artery stenosis, had a thromboembolic stroke. This sequelae of carotid endarterectomy is a serious complication, associated with a high morbidity and mortality rate. This review was conducted to establish the risk of transient ischemic attack and stroke for patients found to have recurrent carotid stenosis associated with aneurysmal degeneration of the carotid artery after endarterectomy. METHODS: A case is reported, and 100 literature references of aneurysmal degeneration of the carotid artery after endarterectomy were reviewed. RESULTS: False aneurysm from anastomotic disruption was the most common presentation identified in the cases reviewed. Nineteen of the patients had a significant neurologic event; however, three (50%) of six patients with aneurysm and recurrent carotid artery stenosis had a transient ischemic attack or stroke. CONCLUSIONS: The incidence of neurologic symptoms is markedly increased when recurrent carotid artery stenosis is associated with carotid aneurysm. During postoperative surveillance after endarterectomy, the identification of recurrent carotid artery stenosis requires evaluation for aneurysmal degeneration of the carotid artery with duplex scanning. These patients are at significant risk for transient ischemic attack and stroke. This rare complication merits operative repair.     

A surgical approach to coexistent coronary and carotid artery disease

OBJECTIVE: To assess the early results of combined coronary artery bypass graft surgery and carotid endarterectomy. DESIGN: Retrospective and ongoing analysis of patients who underwent combined coronary artery bypass graft surgery and carotid endarterectomy. SETTING: Cardiothoracic unit in a London teaching hospital. PATIENTS: From June 1987 to March 1995, 64 patients were identified. They were patients who were scheduled to have coronary artery bypass graft surgery or required urgent coronary revascularisation and who were found to have significant coexistent carotid disease. (Unilateral carotid stenosis > 70%, bilateral carotid stenosis > 50%, or unilateral carotid stenosis > 50% with contralateral occlusion.) INTERVENTIONS: Both procedures were performed during one anaesthesia: the carotid endarterectomy was performed first without cardiopulmonary bypass. After completion of carotid endarterectomy, coronary artery bypass graft surgery was performed. MAIN OUTCOME MEASURES: The incidence of stroke, transient ischaemic attack, and myocardial infarction in the early postoperative period was analysed. RESULTS: Myocardial revascularisation was successful in all 64 patients. There were no perioperative infarcts. In three patients (4.7%) a new neurological deficit developed postoperatively: two recovered fully before hospital discharge. CONCLUSIONS: Combined coronary artery bypass graft surgery and carotid endarterectomy were performed safely and with good results.     

Outcome of moderate carotid artery stenosis in patients who are asymptomatic

PURPOSE: The incidence rate of disease progression and stroke after the diagnosis of a moderate (50% to 79%) carotid stenosis was determined by means of color-flow duplex scanning. METHODS: During a 4-year period, 344 male veterans with moderate internal carotid artery stenoses, on one or both sides, were examined at regular intervals for a mean period of 25 months. Carotid color-flow scans were obtained semiannually. Clinical follow-up was performed to determine the incidence rate of amaurosis fugax, transient ischemic attacks, nonhemispheric symptoms, and strokes. RESULTS: New neurologic symptoms developed in 75 patients (21.8%). Fifty-one (14.8%) had ipsilateral symptoms during follow-up: 18 amaurosis fugax (5.2%), 14 transient ischemic attacks (4%), 5 nonhemispheric symptoms (1.4%), and 14 strokes (4%). Twenty-four patients (6.9%) had contralateral symptoms: 20 strokes (5.8%) and 4 transient ischemic attacks (1.2%). Life-table analysis showed that the annual rate of ipsilateral neurologic events was 8.1%, and the annual rate of stroke was 2.1%. Seventy-five patients (22%) died in the follow-up period. Disease progression to 80% to 99% stenosis or occlusion occurred in 71 of 458 vessels (15.5%). The internal carotid arteries that showed evidence of disease progression had a significantly higher initial peak systolic velocity (251 vs 190 cm/s; P <.0001) and end diastolic velocity (74 vs 52 cm/s; P < 0.0001). Black patients and patients with ischemic heart disease were at a higher risk for disease progression. We could not identify any atherosclerotic risk factors that reliably predicted patients in whom future ipsilateral neurologic symptoms were more likely to develop. However, there was an increased risk of stroke associated with progression of disease. CONCLUSION: Patients who are asymptomatic and who have moderate carotid stenoses are at significant risk for neurologic symptoms and death, but have a relatively low incidence rate of ipsilateral events. The initial flow characteristics in the stenotic vessel are predictive of future disease progression, but they are not helpful in identifying patients in whom symptoms will develop.     

Carotid endarterectomy for asymptomatic carotid stenosis: a meta-analysis

OBJECTIVE: To assess the value of carotid endarterectomy for prevention of stroke in patients with asymptomatic carotid stenosis. DESIGN: Systematic review and meta-analysis of randomised controlled trials in patients with asymptomatic carotid stenosis in which subjects were allocated to carotid endarterectomy or to medical treatment alone. SUBJECTS: Five trials enrolled 2440 patients with stenosis >/ 50%. MAIN OUTCOME MEASURES: Stroke ipsilateral to the stenosis, all strokes, and perioperative complications (stroke or death). RESULTS: In patients who underwent carotid endarterectomy (n=1215) there was a significant reduction in the odds of ipsilateral stroke plus perioperative stroke or death (odds ratio 0.62; 95% confidence interval 0.44 to 0.86), corresponding to a 2% absolute risk reduction over about 3.1 years. The prevalence of stroke in any location was also reduced (0.68; 0.51 to 0.9) in patients undergoing carotid endarterectomy. During the immediate postoperative period there was an increased prevalence of stroke or death among such patients (4.51; 2.36 to 8.64). CONCLUSION: Carotid endarterectomy in patients with asymptomatic carotid stenosis unequivocally reduces the incidence of ipsilateral stroke, though the absolute benefit is relatively small. Given the modest benefit of surgery for unselected patients with asymptomatic carotid artery stenosis carotid endarterectomy cannot be routinely recommended for these patients pending reliable identification of high risk subgroups, and medical management is a sensible alternative for most patients.     

Postoperative stroke and late neurologic complications after carotid endarterectomy

From 1969 through 1973, 335 consecutive patients (mean age, 60 years) underwent 390 carotid endarterectomies using hypercarbic general anesthesia and no carotid shunting. Early neurologic complications were most common among patients with previous neurologic symptoms and among those with subtotal stenosis or occlusion of the contralateral internal carotid artery. The introduction of routine carotid shunting without hypercarbia during a subsequent series of 626 procedures from 1974 through 1978 has been associated with significantly fewer operative strokes in comparable groups of patients. Complete follow-up information during a mean interval of 8.6 years is available for 95% of 325 operative survivors. Late completed strokes have occurred in 17% of patients but have involved the cerebral hemisphere on the side of previous carotid endarterectomy in only 7%. Of 93 operative survivors who had subtotal stenosis of the contralateral internal carotid artery, 45 underwent contralateral endarterectomy as an elective procedure and 48 did not. The late contralateral stroke rates for these two groups of patients were 4% and 16%, respectively, although these differences did not attain statistical significance. Forty-nine (78%) of 63 patients with contralateral internal carotid occlusion have had no late neurologic symptoms following unilateral carotid endarterectomy.     

Asymptomatic carotid artery stenosis and stroke in patients undergoing cardiopulmonary bypass

PURPOSE: This study was undertaken to assess the natural history of carotid artery stenosis in patients undergoing cardiopulmonary bypass (CPB) at a Veterans Administration Medical Center. METHODS: Between January 1989 and August 1993, all patients undergoing CPB were offered preoperative carotid artery ultrasound screening as part of an investigative protocol. Patients were monitored in-hospital for the occurrence of perioperative neurologic deficit. RESULTS: A total of 582 patients underwent carotid artery ultrasound screening. Greater than 50% stenosis or occlusion of one or both internal carotid arteries was present in 130 patients (22%), with 80% or greater stenosis or occlusion of one or both arteries present in 70 patients (12%). In-hospital stroke or death occurred in 12 (2.1%) and 36 (6.2%) patients, respectively. Of the 12 strokes, five were global and seven were hemispheric in distribution. Of the five patients who had global events, none had evidence of carotid artery stenosis. However, of the seven patients who had hemispheric events, five had significant 50% or greater stenosis or occlusion of the internal carotid artery ipsilateral to the hemispheric stroke. Therefore the presence of carotid artery stenosis or occlusion was significantly associated with hemispheric stroke (no stenosis 0.34% vs stenosis 3.8%; p = 0.0072). Furthermore, the risk of hemispheric stroke in patients with unilateral 80% to 99% stenosis, bilateral 50% to 99% stenosis, or unilateral occlusion with contralateral 50% or greater stenosis was 5.3% (4 of 75). No strokes occurred in patients with unilateral 50% to 79% stenosis (n = 52). CONCLUSIONS: It is concluded that carotid atherosclerosis is a risk factor for hemispheric stroke in patients undergoing CPB.     

Unilateral internal carotid arterial occlusion: special considerations

Cases of patients with unilateral internal carotid arterial occlusion and contralateral internal carotid arterial stenosis are reviewed. Forty-two percent presented with a fixed neurological deficit. The deficit was referable to the side of occlusion in 92% and to the side of stenosis in 8%. Eleven percent had a neurological complication following carotid endarterectomy on the side of the stenotic lesion. The neurological complication was referable to the side of stenosis in 67% and to the side of occlusion in 33%. Patients have been followed for an average of 19 months and have not developed any additional TIA's or strokes in the followup period. There may be a role for an extracranial-intracranial bypass (ECIC) on the occluded side prior to an endarterectomy on the stenotic side if a poor collateral situation exists. An ECIC should be done in patients who remain symptomatic following carotid endarterectomy on the stenotic side. These data do not support doing ECIC in asymptomatic patients with unilateral carotid arterial occlusion.     

Effect of salinity on the swimming velocity of the water flea Daphnia magna

BACKGROUND: Cost-effective carotid endarterectomy implies a good outcome; low morbidity, a short hospital stay and selective use of non-invasive preoperative diagnostic tests done alone. METHODS: A solo surgeon's clinical experience with two hundred and eighteen consecutive operations, over seven years, at two Community Hospitals in Northern Virginia. RESULTS: There were three perioperative strokes, of which one resulted in death, for a mortality rate of 0.45%, and a stroke rate of 1.4%. The majority of the operations in the past two years were done on the basis of Duplex ultrasonography and magnetic resonance angiography, but without invasive angiography. General anesthesia, routine use of shunt and use of autogenous vein patch in almost every case was employed. Patients were selectively observed in the Intensive Care Unit postoperatively. Forty eight percent of the series and 75% of the most recent 121 patients operated on in 1995 and 1996 were discharged on the first postoperative day without any need for re-admission to the hospital. CONCLUSIONS: Carotid endarterectomy can be performed with a short hospital stay and an extremely low morbidity and mortality. Carotid endarterectomy is a highly effective surgical procedure both from the medical and economy stand-points.     

Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators

BACKGROUND: Previous studies have shown that carotid endarterectomy in patients with symptomatic severe carotid stenosis (defined as stenosis of 70 to 99 percent of the luminal diameter) is beneficial up to two years after the procedure. In this clinical trial, we assessed the benefit of carotid endarterectomy in patients with symptomatic moderate stenosis, defined as stenosis of less than 70 percent. We also studied the durability of the benefit of endarterectomy in patients with severe stenosis over eight years of follow-up. METHODS: Patients who had moderate carotid stenosis and transient ischemic attacks or nondisabling strokes on the same side as the stenosis (ipsilateral) within 180 days before study entry were stratified according to the degree of stenosis (50 to 69 percent or <50 percent) and randomly assigned either to undergo carotid endarterectomy (1108 patients) or to receive medical care alone (1118 patients). The average follow-up was five years, and complete data on outcome events were available for 99.7 percent of the patients. The primary outcome event was any fatal or nonfatal stroke ipsilateral to the stenosis for which the patient underwent randomization. RESULTS: Among patients with stenosis of 50 to 69 percent, the five-year rate of any ipsilateral stroke (failure rate) was 15.7 percent among patients treated surgically and 22.2 percent among those treated medically (P=0.045); to prevent one ipsilateral stroke during the five-year period, 15 patients would have to be treated with carotid endarterectomy. Among patients with less than 50 percent stenosis, the failure rate was not significantly lower in the group treated with endarterectomy (14.9 percent) than in the medically treated group (18.7 percent, P=0.16). Among the patients with severe stenosis who underwent endarterectomy, the 30-day rate of death or disabling ipsilateral stroke persisting at 90 days was 2.1 percent; this rate increased to only 6.7 percent at 8 years. Benefit was greatest among men, patients with recent stroke as the qualifying event, and patients with hemispheric symptoms. CONCLUSIONS: Endarterectomy in patients with symptomatic moderate carotid stenosis of 50 to 69 percent yielded only a moderate reduction in the risk of stroke. Decisions about treatment for patients in this category must take into account recognized risk factors, and exceptional surgical skill is obligatory if carotid endarterectomy is to be performed. Patients with stenosis of less than 50 percent did not benefit from surgery. Patients with severe stenosis (> or =70 percent) had a durable benefit from endarterectomy at eight years of follow-up.     

Is impaired cerebral vasomotor reactivity a predictive factor of stroke in asymptomatic patients?

BACKGROUND AND PURPOSE: Identification of the subgroup of asymptomatic patients with severe internal carotid artery stenosis and high risk of stroke has important clinical implications. Cerebral vasomotor reactivity provides information regarding intracranial hemodynamic features and might have a prognostic value in predicting cerebrovascular ischemic events, especially in patients with carotid stenosis. The aim of our study was to assess the cerebral vasomotor reactivity in asymptomatic patients with carotid stenosis and evaluate its role in stroke occurrence. METHODS: Cerebral vasomotor reactivity was assessed using transcranial Doppler ultrasonology and the Diamox test (intravenous administration of 1.0 g acetazolamide) in 44 asymptomatic patients with severe (> 70%) internal carotid artery stenosis. Patients were followed up prospectively (mean, 2 years). RESULTS: Cerebral vasomotor reactivity was estimated as good (> 40% increase of blood flow velocity in the middle cerebral artery ipsilateral to the carotid stenosis after undergoing the Diamox test) in 23 patients; it was impaired in the other 21. During the follow-up period, the overall annual rate for ipsilateral stokes was 2.3%; it was 7.9% for all ischemic cerebral events. No strokes or transient ischemic attacks occurred in the former group, but there were 7 cerebral ischemic events (2 strokes [1 fatal] and 5 transient ischemic attacks) in the latter group. There was a statistically significant correlation between cerebral ischemic events and impaired cerebral vasomotor reactivity (P = .009). CONCLUSIONS: The data of this preliminary study suggest an important role of impaired cerebral vasomotor reactivity in predicting ischemic cerebral events. Preventive vascular surgery might be considered in this high-risk subgroup of asymptomatic patients with severe carotid stenosis.     

Role of transcranial Doppler and stump pressure during carotid endarterectomy

BACKGROUND AND PURPOSE: The aim of our study was to clarify the pathophysiology of perioperative cerebral complications during carotid endarterectomy in our series. METHODS: By means of transcranial Doppler ultrasonography and stump pressure measurement, we monitored 112 patients who underwent carotid endarterectomy under general anesthesia for symptomatic or asymptomatic severe carotid stenosis. RESULTS: Of 18 patients who underwent carotid endarterectomy with intra-arterial shunt, 2 (11.1%) developed an ischemic stroke. Of the other 94 patients, one suffered a nucleocapsular hemorrhage and 5 had cerebral ischemic complications. In these 5 patients, the duration of clamping was significantly longer (mean +/- SD, 16.4 +/- 1.1 versus 12.7 +/- 2.6 minutes; P = .0019), and the decrease of middle cerebral artery mean velocity on clamping was significantly greater (mean +/- SD, 56.4 +/- 4.9% versus 28.8 +/- 20.2%; P = .0031), while stump pressure was not significantly different. Microembolic signals were recorded in 70 patients (62.5%) and were not associated with cerebral ischemic complications. The 7 patients who developed cerebral ischemic complications had a significantly higher percentage of stenosis in the contralateral internal carotid artery (mean +/- SD, 82.0 +/- 17.8% versus 29.3 +/- 36.4%; P = .0018). CONCLUSIONS: The results of our study suggest that the major complications of carotid endarterectomy may be due to hemodynamic factors. Stump pressure alone is not a reliable indicator of hemodynamic changes that predict cerebral ischemia. Particulate microembolism may cause more subtle changes in cerebral parenchyma, but further studies are needed to clarify this point.