Carotid endarterectomy for cerebrovascular insufficiency: long-term results in 592 patients followed up to thirteen years

Combined Endovascular and Surgical Treatment of Chronic Carotid Artery Occlusion: Hybrid Operation

Objectives

The optimal treatment choice of chronic carotid artery occlusion (CAO) remains inconclusive. This study was aimed at exploring the safety and effectiveness of hybrid surgery in the treatment of CAO and at determining predictors for successful recanalization.

Methods

In this study, we enrolled 37 patients with CAO who underwent hybrid surgical treatment during the period 2016–2018. We extracted and analyzed patients' demographic data, disease characteristics, surgical success rates, perioperative complications, and prognosis.

Results

A total of 37 patients with symptomatic CAO underwent hybrid surgical treatment. Thirty cases (81.1%) were successfully recanalized, while seven were not. Blood reflux after carotid endarterectomy occurred in 18 patients (60%) of the success group and 1 (14.3%) of the failure group (OR, 9.0; 95% CI, 0.95-54.5; P = 0.042). The rate of distal ICA reconstruction below the clinoid segment was 20 (66.7%) in the success group and 1 (14.3%) in the failure group (OR, 12.0; 95% CI, 1.3-113.7; P = 0.029). In patients with successful recanalization, no ischemic events occurred after surgery and during follow-up, but restenosis of >50% was found in one case. In the failure group, two patients experienced recurrent ischemic events during follow-up. Perfusion imaging in successful recanalization cases is significantly improved, preoperative I/C ratio was 1.44 (IQR 1.27-1.55), and postoperative 1.12 (IQR 1.05-1.23). National Institutes of Health Stroke Scale (NIHSS) score of successful recanalization cases was 5.35 (2.26) before surgery and 2.03 (1.40) at 6 months (P < 0.01).

Conclusion

Hybrid surgery might be a safe and effective way to treat CAO. Distal internal carotid artery reconstruction to below the clinoid segment and blood reflux after carotid endarterectomy are predictors of successful recanalization.

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

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

Carotid Endarterectomy Under Local Anesthesia: The Safer Alternative?

Carotid endarterectomy can be successfully accomplished using either local or general anesthesia. The purpose of this study was to attempt to discern any differences in perioperative morbidity associated with the two anesthetic tech niques. A retrospective review was undertaken of 324 consecutive carotid en darterectomies performed by fifteen surgeons between 1979 and 1985. There were no significant differences in preoperative cardiac, pulmonary, or renal risk factors between the two anesthetic groups. Postoperative fever (p < 0.005), pulmonary complications (p < 0.05), and neurologic morbidity (p < 0.05) oc curred significantly more frequently in the general anesthesia group. The dura tion of postoperative hospitalization was shorter (p < 0.0005) in the local anes thetic cohort (3.1 ± 2.3 days) than in the general anesthetic group (5.1 ± 8.07 days). Local anesthesia for carotid endarterectomy appeared to result in less morbidity and shorter hospitalization when compared with general anesthesia. There did not appear to be any cerebral protective effect of general anesthesia during carotid endarterectomy.

Simultaneous Bilateral Carotid Endarterectomy: A Revision of Concepts and Strategies

The results of 156 bilateral cases of carotid endarterectomy are reported: 71 patients had staged operations and 85 patients had simultaneous endarterectomies.

The results in these two groups of bilateral cases were very similar. In each of the two groups no patient died and the major neurologic complications (stroke) were less than 2% in regard to patient risk, and therefore less than 1% in regard to procedure risk.

Indications for and against bilateral carotid surgery as a simultaneous or a staged procedure are discussed. The parameters for selecting patients likely to undergo simultaneous surgery are indicated. The main parameter to consider is the probability for the patient to have a serious post-operative hyperperfu sion, especially if a cerebral ischemia coexists.

Carotid Endarterectomy: The Gold Standard

Carotid endarterectomy has been firmly established as the gold standard of therapy for symptomatic and asymptomatic patients with severe carotid stenosis, provided surgical complication rates are within prescribed limits. The procedure-related risk of stroke/death should be < 3% in asymptomatic patients and < 6% in symptomatic patients. New investigational therapies such as balloon angioplasty and stenting for carotid stenosis should be evaluated against the same standard.

Direct endovascular recanalization of chronic carotid occlusion: should we do it? Case report

BACKGROUND AND IMPORTANCE

Patients with chronic carotid artery occlusion face a significant risk of stroke. It is believed that treatment is indicated if medical therapy fails or even as prophylaxis in high-risk patients. Direct surgical repair with carotid endarterectomy has a considerable failure rate and significant associated risks. Indirect repair with an extracranial-to-intracranial bypass has become the mainstay of surgical treatment. In this case study, the authors assess the feasibility of direct endovascular recanalization in the setting of chronic carotid occlusion, and discuss technical nuances and indications in comparison with the world literature and alternative options.

CLINICAL PRESENTATION

Two patients presented with symptomatic, chronic, complete occlusion of the proximal carotid artery. The duration of documented occlusion exceeded 3 years in one patient and 6 months in the other.

METHODS

Endovascular recanalization was attempted using extracranial and intracranial stenting with proximal protection (flow arrest/reversal). Both patients had an excellent radiographic result, improving from Thrombolysis in Cerebral Infarction (TICI) grade 0 (no perfusion) to grade 3 (complete perfusion). The first patient's clinical symptoms resolved. The second patient remained unchanged with a mild facial droop.

CONCLUSION

These preliminary results show potential for the endovascular management of this complicated disease. Long-term results and more data will determine the ultimate place of endovascular recanalization for symptomatic chronic carotid occlusion among other therapies.

RACE to protect brains

INTRODUCTION

Rapid-access carotid endarterectomy (RACE) is an evidence-based treatment for symptomatic carotid stenosis. Our vascular centre aims to provide this service within 48 h of symptoms in appropriate patients. This study audits safety and efficacy of the first year of RACE.

SUBJECTS AND METHODS

A clear trust protocol was publicised for the RACE pathway. A prospective database was established for all carotid endarterectomies (CEAs) performed. Outcomes were compared between elective (ECE) and rapid-access operations.

RESULTS

In 1 year, 96 patients received CE; 20 were performed urgently. There were no significant differences in age or gender between ECE and RACE groups. Twenty-three (30%) of ECE were for asymptomatic stenoses; no other significant differences in surgical indication were seen. Of symptomatic ECE, 43% were for completed stroke versus 55% for RACE. Median delay between diagnosis and surgery was 113 days for elective and 2 days for RACE patients. There was one death following ECE (1.3%) and one stroke after RACE (5%), all not significant. Anaesthetic method did not influence outcome. The main reasons for delaying surgery in RACE patients were optimisation of patient fitness and availability of theatre time.

CONCLUSIONS

The RACE pathway dramatically reduces delay without compromising patient safety. In the first year of service, we have treated 50% of suitable patients within 48 h. Further education of patients and colleagues should reduce delay and improve outcomes for symptomatic carotid disease.

Cerebral oximetry does not correlate with electroencephalography and somatosensory evoked potentials in determining the need for shunting during carotid endarterectomy

OBJECTIVE

Several reports in the literature have described the value of regional cerebral oximetry (rSO(2)) as a neuromonitoring device during carotid endarterectomy (CEA). The use of rSO(2) is enticing because it is simpler and less expensive than other neuromonitoring modalities. This study was performed to compare the efficacy of rSO(2) with electroencephalography (EEG) and median nerve somatosensory evoked potentials (SSEP) in determining when to place a shunt during CEA.

METHODS

From October 2000 to June 2006, 323 CEAs were performed under general anesthesia by six surgeons. Shunting was done selectively on the basis of EEG and SSEP monitoring under the auspices of an intraoperative neurophysiologist. All patients were retrospectively reviewed to see if significant discrepancies existed between EEG/SSEP and rSO(2).

RESULTS

Twenty-four patients (7.4%) showed significant discrepancies. Sixteen patients showed no significant EEG/SSEP changes, but profound changes occurred in rSO(2), and no shunt was placed. In seven patients there was no change in rSO(2) but a profound change occurred in EEG/SSEP, and shunts were placed. In one patient early in the series, the EEG and SSEP were unchanged but the rSO(2) dropped precipitously, and a shunt was placed. In the 299 patients who showed no discrepancies, 285 were not shunted and 14 required a shunt. Two strokes occurred in the entire series (0.6%), none intraoperatively. Shunts were placed in 23 patients (7%). The sensitivity of rSO(2) compared with EEG/SSEP was 68%, and the specificity was 94%. This gave a positive-predictive value of 47% and a negative-predictive value of 98%.

CONCLUSIONS

Relying on rSO(2) alone for selective shunting is potentially dangerous and might have led to intraoperative ischemic strokes in seven patients and the unnecessary use of shunts in at least 16 patients in this series. The use of rSO(2) adds nothing to the information already provided by EEG and SSEP in determining when to place a shunt during CEA.

Urgent carotid surgery

Early intervention may be better

Risk factors for perioperative myocardial ischemia in carotid artery endarterectomy

OBJECTIVE

To identify variables associated with perioperative myocardial ischemia in patients undergoing carotid artery endarterectomy (CEA).

DESIGN

Prospective, observational study.

SETTING

University-affiliated hospital operating room and intensive care unit.

PARTICIPANTS

One hundred twenty-eight consecutive patients who underwent CEA during a 7-year period.

INTERVENTIONS

Patients had general anesthesia with sevoflurane or isoflurane. CEA was performed by standard methods with shunting if clinically indicated. Holter electrocardiogram (ECG) monitoring was performed during surgery and 24 hours after surgery.

MEASUREMENTS AND MAIN RESULTS

The incidence of perioperative myocardial ischemia was examined, and perioperative risk factors were analyzed. Nineteen patients (15%) showed significant perioperative ECG abnormalities indicative of myocardial ischemia (10 patients during surgery, 12 patients after surgery, and 3 patients both during and after surgery). Multivariate analysis showed perioperative myocardial ischemia to be significantly associated with a history of angina (odds ratio, 11.68; 95% confidence interval, 2.64-51.70) and a history of hypertension (odds ratio, 14.08; 95% confidence interval, 1.51-131.04).

CONCLUSION

The data indicate that perioperative myocardial ischemia defined as an ECG abnormality does not often occur in patients undergoing CEA. However, angina and hypertension may be important risk factors warranting further investigation.

From Hippocrates to Palmaz-Schatz, the history of carotid surgery

The extracranial carotid artery is the most common site for peripheral vascular procedures. Although the association of carotid disease and neurologic dysfunction was understood by the ancient Greeks, over 1700 years would pass before the relevant anatomy was described. In the 16th and 17th centuries, attempts at treatment of carotid injury and aneurysm by ligation were met with extremely high rates of stroke and death. It is not until the mid 20th century, with the introduction of carotid angiography and improved vascular surgical techniques, that the era of reconstructive carotid surgery begins. We present a synopsis of the history of carotid surgery from ancient times to present day.

The evolution of extracranial carotid artery surgery as seen by one surgeon over the past 40 years

Carotid endarterectomy is one of the most common vascular and neurosurgical operations. Controversies regarding its indications and safety have required several decades before general resolution, while its methodology is still debated. The first operations are described with particular emphasis on the epic successful procedure in 1954 by Eastcott and Rob. Early procedures were on patients with frank strokes with poor results. The development of carotid endarterectomy was slow because neurologists were unsure of its effectiveness and safety as the mortality and stroke results recorded by untrained surgeons were unacceptable. It was not until some 35 years after its introduction that randomised controlled trials, both in North America and Europe, defined its indications and demonstrated its benefits for both symptomatic and asymptomatic carotid stenosis. Clamping of the carotid vessels, required during endarterectomy, may result in various degrees of cerebral ischaemia. Methods to determine which patients need shunting are compared. The author has employed local neck block anesthesia since 1972, which is the only method that provides constant neurological assessment for selective shunting during carotid cross clamping. Evidence is presented showing that local anaesthesia also reduces complications of general anaesthesia, especially myocardial infarction. The technique of neck block, conventional endarterectomy and two varieties of eversion endarterectomy for carotid disease are described. Each of these techniques of endarterectomy is advantageous in certain circumstances, suggesting that vascular surgeons should ideally be proficient in each. Likewise, the management of early stroke after operation, stenotic or occluded external carotid the presence of retinal Hollenhorst plaques, and the totally occluded internal carotid, is presented. Finally, observations on some famous figures who suffered from cerebrovascular complications secondary to carotid disease and what effect it may have had on world history is discussed.

Comparison of nonneurological events in high-risk patients treated by carotid angioplasty versus endarterectomy

OBJECTIVE

To compare results of carotid angioplasty and stenting (CAS) with carotid endarterectomy (CEA) in high cardiac risk patients.

METHODS

Patients ineligible for carotid revascularization by North American Symptomatic Carotid Endarterectomy Trial/Asymptomatic Carotid Atherosclerosis Study criteria were treated with CAS (n = 11) or CEA (n = 10).

RESULTS

Significant numbers had cardiac (CAS 72%, CEA 60%; P = 0.66) and hypertensive (CAS 82%, CEA 80%; P = 0.64) risk factors. Adverse hemodynamic events were more frequent in the CAS group (CAS 73%, CEA 20%; P = 0.03). Major complications were noted in 1 patient in each group (CAS, myocardial infarction; CEA, death). Postoperative stay was similar (CAS 2.1 +/- 1.4, CEA 1.8 +/- 1.1 days; P = 0.60). However, 4 in the CAS group were readmitted within 1 month (congestive heart failure 2, myocardial infarction 1, rest pain 1), compared with no new events in the CEA group (P = 0.09).

CONCLUSIONS

Currently, the use of CAS in patients with cardiac risk factors may not be justifiable.

The effect of intraoperative duplex on the management of postoperative stroke

BACKGROUND

Stroke after carotid endarterectomy (CEA) may be a result of intraoperative ischemia, embolism, or thrombosis at the operative site. Intraoperative duplex should eliminate the occurrence of a severe internal carotid artery (ICA) thrombosis and, thus, negate the benefit of reoperation. This article will detail the results of our evolving treatment algorithm for immediate versus delayed post-CEA neurologic deficit (ND).

METHODS

We studied patients who had an ND after CEA from 1988 to 2000. Results. Thirty-two patients (3.2%) had a post-CEA ND (26 related stroke or transient ischemic attack, 6 other); 31 had a satisfactory intraoperative duplex post-CEA, 1 was not tested. Fifteen patients awoke from operation with a related deficit, 5 of whom were re-explored and all had a patent ICA. One patient without lateralizing signs who was not re-explored had extensive thrombosis at postmortem. The remaining 9 all had a duplex-proven patent ICA. Ten patients had a lucid interval before their related ND. Six patients were re-explored and all had thrombosed ICAs; 5 of the 6 improved postthrombectomy. Four patients were not re-explored for various reasons; a carotid thrombosis was not later diagnosed in any of these patients.

CONCLUSIONS

Intraoperative and postoperative duplex has modified our treatment of post-CEA stroke. No longer are all patients re-explored. Patients with a normal intraoperative duplex who awaken with an immediate stroke do not usually have occlusive thrombus and routine re-exploration does not benefit these patients. Patients who have an ND develop after a lucid period may have a thrombosed ICA despite a normal intraoperative duplex, and unless there is a timely normal duplex, re-exploration is recommended and appears to benefit these patients.

Reconstructive surgery of the extracranial arteries

The first carotid endarterectomy (CEA) is usually accredited to Eastcott who reported in 1954 the successful incision of a diseased carotid bulb with end-to-end anastomosis of the internal carotid artery (ICA) to the common carotid artery (CCA). During the following years surgeons were quick to adopt and improve the intuitively attractive procedure. But by the early to mid 1980s several leading neurologists began to question the growing number of CEAs performed at that time. Six major CEA trials were then designed which are now completed or nearing completion. Most conclusive data are available from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) for symptomatic carotid disease, and from the Asymptomatic Carotid Atherosclerosis Study (ACAS) for asymptomatic carotid disease. The key result of these studies is that CEA is beneficial to high grade symptomatic and asymptomatic carotid stenosis. While the benefit in symptomatic disease is clear, it may be negligible in asymptomatic patients suffering from other medical conditions, the most important being coronary artery disease. Since the conclusions from the different studies vary significantly, guidelines and recommendations with regard to CEA have been issued by a number of interest groups, so-called consensus conferences. The best known guidelines are published by the American Heart Association (AHA). However, the practice of interest groups to issue guidelines is currently being criticized, the main reason being that interest groups have different ideas and all claim the right to issue guidelines. At present we recommend CEA for symptomatic high-grade stenosis in patients without significant coincident disease. With regard to asymptomatic stenosis we suggest surgery to otherwise healthy patients if the stenosis is very narrow or progressive. Preoperative evaluation has changed over the years. Currently we recommend duplex sonography in combination with intra- and extracranial magnetic resonance angiography (MRA). Concurrent coronary artery disease is a major consideration in the perioperative management, and the use of a specific algorithm is recommended. Surgery is performed under general anaesthesia with intraoperative monitoring such as electroencephalography (EEG) and transcranial Doppler (TCD). A temporary intraluminal shunt is used selectively if after cross-clamping the flow velocity in the middle cerebral artery (MCA) falls to below 30 to 40% of baseline. For years we employed routine barbiturate neuroprotection during cross-clamping. At the present time we use barbiturate selectively, if the flow velocity in the MCA falls to below 30 to 40% of baseline and if the use of a temporary intraluminal shunt is not possible due to difficult anatomic conditions. The reason to abandon systematic barbiturate protection was to accelerate recovery from anaesthesia. Our patients are monitored overnight on the ICU or a surveillance unit. Routine hospitalization after surgery is 5 to 7 days with a control duplex sonography being performed prior to discharge. A number of details with regard to surgical technique and perioperative management are a matter of discussion. Our surgical routine is described here step by step. Such management resulted in 6 major complications among the 402 cases with 4 of cardiopulmonary and 2 of cerebrovascular origin. For the future we can expect the development of percutaneous transluminal techniques competing with standard carotid endarterectomy. At the present time several comparative studies are under way. Irrespective of the technical approach to treat carotid stenosis, several other issues have to be clarified before long. One of the major unresolved items is the timing of treatment after completed stroke. In this regard prospective trials need to be performed. Although numerically not as important as carotid stenosis, vertebral artery (VA) and subclavian artery (SA) stenoses are more and more accepted as indication for surgical

Coexistent coronary and cerebrovascular disease: results of simultaneous surgical management in specific patient groups

OBJECTIVE

Results of synchronous combined revascularization were examined in specific patient groups with coexistent coronary and cerebrovascular diseases.

METHODS

Between 1.1.1980 and 31.12.1998, 408 patients underwent a synchronous combined carotid endarterectomy (CEA)+myocardial revascularization (CABG). In 259 (63.5%) patients, carotid disease was asymptomatic. Remaining patients presented with a previous stroke (n=35) or a transient ischemic episode (TIA) (n=114). In 245 (60%) patients, carotid stenosis was bilateral (Group A: bilateral > or =80% stenosis, Group B: contralateral occlusion, Group C: contralateral subcritical disease). A synchronous ipsilateral CEA+CABG was performed in all patients with an unilateral disease (n=163) and also in all Group B (n=33) and Group C (n=142) patients with bilateral disease. A simultaneous bilateral CEA+CABG was performed in 12 high risk Group A patients. Remaining Group A patients (n=58), initially underwent an ipsilateral CEA for most dominant lesion+CABG, soon followed by the contralateral CEA. Results were examined in above specific patient Groups.

RESULTS

Overall combined hospital mortality from stroke+myocardial infarction was 2.45%. No independent predictor of stroke was identified. In general, initial prophylactic CEA, subdued the risk of subsequent strokes for 7-8yr. Predictors of a late stroke were: progression of bilateral (P=0.007) and intracranial (P=0.04) cerebrovascular disease. Highest risk of an early stroke was recorded in Group A patients. A composite high risk group of patients with multiple risk factors (n=155) demonstrated a higher risk of both early and late strokes, as compared to the remaining patients (n=253) (P<0.04). Observed risk of early and late strokes, in specific patient groups was lower than standard predictions.

CONCLUSIONS

A regular use of combined approach was justified in the above patient groups.

Repair of carotid endarterectomy with a collagen-impregnated fabric graft

Saphenous vein patch closure of carotid endarterectomies may decrease the risk of acute postoperative occlusion and recurrent stenosis. However, the disadvantages of a vein patch include postoperative rupture and pseudoaneurysm formation.

OBJECT

The authors sought to assess the effectiveness of collagen-impregnated fabric grafts as substitutes for saphenous vein grafts.

METHODS

In this report the authors prospectively analyzed 290 consecutive carotid endarterectomies in which a secondary closure was accomplished using a knitted double-velour graft. The 30-day major neurological morbidity and mortality rate was 1.7%. There were no postoperative occlusions or wound hematomas. The rate of recurrent carotid artery stenosis was less than 1%, and the graft site in one patient became infected.

CONCLUSIONS

For surgeons who prefer a secondary closure of carotid endarterectomies, the synthetic graft may prove to be a viable alternative to a saphenous vein.

Carotid endarterectomy in patients less than 50 years old

PURPOSE

The purpose of this study was to compare the results of carotid endarterectomy (CEA) in a young population with premature atherosclerosis with the results of an older control group, examining perioperative morbidity and mortality data, recurrent stenosis and symptoms, late stroke, and survival data.

METHODS

We retrospectively studied 26 patients less than 50 years old (mean, 43.2 +/- 3.8 years) and 30 patients greater than 55 years old (mean, 69.1 +/- 7.4 years) who underwent CEA during the same time period. Data were obtained regarding demographics, atherosclerotic risk factors, indication for CEA, perioperative complications, recurrent stenosis and symptoms, late stroke, and survival.

RESULTS

Smoking was more prevalent among young patients who underwent CEA (92% vs 70%; p = 0.036). Young patients were also more likely to be symptomatic at presentation (92% vs 57%; p = 0.003). The perioperative mortality rate (0% vs 0%) and neurologic morbidity rate (0% vs 3%; p = 1.000) were low for the study patients. During a mean follow-up of 67 +/- 42.7 months, there was no significant difference in survival rate (5-year survival rate, 93% vs 81%; p = 0.373), rate of late ipsilateral (4% vs 3%) and contralateral (4% vs 3%) stroke, restenosis and occlusion (26.9% vs 14.3%), recurrent symptoms (22% vs 17%), reoperation (11.5% vs 5.7%), or contralateral disease (17% vs 23%) development that required surgery for the study or the control cohorts.

CONCLUSIONS

Our data show that there is a high incidence of smoking and symptomatic presentation among young patients in whom carotid occlusive disease develops. CEA may be performed in young patients with low perioperative morbidity and mortality rates. Recurrent disease, late stroke, and survival rates are not significantly different than for older patients. Follow-up with serial duplex ultrasound and reoperation for symptomatic and high-grade asymptomatic restenosis may decrease the risk of late stroke.

Cardiac events after combined surgery for coronary and carotid artery disease

OBJECTIVE

To evaluate serious cardiac events after combined (either single or two stage) coronary artery surgery (CAS) and carotid endarterectomy (CEA) for concomitant coronary and carotid artery disease.

METHODS

We have analyzed our 15 year experience (January 1981-September 1996) with 201 consecutive patients operated on using both approaches. Group A consisted of 48 patients with the single-stage procedure, while in group B (153 patients), two stage procedure was carried out, either as carotid endarterectomy (CEA), followed by coronary artery bypass surgery (CAS) (group B1- 103 patients), or as CAS followed by CEA (group B2- 50 patients). Five patients from B1 group died after the CEA procedure, but were included, despite the fact they never reached the second stage. Left main coronary artery disease was found in 41 patients (20.4%), poor left ventricular function in 49 (24.4%) previous MI in 133 (66.2%), while 136 (67.7%) were in NYHA functional class III or IV. Bilateral carotid involvement was present in 61 patients (30.3%). Unstable angina was more prevalent in groups A and B2 (P < 0.0001). NYHA class III/IV in group A (versus B1, P = 0.001 and versus B2, P = 0.02), low ejection fraction in groups A and B2 (P < 0.0001), bilateral carotid stenosis in group B1 (versus A, P = 0.003 and versus B2, P < 0.0001), and ulcerated plaque in group B1 (P < 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management.

RESULTS

Early mortality for the entire group was 5.5% (11/201) 6.2% in group A, 7.8% in group B1 and 0% in group B2, respectively; (P > 0.05). Serious morbidity occurred in 7.5% of patients (8.3% in group A, 7.8% in group B1 and 6% in group B2, respectively; P > 0.05). Univariate analysis revealed only bilateral carotid stenosis to influence early outcome (P = 0.04).

CONCLUSION

Patients with concomitant coronary and carotid artery disease have relatively good immediate operative results, providing all existing lesions are corrected. Despite it did not reach the statistical significance, cardiac events were less frequent in groups A and B2 indicating possible protective effect of prior CAS in patients with concomitant disease.

Minimally invasive coronary artery bypass techniques as adjunct to extracardiac procedures

BACKGROUND

Surgical management of coronary artery disease has improved dramatically over the last decades in terms of short- and long-term results. Nevertheless, elderly patients (more than 75 years); patients with reduced ejection fraction (less than 0.25), heavily calcified aorta, or coexisting noncardiac diseases; and patients requiring cardiac reoperation have an increased perioperative risk when operated on with cardiopulmonary bypass. Successful minimally invasive coronary artery bypass grafting without cardiopulmonary bypass has been reported in selected cases.

METHODS

In 8 of 40 high-risk patients undergoing operation on a beating heart, minimally invasive coronary bypass grafting was combined with vascular (carotid endarterectomy, n = 3; aortic replacement, n = 2) and abdominal procedures (a second look after combined pancreas and kidney transplantation) or defibrillator implantations (n = 2).

RESULTS

Postoperatively, there was no mortality, no morbidity, and no blood transfusion. Patients are free of symptoms at an average follow-up time of 5.5 +/- 5 months.

CONCLUSIONS

Our results indicate that minimally invasive coronary artery bypass grafting technique can be particularly useful if noncardiac procedures have to be performed in high-risk patients with significant coronary artery disease.

Myocardial ischaemia, infarction and cardiac-related death following carotid endarterectomy: risk assessment by thallium myocardial perfusion scan compared with clinical examination

Risk factors in 402 patients undergoing 447 carotid endarterectomies were reviewed to see whether the presence of coronary artery disease before operation influenced the likelihood of perioperative cardiac complications. A second aim of the study was to assess whether myocardial thallium scintigraphy was valuable for preoperative assessment. Fourteen patients developed postoperative cardiac complications, six (1.3%) of which were fatal. Four of these deaths occurred in 60 patients undergoing combined carotid-coronary revascularization (6.6%). In 387 carotid endarterectomies without simultaneous coronary revascularization, there were two deaths from myocardial infarcts (0.5%). These fatalities and other cardiac complications occurred in 204 patients with preoperative clinical or ECG evidence of coronary artery disease. In 198 patients with no preoperative evidence of coronary disease there were no fatalities and only one patient with reversible postoperative myocardial ischaemia (0.4%). It is concluded that carotid endarterectomy under general anaesthesia is unlikely to be followed by cardiac complications when there is no preoperative evidence of coronary artery disease. When coronary disease is detected before operation, postoperative cardiac complications occur after 5.6% of operations, including 0.9% fatalities. When coronary artery disease is severe enough to warrant combined carotid-coronary reconstruction, the perioperative mortality rate was 6.6%, all the deaths being cardiac-related. When myocardial thallium scintigraphy was normal, postoperative cardiac complications did not occur.

Does the choice of material influence early morbidity in patients undergoing carotid patch angioplasty?

BACKGROUND

This study was undertaken to determine whether the choice of material influences the early morbidity of patients undergoing carotid patch angioplasty.

METHODS

Before undergoing carotid endarterectomy, 190 patients were randomized to receive 207 patch closures with either Dacron (USCI Sauvage knitted velour) or saphenous vein harvested from the thigh.

RESULTS

One hundred seven Dacron and 100 vein patch angioplasties were performed. No significant difference was seen between the two groups in patient age, sex preoperative risk factors, or indication for operation (p > 0.25 for each variable). Among the patients undergoing Dacron patch angioplasty three strokes (two temporary and one permanent), seven episodes of bleeding requiring reoperation, and two neck wound infections requiring rehospitalization occurred. The final 32 patients with Dacron patch closures had their anticoagulation reversed and had no bleeding complications. Complications inpatients undergoing vein patch closure included one fatal perioperative stroke, two episodes of bleeding requiring reoperation including one patch rupture, and three groin infections requiring hospitalization. No significant difference was seen between the two groups in the rate of perioperative stroke (p = 0.62), episodes of bleeding (p = 0.17), or infection (p = >0.67).

CONCLUSIONS

Carotid patch angioplasty can be performed with an acceptably low complication rate with either Dacron or vein, and the choice of patch material does not clinically affect patient morbidity. However, reversal of anticoagulation is recommended to minimize bleeding complications in patients undergoing Dacron patch angioplasty.

Carotid endarterectomy: the gold standard

Carotid endarterectomy has been firmly established as the gold standard of therapy for symptomatic and asymptomatic patients with severe carotid stenosis, provided surgical complication rates are within prescribed limits. The procedure-related risk of stroke/death should be < 3% in asymptomatic patients and < 6% in symptomatic patients. New investigational therapies such as balloon angioplasty and stenting for carotid stenosis should be evaluated against the same standard.

Guidelines for carotid endarterectomy. A multidisciplinary consensus statement from the Ad Hoc Committee, American Heart Association

BACKGROUND AND PURPOSE

Indications for carotid endarterectomy have engendered considerable debate among experts and have resulted in publication of retrospective reviews, natural history studies, audits of community practice, position papers, expert opinion statements, and finally prospective randomized trials. The American Heart Association assembled a group of experts in a multidisciplinary consensus conference to develop this statement.

METHODS

A conference was held July 16-18, 1993, in Park City, Utah, that included recognized experts in neurology, neurosurgery, vascular surgery, and healthcare planning. A program of critical topics was developed, and each expert presented a talk and provided the chairman with a summary statement. From these summary statements a document was developed and edited onsite to achieve consensus before final revision.

RESULTS

The first section of this document reviews the natural history, methods of patient evaluation, options for medical management, results of surgical management, data from position statements, and results to date of prospective randomized trials for symptomatic and asymptomatic patients with carotid artery disease. The second section divides 96 potential indications for carotid endarterectomy, based on surgical risk, into four categories: (1) Proven: This is the strongest indication for carotid endarterectomy; data are supported by results of prospective contemporary randomized trials. (2) Acceptable but not proven: a good indication for operation; supported by promising but not scientifically certain data. (3) Uncertain: Data are insufficient to define the risk/benefit ratio. (4) Proven inappropriate: Current data are adequate to show that the risk of surgery outweighs any benefit.

CONCLUSIONS

Indications for carotid endarterectomy in symptomatic good-risk patients with a surgeon whose surgical morbidity and mortality rate is less than 6% are as follows. (1) Proven: one or more TIAs in the past 6 months and carotid stenosis > or = 70% or mild stroke within 6 months and a carotid stenosis > or = 70%; (2) acceptable but not proven: TIAs within the past 6 months and a stenosis 50% to 69%, progressive stroke and a stenosis > or = 70%, mild or moderate stroke in the past 6 months and a stenosis 50% to 69%, or carotid endarterectomy ipsilateral to TIAs and a stenosis > or = 70% combined with required coronary artery bypass grafting; (3) uncertain: TIAs with a stenosis < 50%, mild stroke and stenosis < 50%, TIAs with a stenosis < 70% combined with coronary artery bypass grafting, or symptomatic, acute carotid thrombosis; (4) proven inappropriate: moderate stroke with stenosis < 50%, not on aspirin; single TIA, < 50% stenosis, not on aspirin; high-risk patient with multiple TIAs, not on aspirin, stenosis < 50%; high-risk patient, mild or moderate stroke, stenosis < 50%, not on aspirin; global ischemic symptoms with stenosis < 50%; acute dissection, asymptomatic on heparin. Indications for carotid endarterectomy in asymptomatic good-risk patients performed by a surgeon whose surgical morbidity and mortality rate is less than 3% are as follows. (1) Proven: none. As this statement went to press, the National Institute of Neurological Disorders and Stroke issued a clinical advisory stating that the Institute has halted the Asymptomatic Carotid Atherosclerosis Study (ACAS) because of a clear benefit in favor of surgery for patients with carotid stenosis > or = 60% as measured by diameter reduction. When the ACAS report is published, this indication will be recategorized as proven. (2) acceptable but not proven: stenosis > 75% by linear diameter; (3) uncertain: stenosis > 75% in a high-risk patient/surgeon (surgical morbidity and mortality rate > 3%), combined carotid/coronary operations, or ulcerative lesions without hemodynamically significant stenosis; (4) proven inappropriate: operations with a combined stroke morbidity and mortality > 5%.

Surgical therapy for coronary artery disease among patients with combined coronary artery and peripheral vascular disease

BACKGROUND

Among patients with combined coronary artery and peripheral vascular disease, long-term benefits of surgical therapy compared with medical therapy for coronary artery disease are unknown.

METHODS AND RESULTS

Using prospectively collected data from the Coronary Artery Surgery Study registry, we performed a retrospective cohort analysis of 1834 patients (mean age, 56 years; 20% women) with both coronary artery and peripheral vascular disease and evaluated their long-term outcomes. Of these patients, 986 received (nonrandomly) coronary artery bypass graft surgery, and 848 were treated medically. Perioperative mortality was 4.2% (2.9% in the absence of peripheral vascular disease; P = .02). In a mean follow-up period of 10.4 years, 1100 deaths occurred (80% due to cardiovascular causes). For the surgical group, 4-, 8-, 12-, and 16-year estimated probabilities of survival were 88%, 72%, 55%, and 41%, respectively, and 73%, 57%, 44%, and 34%, respectively, for the medical group (P < .0001). Multivariate analysis demonstrated that type of therapy was independently associated with survival (P = .0001; chi 2 = 15.34). Subgroup analysis suggested that benefits of surgical treatment on survival were limited to patients with three-vessel coronary artery disease and were inversely related to ejection fraction. Survival free of death or myocardial infarction was also significantly better among the surgical group. Type of therapy was significantly associated with occurrence of late events (P = .01; chi 2 = 6.55). Subgroup analysis again demonstrated that beneficial effects of surgery were limited to patients with three-vessel coronary artery disease and were inversely related to ejection fraction.

CONCLUSIONS

Surgical treatment provides long-term benefit for certain subgroups of patients with combined coronary artery and peripheral arterial vascular disease.

Guidelines for carotid endarterectomy. A multidisciplinary consensus statement from the ad hoc Committee, American Heart Association

BACKGROUND AND PURPOSE

Indications for carotid endarterectomy have engendered considerable debate among experts and have resulted in publication of retrospective reviews, natural history studies, audits of community practice, position papers, expert opinion statements, and finally prospective randomized trials. The American Heart Association assembled a group of experts in a multidisciplinary consensus conference to develop this statement.

METHODS

A conference was held July 16-18, 1993, in Park City, Utah, that included recognized experts in neurology, neurosurgery, vascular surgery, and healthcare planning. A program of critical topics was developed, and each expert presented a talk and provided the chairman with a summary statement. From these summary statements a document was developed and edited onsite to achieve consensus before final revision.

RESULTS

The first section of this document reviews the natural history, methods of patient evaluation, options for medical management, results of surgical management, data from position statements, and results to date of prospective randomized trials for symptomatic and asymptomatic patients with carotid artery disease. The second section divides 96 potential indications for carotid endarterectomy, based on surgical risk, into four categories: (1) Proven: This is the strongest indication for carotid endarterectomy; data are supported by results of prospective contemporary randomized trials. (2) Acceptable but not proven: a good indication for operation; supported by promising but not scientifically certain data. (3) Uncertain: Data are insufficient to define the risk/benefit ratio. (4) Proven inappropriate: Current data are adequate to show that the risk of surgery outweighs any benefit.

CONCLUSIONS

Indications for carotid endarterectomy in symptomatic good-risk patients with a surgeon whose surgical morbidity and mortality rate is less than 6% are as follows. (1) Proven: one or more TIAs in the past 6 months and carotid stenosis > or = 70% or mild stroke within 6 months and a carotid stenosis > or = 70%; (2) acceptable but not proven: TIAs within the past 6 months and a stenosis 50% to 69%, progressive stroke and a stenosis > or = 70%, mild or moderate stroke in the past 6 months and a stenosis 50% to 69%, or carotid endarterectomy ipsilateral to TIAs and a stenosis > or = 70% combined with required coronary artery bypass grafting; (3) uncertain: TIAs with a stenosis < 50%, mild stroke and stenosis < 50%, TIAs with a stenosis < 70% combined with coronary artery bypass grafting, or symptomatic, acute carotid thrombosis; (4) proven inappropriate: moderate stroke with stenosis < 50%, not on aspirin; single TIA, < 50% stenosis, not on aspirin; high-risk patient with multiple TIAs, not on aspirin, stenosis < 50%; high-risk patient, mild or moderate stroke, stenosis < 50%, not on aspirin; global ischemic symptoms with stenosis < 50%; acute dissection, asymptomatic on heparin. Indications for carotid endarterectomy in asymptomatic good-risk patients performed by a surgeon whose surgical morbidity and mortality rate is less than 3% are as follows. (1) Proven: none. (As this statement went to press, the National Institute of Neurological Disorders and Stroke issued a clinical advisory stating that the Institute has halted the Asymptomatic Carotid Atherosclerosis Study (ACAS) because of a clear benefit in favor of surgery for patients with carotid stenosis > or = 60% as measured by diameter reduction. When the ACAS report is published, this indication will be recategorized as proven. (2) acceptable but not proven: stenosis > 75% by linear diameter; (3) uncertain; stenosis > 75% in a high-risk patient/surgeon (surgical morbidity and mortality rate > 3%), combined carotid/coronary operations, or ulcerative lesions without hemodynamically significant stenosis; (4) proven inappropriate: operations with a combined stroke morbidity and mortality > 5%.

Surgical management in patients with coexistent coronary and cerebrovascular disease. Long-term results

Between January 1980 and December 1992, 3% (210/6,862) of our patients undergoing myocardial revascularization (CABG) had high grade (> 80%) internal carotid stenosis (CS). One hundred seventy-five of these patients with complete follow up for a minimum of 18 months were studied. Bilateral internal CS was present in 60%, and 75% had other vascular lesions, mainly as peripheral vascular disease (PVD) of the lower limb (50.8%). All patients underwent CAE (carotid endarterectomy) followed by CABG under the same anesthesia. Peripheral vascular lesions, contralateral internal CS and recurrent (n = 43) and progressive vascular lesions (n = 50), were subsequently treated as staged procedures. Hospital mortality was 3.42%. By univariate analysis significant predictors of late mortality were congestive heart failure, COPD, PVD, postoperative myocardial infarction, postoperative stroke, and ischemic cardiomyopathy. Only the latter two were also significant by multivariate analysis. At 12 years, actuarial survival in the presence of these risk factors were 46%, 49%, 22%, 37%, 53%, and 27% respectively. All are significantly lower as compared with the corresponding subsets of patients with the risk factor absent. At 12 years, actuarial survival for the entire series was 65%. Cumulative incidence of postoperative strokes was higher in patients with bilateral internal CS than in patients with unilateral internal CS (p < 0.07) and in patients with neurologic symptoms than asymptomatic patients. At 12 years, actuarial freedom from all cardiac related events, postoperative stroke, and symptomatic PVD were 49%, 82%, and 76% respectively. After successful revascularization these patients should be carefully followed for recurrent and progressive vascular lesions.

Optimal outcome for "high-risk" carotid endarterectomy

While carotid endarterectomy (CEA) can often be accomplished with a very low stroke risk, certain scenarios--prior ipsilateral stroke, contralateral carotid occlusion, or acute cerebral ischemia--have been associated with neurologic morbidity and mortality rates exceeding 10%. The routine use of temporary intraluminal carotid shunts has been thought to be obligatory in such patients, notwithstanding the fact that these devices are obtrusive and may be associated with an increased risk of perioperative stroke. Among 175 patients undergoing CEA, 68 could be classified as "high-risk" (contralateral carotid occlusion, n = 24; prior ipsilateral stroke, n = 28; acute cerebral ischemia, n = 16). CEA was performed under regional or local anesthetic block in all 68 patients. Sixty-six patients (97%), including 22 of 24 (92%) with contralateral carotid occlusion, underwent CEA (carotid occlusion times averaging 22 minutes [range: 12 to 42 minutes]) without insertion of a carotid shunt. Two patients (2.9%) with contralateral carotid occlusion lost consciousness 7 and 10 minutes after carotid clamping, but regained neurologic normalcy after shunt insertion. A single patient (1.5%) experienced a fatal stroke due to heparin-induced "white clot" syndrome. Rates of shunt insertion and of perioperative stroke did not differ from those in 107 "low-risk" CEA patients. Cerebral collateral circulation is well developed even in compromised CEA patients. The necessity for temporary carotid shunts may be reduced by the use of "awake" anesthesia in such cases. Carotid shunting may be no more necessary, and operative outcome no less favorable, in "high-risk" than in uncomplicated CEA patients.

Surgical treatment of recurrent carotid artery stenosis

Ninety-two surgical procedures were performed in 82 patients for recurrent carotid artery stenosis. The etiology was recurrent atherosclerosis in 45 cases, myointimal hyperplasia in 20, organized thrombus without a significant underlying plaque in 20, and scarring along the proximal arteriotomy site in seven. The operations included a repeat endarterectomy in 66 cases and reconstruction with an interposition graft in 22. All five major neurological complications occurred in symptomatic patients, and included three instances of intraoperative embolization during exposure of the carotid artery. The majority of neurological complications occurred in symptomatic patients who had intraluminal thrombus confirmed at surgery. There were four perioperative deaths, due to cerebral hemorrhage in two patients and myocardial infarction in two. In the patients whose original surgery was performed at the Mayo Clinic, the risk of recurrent carotid artery stenosis was 3.1% with a primary closure compared to 1.6% when a patch graft was used. These results indicate that surgery for recurrent carotid artery stenosis is technically more difficult and carries a significantly higher risk than surgery for primary disease. The difficulty is due to the friable recurrent plaque associated with intraluminal thrombus, which increases the risk of embolization during carotid artery exposure. In the majority of patients with recurrent atherosclerosis, a repeat endarterectomy can be achieved. However, in some patients, there is scarring without a definite plane of cleavage between the recurrent disease and the underlying media, making an endarterectomy difficult. In these cases, excision of the diseased segment and reconstruction with an interposition graft is the best treatment. The findings presented here also suggest that closure of the original arteriotomy with a patch graft decreases the risk of recurrent carotid artery stenosis.

The cause of perioperative stroke after carotid endarterectomy

PURPOSE

The purpose of this study was to examine the cause of perioperative stroke after carotid endarterectomy.

METHODS

The records of 2365 patients undergoing 3062 carotid endarterectomies from 1965 through 1991 were reviewed. Sixty-six (2.2%) operations were associated with a perioperative stroke. The mechanism of stroke was determined in 63 of 66 cases. Patient risk factors and surgeon-dependent factors were analyzed.

RESULTS

More than 20 different mechanisms of perioperative stroke were identified, but most could be grouped into broad categories of ischemia during carotid artery clamping (n = 10), postoperative thrombosis and embolism (n = 25), intracerebral hemorrhage (n = 12), strokes from other mechanisms associated with the surgery (n = 8), and stroke unrelated to the reconstructed artery (n = 8). Dividing the operative experience approximately into thirds, during the years 1965 to 1979, 1980 to 1985, and 1986 to 1991 the perioperative stroke rates were 2.7%, 2.2%, and 1.5%, respectively. This, in part, is associated with a better selection of patients (more symptom free, fewer with neurologic deficits). There has been a notable decrease in perioperative stroke caused by ischemia during clamping and intracerebral hemorrhage, but postoperative thrombosis and embolism remain the major cause of neurologic complications.

CONCLUSIONS

Although patient selection seems to play a role, most perioperative strokes were due to technical errors made during carotid endarterectomy or reconstruction and were preventable.

Long-term follow-up for recurrent stenosis: a prospective randomized study of expanded polytetrafluoroethylene patch angioplasty versus primary closure after carotid endarterectomy

PURPOSE

To determine the effect of primary closure (PC) versus expanded polytetrafluoroethylene patch graft angioplasty (PGA) on the incidence of recurrent stenosis (> 50% lumen diameter narrowing) after carotid endarterectomy (CEA), 87 patients undergoing 100 consecutive CEA were prospectively randomized into two groups.

METHODS

Forty-four patients underwent 51 PC, and 43 patients underwent 49 PGA. All patients were evaluated after operation by duplex scanning at 1.5, 12, 24, and 36 months. There were no significant differences in the demographic characteristics or operative indications for CEA between the two patient groups. Complete follow-up was achieved in 86% (75/87) of the patients during the 36-month surveillance period.

RESULTS

The perioperative permanent neurologic morbidity in the PC and PGA groups was noted to be 4% and 2%, respectively (PC = 2/51 vs PGA = 1/49, p = 0.58). Three additional reversible cerebral ischemic events occurred in the postoperative period (PC = 2/51 vs PGA = 1/49, p = 0.58). Other morbidity included immediate postoperative hemorrhage requiring reexploration (1/51) in the PC group and an infected expanded polytetrafluoroethylene patch requiring removal and replacement with autogenous vein (1/49). Long-term follow-up detected a single patient with significant bilateral restenoses of his primarily closed carotid arteries. None of the patients in the PGA group had restenoses (PC = 2/51 vs 0/49, p = 0.50). In addition, no postoperative dilation of the common or internal carotid arteries or perioperative death was observed.

CONCLUSIONS

In patients undergoing CEA, these data demonstrate no significant difference in the perioperative morbidity or mortality between PC and PGA. Use of the patch did not engender patients to patch rupture or aneurysmal degeneration as previously described with vein patch angioplasty procedures. This series supports effective use of either technique to achieve minimal rates of restenosis.

Screening cerebrovascular patients for silent myocardial ischemia with stress testing and ambulatory left ventricular function monitor

Patients with symptomatic cerebrovascular disease suffer a high mortality from myocardial ischemia, which may occur during rest or following the conclusion of exercise. In a pilot study, we screened 11 patients with transient cerebral ischemic attack or stroke for silent myocardial ischemia using bicycle ergometer stress testing with electrocardiographic (EKG) monitoring and ambulatory left ventricular function monitoring (VEST). Three of 11 patients had nondiagnostic exercise EKGs due to failure to achieve their target heart rates during exercise but had positive VEST tests during and after exercise. One patient was falsely positive. VEST may be useful in combination with stress EKG for the detection of silent myocardial ischemia in cerebrovascular patients, but further assessment of the sensitivity and specificity in this patient population needs to be accomplished.

Internal carotid artery surgery: ten-year results

The twofold purpose of this study was to compare the immediate results of surgery for lesions of the internal carotid artery in two series of patients operated on at 10-year intervals and to assess long-term results in the earliest series. Series I comprised 242 reconstructions in 220 patients (160 men and 60 women, mean age 64.4 years) performed between 1980 and 1982. Seventy patients (35%) were asymptomatic, 113 had monocular or hemispheric symptoms, and 30 had nonhemispheric symptoms. Contrast arteriograms revealed internal carotid artery stenosis of < 30% in 74 cases (30.6%), between 30% and 70% in 49 (20.2%), and > 70% in 119 (49.2%). Reconstruction was achieved by endarterectomy in 164 cases (67.8%), by vein graft in 75 cases (31%), and by other methods in 3 cases (1.2%). Postoperative mortality was 5% (11/110). Nonfatal postoperative stroke occurred in 1.8% (4/220) and transient ischemic attack in 0.5% (1 patient). All reconstructions were patent on postoperative control. The combined mortality/morbidity rate in patients in series II operated on between 1990 and 1991 was significantly lower, that is, 2.4% (4/170) vs. 6.8% (15/220) (p < 0.05). In series I, 11 patients (5%) were lost to follow-up and 124 were still alive at the beginning of the tenth postoperative year. Cumulative survival was 79 +/- 5.6% at 5 years and 60.9 +/- 6.7% at 10 years. The causes of late death were stroke in 7 cases, cardiovascular disease in 30 cases, cancer in 16 cases, and other causes in 20 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid endarterectomy for prevention of stroke

Carotid endarterectomy, a frequently performed operation, has been used as a strategy for preventing stroke in patients with carotid bifurcation disease. The safety and efficacy of the operation were recently challenged by a number of sources. Three major responses to this challenge were to retrospectively review the natural history of carotid bifurcation disease compared with the immediate and long-term results of carotid endarterectomy, to initiate 6 prospective randomized trials to determine the efficacy of carotid endarterectomy for a variety of indications, and to develop appropriateness initiatives and guidelines for using this surgical procedure by organizations concerned with health care policy. I review the current status of these 3 areas of endeavor. In those areas where studies are complete, carotid endarterectomy has been shown to be highly effective in reducing stroke risk. Risk reduction has ranged from 66% to 80% compared with medical management. Based on these sources and findings, I present a list of indications for the operation for surgeons who are able to do the operation safely and within the guidelines established by the Stroke Council of the American Heart Association.

Differences in carotid shunt flow rates and implications for cerebral blood flow

A wide variety of carotid shunts are available for use in extracranial carotid surgery. Since it is commonly assumed that when properly positioned all shunts are equal in ability to protect the brain from cerebral ischemia, the choice of shunt is usually based on handling characteristics. However, after an intraoperative stroke occurred in a patient, we compared shunt flow rates using a simple and reproducible method of measurement. A mock circuit was created using a saline-filled fluid reservoir connected to the particular shunt being tested via 1/2-inch tubing. Hydrostatic pressure across the shunt was varied by changing the height of the reservoir, and the flow was collected over 30-second intervals. Multiple flow rate measurements were performed for each shunt with pressure gradients varying from 25 to 150 cm H2O. The data show significant hemodynamic differences among commercially available carotid shunts. A pressure gradient of 75 cm H2O produced a 2.8-fold variation in the amount of fluid delivered by various shunts. Minimal cerebral blood flow requirements and the possibility of underperfusion require that the surgeon consider such data in choosing an appropriate carotid shunt.