Late patency of the carotid artery after endarterectomy

Role of Residual Defects Following Carotid Endarterectomy in the Occurrence of Cerebrovascular Symptoms

Carotid endarterectomy deals successfully with carotid atheromatous lesions, thus eliminating a potential source of cerebral emboli. At times, however, residual hemodynamic irregularities may occur as a result of technique imperfection or anatomic variations. These irregularities have been associated with a number of immediate and late postoperative complications, such as recurrent cerebrovascular symptoms and secondary episodes of stroke. For this reason, the detection of flow abnormalities or intimal defects in patients undergoing carotid endarterectomy and the achievement of normal intraoperative and postoperative hemodynamics are essential for the elimination of potentially life-threatening perioperative and late cerebrovascular events.

Recurrent Carotid Disease: Optimum Technique for Redo Surgery

Carotid restenosis has been a well-recognized, though not well-understood, long-term complication of carotid endarterectomy. Various factors contribute to recurrent stenosis, but the chief cause is technical faults during the primary procedure. Redo endarterectomy or graft reconstruction are the traditional and most effective procedures for treating symptomatic or high-grade (> 80%) asymptomatic restenotic lesions.

To reduce the potential for carotid restenosis, eversion endarterectomy is recommended as the technique of choice for de novo carotid disease treatment. Angioscopy is useful in detecting correctable technical errors that could predispose to restenosis.

Restenosis after carotid endarterectomy

Multiple randomised trials over the last decade for both symptomatic and asymptomatic carotid stenosis have proven the efficacy of carotid endarterectomy (CE) in reducing the risk of stroke. The long-term patency of the carotid artery after CE is an important factor in the success of the operation. The incidence of recurrent carotid stenosis (excluding residual lesions) ranges from 1 to 37% with only 0-8% of patients having restenosis-related symptoms (1). Generally, recurrent carotid stenosis is attributed to myointimal hyperplasia during the early postoperative period (within 3 years) or recurrent atherosclerosis thereafter. The management of recurrent carotid stenosis after CE remains a dilemma. It is generally accepted that operation for significant recurrent carotid stenosis is indicated for symptomatic patients, and several authors also recommend CE for >80% asymptomatic recurrent stenosis. Treatment of recurrent carotid stenosis involves repeat endarterectomy with patch angioplasty, although more recently endovascular techniques have been used.

Carotid revascularization for prevention of stroke: carotid endarterectomy and carotid artery stenting

Carotid endarterectomy (CEA) has been used for the past several decades in patients with carotid occlusive disease. Large randomized controlled trials have documented that CEA is a highly effective stroke preventive among patients with carotid stenosis and recent transient ischemic attack or cerebral infarction. In asymptomatic patients with carotid stenosis, clinical trial data suggest that the degree of stroke prevention from CEA is less than among symptomatic patients. However, otherwise healthy men and women with an asymptomatic carotid stenosis of 60% or greater have a lower risk of future cerebral infarction, including disabling cerebral infarction, if treated with CEA compared with those treated with medical management alone. More recently, carotid artery stenting has been performed Increasingly for patients with carotid occlusive disease. As technology has improved, procedural risks have declined and are approaching those reported for CEA. The benefits and durability of CEA compared with carotid artery stenting are still unclear and are being studied in ongoing randomized controlled trials.

Early postsurgical carotid restenosis: redo surgery versus angioplasty/stenting

PURPOSE

To compare the results of balloon angioplasty/stenting (BA/S) versus redo surgery in patients with early carotid restenosis.

METHODS

Sixty-one patients (35 women; mean age 69 years, range 46-82) with early restenosis (<24 months from the primary endarterectomy) in 63 carotid arteries were treated during a 5-year period; 41 patients (41 arteries) had redo surgery (group A) and 20 patients (22 arteries) had BA/S (group B). Patients were followed regularly with duplex ultrasound to detect >or=50% recurrent restenosis (RRS) after redo surgery or BA/S. Kaplan-Meier life-table analysis was used to estimate the stroke-free survival rates and freedom from >or=50% RRS.

RESULTS

The demographic and clinical characteristics were comparable for both groups, as were the perioperative stroke and death rates (2.4% and 0% for group A, respectively, versus 4.5% and 0% for group B, p=0.46). Group A had a 12% incidence of cranial nerve injury (all transient) versus 0% for group B (p=0.11); however, group B had a higher incidence of >or=50% RRS than group A (32% versus 0%, p=0.0003). The stroke-free survival rates for redo surgery at 6, 12, 24, 36, and 48 months were 100%, 100%, 100%, 100%, and 88% versus 95%, 95%, 84%, 84%, and 63% for BA/S (p=0.067). Redo surgery had a 100% freedom from >or=50% RRS at the same time intervals, while recurrent restenosis rates for the BA/S patients were 95%, 86%, 69%, 52%, and 52% (p<0.0001).

CONCLUSIONS

BA/S and redo surgery have comparable stroke and death rates in the treatment of early RCS; however, redo surgery is associated with cranial nerve injuries (transient), while stent patients have a higher incidence of recurrent lesions. These considerations should be kept in mind when selecting the appropriate treatment for patients with early postsurgical restenosis.

A prospective, randomized study of saphenous vein patching versus synthetic patching during carotid endarterectomy

OBJECTIVE

The objective of this study was the determination of whether the choice of either autogenous saphenous vein (ASV) or synthetic material for patch angioplasty significantly influences the results after carotid endarterectomy (CEA).

METHODS

With Institutional Review Board approval, 195 patients (145 men and 50 women; mean age, 69 years) who underwent 207 CEAs were prospectively randomized to arteriotomy closure with ASV or synthetic patches from July 1996 to January 2000. One hundred and one patients (52%) were randomized to the ASV cohort, and 94 (48%) were randomized to the synthetic cohort. Aside from a slight gender imbalance (70% versus 79% male in the ASV versus the synthetic group), there were no clinically important differences in baseline demographic variables, risk factors, or surgical indications between the ASV and synthetic groups.

RESULTS

With all 207 randomized procedures on an intent-to-treat basis, there were two early (<30 days) postoperative deaths (1%). There were three perioperative strokes in the ASV cohort (3.0%) and two in the synthetic cohort (2.1%; P =.99). Two of these early strokes occurred in a subset of nine patients who received neither patch material, all after randomization but before CEA. Two patients in each group had late strokes. The cumulative freedom from stroke rate at 1 year (ASV, 94%; synthetic, 95%) was virtually identical for both cohorts. With the 125 patients who had at least one postoperative duplex scan, the incidence rate of recurrent (>or=60%) carotid stenosis was 4.8% (three of 62) for the ASV group and 6.3% (four of 63) for the synthetic group (P =.99).

CONCLUSION

No significant differences in the stroke, mortality, or restenosis rates were shown between the ASV and the synthetic cohorts. While conceding the power limitations inherent in this study, we conclude that CEA may be safely performed with similar early results with ASV or synthetic patches.

Redo carotid endarterectomy versus primary carotid endarterectomy

BACKGROUND AND PURPOSE

Several authorities have recently advocated carotid stenting for recurrent carotid stenosis because of the perception that redo surgery has a higher complication rate than primary carotid endarterectomy (CEA). This study compares the early and late results of reoperations versus primary CEA.

METHODS

All reoperations for recurrent carotid stenosis performed during a recent 7-year period by a single vascular surgeon were compared with primary CEA. Because all redo CEAs were done with polytetrafluoroethylene (PTFE) or vein patch closure, we only analyzed those primary CEAs that used the same patch closures. A Kaplan-Meier life-table analysis was used to estimate stroke-free survival rates and freedom from >/=50% recurrent stenosis.

RESULTS

Of 547 primary CEAs, 265 had PTFE or saphenous vein patch closure, and 124 reoperations had PTFE or vein patch closure during the same period. Both groups had similar demographic characteristics. The indications for reoperation and primary CEA were symptomatic stenosis in 78% and 58% of cases and asymptomatic >/=80% stenosis in 22% and 42% of cases, respectively (P<0.001). The 30-day perioperative stroke and transient ischemic attack rates for reoperation and primary CEA were 4.8% versus 0.8% (P=0.015) and 4% versus 1.1%, respectively, with no perioperative deaths in either group. Cranial nerve injury was noted in 17% of reoperation patients versus 5.3% of primary CEA patients; however, most of these injuries were transient (P<0.001). Mean hospital stay was 1.8 days for reoperation versus 1.6 days for primary CEA. Cumulative rates of stroke-free survival and freedom from >/=50% recurrent stenosis for reoperation and primary CEA at 1, 3, and 5 years were 96%, 91%, and 82% and 98%, 96%, and 95% versus 94%, 92%, and 91% and 98%, 96%, and 96%, respectively (no significant differences).

CONCLUSIONS

Reoperation carries higher perioperative stroke and cranial nerve injury rates than primary CEA. However, reoperations are durable and have stroke-free survival rates that are similar to primary CEA. These considerations should be kept in mind when carotid stenting is recommended instead of reoperation.

Reoperation for recurrent carotid stenosis: early results and late outcome in 199 patients

PURPOSE

This study was undertaken to determine the safety and efficacy of reoperations for recurrent carotid stenosis (REDOCEA) at the Cleveland Clinic.

MATERIALS AND METHODS

From 1989 to 1999, 206 consecutive REDOCEAs were performed in 199 patients (131 men, 68 women) with a mean age of 68 years (median, 69 years; range, 47-86 years). A total of 119 procedures (57%) were performed for severe asymptomatic stenosis, 55 (27%) for hemispheric transient ischemic attacks or amaurosis fugax, 26 (13%) for prior stroke, and 6 (3%) for vertebrobasilar symptoms. Eleven REDOCEAs (5%) were combined with myocardial revascularization, and another 19 (9%) represented multiple carotid reoperations (17 second reoperations and 2 third reoperations). Three REDOCEAs (1%) were closed primarily, and nine (4%) required interposition grafts, whereas the remaining 194 (95%) were repaired with either vein patch angioplasty (139 [68%]) or synthetic patches (55 [27%]). Three patients (2%) were lost to follow-up, but late information was available for 196 patients (203 operations) at a mean interval of 4.3 years (median, 3.9 years; maximum, 10.2 years).

RESULTS

Considering all 206 procedures, there were 7 early (< 30 days) postoperative neurologic events (3.4%), including 6 perioperative strokes (2.9%) and 1 occipital hemorrhage (0.5%) on the 12th postoperative day. Seventeen additional neurologic events occurred during the late follow-up period, consisting of eight strokes (3.9%) and nine transient ischemic attacks (4.4 %). With the Kaplan-Meier method, the estimated 5-year freedom from stroke was 92% (95% CI, 88%-96%). There were two early postoperative deaths (1%), both from cardiac complications after REDOCEAs combined with myocardial revascularization procedures. With the Kaplan-Meier method, the estimated 5-year survival was 81% (range, 75%-88%). A univariate Cox regression model yielded the presence of coronary artery disease as the only variable that was significantly associated with survival (P =.024). The presence of pulmonary disease (P =.036), diabetes (P =.01), and advancing age (P =.006) was found to be significantly associated with stroke after REDOCEA. Causes of 53 late deaths were cardiovascular problems in 25 patients (47%), unknown in 14 (26%), renal failure in 4 (8%), stroke in 3 (6%), and miscellaneous in 7 (13%).

CONCLUSIONS

We conclude that REDOCEA may be safely performed in selected patients with recurrent carotid stenosis and that most of these patients enjoy long-term freedom from stroke.

Carotid recurrent stenosis and risk of ipsilateral stroke: a systematic review of the literature

BACKGROUND

The main goal of follow-up after carotid endarterectomy is to prevent new strokes caused by recurrent stenosis. To determine the most cost-effective follow-up schedule, it is necessary to know the incidence of recurrent stenosis and the risk of stroke it carries.

METHODS

A systematic review of the literature was performed using standard meta-analytical techniques.

RESULTS

Incidence of recurrent stenosis: The data were very heterogeneous. The risk of recurrent stenosis was 10% in the first year, 3% in the second, and 2% in the third. Long-term risk of recurrent stenosis is about 1% per year. Risk of stroke: The reported relative risks of stroke in patients with recurrent stenosis compared with patients without recurrent stenosis showed extreme heterogeneity and ranged from 10 to 0.10. The random effects summary estimator of relative risk was 1.88.

CONCLUSIONS

The data were very heterogeneous, and much better data are needed to arrive at truly reliable estimates of these important parameters of follow-up. It is clear, though, that the risk of recurrent stenosis is highest in the first few years after carotid endarterectomy and very low in later years. By use of general decision-analytic arguments, it can be argued that, given the test characteristics of carotid ultrasound, a small number of tests can be done in the first few years and that testing for restenosis should not be done after 4 years.

Edgar J. Poth Memorial/W.L. Gore and Associates, Inc. Lectureship. The clinical and pathological spectrum of recurrent carotid stenosis

BACKGROUND

Hemodynamically significant (> or =50%) carotid restenosis occurs in approximately 10% to 12% of individuals undergoing carotid endarterectomy. The underlying pathology is usually neointimal thickening within 3 years and recurrent atherosclerosis thereafter. Although a number of etiologic factors have been implicated in the development of restenosis, the etiology remains unclear and preventative measures relatively ineffective.

METHODS

A review of the English literature was undertaken to determine the incidence, clinical presentation, and pathologic features of carotid restenosis.

CONCLUSIONS

Carotid restenosis is the major factor limiting long-term patency after carotid endarterectomy. Although drug therapy has been shown to be effective in preventing restenosis in animal models, the results of clinical human trials have been disappointing. Delineation of the biochemical and molecular mechanisms contributing to the development of restenosis is essential if effective therapeutic interventions are to be developed.

Carotid endarterectomy in adults 50 years of age and younger: a retrospective comparative study

PURPOSE

Atherosclerotic carotid artery stenosis (CAS) is the most common cause of stroke in young adults. We retrospectively studied clinical characteristics of premature CAS and the safety and durability of carotid endarterectomy (CEA) in 56 patients 50 years of age or younger (mean, 46.4 years; 34 (60%) males; group I) who underwent primary CEA at the Cleveland Clinic between 1983 and 1993.

METHODS

The patients were identified from the Vascular Surgery Registry and were compared with 202 randomly selected patients 60 years of age and older (mean, 69.3 years; group II) who were frequency-matched by gender and the year of primary CEA. Carotid shunting was used routinely, and the arteriotomy was patched in the majority of cases. Patients were followed-up for mean of 47.2 months (group I) and 46.0 months (group II).

RESULTS

No significant differences were found in the indications for CEA (symptomatic CAS, 49% in group I vs 48% in group II) or the prevalence of diabetes, coronary diseases, and lower extremity arterial disease. Younger adults were more likely to have a history of smoking (93% vs 76%; p = 0.005), hypertension (71% vs 52%; p = 0.006), premature menopause (57% vs 18%; p < 0.001) and had lower levels of high-density lipoprotein cholesterol (p = 0.03). There were no in-hospital deaths. Perioperative strokes in the distribution of the operated artery occurred within 24 hours in one younger patient (1.8%) and in one older patient (0.5%). This was attributed to early carotid thrombosis in the young patient. Major late postoperative neurologic complications were documented in one young patient (1.8%) and six older patients (3%). Patients in group I were at significantly higher risk for recurrent carotid stenosis (risk ratio, 3.1; 95% confidence interval [CI], 1.3 to 7.3; p = 0.010); younger individuals remained at significantly higher risk for recurrent stenosis even after adjusting for smoking and hypertension (risk ratio, 3.7; 95% CI, 1.5 to 9.4; p = 0.006). By life-table analysis, younger adults tended to have a higher rate of late reoperations (p = 0.065).

CONCLUSIONS

CEA can be safely performed in young adults with premature CAS, although younger individuals appear to have higher rates of recurrent carotid stenosis compared with older counterparts.

Recurrent carotid disease: optimum technique for redo surgery

Carotid restenosis has been a well-recognized, though not well-understood, long-term complication of carotid endarterectomy. Various factors contribute to recurrent stenosis, but the chief cause is technical faults during the primary procedure. Redo endarterectomy or graft reconstruction are the traditional and most effective procedures for treating symptomatic or high-grade (> 80%) asymptomatic restenotic lesions. To reduce the potential for carotid restenosis, eversion endarterectomy is recommended as the technique of choice for de novo carotid disease treatment. Angioscopy is useful in detecting correctable technical errors that could predispose to restenosis.

Safety and durability of redo carotid endarterectomy for recurrent carotid artery stenosis

We retrospectively reviewed the records of patients who underwent redo carotid endarterectomies during a 5-year period. Patients were followed by duplex ultrasound to assess late patency of the carotid artery. Reoperations for recurrent carotid stenosis were performed in 46 of 973 patients who had carotid endarterectomies (5%). Indications for surgery were hemispheric transient ischemic attacks (TIA) in 33 (72%) and asymptomatic greater than 80% stenosis in 13 (28%). Pathologic findings revealed that the cause of recurrence was myointimal hyperplasia in 11 patients (24%), with a mean recurrence interval of 12.8 postoperative months, and atherosclerosis in 35 (76%), with a mean recurrence interval of 84 postoperative months (P = 0.0002). Redo endarterectomy with patch angioplasty was used for reconstruction in 32 cases (70%), patch angioplasty alone in 11 (24%), and endarterectomy with primary closure in 3. There were 3 perioperative strokes (7%). Late follow-up (mean 30.9 months) revealed no strokes and 1 TIA. Of 40 patients, 34 (85%) were alive and stroke free. Although six late deaths occurred, none were stroke related. One patient (2%) had late significant second recurrent carotid stenosis. Redo carotid endarterectomy for symptomatic patients and asymptomatic high-grade stenosis is safe and durable.

Does carotid eversion endarterectomy and reimplantation reduce the risk of restenosis?

Two hundred twelve eversion endarterectomies of the internal carotid artery and reimplantation in the common carotid artery were performed between January 1985 and July 1990. A total of 206 patients with stenosis of 75% or more and with redundancy and tortuosity of the internal carotid artery underwent this procedure. Cumulative mortality and neurologic morbidity were 2.4%. Forty patients died during the course of follow-up, seven of neurologic causes (17.1%). Duplex scans of 107 operated carotid arteries were obtained an average of 27.1 months after surgery. Restenosis of > 50% was encountered in three patients (1.9%), two asymptomatic patients (1.3%) with > 75% restenosis and one symptomatic patient with occlusion (0.6%). These results contrast with a 13.5% rate of restenoses > 50% (including 5.9% of restenoses > 75% and 1.7% occlusions) observed after 156 consecutive endarterectomies performed and closed by direct suture by the same surgical team in 1987 at a mean follow-up of 44 months. We believe that this technique can be used more often because the the operative and long-term risks are not any greater than those of the other methods of carotid revascularization. Eversion endarterectomy associated with reimplantation is especially indicated when the internal carotid artery is elongated, is < 4 mm wide, and occurs in women.

Physical properties and testing methods for PTFE cardiovascular patches

Patching after endarterectomy, especially carotid artery surgery, is a common procedure to repair and close the surgical site. Both synthetic and natural materials can be used, but saphenous vein is preferred due to its greater long-term patency. In situations where it is not possible to use the saphenous vein, both Dacron and expanded polytetrafluoroethylene (ePTFE) patches have been used successfully. Expanded PTFE patches are readily available, soft and pliable, have excellent biocompatibility and do not require preclotting prior to implantation. Comparison of two types of ePTFE patches versus natural vessel show that they have more than adequate properties for their intended use.