- Email: [email protected]
Are Octogenarians at High Risk for Carotid Endarterectomy?
Are Octogenarians at High Risk for Carotid Endarterectomy? Amy K Bremner, MD, Steven G Katz, MD, FACS Several prospective randomized trials have proved carotid endarterectomy to be safe and effective for both symptomatic and asymptomatic patients younger than 80 years of age. Recently, carotid artery stenting (CAS) has been approved for use in selected high-risk patients. It has been proposed that being an octogenarian places patients in this high-risk category. STUDY DESIGN: All patients between the ages of 80 to 89 years undergoing carotid endarterectomy during a 12-year period were included in the study. Information included indications for carotid endarterectomy, associated risk factors, length of stay, and hospital course. Perioperative morbidity and mortality, including neurologic events and myocardial infarction, were recorded. RESULTS: A total of 103 carotid endarterectomies were performed in 95 octogenarians. Procedures were performed on 59 men and 36 women. Indications for operation included symptomatic carotid stenosis in 44 patients (43%) and asymptomatic carotid stenosis in 59 (57%). Associated risk factors included diabetes mellitus (17%), hypertension (76%), coronary artery disease (28%), hyperlipidemia (39%), and history of smoking (42%). There were 4 perioperative neurologic complications, which included 1 transient ischemic attack (0.97%), 2 minor strokes (1.94%), and 1 major stroke (0.97%). There were no deaths. CONCLUSIONS: Combined end points for adverse events are acceptable in the octogenarian. Carotid endarterectomy remains the gold standard for treatment of extracranial carotid disease in all age groups. Age alone should not place patients in the high-risk category for carotid endarterectomy. (J Am Coll Surg 2008;207:549–553. © 2008 by the American College of Surgeons) BACKGROUND:
In 1951, Fisher first postulated the link between extracranial carotid disease and stroke.1 Within the next few years, carotid resection by Eastcott and colleagues had been successfully performed to treat symptomatic carotid stenosis.2 During the ensuing 30 years, carotid endarterectomy became the most frequently performed vascular operation in the US, although its efficacy was anecdotal. In the early 1990s, several multiinstitutional prospective and randomized studies confirmed its efficacy in preventing stroke in both symptomatic and asymptomatic patients younger than 80 years of age.3,4 The number of octogenarians is expected to rapidly increase during the next several decades. This, coupled with the increasing likelihood of stroke and carotid bifurcation arteriosclerosis seen in this age group, makes proper treatment selection extremely important. Unfortunately, octo-
genarians were excluded from participation in the prospective and randomized studies that demonstrated the efficacy of carotid endarterectomy in preventing stroke in selected patients. Because of the perception that this age group is at increased risk from carotid endarterectomy, alternative treatment options, such as carotid artery stenting (CAS), have been suggested as a lower-risk alternative. Many of the trials evaluating CAS have used age older than 80 years as one of the high-risk criteria allowing entry into the studies. In fact, the Centers for Medicare and Medicaid Services use advanced age as justification for reimbursement for CAS. It is the purpose of this study to examine the morbidity of patients older than age 80 undergoing carotid endarterectomy in a single institution and determine if octogenarians are truly at high risk for carotid endarterectomy.
METHODS Records of all patients undergoing elective primary endarterectomy during a 12-year period were reviewed. Health Insurance Portability and Accountability Act⫺compliant, deidentified patient information was collected after IRB approval was obtained. Operative outcomes were determined by close review of the medical records, including outpatient visits. Routine neurologic examination was per-
Disclosure Information: Nothing to disclose. Received March 10, 2008; Revised May 5, 2008; Accepted May 6, 2008. From the Division of Vascular Surgery, University of Southern California, Keck School of Medicine, Los Angeles, CA (Katz) and Huntington Hospital, Pasadena, CA (Bremner). Correspondence address: Steven G Katz, MD, Office of Medical Education, Huntington Hospital, 100 W California Ave, Pasadena, CA 91105. email: [email protected]
© 2008 by the American College of Surgeons Published by Elsevier Inc.
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ISSN 1072-7515/08/$34.00 doi:10.1016/j.jamcollsurg.2008.05.002
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J Am Coll Surg
Table 1. Preoperative Risk Factors Abbreviations and Acronyms
Risk factors
n
%
CAPTURE ⫽ Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Unanticipated or Rare Results CAS ⫽ carotid artery stenting CREST ⫽ Carotid Revascularization Endarterectomy Versus Stent Trial
Hypertension Hyperlipidemia Coronary artery disease Diabetes mellitus Smoking
76 38 28 17 42
80.0 40.0 29.5 17.9 44.2
formed by members of the vascular surgery service within 24 hours of carotid endarterectomy and again at 1 and 6 weeks after operation, and neurologic consultation was obtained when any deficit was noted. Duplex ultrasonography scans were obtained in all patients before operation, and cerebral arteriography was used to confirm results in equivocal patients. Symptomatic patients were operated on when the duplex scan revealed a stenosis of ⱖ 70%, and asymptomatic patients were operated on when a stenosis of 80% to 99% was detected. Duplex scan criteria for predicting a 70% stenosis included a peak systolic velocity ⱖ 230 cm/s combined with an internal carotid/common carotid peak systolic velocity ratio of at least 4. If, in addition to these findings, an end diastolic velocity was discovered, an 80% to 99% stenosis was diagnosed. Carotid endarterectomy was offered to all but a small number of patients with comorbidities of such severity that they were believed to substantially limit life expectancy. Such conditions included dialysis-dependent renal failure, class IV heart failure and angina, uncontrolled malignancy, oxygen-dependent respiratory failure, and severe neurologic impairment. Individual patients were used as data points in calculating demographics and risk factors, and each operation was considered separately in outcomes analysis. Carotid endarterectomies were performed under general anesthesia with continuous intraarterial pressure monitoring. All operations were performed by two surgeons who held certificates of special qualifications in vascular surgery from the American Board of Surgery. Cefazolin sodium was administered immediately before operation and continued for 24 hours postoperatively. Infusions of dextran 40 were begun on induction of anesthesia and continued for 24 hours. All patients were systemically anticoagulated with 5,000 U heparin before arterial clamping. Indwelling shunts were used in all patients, and all arteriotomies were closed using a Dacron patch (Boston Scientific). Protamine sulfate was used to reverse heparin anticoagulation at the conclusion of operation. Administration of 325 mg aspirin was begun 24 hours after operation and continued indefinitely. After operations, all patients were monitored in the postanesthetic recovery unit for 6 hours and transferred to a monitored bed on the surgical floor if hemodynamically
n ⫽ 95.
stable. Perioperative hypertension was controlled with topical nitrates and calcium channel blockers, and parenteral medications were used only if these measures failed to control blood pressure. Perioperative -blockade was used at the discretion of the operating surgeon and attending anesthesiologist. Patient demographics, preoperative risk factors, and indication for operation were recorded. Study outcome measures included perioperative (30-day) death, stroke, myocardial infarction, length of stay, cranial nerve injury, and hematoma requiring reoperation. Neurologic deficits lasting 24 hours or less were considered to be transient ischemic attacks. Those deficits lasting longer than 24 hours that resolved completely within 30 days were considered to be minor strokes, and all others were categorized as major strokes. Myocardial infarction was diagnosed when patients with postoperative chest pain, arrhythmia, or hemodynamic instability were found to have a creatine kinase level at least two times the normal limit with a positive MB fraction. Patients were followed for a minimum of 30 days postoperatively.
RESULTS Between January 1, 1995, and December 31, 2006, 103 carotid endarterectomies were performed in 95 patients 80 years of age or older. This represents 15.3% of endarterectomies performed during this time period. Fifty-nine patients were male and 36 were female. Their ages ranged from 80 to 94 years, with a mean of 83.7 years. Patient risk factors are listed in Table 1. Indication for operation included asymptomatic carotid stenosis in 57.3% of patients, earlier stroke with good recovery in 21.3%, transient hemispheric ischemia in 18.4%, and nonhemispheric symptoms in 2.9%. Median length of stay was 2 days (range 1 to 32 days). Outcome measures are summarized in Table 2. The patient experiencing the transient ischemic attack experienced a transient worsening of a preexisting aphasia, which returned to baseline within 12 hours. The two patients who had minor strokes experienced a mild contralateral upper extremity paresis, which resolved completely on postoperative days 2 and 3, respectively. The single major deficit
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Table 2. Perioperative Outcome Measures Outcome
n
%
Transient ischemic attack Minor stroke Major stroke Myocardial infarction Cranial nerve injury Hematoma
1 2 1 3 3 2
0.97 1.94 0.97 2.91 2.91 1.94
n ⫽ 103.
occurred in a patient who had suffered a stroke before the operation and had made a good recovery. On the first postoperative day, a dense hemiparesis developed, and the patient was found to have an intracranial hemorrhage thought to be secondary to a reperfusion injury. His deficits did not resolve, and he required placement in a skilled nursing facility. Two of the three patients suffering a myocardial infarction had known preexisting coronary artery disease. One had previous coronary artery bypass operation and the second had experienced a myocardial infarction 3 years before operation. The third patient had only moderate hypertension as a risk factor. Transient paresis of the marginal mandibular nerve developed in 3 patients and was resolved within 90 days. No other cranial nerve injuries were noted. An additional two patients required reexploration for evacuation of a hematoma. One patient was found to have an expanding hematoma in the recovery room and was immediately reexplored. The second patient had been discharged home on warfarin sodium for atrial fibrillation and returned 3 days after discharge with a hematoma requiring evacuation. There were no deaths within 30 days of operation. Combined stroke and death rate was 2.91%.
DISCUSSION Approximately 700,000 new and recurrent strokes occur in the US annually, and it is estimated that 10% to 20% of these are related to carotid artery disease.5,6 In the last 30 years, the number of patients older than age 85 has increased 3-fold, and the remainder of the population has increased by only 50%. It has been estimated that by the year 2030, the number of octogenarians in the US will have increased to 70,000,000.7 Because the incidence of stroke increases with age, it can be inferred that stroke-related disability will consume a very substantial part of the healthcare budget. It is crucial to identify strategies that can potentially limit the devastating consequences of ischemic stroke. Much of the confusion surrounding the risk and benefit of carotid endarterectomy in the elderly results from their exclusion from prospective and randomized studies that
Octogenarians and Carotid Endarterectomy
551
proved the efficacy of carotid endarterectomy in both symptomatic and asymptomatic patients. The reason for their omission was most likely several-fold. A population study performed by Fisher and colleagues in 1989, suggested that patients older than 80 years of age had a 4-fold increase in mortality after carotid endarterectomy, and other studies seemed to confirm this finding.8-11 More recent studies have shown a decline in perioperative morbidity and mortality that appears to extend to octogenarians, suggesting that their risk is not prohibitive.7,12-14 At the time of initiation of the North American Symptomatic Carotid Endarterectomy Trial and Asymptomatic Carotid Atherosclerosis Study, there was a concern that octogenarians would not live long enough to benefit from endarterectomy. For Caucasian men reaching age 80, the life expectancy is 7.2 years and for women it is 9.1 years.15,16 We acknowledge that these statistics might not totally represent life expectancy in 80-year-olds with systemic arteriosclerosis. Because both symptomatic and asymptomatic patients gain benefit from carotid endarterectomy after 3 years, it would appear that octogenarians survive long enough to achieve a decrease in stroke morbidity from operative intervention. Although our study only focuses on the safety of endarterectomy, others have demonstrated its efficacy in those older than 80 years of age. In fact, 2 studies have shown that, on average, 80% of octogenarians survive at least 4 years after endarterectomy and that the vast majority are stroke free at 5 to 10 years.12,17 Recent studies have questioned routine categorization of those older than 80 years of age as being at high risk for carotid endarterectomy. Although some authors have suggested that octogenarians are at a higher risk for complications after endarterectomy, a number of others disagree. A recently published pooled analysis of ⬎ 2,500 patients reported a combined stroke mortality of 3.45% after carotid endarterectomy in octogenarians.13 Several articles have determined that there exists no substantial increase in combined stroke and death end points after endarterectomy when patients older than 80 are compared with a younger cohort.12,13,18 Results in our series tend to bear this out. Our overall combined stroke and death rate of 2.91% (4.65% in symptomatic and 1.75% in asymptomatic patients) fall well within the guidelines established by the Stroke Council of the American Heart Association.16,19-21 These results compare favorably with the 2.2% stroke and death rate reported in our previous publications that included a younger cohort of patients.22,23 It is also important to note that only 1 patient (0.97%) experienced a major stroke with a resultant permanent neurologic deficit. In contrast, a study of octogenarians with carotid stenosis who did not undergo intervention had a 16% rate of cerebral infarction,
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and 50% of this group required nursing home care and remained nonambulatory during longterm followup.24 This underscores the importance of offering carotid endarterectomy to patients older than 80 years of age who have a substantial carotid stenosis. Introduction of CAS has created controversy about its role in the treatment of patients with extracranial cerebrovascular disease. In experienced hands, CAS can be performed with a technical success rate of ⬎ 97% and a stroke rate of ⱕ 5% when performed in the general population of patients with substantial carotid stenosis.25,26 Advocates of CAS have championed its use in high-risk patients, defined as those excluded from the North American Symptomatic Carotid Endarterectomy Trial and Asymptomatic Carotid Atherosclerosis Study, and octogenarians constitute a large segment of this population. Although results of recent studies have demonstrated that the results of carotid endarterectomy do not differ substantially between patients aged 80 years and older and their younger counterparts, the same cannot be said for CAS. In the Carotid ACCULINK/ ACCUNET Post Approval Trial to Uncover Unanticipated or Rare Results (CAPTURE), the overall 30-day stroke, myocardial infarction, and death rate for patients older than 80 years of age was 7.7%, and it was 4.3% for younger patients. This difference was statistically significant. When results of those who were asymptomatic were separately analyzed (90% of patients), this difference persisted.27 In the lead-in phase of the Carotid Revascularization Endarterectomy Versus Stent Trial (CREST), octogenarians undergoing CAS performed by experienced interventionalists had a 30-day stroke and death rate of 12.1%, which is considerably higher than similar results reported for carotid endarterectomy in this and other studies.28 A study from the University of Pittsburgh reported a 30-day rate of stroke, death, and myocardial infarction of 9.2% in octogenarians and 3.4% in younger patients after CAS, a result that was statistically significant.29 It is especially interesting to note that 1 of the groups most experienced in carotid intervention has consistently listed age older than 80 years as a relative contraindication to the performance of CAS and considers this age group to be at a very high risk for complications.30 It can be argued that CAS is in its infancy and that it took many years for carotid endarterectomy to become as safe as it is today. Technological advances and increases in operator experience will lessen the overall number of complications after CAS. Lessening the rate of stroke in the octogenarian might prove to be particularly difficult. Aortic arch elongation, tortuosity of the common and internal carotid arteries, and increased calcification of the involved vessels, which all are increasingly common in the octoge-
J Am Coll Surg
narian, serve to increase the likelihood of cerebral embolization during CAS. Patients older than age 80 can be especially vulnerable to the microembolization that routinely follows this procedure. It is certain that CAS will play a role in the treatment of patients with carotid stenosis. It might prove to be superior to carotid endarterectomy in selected patients with recurrent carotid stenosis, severe concomitant medical comorbidities, or anatomically challenging anatomy. We must await the result of trials such as CREST to establish whether CAS is noninferior to carotid endarterectomy in patients at moderate or low risk for operation. It would appear from the available literature that carotid stenting is of greatest risk in the octogenarian, especially those who have had previous neurologic events. Carotid stenting in the elderly should be undertaken with caution and only in those with anatomy that is favorable to CAS. We conclude that carotid endarterectomy can be safely performed in octogenarians and that they are not at high risk for carotid endarterectomy. Age older than 80 years should no longer be used as an inclusion criterion for entry into trials of carotid stenting or used as a condition for reimbursement. It appears that although octogenarians are not at high risk for carotid endarterectomy, they constitute the highest-risk category of patients undergoing CAS. Carotid endarterectomy remains the treatment of choice in patients older than 80 years of age with substantial carotid stenosis. Author Contributions Study conception and design: Bremner, Katz Acquisition of data: Bremner Analysis and interpretation of data: Bremner, Katz Drafting of manuscript: Bremner, Katz Critical revision: Katz
REFERENCES 1. Fisher M. Occlusion of the internal carotid artery. AMA Arch Neuro Psychiatry 1951;65:346–377. 2. Eastcott HHG, Pickering GW, Rob CG. Reconstruction of internal carotid artery in a patient with intermittent attacks of hemiplegia. Lancet 1954;2:994–996. 3. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991;325:445–463. 4. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid stenosis. JAMA 1995;273:1421–1428. 5. Mohr JP. Stroke: pathophysiology, diagnosis, and management. 4th ed. Philadelphia: Churchill Livingstone; 2004:3–27. 6. Williams GR, Jiang JG, Matchar DB, et al. Incidence and occurrence of total (first-ever and recurrent) stroke. Stroke 1999; 30:2523–2528.
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7. Maxewell J, Taylor A, Brinker M, et al. Carotid endarterectomy in the community hospital in patients age 80 and older. Ann Surg 2000;231:781–788. 8. Fisher ES, Malenka DJ, Solomon NA, et al. Risk of carotid endarterectomy in the elderly. Am J Public Health 1989;79: 1617–1620. 9. Alozairi O, MacKenzie RK, Morgan R, et al. Carotid endarterectomy in patients aged 75 and over: early results and late outcome. Eur J Vasc Endovasc Surg 2003;26:245–249. 10. Pruner G, Castellano R, Jannello AM, et al. Carotid endarterectomy in the octogenarian: outcomes of 345 procedures performed from 1995⫺2000. Cardiovasc Surg 2003;11:105–112. 11. Kazmers A, Perkins AJ, Huber TS, et al. Carotid surgery in octogenarians in Veterans Affairs medical centers. J Surg Res 1999;81:87–90. 12. Schneider JR, Droste JS, Schindler N, et al. Carotid endarterectomy in octogenarians: comparison with patient characteristics and outcomes in younger patients. J Vasc Surg 2000;31:927–935. 13. Miller MT, Comerota AJ, Tzilinis A, et al. Carotid endarterectomy in octogenarians: does increased age indicate “high risk?” J Vasc Surg 2005;41:231–237. 14. O’Hara PJ, Hertzer NR, Masha EJ, et al. Carotid endarterectomy in octogenarians: early results and late outcome. J Vasc Surg 1998;27:860–871. 15. Maxwell JG, Rutherford EJ, Covington DL, et al. Community hospital carotid endarterectomy in patients over age 75. Am J Surg 1990;160:598–603. 16. Beebe HG, Clagett GP, DeWeese JA, et al. Assessing risk associated with carotid endarterectomy. A statement for health care professionals by Ad Hoc Committee on Carotid Surgery Standards of the Stroke Council, American Heart Association. Circulation 1989;79:472–473. 17. Petler BA, Williams GM. Carotid endarterectomy in the very elderly: is it worthwhile? Surgery 1994;116:479–483. 18. Treiman RL, Wagner WH, Foran RF, et al. Carotid endarterectomy in the elderly. Ann Vasc Surg 1992;6:321–324. 19. Moore WS, Barnett HM, Beebe HG, et al. Guidelines for carotid endarterectomy: a multidisciplinary consensus statement
20.
21. 22. 23. 24. 25. 26. 27.
28.
29. 30.
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from the ad hoc committee, American Heart Association. Stroke 1995;26:188–201. Biller J, Feinberg WM, Castaldo JE, et al. Guidelines for carotid endarterectomy: a statement for healthcare professionals from a special writing group of the stroke council, American Heart Association. Circulation 1998;97:501–509. Yadav J, Wholey M, Kuntz R, et al. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med 2004;351:1493–1501. Katz S, Kohl R. Does the choice of material influence early morbidity in patients undergoing carotid patch angioplasty? Surgery 1996;119:297–301. Katz S, Kohl R. Carotid endarterectomy with shortened hospital stay. Arch Surg 1995;130:887–891. Rosenthal D, Rudderman RH, Jones DH, et al. Carotid endarterectomy in the octogenarian: is it appropriate? J Vasc Surg 1986;3:782–787. Al-Mubarak N, Colomkbo A, Gaines PA, et al. Multicenter evaluation of carotid artery stenting with a filter protection system. J Am Coll Cardiol 2002;39:841–846. Castriota F, Cremonesi A, Manetti R, et al. Impact of cerebral protection devices on early outcome of carotid stenting. J Endovasc Ther 2002;9:786–792. Guidant Endovascular Solutions, Inc. Clinical update for physicians. RX ACCULINK Carotid Stent System PMAP040012, March 20, 2006. Indianapolis: Guidant Endovascular Solutions, Inc; 2006. Hobson RW, Howard G, Howard V, et al. Carotid artery stenting is associated with increased complications in octogenarians: 30-day stroke and death rates in the CREST lead-in phase. Paper presented at the Annual Meeting of the Society for Vascular Surgery, Anaheim, CA, June 5, 2004. Stanziale S, Criado F, Donaldson M. Is carotid stenting safe for octogenarians? J Vasc Surg 2006;43:297–304. Chastain HD, Gomez CR, Iyer S, et al. Influence of age upon complications of carotid artery stenting. UAB Neurovascular Angioplasty Team. J Endovasc Surg 1999;6:217–222.
In 1951, Fisher first postulated the link between extracranial carotid disease and stroke.1 Within the next few years, carotid resection by Eastcott and colleagues had been successfully performed to treat symptomatic carotid stenosis.2 During the ensuing 30 years, carotid endarterectomy became the most frequently performed vascular operation in the US, although its efficacy was anecdotal. In the early 1990s, several multiinstitutional prospective and randomized studies confirmed its efficacy in preventing stroke in both symptomatic and asymptomatic patients younger than 80 years of age.3,4 The number of octogenarians is expected to rapidly increase during the next several decades. This, coupled with the increasing likelihood of stroke and carotid bifurcation arteriosclerosis seen in this age group, makes proper treatment selection extremely important. Unfortunately, octo-
genarians were excluded from participation in the prospective and randomized studies that demonstrated the efficacy of carotid endarterectomy in preventing stroke in selected patients. Because of the perception that this age group is at increased risk from carotid endarterectomy, alternative treatment options, such as carotid artery stenting (CAS), have been suggested as a lower-risk alternative. Many of the trials evaluating CAS have used age older than 80 years as one of the high-risk criteria allowing entry into the studies. In fact, the Centers for Medicare and Medicaid Services use advanced age as justification for reimbursement for CAS. It is the purpose of this study to examine the morbidity of patients older than age 80 undergoing carotid endarterectomy in a single institution and determine if octogenarians are truly at high risk for carotid endarterectomy.
METHODS Records of all patients undergoing elective primary endarterectomy during a 12-year period were reviewed. Health Insurance Portability and Accountability Act⫺compliant, deidentified patient information was collected after IRB approval was obtained. Operative outcomes were determined by close review of the medical records, including outpatient visits. Routine neurologic examination was per-
Disclosure Information: Nothing to disclose. Received March 10, 2008; Revised May 5, 2008; Accepted May 6, 2008. From the Division of Vascular Surgery, University of Southern California, Keck School of Medicine, Los Angeles, CA (Katz) and Huntington Hospital, Pasadena, CA (Bremner). Correspondence address: Steven G Katz, MD, Office of Medical Education, Huntington Hospital, 100 W California Ave, Pasadena, CA 91105. email: [email protected]
© 2008 by the American College of Surgeons Published by Elsevier Inc.
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ISSN 1072-7515/08/$34.00 doi:10.1016/j.jamcollsurg.2008.05.002
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Octogenarians and Carotid Endarterectomy
J Am Coll Surg
Table 1. Preoperative Risk Factors Abbreviations and Acronyms
Risk factors
n
%
CAPTURE ⫽ Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Unanticipated or Rare Results CAS ⫽ carotid artery stenting CREST ⫽ Carotid Revascularization Endarterectomy Versus Stent Trial
Hypertension Hyperlipidemia Coronary artery disease Diabetes mellitus Smoking
76 38 28 17 42
80.0 40.0 29.5 17.9 44.2
formed by members of the vascular surgery service within 24 hours of carotid endarterectomy and again at 1 and 6 weeks after operation, and neurologic consultation was obtained when any deficit was noted. Duplex ultrasonography scans were obtained in all patients before operation, and cerebral arteriography was used to confirm results in equivocal patients. Symptomatic patients were operated on when the duplex scan revealed a stenosis of ⱖ 70%, and asymptomatic patients were operated on when a stenosis of 80% to 99% was detected. Duplex scan criteria for predicting a 70% stenosis included a peak systolic velocity ⱖ 230 cm/s combined with an internal carotid/common carotid peak systolic velocity ratio of at least 4. If, in addition to these findings, an end diastolic velocity was discovered, an 80% to 99% stenosis was diagnosed. Carotid endarterectomy was offered to all but a small number of patients with comorbidities of such severity that they were believed to substantially limit life expectancy. Such conditions included dialysis-dependent renal failure, class IV heart failure and angina, uncontrolled malignancy, oxygen-dependent respiratory failure, and severe neurologic impairment. Individual patients were used as data points in calculating demographics and risk factors, and each operation was considered separately in outcomes analysis. Carotid endarterectomies were performed under general anesthesia with continuous intraarterial pressure monitoring. All operations were performed by two surgeons who held certificates of special qualifications in vascular surgery from the American Board of Surgery. Cefazolin sodium was administered immediately before operation and continued for 24 hours postoperatively. Infusions of dextran 40 were begun on induction of anesthesia and continued for 24 hours. All patients were systemically anticoagulated with 5,000 U heparin before arterial clamping. Indwelling shunts were used in all patients, and all arteriotomies were closed using a Dacron patch (Boston Scientific). Protamine sulfate was used to reverse heparin anticoagulation at the conclusion of operation. Administration of 325 mg aspirin was begun 24 hours after operation and continued indefinitely. After operations, all patients were monitored in the postanesthetic recovery unit for 6 hours and transferred to a monitored bed on the surgical floor if hemodynamically
n ⫽ 95.
stable. Perioperative hypertension was controlled with topical nitrates and calcium channel blockers, and parenteral medications were used only if these measures failed to control blood pressure. Perioperative -blockade was used at the discretion of the operating surgeon and attending anesthesiologist. Patient demographics, preoperative risk factors, and indication for operation were recorded. Study outcome measures included perioperative (30-day) death, stroke, myocardial infarction, length of stay, cranial nerve injury, and hematoma requiring reoperation. Neurologic deficits lasting 24 hours or less were considered to be transient ischemic attacks. Those deficits lasting longer than 24 hours that resolved completely within 30 days were considered to be minor strokes, and all others were categorized as major strokes. Myocardial infarction was diagnosed when patients with postoperative chest pain, arrhythmia, or hemodynamic instability were found to have a creatine kinase level at least two times the normal limit with a positive MB fraction. Patients were followed for a minimum of 30 days postoperatively.
RESULTS Between January 1, 1995, and December 31, 2006, 103 carotid endarterectomies were performed in 95 patients 80 years of age or older. This represents 15.3% of endarterectomies performed during this time period. Fifty-nine patients were male and 36 were female. Their ages ranged from 80 to 94 years, with a mean of 83.7 years. Patient risk factors are listed in Table 1. Indication for operation included asymptomatic carotid stenosis in 57.3% of patients, earlier stroke with good recovery in 21.3%, transient hemispheric ischemia in 18.4%, and nonhemispheric symptoms in 2.9%. Median length of stay was 2 days (range 1 to 32 days). Outcome measures are summarized in Table 2. The patient experiencing the transient ischemic attack experienced a transient worsening of a preexisting aphasia, which returned to baseline within 12 hours. The two patients who had minor strokes experienced a mild contralateral upper extremity paresis, which resolved completely on postoperative days 2 and 3, respectively. The single major deficit
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Table 2. Perioperative Outcome Measures Outcome
n
%
Transient ischemic attack Minor stroke Major stroke Myocardial infarction Cranial nerve injury Hematoma
1 2 1 3 3 2
0.97 1.94 0.97 2.91 2.91 1.94
n ⫽ 103.
occurred in a patient who had suffered a stroke before the operation and had made a good recovery. On the first postoperative day, a dense hemiparesis developed, and the patient was found to have an intracranial hemorrhage thought to be secondary to a reperfusion injury. His deficits did not resolve, and he required placement in a skilled nursing facility. Two of the three patients suffering a myocardial infarction had known preexisting coronary artery disease. One had previous coronary artery bypass operation and the second had experienced a myocardial infarction 3 years before operation. The third patient had only moderate hypertension as a risk factor. Transient paresis of the marginal mandibular nerve developed in 3 patients and was resolved within 90 days. No other cranial nerve injuries were noted. An additional two patients required reexploration for evacuation of a hematoma. One patient was found to have an expanding hematoma in the recovery room and was immediately reexplored. The second patient had been discharged home on warfarin sodium for atrial fibrillation and returned 3 days after discharge with a hematoma requiring evacuation. There were no deaths within 30 days of operation. Combined stroke and death rate was 2.91%.
DISCUSSION Approximately 700,000 new and recurrent strokes occur in the US annually, and it is estimated that 10% to 20% of these are related to carotid artery disease.5,6 In the last 30 years, the number of patients older than age 85 has increased 3-fold, and the remainder of the population has increased by only 50%. It has been estimated that by the year 2030, the number of octogenarians in the US will have increased to 70,000,000.7 Because the incidence of stroke increases with age, it can be inferred that stroke-related disability will consume a very substantial part of the healthcare budget. It is crucial to identify strategies that can potentially limit the devastating consequences of ischemic stroke. Much of the confusion surrounding the risk and benefit of carotid endarterectomy in the elderly results from their exclusion from prospective and randomized studies that
Octogenarians and Carotid Endarterectomy
551
proved the efficacy of carotid endarterectomy in both symptomatic and asymptomatic patients. The reason for their omission was most likely several-fold. A population study performed by Fisher and colleagues in 1989, suggested that patients older than 80 years of age had a 4-fold increase in mortality after carotid endarterectomy, and other studies seemed to confirm this finding.8-11 More recent studies have shown a decline in perioperative morbidity and mortality that appears to extend to octogenarians, suggesting that their risk is not prohibitive.7,12-14 At the time of initiation of the North American Symptomatic Carotid Endarterectomy Trial and Asymptomatic Carotid Atherosclerosis Study, there was a concern that octogenarians would not live long enough to benefit from endarterectomy. For Caucasian men reaching age 80, the life expectancy is 7.2 years and for women it is 9.1 years.15,16 We acknowledge that these statistics might not totally represent life expectancy in 80-year-olds with systemic arteriosclerosis. Because both symptomatic and asymptomatic patients gain benefit from carotid endarterectomy after 3 years, it would appear that octogenarians survive long enough to achieve a decrease in stroke morbidity from operative intervention. Although our study only focuses on the safety of endarterectomy, others have demonstrated its efficacy in those older than 80 years of age. In fact, 2 studies have shown that, on average, 80% of octogenarians survive at least 4 years after endarterectomy and that the vast majority are stroke free at 5 to 10 years.12,17 Recent studies have questioned routine categorization of those older than 80 years of age as being at high risk for carotid endarterectomy. Although some authors have suggested that octogenarians are at a higher risk for complications after endarterectomy, a number of others disagree. A recently published pooled analysis of ⬎ 2,500 patients reported a combined stroke mortality of 3.45% after carotid endarterectomy in octogenarians.13 Several articles have determined that there exists no substantial increase in combined stroke and death end points after endarterectomy when patients older than 80 are compared with a younger cohort.12,13,18 Results in our series tend to bear this out. Our overall combined stroke and death rate of 2.91% (4.65% in symptomatic and 1.75% in asymptomatic patients) fall well within the guidelines established by the Stroke Council of the American Heart Association.16,19-21 These results compare favorably with the 2.2% stroke and death rate reported in our previous publications that included a younger cohort of patients.22,23 It is also important to note that only 1 patient (0.97%) experienced a major stroke with a resultant permanent neurologic deficit. In contrast, a study of octogenarians with carotid stenosis who did not undergo intervention had a 16% rate of cerebral infarction,
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Octogenarians and Carotid Endarterectomy
and 50% of this group required nursing home care and remained nonambulatory during longterm followup.24 This underscores the importance of offering carotid endarterectomy to patients older than 80 years of age who have a substantial carotid stenosis. Introduction of CAS has created controversy about its role in the treatment of patients with extracranial cerebrovascular disease. In experienced hands, CAS can be performed with a technical success rate of ⬎ 97% and a stroke rate of ⱕ 5% when performed in the general population of patients with substantial carotid stenosis.25,26 Advocates of CAS have championed its use in high-risk patients, defined as those excluded from the North American Symptomatic Carotid Endarterectomy Trial and Asymptomatic Carotid Atherosclerosis Study, and octogenarians constitute a large segment of this population. Although results of recent studies have demonstrated that the results of carotid endarterectomy do not differ substantially between patients aged 80 years and older and their younger counterparts, the same cannot be said for CAS. In the Carotid ACCULINK/ ACCUNET Post Approval Trial to Uncover Unanticipated or Rare Results (CAPTURE), the overall 30-day stroke, myocardial infarction, and death rate for patients older than 80 years of age was 7.7%, and it was 4.3% for younger patients. This difference was statistically significant. When results of those who were asymptomatic were separately analyzed (90% of patients), this difference persisted.27 In the lead-in phase of the Carotid Revascularization Endarterectomy Versus Stent Trial (CREST), octogenarians undergoing CAS performed by experienced interventionalists had a 30-day stroke and death rate of 12.1%, which is considerably higher than similar results reported for carotid endarterectomy in this and other studies.28 A study from the University of Pittsburgh reported a 30-day rate of stroke, death, and myocardial infarction of 9.2% in octogenarians and 3.4% in younger patients after CAS, a result that was statistically significant.29 It is especially interesting to note that 1 of the groups most experienced in carotid intervention has consistently listed age older than 80 years as a relative contraindication to the performance of CAS and considers this age group to be at a very high risk for complications.30 It can be argued that CAS is in its infancy and that it took many years for carotid endarterectomy to become as safe as it is today. Technological advances and increases in operator experience will lessen the overall number of complications after CAS. Lessening the rate of stroke in the octogenarian might prove to be particularly difficult. Aortic arch elongation, tortuosity of the common and internal carotid arteries, and increased calcification of the involved vessels, which all are increasingly common in the octoge-
J Am Coll Surg
narian, serve to increase the likelihood of cerebral embolization during CAS. Patients older than age 80 can be especially vulnerable to the microembolization that routinely follows this procedure. It is certain that CAS will play a role in the treatment of patients with carotid stenosis. It might prove to be superior to carotid endarterectomy in selected patients with recurrent carotid stenosis, severe concomitant medical comorbidities, or anatomically challenging anatomy. We must await the result of trials such as CREST to establish whether CAS is noninferior to carotid endarterectomy in patients at moderate or low risk for operation. It would appear from the available literature that carotid stenting is of greatest risk in the octogenarian, especially those who have had previous neurologic events. Carotid stenting in the elderly should be undertaken with caution and only in those with anatomy that is favorable to CAS. We conclude that carotid endarterectomy can be safely performed in octogenarians and that they are not at high risk for carotid endarterectomy. Age older than 80 years should no longer be used as an inclusion criterion for entry into trials of carotid stenting or used as a condition for reimbursement. It appears that although octogenarians are not at high risk for carotid endarterectomy, they constitute the highest-risk category of patients undergoing CAS. Carotid endarterectomy remains the treatment of choice in patients older than 80 years of age with substantial carotid stenosis. Author Contributions Study conception and design: Bremner, Katz Acquisition of data: Bremner Analysis and interpretation of data: Bremner, Katz Drafting of manuscript: Bremner, Katz Critical revision: Katz
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