- Email: [email protected]
Carotid Angiography in Contemporary Vascular Surgery Practice
Carotid Angiography in Contemporary Vascular Surgery Practice Eugene M. Langan III, MD*, Bruce H. Gray, MD*, and Timothy M. Sullivan, MD, FACS† While most patients with carotid artery disease can safely undergo carotid endarterectomy based on duplex ultrasound alone, carotid angioplasty and stenting must, by its nature, be performed in conjunction with carotid arteriography. The techniques of carotid angiography are a necessary prerequisite to carotid intervention. The indications, technique, and results of carotid angiography in a contemporary vascular surgery practice are described. Semin Vasc Surg 18:83-86 © 2005 Elsevier Inc. All rights reserved.
D
UPLEX ULTRASONOGRAPHY OF patients with suspected extracranial carotid stenosis remains the screening test of choice. In the past, carotid angiography was routinely performed in all patients considered for carotid endarterectomy (CEA); with the advent of superior duplex ultrasound technology, most vascular surgeons now perform CEA based on duplex alone, with satisfactory results. This policy is cost-effective, safe, and avoids the small but definite risk of an invasive angiographic procedure. As vascular surgeons become more involved in carotid angioplasty/stenting (CAS), the catheter skills required to perform diagnostic carotid angiography have become increasingly important. We examined the indications for carotid angiography in a contemporary vascular surgery practice to evaluate its safety when performed by vascular surgeons trained in catheterbased techniques.1
Methods The clinical records and arteriographic studies of 164 consecutive patients having selective arteriography of the extracranial carotid arteries by members of the Vascular Surgery Service at the Greenville Hospital System during a 19month period from September 2000 through March 2002 were retrospectively reviewed from a prospective database. The study protocol was approved by the Institutional Review Committee of the Greenville Hospital System, Greenville, SC. Patients gave consent for the arteriographic procedure, and were informed as to its potential risks and benefits. All arte-
*Department of Surgery, Greenville Hospital System, Greenville, SC and †Division of Vascular Surgery, Mayo Clinic, Rochester, MN. Address reprint requests to Timothy M. Sullivan, Division of Vascular Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905. E-mail: [email protected]
0895-7967/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.semvascsurg.2005.04.004
riographic procedures were performed in a dedicated endovascular operating room with fixed, single-plane ceilingmounted angiographic equipment or in the Department of Radiology, also using fixed equipment. No procedures were performed using portable C-arms. The study group consisted of 95 men and 69 women. Patients were excluded from this study if they had only an arch aortogram performed (without selective brachiocephalic catheterization) or if their angiogram was performed as part of an interventional procedure, such as carotid stenting. Following routine sterile skin preparation and draping, patients were given light conscious sedation administered by a certified nurse anesthetist or a registered nurse with expertise in conscious sedation. All patients were currently being treated with aspirin; the concurrent use of clopidogrel, ticlopidine, or heparin was not considered a contraindication to the procedure. If the use of a percutaneous closure device was anticipated, patients were given intravenous antibiotics prior to skin puncture. The patient’s head was placed in a cradle to reduce motion during contrast injection and image acquisition. Following local infiltration of 1% lidocaine, percutaneous access was achieved with a 5Fr sheath. All procedures were performed via retrograde femoral access; upper extremity access was not utilized in this series. All patients received intravenous heparin, typically 50 to 100 U/kg body mass prior to manipulation of wires and catheters in the aortic arch or brachiocephalic trunks. Activated clotting time was typically not measured. All but one patient had a diagnostic arch aortogram prior to selective catheterization, typically in the 30-degree left anterior oblique projection to maximize visualization of the brachiocephalic trunk origins. Selective brachiocephalic catheterization was performed with 5Fr end-hole diagnostic catheters; the configuration of the catheter was selected based on the anatomy of the aortic 83
E.M. Langan, B.H. Gray, and T.M. Sullivan
84 Table 1 Indications for Carotid Arteriography in 164 Patients Indication
n
%
Hemispheric symptoms with <80% stenosis by duplex ultrasound Suspected proximal brachiocephalic trunk stenosis Unclear anatomy by duplex ultrasound Recurrent carotid stenosis (previous CEA) Symptomatic >80% carotid stenosis Ipsilateral internal carotid occlusion Bilateral >80% carotid stenosis by duplex ultrasound Vertebral-basilar ischemia Contralateral internal carotid occlusion Duplex ultrasound from a nonaccredited vascular lab Nonatherosclerotic carotid disease
34
20.6
26
15.8
17 17 16 12 12
10.3 10.3 9.8 7.1 7.1
11 9 5
7.0 5.4 3.3
5
3.3
Abbreviation: CEA, carotid endarterectomy. From Sullivan et al.1 Reprinted with permission.
arch and brachiocephalic trunks. Typically, a headhunter (H-1) or Simmons II (Sim2) catheter was used. A soft angled glide wire was often used to assist in selective catheterization. Hallmarks of the procedure included minimal manipulation of the arch and carotid vessels and careful attention to proper catheter flushing to avoid potential embolization of thrombus that may have formed on the catheter. Once the catheter had been advanced into the mid common carotid artery, selective contrast arteriography of the carotid bifurcation in at least two views was performed either by hand injection or via a power injector. Typically, 5 to 7 cc contrast was required to visualize the carotid bifurcation, while larger amounts were utilized (7 to 12 cc) to visualize the intracranial circulation. Two views of each cerebral hemisphere were performed. If visualization of the posterior circulation was indicated, the catheter was placed in the subclavian artery to allow identification of the vertebral arteries; selective catheterization of the vertebral arteries was seldom performed. For patients with symptoms suggestive of vertebral-basilar ischemia, provocative maneuvers, eg, neck rotation, were utilized based on the patients presenting history. Following termination of the procedure, the catheter and sheath were removed, and hemostasis was achieved using manual compression or a percutaneous closure device; heparin anticoagulation was not reversed. If evaluated on an outpatient basis, patients were allowed to ambulate after 1 hour (for those with closure devices) and were discharged home. For patients whose puncture site was managed with manual compression, ambulation was allowed 2 to 4 hours following sheath removal.
Results The indications for carotid arteriography are listed in Table 1. The most common indication for arteriography was in patients with hemispheric symptoms and noncritical carotid stenosis by duplex ultrasound. A small number (9.8%) had symptomatic high-grade carotid stenosis (⬍80% by duplex);
further evaluation by arteriography was performed at the discretion of the patient’s attending vascular surgeon. Twelve patients had suspected internal carotid occlusion, which was further evaluated by arteriography; the majority (9 of 12, 75%) had confirmation of their duplex finding. An additional group had arteriography to define the degree of carotid stenosis with either a contralateral occlusion or high-grade contralateral stenosis. A total of 372 brachiocephalic arteries were selectively cannulated. Groin hematomas occurred in two patients (1.8%); neither required surgical intervention, although this complication did prolong their hospital stay. One patient had an exacerbation of congestive heart failure and required temporary mechanical ventilation. There were no transient ischemic attacks (TIA), strokes or deaths related to the index procedure. Seventy-nine patients (48.2%) went on to surgery, 71 were felt to have nonsurgical lesions and were treated medically, and 14 (8.5%) had CAS as part of two US Food and Drug Administration-approved trials of CAS in high-risk patients. During the study period, 282 CEAs were performed; 203 (71.9%) were operated based on the results of duplex ultrasound alone.
Discussion Prior to the advent of high-quality duplex ultrasound of the extracranial carotid arteries, contrast arteriography was the only method of evaluating patients who might benefit from carotid endarterectomy. In the mid-1980s, several investigators began to investigate the utility of duplex ultrasound as the sole imaging modality prior to CEA. Ricotta et al,2 in 1984, reported on 111 consecutive patients undergoing evaluation of carotid disease in anticipation of CEA. All patients had oculoplethysmography-Gee and duplex ultrasound as well as selective carotid arteriography. They concluded that arteriography provided no additional information in over two thirds of their patients with either hemispheric symptoms or asymptomatic cervical bruits. In contrast, they found that nearly all patients with nonhemispheric symptoms required an arteriogram for adequate evaluation prior to surgery. A number of centers in the United States and abroad have performed carotid endarterectomy based on duplex ultrasound alone. Loftus et al3 from the University of Leicester, UK evaluated 494 CEAs performed over a 4-year period. Only 35 of these patients had preoperative arteriography. They concluded that the use of duplex as the sole preoperative imaging tool did not compromise the safety of the operation. Logason and colleagues,4 in a series of 287 CEAs in 271 patients, performed 80% of these operations based on duplex alone. In only one case (of 230 operations) were there unexpected findings at surgery that had not been identified on preoperative duplex imaging. The addition of angiography increases the cost of preoperative evaluation substantially. Kasper et al5 evaluated 123 consecutive carotid endarterectomies performed at a community teaching hospital. All patients had preoperative duplex ultrasonography; 28 patients had a carotid arteriogram. Duplex ultrasound, on average, was $165,
Carotid angiography in contemporary vascular surgery practice while the additional cost incurred by an arteriogram was $4,200, and was associated with substantial morbidity in their series. Others have also stressed the use of duplex ultrasound (and avoidance of catheter angiography) in reducing the cost of CEA.6 In our series, the vast majority (71.9%) of CEAs were performed based on duplex ultrasound alone. While duplex ultrasound can be utilized as the sole preoperative imaging study in the majority of patients, it does have certain limitations. It may overestimate the degree of carotid stenosis in patients with contralateral high-grade internal carotid artery (ICA) stenosis or occlusion,7,8 although criteria have been established to correct for this discrepancy.9 In the current series, arteriography was performed for this indication in less than 15% of cases. Other noninvasive modalities have been utilized to supplement duplex ultrasound prior to CEA in selected instances, including gadolinium-enhanced magnetic resonance angiography (MRA)10 and three-dimensional helical computed tomography,11,12 and are discussed in the preceding Seminars article by Kaufman and Kallmes. While many centers utilize MRA as an important adjunct to duplex in evaluation of patients with carotid disease, this practice is not universal.13 Neither high-quality MRA nor CT angiography were available at our institution during the study period; the presence of these two imaging modalities has, however, decreased our current utilization of catheter angiography for diagnostic purposes. While it remains an important adjunct in the evaluation of patients with carotid occlusive disease, the risk of catheter angiography should not be underestimated. It has been associated with access-site bleeding, contrast reaction, and with stroke. In the Asymptomatic Carotid Atherosclerosis Study, the overall risk of stroke and death in those patients randomized to surgery was 2.3%; more than half that risk (1.2%) was attributed to carotid arteriography.14 The reported incidence of this complication is between 0.5% and 4%, and stresses the importance of meticulous technique in performing this procedure. Given its invasive nature, its cost relative to duplex ultrasound, and the risk of significant complications, selective criteria for use have been proposed. Dawson et al15 prospectively evaluated 103 patients with carotid disease, the majority of whom were symptomatic. All patients underwent duplex scanning and arteriography; the utility of arteriography was determined by a multispecialty panel. Following review of noninvasive studies, 29% were believed to require arteriography for specific indications. In one third of these patients, management decisions were altered on the basis of the arteriogram. Their indications for arteriography included (1) 50% to 79% carotid stenosis by duplex with confounding variables such as unclear symptoms, question of ulceration, or poor operative risk, (2) highgrade ICA stenosis opposite an ICA occlusion, (3) nonatherosclerotic disease, (4) to confirm an ICA occlusion, (5) suggestion of proximal disease, (6) symptoms of vertebralbasilar ischemia, and (7) suboptimal duplex ultrasound. We have used these criteria as selected indications for carotid arteriography. In addition, we studied patients with recurrent carotid stenosis, those with contralateral high-grade
85 Table 2 Indications for Arteriography (Schneider et al 2005) Indications
%
Define carotid occlusive disease Define etiology of hemorrhage Intracranial aneurysm/AVM Evaluate vasospasm Trauma Tumor Vasculitis Congenital/anatomic anomaly Venous occlusive disease
86 3 2 <1 5 2 1 <1 <1
Abbreviation: AVM, arteriovenous malformation. Reprinted with permission from The Society for Vascular Surgery.16
(⬎80%) ICA stenosis, and those with symptomatic highgrade (⬎80%) ICA stenosis at the discretion of the attending vascular surgeon. In addition, patients being considered for carotid angioplasty and stenting may benefit from a complete diagnostic study (as a separate procedure) prior to CAS to assist in decision making and treatment planning, especially in those just embarking on a program of CAS. Schneider et al16 have recently reported their experience with carotid angiography in 503 patients over a period of 45 months from three separate institutions. The majority of their patients were symptomatic (TIA, 35%; prior stroke, 24%; vertebrobasilar ischemia/nonspecific symptoms, 7%), while only 34% underwent angiography for asymptomatic disease. Indications for angiography are listed in Table 2. The indications and results of these procedures were compared with quality standards for the performance of carotid angiography from a cooperative study of the American Society of Interventional and Therapeutic Neuroradiology, the American Society of Neuroradiology, and the Society of Cardiovascular and Interventional Radiology.17 Thresholds that should be met or exceeded by physicians performing diagnostic carotid angiography include appropriateness of indication (Table 3) in 99% and a success rate of 98%. Acceptable levels of neurologic and nonneurologic complications include reversible neurologic defecit, TIA, and reversible stroke (2.5%), permanent neurologic deficit (1%), renal failure (0.2%), access site arterial occlusion (0.2%), pseudoaneurysm/arteriovenous fistula (0.2%), and hemorrhage requiring transfusion/evacuation (0.5%) are defined. The rate of all major complications should not exceed 2.0%. In both cited studies performed and reported on by vascular surgeons,1,16 these thresholds for indication and complications are met. As catheter-based therapy becomes increasingly integrated into vascular surgery practice,18 vascular surgeons will be required to incorporate carotid arteriography into their skill sets. We have favored relatively restrictive criteria for its use, while others have proposed a more liberal approach. Given the high-profile nature of diagnostic and therapeutic procedures in this particular circulatory bed, a strong foundation of endovascular skills in other territories is mandatory. In addition, surgeons need to be well-versed in selective cannulation of the brachiocephalic trunks and diagnostic arteriography prior to delving into the arena of carotid intervention.
E.M. Langan, B.H. Gray, and T.M. Sullivan
86 Table 3 Appropriate Indications for Adult Diagnostic Neuroangiography17 1. Define presence or extent of vascular occlusive disease and thromboembolic phenomenon 2. Define etiology of hemorrhage (subarachnoid, intraventricular, parenchymal, and craniofacial) 3. Define presence, location, anatomy of intracranial aneurysms and vascular malformations 4. Evaluate vasospasm related to subarachnoid hemorrhage 5. Define presence or extent of trauma to cervicocerebral vessels (eg, dissection, pseudoaneurysm) 6. Define vascular supply to tumors 7. Define presence or extent of vasculitis (infectious, inflammatory, or drug-induced) 8. Diagnose and/or define congenital or anatomic anomaly 9. Define presence of venous occlusive disease 10. Outline vascular anatomy for planning and determining the effect of therapeutic measures 11. Perform physiologic testing of brain function
4.
5.
6. 7.
8.
9.
10.
11.
Again, proper patient selection and meticulous attention to detail are paramount. 12.
Conclusions Diagnostic carotid arteriography via selective brachiocephalic catheterization can be safely performed by vascular surgeons with expertise in peripheral endovascular procedures. Selective arteriography of the carotid arteries remains an important adjunct in the evaluation of patients with carotid disease. Adherence to published guidelines regarding indications and results is mandatory. Selective brachiocephalic catheterization is an important skill set for the vascular surgeon to master as a segue to carotid angioplasty and stenting.
13.
14.
15.
16.
References 1. Sullivan TM, Patel A, Langan EM et al: Can carotid angiography be performed by vascular surgeons? A critical evaluation of indications, technique, and results. Ann Vasc Surg 18:710-713, 2004 2. Ricotta JJ, Holen J, Schenk E, et al: Is routine angiography necessary prior to carotid endarterectomy? J Vasc Surg 1:96-102, 1984 3. Loftus IM, McCarthy MJ, Pau H, et al: Carotid endarterectomy without
17.
18.
angiography does not compromise operative outcome. Eur J Vasc Endovasc Surg 16:489-493, 1998 Logason K, Karacagil S, Hardemark HG, et al: Carotid endarterectomy solely based on duplex scan findings. Vasc Endovasc Surg 36:9-15, 2002 Kasper GC, Lohr JM, Welling RE: Clinical benefit of carotid endarterectomy based on duplex ultrasonography. Vasc Endovasc Surg 37:323327, 2003 Sandison AJ, Wood CH, Padayachee TS, et al: Cost-effective carotid endarterectomy. Br J Surg 87:323-327, 2000 Spadone DP, Barkmeier LD, Hodgson KJ, et al: Contralateral internal carotid artery stenosis or occlusion: Pitfall of correct ipsilateral classification.—A study performed with color-flow imaging. J Vasc Surg 11: 642-649, 1990 AbuRahma AF, Richmond BK, Robinson PA, et al: Effect of contralateral severe stenosis or carotid occlusion on duplex criteria of ipsilateral stenoses: Comparative study on various duplex parameters. J Vasc Surg 22:751-762, 1995 Fujatani RM, Mills JL, Wang LM, Taylor SM: The effect of unilateral internal carotid arterial occlusion upon contralateral duplex study: Criteria for accurate interpretation. J Vasc Surg 16:459-468, 1992 Johnston DC, Eastwood JD, Nguyen T, Goldstein LB: Contrast-enhanced magnetic resonance angiography of carotid arteries: Utility in routine clinical practice. Stroke 33:2834-2838, 2002 Sameshima T, Futami S, Morita Y, et al: Clinical usefulness of and problems with three-dimensional CT angiography for the evaluation of arteriosclerotic stenosis of the carotid artery: Comparison with conventional angiography, MRA and ultrasound sonography. Surg Neurol 51:301-308, 1999 De Monti M, Ghilardi G, Caverni L, et al: Multidetector helical angio CT oblique reconstructions orthogonal to internal carotid artery for preoperative evaluation of stenosis. A perspective study of comparison with US color Doppler, digital subtraction angiography and intraoperative data. Minerva Cardioangiol 51:373-385, 2003 Erdoes LS, Marek JM, Mills JL, et al: The relative contributions of carotid duplex scanning, magnetic resonance angiography, and cerebral arteriography to clinical decision making: A prospective study in patients with carotid occlusive disease. J Vasc Surg 23:950-956, 1996 Executive Committee for the Asymptomatic Carotid Atherosclerosis Study: Endarterectomy for asymptomatic carotid artery stenosis. JAMA 273:1421-1428, 1995 Dawson DL, Zierler RE, Strandness DE, et al: The role of duplex scanning and arteriography before carotid endarterectomy: A prospective study. J Vasc Surg 18:673-683, 1993 Schneider PA, Silva MB, Bohannon WT, et al: Safety and efficacy of carotid angiography in vascular surgery practice. J Vasc Surg 41:238245, 2005 Cooperative study between ASITN, ASNR, and SCVIR: Quality improvement guidelines for adult diagnostic neuroangiography. Am J Neuroradiol 21:146-150, 2000 Sullivan TM, Taylor SM, Blackhurst DW, et al. Has endovascular surgery reduced the number of open vascular operations performed by an established surgical practice? J Vasc Surg 36:514-519, 2002
D
UPLEX ULTRASONOGRAPHY OF patients with suspected extracranial carotid stenosis remains the screening test of choice. In the past, carotid angiography was routinely performed in all patients considered for carotid endarterectomy (CEA); with the advent of superior duplex ultrasound technology, most vascular surgeons now perform CEA based on duplex alone, with satisfactory results. This policy is cost-effective, safe, and avoids the small but definite risk of an invasive angiographic procedure. As vascular surgeons become more involved in carotid angioplasty/stenting (CAS), the catheter skills required to perform diagnostic carotid angiography have become increasingly important. We examined the indications for carotid angiography in a contemporary vascular surgery practice to evaluate its safety when performed by vascular surgeons trained in catheterbased techniques.1
Methods The clinical records and arteriographic studies of 164 consecutive patients having selective arteriography of the extracranial carotid arteries by members of the Vascular Surgery Service at the Greenville Hospital System during a 19month period from September 2000 through March 2002 were retrospectively reviewed from a prospective database. The study protocol was approved by the Institutional Review Committee of the Greenville Hospital System, Greenville, SC. Patients gave consent for the arteriographic procedure, and were informed as to its potential risks and benefits. All arte-
*Department of Surgery, Greenville Hospital System, Greenville, SC and †Division of Vascular Surgery, Mayo Clinic, Rochester, MN. Address reprint requests to Timothy M. Sullivan, Division of Vascular Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905. E-mail: [email protected]
0895-7967/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.semvascsurg.2005.04.004
riographic procedures were performed in a dedicated endovascular operating room with fixed, single-plane ceilingmounted angiographic equipment or in the Department of Radiology, also using fixed equipment. No procedures were performed using portable C-arms. The study group consisted of 95 men and 69 women. Patients were excluded from this study if they had only an arch aortogram performed (without selective brachiocephalic catheterization) or if their angiogram was performed as part of an interventional procedure, such as carotid stenting. Following routine sterile skin preparation and draping, patients were given light conscious sedation administered by a certified nurse anesthetist or a registered nurse with expertise in conscious sedation. All patients were currently being treated with aspirin; the concurrent use of clopidogrel, ticlopidine, or heparin was not considered a contraindication to the procedure. If the use of a percutaneous closure device was anticipated, patients were given intravenous antibiotics prior to skin puncture. The patient’s head was placed in a cradle to reduce motion during contrast injection and image acquisition. Following local infiltration of 1% lidocaine, percutaneous access was achieved with a 5Fr sheath. All procedures were performed via retrograde femoral access; upper extremity access was not utilized in this series. All patients received intravenous heparin, typically 50 to 100 U/kg body mass prior to manipulation of wires and catheters in the aortic arch or brachiocephalic trunks. Activated clotting time was typically not measured. All but one patient had a diagnostic arch aortogram prior to selective catheterization, typically in the 30-degree left anterior oblique projection to maximize visualization of the brachiocephalic trunk origins. Selective brachiocephalic catheterization was performed with 5Fr end-hole diagnostic catheters; the configuration of the catheter was selected based on the anatomy of the aortic 83
E.M. Langan, B.H. Gray, and T.M. Sullivan
84 Table 1 Indications for Carotid Arteriography in 164 Patients Indication
n
%
Hemispheric symptoms with <80% stenosis by duplex ultrasound Suspected proximal brachiocephalic trunk stenosis Unclear anatomy by duplex ultrasound Recurrent carotid stenosis (previous CEA) Symptomatic >80% carotid stenosis Ipsilateral internal carotid occlusion Bilateral >80% carotid stenosis by duplex ultrasound Vertebral-basilar ischemia Contralateral internal carotid occlusion Duplex ultrasound from a nonaccredited vascular lab Nonatherosclerotic carotid disease
34
20.6
26
15.8
17 17 16 12 12
10.3 10.3 9.8 7.1 7.1
11 9 5
7.0 5.4 3.3
5
3.3
Abbreviation: CEA, carotid endarterectomy. From Sullivan et al.1 Reprinted with permission.
arch and brachiocephalic trunks. Typically, a headhunter (H-1) or Simmons II (Sim2) catheter was used. A soft angled glide wire was often used to assist in selective catheterization. Hallmarks of the procedure included minimal manipulation of the arch and carotid vessels and careful attention to proper catheter flushing to avoid potential embolization of thrombus that may have formed on the catheter. Once the catheter had been advanced into the mid common carotid artery, selective contrast arteriography of the carotid bifurcation in at least two views was performed either by hand injection or via a power injector. Typically, 5 to 7 cc contrast was required to visualize the carotid bifurcation, while larger amounts were utilized (7 to 12 cc) to visualize the intracranial circulation. Two views of each cerebral hemisphere were performed. If visualization of the posterior circulation was indicated, the catheter was placed in the subclavian artery to allow identification of the vertebral arteries; selective catheterization of the vertebral arteries was seldom performed. For patients with symptoms suggestive of vertebral-basilar ischemia, provocative maneuvers, eg, neck rotation, were utilized based on the patients presenting history. Following termination of the procedure, the catheter and sheath were removed, and hemostasis was achieved using manual compression or a percutaneous closure device; heparin anticoagulation was not reversed. If evaluated on an outpatient basis, patients were allowed to ambulate after 1 hour (for those with closure devices) and were discharged home. For patients whose puncture site was managed with manual compression, ambulation was allowed 2 to 4 hours following sheath removal.
Results The indications for carotid arteriography are listed in Table 1. The most common indication for arteriography was in patients with hemispheric symptoms and noncritical carotid stenosis by duplex ultrasound. A small number (9.8%) had symptomatic high-grade carotid stenosis (⬍80% by duplex);
further evaluation by arteriography was performed at the discretion of the patient’s attending vascular surgeon. Twelve patients had suspected internal carotid occlusion, which was further evaluated by arteriography; the majority (9 of 12, 75%) had confirmation of their duplex finding. An additional group had arteriography to define the degree of carotid stenosis with either a contralateral occlusion or high-grade contralateral stenosis. A total of 372 brachiocephalic arteries were selectively cannulated. Groin hematomas occurred in two patients (1.8%); neither required surgical intervention, although this complication did prolong their hospital stay. One patient had an exacerbation of congestive heart failure and required temporary mechanical ventilation. There were no transient ischemic attacks (TIA), strokes or deaths related to the index procedure. Seventy-nine patients (48.2%) went on to surgery, 71 were felt to have nonsurgical lesions and were treated medically, and 14 (8.5%) had CAS as part of two US Food and Drug Administration-approved trials of CAS in high-risk patients. During the study period, 282 CEAs were performed; 203 (71.9%) were operated based on the results of duplex ultrasound alone.
Discussion Prior to the advent of high-quality duplex ultrasound of the extracranial carotid arteries, contrast arteriography was the only method of evaluating patients who might benefit from carotid endarterectomy. In the mid-1980s, several investigators began to investigate the utility of duplex ultrasound as the sole imaging modality prior to CEA. Ricotta et al,2 in 1984, reported on 111 consecutive patients undergoing evaluation of carotid disease in anticipation of CEA. All patients had oculoplethysmography-Gee and duplex ultrasound as well as selective carotid arteriography. They concluded that arteriography provided no additional information in over two thirds of their patients with either hemispheric symptoms or asymptomatic cervical bruits. In contrast, they found that nearly all patients with nonhemispheric symptoms required an arteriogram for adequate evaluation prior to surgery. A number of centers in the United States and abroad have performed carotid endarterectomy based on duplex ultrasound alone. Loftus et al3 from the University of Leicester, UK evaluated 494 CEAs performed over a 4-year period. Only 35 of these patients had preoperative arteriography. They concluded that the use of duplex as the sole preoperative imaging tool did not compromise the safety of the operation. Logason and colleagues,4 in a series of 287 CEAs in 271 patients, performed 80% of these operations based on duplex alone. In only one case (of 230 operations) were there unexpected findings at surgery that had not been identified on preoperative duplex imaging. The addition of angiography increases the cost of preoperative evaluation substantially. Kasper et al5 evaluated 123 consecutive carotid endarterectomies performed at a community teaching hospital. All patients had preoperative duplex ultrasonography; 28 patients had a carotid arteriogram. Duplex ultrasound, on average, was $165,
Carotid angiography in contemporary vascular surgery practice while the additional cost incurred by an arteriogram was $4,200, and was associated with substantial morbidity in their series. Others have also stressed the use of duplex ultrasound (and avoidance of catheter angiography) in reducing the cost of CEA.6 In our series, the vast majority (71.9%) of CEAs were performed based on duplex ultrasound alone. While duplex ultrasound can be utilized as the sole preoperative imaging study in the majority of patients, it does have certain limitations. It may overestimate the degree of carotid stenosis in patients with contralateral high-grade internal carotid artery (ICA) stenosis or occlusion,7,8 although criteria have been established to correct for this discrepancy.9 In the current series, arteriography was performed for this indication in less than 15% of cases. Other noninvasive modalities have been utilized to supplement duplex ultrasound prior to CEA in selected instances, including gadolinium-enhanced magnetic resonance angiography (MRA)10 and three-dimensional helical computed tomography,11,12 and are discussed in the preceding Seminars article by Kaufman and Kallmes. While many centers utilize MRA as an important adjunct to duplex in evaluation of patients with carotid disease, this practice is not universal.13 Neither high-quality MRA nor CT angiography were available at our institution during the study period; the presence of these two imaging modalities has, however, decreased our current utilization of catheter angiography for diagnostic purposes. While it remains an important adjunct in the evaluation of patients with carotid occlusive disease, the risk of catheter angiography should not be underestimated. It has been associated with access-site bleeding, contrast reaction, and with stroke. In the Asymptomatic Carotid Atherosclerosis Study, the overall risk of stroke and death in those patients randomized to surgery was 2.3%; more than half that risk (1.2%) was attributed to carotid arteriography.14 The reported incidence of this complication is between 0.5% and 4%, and stresses the importance of meticulous technique in performing this procedure. Given its invasive nature, its cost relative to duplex ultrasound, and the risk of significant complications, selective criteria for use have been proposed. Dawson et al15 prospectively evaluated 103 patients with carotid disease, the majority of whom were symptomatic. All patients underwent duplex scanning and arteriography; the utility of arteriography was determined by a multispecialty panel. Following review of noninvasive studies, 29% were believed to require arteriography for specific indications. In one third of these patients, management decisions were altered on the basis of the arteriogram. Their indications for arteriography included (1) 50% to 79% carotid stenosis by duplex with confounding variables such as unclear symptoms, question of ulceration, or poor operative risk, (2) highgrade ICA stenosis opposite an ICA occlusion, (3) nonatherosclerotic disease, (4) to confirm an ICA occlusion, (5) suggestion of proximal disease, (6) symptoms of vertebralbasilar ischemia, and (7) suboptimal duplex ultrasound. We have used these criteria as selected indications for carotid arteriography. In addition, we studied patients with recurrent carotid stenosis, those with contralateral high-grade
85 Table 2 Indications for Arteriography (Schneider et al 2005) Indications
%
Define carotid occlusive disease Define etiology of hemorrhage Intracranial aneurysm/AVM Evaluate vasospasm Trauma Tumor Vasculitis Congenital/anatomic anomaly Venous occlusive disease
86 3 2 <1 5 2 1 <1 <1
Abbreviation: AVM, arteriovenous malformation. Reprinted with permission from The Society for Vascular Surgery.16
(⬎80%) ICA stenosis, and those with symptomatic highgrade (⬎80%) ICA stenosis at the discretion of the attending vascular surgeon. In addition, patients being considered for carotid angioplasty and stenting may benefit from a complete diagnostic study (as a separate procedure) prior to CAS to assist in decision making and treatment planning, especially in those just embarking on a program of CAS. Schneider et al16 have recently reported their experience with carotid angiography in 503 patients over a period of 45 months from three separate institutions. The majority of their patients were symptomatic (TIA, 35%; prior stroke, 24%; vertebrobasilar ischemia/nonspecific symptoms, 7%), while only 34% underwent angiography for asymptomatic disease. Indications for angiography are listed in Table 2. The indications and results of these procedures were compared with quality standards for the performance of carotid angiography from a cooperative study of the American Society of Interventional and Therapeutic Neuroradiology, the American Society of Neuroradiology, and the Society of Cardiovascular and Interventional Radiology.17 Thresholds that should be met or exceeded by physicians performing diagnostic carotid angiography include appropriateness of indication (Table 3) in 99% and a success rate of 98%. Acceptable levels of neurologic and nonneurologic complications include reversible neurologic defecit, TIA, and reversible stroke (2.5%), permanent neurologic deficit (1%), renal failure (0.2%), access site arterial occlusion (0.2%), pseudoaneurysm/arteriovenous fistula (0.2%), and hemorrhage requiring transfusion/evacuation (0.5%) are defined. The rate of all major complications should not exceed 2.0%. In both cited studies performed and reported on by vascular surgeons,1,16 these thresholds for indication and complications are met. As catheter-based therapy becomes increasingly integrated into vascular surgery practice,18 vascular surgeons will be required to incorporate carotid arteriography into their skill sets. We have favored relatively restrictive criteria for its use, while others have proposed a more liberal approach. Given the high-profile nature of diagnostic and therapeutic procedures in this particular circulatory bed, a strong foundation of endovascular skills in other territories is mandatory. In addition, surgeons need to be well-versed in selective cannulation of the brachiocephalic trunks and diagnostic arteriography prior to delving into the arena of carotid intervention.
E.M. Langan, B.H. Gray, and T.M. Sullivan
86 Table 3 Appropriate Indications for Adult Diagnostic Neuroangiography17 1. Define presence or extent of vascular occlusive disease and thromboembolic phenomenon 2. Define etiology of hemorrhage (subarachnoid, intraventricular, parenchymal, and craniofacial) 3. Define presence, location, anatomy of intracranial aneurysms and vascular malformations 4. Evaluate vasospasm related to subarachnoid hemorrhage 5. Define presence or extent of trauma to cervicocerebral vessels (eg, dissection, pseudoaneurysm) 6. Define vascular supply to tumors 7. Define presence or extent of vasculitis (infectious, inflammatory, or drug-induced) 8. Diagnose and/or define congenital or anatomic anomaly 9. Define presence of venous occlusive disease 10. Outline vascular anatomy for planning and determining the effect of therapeutic measures 11. Perform physiologic testing of brain function
4.
5.
6. 7.
8.
9.
10.
11.
Again, proper patient selection and meticulous attention to detail are paramount. 12.
Conclusions Diagnostic carotid arteriography via selective brachiocephalic catheterization can be safely performed by vascular surgeons with expertise in peripheral endovascular procedures. Selective arteriography of the carotid arteries remains an important adjunct in the evaluation of patients with carotid disease. Adherence to published guidelines regarding indications and results is mandatory. Selective brachiocephalic catheterization is an important skill set for the vascular surgeon to master as a segue to carotid angioplasty and stenting.
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References 1. Sullivan TM, Patel A, Langan EM et al: Can carotid angiography be performed by vascular surgeons? A critical evaluation of indications, technique, and results. Ann Vasc Surg 18:710-713, 2004 2. Ricotta JJ, Holen J, Schenk E, et al: Is routine angiography necessary prior to carotid endarterectomy? J Vasc Surg 1:96-102, 1984 3. Loftus IM, McCarthy MJ, Pau H, et al: Carotid endarterectomy without
17.
18.
angiography does not compromise operative outcome. Eur J Vasc Endovasc Surg 16:489-493, 1998 Logason K, Karacagil S, Hardemark HG, et al: Carotid endarterectomy solely based on duplex scan findings. Vasc Endovasc Surg 36:9-15, 2002 Kasper GC, Lohr JM, Welling RE: Clinical benefit of carotid endarterectomy based on duplex ultrasonography. Vasc Endovasc Surg 37:323327, 2003 Sandison AJ, Wood CH, Padayachee TS, et al: Cost-effective carotid endarterectomy. Br J Surg 87:323-327, 2000 Spadone DP, Barkmeier LD, Hodgson KJ, et al: Contralateral internal carotid artery stenosis or occlusion: Pitfall of correct ipsilateral classification.—A study performed with color-flow imaging. J Vasc Surg 11: 642-649, 1990 AbuRahma AF, Richmond BK, Robinson PA, et al: Effect of contralateral severe stenosis or carotid occlusion on duplex criteria of ipsilateral stenoses: Comparative study on various duplex parameters. J Vasc Surg 22:751-762, 1995 Fujatani RM, Mills JL, Wang LM, Taylor SM: The effect of unilateral internal carotid arterial occlusion upon contralateral duplex study: Criteria for accurate interpretation. J Vasc Surg 16:459-468, 1992 Johnston DC, Eastwood JD, Nguyen T, Goldstein LB: Contrast-enhanced magnetic resonance angiography of carotid arteries: Utility in routine clinical practice. Stroke 33:2834-2838, 2002 Sameshima T, Futami S, Morita Y, et al: Clinical usefulness of and problems with three-dimensional CT angiography for the evaluation of arteriosclerotic stenosis of the carotid artery: Comparison with conventional angiography, MRA and ultrasound sonography. Surg Neurol 51:301-308, 1999 De Monti M, Ghilardi G, Caverni L, et al: Multidetector helical angio CT oblique reconstructions orthogonal to internal carotid artery for preoperative evaluation of stenosis. A perspective study of comparison with US color Doppler, digital subtraction angiography and intraoperative data. Minerva Cardioangiol 51:373-385, 2003 Erdoes LS, Marek JM, Mills JL, et al: The relative contributions of carotid duplex scanning, magnetic resonance angiography, and cerebral arteriography to clinical decision making: A prospective study in patients with carotid occlusive disease. J Vasc Surg 23:950-956, 1996 Executive Committee for the Asymptomatic Carotid Atherosclerosis Study: Endarterectomy for asymptomatic carotid artery stenosis. JAMA 273:1421-1428, 1995 Dawson DL, Zierler RE, Strandness DE, et al: The role of duplex scanning and arteriography before carotid endarterectomy: A prospective study. J Vasc Surg 18:673-683, 1993 Schneider PA, Silva MB, Bohannon WT, et al: Safety and efficacy of carotid angiography in vascular surgery practice. J Vasc Surg 41:238245, 2005 Cooperative study between ASITN, ASNR, and SCVIR: Quality improvement guidelines for adult diagnostic neuroangiography. Am J Neuroradiol 21:146-150, 2000 Sullivan TM, Taylor SM, Blackhurst DW, et al. Has endovascular surgery reduced the number of open vascular operations performed by an established surgical practice? J Vasc Surg 36:514-519, 2002