Carotid endarterectomy without angiography: a prospective randomised pilot study

[Internal carotid artery occlusion or subocclusion--contemporary diagnostic challenges: case report]

INTRODUCTION

Measurement of vessel stenosis using ultrasonography or magnetic resonance is still the principal method for determining the severity of carotid atherosclerosis and need for endarterectomy.

CASE OUTLINE

A 56-year-old male was admitted to the Cardiovascular Institute "Dedinje" due to a clinically asymptomatic restenosis of the operated left internal carotid artery (ICA). Angiography and magnetic resonance angiography (MRA) in previous hospitalization had revealed occluded right ICA. However, routine duplex ultrasonography revealed a high-grade restenosis (85%) of the left ICA and subocclusion of the right ICA by an ulcerated plaque (confirmed on repeated MRA).

CONCLUSION

Selective arteriography examination could misrepresent the degree of stenosis especially in patents with the ICA that seems to be occluded. MRA is considered the method of choice for identifying pseudo-occlusions of ICA.

National Stroke Association guidelines for the management of transient ischemic attacks

OBJECTIVE

Transient ischemic attacks are common and important harbingers of subsequent stroke. Management varies widely, and most published guidelines have not been updated in several years. We sought to create comprehensive, unbiased, evidence-based guidelines for the management of patients with transient ischemic attacks.

METHODS

Fifteen expert panelists were selected based on objective criteria, using publication metrics that predicted nomination by practitioners in the field. Prior published guidelines were identified through systematic review, and recommendations derived from them were rated independently for quality by the experts. Highest quality recommendations were selected and subsequently edited by the panelists using a modified Delphi approach with multiple iterations of questionnaires to reach consensus on new changes. Experts were provided systematic reviews of recent clinical studies and were asked to justify wording changes based on new evidence and to rate the final recommendations based on level of evidence and quality. No expert was allowed to contribute to recommendations on a topic for which there could be any perception of a conflict of interest.

RESULTS

Of 257 guidelines documents identified by systematic review, 13 documents containing 137 recommendations met all entry criteria. Six iterations of questionnaires were required to reach consensus on wording of 53 final recommendations. Final recommendations covered initial management, evaluation, medical treatment, surgical treatment, and risk factor management.

INTERPRETATION

The final recommendations on the care of patients with transient ischemic attacks emphasize the importance of urgent evaluation and treatment. The novel approach used to develop these guidelines is feasible, allows for rapid updating, and may reduce bias.

Is contralateral carotid artery occlusion a risk factor for carotid endarterectomy?

Occlusion of the contralateral internal carotid artery (ICA) is considered to have a significant impact on the outcome of carotid endarterectomy (CEA). The purpose of this study was to review one center's experience concerning CEA opposite an occluded ICA, to see whether results differed from those obtained in patients with patent contralateral ICA in terms of relevant neurologic complication rate (RNCR, fatal + disabling stroke), stroke-free rate, and survival rate. From January 1997 to December 2002, 1,381 patients underwent a total of 1,445 CEAs at the Department of Vascular Surgery of Padua University. Patients were divided into two groups: group A included 144 patients with occlusion of the contralateral ICA and group B consisted of 1,237 patients with a patent contralateral ICA. There was no postoperative mortality in patients of group A, while in group B, two patients died as a result of myocardial infarction and cardiac failure and one died as a direct result of perioperative stroke. Postoperative disabling strokes occurred in one (0.7%) patient in group A and 10 (0.8%) patients in group B (p > 0.5). At 72 months, there were no statistical differences between the two groups in terms of RNCR, stroke-free rate, and late death. Our results show that contralateral carotid occlusion does not reduce the safety of CEA. The efficacy in terms of RNCR, stroke-free rate, and late survival is no different in patients with contralateral carotid occlusion.

The diagnostic accuracy of computed tomography angiography for traumatic or atherosclerotic lesions of the carotid and vertebral arteries: a systematic review

INTRODUCTION

Helical computed tomography angiography (CTA) has become an established technique for evaluating atherosclerosis of the cerebrovascular arteries. However, the role of CTA in penetrating and blunt trauma to the carotid and vertebral arteries is not well defined. We conducted a systematic literature review to determine the diagnostic accuracy of CTA for atherosclerotic, penetrating and blunt lesions in the carotid and vertebral arteries.

METHODS

We searched MEDLINE and EMBASE databases to identify studies evaluating the diagnostic accuracy of CTA of the carotid and vertebral arteries published between January 1, 1992 and December 31, 2002. Two reviewers independently assessed abstracts and full text to determine study eligibility. Information on methodological quality, imaging technique and diagnostic accuracy was abstracted from all eligible studies by three independent reviewers. We pooled sensitivity and specificity data from diagnostic accuracy studies of high methodological quality.

RESULTS

Forty-three articles met the inclusion criteria and were included in the review. Thirty studies examined atherosclerotic disease, two blunt trauma, two penetrating trauma and nine examined patients with other pathology. Pooled data from 15 higher quality studies demonstrated that CTA had a sensitivity of 95% (91-97% CI) for detecting severe (>70%) atherosclerotic stenosis of the carotid artery. The specificity of CTA for severe stenosis was also high 98% (96-99% CI). CTA remained a sensitive technique (95%; 93-97% CI) when the criterion for a positive result is relaxed to moderate or greater (>30%) stenosis. Two studies raised concerns about the use of CTA in the blunt trauma setting, suggesting that CTA may not be sensitive for detecting small intimal injuries, although both of these studies used older technologies for either obtaining or viewing images. Conversely, two penetrating trauma studies concluded that the sensitivity of CTA was high.

CONCLUSIONS

Our findings demonstrate that CTA is both a sensitive and specific imaging technique for identifying severe atherosclerotic stenosis and occlusion of the carotid arteries. However, there is currently not enough high quality evidence to accurately estimate the sensitivity and specificity of CTA in the setting of blunt or penetrating trauma.

Carotid endarterectomy then and now: outcome and cost-effectiveness of modern practice

BACKGROUND

During the past decade, our practice of performing carotid endarterectomy (CEA) has changed dramatically, most notably by an abrupt shift from routine to selective preoperative angiography, reliance on defined care plans with full-time nurse practitioner oversight, and increasing reliance on eversion endarterectomy and cervical block anesthesia. This study was designed to determine whether these shifts in policy have been associated with lower costs without sacrificing clinical outcome.

METHODS

All patients undergoing CEA from July 1993 to December 2000 were identified, and inpatient and outpatient charts were reviewed. Cost data were obtained from the central hospital accounting system and converted to 2001 dollars. Thirty-day outcomes and costs were quantified each year and compared between each of 2 temporally well-defined groups: those undergoing "routine" versus "selective" angiography and those cared for before and after defined patient care protocols were instituted.

RESULTS

A total of 1168 CEAs were analyzed. Thirty-day combined stroke and death rate was 3.1%, and no trends or significant differences over time were seen. From 1993 to 2000 the cost of CEA fell from $9302 to $6216 (P<.0002), and length of stay was reduced 1 full day (P=.005). Institution of "selective" angiography was associated with an immediate cost savings of approximately $2000 per case (P<.0001), and nurse practitioner oversight along with institution of defined clinical protocols with a $530 (P<.05) decline in nonoperating room-related costs.

CONCLUSIONS

Changes in policy from routine to selective angiography, reliance on defined postoperative care pathways, eversion endarterectomy, and cervical block anesthesia have been associated with significant cost savings, with no compromise in clinical outcome at our institution.

The vascular laboratory in practice: a national survey in the Netherlands

OBJECTIVES

to overview Dutch vascular laboratory practice and specifically the variation in duplex criteria.

METHODS

a questionnaire was sent to all vascular laboratories in The Netherlands (n=140).

RESULTS

the response rate of the inquiry was 64% (n=89). There is no consensus on interpretation of outcome. In 22% of the clinics (n=20) a diagnostic angiography will be omitted when a percutaneous angioplasty is advised on account of duplex ultrasound. Only 5% (n=4) relies upon duplex ultrasound for operation without diagnostic angiography. In 44% (n=39) a PSV (peak systolic velocity) of 125 cm/s is used to identify a>70% or internal carotid artery stenosis. In 44% (n=39) a PSV of 210 cm/s and 10% (n=9) a PSV > or =150 cm/s is used. For grading a relevant stenosis in the femoro-politeal arteries a PSV ratio > or =2.5 is chosen in 75% (n=67). Criteria used for graft surveillance shows also a wide variation.

CONCLUSIONS

a commission for the accreditation of vascular laboratories should be established with the goal of creating standards and performing quality control.

Critical review of non- or minimally invasive methods (duplex ultrasonography, MR- and CT-angiography) for evaluating stenosis of the proximal internal carotid artery

OBJECTIVE

to assess the performance of non- or minimally invasive methods (duplex ultrasonography, MR- and CT-angiography) in measuring stenosis of the proximal internal carotid prior to endarterectomy without preoperative intra-arterial digital subtraction angiography (DSA).

METHODS

systematic review of the literature (five databases, 1990 to February 2001). The value of each imaging technique was studied through its reproducibility and its sensitivity/specificity compared to DSA.

RESULTS

sensitivity exceeded 80% and specificity 90% in over two-thirds of the methodologically sound studies, regardless of technique, although direct comparisons between results had to be avoided since the findings originated from different populations. The main drawback of duplex ultrasonography is its levels of reproducibility. In contrast, only a few studies have addressed the reproducibility of MR- and CT-angiography. When the results of duplex and MR-angiography agree, the combination use of these two techniques provides a better diagnosis than either technique taken alone.

CONCLUSIONS

all three techniques appear suitable for measuring stenosis of the proximal internal carotid when compared to DSA.

Carotid artery endarterectomy solely based on duplex scan findings

The purpose of this study was to review experience with carotid artery surgery based on findings obtained solely from duplex scanning with special regard to unexpected findings during surgery and the early outcome. From January 1993 through December 1999, 271 consecutive patients underwent 287 carotid endarterectomies (CEAs), 229 (80%) of which were performed solely based on duplex scan findings. During the study period 5,932 carotid artery duplex scans were performed in 4,466 patients. Of 589 patients with internal carotid artery (ICA) stenosis 70%, 246 underwent CEA compared to 25 of 156 with 50-69% ICA stenosis. The indications for CEA were transient ischemic attack (TIA) in 88 (30.7%), amaurosis fugax in 60 (20.9%), previous stroke in 91 (31.7%) and asymptomatic disease in 48 (16.7%) cases. There were no statistically significant differences between the groups operated on with and without preoperative angiography with respect to the indications for surgery, associated risk factors, or the degree of stenosis on the contralateral side. In patients undergoing surgery without angiography, there were no unexpected findings that influenced the performance of surgery, in all except 1. There were no significant differences in perioperative morbidity and mortality in patients undergoing surgery with and without conventional angiography. The combined mortality and major stroke rates were 3.4% and 2.2%, respectively. It is concluded that CEA can safely be performed without preoperative angiography in cases with conclusive duplex scan findings.

Magnetic resonance angiography and evaluation of cervical arteries

Multiple clinical trials have demonstrated the efficacy of endarterectomy in selected groups of patients based primarily on percent diameter stenosis. Although measurement of stenosis in the clinical trials was established by conventional angiography, there is considerable interest in noninvasive alternatives. Magnetic resonance angiography, performed using time-of-flight methods or with contrast enhancement, is one of several alternatives for noninvasive carotid evaluation. Screening examinations are routinely performed for carotid stenosis. Preoperative evaluations based on one or a combination of noninvasive tests have been proposed, although these proposals are the subject of ongoing controversy. Evaluation of the vertebral arteries is more difficult and less well studied: however, the increasing availability of therapies for posterior circulation atherosclerotic narrowing is resulting in increased interest in this problem.