EVIDENCE FOR A "LEARNING CURVE" EFFECT IN OUTCOMES FOLLOWING CAROTID STENTING
G. New*1, S.S. Iver1, J.J. Vitek1, R. Bonomo1, E. Lawrence1, M Oetgen1, J.W. Moses1, V. Yates2, L. Dean2, G.S. Roubin1.
1Lenox Hill Hospital, New York, 2University of Alabama, Birmingham, Alabama, USA.
Carotid stenting (CS) is a relatively new technique used for the treatment of carotid stenosis. The aim of this study was to demonstrate whether changes in technique, equipment and patient selection over the past 4 years have influenced outcomes in patients undergoing this procedure. Between September 1994 and January 1999, 449 patients (487 vessels) with symptomatic and asymptomatic carotid stenoses were prospectively studied to determine the safety and efficacy of CS. To investigate the influence of a "learning curve" effect, we grouped patients into quartiles. Technical changes over this time included; staged procedures for bilateral stenoses and coincident coronary interventions, pre-dilation using small coronary balloons, use of self-expandable stents and judicious post-dilation, and improvement in antiplatelet and anticoagulation regimens. Patient exclusion criteria extended to; severely tortuous, calcified and atherosclerotic origins of the great vessels, total occlusion of the internal carotid artery and large baseline neurological deficits.
Table 1. In-hospital and 30 day clinical outcomes
|
9/94-9/95 |
9/95-9/96 |
9/96-9/97 |
9/97-12/98 |
|
|
Patients |
89 |
|||
|
Vessels |
97 |
|||
|
Major Stroke |
1 |
1 |
1 |
0 |
|
Minor Stroke |
7(7.2%) |
8(6.7%) |
6(4.4%) |
3(2.2%) |
|
Neurological Death |
0 |
0 |
3* |
0 |
*2 occlusions, 1 carotid rupture.
Conclusion: In the last 128 consecutive patients there have been no major strokes, no deaths and a 2.2% incidence of minor non-disabling strokes. Based on AHA guidelines for CEA performance standards, experienced operators able to achieve comparable low complication rates could offer CS as an alternative to carotid endarterectomy.
