The value of a carotid duplex surveillance program for stroke prevention

Area of Science:

• Vascular Surgery
• Diagnostic Imaging
• Stroke Prevention

Background:

• Controversy exists regarding the natural history and surveillance of asymptomatic carotid stenosis.
• The utility and cost-effectiveness of duplex ultrasonography (DU) surveillance after carotid endarterectomy (CEA) remain debated.
• Current guidelines lack consensus on optimal DU surveillance intervals for carotid disease.

Purpose of the Study:

• To evaluate the clinical management changes resulting from DU surveillance for asymptomatic or post-CEA carotid stenosis.
• To determine the number of strokes prevented by DU surveillance programs.
• To calculate the cost-effectiveness of DU surveillance per stroke prevented.

Main Methods:

• A 9-year vascular surgical database (2000-2008) was reviewed for patients in a carotid DU surveillance program.
• Data on DU scans, CEAs, and reimbursement were collected through March 2010.
• The Asymptomatic Carotid Atherosclerosis Study results were used to estimate strokes prevented by CEA.

Main Results:

• Over 11,500 DU scans were performed on 3,003 patients; 7.5% underwent CEA for asymptomatic stenosis.
• The DU surveillance program prevented an estimated 13 strokes, with 871 scans per stroke prevented.
• The total program cost was ~$3.8 million, averaging $290,000 per stroke prevented.

Conclusions:

• Carotid DU surveillance programs are costly and inefficient for stroke prevention.
• A reappraisal of the "value" of routine carotid DU surveillance is necessary.
• Routine post-CEA surveillance and extensive asymptomatic disease surveillance should be limited.