Selective Imaging Best For Carotid Surgery?

By Mitchel L. Zoler, MD

PHILADELPHIA -- Routine, intraoperative imaging of the carotid artery during endarterectomy did not improve patient outcomes in a review of over 9,000 patients.

Given the time and money involved and its questionable clinical value, routine imaging should be abandoned in favor of selective imaging for clinical indications, Dr. Caron B. Rockman said at the Vascular Annual Meeting.

The data also showed that routine, intraoperative imaging was done more often by vascular surgeons compared with other surgeons, and by higher-volume operators.

The analysis used Medicare data from all 481 surgeons who performed carotid endarterectomy in New York State during January 1998-June 1999. The 9,306 surgeries were done at 158 hospitals.

No routine imaging was most common, in almost 6,000 patients (64%). Surgery for the remaining patients included some routine, perioperative imaging, with continuous-wave Doppler most common (over 2,300 patients or 25%). Duplex scanning was used in 585 (6%), and fewer patients had with either arteriography alone, or some combination of these three imaging modes.

The perioperative stroke rate was 3.1% in patients who weren't routinely imaged, and 3.6% in those who had any type of imaging, a nonsignificant difference. The rate of death and stroke also was similar: 4.3% with routine imaging, and 3.8% without, said Dr. Rockman, a vascular surgeon at New York University. Routine imaging had no impact on perioperative outcomes when the analysis only included patients symptomatic at the time of surgery.

Slightly more than half of the surgeries were by vascular surgeons. In this subgroup, routine imaging was used for 43% of patients, compared with a 27% rate when surgery was done by another type of surgeon, a significant difference.

Another analysis divided patients based on the volume of endarterectomy cases. The top 40% of surgeons by volume were defined as high-volume surgeons (who performed at least 57 endarterectomies during the 18 months), while the remaining 60% were defined as low-volume surgeons. High- volume surgeons used routine imaging in 45% of their cases, compared with a 30% rate by the low-volume surgeons, a significant difference.