Intraoperative high resolution duplex imaging during carotid endarterectomy: which abnormalities require surgical correction?

OBJECTIVES: This study evaluates high resolution, duplex ultrasound imaging for quality control of carotid endarterectomy in order to determine which technical factors were linked to residual stenosis and to define duplex criteria for re-exploration.

DESIGN, MATERIAL AND METHODS: A consecutive series of 100 patients undergoing carotid endarterectomy were evaluated. Duplex imaging was performed prior to wound closure and repeated at 6-8 weeks postoperatively. Stenoses were classified as non-significant, moderate or severe based on duplex criteria. Intimal flaps, shelves, kinks, clamp damage and fronds were identified by ultrasound imaging.

RESULTS: Five moderate stenoses were noted in the proximal endarterectomy site (PES), and at follow-up three had resolved. Adherent fronds were detected in 83% of vessels and resolved in all but three cases. At the distal endarterectomy site there were 10 severe and 12 moderate stenoses. Intimal flaps were associated with an increased incidence of residual stenosis (p = 0.010).

CONCLUSIONS: We conclude that severe stenoses with an intimal flap should be corrected immediately. Further data is required to establish the significance of kinks. Residual intimal flaps in the PES appear to remodel. The role of completion duplex may lie in the modification of surgical technique to eradicate anatomical and haemodynamic imperfections.