Carotid

Caratid Endarterectomy

Intraoperative Blood Flow Measurement - PDF

Courtesy of Ian Gordon, MD, PhD, Assistant Professor, Department of Surgery, University of California, Irvine

Surgical Approach

No special adjustment in surgical technique is necessary for measurement of blood flow during carotid surgery. The sites on the carotid arteries skeletonized by dissection for vascular clamp placement are identical as those employed for probe placement. A 10 mm probe (sometimes an 8 mm probe is used) is employed for the distal common carotid artery and a 6 mm probe for the origin of the internal and external carotid arteries.

The probe on the external carotid is placed just distal to the origin of the superior thyroid artery. We perform the pre-endarterectomy flow measurements immediately after administration of systemic heparin, and the measurement of all three arteries only requires a few minutes.

After the first measurement, vascular clamps are placed and the endarterectomy performed. We shunt all our patients with a large Javid shunt and place a clamp-type probe on the shunt to ensure that any interruption of shunt flow is detected.

After finishing the endarterectomy, removal of all clamps, and establishing hemostasis, a repeat flow measurement is performed. Occasionally, low flow or a turbulent flow waveform is detected indicating the presence of a significant stenosis which requires immediate revision. As a consequence, we try not to reverse heparin with protamine until completion of the flow measurements.

Conduits: Recommended probe size

common carotid artery: 8 or 10 mm
external carotid artery: 6 mm
internal carotid artery: 6 mm

References

Gordon, I.L., Stemmer, E.A., Wilson, S.E., "Redistribution of Blood Flow after Carotid Endarterectomy," Journal of Vascular Surgery, Vol. 22, p. 349-360, 1995. (593AH)

Gordon, I.L., Weil, J., Williams, R.A., Wilson, S.E. "Intraoperative Measurement of Javid Shunt Flow with Transit-Time Ultrasound," Annals of Vascular Surgery, 8(6) 571-577, 1994. (371AH)

Gordon, I.L., Stemmer, E.A., Williams, R.A., Arafi, M., Wilson, S.E. "Changes in Internal Carotid Blood Flow after Carotid Endarterectomy Correlate with Preoperative Stenosis," The American Journal of Surgery, Vol. 168, p. 27-130, 1994.(364AH)

Gordon, I.L., Goldstein, L.J., Ceraldi, C., Weir, P., Tobis, J., Stemmer, E., "Hemodynamic Effects of Serial Stenoses in An Arterial Model," American College of Surgeons, Surgical Forum, XLII, p. 315-319, 1991. (192AH)