Duplex Ultrasound Mapping Protocol for Placement of Cardiopulmonary Bypass Cannulae for Robotic Mitral Valve Surgery

Abstract

Background Duplex ultrasound is a noninvasive, low-cost modality for evaluation of lower-extremity arteries and veins. We developed a protocol to evaluate the lower-extremity vasculature for patients who may undergo robotic mitral valve repair that requires placement of cardiopulmonary bypass cannulae in the common femoral artery and vein. We report our early experience with this mapping protocol. Method The protocol includes imaging of bilateral distal external iliac, common femoral, and femoral arteries and veins. Documentation includes minimal vessel diameter at each segment, the presence of stenotic or calcified plaque, and lumen diameter in the presence of protruding atheroma. Bilateral ankle-brachial indices are recorded. Results During the period October 9, 2009 to February 4, 2010, we performed 100 mapping protocol studies. Mean patient age was 57.2 years (range, 20–84 years), and 65% were men. The presence of vascular calcification was noted in 34% of patients. No patient had hemodynamically significant arterial stenosis or deep-vein thrombosis. Mean lower-limb ankle-brachial indices were 1.13 (range, 0.90–1.34). Intraoperative common femoral artery and/or common femoral vein diameter measurements were available for 15 patients who underwent robotic surgery. Among this sample, there was no statistically significant difference between ultrasound mapping measurements and intraoperative diameter measurements (common femoral artery: 0.99 cm ultrasound versus 1.03 cm intraoperatively, p = 0.29; common femoral vein: 1.06 cm ultrasound versus 1.09 cm intraoperatively, p = 0.82). Conclusion Our surgical colleagues have found these mapping procedures to be useful in selecting candidates for robotic surgery and in planning the procedure. Duplex ultrasound is a useful and accurate tool for evaluating patients for robotic cardiac surgery requiring femoral cannulation for cardiopulmonary bypass.