Assisted venous drainage on cardiopulmonary bypass for minimally invasive aortic valve replacement: Is it necessary, useful or desirable?

Abstract

Assisted venous drainage (AVD) is considered an essential component of the cardiopulmonary bypass (CPB) circuit for minimal access aortic valve replacement (mAVR). The rationaleynecessity for AVD in every patient has not been fully elucidated. Data from consecutive patients undergoing isolated first-time mAVR by a single surgeon from March 2006 to October 2008 was prospectively collected. All cases were cannulated centrally. Venous drainage was by a three-stage cannula (Medtronic MC2X) via the right atrial appendage. AVD was utilised intraoperatively at the discretion of the perfusionist andyor surgeon to maintain the required flow rate. Pre- and perioperative data were compared between the two groups. Fifty-seven patients underwent mAVR. Twenty-nine did not require assistance (AVD-), 28 did (AVD+). There were no significant differences between the two groups' age, sex distribution, body mass index and risk stratification data. Patients who required AVD had significantly higher body surface areas (BSAs) [1.93 m2 (1.56-2.46) vs. 1.79 m2 (1.41-2.26), P=0.03] and consequent higher CPB flow required [4.62 l/min (3.74-5.90) vs. 4.29 l/min (3.38-5.42), P=0.03]. Patients who required AVD tended to have longer ischaemic times [79.5 min (48-135) vs. 69 min (47-126), P=0.06]. AVD during mAVR is not necessary in every patient. We found it to be necessary in patients with higher BSA (consequently requiring a higher flow rate on CPB). © 2010 Published by European Association for Cardio-Thoracic Surgery. All rights reserved.