Timing of Great Saphenous Vein Assessment Influences Vein Caliber Before CABG

Background: Preoperative ultrasonographic mapping of the great saphenous vein (GSV) is a valuable tool for improving assessment of vein caliber during surgical planning. However, current data are insufficient to establish clear standards for optimal anatomical evaluation. The aim of this study was to investigate the effect of anesthetic induction on GSV caliber in patients undergoing CABG. Methods: In this retrospective study, the diameter of the GSV was measured using ultrasonography at predefined anatomical landmarks during the pre- and post-induction periods in patients undergoing CABG, and the obtained values were compared. Results: A total of 59 patients were included. A significant increase in the GSV diameter was observed after anesthetic induction in all segments (all p < 0.001). The median diameters increased from 1.9 to 2.7 mm in the distal segment, from 1.6 to 2.4 mm in the mid segment, and from 2.3 to 3.4 mm in the proximal segment. The percentage change in diameter after anesthetic induction was comparable across all measured segments (p = 0.888). The pre-induction diameter was strongly and negatively correlated with the percentage diameter change in all segments (all p < 0.001), and this association remained significant after controlling for the post-induction diameter (all p < 0.001). Conclusions: In this study, the ultrasonographic assessment timing was found to significantly influence GSV caliber evaluation in patients undergoing CABG. Anesthetic induction was associated with a significant and consistent increase in saphenous vein diameter across all measured segments, suggesting that anesthetic status may influence ultrasound-based vein mapping and conduit assessment. Further prospective studies incorporating clinical outcome measures and conduit suitability assessment are needed to better clarify the clinical implications of these findings.