Saphenous vein valve assessment utilizing upright CT to potentially improve graft assessment for bypass surgery.

ABSTRACT

Saphenous veins (SVs) are frequently employed as bypass grafts. The SV graft failure is predominantly seen at the valve site. Avoiding valves during vein harvest would help reduce graft failure. We endeavored to detect SV valves, tributaries, and vessel size employing upright computed tomography (CT) for the raw cadaver venous samples and in healthy volunteers. Five cadaver legs were scanned. Anatomical analysis showed 3.0 (IQR 2.0-3.0) valves and 13.50 (IQR 10.00-16.25) tributaries. The upright CT completely detected, compared to 2.0 (IQR 1.5-2.5, p = 0.06) valves and 9.5 (IQR 7.5-13.0, p = 0.13) tributaries by supine CT. From a total of 190 volunteers, 138 (men75, women63) were included. The number of valves from the SF junction to 35 cm were significantly higher in upright CT than in supine CT bilaterally [upright vs. supine, Right 4 (IQR 3-5) vs. 2 (IQR1-2), p < 0.0001, Left 4 (IQR 3-5) vs. 2 (IQR 1-2), p < 0.0001]. The number of tributaries and vessel areas per leg were also higher for upright compared with supine CT. Upright CT enables non-invasive detection of SV valves, tributaries, and vessel size. Although not tested here, it is expected that upright CT may potentially improve graft assessment for bypass surgery.