Saphenous Vein Valves Assessment Utilizing Upright CT. -Potentially Improve the Graft Assessment for Bypass Surgery-

The saphenous veins (SV) 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 CT for the raw cadaver venous samples and in healthy volunteers.Five cadaver legs were scanned. The 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 190 volunteers, 138 (men:75, women:63) 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 (IQR:1-2), p<0.0001, Left: 4 (IQR: 3-5) vs. 2 (IQR: 1-2), p <0.0001]. The number of tributaries and vessel area was also higher for upright compared with supine CT.Upright CT enable detection of SV valves, tributaries, and vessel size non-invasively. Although not tested here, it is expected that upright CT might potentially improve the graft assessment for bypass surgery.