That makes perfect sense Chrissie,
It explains why they are easy to scan when I see them weeks out months after the surgery, and it makes sense why you can not see into the graft in the immediate post op setting,
It also makes sense why you thought it was a gas issue.
Thanks so much for enlightening me and everyone else who is enjoying the forum about this.
It is a great trap for young players and we now know to delay assessment of the graft itself for a while after placement but we also know we can infer graft latency or failure by looking at the waveforms immediately proximal and distal to the graft on the native vessels.
So good !
Steve.