Author's reply
Sir
McShane and Chant are generous in their comments on our paper and we are grateful. Many units in both Europe and the USA have used Duplex for graft follow-up with varying success. Firstly, the technique can be time consuming and we agree that technical developments have improved this, but it remains imperative to assess the whole graft rather than sampling it, as velocities and flow may return to normal downstream from a stenosis. Secondly, as they point out, the distal anastomosis can be difficult to assess. We sought to overcome this problem by assessing the graft just proximal to the anastomosis and the popliteal artery just distal to it. This problem only arises in femoropopliteal grafts as anastomoses to crural vessels at the level of the ankle are easier to assess. However, in these patients the small distal vessels may be difficult to pick up.
Many aspects in the postoperative use of Duplex scanning were not mentioned in our paper, and we apologize if this confused the reader. The single purpose of our communication was to publish a reproducible formula that should simplify our objective assessment~particularly in the assessment of early, non-haemodynamically significant stenoses.