This study was designed to investigate the retrograde arterial pressur
es in the distal ends of the superior thyroid (n = 20) and facial arte
ries (n = 8). These pressures were compared with mean systemic arteria
l pressure (n = 20) as well as retrograde pressure in the radial arter
y (n = 8). The mean retrograde arterial pressure in the radial artery
was 50 to 60 percent of normal arterial pressure. Similar pressures we
re recorded from the distal ends of both the superior thyroid and faci
al arteries. Because we know that the radial artery can support a skin
flap through retrograde or reverse flow (reverse radial forearm flap)
, it was concluded that both the superior thyroid and facial arteries
could also support flaps based on reverse flow. This has proved to be
the case clinically. In circumstances where pedicle geometry favors it
and in the presence of pulsatile flow from the distal ends of either
of these arteries, a retrograde anastomosis is now the practice of the
authors in selected cases.