Lumbar sympathectomy has a controversial place in the management of se
vere limb ischemia for limb preservation, In a consecutive clinical se
ries laser Doppler (LD) blood flow was measured at the distal limit of
an anterior below knee skin flap in 21 patients. Amputation level was
selected by clinical judgement. Mean LD value in 15 patients who had
primary BK healing was 42V (range 20-85) compared to 11V (9-20) in six
patients who proceeded to AK amputation (p<0.001) establishing 20V as
a critical value for BK healing. To examine the effect of chemical sy
mpathectomy 21 further patients with severe ischemia had LD measuremen
ts at the same BK site before and one week after chemical sympathectom
y. LD values rose significantly from 26V (10-75) to 50V (10-100), (p<0
.001). In particular seven patients had initial LD levels below 20V an
d in five chemical sympathectomy produced elevation to levels commensu
rate with BK healing. We conclude that chemical sympathectomy can impr
ove below knee skin blood flow and may enhance primary wound healing.