Peripheral Arterial Assessment: word of caution
Marshall & Flyvbjerg's clinical review (reference 1) completely
overlooks the fallacy and gives some contradictory information about
measuring the ankle-brachial pressure ratio (ABPR) in diabetics. It also
portrays an over-simplistic and unrealistic picture of a vexed issue of
dealing with peripheral arterial disease assessment in diabetics.
Firstly, 10-15% diabetics may have falsely elevated ABPR (reference
2)due to early calcification of the tunica media that renders the arteries
incompressible. One should not solely rely on this as an objective
assessment criteria. To overcome this problem pole-test (reference 3)is
more accurate. The arteries of the foot and toes are relatively spared in
diabetes. Therefore other tests like toe-pressure index, analysis of
doppler wave-form, pulse volume analysis and transcutaneous oxygen
measurements are far better but these can rarely be performed outside the
Secondly, for practical reasons if one wants to measure ABPR in
diabetics to assess arterial insufficiency or ischaemia, it should be
measured at peroneal artery rather than posterior tibial or dorsalis pedis
as mentioned in the clinical review. Peroneal artery in the leg is also
relatively spared from calcification and thus offers the best available
option (reference 3).
Thirdly, the review very briefly mentions about identifying the four
"classic" risk factors for developing diabetic foot problem but it is
often not that straight forward. These so-called "classic" factors often
blur the picture rather than making it more obvious.Whereas symptoms like
pain in foot or leg while resting or during sleep indicate critical
ischaemia in non-diabetics, diabetics have a higher incidence of nocturnal
muscle cramping which is not due to arterial insufficiency at all.
Assessment of pulse in oedematous, ulcerated foot may not be possible and
infection of foot ulcers due to neuropathy often masks the sutle signs of
arterial insufficiency e.g. skin colour changes associated with elevation
or lowering of the foot.
I agree with the authors' very brief remark that early referral to a
specialist multidisciplinary team is essential in order to reduce
complications like amputation. We need to look at the interplay of all
contributing factors carefully rather than simply relying on just one
magic test or pressure-readings in diabetics.
1.Marshall SM, Flyvbjerg A. Prevention and early detection of
vascular complications of diabetes (clinical review).BMJ 2006;333:475-
2.Weitz JI,Byrne J, Clagett GP, et al. Diagnosis and treatment of
chronic arterial insufficiency of lower extremities: a critical review.
3. Boulton AJM, Connor H,Cavanagh PR (Editors). The foot in diabetes
(3rd edition, 219). John Wiley & Sons Ltd.
4. Raines JK, Darling RG, Buth J, et al. Vascular laboratory criteria
for the management of peripheral vascular disease of the lower
extremities. Surgery 1976;79:21.
Competing interests: No competing interests