Editing Peripheral arterial disease (section)

== Classification of PAD: ==



''Note that Rutherford 6 has been defined as non-salvageable foot or necrosis extending anywhere proximal to the forefoot''

''Mild claudication = 300m''

''Moderate claudication = 200m''

''Severe claudication <100m''

=== Asymptomatic disease: ===

* May be asymptomatic because of mild disease, or adequate collateral supply, or limited activity for other reasons
* Risk of progression not well-defined, but about 7% deteriorate to IC over a 5-year period
* Manage by treating comorbidities and counselling risks

=== Claudication: ===

* ''Clinical syndrome - reproducible leg pain brought on by exercise and relieved by rest''
* Muscular impairment due to exercise-induced ischaemia, aka ''effort discomfort''.
** Most frequent presentation of lower extremity PAD
** Marker of systemic atherosclerosis
** Cramping/burning/aching muscular calf, thigh or buttock pain 
*** Occurs with walking
*** Resolves with rest (complete relief within 5-10 minutes), but not necessary to sit
*** Reproduced at same exertion level/distance
*** Can be associated with numbness, fatigue
** Can also occur in upper limb:
*** Secondary to stenosis of subclavian or axillary arteries
*** Differentiate from thoracic outlet syndrome
** Distribution is reflective of affected vessels:
*** Aortoiliac - buttock/thigh
*** Femoropopliteal - thigh
*** Tibial - calf
** Signs that claudication is not due to arterial pathology:
*** Pain does not limit exertion
*** Pain does not involve calves or other major muscles in the leg
*** Pain does not resolve within 10 minutes of rest
***
* Management:
**

* Prognosis:
** 21% of IC patients experience deterioration of limb status over 5 years
** Especially if comorbidities are not controlled and continue smoking


=== Chronic limb-threatening ischaemia (sometimes called severe limb ischaemia or chronic limb ischaemia) ===

* Either pain at rest or tissue loss (gangrene or non-healing ulceration). Typically, symptoms must be present for at least two weeks and be associated with an ankle pressure <50mmHg or a toe pressure <30mmHg to meet criteria.
** ''European consensus document defines CLI as:''
*** ''Persistent recurring ischaemic rest pain requiring opiates for at least two weeks and ankle systolic <50mm Hg OR toe systolic <30mm Hg; or''
*** ''Ulceration or gangrene of the foot or toes and ankle systolic <50mm Hg OR toe systolic <30mm Hg OR absent pedal pulses in diabetics''
** ''Wolfe and Wyatt divided it into:''
*** ''Subcritical ischaemia - rest pain and ankle pressure >40mm Hg''
*** ''Critical ischaemia - rest pain and tissue loss or ankle pressure <40mm Hg''
*** ''At one year, 27% of patients with subcritical ischaemia achieved limb survival without revascularisation, in contrast with only 5% in the critical ischaemia group. So, certain high-risk patients with subcritical ischaemia might be managed non-operatively, but anyone expected to live longer than 1-2 years will need either revascularisation or major limb amputation.''
* Severe impairment of limb perfusion, insufficient to maintain baseline tissue requirements
* High all-cause mortality due mostly to cardiac risks
* Multiple scoring systems available to define risk - use WIFi calculator to define one-year amputation risk (see below)
**


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