Vascular: Peripheral Vascular Disease

Question 1

Basic pathophysiology of atherosclerotic process

Answer 1

Hardening of arteries with fatty buildup (chronic inflammatory condition).
Fatty streak formation -> plaque progression -> plaque disruption.
Plaque has thrombogenic lipid cord underlying a protective fibrous cap. Progression of plaque leads to restriction in lumen size and impediment of blood flow.
Plaque disruption caused by erosion with subsequent thrombosis that occludes the vessels locally. Get formation of emoli that travels downstream to occlude smaller vessels.

Question 2

What is claudication and what are the steps involved in conservative mgmt.

Answer 2

Claudication: leg pain during walking that is relieved by short rest. Caused by decreased blood flow to leg and change in metabolic function of skeletal muscle due to intermittent ischemia.

Conservative mgmt: best tx, 60-80% improvement. exercise therapy involves walking 30 min, 3x per week. Need to continue walking beyond when pain sets in. Stimulates development of collateral vessels.

Question 3

5 stages of claudication

Answer 3

1) non specific symptoms
2) intermittent claudication, reproducible over same distance, same location in leg and same amount of rest needed.
3) rest pain and night pain
4) tissue loss -> ulceration and gangrene.
5) Critical limb ischemia: pain most commonly over forefoot, wakes person from sleep, often relieved by hanging foot off bed.

Question 4

RF claudication

Answer 4

smoking, DM, HTN, hyperlipidemia, famHx, obesity, sedentary lifestyle, CAD/CVD.

Question 5

PEx for claudicants

Answer 5

Look for absent pulses, listen for bruits.
Poor perfusion: hair loss, hypertrophic nails, atrophic muscles, skin ulcerations/infection, slow cap refill, prolonged pallor with elevation and redness with gravity.
Ulceration: common on lateral ankle and foot, pale, no granulation tissue.
CVD, CAD, impotence, splanchnic ischemia.

Question 6

Explain ABIs

Answer 6

Correlates with severity of arterial ischemia.
Take highest brachial and highest ankle prsesure for each side. Measure at rest and exercise.
Decreased accuracy if CHF, DM.

Interpretation: 
Normal: 1
Intermittent claudication: 0.6 - 0.8
Ischemic rest pain: 0.3 - 0.5 
Impending tissue necrosis: 0.1 0.2

Question 7

DDx of intermittent claudication

Answer 7

Vascular: atherosclerotic disease, vasculitis, DM neuropathy, venous disease, popliteal entrapment syndrome.

Neurologic: neurospinal disease, reflex sympathetic dystrophy.

MSK: OA, RA, remote trauma.

Question 8

Appropriate investigations for claudication

Answer 8

Fasting metabolic profile, ABI, duplex US arteries, CTA, diagnostic ateriography (invasive– better if you need to visualize tibial arteries).

Question 9

Tx options for PVD

Answer 9

Conservative: RF reduction, exercise program, foot care.

Medical: antiplatelet tx, statins, B blockers, ACEi, PDEi (e.g. cilostazol -> arterial dilation to increase blood supply to legs), pentoxifylline (trental- improves flow of blood by decreasing viscosity).

Surgical: consider if severe lifestyle impairment, vocational impairment, critical ischemia. Can do endovascular repair (angioplasty, stents), endarterectomy (removal of plaque and repair with patch), bypass graft surgery.