Peripheral Vascular Disease (PAD) Flashcards
What is acute arterial insufficiency?
Acute occlusion/rupture of a peripheral artery.
Where does acute arterial insufficiency generally affect?
Lower > upper extremity
Femoropopliteal > aortoiliac
What is the aetiology of acute arterial insufficiency?
Embolus, thrombus, trauma, idiopathic.
Less common: pro-coagulant state, thrombosed aneurysm, dissection, fibromuscular hyperplasia, arteritis, entrapment, advential cysts.
What are the features supportive of cardiac embolus causing acute arterial insufficiency?
-History of MI
What are the clinical features of acute arterial insufficiency?
- Pain: absent in 20%
- Pallor
- Paresthesia
- Paralysis/power loss
- Polar (cold)
- Pulselessness (not reliable)
How should acute arterial insufficiency be investigated?
CXR, ECG, arteriography
Mx acute arterial insufficiency?
- Immediate heparinization w/5000IU bolus (APTT >60s)
- Absent power/sensation: immediate revascularisation
- Present power/sensation: work up (inc angio)
- Progress to embolectomy/ thrombectomy/ amputation
- Commence warfarin d1 post op for 3/12
What are the complications of acute arterial insufficiency?
- Compartment syndrome (prolonged ischaemia)
- Renal failure and multi organ system failure due to ischaemic muscle
What is the aetiology of chronic arterial insufficiency?
Predominately atherosclerosis; usually affects lower extremities.
What are the RFx for chronic arterial insufficiency?
Major: smoking, DM, hyperhomocysteinemia
Minor: HTN, hyperlipidemia, FHx, obesity, sedentery life, male gender
What are the clinical features of chronic arterial insufficiency?
- Claudication
- Pulses may be absent
- Bruits may be present
- Signs of poor perfusion
- Other signs of atherosclerosis (IHD, impotence, splanchnic ischaemia)
What are the signs of poor arterial perfusion?
- hair loss
- hypertrophic nails
- atrophic muscle
- skin ulcerations and infections
- poor capillary refill
- prolonged pallor with elevation and rubor on dependency
- venous troughing
Ddx of chronic arterial insufficiency?
- OA: worse at night, varies day-day.
- Neurogenic claudication (due to spinal stenosis/radiculopathy)
- Varicose veins
- Inflammatory (Buerger’s disease, Takayasu’s arteritis)
- Other: popliteal entrapment, radiation injury, trauma
What are the non-invasive Ix of chronic arterial insufficiency?
-ABI:
What are the invasive Ix of chronic arterial insufficiency?
-Arteriography: superior resolution (to MR/CT), better for tibial arteries.
What are the indices for ABI?
Ankle-Brachial Index: >1.2: suspect wall calcification >0.95: normal 0.85-0.94: Mild 0.5-0.84: Mod 0.26-0.49: Severe
Conservative treatments of chronic arterial insufficiency?
- RFx mod: smoking cessation, manage HTN/ hyperlipidemia / DM
- Exercise: improves collaterals / O2 extraction by muscle
- Foot care: esp in DM.
Pharmacotherapy for Mx chronic arterial insufficiency?
- Anti-platelets: e.g. clopidogrel
- Cilostazol: cAMP phosphodiesterase inhibitor with anti-platelet and vasodilatory effects. Improves walking distance
- Pain relief: opiate analgesia, NSAIDs
Surgical Mx of chronic arterial insufficiency?
- Endovascular (stenting/ angioplasty)
- Endarterectomy: remove plaques with patch repair (usually distal aorta/ common femoral)
- Bypass graft
- Chemical sympathectomy (EtOH injected into nerve plexus; rarely effective)
- Amputation
What are the indications for surgical Mx of chronic arterial insufficiency?
Pain interferes with lifestyle, rest pain, night pain, pre-/gangrene.
What are the sites of bypass grafts in chronic arterial insufficiency?
- Aortofemoral
- Axillofemoral
- Femoropopliteal
- Distal arterial
Prognosis for Pts with claudication?
-Conservative Mx: 60-80% improve, 20-30% same, 5-10% deteriorate
If critical limb ischaemia = high risk of limb loss.
What is claudication?
Ischaemic pain in exercising muscles: imbalance b/w demand of muscle and ability to maintain aerobic metabolism -> switch to anaerobic metabolism -> lactic acid build up -> aching discomfort.
Clinical features of claudication?
- Calf pain on exertion (+/- thigh or buttock)
- Onset/severity related to workload
- Relieved with rest
- Reproducible
What is implied by ischaemic rest pain?
Perfusion so poor that anaerobic metabolism present in skin and nerves of distal extremity even at rest
Clinical features of ischaemic rest pain?
- ?aided by gravity: hang foot over bed
- pts awake w/ burning pain in extremity
- worst case: all night sleeping in chair
What are the patterns of lower limb occlusive disease?
-Aorto-iliac (inflow)
-Femoro-popliteal (outflow)
-Tibial/crural
Hx/Exam should be matched to a pattern/combo of patterns
CFx aortoiliac arterioocclusive disease?
- Claudication: calf, thigh, buttock
- Pulses: reduced femoral and below
- ?Bruit over aorta / iliac
CFx femoro-popliteal arterio-occlusive disease?
- Claudication: calf
- Pulses: reasonable femoral, weak/absent popliteal + pedal pulses
- Bruit: line of fem/pop arteries
CFx tibial / crural arterio-occlusive disease?
- Claudication: ?none
- Pulses: pop present, pedal absent
- Bruits: popliteal / upper tibial arteries
What are the interventions available for claudication?
- Angioplasty: +/- stenting (better for short segments, proximal arteries)
- Endarterectomy: short segments
- Bypass: longer blocks
Pros/Cons of endovascular interventions for claudication?
- Quick recovery
- May have access vessel problems
- Chance of thrombosis / embolisation
Risks of open bypass claudication intervention?
- Wound issues
- Cardiac risks etc
- Graft thrombosis
- Long recovery (may be 2-3/12)
