Vascular Surgery Flashcards
Clinical features of acute arterial ischemia?
6Ps- all may not be present
• Pain: may be constant or elicited by passive movement
• Pallor: pale within a few hours becomes mottled cyanosis
• Paresthesia: light touch lost first then other sensory modalities
• Paralysis/Power loss: most important, heralds impending non-salvageable limb
• Polar/Poikilothermia: cold leg becomes cold
• Pulselessness: helpful to determine site of occlusion
Urgent management required as skeletal muscle can tolerate ___ of total ischemia before irreversible damage
6 h
Definition of acute arterial ischemia?
Acute occlusion of a peripheral artery that often threatens limb viability
Suspect embolism in patients with the following features
- Acute onset (patient able to accurately recall the moment of the event)
- History of embolism
- Known embolic source (e.g. cardiac arrhythmias)
- No prior history of intermittent claudication
- Normal pulse and Doppler in unaffected limb
Embolism vs. thrombosis
- Thrombosis is more common than embolism; usually in superficial femoral artery
- Existing atherosclerotic plaques can rupture causing thrombosis
- Previous vascular grafts/reconstructions can fail and thrombose leading to acute presentation
- Hypercoagulable states can contribute to thrombosis
- Embolism generally results in greater degree of ischemia due to lack of collaterals
Risk factors of embolism?
- Cardiac: arrhythmias, endocarditis, MI, LV aneurysm, myxoma/cardiac tumour, paradoxical embolism, valvular heart disease
- Non-cardiac: mural thrombus within arterial aneurysms, atheroembolism
Risk factors of thrombosis?
- Atherosclerotic obstruction
- Vasospasm
- Aortic or arterial dissection
- Arterial transection
Investigations of acute arterial ischemia?
- Determine Rutherford classification based on physical findings and Doppler signals
- Ankle Brachial Index (ABI)
- ECG, troponin: rule out recent MI or arrhythmia
- CBC: rule out leukocytosis, thrombocytosis or thrombocytopenia in patients receiving heparin (may suggest HITS)
- PT/INR, PTT: patient anticoagulated/sub-therapeutic INR
- Echo: identify wall motion abnormalities, intracardiac thrombus, valvular disease, aortic dissection (Type A)
- CT angiogram: identify underlying atherosclerosis, aneurysm, aortic dissection, identify embolic source, identify other end organs with emboli (e.g. splenic/renal infarcts), identify level of the occlusion and extent
- Angiography: can be obtained in OR as part of intervention or for treatment planning
Rutherford ALI Category I Visible description?
Not immediately threatened
Rutherford ALI Category IIa Marginally description?
Salvageable if promptly treated
Rutherford ALI Category IIb Immediately description?
Salvageable with immediate revascularization
Rutherford ALI Category III Irreversible description?
Major tissue loss or permanent nerve damage inevitable
Rutherford ALI Category I Visible findings?
Sensory Loss: None
Muscle Weakness: None
Arterial: Audible
Venous: Audible
Rutherford ALI Category IIa Marginally findings?
Sensory Loss: Minimal or none
Muscle Weakness: None
Arterial: Inaudible
Venous: Audible
Rutherford ALI Category IIb Immediately findings?
Sensory Loss: More than toes, associated with rest pain
Muscle Weakness: Mild, moderate
Arterial: Inaudible
Venous: Audible