Tuesday, December 15, 2009

Popliteal aneurysms

Clinical presentation
- 30-50% are asymptomatic at time of presentation
- symtpomatic patients most commonly present with acute lower extremity thrombosis or embolism
- recurrent claudication or thromboembolism
- local compression can also result in mass sensation, vein compression, dvt, nerve impingement, impaired mobility of knee joint.
- rupture is rare
- the detection of a prominent popliteal aneurysm is very sensitive. Pulseless mass usually represents a thrombosed aneurysm
- Ddx. Baker's cyst

Investigations.
- plain films usually not useful
- arterial Doppler US is sensitive and ideal for serial imaging. CTA may not show aneurysm if thrombosed to leave only normal caliber lumen, but necessary for preop planning

Managment of asymptomatic patients:
- natural history of popliteal aneurysms is unknown.
- managment largely depends on comorbid risk vs risk of procedure.
- generally 2-3 cm cutoff is used as threshold for operative management in good risk patients
- anticoagulation has not been shown to prevent embolic complications
- 5 year 65% patency rates in symptomatic patients. Lower than latency rates in asymptomatic patients.
- factors which may sway towards operative management. >3cm, large amounts of mural thrombus, unstable thrombus seen on us monitoring, evidence of silent embolization with loss of runoff vessels, aneurysms with a great deal of distortion, distortion of popliteal a above or below aneurysm


Operative Technique
- if pt presents with acute thrombosis or thromboembolism, intraarterial thrombolysis +/- catheter based mechanical thrombectomy devices may help to reestavlish blood flow.
- some believe that provides more gradual reperfusion vs embolectony and therefore reduces incidence of compartment syndrome.
- motor or sensory deficits would be an indication for operative approach.

- exclusion and bypass are the principles of treatment generally
- saphenpus vein grafts are ideal but ringed gortex graft is a reasonable alternative
- ruptures popliteal aneurysm treated same way as ruptured AAA
- endovascular stenting is gaining popularity


- Posted from iPhone

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