FRCS Postgraduate vascular surgery Flashcards
What are the most common peripheral aneurysms?
Popliteal aneurysms
What is the incidence of contralateral popliteal aneurysms?
50%
What is the incidence of abdominal aortic aneurysms?
5-10%
What is the prevalence of popliteal aneurysms in the 8th decade of life?
1%
What is the most common presentation of popliteal artery aneurysms?
Distal ischemic complications
When presenting acutely with distal limb ischemia, what is the % of limb loss?
50%
What are broad treatment options for popliteal aneurysms?
- Open repair
- Endovascular repair
- Medical management with anticoagulation (exclusively in patients with very diseased run-off to reduce risk of aneurysm thrombosis)
How is the popliteal artery palpated?
The artery is best palpated against the tibia in the midline of the popliteal fossa, with the knee in the extended position (with a few degrees of flexion). The artery can also be palpated with the knee flexed to 130 degrees, in this position the fascia loosens to aid palpation. However, in doing this maneuver it deepens the artery from the skin surface
Differential diagnosis for posterior knee swellings?
- Popliteal artery
- Baker’s cyst
- Semimembranosus bursa
Where do Baker’s cysts originate and how do they present?
They originate below the knee joint as it extends beneath the gastronemius muscle. Associated with signs and symptoms of degenerative arthritis of the knee joint.
Where do semimembranosus bursa originate?
They originate medially along the popliteal edge of the semimembranosus muscle.
How do popliteal aneurysms present?
Acute:
1. Distal ischemia secondary to thrombosis or embolisation
Chronic:
- Intermittent claudication secondary to chronic embolisation to tibial vessels
- Compressive symptoms from compression to nerves, vein causing DVT
- Asymptomatic
What is the rate of popliteal aneurysm rupture?
Tell me about the anatomy of the popliteal artery.
The popliteal artery starts when the SFA passes through the adductor hiatus in the thigh. The vessel terminates as it splits into the AT and the tibioperoneal trunk at the lower border of the popliteus muscle.
The popliteal artery gives off several genicular branches at several points to form a large collateral around the knee joint.
The artery is the deepest structure in the popliteal fossa and sits beneath the popliteal vein. The tibial nerve lies superficial to the popliteal vein.
How woukd approach the proximal popliteal artery?
Can be approached posteriorly, laterally or medially.
Most common route is medial approach.
The suprageniculate popliteal artery is accessed via an incision in the distal third of the thigh along the anterior border of the sartorius muscle. The muscle is mobilised posteriorly and the artery is identified between the medial intramuscular septum anteriorly and semimembranosus muscle posteriorly.
How woukd approach the distal popliteal artery?
Can be approached posteriorly, laterally or medially.
Most common route is medial approach.
The infrageniculate artery is exposed medially via a longitudinal incision, 1cm behind the posterior/medial border of the tibia. The LSV or GSV is usually located posterior to the incision and care must be made not to damage it. A tissue plane is created bluntly between the soleus and gastrocnemius muscles. The tendons of sartorius, gracilis, and semitendinosus often require division for more proximal access. The popliteal vein must be mobilised as this sits in front of the artery from this approach.
What are your indications for elective repair of popliteal aneurysms?
- Size: PAs> 2cm
2. Patient factors: fitness, anatomical configuration, distal embolisation, critical ischemia, thrombus
When is thrombolysis used?
10% of patients who are lysed, the limb deteriorates during the lysis process because a large volume of thromboembolic material is destabilized and embolises distally.
The main role of thrombolysis is on table to clear thrombus from distal tibial run off vessels during the process of revascularization
What problem faces endovascular treatment of PAs?
Main concerns regarding stent grafts relate to long-term durability. With the constant flexing of the knee joint, the physical stresses challenge the integrity and positioning of popliteal stent grafts.
5 year patency of popliteal stents?
75%
