Perioperative management - Popliteal artery aneurysm: Resection and revascularization with greater saphenous vein graft (posterior access)

Management of popliteal artery aneurysms (PAA) aims to prevent major amputations caused by microemboli in the arteries of the lower leg from the aneurysm. In critical ischemia caused by PAA the rate of major amputation is between 25% and 50%.

Asymptomatic PAA

Surgery is generally recommended for aneurysms measuring 2 cm in diameter and more, since even small aneurysms often become symptomatic. Since in aneurysms smaller than 2 cm with partial wall thrombosis and no pedal pulses "silent" embolization may be possible, the indication for surgery this situation must be determined on a case-by-case basis.

Symptomatic PAA

Acute and chronic critical ischemia, local pressure consequences, venous thrombosis due to compression, septic aneurysm and rupture constitute an indication for surgery regardless of the length or diameter.

In thrombotic PAA occlusion with good collateralization and no intermittent claudication surgery is not mandatory. The indication for surgery in these cases depends on the perfusion situation of the extremity (e.g., PAOD stage III/IV). Autogenous distal crural bypass may be indicated. If the health of the patient is poor or the patient is unable to walk anymore, amputation may be an alternative. 

History/Symptoms

At the time of diagnosis, 80% of PAA are clinically silent and about 14% become symptomatic each year. The symptoms resemble those in peripheral arterial occlusive disease:

• Arterial stenoses
• Microemboli
• Intermittent claudication
• Rest pain
• Trophic disorders

PAA may also manifest as swelling and secondary deep vein thrombosis of the leg.

Contralateral pulse status comparison

Occlusion pressure/ankle-brachial index

Color coded duplex sonography

Modality of choice:

• PAA screening and sizing
• Extent of mural thrombosis
• Runoff situation
• Anatomical variants
• also: preoperative mapping of the greater saphenous vein (= graft material)

CT angiography

• complements ultrasonography for planning the surgical management of the PAA

Cardiac workup

• In suspected myocardial ischemia

Clinical chemistry

• RBC, electrolytes, coagulation panel

Chest radiograph

Screening for

• Aortic aneurysm (in about 20% of patients)
• Contralateral PAA (in about 50% of patients)
• Stenoses of the supraaortic branches require treatment

• If necessary, temporary discontinuation of oral anticoagulants with transition to low molecular weight heparin
• Preoperative mapping of the greater saphenous vein (= graft material)

General risks of surgery

• Allergy/incompatibility
• Wound infection
• Thrombosis/embolism
• Skin/tissue/nerve damage
• Keloids

Specific surgical risks

• Bleeding/secondary bleeding
• Hepatitis/HIV transmission by blood transfusion
• Arterial/venous thrombosis/embolism, microembolization
• Nerve damage
• Occlusion of the graft/bypass with critical ischemia, loss of extremities
• Massive infection of the graft/bypass
• Lymph edema/fistula of the leg
• Compartment syndrome

General anesthesia

The greater saphenous vein is harvested with the patient first supine. In medial access and PI/P III graft, the procedure can be continued in the supine position with the leg slightly flexed. In posterior access, as demonstrated in the video, the patient must be repositioned to the prone position.

For harvesting the greater saphenous vein (with the patient supine), the surgeon stands on the side to be operated on, with the assistant and scrub nurse opposite. In posterior access to the popliteal artery (with the patient prone), the surgeon stands on the affected side, with the assistant and scrub nurse opposite.

In addition to the standard vascular surgery instrument set:

• Asymmetric retractors
• Vascular clamps (coronary bulldog, 120° clamp)
• Rarely: in the absence of autogenous vein alloplastic vascular graft (preferably PTFE)

Postoperative analgesia

Follow these links to Prospect (Procedures Specific Postoperative Pain Management) and the current German guideline Leitlinien der Behandlung akuter perioperativer und posttraumatischer Schmerzen [Guidelines on treatment of acute perioperative and posttraumatic pain].

Postoperative management:

Anticoagulation

• 500 IU heparin/h i.v. via syringe driver for 3 days, on postop. day 1 already overlapping with ASA 100 mg o.d. ( long-term).

Ambulation                                   

• partial weight bearing on postoperative day 1–2, depending on extent of patient cooperation

Physical therapy

• None

Diet

• On day of surgery after 4–6 hours

Bowel movement:

• PRN

Work disability

• Usually 6–8 weeks