Perioperative management - Left lateral alloplastic anterior tibial bypass according to Stockmann for PAOD stage IV

Compared to occlusion processes of the superficial femoral artery and more proximally located artery segments, occlusions of the cruro-pedal arteries often lead primarily to critical limb ischemia due to their limited collateralization possibilities. Diabetics are particularly affected by this.

Endovascular therapy options for infragenual occlusion processes should be preferred over surgery, provided that the expected short- and long-term results are comparable. Nevertheless, even today, in selected cases, there is a primary indication for the primary use of pedal and peripheral crural bypass surgery:

• extensive tissue lesions on the foot (primary bypass graft offers stronger tissue perfusion compared to endovascular therapy → “straight to the foot”)
• complex, long-segment occlusion processes
• failure of endovascular treatment

Further prerequisites are:

• acceptable surgical risk
• adequate life expectancy
• connectable peripheral vessel

In the optimal case, revascularization is performed using autologous bypass material (e.g., great saphenous vein).

Film example

• subtotal stenoses of the left superficial femoral artery
• occlusion of the popliteal artery segments I – III
• partial occlusions of all lower leg arteries
• occlusion of the primary and secondary foot arches

Status post femoro-popliteal vein bypass on the right, autologous great saphenous vein used up, left too small caliber → alloplastic bypass.

• too high surgical risk, e.g. ASA IV
• Infection in the area of the planned access sites
• Status post radiation of the groin (then extra-anatomical procedures required)
• existing loss of function of the extremity (joint contractures, bedridden state)

History

• Claudication
• Walking distance
• Risk factors → Smoking, arterial hypertension,  CHD, heart failure, diabetes mellitus, hyperlipidemia, manifest renal insufficiency with/without dialysis requirement, coagulopathies

Inspection

• Skin changes
• Muscular abnormalities
• Orthopedic malpositions
• Skin color
• Hair growth
• Trophic changes
• Swelling, edema, mycoses, phlegmons, leg ulcers etc.    

Side-comparative palpation

• Pulse status
• Skin temperature

Side-comparative auscultation of the extremity arteries

Ankle-Brachial Index (ABI)

• ABI = systolic BP posterior tibial artery/systolic BP brachial artery

• An ABI value of < 0,9 is considered proof of the presence of relevant PAD.
• The determination of the ankle-brachial index (ABI) by non-invasive measurement of the Doppler occlusion pressure is a suitable test for detecting PAD.
• For the diagnosis of PAD, the ABI value with the lowest ankle artery pressure is decisive.
• A pathological ankle-brachial index is an independent risk indicator for increased cardiovascular morbidity and mortality.

Color-coded duplex sonography

• Carotid, abdominal aorta, extremity arteries
• Localization of stenoses and occlusions in almost all vascular regions except in the thoracic area
• Quantification of the degree of stenosis and assessment of plaque morphology possible
• Sensitivity and specificity approx. 90 %   
• Well suited as a screening method
• Vein mapping for identifying suitable bypass material (omitted in the film example) preferably great saphenous vein; alternatively small saphenous vein, superficial arm veins (cephalic vein, basilic vein)
  • Available length, diameter, patency
  • Diameter preferably more than 3 mm without varicose changes

CT angiography

• Multi-slice computed tomography (MS-CT) using non-ionic contrast medium
• Broad spectrum of indications: traumatic vascular lesion (esp. trunk), vascular dissection/rupture, aneurysm, arterial thrombosis/embolism, portal vein/mesenteric vein thrombosis, pulmonary artery embolism, PAD, vascular tumors
• Advantages: quick to perform, detection of relevant comorbidities, visualization of peripheral arteries, sensitivity and specificity each approx. 90 %
• Disadvantages: Radiation and contrast medium exposure, allergies (approx. 3 %), no functional assessment

Cardiac check

• Resting ECG
• Exercise ECG
• Echocardiography

Chest X-ray

If necessary, spirometry

Laboratory

• CBC
• Electrolytes
• Coagulation
• Retention values
• Liver enzymes
• Blood lipids
• Blood group
• In PAD stage IV → wound swab/antibiogram

• Mark side, shave (lower abdomen, groin, leg)
• Fasting 6 hours
• Cotton shoe to avoid positioning-related pressure injuries
• Leave aggregation inhibitors; in dual therapy individual decision depending on cardiac risk profile
• Provide blood products
• Antibiotic therapy according to antibiogram (see Diagnostics) for 5 days postoperatively depending on local findings

General Surgical Risks

• Severe bleeding, blood transfusions, transmission of Hepatitis/HIV through blood products
• Allergy/Intolerance
• Wound infection
• Thrombosis/Embolism
• Skin, vascular, nerve damage e.g. due to positioning
• Keloids

Specific Procedure Risks

• Bypass occlusion and possibly adjacent vessel segment due to thrombosis; surgical revision, (partial) amputation
• Massive infections with severe bleeding from bypass suture sites; bypass removal, (partial) amputation, sepsis
• Injury to sensory and motor nerves; dysesthesias, pain, temporary or persistent (partial) paresis of thigh muscles
• Damage to lymphatic vessels; temporary or persistent lymphedema, lymph fistula
• Persistent reperfusion edema; compartment syndrome; possibly surgical decompression/fasciotomy, persistent paresis, limb loss
• Renal dysfunction with temporary or permanent dialysis due to tourniquet syndrome and intraoperative angiography (contrast medium)
• Suture site aneurysm; surgical intervention depending on size/clinical presentation