12, 5, 16, 17, 34
Most VA complications are decided at cannulation. Three actions carry disproportionate weight: choose the arterial cannula for the vessel rather than the target flow; place the distal perfusion wire before the arterial cannula; and site a right radial arterial line, because it samples what the coronary and cerebral circulations actually receive.
None — textbook chapters
Arterial and venous cannulation for VA support
Entirely expert practice — no randomised or comparative evidence for any technique, size or sequence. No validated cannula-to-vessel ratio threshold at which distal perfusion becomes necessary. No comparative outcome data for femoral versus axillary arterial return. The 5-10% carotid watershed-infarction figure appears in the ISCCM Manual and the J Thorac Dis 2015 review in NEAR-IDENTICAL WORDING, indicating a shared upstream source not retrieved — treat as one unverified claim, not two. Cannula sizes are conventions; device instructions for use govern. Note the recurring transcription hazard: the project's Red Book text renders the sizing convention incorrectly as '1 Fr = 3 mm'; correct is 3 Fr = 1 mm.
Arterial site determines whether differential hypoxaemia is possible: femoral return is retrograde and creates an aortic watershed (typically between ascending aorta and renal arteries, position varying with LV output vs ECMO flow); axillary, subclavian and central return are antegrade and abolish it while lowering LV afterload. SIZING: measure the artery by ultrasound, Fr = diameter in mm x 3, then choose 1-3 Fr SMALLER — an oversized arterial cannula takes the whole lumen and causes distal ischaemia. DISTAL PERFUSION: place the wire BEFORE the arterial cannula, because distal flow is considerably lower afterwards; use a 6-9 Fr reinforced sheath rather than a standard cannula to resist kinking; access the SFA antegrade just past the CFA bifurcation and confirm the wire passes freely down the leg. Alternatives: retrograde posterior tibial, end-to-side graft, chimney (Dacron T) graft. Published sizes: 23 cm femoral arterial cannula; 8 mm axillary graft with 21-24 Fr cannula via a 3-4 cm subclavicular incision distal to the thyrocervical trunk; central 22-24 Fr aortic and 32-46 Fr two-stage venous; 6-8 mm Dacron graft for small vessels. Femoral vessels usable from 15-20 kg upwards. Upper-body cannulation causes distal limb HYPERPERFUSION and compartment syndrome. Carotid return reportedly carries 5-10% risk of large watershed cerebral infarction. Triple cannulation (VVA for drainage/unloading, VAV for combined heart and lung failure) with the added cannula placed under live imaging.
Adults requiring VA ECMO