Mitigating limb ischemia in veno-arterial extracorporeal membrane oxygenation: A narrative review of evolving role of distal perfusion catheters

Table 1 Pathophysiological risk factors and impact on limb ischemia

Risk factor category	Specific risk factor	Pathophysiological impact and mechanism of ischemia	Ref.
Demographic factors	Younger age	Younger patients often have smaller femoral artery diameters and a paucity of collateral circulation, making them more susceptible to luminal obstruction by large cannulas. They may also be more prone to reactive vasospasm	Foley et al[12]
	Female sex	Women generally have smaller arterial diameters than men, which may increase the risk of flow compromise when large cannulas are used	Kim et al[13]
Comorbidities	Peripheral arterial disease	Pre-existing atherosclerosis increases the risk of plaque dislodgement and distal embolism during cannulation. Diseased vessels are also more prone to dissection during the procedure	Yau et al[14], Liao et al[15], Zimpfer et al[16]
	Diabetes mellitus	Chronic microvascular disease and endothelial injury in diabetic patients likely impair the limb's ability to compensate for hypoperfusion, especially in low-flow states	Hu et al[17]
	Chronic pulmonary disease (COPD/bronchial asthma)	Associated with an inflammatory state that induces endothelial damage and is often linked to subclinical or undiagnosed atherosclerotic plaque burden	Yau et al[14]
Procedural/mechanical factors	Arterial cannula size	Large-bore cannulas cause mechanical obstruction of the femoral artery, significantly reducing or completely blocking antegrade blood flow to the distal limb	Lunz et al[10]
	Absence of distal perfusion	Without an antegrade distal perfusion catheter, the limb remains dependent on collateral flow which is often insufficient to overcome the cannula-related obstruction	Lamb et al[6]
	IABP co-insertion	Concurrent use of an intra-aortic balloon pump often requires bilateral femoral cannulation, compounding the risk of arterial obstruction and distal malperfusion	Hu et al[17]
	Cannulation setting (bedside vs OR)	Bedside/ICU cannulations, often performed during active resuscitation (ECPR), are associated with higher risks of vascular injury, hematomas, and suboptimal placement compared to the controlled OR environment.	Son et al[2]
Clinical/hemodynamic status	High VIS-max	High doses of vasopressors induce peripheral vasoconstriction, which, when superimposed on mechanical cannula obstruction, critically impairs distal tissue perfusion	Hu et al[17]
	Low baseline perfusion	Lower baseline tissue oxygenation (rSO2) values prior to cannulation may indicate pre-existing vascular optimization needs or heightened sensitivity to flow changes	Coelho et al[18]

COPD: Chronic obstructive pulmonary disease; IABP: Intra-aortic balloon pump; OR: Operation room; ICU: Intensive care unit; ECPR: Extracorporeal cardiopulmonary resuscitation; VIS: Vasoactive-inotropic score; rSO2: Regional oxygen saturation.