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.

Table 2 Studies depicting limb ischemia, distal perfusion catheter insertion and outcomes

Ref.	Type of study	Distal perfusion catheter strategy	Limb ischemia incidence	Impact of acute limb ischemia on outcomes
Kaufeld et al[30], 2019	DPC strategy based	Upfront prophylactic (77%) vs none	3.38% with DPC vs 21.42% without DPC	Absence of DPC identified as an independent risk factor for critical limb ischemia (P < 0.001). Authors suggest to have mandatory distal limb perfusion
Lamb et al[6], 2017	DPC strategy based	Upfront prophylactic (60%)	0% with DPC vs 33% without DPC	Survival in patient with ALI was 25% compared to 42% overall survival; only 1 patient required amputation. Continuous monitoring with NIRS suggested if DPC not placed prophylactically
Son et al[2], 2021	DPC strategy based	Selective monitored (44%)	20% incidence of ALI	DPC placement did not significantly reduce the risk of ALI
Liao et al[15], 2020	DPC strategy based	Upfront prophylactic (100%)	20.11% incidence of ALI	Peripheral artery disease was the primary independent risk factor for ALI despite DPC
Hu et al[17], 2022	DPC strategy based	Rescue (only after clinical signs)	Limb ischemia complications were noted in 10.6% of total patients, with 8.4% patients requiring a rescue DPC	Authors suggest to optimize cannulation strategies during establishment of VA-ECMO
Lunz et al[10], 2019	DPC strategy based	Selective monitored (50% of ALI cases)	43.9% incidence of ALI	Cannula size and indication of ECMO noted to be most important factors for development of ALI
Yau et al[14], 2019	DPC strategy based	Upfront prophylactic (29.8%)	22% incidence of ALI	Lack of prophylactic DPC or arterial cannula size not primary drivers of ALI, rather younger patients, history of diabetes and peripheral arterial disease are at increased risk of ALI
Kim et al[31], 2017	ALI monitoring based	Upfront prophylactic (noted as insufficient without NIRS)	ALI incidence not explicitly given for the group	0% fasciotomy rate in NIRS group vs 13.9% in the control group (P = 0.04). Also, the mean time to distal perfusion was shorter in NIRS group, suggesting the early institution of NIRS to be valuable
Vinogradsky et al[32], 2023	ALI monitoring based	Selective monitored (NIRS-guided placement)	Limb ischemia requiring surgical intervention in NIRS group (2.6%) vs non-NIRS group (8.5%)	Continuous NIRS monitoring as guidance for selective insertion of DPC is an effective strategy

DPC: Distal perfusion catheter; ALI: Acute limb ischemia; NIRS: Near-infrared spectroscopy; OR: Odds ratio; ECMO: Extracorporeal membrane oxygenation; VA-ECMO: Veno-arterial extracorporeal membrane oxygenation.

Table 3 Strategies for distal perfusion catheter insertion in veno-arterial extracorporeal membrane oxygenation with patient-profile guidance

DPC strategy	Definition	Ideal patient profile	Rationale
Upfront prophylactic	DPC placed at the time of arterial cannulation before any ischemic signs appear	(1) High-risk anatomy (small femoral artery, PAD, diabetes); (2) Large-bore arterial cannula (≥ 19-21 Fr); (3) Anticipated prolonged VA-ECMO run; (4) Obesity or difficult future access; and (5) History of limb ischemia or prior ECMO-related ALI	Prevents early ischemia, avoids emergent intervention, stabilizes distal perfusion from the outset
Selective monitored	No initial DPC; limb is closely monitored with predefined triggers for insertion	(1) Low-to-moderate ischemia risk; (2) Adequate femoral artery size; (3) Short ECMO duration expected; (4) Reliable monitoring available (NIRS, Doppler, serial exams); and (5) Percutaneous cannulation with minimal vascular trauma	Avoids unnecessary DPC placement while enabling timely intervention when early ischemic changes develop
Rescue	DPC inserted only after acute limb ischemia has already developed	(1) Rapidly progressive or established ischemia; (2) Late presenters without prior prophylactic DPC; (3) Cannula-related complications (malposition, thrombosis, dissection); and (4) Emergent ECMO cannulation where prophylaxis was not feasible	Salvage strategy to restore perfusion and prevent irreversible tissue injury, often combined with additional vascular procedures

DPC: Distal perfusion catheter; PAD: Peripheral arterial disease; ECMO: Extracorporeal membrane oxygenation; ALI: Acute limb ischemia; NIRS: Near-infrared spectroscopy.