**1.2 Incidence of limb ischemia**

ECLS, essentially being temporary mechanical circulatory support requires an exit strategy with a sustainable solution, namely short or long-term ventricular assist device or transplant. Until then, an uninterrupted and uncomplicated distal limb perfusion is essential for the continuation of peripheral ECLS for more than a few hours. Any complications during the period on ECLS support potentially hinder patients' progress to recovery or long-term solutions. Of these, limb ischemia is one of the notorious and unfortunately- most commonly encountered complications in patients supported. As with other complications, limb ischemia remains underreported in institutional audits and the literature and reported incidence of ECLS related limb ischemia vary significantly. The Extra-corporeal Life Support Organisation (ELSO) in its latest report shows 1% incidence of limb ischemia [12]. Whereas, a recent metanalysis reviewing 20 studies comprising 1886 patients revealed a pooled estimate of rate of limb ischemia as high as 16.9% (12.5–22.6%); compartment syndrome at 10.3% (7.3–14.5%) and amputation at 4.7% (2.3–9.3%) [13]. Other contemporary, smaller reviews report limb ischemia in range of 4.4– 19% and 11–52% [14, 15]. The variation among published literature in incidence of limb ischemia and related complications may be due to difference in inclusion criteria of patients, difference in definition of limb ischemia and publication bias.
