Although relative contraindications to VV ECMO have been evolving with technology and experience, they currently include mechanical ventilation for >7 days (with plateau pressure [P_plat] >30 cmH₂O and/or fraction of inspired oxygen [F_iO₂] >90%), intracranial hemorrhage or systemic bleeding, irreversible and incapacitating central nervous system pathology, immunosuppression, terminal malignancy, and advanced age. 

The latest ECMO guidelines do not list obesity as a contraindication.

In fact, studies support the use of VV ECMO in patients with obesity in light of similar or even better survival outcomes compared to their nonobese counterparts. 

However, skepticism still exists, especially for those with extreme body mass index (BMI), defined as super-obese (BMI >50) or super-super obese (BMI >60). Apart from practical challenges, such as cannulation and proning difficulties, the complex pulmonary and cardiovascular pathophysiology associated with extreme obesity carries the risk of inadequate ECMO flows for the body surface area (BSA), with resultant hypoxemia, as well as hemolysis with secondary coagulopathy from required high flows. The study authors report the successful implementation of 2 in-parallel VV ECMO circuits to overcome the limitations encountered in a super-super-obese patient undergoing conventional VV ECMO for refractory respiratory failure.