Acute kidney failure (AKI) is one of the most important causes of morbidity and mortality for critical ill patients. The use of blood purification treatment such as renal replacement therapy (CRRT) and plasma exchange has gradually developed into an effective treatment. However, the efficiency of blood purification may be affected by the recirculation of dual-lumen venous catheter for some special patients including patients with vena cava reflux disorder from massive occupations or ascites. For extreme cases like patients with vena cava disconnection or severe obstruction, the traditional blood purification treatment cannot work effectively. Thus, we used the dual-cannula in jugular-femoral venous blood purification therapy in the following two patients and found that it can improve the perfusion of systemic circulation and the prognosis of patients

Inclusion Criteria:

• 1. patients requiring haemodilution therapy for various reasons (acute renal failure, acute liver failure, etc.)
• 2. presence of superior vena cava and/or inferior vena cava reflux disorders
• 3. age greater than 18 years

Exclusion Criteria:

• 1. Inability to establish suitable vascular access
• 2. Pregnant women
• 3. Not agreeing to active life support treatment
• 4. Severe active bleeding