Artificial liver support with the molecular adsorbent recirculating system: activation of coagulation and bleeding complications.

Background: Numerous, mostly uncontrolled, observations suggest that artificial liver support with the Molecular Adsorbent Recirculating System (MARS) improves pathophysiologic sequelae and outcome of acute and acute-on-chronic liver failure. MARS is felt to be safe, but extracorporeal circuits may activate coagulation.

Objective: To assess the frequency of and risk factors for activation of coagulation during MARS treatment.

Patients/methods: Retrospective analysis of coagulopathy/bleeding complications observed during 83 consecutive MARS sessions in 21 patients (11 men; median age 46 years; median three sessions per patient; median duration of session 8 h).

Results: Nine clinically relevant episodes of coagulopathy/bleeding were observed in eight patients, forced to premature cessation of MARS in seven and ended lethal in four. Four complications occurred during the first, five during later (third to seventh) MARS sessions and two bleeders tolerated further sessions without complications. Coagulation parameters worsened significantly also during MARS sessions not associated with bleeding (P< or =0.004). In univariate analysis, patient's age, vasopressor therapy, pretreatment INR, fibrin D-dimer and fibrinogen concentrations, but not severity of underlying disease (MELD, Child-Pugh, SAPS II scores), were significantly associated with coagulopathy (P<0.05). Only patient's age, fibrin D-dimer level and INR were retained in a multivariate model correctly classifying 98% of sessions without, but only 33% with complications.

Conclusion: Coagulation is frequently activated during MARS therapy, potentially leading to bleeding complications and mortality.