Thromboembolic Events in Patients on Extracorporeal Membrane Oxygenation Without Anticoagulation

Objective: Heparinization is thought to be mandatory to avoid thromboembolic complications during venoarterial extracorporeal membrane oxygenation (VA-ECMO). However, bleeding complications are common. We report our experience of VA-ECMO without systemic anticoagulation. Methods: A prospectively assembled database describing all ECMO cases from 2000 to 2008 was analyzed. A heparin coated circuit (Medtronic, Inc., Minneapolis, MN USA) and membrane oxygenator (Quadrox D Bioline oxygenator; MAQUET, Rastatt, Germany) were used in all cases. After the initiation of VA-ECMO support, all coagulation parameters were corrected. No further systemic maintenance anticoagulant was given, except at the time of weaning. Results: Thirty-two patients received VA-ECMO support; 20 patients (62.5%) were males with a median age of 52.5 years (interquartile range, 40.4-61.1 years). Central and peripheral cannulations were 53% and 47%, respectively. Etiologies of cardiogenic shock were postcardiotomy (75%, n = 24) and as a support to cardiopulmonary resuscitation in 25% of cases (n = 8). Thirty-day mortality was 43.8%. Median duration of ECMO support was 46.3 hours (interquartile range, 26.8-87.8 hours). The median number of packed red blood cell transfusions was 18 +/- 25. Complications include five patients (16%) with limb ischemia requiring intervention, 15 patients (46.9%) had acute renal failure, two patients had deep vein thrombosis, and two patients had intracardiac clots detected on echocardiograms. No patient had a cerebrovascular event. Incidence of membrane oxygenator failure was low, requiring replacement in three patients; no adverse event occurred during replacement. Fourteen patients (43.8%) were reexplored for bleeding. Fourteen patients (44%) were discharged home and were long-term survivors. Conclusions: VA-ECMO support without systemic anticoagulation may reduce bleeding complications and transfusion requirement, without increasing the risk of thromboembolism.