Three Cases of Severe Pulmonary Embolism After Dual-Lumen Extracorporeal Membrane Oxygenation Catheter Removal.

To the Editor: With great interest we read the article by Cooper et al (1), published in a recent issue of Critical Care Medicine. In this article, frequent deep vein thrombosis after extracorporeal membrane oxygenation (ECMO), especially in patients with dual-lumen catheters, is reported. Neither Cooper et al nor Shafii et al (2) reported any thromboembolic event related to post-ECMO thrombosis. At our ECMO center (treating an average of 55 ECMO patients per year over the last 4 yr), we had to face three patients (medium age, 52.2 yr) with sudden respiratory and right heart failure within 12 hours aver removal of a 31F bi-caval dual-lumen catheter (AVALON ELITE Bi-Caval Dual Lumen Catheter, Maquet, Germany). During ECMO therapy, we administer unfractionated heparin targeting an activated clotting time of 50–60 seconds. Heparininduced thrombocytopenia was ruled out in two patients with the clinical suspicion of HIT. Before removal, there was no clinical sign of thrombosis in any patients. Two of the three patients had a CT scan performed, which showed pulmonary embolism, and an IV lysis therapy was administered. One patient could be stabilized by using catecholamines and unfractionated heparin and no lysis was indicated. Fortunately, all patients survived the thromboembolic complication. We, therefore, established a routine ultrasound study before removal of dual-lumen catheters. We strongly support the call for further research in postECMO thrombosis. Apart from prevalence of thrombosis and subsequent embolism, the best treatment algorithm (local catheter-based lysis vs rescue lysis or even surgical removal) has to be addressed. The authors have disclosed that they do not have any potential conflicts of interest.