Venoarterial Extracorporeal Membrane Oxygenation in High-Risk Pulmonary Embolism: A Case Series and Literature Review.

Background: High-risk Pulmonary Embolism (PE) has an ominous prognosis and requires emergent reperfusion therapy, primarily systemic thrombolysis (ST). In deteriorating patients or with contraindications to ST, Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) may be life-saving, as supported by several retrospective studies. However, due to the heterogeneous clinical presentation (refractory shock, resuscitated cardiac arrest (CA) or refractory CA), the real impact of VA-ECMO in high-risk PE remains to be fully determined. In this study, we present our centre experience with VA-ECMO for high-risk PE. Method: From 2008 to 2020, we analyzed all consecutive patients treated with VA-ECMO for high-risk PE in our tertiary 35-bed intensive care unit (ICU). Demographic variables, types of reperfusion therapies, indications for VA-ECMO (refractory shock or refractory CA requiring extra-corporeal cardiopulmonary resuscitation, ECPR), hemodynamic variables, initial arterial blood lactate and ICU complications were recorded. The primary outcome was ICU survival, and secondary outcome was hospital survival. Results: Our cohort included 18 patients (9F/9M, median age 57 years old). VA-ECMO was indicated for refractory shock in 7 patients (2 primary and 5 following resuscitated CA) and for refractory CA in 11 patients. Eight patients received anticoagulation only, 9 received ST, and 4 underwent surgical embolectomy. ICU survival was 1/11 (9%) for ECPR vs 3/7 (42%) in patients with refractory shock (p = 0.03, log-rank test). Hospital survival was 0/11 (0%) for ECPR vs 3/7 for refractory shock (p = 0.01, log-rank test). Survivors and Non-survivors had comparable demographic and hemodynamic variables, pulmonary obstruction index, and amounts of administered vasoactive drugs. Pre-ECMO lactate was significantly higher in non-survivors. Massive bleeding was the most frequent complication in survivors and non-survivors, and was the direct cause of death in 3 patients, all treated with ST. Conclusions: VA-ECMO for high-risk PE has very different outcomes depending on the clinical context. Furthermore, VA-ECMO was associated with significant bleeding complications, with more severe consequences following systemic thrombolysis. Future studies on VA-ECMO for high-risk PE should therefore take into account the distinct clinical presentations and should determine the best strategy for reperfusion in such circumstances.

Veno-venous extra-corporeal membrane oxygenation in complex tracheobronchial resection.

Background: Elective extra-corporeal membrane oxygenation (ECMO) is rarely used in thoracic surgery, apart from lung transplantation. The purpose of this study was to summarize our institutional experience with the intraoperative use of veno-venous (VV) ECMO in selected cases of main airway surgery. Methods: We retrospectively analyzed the data of 10 patients who underwent main airway surgery with the support of VV-ECMO between June 2013 and August 2022. Results: Surgical procedures included: three carinal resection and reconstruction with complete preservation of the lung parenchyma, one right upper double-sleeve lobectomy and hemi-carinal resection, and one sleeve resection of the left main bronchus after previous right lower bilobectomy, for thoracic malignancies; four tracheal/carinal repair for extensive traumatic laceration; one extended tracheal resection due to post-tracheostomy stenosis in a patient who had previously undergone a left pneumonectomy. The median intraoperative VV-ECMO use was 162.5 minutes. In three cases with complex resection and reconstruction of the carina and in one case of extended post-tracheostomy stenosis and previous pneumonectomy, high-flow VV-ECMO allowed interruption of ventilation for almost 3 hours. In four patients, VV-ECMO was prolonged in the postoperative period to ensure early extubation. There were no perioperative deaths, no complications related to the use of ECMO and no intraoperative change in the planned type of ECMO. Significant complications occurred only in one patient who developed a small anastomotic dehiscence that led to stenosis and required placement of a Montgomery tube. At the median follow-up of 30 months, all 10 patients were still alive. Conclusions: The use of intraoperative VV-ECMO allows safe and precise performance of main airway surgery with minimal postoperative morbidity in patients requiring complex resections and reconstructions and in cases that cannot be managed with conventional ventilation techniques.