Strategies and outcomes of extracorporeal membrane oxygenation use in peripartum patients: a single institution experience.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) use in peripartum patients is rare, and there is a gap in the literature on the outcomes and guidance on using ECMO in peripartum patients. This study describes ECMO strategies our institution uses for peripartum patients and reports outcomes of ECMO use in peripartum patients with respiratory and/or cardiac failure. METHODS: A case series of all peripartum patients, defined as pregnant or up to 6 weeks after delivery of an infant >20 weeks gestation, from 2018 to 2023 from a single center requiring ECMO support. Patients were included if ECMO was initiated in the setting of cardiac, pulmonary, or combined failure. Patient demographics, operative details, ECMO data, and adverse outcomes for maternal, fetus, and neonates were all collected. RESULTS: Eighteen patients met the inclusion criteria. The cohort had a mean maternal age of 30.7 years old and was racially diverse. A majority of this cohort tested positive for COVID-19 (n = 10, 55%). ECMO was a bridge to recovery for all patients, of whom 14 (78%) were discharged out of the hospital alive. No patients received transplantation or a durable mechanical device. The most common complications were infection (25%) and postpartum hemorrhage (22%). CONCLUSIONS: ECMO use in peripartum patients in a single tertiary center was associated with a high survival rate. Furthermore, a strong multidisciplinary team, careful reevaluation of clinical trajectory, and consideration of complications and risks associated with using ECMO in peripartum patients are possible frameworks to use when challenged with critically ill peripartum patients.

A novel method of transapical ProtekDuo rapid deployment cannula as temporary left ventricular assist device.

Peripheral extracorporeal membrane oxygenation (ECMO) is one of the most common strategies for cardiogenic shock. ECMO cannulation is associated with an increased risk of complications. We describe a minimally invasive, off-pump technique to provide adequate hemodynamic support and left ventricular unloading. A 54-year-old male with nonischemic cardiomyopathy and severe peripheral vascular disease with cardiogenic shock was initially supported with inotropes and an intra-aortic balloon pump. Despite continued support, he continued to deteriorate, and we escalated to a temporary left ventricular support with a CentriMag, using a transapical ProtekDuo Rapid Deployment cannula via mini left-thoracotomy. This approach provides adequate hemodynamic support, left ventricular unloading and early ambulation. After 9 days, the patient's functional status was improved and was medically optimized. The patient received a left ventricular assist device as destination therapy. He was discharged home, resumed his normal activities and has been doing well for more than 27 months.

HLA Sensitization in Patients Bridged to Lung Transplantation With Extracorporeal Membrane Oxygenation.

Lung transplantation is a definitive therapy for many end-stage lung pathologies. Extracorporeal membrane oxygenation (ECMO) is increasingly being used as a bridge to lung transplantation (BTT). HLA sensitization is a major barrier to lung transplantation. The development of HLA sensitization while undergoing ECMO support as a BTT has recently been reported in a 2-patient series. Methods: We performed a retrospective analysis of patients undergoing ECMO as a BTT at a single large academic medical center from January 2016 to April 2022. The study was approved by the institutional review board. We selected patients who had undergone ECMO support for at least 7 d with either negative HLA before cannulation or initial negative HLA on ECMO (3 patients). Results: We identified 27 patients bridged to lung transplantation with available HLA data. Of this group, 8 patients (29.6%) developed significant HLA sensitization (>10%). We did not identify any factors predisposing to sensitization, including infection episodes or blood product transfusion. Sensitized patients demonstrated a trend toward an increased primary graft dysfunction rate, a need for posttransplant ECMO support, and a decreased 1-y survival; however, these did not meet statistical significance. Conclusions: Our study is the largest series today describing the association between HLA sensitization and ECMO therapy. We suggest that interaction between the immune system and ECMO circuit contributes to allosensitization pretransplant, similar to that occurring with ventricular assist device. Further work is needed to better characterize the incidence of HLA sensitization in a multicenter cohort and to identify potentially modifiable factors associated with HLA sensitization.

Low molecular weight hyaluronan inhibits lung epithelial ion channels by activating the calcium-sensing receptor.

Herein, we tested the hypothesis that low molecular weight hyaluronan (LMW-HA) inhibits lung epithelial ions transport in-vivo, ex-vivo, and in-vitro by activating the calcium-sensing receptor (CaSR). Twenty-four hours post intranasal instillation of 50-150 µg/ml LMW-HA to C57BL/6 mice, there was a 75% inhibition of alveolar fluid clearance (AFC), a threefold increase in the epithelial lining fluid (ELF) depth, and a 20% increase in lung wet/dry (W/D) ratio. Incubation of human and mouse precision cut lung slices with 150 µg/ml LMW-HA reduced the activity and the open probability (Po) of epithelial sodium channel (ENaC) in alveolar epithelial type 2 (ATII) cells, and in mouse tracheal epithelial cells (MTEC) monolayers as early as 4 h. The Cl- current through cystic fibrosis transmembrane conductance regulator (CFTR) and the activity of Na,K-ATPase were both inhibited by more than 66% at 24 h. The inhibitory effects of LMW-HA on ion channels were reversed by 1 µM NPS-2143, or 150 µg/ml high molecular weight hyaluronan (HMW-HA). In HEK-293 cells expressing the calcium-sensitive Cl- channel TMEM16-A, CaSR was required for the activation of the Cl- current by LMW-HA. This is the first demonstration of lung ions and water transport inhibition by LMW-HA, and its mediation through the activation of CaSR.

Repair of Tracheal Dehiscence After Heart-Lung Transplant Complicated by SARS-CoV-2 Infection.

Airway complications are a major cause of morbidity after thoracic transplantation. Airway ischemia, necrosis, and tracheobronchial anastomotic dehiscence are associated with early mortality. We describe a case of tracheal anastomotic dehiscence after en bloc heart-lung transplant complicated by severe acute respiratory syndrome coronavirus 2 infection. Timely surgical management and reconstruction with a bovine pericardial patch and double muscle flap were performed. After 8 months of follow-up, there are no airway complications and normalized allograft function.

Bilateral Lung Transplantation With Donor Positive for COVID-19 Infection on Bronchoalveolar Lavage: A Case Report.

Initial experience with lung transplant of COVID-19-positive donors was marked by disappointing results, including a reported case of mortality through donor to recipient transmission of infection. However, since that time a number of improvements in preventative and therapeutic measures against COVID-19 have been developed. We present the case of a 51-year-old woman with scleroderma-associated interstitial lung disease who was awaiting lung transplant. A potential donor with excellent lung physiology was located; however, initial testing on bronchoalveolar lavage (BAL) was positive for COVID-19. The donor had tested positive 2 weeks prior and had symptomatically recovered. Our patient had been fully vaccinated but not seroconverted. Given the history of a donor with recovering COVID infection and a fully immunized recipient, our multidisciplinary team elected to proceed with the transplant. The patient successfully underwent bilateral lung transplant with standard induction immunosuppression. Bebtelovimab was given post-transplant day 1 because the recipient remained seronegative to COVID-19. Serial bronchoalveolar lavages post transplant have been negative for COVID-19. The patient has done well after transplant. She was seen in the clinic 2 months post transplant and is ambulatory without supplemental oxygen requirements. To our knowledge, this represents the first reported successful case of lung transplant with a donor positive for COVID-19 on lower respiratory tract sampling.

State of the art - Extracorporeal membrane oxygenation as a bridge to thoracic transplantation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has revolutionized the treatment of refractory cardiac and respiratory failure, and its use continues to increase, particularly in adults. However, ECMO-related morbidity and mortality remain high. MAIN TEXT: In this review, we investigate and expand upon the current state of the art in thoracic transplant and extracorporeal life support (ELS). In particular, we examine recent increase in incidence of heart transplant in patients supported by ECMO; the potential changes in patient care and selection for transplant in the years prior to updated United Network for Organ Sharing (UNOS) organ allocation guidelines versus those in the years following, particularly where these guidelines pertain to ECMO; and the newly revived practice of heart-lung block transplants (HLT) and the prevalence and utility of ECMO support in patients listed for HLT. CONCLUSIONS: Our findings highlight encouraging outcomes in patients bridged to transplant with ECMO, considerable changes in treatment surrounding the updated UNOS guidelines, and complex, diverse outcomes among different centers in their care for increasingly ill patients listed for thoracic transplant.

Tricuspid surgery at the time of LVAD implant: A critique.

Tricuspid regurgitation (TR) is a common finding in patients with end stage heart failure referred for implantation of left ventricular assist devices. While functional TR frequently resolves after left ventricular unloading, patients with residual and progressive TR demonstrate increased rates of RV dysfunction and poor survival. Criteria for intervention on the tricuspid valve have focused on the degree of tricuspid annular dilatation and the severity of tricuspid regurgitant volume. The surgical decision making regarding intervention on the tricuspid valve remains obscure and historical cohort data cannot distinguish cause from effect.

Pulmonary Transplant After More Than 1 Year of Continuous Ambulatory Extracorporeal Support.

While extracorporeal support of patients awaiting pulmonary transplantation is now well-established, extracorporeal membrane oxygenation (ECMO) remains a nondurable technology deployed for short-term support or recovery in patients with progressive disease. Here, we describe an anecdotal experience with pulmonary transplant after more than 1 year of continuous veno-venous ECMO support. The case highlights several issues relevant to the increasing use of bridging technologies: (1) the potential impact of extracorporeal circulation on immune sensitization, (2) the safety and questionable need for anticoagulation in long-term ambulatory veno-venous extracorporeal support, and (3) the increasing durability of contemporary ECMO support technologies.

Pulmonary vasodilator use in continuous-flow left ventricular assist device management.

Pulmonary hypertension (PH) due to left heart disease is the most common etiology for PH. PH in patients with heart failure with reduced fraction (HFrEF) is associated with reduced functional capacity and increased mortality. PH-HFrEF can be isolated post-capillary or combined pre- and post-capillary PH. Chronic elevation of left-sided filling pressures may lead to reverse remodeling of the pulmonary vasculature with development of precapillary component of PH. Untreated PH in patients with HFrEF results in predominant right heart failure (RHF) with irreversible end-organ dysfunction. Management of PH-HFrEF includes diuretics, vasodilators like angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers or angiotensin-receptor blocker-neprilysin inhibitors, hydralazine and nitrates. There is no role for pulmonary vasodilator use in patients with PH-HFrEF due to increased mortality in clinical trials. In patients with end-stage HFrEF and fixed PH unresponsive to vasodilator challenge, implantation of continuous-flow left ventricular assist device (cfLVAD) results in marked improvement in pulmonary artery pressures within 6 months due to left ventricular (LV) mechanical unloading. The role of pulmonary vasodilators in management of precapillary component of PH after cfLVAD is not well-defined. The purpose of this review is to discuss the pharmacologic management of PH after cfLVAD implantation.

Pulmonary Vascular Disease Due to Plasma Cell Dyscrasia.

Pulmonary hypertension (PH) has been described in myeloproliferative disorders; monoclonal plasma cell disorder such as polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome; and plasma cell dyscrasias such as multiple myeloma and amyloidosis. We describe 4 cases of PH likely due to pulmonary vascular involvement and myocardial deposition from light chain deposition disease, amyloidosis, and multiple myeloma. On the basis of our clinical experience and literature review, we propose screening for plasma cell dyscrasia in patients with heart failure with preserved ejection fraction, unexplained PH, and hematological abnormalities. We also recommend inclusion of cardiopulmonary screening in patients with monoclonal gammopathy of undetermined significance.

Utility of transesophageal echocardiography to assess real time left atrial pressure changes and dynamic mitral regurgitation following placement of transseptal multistage venous cannula for systemic venous drainage and indirect left ventricular venting in venoarterial extracorporeal membrane oxygenation.

A patient with heart failure due to nonischemic cardiomyopathy presented as a transfer to our institution following peripheral (femoral) venoarterial (VA) extracorporeal membrane oxygenation (ECMO) placement. With peripheral VA ECMO cannulation, the patient continued to have unstable ventricular tachyarrhythmias. Echocardiography demonstrated left ventricular (LV) dilation and severe mitral regurgitation (MR) with clinical and chest X-ray evidence of pulmonary edema. To provide venous drainage and simultaneous decompression of the left atrium (LA) and thereby indirect LV venting, a single multistage venous cannula was placed across the inter-atrial septum (IAS) using the previously described left atrial venoarterial (LA-VA) ECMO cannulation technique. Two- and three-dimensional (3D) transesophageal echocardiography (TEE) demonstrated utility in guiding cannula placement into the appropriate position and providing real time assessment of ventricular decompression and MR severity. There was subsequent improvement in pulmonary edema. This case is thought to be the first demonstration of real time resolution of pulmonary venous flow reversal in a patient undergoing LA-VA ECMO cannulation. This demonstration offers important mechanistic insight into some of the potential benefits of such an approach.

Persistent mitral regurgitation after left ventricular assist device: a clinical conundrum.

AIMS: Persistent mitral valve regurgitation (MR) after continuous flow left ventricular assist device implantation (cfLVAD) is associated with pulmonary hypertension and right ventricular failure with variable effects on survival across published studies. The aim of this study is to determine the incidence and predictors of persistent MR at 6-month follow-up after cfLVAD implantation and its impact on survival, haemodynamics, right ventricular function, and morbidity. METHODS AND RESULTS: We performed a retrospective review of all adult cfLVAD recipients from January 2012 to June 2017 at a single tertiary university hospital with follow-up until April 2019. Primary outcome was to compare survival between patients with no-to-mild compared with persistent moderate-to-severe MR at 6 months. Secondary outcomes included right heart failure (RHF), length of stay, re-hospitalizations, and composite of death, transplant, and pump exchange during the length of follow-up. Final analytic sample was 111 patients. The incidence of persistent moderate or severe MR at 6 months was 26%. Significant predictors of persistent MR at 6 months were left atrium dimension and volume. The group with persistent moderate-to-severe MR at 6 months had higher incidence of RHF at 6 months (45% vs. 25%, P = 0.04). There was no difference in survival at 1 year between the groups (no-to-mild MR 85.5%, moderate-to-severe MR 87.9%, Wilcoxon P-value = 0.63). There was no difference in re-hospitalizations, length of stay, composite of death, transplant, or pump exchange during the length of follow-up between the comparison groups. CONCLUSIONS: Persistent moderate-to-severe MR after cfLVAD implantation is present in one fourth of patients and is associated with increased incidence of RHF, higher mean pulmonary pressure, and pulmonary capillary wedge pressure with no effect on 1 year survival. Increased left atrium size was associated with persistent moderate-to-severe MR at 6 months.

Management of reproductive health after cardiac transplantation.

Pregnancy after cardiac transplantation poses immense challenges. Maternal risks include hypertensive disorders of pregnancy, rejection, and failure of the cardiac allograft that may lead to death. Fetal risks include potential teratogenic effects of immunosuppression and prematurity. Because of the high-risk nature of pregnancy in a heart transplant patient, management of reproductive health after cardiac transplantation should include preconception counseling to all women in the reproductive age group before and after cardiac transplantation. Reliable contraception is vital as nearly half of the pregnancies in this population are unintended. Despite the associated risks, successful pregnancies after cardiac transplantation have been reported. A multidisciplinary approach proposed in this review is essential for successful outcomes. A checklist for providers to guide management is provided.

SARS-CoV-2 Infections among Recent Organ Recipients, March-May 2020, United States.

We conducted public health investigations of 8 organ transplant recipients who tested positive for severe acute respiratory syndrome coronavirus 2 infection. Findings suggest the most likely source of transmission was community or healthcare exposure, not the organ donor. Transplant centers should educate transplant candidates and recipients about infection prevention recommendations.

Extracorporeal membrane oxygenation in the management of granulomatosis with polyangiitis.

Granulomatosis with polyangiitis (GPA, also known as Wegener's granulomatosis) is a type of systematic vasculitis that primarily involves the lung and kidney. Diffuse alveolar hemorrhage (DAH) and associated acute respiratory failure are uncommon but devastating complications of GPA. Experience in using extracorporeal membrane oxygenation (ECMO) to manage DAH caused by GPA is limited. We report two GPA patients with DAH that were successfully managed using ECMO support. Examining 13 cases identified in the literature and two of our own, we observed that most patients experienced rapid deterioration in respiratory function in conjunction with a precedent respiratory infection. All 15 patients received veno-venous ECMO support. The median duration of ECMO support was 11 days (interquartile range: 7.5-20.75 days). Bleeding was the most common complication, seen in four (26.7%) cases. All patients were successfully weaned off ECMO after a median length of hospital stay of 42 days (interquartile range: 30-78 days). We demonstrated that the use of ECMO is a reasonable and effective support option in the management of GPA patients with DAH. The risk of bleeding is high but maybe reduced using a lower anticoagulation goal.

Femoral venoarterial extracorporeal membrane oxygenation using a novel biatrial cannula for venous drainage and left ventricular venting.

Extracorporeal life support (ECLS) is an expanding technology for patients in cardiogenic shock. The majority of patients requiring ECLS can be managed with percutaneous venoarterial (VA) femoral cannulation. Despite sufficient extracorporeal circulatory support, a unclear number of patients develop left ventricular distension which can result in increased wall tension and stress as well as worsening pulmonary edema. Indications to vent the left ventricle can be controversial. When venting is indicated, a number of additional procedures may be considered including inotropic support, intra-aortic balloon pump, impella, balloon atrial septostomy, or placement of a transseptal cannula. We present a unique case of a femoral VA extracorporeal membrane oxygenation as a bridge to transplant with left-sided venting using a Bio-Medicus NextGen cannula (Medtronic) with a transseptal approach.

Temporary Circulatory Support With Ventricular Assist Devices: Update on Surgical and Percutaneous Strategies.

PURPOSE OF REVIEW: The available platforms for temporary circulatory support (TCS) have expanded to include impeller technologies in addition to the traditional approaches with centrifugal pumps and intra-aortic counterpulsation. We review the evidence for competing technologies, relative risk, and benefit of individual TCS platforms and provide a consensus opinion in the context of our institutional experience. RECENT FINDINGS: Trans-aortic axial flow devices (Impella) have significantly impacted the support of patients with cardiogenic shock. Despite the absence of prospective randomized data, the use of both percutaneous and surgical Impella devices is ubiquitous among heart failure centers and rapidly evolving. Extracorporeal centrifugal pumps remain the technology of last resort. Despite the increasing use of new TCS platforms, there is little empirical evidence that outcomes have been impacted. Increasingly, systems of care-rather than technology-are seen as the more important variable in the management of patients with cardiogenic shock.