Thoracic Surgical Procedures Supported by a Pumpless Interventional Lung Assist

Extracorporeal Membrane Oxygenation Use in Thoracic Surgery

This narrative review is focused on the application of extracorporeal membrane oxygenation (ECMO) in thoracic surgery, exclusive of lung transplantation. Although the use of ECMO in this indication is still rare, it allows surgery to be performed in patients where conventional ventilation is not feasible-especially in single lung patients, sleeve lobectomy or pneumonectomy and tracheal or carinal reconstructions. Comparisons with other techniques, various ECMO configurations, the management of anticoagulation, anesthesia, hypoxemia during surgery and the use of ECMO in case of postoperative respiratory failure are reviewed and supported by two cases of perioperative ECMO use, and an overview of published case series.

The Right Ventricle During Selective Lung Ventilation for Thoracic Surgery

The right ventricle (RV) has been an area of evolving interest after decades of being ignored and considered less important than the left ventricle. Right ventricular dysfunction/failure is an independent predictor of mortality and morbidity in cardiac surgery; however, very little is known about the incidence or impact of RV dysfunction/failure in thoracic surgery. The pathophysiology of RV dysfunction/failure has been studied in the context of acute respiratory distress syndrome (ARDS), cardiac surgery, pulmonary hypertension, and left ventricular failure, but limited data exist in literature addressing the issue of RV dysfunction/failure in the context of thoracic surgery and one-lung ventilation (OLV). Thoracic surgery and OLV present as a unique situation where the RV is faced with sudden changes in afterload, preload, and contractility throughout the perioperative period. The authors discuss the possible pathophysiologic mechanisms that can affect adversely the RV during OLV and introduce the term RV injury to the myocardium that is affected adversely by the various intraoperative factors, which then makes it predisposed to acute dysfunction. The most important of these mechanisms seems to be the role of intraoperative mechanical ventilation, which potentially could cause both ventilator-induced lung injury leading to ARDS and RV injury. Identification of at-risk patients in the perioperative period using focused imaging, particularly echocardiography, is paramount. The authors also discuss the various RV-protective strategies required to prevent RV dysfunction and management of established RV failure.

Principles and indications of extracorporeal life support in general thoracic surgery

The role of extracorporeal life support (ECLS) has expanded rapidly over the past 15 years to become an important tool in advanced general thoracic surgery practice. Intra-operative and in some cases continued post-operative ECLS is redefining the scope of complex surgical care. ECLS encompasses a spectrum of temporary mechanical support that may remove CO₂, oxygenate or provide hemodynamic support or a combination thereof. The most common modalities used in general thoracic surgery include extracorporeal membrane oxygenation (ECMO), interventional lung assist device (iLA^® Novalung^®, Heilbronn, Germany), and extracorporeal CO₂ removal (ECCO₂R). The ECMO and Novalung^® devices can be used in different modes for the short term or long-term support depending on the situation. In this review, the principles and current applications of ECLS in general thoracic surgery are presented.

[The role of extracorporeal removal of CO2 (ECCO2R) in the management of respiratory diseases]

INTRODUCTION

The aim of extracorporeal removal of CO₂ (ECCO₂R) is to ensure the removal of CO₂ without any significant effect on oxygenation. ECCO₂R makes use of low to moderate extracorporeal blood flow rates, whereas extracorporeal membrane oxygenation (ECMO) requires high blood flows.

STATE OF THE ART

For each ECCO₂R device it is important to consider not only performance in terms of CO₂ removal, but also cost and safety, including the incidence of hemolysis and of hemorrhagic and thrombotic complications. In addition, it is possible that the benefits of such techniques may extend beyond simple removal of CO₂. There have been preliminary reports of benefits in terms of reduced respiratory muscle workload. Mobilization of endothelial progenitor cells could also occur, in analogy to the data reported with ECMO, with a potential benefit in term of pulmonary repair. The most convincing clinical experience has been reported in the context of the acute respiratory distress syndrome (ARDS) and severe acute exacerbations of chronic obstructive pulmonary disease (COPD), especially in patients at high risk of failure of non-invasive ventilation.

PERSPECTIVES

Preliminary results prompt the initiation of randomized controlled trials in these two main indications. Finally, the development of these technologies opens new perspectives in terms of long-term ventilatory support.

Intraoperative Management of Hypercapnia With an Extracorporeal Carbon Dioxide Removal Device During Giant Bullectomy

Extracorporeal CO2-removal devices have been introduced in clinical practice to provide protective and ultraprotective ventilation strategies in different settings to avoid retention of carbon dioxide. The need to facilitate lung-protective ventilation is required not only for the treatment of acute respiratory distress syndrome but also in thoracic surgery during complex operations, especially in respiratory compromised patients. This report describes a case of giant bullectomy for vanishing lung syndrome in which intraoperative hypercapnia secondary to protective ventilation was managed with a CO2-removal device (Decap-Hemodec s.r.l., Salerno, Italy). To the best of our knowledge, this is the first report in the literature of the intraoperative use of the Decap system for giant bullectomy.

Current Applications for the Use of Extracorporeal Carbon Dioxide Removal in Critically Ill Patients

Mechanical ventilation in patients with respiratory failure has been associated with secondary lung injury, termed ventilator-induced lung injury. Extracorporeal venovenous carbon dioxide removal (ECCO₂R) appears to be a feasible means to facilitate more protective mechanical ventilation or potentially avoid mechanical ventilation in select patient groups. With this expanding role of ECCO₂R, we aim to describe the technology and the main indications of ECCO₂R.

Extracorporeal support for pulmonary resection: current indications and results

Extracorporeal assistances are exponentially used for patients, with acute severe but reversible heart or lung failure, to provide more prolonged support to bridge patients to heart and/or lung transplantation. However, experience of use of extracorporeal assistance for pulmonary resection is limited outside lung transplantation. Airways management with standard mechanical ventilation system may be challenging particularly in case of anatomical reasons (single lung), presence of respiratory failure (ARDS), or complex tracheo-bronchial resection and reconstruction. Based on the growing experience during lung transplantation, more and more surgeons are now using such devices to achieve good oxygenation and hemodynamic support during such challenging cases. We review the different extracorporeal device and attempt to clarify the current practice and indications of extracorporeal support during pulmonary resection.

Intraoperative veno-venous extracorporeal lung support in thoracic surgery: a single-centre experience

OBJECTIVES

Intraoperative extracorporeal lung support (ECLS) during thoracic surgical procedures is a modern concept that is gaining increasing acceptance. So far, cardiopulmonary bypass (CPB), veno-arterial extracorporeal membrane oxygenation (v-a-ECMO) or pumpless arterio-venous interventional lung assist (iLA) were utilized for intraoperative support. Only a few case reports have described the use of veno-venous ECMO for intraoperative ECLS. Here, we report our experience with intraoperative ECLS using different veno-venous low-flow and high-flow settings adapted to the individual patient requirements.

METHODS

Between April 2014 and April 2015, 9 patients underwent pulmonary resections under ECLS. In 6 patients, a twin-port double-lumen cannula was inserted percutaneously into the right femoral vein for low-flow ECLS. In 3 patients, high-flow ECLS was achieved either by femoro-atrial (n = 1) or femoro-jugular cannulation.

RESULTS

Indications for ECLS were severely impaired lung function (n = 3), previous pulmonary resections including contralateral pneumonectomy (n = 4), previous single-lung transplantation (sLTX) (n = 1) and extended carinal pneumonectomy (n = 1). Procedures included segmentectomy (n = 3), extended lobectomy with bronchial and vascular anastomoses (n = 1), VATS lobectomy (n = 2), extended left-sided carinal pneumonectomy (n = 1) as well as extended metastasectomy (n = 2). Low-flow ECLS allowed for apnoea up to 45 min in patients with previous pneumonectomy (n = 3) and facilitated protective single-lung ventilation in patients (n = 3) with severely impaired pulmonary function. During trans-sternal carinal pneumonectomy (n = 1), high-flow ECLS achieved by femoro-atrial cannulation allowed for apnoea for 40 min, avoiding cross-field ventilation. In 2 patients requiring extended metastasectomy after previous lobectomy of the contralateral lower lobe (n = 1) or pulmonary metastases in the graft after sLTX for end-stage fibrosis (n = 1), high-flow ECLS by percutaneous femoro-jugular cannulation allowed for extensive metastasectomy under optimal atelectasis of the lung.

CONCLUSIONS

For intraoperative ECLS, different modes may be applied depending on the intended procedures and required mechanical ventilation. In our experience, different settings of veno-venous ECLS provide sufficient partial or complete lung support, avoiding possible complications associated with other forms of extracorporeal support such as CPB or v-a-ECMO.

Extracorporeal membranous oxygenation (ECMO) in polytrauma: what the radiologist needs to know

The purpose of this article is to review the spectrum of severe traumatic injuries treatable with ECMO and their imaging features, considerations for cannula placement, and complications that may arise in polytraumatized patients on extracorporeal life support. Recent major advances in miniaturization and biocompatibility of ECMO devices have dramatically increased their safety profile and expanded the application of ECMO to patients with severe polytrauma.

[Postoperative respiratory insufficiency and its treatment]

The development of a postoperative respiratory insufficiency is typically caused by several factors and include patient-related risks, the extent of the procedure and postoperative complications. Morbidity and mortality rates in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are high. It is important to have consistent strategies for prevention and preoperative conditioning is essential primarily for high-risk patients. Treatment of established postoperative lung failure requires early tracheotomy, protective ventilation (tidal volume 6 ml/kg body weight), elevated positive end expiratory pressure (PEEP, 10-20 mmH2O), recurrent bronchoscopy and early patient mobilization. In critical cases an extracorporeal lung assist is considered to be beneficial as a bridge to recovery and for realizing a protective ventilation protocol. Different systems with separate indications are available. The temporary application of a lung assist allows thoracic surgery to be performed safely in patients presenting with insufficient respiratory function.

Low-Flow Veno-Venous Extracorporeal CO2 Removal: First Clinical Experience in Lung Transplant Recipients

Background

Low-flow extracorporeal CO2 removal devices are easy to setup and manage and may provide valuable ventilation support.

Methods

We employed a new device (ProLUNG) recently introduced into the clinical arsenal that exploits a simple hemoperfusion technique sustained by blood flows lower than 500 ml/min to remove CO2 from the venous blood. It was used as an adjunctive support to mechanical ventilation during and after four lung transplantations in our center.

Results

Two patients with cystic fibrosis, one with pulmonary fibrosis, and one with emphysema were included. They underwent lung transplantation and presented hypercapnia and respiratory acidosis before, during, or after the surgical procedure. After 1 h of treatment with the ProLUNG circuit, all patients showed reduced CO2 levels and increased pH; these variables remained stable until the end of treatment.

Conclusions

Our data suggest that this new device is effective in removing CO2 and stabilizing the pH.

Disruptive technology in the treatment of thoracic trauma

The care of patients with thoracic injuries has undergone monumental change over the past 25 years. Advances in technology have driven improvements in care, with obvious benefits to patients. In many instances, new or "disruptive" technologies have unexpectedly displaced previously established standards for the diagnosis and treatment of these potentially devastating injuries. Examples of disruptive technology include the use of ultrasound technology for the diagnosis of cardiac tamponade and pneumothorax; thoracoscopic techniques instead of thoracotomy, pulmonary tractotomy, and stapled lung resection; endovascular repair of thoracic aortic injury; operative fixation of flail chest; and the enhanced availability of extracorporeal lung support for severe respiratory failure. Surgeons must be prepared to recognize the benefits, and limits, of novel technologies and incorporate these methods into day-to-day treatment protocols.

Extracorporeal life support for acute respiratory distress syndromes

The morbidity and mortality of acute respiratory distress syndrome remain to be high. Over the last 50 years, the clinical management of these patients has undergone vast changes. Significant improvement in the care of these patients involves the development of mechanical ventilation strategies, but the benefits of these strategies remain controversial. With a growing trend of extracorporeal support for critically ill patients, we provide a historical review of extracorporeal membrane oxygenation (ECMO) including its failures and successes as well as discussing extracorporeal devices now available or nearly accessible while examining current clinical indications and trends of ECMO in respiratory failure.

In-parallel attachment of a low-resistance compliant thoracic artificial lung under rest and simulated exercise

BACKGROUND

Previous thoracic artificial lungs (TALs) had blood flow impedance greater than that of the natural lungs, which could cause abnormal pulmonary hemodynamics. New compliant TALs (cTALs), however, have an impedance lower than that of the natural lung.

METHODS

In this study, a cTAL of new design was attached between the pulmonary artery (PA) and the left atrium (LA) in 5 sheep (60.2 ± 1.9 kg). A distal PA band was placed to control the percentage of cardiac output (CO) routed to the cTAL. Rest and exercise conditions were simulated using a continuous dobutamine infusion of 0 and 5 μg/kg/min, respectively. At each dose, a hemodynamic data set was acquired at baseline (no flow to the cTAL), and 60%, 75%, and 90% of CO was shunted to the cTAL.

RESULTS

Device resistance did not vary with blood flow rate, averaging 0.51 ± 0.03 mm Hg/(L/min). Under all conditions, CO was not significantly different from baseline. Pulmonary system impedance increased above baseline only with 5 μg/kg/min of dobutamine and 90% of CO diverted to the cTAL.

CONCLUSIONS

Results indicated minimal changes in pulmonary hemodynamics during PA-LA cTAL attachment for high device flows under rest and exercise conditions.

Extracorporeal Carbon Dioxide Removal (ECCO2R) in Respiratory Failure: An Overview, and where Next?

Extracorporeal carbon dioxide removal (ECCO2R) is used to facilitate protective ventilation strategies and to treat severe hypercapnic acidosis that is refractory to mechanical ventilation. There is an increasing amount of interest in the use of ECCO2R but there are no recommendations for its use that take the most recent evidence into account. In 2008, the National Institute of Health and Clinical Excellence (NICE) published guidelines on ‘Arteriovenous Extracorporeal Membrane Carbon Dioxide Removal.’1 However, since that time there have been a number of studies in the area and some significant technological advances including the introduction of commercially available VV-ECCO2R systems. The aim of this article is to provide an overview of ECCO2R, review the literature relating to its use and discuss its future role in the intensive care setting.

Extracorporeal CO(2) removal in ARDS

Acute respiratory distress syndrome remains one of the most clinically vexing problems in critical care. As technology continues to evolve, it is likely that extracorporeal CO(2) removal devices will become smaller, more efficient, and safer. As the risk of extracorporeal support decreases, devices' role in acute respiratory distress syndrome patients remains to be defined. This article discusses the functional properties and management techniques of CO(2) removal and intracorporeal membrane oxygenation and provides a glimpse into the future of long-term gas-exchange devices.

Extracorporeal membrane oxygenation support for resection of locally advanced thoracic tumors

BACKGROUND

The international experience with resection of advanced thoracic malignancies performed with extracorporeal membrane oxygenation (ECMO) support is limited. We examined our results to assess the risks and benefits of this approach.

METHODS

We retrospectively analyzed all patients with thoracic malignancies who underwent tumor resection with ECMO support in our department between 2001 and 2010.

RESULTS

Nine patients (aged 21 to 71 years; mean, 54.8±7.5 years) underwent complex tracheobronchial resections (n=6) or resections of greater thoracic vessels (n=3) under venoarterial (VA) ECMO support. In 7 patients the underlying pathologic condition was non-small cell lung cancer, in 1 patient it was carcinoid tumor, and in 1 patient it was synovial sarcoma. The indication for extracorporeal support was complex tracheobronchial reconstruction (n=5), resection of the descending aorta (n=2), and resection of the inferior vena cava (n=1). ECMO cannulation was central (n=4), peripheral (n=4), or combined (n=1). Mean time on bypass was 110±19 minutes (range 40 to 135 minutes). A complete resection (R0) was achieved in 8 patients (89%). One patient died perioperatively as a result of hepatic necrosis. Eight patients were discharged from the hospital after 7 to 42 days (median, 10 days). Median time in the intensive care unit was 1 day (range, 0 to 36 days). The only complication related to the use of ECMO was a lymphatic fistula in the groin. Mean follow-up time was 38±42 months (range, 9 to 111 months). The actuarial 3-month survival was 88.9%, and the 1-year, 3-year, and 5-year survival was 76.7%.

CONCLUSIONS

Based on this experience, we consider VA ECMO support to be a safe alternative to cardiopulmonary bypass (CPB) for advanced general thoracic operations.