Lung Transplantation Using a Hybrid Extracorporeal Membrane Oxygenation Circuit.

Extracorporeal circulation (ECC) support using intraoperative extracorporeal membrane oxygenation (ECMO) during lung transplantation (LTx) is now a routine practice for many high volume centers. Circuits that are dedicated to ECMO alone can be expensive and do not allow full cardiopulmonary bypass (CPB) to be performed. We describe our technique of instituting venoarterial ECMO during LTx using a less-expensive hybrid circuit that facilitates easy and immediate conversion to full CPB if needed, without interruption of ECC.

Successful blind lung isolation with the use of a novel double-lumen endobronchial tube in a patient undergoing lung transplantation with massive pulmonary secretion: A case report.

RATIONALE: Precise lung isolation technique with visual confirmation is essential for thoracic surgeries to create a safe and clear surgical field. However, in certain situations, such as when patients have massive pulmonary secretion or when the fiberoptic bronchoscopy (FOB) is not applicable, lung isolation has been performed blindly. PATIENT CONCERN: A 52-year-old woman, whose airway was unable to visualize with FOB due to massive pulmonary secretion, was presented for bilateral sequential lung transplantation. Extracorporeal membranous oxygenation, tracheostomy, and mechanical ventilation were applied to the patient for 39 days preoperatively as a bridge for lung transplantation. DIAGNOSIS: Patient was diagnosed with an idiopathic pulmonary fibrosis and obesity. INTERVENTION: Initially, height-based blind positioning with a conventional double-lumen endobronchial tube (DLT) failed to ventilate the patient properly, and the confirmation of DLT positioning with FOB was impossible due to massive pulmonary secretion. Therefore, a novel DLT (ANKOR DLT) that has one more cuff, located at a point between the distal opening of the tracheal lumen and the starting point of bronchial cuff, than conventional DLT was used for the lung isolation in the patient. OUTCOMES: After the completion of lung graft, FOB finding showed that the ANKOR DLT was optimally positioned at the tracheobronchial tree of the patient, and its depth was 2.5 cm shallower than that of the conventional tube. LESSONS: ANKOR DLT would be a feasible choice to achieve successful blind lung isolation when the use of FOB is impossible to achieve the optimal lung isolation.

EVLP: Ready for Prime Time?

Ex vivo lung perfusion implies perfusion and ventilation of a donor lung outside of the human body. The 2 most clinically relevant and commercially available devices currently in clinical trials are XVIVO Perfusion System (XPS Perfusion, Goteborg, Sweden) and Organ Care System (Transmedics, Andover, MA). Our review focuses on the needs met by ex vivo lung perfusion, and the clinical literature on both devices.

A simple technique can reduce cardiopulmonary bypass use during lung transplantation.

Cardiopulmonary bypass causes an inflammatory response and consumption of coagulation factors, increasing the risk of bleeding and neurological and renal complications. Its use during lung transplantation may be due to pulmonary hypertension or associated cardiac defects or just for better exposure of the pulmonary hilum. We describe a simple technique, or open pericardium retraction, to improve hilar exposure by lifting the heart by upward retraction of the pericardial sac. This technique permits lung transplantation without cardiopulmonary bypass when bypass use is recommended only for better exposure.

Regeneration of the lung: Lung stem cells and the development of lung mimicking devices.

Inspired by the increasing burden of lung associated diseases in society and an growing demand to accommodate patients, great efforts by the scientific community produce an increasing stream of data that are focused on delineating the basic principles of lung development and growth, as well as understanding the biomechanical properties to build artificial lung devices. In addition, the continuing efforts to better define the disease origin, progression and pathology by basic scientists and clinicians contributes to insights in the basic principles of lung biology. However, the use of different model systems, experimental approaches and readout systems may generate somewhat conflicting or contradictory results. In an effort to summarize the latest developments in the lung epithelial stem cell biology, we provide an overview of the current status of the field. We first describe the different stem cells, or progenitor cells, residing in the homeostatic lung. Next, we focus on the plasticity of the different cell types upon several injury-induced activation or repair models, and highlight the regenerative capacity of lung cells. Lastly, we summarize the generation of lung mimics, such as air-liquid interface cultures, organoids and lung on a chip, that are required to test emerging hypotheses. Moreover, the increasing collaboration between distinct specializations will contribute to the eventual development of an artificial lung device capable of assisting reduced lung function and capacity in human patients.

A simple technique can reduce cardiopulmonary bypass use during lung transplantation

Cardiopulmonary bypass causes an inflammatory response and consumption of coagulation factors, increasing the risk of bleeding and neurological and renal complications. Its use during lung transplantation may be due to pulmonary hypertension or associated cardiac defects or just for better exposure of the pulmonary hilum. We describe a simple technique, or open pericardium retraction, to improve hilar exposure by lifting the heart by upward retraction of the pericardial sac. This technique permits lung transplantation without cardiopulmonary bypass when bypass use is recommended only for better exposure.

Novel Uses of Extracorporeal Membrane Oxygenation in Adults.

Extracorporeal membrane oxygenation (ECMO) has been available for decades, with its use steadily expanding in the setting of advances in technology. The most common indications for venovenous and venoarterial ECMO remain severe hypoxemic respiratory failure and cardiogenic shock, respectively. Refinements in extracorporeal circuitry and cannulation strategies have led to novel indications for ECMO in cardiopulmonary failure, including pulmonary hypertension, extracorporeal cardiopulmonary resuscitation, and less severe forms of the acute respiratory distress syndrome. There is hope for the development of destination device therapy, which could have significant implications for acute and chronic management of severe respiratory and cardiac disease.

Method of isolated ex vivo lung perfusion in a rat model: lessons learned from developing a rat EVLP program.

The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. As this technology expands and improves, the ability to potentially evaluate and improve the quality of substandard lungs prior to transplant is a critical need. In order to more rigorously evaluate these approaches, a reproducible animal model needs to be established that would allow for testing of improved techniques and management of the donated lungs as well as to the lung-transplant recipient. In addition, an EVLP animal model of associated pathologies, e.g., ventilation induced lung injury (VILI), would provide a novel method to evaluate treatments for these pathologies. Here, we describe the development of a rat EVLP lung program and refinements to this method that allow for a reproducible model for future expansion. We also describe the application of this EVLP system to model VILI in rat lungs. The goal is to provide the research community with key information and "pearls of wisdom"/techniques that arose from trial and error and are critical to establishing an EVLP system that is robust and reproducible.

Utilization of the organ care system as ex-vivo lung perfusion after cold storage transportation.

The Organ Care System (OCS) allows perfusion and ventilation of the donor lungs under physiological conditions. Ongoing trials to compare preservation with OCS Lung with standard cold storage do not include donor lungs with suboptimal gas exchange and donor lungs treated with OCS following cold storage transportation. We present a case of a 48-yr-old man who received such lungs after cold storage transportation treated with ex-vivo lung perfusion utilizing OCS.

Utilization of a novel rib spreader for minimally invasive lung transplantation.

Rack-and-pinion-type stainless steel rib spreader was innovated by Truffier in 1914, which was modified by Finochietto to have fenestrated blades and a hand-cranked lever to both separate the arms in a staged fashion and lock them in place at each stop. Its Burford-Finochietto variants with replaceable blades are ubiquitous in open thoracic surgery. Fehling Surgical Instrument, Inc (Acworth, GA) introduced a modified rib spreader-an assembly of movable and adjustable blades, a mobile bridge and spreader arms, which owing to its adaptation of thoracotomy incision provides an optimum exposure without injuring the ribs. The spreader is indispensible in lung transplantation surgery performed especially through minimally invasive (bilateral limited anterolateral thoracotomies with intact sternum) approach.

Ex-vivo lung perfusion.

This review outlines the new and promising technique of ex vivo lung perfusion and its clinical potential to increase the number of transplantable lungs and to improve the early and late outcome after transplantation. The rationale, the experimental background, the technique and protocols, and available devices for ex vivo lung perfusion are discussed. The current clinical experience worldwide and ongoing clinical trials are reviewed.

Successful prolonged ex vivo lung perfusion for graft preservation in rats.

OBJECTIVES: Ex vivo lung perfusion (EVLP) strategies represent a new frontier in lung transplantation technology, and there have been many clinical studies of EVLP in lung transplantation. The establishment of a reliable EVLP model in small animals is crucial to facilitating translational research using an EVLP strategy. The main objective of this study was to develop a reproducible rat EVLP (R-EVLP) model that enables prolonged evaluation of the explanted lung during EVLP and successful transplantation after EVLP. METHODS: The donor heart-lung blocks were procured with cold low-potassium dextran solution and immersed in the solution for 1 h at 4 °C. And then, the heart-lung blocks were flushed retrogradely and warmed up to 37 °C in a circuit perfused antegradely with acellular perfusate. The perfusate was deoxygenated with a gas mixture (6% O2, 8% CO2, 86% N2). The perfusion flow was maintained at 20% of the entire cardiac output. At 37 °C, the lungs were mechanically ventilated and perfusion continued for 4 h. Every hour, the perfused lung was evaluated for gas exchange, dynamic lung compliance (Cdyn) and pulmonary vascular resistance (PVR). RESULTS: R-EVLP was performed for 4 h. Pulmonary oxygenation ability (pO2/pCO2) was stable for 4 h during EVLP. It was noted that Cdyn and PVR were also stable. After 4 h of EVLP, pO2 was 303 ± 19 mmHg, pCO2 was 39.6 ± 1.2 mmHg, PVR was 1.75 ± 0.10 mmHg/ml/min and Cdyn was 0.37 ± 0.03 ml/cmH2O. Lungs that were transplanted after 2 h of R-EVLP resulted in significantly better post-transplant oxygenation and compliance when compared with those after standard cold static preservation. CONCLUSIONS: Our R-EVLP model maintained stable lung oxygenation, compliance and vascular resistance for up to 4 h of perfusion duration. This reliable model should facilitate further advancement of experimental work using EVLP.

Airway fire during double-lung transplantation.

Airway fire is a well-documented event during airway surgery with devastating outcomes. Individuals involved in the care of these patients should be aware of this possible complication and precautions needed to prevent this complication.

Crossed wiring closure technique for bilateral transverse thoracosternotomy is associated with less sternal dehiscence after bilateral sequential lung transplantation.

OBJECTIVE: Bilateral transverse thoracosternotomy (clamshell incision) is a widely used approach in bilateral sequential lung transplantation, but the closure technique is associated with sternal dehiscence. This study compares the incidence of sternal dehiscence between the crossed and uncrossed closure techniques. METHODS: In 129 patients who underwent transplantation through a clamshell incision, the sternum was closed using either the crossed or the uncrossed method based on the surgeon's preference. The position of the sternal parts was evaluated on lateral chest radiographs and scored as normal, override, or separation. RESULTS: We observed sternal override in 38 patients and separations in 18 patients. The sternum was closed using the uncrossed method in 79 patients and the crossed method in 50 patients. There were significantly fewer overrides (n = 6, 12.0%) and separations (n = 6, 12.0%) of the sternal parts using the crossed closure technique compared with the uncrossed technique (32 overrides, 41.0%; and 12 separations, 15.1%; P < .001). Reconstructive surgery was only performed in patients with separation of the sternal parts (n = 10). CONCLUSIONS: Using the crossed closure technique for the sternum after bilateral sequential lung transplantation reduces the incidence of sternal dehiscence compared with the uncrossed closure technique and, therefore, reduces the necessity of reconstructive surgery.

Artificial lung and novel devices for respiratory support.

There is a growing demand for new technology that can take over the function of the human lung, whether it is to assist an injured or recently transplanted lung or to completely replace the native lung. The use of extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation was reported for the first time more than 3 decades ago; nevertheless, its use in lung transplantation was largely abandoned owing to poor patient survival and frequent complications. ECMO as a bridge to lung transplantation has significantly increased during the past 10 years. This increase in utilization is reflected in the growing success reported with the use of different ECMO modalities in patients awaiting lung transplantation. The use of ECMO is now being considered in awake and nonintubated patients so as to improve oxygenation, facilitate ambulation, and improve physical conditioning before transplant. Several programs have developed ambulatory capability of most forms of ECMO, and ambulatory ECMO is now often referred to as the "artificial lung." We present a brief description of the evolution of the use of ECMO in lung transplantation and summarize the available technology and current approaches to provide ECMO support.

Rigid bronchoscopic management of complications related to endobronchial stents after lung transplantation.

OBJECTIVES: We reviewed the utility of rigid bronchoscopy in the management of complications resulting from placement of metallic endobronchial stents after lung transplantation. METHODS: A retrospective review was performed of all lung transplant patients who required metallic endobronchial stenting between 2005 and 2009. The patients' medical records were reviewed, and details regarding stent placement, complications, and removal were recorded. RESULTS: A total of 43 metallic stents were placed in 22 patients who had unilateral or bilateral lung transplantation. Stent complications occurred in 18 cases (42%) at a mean of 285 days after placement and included stent collapse, stent breakdown, stent migration, ingrowth of granulation tissue, and coughing up of fractured pieces of stent. Of the 43 stents placed, only 4 (9%) had to be removed. Removal was readily accomplished by rigid bronchoscopic techniques, even when some endothelial ingrowth had occurred. CONCLUSIONS: Lung transplantation presents unique challenges in airway management. Endobronchial stenting plays an important role in the management of anastomotic stenosis and bronchomalacia in these patients. Although metallic stents have significant advantages, complications often arise that occasionally necessitate their removal. Rigid bronchoscopy is a valuable tool in the management of endobronchial stent complications after lung transplantation.

[Ex situ tracheobronchoplastic operations using the organ care system]. / Broncho-/tracheoplastische Ex-situ-Operationen im "organ care system"

First clinical experiences with the organ care system (OCS) in lung transplantation showed that this device allows perfusion and ventilation of the lungs under practically physiological conditions. Some pulmonary pathologies necessitate ex situ operations, e.g. to avoid pneumonectomy. The objective of this work was to investigate the feasibility of ex situ pulmonary surgery within the OCS.In the first procedure a large tracheobronchial leakage was covered with a pericardial patch. The procedure was authorized by the local committee of animal welfare. In the second surgery a replacement of the distal trachea using an aortic graft was performed after removal of the heart-lung segment from a pig from the slaughterhouse. The postoperative ventilation of both lungs was free of problems. The mean pressure of the pulmonary artery remained steady during the whole experiment. The setup to prevent lung edema was basically successful.Performing thoracic surgery with the OCS is feasible; however, this approach is reserved for very special indications. Further investigations to optimize technical details of the OCS setup for this purpose are necessary.