Use of Artificial Lung Replacement Techniques in Lung Surgery: Expert Interview with Dr. Redwan

Dr. med. univ. Bassam Redwan, FRCP, FACS, is a leading specialist in the field of thoracic surgery and, as a senior attending physician at Klinikum Westfalen, plays a central role in the treatment of diseases of the chest. His expertise includes, in particular, the surgical treatment of lung cancer, bronchovascular reconstructions, tracheal surgery, and minimally invasive procedures such as uniportal video-assisted thoracic surgery (VATS). These state-of-the-art procedures make it possible to treat early-stage tumors gently and precisely, offering patients a faster recovery and a better quality of life.

With over 15 years of experience and more than 50 scientific publications, Dr. Redwan has made a decisive contribution to the advancement of his field. His fellowship in the Royal College of Physicians (FRCP) and the American College of Surgeons (FACS) underscores his high professional standards and his recognition by leading international professional societies. In addition to lung cancer surgery, Dr. Redwan’s areas of expertise include procedures for mediastinal masses as well as lesions of the chest wall, pleura, and diaphragm.

His expertise also extends to the use of extracorporeal membrane oxygenation (ECMO) systems, which can be lifesaving in critical cases.  As a multilingual physician who is fluent in Arabic, English, Spanish, and German, he cares for a wide range of patients and is able to fully take their individual needs and cultural backgrounds into account. Dr. Redwan is not only dedicated to clinical practice but also serves as an academic lecturer at various universities, where he passes on his knowledge to the next generation of physicians.

His work at the Lung Cancer Center at Knappschaft Kliniken in Lünen, which is distinguished by state-of-the-art equipment and the highest medical standards, enables him to offer patients optimal, multidisciplinary care. This center, which was founded in 2017 and has since been certified by the German Cancer Society, is characterized by close collaboration between the Department of Thoracic Surgery, Pulmonology, and other specialized partners. With his dedication and passion for thoracic surgery, he plays a crucial role in offering patients with complex chest conditions new prospects and innovative treatment options.

In a conversation with the experienced thoracic specialist, the editorial team of the Leading Medicine Guide learned more about artificial lung replacement procedures performed during lung surgery.

Lung diseases are among the most common and serious health problems worldwide. They range from chronic conditions such as asthma and COPD to life-threatening conditions such as lung cancer or acute respiratory failure. What many people don’t know is that, thanks to modern medicine, there are now innovative approaches that offer hope even when a patient’s own lungs can no longer function adequately. Lung replacement procedures, such as extracorporeal membrane oxygenation (ECMO), open up new possibilities for patients with the most severe lung damage. These highly advanced technologies can not only save lives but also provide time for healing processes or transitions to other forms of therapy.

A lung replacement procedure, such as extracorporeal membrane oxygenation (ECMO), is a medical technology that temporarily takes over the function of the lungs when they are no longer able to transport sufficient oxygen into the blood or remove carbon dioxide from the body. 

“The concept of lung replacement therapy is based on a principle found in nature. After all, every expectant mother also functions as an artificial lung for her unborn child. A child cannot breathe with its lungs in the womb because it is submerged in fluid. And so the most natural artificial lung is the umbilical cord. The child also produces so-called waste products such as carbon dioxide, and the oxygen-poor and carbon dioxide-rich blood is returned to the mother via the umbilical vein. She carries out the exchange in her own body via her lungs and returns oxygen-rich blood to the child via the umbilical artery. The concept is therefore quite simple. Efforts to translate this into medical applications began as early as the 1930s, but the idea was pursued more intensively on a larger scale starting in the 1950s. What is not yet possible today is providing complete outpatient care for patients with end-stage lung failure using an implantable artificial lung—as is otherwise common for patients with artificial hearts—though this will certainly come in the future. In the lung replacement procedure used today, blood is drawn from the patient, usually from a femoral vein via an inserted cannula. The blood is oxygenated in the machine through an artificial membrane and simultaneously cleared of excess carbon dioxide before being pumped back into the body. “This lung replacement procedure, initially known as ECMO (extracorporeal membrane oxygenation), is now referred to by the umbrella term ECLS (extracorporeal lung support),” explains Dr. Redwan.

---

VV-ECMO (veno-venous ECMO) and VA-ECMO (veno-arterial ECMO) are forms of extracorporeal membrane oxygenation used in cases of severe lung or heart failure. VV-ECMO supports lung function exclusively by drawing venous blood, enriching it with oxygen, and returning it to a vein. It is primarily used in cases of severe lung failure, such as ARDS, when the heart is still functioning adequately. VA-ECMO, on the other hand, supports both lung and heart function. In this procedure, blood is drawn from a vein, oxygenated, and then pumped back into an artery. It is used in cases of severe heart failure or cardiogenic shock, as it also stabilizes circulation. Whether VV-ECMO or VA-ECMO is used depends on whether only the lungs or both the lungs and the heart require support.

---

The duration of treatment varies depending on the cause and severity of the condition. While the procedure is often used only for the duration of surgery, in cases of severe lung failure it may take several days to weeks to allow the lungs time to recover or to bridge the gap until a possible transplant. Once lung function has stabilized, the patient is gradually weaned off the machine. During this process, the support provided by the device is reduced to test the lungs’ ability to function on their own. 

A lung replacement procedure such as extracorporeal membrane oxygenation (ECMO) is used in patients whose lung function is so severely impaired that they are no longer able to supply the body with sufficient oxygen or remove excess carbon dioxide. 

“Patients who are candidates for lung replacement therapy can be divided into two groups. First, there is the group of patients with classic lung failure, known as Acute Respiratory Distress Syndrome (ARDS), which occurs more frequently during the colder months of the year and ultimately involves inflammation of the lungs. In this case, a lung replacement procedure helps in a manner similar to dialysis for kidney failure. The second group of patients includes people whose lungs are so severely diseased that they are already on a waiting list for an organ transplant and whose health has deteriorated to the point where mechanical ventilation is required. However, mechanical ventilation can be harmful in the long term, as it places additional strain on the lung tissue and causes further damage. An example of this is patients with severe lung hyperinflation (emphysema), in whom the so-called “respiratory pump” fails, making mechanical ventilation a consideration. Mechanical ventilation is not beneficial for such patients; therefore, efforts are made to avoid long-term mechanical ventilation, and in some cases, the lung replacement procedure is even used while the patient is awake,” explains Dr. Redwan, elaborating on the procedure in more detail:

“For patients with classic lung failure, a single session of the lung replacement procedure is usually sufficient. As a rule, these patients are already in the intensive care unit, where the artificial lung is used to facilitate regeneration—a process that can take several weeks to months. For example, an 18-year-old patient was treated with lung replacement therapy in our intensive care unit for 53 days and was able to fully recover. The patient’s age plays an important role here—for people over 70, long-term lung replacement therapy is often less suitable, as pre-existing conditions, reduced regenerative capacity, and higher complication rates decrease the chances of success.”

Patients with advanced, irreversible lung diseases who have no prospect of recovery even with ECMO, or those with severe comorbidities such as uncontrolled infections, end-stage malignant diseases, or severe multi-organ failure, generally do not benefit from this procedure. The risk of complications such as bleeding, thrombosis, infections, or mechanical problems with the device must also be taken into account when selecting patients.

The availability of artificial lung support procedures, particularly extracorporeal membrane oxygenation (ECMO), has revolutionized thoracic surgery by making high-risk procedures significantly safer and more successful.

“Lung replacement procedures are used in the context of complex thoracic surgical procedures, which is also my area of focus at the clinic in Lünen. A distinction is made between functional and technical reasons for using lung replacement procedures. In patients with impaired lung function—for example, when the left lung had to be removed due to tumor surgery and the patient develops a new tumor in the right lung years later. Due to the absence of the second lung, surgery to remove the lung tumor is only possible with the use of a lung replacement procedure,” explains Dr. Redwan.

In thoracic surgery, there are numerous situations in which lung function cannot be temporarily maintained during a procedure, such as during the removal of large tumors, bronchovascular reconstructions, or procedures on the trachea (tracheal surgery). In the past, such procedures were associated with a high risk of intraoperative complications such as severe hypoxia (oxygen deficiency) or cardiovascular instability. 

“Patients with pulmonary emphysema resulting from chronic obstructive pulmonary disease (COPD) also benefit from lung replacement procedures. It’s important to understand that inhalation is normally not a problem, as the airways expand during this process. Chronic inflammation causes the airways to narrow due to increased tissue growth within them. As a result, a certain amount of air remains in the lungs with every breath. A person breathes about 16 times per minute and inhales about half a liter of air per breath. If some of the air remains in the lungs each time, this volume gradually increases, leading to significant overinflation of the lung tissue (pulmonary emphysema). If these patients then require lung surgery—whether due to cancer or because lung volume reduction surgery must be performed—and they were ventilated using conventional methods, this could result in additional damage to the lungs. Using a lung replacement procedure creates a much more relaxed atmosphere during the necessary surgery, because the lung being ventilated does not need to be ventilated too aggressively—or at all, if the patient is operated on while nearly awake. Another advantage of the lung replacement procedure is technical in nature, for example, when we need to access the bifurcation of the trachea during extensive cancer surgery. So if something is removed here, ventilation does not occur at that moment. Of course, a breathing tube can also be used here. Personally, I’m a ‘lazy’ surgeon and prefer to have as few tubes as possible in my surgical field so I can work on the patient undisturbed and minimize any moments of uncertainty during the procedure,” Dr. Redwan explains. 

In recent years, several technical advancements in lung replacement procedures have significantly improved intraoperative application and greatly increased patient safety. 

“One of the most significant recent innovations is the introduction of the twin-port cannula. This technology enables efficient gas exchange and optimized blood circulation via a single vascular access point. A special cannula is inserted into the body—either in the neck or the groin. Blood is drawn in through lateral openings and pumped to the artificial membrane, where gas exchange takes place outside the body. The blood is then returned to the same vessel via the cannula tip. This eliminates the need for a second cannula, as is customary in the traditional ECMO procedure. “Twin-port technology thus also improves safety and comfort for patients, and it allows us to operate much more easily and even achieve oxygenation thanks to what is known as apneic oxygenation, which makes it possible to maintain the oxygen content in the blood,” explains Dr. Redwan.

---

An interdisciplinary panel of experts is discussing the use of extracorporeal membrane oxygenation (ECMO) in critically ill patients. This team typically consists of intensive care physicians, cardiologists, thoracic and vascular surgeons, anesthesiologists, cardiac technicians, as well as nurses and physical therapists who specialize in ECMO.

---

The integration of portable ECMO devices into surgical and intensive care workflows has also increased flexibility in the operating room. These devices can be adapted to the specific requirements of a surgical procedure, which is particularly advantageous during complex thoracic surgeries. The improved ease of use of these systems allows the surgical team to focus more on the procedure itself, while lung support operates reliably in the background. 

The safe use of cannulas requires precise technique and experience, as improper handling can lead to complications. “It is possible for blood vessels to be damaged when inserting the cannulas, but this can be avoided by following the guidelines. This involves the classic Seldinger technique, which is used for venous access in surgery, anesthesia, and interventional radiology. Specific to this procedure is the risk of blood clot formation, which can be reduced by administering blood thinners (heparin). Bleeding and inflammatory reactions may also occur. Due to these potential risks, it is absolutely essential that these procedures be performed only by highly skilled professionals,” emphasizes Dr. Redwan.

The use of lung replacement procedures such as extracorporeal membrane oxygenation (ECMO) not only has an immediate impact on the course of the surgery but also influences postoperative rehabilitation and the long-term prognosis of patients with severe lung diseases. 

“If the lung replacement procedure is used during surgery, the prognosis is very good—based on my own experience with lung volume reduction surgery as well. This is because it helps reduce the potential risks associated with mechanical ventilation, and the entire procedure is also much gentler on the patient. Of course, surgical procedures can still be performed without a lung replacement procedure, but the advantages are undeniable, and I’m glad I became familiar with this method early on,” says Dr. Redwan, who also hopes for further improvements:

“It would be great if we could one day implant a completely artificial lung—and I believe we’re not that far from achieving that. There is a severe organ shortage—some patients wait five years or longer for a lung and, unfortunately, often die before they receive one. Patients who need a new heart are actually better off thanks to all the artificial heart systems available. We have an artificial lung at the hospital, but patients can’t go home with it. It would be great if we could support patients with a portable artificial lung system. Unfortunately, this isn’t possible yet due to space constraints, because membranes take up space. This is different from the heart, where everything can be kept small and compact. We don’t yet know how this can be implemented. However, many studies are underway, and I hope to see a positive outcome before I retire (in about 22 years). But I’m optimistic about it.” With this positive outlook, we conclude our conversation.

Thank you very much, Dr. Redwan, for this fascinating insight!