This arteriovenous device is driven by the cardiac pump function of the patient because no centrifugal pump is included. Thus, the precondition for the use of interventional lung assist (iLA) is a patient with uncompromised cardiac function. Percutaneous cannulation of the tubes is usually performed via the femoral artery and the femoral vein [3]. Central implantation via the pulmonary artery and the left atrium has been described for bridging of patients with pulmonary hypertension [4, 5]. The oxygenator has a low resistance and the priming volume is no more than 200 mL. Only part of the cardiac output is passing through the oxygenator membrane. Therefore, CO2 elimination can be sufficiently provided by an oxygenator flow of no more than 500–1000 mL/min [6]. Oxygenation would require a flow of at least 2000 mL/min. An interventional assist device is shown in Fig. 13.2. The major advantage of this device is the low priming volume. However, this device is mainly used for CO₂ removal.

The precondition for the insertion of this device is a hemodynamically stable patient with no relevant pulmonary hypertension. Venovenous ECMO can guarantee for sufficient gas exchange (CO₂ elimination and oxygenation) at flow rates up to 4000 mL/min. Standard cannulation drains the blood via the right femoral vein from the vena cava inferior and recirculates the blood via the right jugular vein to the right atrium. Sufficient distance between the cannulas is essential to avoid recirculation of the blood in the oxygenator.

The venoarterial ECMO is a rather invasive form of extracorporeal device. The blood is drained from the right atrium pumped through the oxygenator and recirculated via a large systemic artery (Fig. 13.1). By means of this technique, hemodynamic support is provided and the circulation through the lung is substantially reduced. Cannulation can be performed via the right atrium and the ascending aorta for exclusively intraoperative use and via the femoral vein (drainage of blood from the right atrium) and the femoral artery (recirculation of oxygenated blood) for prolonged postoperative use. The tip of the arterial cannula is situated in the descending aorta. Thus, the cardiac output from the heart (gas exchange through patient’s lung) and the recirculated blood from the venoarterial ECMO mix in the descending aorta. This fact may lead to substantially different oxygenation in the upper and lower part of the body. Monitoring of oxygenation has to be performed on the right arm because it is most likely to achieve similar values compared to the cerebral oxygenation.

This extracorporeal support is exclusively used during surgery. The patient has to be fully heparinized for the use of this device. Therefore, surgical bleeding is a feared complication associated with the use of the heart-lung machine. Additionally, it should not be used for oncological procedures because systemic spread of tumor cells should be avoided in these patients.

The indications for the use of an extracorporeal device in lung surgery are displayed in Table 13.2. Basically the pre-, intra-, and postoperative use of an extracorporeal device can be necessary due to pulmonary malfunction (impaired gas exchange), cardiac malfunction (right and/or left ventricular failure), or a mixture of both. The crucial question for all situations with the need for an extracorporeal @device is will the situation improve after surgery? Or in other words: Can medical and/or surgical treatment improve the underlying organ malfunction to an extent that the patient can be successfully weaned from the extracorporeal device after a reasonable time span?