Cardiopulmonary bypass for advanced thoracic surgery

The review article by Fuentes-Gago et al. (1) describes in detail two cases of extended thoracic tumor resections with the help of cardio-pulmonary bypass. The authors nicely explain application and handling of the cardiopulmonary bypass.

Extracorporeal circulation may allow for extended resections and complete resections of locally advanced thoracic tumors in contact to or invading the heart or the great vessels. Without the possibility of resecting the affected cardiac or vascular structures en bloc the tumor remains not resectable or the resection is incomplete leaving tumor in place. In this respect, cardiopulmonary bypass is a very valuable tool for thoracic surgeons, because the circulatory support helps to realize complete and extended resections. For the fast majority of the malignancies encountered, a complete resection is the most important factor for the outcome of patients undergoing surgery.

Furthermore, cardio-pulmonary bypass is not only required for the resection of tumors infiltrating cardiac structures or the great vessels, but also helps to control severe bleeding and is a back-up tool for intraoperative bleeding complications und circulatory failure. It feels much safer to approach advanced tumors, when a cardio-pulmonary bypass is in stand-by. If things get more complicated than expected, or in case of an intraoperative crisis, the device can be life-saving (2,3).

Advanced tumors requiring extracorporeal circulation for resection are rare malignancies. It had been estimated, that less than 0.1% of all resections for lung cancer are done with cardiopulmonary bypass (3). In addition to T4 non-small cell lung carcinomas, sarcomas and a variety of locally advanced mediastinal and pleural tumors can be resected successfully with the help of this technique.

However, a word of caution is appropriate as cardiopulmonary bypass is associated with adverse effects and risks that have to be managed with great care to guarantee for a safe procedure. The surgical resection of a locally advanced thoracic tumor with cardiopulmonary bypass is indicated only in a minority of cases, because oncological principles for the treatment of the individual malignancy have to be respected (4-6). For advanced non-small cell lung cancer, satisfactory long-term survival has been demonstrated for pT4 and pN0/pN1 classifications. In case of advanced mediastinal lymph node disease or even distant metastasis (oligo-metastatic state), a radical surgical approach should be critically evaluated. For these advanced cancers, multimodal treatment regimens are generally accepted. Neo-adjuvant strategies should be considered, if appropriate. These may reduce the tumor mass, making the procedure easier in some of the cases. Further a neo-adjuvant therapy may reduce the risk for the development of subsequent metastases, and help to select the potential candidates for a radical surgical approach at restaging after therapy. Selection of candidates is the key for long-term success.

The article by Fuentes-Gago et al. (1) stresses the requirement of an extensive and careful planning of the multidisciplinary procedure. This includes additional preoperative evaluation including trans-esophageal echocardiography, cardiac MRT and in some cases cardiac catheterisation. The intraoperative approach and strategy should be discussed and planed in detail with alternatives. The tumor should be approached from a side allowing expose and control of the central cardiac and vascular structures. Excellent exposure by extended incisions is important for the resection of large tumor masses. The time on cardiopulmonary bypass should be kept as short as possible to avoid adverse effects. If possible, all preparations to isolate the tumor should be made prior to cardiopulmonary bypass to spare time on the device. Special attention has to be addressed to avoid postoperative bleeding complications under the anticoagulation regime. Peripheral cannulation requires experience to avoid complications. Cardiac arrest, cardioplegia and de-aering maneuvers have to be safe. Adverse effects and complications by cardio-pulmonary bypass further include an inflammatory reaction, capillary leak syndrome and lung injuries.

Currently a lot of emphasis is put into exploring minimal invasive procedures. Extended high-risk procedures are discussed more controversially and do not share the same popularity. Although cardio-pulmonary bypass has been a standard technique in cardiac surgery for more than 3 decades, only some patient series and some case reports were published in the literature during that time span. An extended resection with cardiopulmonary bypass remains a challenging and high-risk operation. However, several single case series demonstrated a low perioperative mortality and a long-term survival, not different from extended resections without cardiopulmonary bypass (5-8). For T4 non-small cell lung cancer a 5-year survival of more than 40% has been reported by several authors (5-8). The review by Rosskopfova et al. (7) summarizes relevant case series. In addition the recent experience by Dartevelle et al. (8) supports the favorable outcome and the acceptable long-term survival that has been achieved.

In addition to cardiopulmonary bypass, less invasive extracorporeal circulation techniques like extracorporeal membrane oxygenation (ECMO) have been used in recent years to help the thoracic surgeon to achieve advanced resections. ECMO-systems have different components and properties (7). They require only minimal anticoagulation, have less systemic adverse effects and can be used for much longer periods. However, they miss a reservoir for recollecting blood from the operating field. Over the last years, there has been a rapidly rising number of applied extracorporeal support devices for thoracic surgical procedures (9). For some indications the ECMO support in a veno-venous or veno-arterial setting is sufficient for an extended resection. The ECMO device is associated with less complication compared to a cardiopulmonary bypass. This has been shown for lung transplantation. The recent review by Rosskopfova et al. (7) gives a good overview on the indications and techniques of ECMO support and cardiopulmonary bypass for thoracic tumor resections.

The description of the two cases in the review (1) offers a lot of information on techniques and strategies in this situation. Because the application of cardiopulmonary bypass is not offered in all thoracic surgical units, but only in a minority of institutions, thoracic surgeons should be aware of the potential, indication and risks of this technique. Depending on the national education and training systems thoracic surgeons are more or less familiar with cardiopulmonary bypass techniques. The possibility of an extended resection for advanced thoracic malignancies should be evaluated by an experienced surgeon or in a specialized center. An intense interaction and cooperation with cardiac surgery is required to accomplish the best strategy for these patients. All thoracic surgeons should have at least a basic knowledge of extracorporeal circulation techniques und consider the application of the devices for a complete en bloc resection.

In conclusion, thoracic surgeons should be encouraged to use extracorporeal circulation support for advanced resections more frequently. Indeed, in the future a significant increase of thoracic tumor resections with circulatory support has to be expected. This implies improved interaction of thoracic and cardiac surgery as well as advanced training for thoracic surgeons. In many countries thoracic and cardiac surgeons have complete separate training programs. Therefore, it seems time to think about incorporation of cardio-pulmonary bypass and ECMO techniques into the training programs for thoracic surgeons.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned and reviewed by the Section Editor Jianfei Shen, MD (Department of Cardiothoracic Surgery, Taizhou Hospital of Zhejiang Province, Wenzhou Medical University, Taizhou, Zhejiang, China).

Conflicts of Interest: The author has completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/shc.2018.01.04). The author has no conflicts of interest to declare.

Ethical Statement: The author is accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Fuentes-Gago MG, Arnaiz-Garcia E, Gonzalez-Santos JM, et al. Cardiopulmonary bypass for extended resections. Shanghai Chest 2017;1:9. [Crossref]
2. Machuca TN, Cypel M, Keshavjee S. Cardiopulmonary Bypass and Extracorporeal Life support for Emergent Intraoperative Thoracic Situations. Thorac Surg Clin 2015;25:325-34. [Crossref] [PubMed]
3. Wiebe K. Extended pulmonary resections of advanced thoracic malignancies with support of cardiopulmonary bypass. Eur J Cardiothorac Surg 2006;29:571-7. [Crossref] [PubMed]
4. Reardon ES, Schrump DS. Extended resections of non-small cell lung cancers invading the aorta, pulmonary artery, left atrium, or esophagus: can they be justified? Thorac Surg Clin 2014;24:457-64. [Crossref] [PubMed]
5. Muralidaran A, Detterbeck FC, Boffa DJ, et al. Long-term survival after lung resection for non-small cell lung cancer with circulatory bypass: a systematic review. J Thorac Cardiovasc Surg 2011;142:1137-42. [Crossref] [PubMed]
6. Langer NB, Mercier O, Fabre D, et al. Outcomes After Resection of T4 Non-Small Cell Lung Cancer Using Cardiopulmonary Bypass. Ann Thorac Surg 2016;102:902-10. [Crossref] [PubMed]
7. Rosskopfova P, Perentes JY, Ris HB, et al. Extracorporeal support for pulmonary resection: current indications and results. World J Surg Oncol 2016;14:25. [Crossref] [PubMed]
8. Dartevelle PG, Mitilian D, Fadel E. Extended surgery for T4 lung cancer: a 30 years' experience. Gen Thorac Cardiovasc Surg 2017;65:321-8. [Crossref] [PubMed]
9. Rinieri P, Peillon C, Bessou JP, et al. National review of use of extracorporeal membrane oxygenation as respiratory support in thoracic surgery excluding lung transplantation. Eur J Cardiothorac Surg 2015;47:87-94. [Crossref] [PubMed]