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Operative Techniques and Pitfalls in Donor Heart-Lung Procurement
Operative Techniques and Pitfalls in Donor Heart-Lung Procurement M. Salna, Y. Shudo, and Y.J. Woo* Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA
ABSTRACT Background. Heart-lung transplantation is a well-established therapeutic modality for concomitant end-stage heart and lung failure. With growing organ scarcity, the rates of these transplants are declining, and center experience is waning. Methods. With over 35 years of experience performing heart-lung transplantation, we describe our procurement protocol herein, as well as offer suggestions to avoid potential pitfalls in order to ensure technical excellence in harvesting these valuable grafts. Results. Procurement issues most commonly arise with organ preservation and inadvertent damage to structures that are difficult to fully visualize. Conclusions. En-bloc heart-lung procurement can be taught effectively and safely to trainees with an emphasis on avoiding common pitfalls that may compromise graft function.
T
HE first heart-lung transplant was performed by Bruce Reitz in 1981 at Stanford Hospital, utilizing techniques developed by Norman Shumway in the 1960s [1]. Since then, nearly 4000 patients with end-stage heart and/or lung disease have received en-bloc heart-lung grafts [2]. Stanford University Hospital has the longest history of performing these combined transplants, and performed 7 in 2017 alone. Heart-lung transplantation provides a meaningful therapeutic option to those with combined heart and lung failure. In this article, we describe our procurement methodology, share common pitfalls learned from experience, and offer suggestions to prevent injury or compromise graft function. MATERIALS AND METHODS En-bloc Heart-Lung Procurement Upon arrival at the procurement center, flexible bronchoscopy is performed to evaluate for airway lesions or purulent collections. The patient is maintained on 100% fraction of inspired oxygen during procurement with pressures of at least 350 mmHg. After pre-oxygenation, a median sternotomy is performed and the bilateral pleura are opened, ensuring the lungs are wellprotected during dissection. Each lobe is examined for damage and palpated for edema, nodules, or other pathology which may have recently developed or not been appreciated on imaging. A Valsalva maneuver is applied to ensure all lobes inflate well and the pericardial cavity is opened. Cardiac dissection begins by partially dissecting the ascending aorta off the main pulmonary artery (mPA) to allow for safe ª 2018 Elsevier Inc. All rights reserved. 230 Park Avenue, New York, NY 10169
Transplantation Proceedings, 50, 3111e3112 (2018)
manipulation of the aorta. The superior vein cava (SVC) is partially dissected off the right pulmonary artery (PA). During SVC dissection, the azygos vein is identified and doubly ligated but not transected, as an azygos vein injury can cause considerable, difficultto-control, bleeding. Finally, the inferior vena cava is isolated circumferentially to achieve sufficient length. Systemic heparinization is then instituted with 30,000 units, an antegrade cardioplegia cannula is inserted into the aorta, de-aired, and connected to a hypothermic systemic perfusion line. The mPA is cannulated with a 22-french EOPA 3-D dispersion tipped cannula (Medtronic, Minneapolis, Minn, United States). It is critical that the procurement team place this cannula into the proximal mPA to ensure equal perfusion of both PAs to reduce the risk of primary graft dysfunction associated with inadequate preservate administration. Following canula placement, 500 mg of alprostadil (0.5 mg/mL) is administered into the mPA to transiently reduce pulmonary vascular resistance. The SVC is then clamped above the azygos vein (ensuring the central venous catheter has been withdrawn) and the left atrial appendage tip generously excised to vent the left ventricle. The inferior vena cava (IVC) is also partially divided at this time and the aortic cross-clamp applied. Hypothermic antegrade cardioplegia with UW solution and pulmonoplegia with Perfadex (XVIVO, Gothenburg, Sweden) are then infused through the aorta
*Address correspondence to Y. Joseph Woo, MD, 300 Pasteur Drive, Falk Cardiovascular Research Center, Stanford University School of Medicine, Stanford, CA 94305. Tel: 650-725-3828; Fax: 650-725-3846. E-mail: [email protected] 0041-1345/18 https://doi.org/10.1016/j.transproceed.2018.06.009
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SALNA, SHUDO, AND WOO The lungs are then insufflated and the trachea stapled off. Of note, we apply our peak inspiratory pressures depending on the method of transportation. If using ground transportation, we inflate the lungs with 30 mmHg. If traveling by air, we inflate to 25 mmHg to avoid over-inflation in atmospheric pressure with cruising altitude. The heart-lung bloc is then removed from the thoracic cavity, inspected for injury and pathology (Fig 1), and placed in preservate solution in sealed bags with ice within a cooler.
CONCLUSIONS
Fig 1. Procured heart-lung en-bloc. and PA, respectively, and ice slush is placed into the chest cavity for topical cooling (with frequent reinstallation). Care must be taken to ensure the PA cannula is not displaced during slush insertion or manipulation of the heart. The aortic root pressure is periodically checked by palpitation as is the efflux from the left atrial appendage and inferior vena cava to ensure adequate cardioplegia and pulmonoplegia. Shigemura et al described inadequate perfusion techniques as one of the most prevalent errors in lung transplant procurement, as trainees rush to simply initiate cold-perfusion rather than continually ensuring adequate cannula positioning and bilateral PA perfusion [3]. Once cardioplegia and pulmonoplegia are completed, the aortic cross-clamp, cardioplegia line, and pulmonoplegia cannulas are removed. The IVC is transected and dissected to the level of the right atrium, remaining mindful of the nearby coronary sinus and right inferior pulmonary vein. This is followed by transection of SVC cephalad to the azygos vein with creation of an innominate cuff and ascending aorta transection distal to the innominate artery origin. Dissection of the posterior pericardial cavity is then completed in a cephalad fashion using blunt dissection with a supinated hand. The trachea is gently dissected off the esophagus manually, as sharp instrumentation in this area can damage the tracheal posterior membrane. In liberating the bilateral lungs from the pericardium, care must be taken to avoid injury to the left PA as well as the right mainstem bronchus as this can easily be injured with overly aggressive dissection owing to its acute caudal angle.
In this report we have described the heart-lung procurement technique performed at Stanford University Hospital with the goal of standardizing organ procurement and preservation techniques to minimize primary graft dysfunction. Currently, there are an estimated 86 centers globally performing heart-lung transplantations with 54 (63%) reporting an average of 1 procedure per year since 2009 [2]. This decline in volume portends further decline in annual volume as centers lose experience with performing these procedures, jeopardizing future care of patients with concomitant end-stage pulmonary disease and right ventricular failure. The goal of this article is to provide insight into our procurement strategy to facilitate centers in continuing to offer heart-lung transplant as a therapeutic option in these complex patients. With the growing scarcity of organs, technical excellence is the imperative first step in optimizing graft success in the recipient. ACKNOWLEDGMENTS We thank Mr Paul Chang for his excellent technical assistance.
REFERENCES [1] Reitz BA, Wallwork JL, Hunt SA, et al. Heart-lung transplantation: successful therapy for patients with pulmonary vascular disease. N Engl J Med 1982;306:557e64. [2] Chambers DC, Yusen RD, Cherikh WS, et al. The Registry of the International Society for Heart and Lung Transplantation: thirty-fourth adult lung and heart-lung transplantation report-2017; focus theme: allograft ischemic time. J Heart Lung Transplant 2017;36:1047e59. [3] Shigemura N, Bhama J, Nguyen D, et al. Pitfalls in donor lung procurements: how should the procedure be taught to transplant trainees? J Thorac Cardiovasc Surg 2009;138:486e90.
ABSTRACT Background. Heart-lung transplantation is a well-established therapeutic modality for concomitant end-stage heart and lung failure. With growing organ scarcity, the rates of these transplants are declining, and center experience is waning. Methods. With over 35 years of experience performing heart-lung transplantation, we describe our procurement protocol herein, as well as offer suggestions to avoid potential pitfalls in order to ensure technical excellence in harvesting these valuable grafts. Results. Procurement issues most commonly arise with organ preservation and inadvertent damage to structures that are difficult to fully visualize. Conclusions. En-bloc heart-lung procurement can be taught effectively and safely to trainees with an emphasis on avoiding common pitfalls that may compromise graft function.
T
HE first heart-lung transplant was performed by Bruce Reitz in 1981 at Stanford Hospital, utilizing techniques developed by Norman Shumway in the 1960s [1]. Since then, nearly 4000 patients with end-stage heart and/or lung disease have received en-bloc heart-lung grafts [2]. Stanford University Hospital has the longest history of performing these combined transplants, and performed 7 in 2017 alone. Heart-lung transplantation provides a meaningful therapeutic option to those with combined heart and lung failure. In this article, we describe our procurement methodology, share common pitfalls learned from experience, and offer suggestions to prevent injury or compromise graft function. MATERIALS AND METHODS En-bloc Heart-Lung Procurement Upon arrival at the procurement center, flexible bronchoscopy is performed to evaluate for airway lesions or purulent collections. The patient is maintained on 100% fraction of inspired oxygen during procurement with pressures of at least 350 mmHg. After pre-oxygenation, a median sternotomy is performed and the bilateral pleura are opened, ensuring the lungs are wellprotected during dissection. Each lobe is examined for damage and palpated for edema, nodules, or other pathology which may have recently developed or not been appreciated on imaging. A Valsalva maneuver is applied to ensure all lobes inflate well and the pericardial cavity is opened. Cardiac dissection begins by partially dissecting the ascending aorta off the main pulmonary artery (mPA) to allow for safe ª 2018 Elsevier Inc. All rights reserved. 230 Park Avenue, New York, NY 10169
Transplantation Proceedings, 50, 3111e3112 (2018)
manipulation of the aorta. The superior vein cava (SVC) is partially dissected off the right pulmonary artery (PA). During SVC dissection, the azygos vein is identified and doubly ligated but not transected, as an azygos vein injury can cause considerable, difficultto-control, bleeding. Finally, the inferior vena cava is isolated circumferentially to achieve sufficient length. Systemic heparinization is then instituted with 30,000 units, an antegrade cardioplegia cannula is inserted into the aorta, de-aired, and connected to a hypothermic systemic perfusion line. The mPA is cannulated with a 22-french EOPA 3-D dispersion tipped cannula (Medtronic, Minneapolis, Minn, United States). It is critical that the procurement team place this cannula into the proximal mPA to ensure equal perfusion of both PAs to reduce the risk of primary graft dysfunction associated with inadequate preservate administration. Following canula placement, 500 mg of alprostadil (0.5 mg/mL) is administered into the mPA to transiently reduce pulmonary vascular resistance. The SVC is then clamped above the azygos vein (ensuring the central venous catheter has been withdrawn) and the left atrial appendage tip generously excised to vent the left ventricle. The inferior vena cava (IVC) is also partially divided at this time and the aortic cross-clamp applied. Hypothermic antegrade cardioplegia with UW solution and pulmonoplegia with Perfadex (XVIVO, Gothenburg, Sweden) are then infused through the aorta
*Address correspondence to Y. Joseph Woo, MD, 300 Pasteur Drive, Falk Cardiovascular Research Center, Stanford University School of Medicine, Stanford, CA 94305. Tel: 650-725-3828; Fax: 650-725-3846. E-mail: [email protected] 0041-1345/18 https://doi.org/10.1016/j.transproceed.2018.06.009
3111
3112
SALNA, SHUDO, AND WOO The lungs are then insufflated and the trachea stapled off. Of note, we apply our peak inspiratory pressures depending on the method of transportation. If using ground transportation, we inflate the lungs with 30 mmHg. If traveling by air, we inflate to 25 mmHg to avoid over-inflation in atmospheric pressure with cruising altitude. The heart-lung bloc is then removed from the thoracic cavity, inspected for injury and pathology (Fig 1), and placed in preservate solution in sealed bags with ice within a cooler.
CONCLUSIONS
Fig 1. Procured heart-lung en-bloc. and PA, respectively, and ice slush is placed into the chest cavity for topical cooling (with frequent reinstallation). Care must be taken to ensure the PA cannula is not displaced during slush insertion or manipulation of the heart. The aortic root pressure is periodically checked by palpitation as is the efflux from the left atrial appendage and inferior vena cava to ensure adequate cardioplegia and pulmonoplegia. Shigemura et al described inadequate perfusion techniques as one of the most prevalent errors in lung transplant procurement, as trainees rush to simply initiate cold-perfusion rather than continually ensuring adequate cannula positioning and bilateral PA perfusion [3]. Once cardioplegia and pulmonoplegia are completed, the aortic cross-clamp, cardioplegia line, and pulmonoplegia cannulas are removed. The IVC is transected and dissected to the level of the right atrium, remaining mindful of the nearby coronary sinus and right inferior pulmonary vein. This is followed by transection of SVC cephalad to the azygos vein with creation of an innominate cuff and ascending aorta transection distal to the innominate artery origin. Dissection of the posterior pericardial cavity is then completed in a cephalad fashion using blunt dissection with a supinated hand. The trachea is gently dissected off the esophagus manually, as sharp instrumentation in this area can damage the tracheal posterior membrane. In liberating the bilateral lungs from the pericardium, care must be taken to avoid injury to the left PA as well as the right mainstem bronchus as this can easily be injured with overly aggressive dissection owing to its acute caudal angle.
In this report we have described the heart-lung procurement technique performed at Stanford University Hospital with the goal of standardizing organ procurement and preservation techniques to minimize primary graft dysfunction. Currently, there are an estimated 86 centers globally performing heart-lung transplantations with 54 (63%) reporting an average of 1 procedure per year since 2009 [2]. This decline in volume portends further decline in annual volume as centers lose experience with performing these procedures, jeopardizing future care of patients with concomitant end-stage pulmonary disease and right ventricular failure. The goal of this article is to provide insight into our procurement strategy to facilitate centers in continuing to offer heart-lung transplant as a therapeutic option in these complex patients. With the growing scarcity of organs, technical excellence is the imperative first step in optimizing graft success in the recipient. ACKNOWLEDGMENTS We thank Mr Paul Chang for his excellent technical assistance.
REFERENCES [1] Reitz BA, Wallwork JL, Hunt SA, et al. Heart-lung transplantation: successful therapy for patients with pulmonary vascular disease. N Engl J Med 1982;306:557e64. [2] Chambers DC, Yusen RD, Cherikh WS, et al. The Registry of the International Society for Heart and Lung Transplantation: thirty-fourth adult lung and heart-lung transplantation report-2017; focus theme: allograft ischemic time. J Heart Lung Transplant 2017;36:1047e59. [3] Shigemura N, Bhama J, Nguyen D, et al. Pitfalls in donor lung procurements: how should the procedure be taught to transplant trainees? J Thorac Cardiovasc Surg 2009;138:486e90.