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Operative Methods Used for Heart Transplantation in Complex Univentricular Heart Disease and Variations of Atrial Situs

2010; Elsevier BV; Volume: 15; Issue: 2 Linguagem: Inglês

10.1053/j.optechstcvs.2010.05.003

1532-8627

Jose Montalvo, Leonard L. Bailey,

Mechanical Circulatory Support Devices

Surgical versatility is the hallmark of successful heart transplantation in recipients with congenital heart disease (CHD), in whom cardiovascular anatomy is either naturally abnormal or has been altered by previous palliative operations.1Bailey L.L. Concepcion W. Shattuck H. et al.Method of heart transplantation for treatment of hypoplastic left heart syndrome.J Thorac Cardiovasc Surg. 1986; 92: 1-5PubMed Google Scholar, 2Chiavarelli M. Gundry S.R. Razzouk A.J. et al.Operative procedures for infant cardiac transplantation.in: Kapoor A.S. Laks H. Atlas of Heart-Lung Transplantation. McGraw-Hill, New York1994: 75-85Google Scholar, 3Vricella L.A. Razzouk A.J. del Rio M.J. et al.Heart transplantation for hypoplastic left heart syndrome: Modified technique for reducing circulatory arrest time.J Heart Lung Transplant. 1998; 12: 1167-1171Google Scholar, 4Bailey L.L. Heart transplantation techniques in complex congenital heart disease.J Heart Lung Transplant. 1993; 12: S168-S175PubMed Google Scholar, 5Razzouk A.J. Gundry S.R. Chinnock R.E. et al.Orthotopic transplantation for total anomalous pulmonary venous connection associated with complex congenital heart disease.J Heart Lung Transplant. 1995; 14: 713-717PubMed Google Scholar, 6Vricella L.A. Razzouk A.J. Gundry S.R. et al.Heart transplantation in infants and children with situs inversus.J Thorac Cardiovasc Surg. 1998; 116: 82-89Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar Factors affecting transplantation for CHD include the following: (1) anomalies of systemic or pulmonary venous connections; (2) hypoplasia or interruption of the aortic arch; (3) hypoplasia or surgically altered anatomy of the main and branch pulmonary arteries; (4) ambiguities of atrial situs; and (5) previous operative procedures, ie, Glenn cavopulmonary shunts, various Fontan connections, and atrial or arterial switch operations, that have rearranged systemic venous connections, pulmonary venous inflow, or pulmonary arterial anatomy. Both additional planning and additional time are required to accomplish the technical challenges of orthotopic heart transplantation in these recipients. This report addresses the surgical techniques used for transplantation of both pediatric and adult recipients with complex univentricular heart disease. Although transplantation is only occasionally employed as primary therapy for hypoplastic left heart syndrome in the current era, this type of CHD still serves as a model for orthotopic transplantation in any young infant with univentricular anatomy and accompanying aortic arch obstruction. Transplantation in recipients with atrial situs inversus totalis is also featured. Donor heart recovery for transplant reconstruction of complex CHD is tailored to the recipient's unique anatomy. Recovery may involve en bloc excision of the heart, the main and branch pulmonary arteries, the superior vena cava in continuity with the brachiocephalic vein, and portions of both internal jugular veins, and some, or all, of the aortic arch. Extraordinary requirements, such as these, are discussed with the on-site procurement agent in advance, because lung recovery may be threatened. It is always advisable to recover more cardiovascular tissue than is expected to be utilized during the transplant reconstruction. Once recovered, the graft is packaged, largely untrimmed, for transport. Detailed preparation of the graft is reserved for the moments just before implantation into the recipient. This is especially relevant if the recipient's pathologic anatomy is somewhat unclear before the surgical dissection. After donor median sternotomy, the thymus is removed and the innominate vein and its major tributaries are exposed and preserved, if they are needed, for en bloc recovery. If the recipient does not require reconstruction of systemic venous inflow, the innominate vein is doubly ligated and divided, thus facilitating access to the aortic arch and its branches. The head and arm vessels are double clipped or ligated and transected to gain access to the distal aortic arch and to the proximal descending aorta, which is exposed down to the first intercostal arteries. A silk tourniquet is placed loosely around the proximal descending aorta. The ductus or ligamentum arteriosum is divided between ligatures. The pericardium is then opened widely, and the heart is exposed. Both pleural cavities are broadly opened. When each organ procurement team is ready, heparin is administered, and a cardioplegia delivery catheter is placed in the ascending aorta. The inferior vena cava is divided, and either the left pulmonary veins are divided, or, if lung recovery is also being accomplished, the left atrium is opened widely. The donor is exsanguinated into the empty pleural spaces. After the heart empties, the proximal descending aorta is occluded with the tourniquet, and cold cardioplegic solution is administered by gravity infusion. The heart is bathed in ice-cold saline. Once the heart is cold and flaccid, excision is completed by transecting the superior vena cava (if no additional vein is needed), and either the right pulmonary veins are divided or, in the face of lung recovery, the left atriotomy incision is completed. The distal ascending aorta is clamped and divided either before or after the arch, depending on the need for recipient aortic arch reconstruction. If more superior vein is required, the innominate vein, with portions of internal jugular vein on either side, is removed en bloc with the superior vena cava and heart graft (Fig. 1). The heart, with its attached vessels, is removed and transferred to a basin of iced saline. A patent foramen ovale is sutured. “Back bench” preparation of the graft is left until just before implantation. No further graft perfusion is utilized until the recipient aortic clamp is removed. The operative strategy in recipients is one of deep hypothermia (18°C) and low-flow perfusion at 20 to 30 mL/kg/min.1Bailey L.L. Concepcion W. Shattuck H. et al.Method of heart transplantation for treatment of hypoplastic left heart syndrome.J Thorac Cardiovasc Surg. 1986; 92: 1-5PubMed Google Scholar, 2Chiavarelli M. Gundry S.R. Razzouk A.J. et al.Operative procedures for infant cardiac transplantation.in: Kapoor A.S. Laks H. Atlas of Heart-Lung Transplantation. McGraw-Hill, New York1994: 75-85Google Scholar, 3Vricella L.A. Razzouk A.J. del Rio M.J. et al.Heart transplantation for hypoplastic left heart syndrome: Modified technique for reducing circulatory arrest time.J Heart Lung Transplant. 1998; 12: 1167-1171Google Scholar Passive venous drainage is replaced with 1 or more flexible sucker drains. If arch reconstruction is required, the arterial catheter is advanced into either the right or the left carotid artery for selective cerebral perfusion at 10 mL/kg/min. Modest periods of circulatory arrest may also be utilized during implantation. As recipient and graft reperfusion begins, 10 mg/kg of lidocaine is administered to the recipient. Spontaneous recovery of a normal cardiac rhythm is expected during early rewarming. A nitroglycerin infusion is started at a dose of 0.5 μg/kg/min. Calcium gluconate, regardless of the recipient's size or weight, is given in the amount of 1 g (titrated slowly) when the core temperature reaches 30°C. Cardiopulmonary bypass is discontinued after a minimum of 60 minutes of reperfusion, and at a recipient temperature of about 36°C. A low-dose infusion of dopamine (3-5 μg/kg/min) may or may not be useful to stabilize the perioperative period. Primary closure of the sternotomy is the rule. Cardiopulmonary bypass is established in these young infants by means of an arterial cannula inserted into the distal main pulmonary artery and advanced well into the ductus arteriosus. A venous drainage catheter is placed into the systemic atrium. The arterial duct is snared as extracorporeal circulation is commenced (Fig. 2). The infant is cooled to 18-20°C, a process that usually requires 10 to 15 minutes, during which time the remainder of the aortic arch, arch vessels, and proximal descending aorta are exposed. Loose tourniquets are placed around each aortic arch vessel. Flow is reduced gradually to 20 to 30 mL/kg/min as hypothermia deepens. The hypoplastic ascending aorta is ligated and divided. The main pulmonary artery is clamped and divided, and the passive venous catheter is removed and replaced with a flexible active (sucker) catheter. The heart is excised, leaving posterior atrial cuffs intact (Fig. 3). Space is created for a large donor heart by excising that portion of the left pericardium that is anterior to the phrenic nerve. In the unusual instance of recipient atrial situs inversus, the anterior right-sided pericardium is also excised.Figure 3The main pulmonary artery has been clamped and the recipient's native heart has been removed. Low-flow deep hypothermic perfusion is continued using a flexible sucker positioned in the inferior vena cava. Graft implantation is commenced at the caudal end of the atrial septum, running up the septum and around the systemic atrium. Ao = aorta; IA = innominate artery; LA = left atrium; MPA = main pulmonary artery; PDA = patent ductus arteriosus; RA = right atrium; SVC = superior vena cava.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Graft-to-recipient atrial anastomoses are accomplished using 6-0 polypropylene suture, starting with the interatrial septum, followed by the systemic atrial free wall, and ending with the pulmonary atrium (Figure 3, Figure 4). The passive venous catheter is placed into the donor right atrium, by way of the appendage. The arch vessel snares are tightened, and circulatory arrest is established. The arterial cannula is withdrawn. The arterial duct is ligated and divided, and the undersurface of the hypoplastic aortic arch is opened, extending well onto the proximal descending aorta. Nearly but usually not quite all of the arterial duct tissue is removed. Alternatively, the region of the arterial duct is completely excised, and the proximal descending aorta is advanced cephalad and sutured separately to the opened distal aortic arch. At this point, the surgeon has an option to advance the arterial catheter of the extracorporeal circuit into one of the carotid arteries to institute “selective,” low-flow (10 mL/kg/min) cerebral perfusion. If this option is chosen, the proximal descending aorta will require cross-clamping. Because aortic arch reconstruction seldom requires more than 15 to 25 minutes, circulatory arrest provides a less cumbersome surgical environment with comparable neurologic safety. Arch reconstruction using circulatory arrest is illustrated in Figure 5. Following arch reconstruction, the aortic cannula is inserted into the neo-aortic arch, usually by way of the donor brachiocephalic artery stump, around which a purse-string suture is applied (Fig. 6). An ascending aortic vent site is opened, and air is displaced from the left-sided cardiovascular structures. Low-flow, hypothermic extracorporeal circulation is recommenced, and, finally, the aortic arch vessel tourniquets are released, starting with the left subclavian artery. If the pulmonary artery anastomosis appears uncomplicated, gradual rewarming is started. The pulmonary artery anastomosis is completed as illustrated in Figure 6. Low-flow hypothermic perfusion is continued for the duration of a complicated pulmonary artery reconstruction, and then rewarming is instituted.Figure 6Arch reconstruction is complete. The arterial perfusion cannula is re-inserted into the aorta by way of the donor brachiocephalic artery stump. A vent site is established. Perfusion is restarted after de-airing the left-sided structures. The arch vessel tourniquets are then removed, starting at the left subclavian artery. The pulmonary artery anastomosis is completed during rewarming. IA = innominate artery; MPA = main pulmonary artery.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Interruption of the aortic arch requires variation on the operative strategy, both for donor organ preparation and for implant reconstruction.4Bailey L.L. Heart transplantation techniques in complex congenital heart disease.J Heart Lung Transplant. 1993; 12: S168-S175PubMed Google Scholar A “Y” connector is placed in the arterial limb of the cardiopulmonary bypass circuit. The bifed arterial perfusion system is attached to 2 flexible arterial cannulae of equal diameter, usually 8 Fr, but possibly even 6 Fr in size. Both the native ascending aorta and the descending aorta (via the arterial duct) are cannulated and included in the cooling phase of extracorporeal circulation (Fig. 7A). Once cooling is accomplished and the atrial connections are completed, either circulatory arrest or low-flow “selective” cerebral circulation is used to facilitate arch reconstruction. A direct end-to-end distal aortic anastomosis is accomplished (Fig. 7B). An aberrant right subclavian artery is ligated and divided. An aberrant origin of the left subclavian artery is usually of little consequence. The recipient carotid arteries are anastomosed to the apex of the donor aortic arch as an onlay unit as illustrated in Figure 7C and D. During graft recovery for total anomalous pulmonary venous connection, the pulmonary veins are divided individually and oversewn, or simply ligated and divided.5Razzouk A.J. Gundry S.R. Chinnock R.E. et al.Orthotopic transplantation for total anomalous pulmonary venous connection associated with complex congenital heart disease.J Heart Lung Transplant. 1995; 14: 713-717PubMed Google Scholar A linear opening is created in the graft left atrium that corresponds to a longitudinal incision in the recipient's common pulmonary venous pool. The donor left atriotomy is anastomosed to the incision made in the recipient's common pulmonary venous pool as shown in Figure 8. The vascular connection between pulmonary veins and the systemic venous system (the so-called “vertical vein”) in extracardiac types of total anomalous pulmonary venous connection is ligated. The cavae are then connected, followed by the aorta, and, finally, the main pulmonary artery anastomosis completes the transplant. There are a number of technical alternatives for implantation of a situs solitus heart graft into a recipient with atrial situs inversus totalis. We prefer the method described by Vricella and coworkers.6Vricella L.A. Razzouk A.J. Gundry S.R. et al.Heart transplantation in infants and children with situs inversus.J Thorac Cardiovasc Surg. 1998; 116: 82-89Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar The donor graft is recovered en bloc with the entire right and left atria, superior vena cava and brachiocephalic vein, ascending aorta, and main pulmonary artery (Fig. 1). Atria are not incised at the procurement site, but the 2 divided left pulmonary veins are oversewn. Recipient deep hypothermia is established that allows for low-flow perfusion and a cold environment for the ischemic graft. The key in situs inversus is to position all anastomoses toward the midline. A generous cuff of recipient atrium is left attached to the left-sided inferior vena cava during excision of the native heart. The atrial cuff is rolled and approximated into a conduit in continuity with the inferior vena cava, thus extending the cava toward the right. The recipient's transected distal main pulmonary artery is oversewn from right to left, leaving an opening large enough for scissor tips. The recipient's left pulmonary artery is then opened from its origin to its distal portion to allow for an anastomosis to the donor main pulmonary artery (Fig. 9A). Graft implantation is achieved by opening the donor's pulmonary atrium between the 2 right pulmonary veins. The pulmonary atrial anastomosis is completed. The donor inferior vena cava is anastomosed end-to-end to the recipient's extended and diverted inferior vena cava. The neo-ascending aorta is shortened by excising redundant donor and recipient aortas. An end-to-end aortic anastomosis is performed, thus permitting graft reperfusion (Fig. 9B). The donor main pulmonary artery is anastomosed to the recipient's left pulmonary artery. Finally, the donor brachiocephalic vein is draped across the purposely shortened ascending aorta and is sutured to the recipient's left-sided superior vena cava as illustrated in Figure 9C. The recipient is kept hypothermic and in a low-flow state until the superior caval anastomosis is completed. Previous palliative surgery usually results in significantly altered recipient anatomy (Fig. 10A) and transplant reconstruction can be interesting (Fig. 10B).7del Nido P.J. Bailey L.L. Kirklin J.K. Surgical Techniques in Pediatric Heart Transplantation.in: Canter C.E. Kirklin J.K. ISHLT Monograph Series 2, Pediatric Heart Transplantation. Elsevier, Philadelphia2007: 83-102Google Scholar This is particularly true of the anatomic residuals following Norwood's staged reconstructive procedures, including cavopulmonary connections, and the various configurations of completion Fontan operations (Figs. 11). In each instance, the proximal cavae are preserved as useful anastomotic sites, as are the distal branch pulmonary arteries. Single arterial and venous cannulae are used to establish extracorporeal circulation. Low-flow deep hypothermia and active “sucker” venous drainage are used. The recipient's heart is excised, leaving behind a clamped, but open-ended aorta, distal pulmonary arteries, proximal systemic veins (cavae), and a pulmonary atrial cuff. Graft implantation starts with a pulmonary atrial anastomosis, followed by a series of end-to-end anastomoses in the following order: inferior vena cava, right and left pulmonary arteries, 1 or both superior vena cava(e) or internal jugular veins, and finally, the aorta.Figure 11(A) Standard Norwood stage I reconstruction for hypoplastic left heart syndrome. Central pulmonary arteries are fibrosed and stenotic. (B) Transplant reconstruction includes replacement of central pulmonary arteries with donor vessels recovered en bloc with the graft. The modified Blalock-Taussig shunt is divided. Donor aorta is anastomosed directly to the previously reconstructed aortic arch. A more extensive distal arch reconstruction may also be accomplished with donor aorta, if there is residual coarctation. a. = artery.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Outcomes for staged-palliative reconstruction of complex univentricular heart disease have improved significantly during the past 2 decades. Primary transplantation is now seldom utilized for these neonates and young infants. Nevertheless, the technical variations are worth remembering for the occasional infant who requires a primary transplant. Secondary, or salvage transplantation, with its technical challenges is increasing, and CHD is likely to remain a common indication for heart transplantation, whether primary or secondary, during the first decade of life. Over the past 25 years, the Loma Linda University Children's Hospital group has treated an array of patients with complex CHD using either primary or secondary transplantation. Graft survival curves for these 2 cohorts of patients, who have been transplanted since 1985, are presented in Figure 12. The complexity of secondary transplantation, including recipient presensitization from prior transfusion and use of allograft materials, translates into a graft survival disadvantage of about 15% compared with recipients of primary transplantation.