Hypoplastic left heart syndrome: What's next?
2015; Elsevier BV; Volume: 151; Issue: 4 Linguagem: Inglês
10.1016/j.jtcvs.2015.12.032
ISSN1097-685X
AutoresHarold M. Burkhart, Jess L. Thompson, Timothy J. Nelson,
Tópico(s)Congenital Diaphragmatic Hernia Studies
ResumoCentral MessageManagement strategies for hypoplastic left heart syndrome are evolving and will include standard surgical and hybrid techniques as well as cell-based therapies.See Articles page 1112 and page 424 in the February issue.See Editorial Commentary page 1123. Management strategies for hypoplastic left heart syndrome are evolving and will include standard surgical and hybrid techniques as well as cell-based therapies. See Articles page 1112 and page 424 in the February issue. See Editorial Commentary page 1123. During the past 4 decades, the field of congenital cardiac surgery has made remarkable strides in the care of patients with complex congenital cardiac anomalies. The care of neonates with hypoplastic left heart syndrome (HLHS) has received a great deal of attention with management strategies evolving and early surgical results improving.1Iannettoni M.D. Bove E.L. Mosca R.S. Lupinetti F.M. Dorostkar P.C. Ludmirsky A. Improving results with first stage palliation for hypoplastic left heart syndrome.J Thorac Cardiovasc Surg. 1994; 107: 934-940PubMed Google Scholar Despite the incredible progress that has been made in managing these complex patients, the 5-year transplant-free survival remains around 50%. Poor cardiac function and pulmonary architecture are issues that result in a less-than-perfect Fontan patient contributing to this less-than-ideal survival. In this issue of the Journal, the 2 largest single-center experiences with the hybrid approach for HLHS are presented. Both institutions champion the advantages of the hybrid approach; controlling pulmonary artery blood flow and systemic circulation while avoiding cardiopulmonary bypass and extensive cardiac reconstruction during the neonatal period. Yerebakan and colleagues2Yerebakan C. Valeske K. Elmontaser H. Yörüker U. Mueller M. Thul J. et al.Hybrid therapy for hypoplastic left heart syndrome: myth, alterntive, or standard?.J Thorac Cardiovasc Surg. 2016; 151: 1112-1123Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar present their 17-year surgical experience with 126 patients managed with a hybrid single-ventricle strategy. The overall surgical results are exceptional with low mortality reported at each stage. Galantowicz and Yates3Galantowicz M. Yates A. Improved outcomes with the comprehensive stage 2 procedure after an initial hybrid stage 1.J Thorac Cardiovasc Surg. 2016; 151: 424-429Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar discuss their comprehensive experience with the comprehensive stage 2 procedure after a hybrid stage 1 procedure. By instituting protocols to help control the risk factors (eg, pulmonary artery thrombosis, emergent operation, and age) for the challenging comprehensive stage 2 procedure, they are able to significantly decrease mortality. These articles are significant in that they demonstrate the HLHS hybrid pathway can be expected to be very successful in the hands of experienced, high-volume centers. Although the articles2Yerebakan C. Valeske K. Elmontaser H. Yörüker U. Mueller M. Thul J. et al.Hybrid therapy for hypoplastic left heart syndrome: myth, alterntive, or standard?.J Thorac Cardiovasc Surg. 2016; 151: 1112-1123Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar, 3Galantowicz M. Yates A. Improved outcomes with the comprehensive stage 2 procedure after an initial hybrid stage 1.J Thorac Cardiovasc Surg. 2016; 151: 424-429Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar provide important insight to the successful management of these patients with a hybrid strategy, it is important to remember that there is clearly a learning curve, with very few centers reporting this caliber of results. Issues with appropriate pulmonary artery band tightening and ductal stent positioning are of continued concern—not to mention the occasional problem of retrograde aortic arch obstruction. In addition, having bands around the branch pulmonary arteries for months can create problems negatively influencing a patient's Fontan candidacy. After comprehensive stage 2 procedure, both groups report significant issues with pulmonary artery architecture necessitating further intervention. Because innovation leads to innovation, it is clear that the hybrid strategy is evolving as well. In an effort to have the early advantages of the hybrid stage 1 procedure while avoiding the disadvantages of the comprehensive stage 2 procedure, some institutions are reporting the successful use of a rapid 2-stage Norwood procedure in selected or all patients with HLHS.4Davies R. Radtke W. Bhat M. Baffa J. Woodford E. Pizarro C. Hybrid palliation for critical systemic outflow obstruction: neither rapid stage 1 Norwood nor comprehensive stage 2 mitigate consequences of early risk factors.J Thorac Cardiovasc Surg. 2015; 149: 182-193Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar, 5DiBardino D. Gomez-Arostegui J. Kemp A. Raviendran R. Hegde S. Devaney E.J. et al.Intermediate results of hybrid versus primary Norwood operation.Ann Thorac Surg. 2015; 99: 2141-2149Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar, 6Ota N. Murata M. Tosaka Y. Ide Y. Tachi M. Ito H. et al.Is routine rapid-staged bilateral pulmonary artery banding before stage 1 Norwood a viable strategy?.J Thorac Cardiovasc Surg. 2014; 148: 1519-1525Abstract Full Text Full Text PDF PubMed Scopus (25) Google Scholar This strategy involves bilateral pulmonary artery banding while using prostaglandins for ductal patency. After 2 to 3 weeks, after any concerning issues have resolved, a Norwood procedure is performed. Although this strategy was likely initially used as a salvage procedure to offer care to newborn infants deemed unfit for a Norwood procedure, the use of this approach has expanded. There are numerous benefits to the strategy of palliating before Norwood palliation. It offers a relatively quick technique to aid patients who present in cardiogenic shock while avoiding cardiopulmonary bypass and, hopefully, mechanical support. The same goes for those presenting with concerns of infection. In addition, it allows time to sort out any concerning extracardiac issues or syndromes. As these varying hybrid strategies evolve, 1 thing is evident: A surgeon will need to be familiar with all the options to successfully progress and improve surgical outcomes. As surgical strategies evolve and result in a higher rate of HLHS survival, other therapies will have to be used to improve the long-term outlook. Regenerative strategies that include cell-based therapeutics offer a new adjunctive approach to augment surgical repair of HLHS. In contrast to the relatively quiescence of adult cardiac tissues, which retain only a 1% turnover rate annually, fetal myocardium retains a robust regenerative capacity that decreases in the first months to years of life.7Bergmann O. Bhardwaj R.D. Bernard S. Zdunek S. Barnabé-Heider F. Walsh S. et al.Evidence for cardiomyocyte renewal in humans.Science. 2009; 324: 98-102Crossref PubMed Scopus (2262) Google Scholar, 8Amir G. Ma X. Reddy V.M. Hanley F.L. Reinhartz O. Ramamoorthy C. et al.Dynamics of human myocardial progenitor cell populations in the neonatal period.Ann Thorac Surg. 2008; 86: 1311-1319Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar, 9Rupp S. Bauer J. von Gerlach S. Fichtlscherer S. Zeiher A.M. Dimmeler S. et al.Pressure overload leads to an increase of cardiac resident stem cells.Basic Res Cardiol. 2012; 107: 252Crossref PubMed Scopus (28) Google Scholar Notably, animal studies demonstrate a remarkable capacity of cardiac tissue to dramatically respond to injury within the first few postnatal days. This innate regenerative capacity is further supported by the observation that human cardiac progenitor cells decrease 10-fold to adult levels within 2 to 4 weeks postnatal. In fact, pressure overload in the right ventricle in pediatric hearts results in a 3-fold increase in cardiac stem cells and indicates that an adaptive response is present in youth. Therefore, the clinical application of regenerative strategies provides new avenues for therapeutic benefit.10Selem S.M. Kaushal S. Hare J.M. Stem cell therapy for pediatric dilated cardiomyopathy.Curr Cardiol Rep. 2013; 15: 369Crossref PubMed Scopus (21) Google Scholar, 11Bernstein H.S. Srivastava D. Stem cell therapy for cardiac disease.Pediatr Res. 2012; 71: 491-499Crossref PubMed Scopus (87) Google Scholar The role of cell-based therapies in HLHS has been significantly bolstered in 2015. The initial case reports suggested that children with heart failure might benefit from intracoronary bone marrow-derived mononuclear cell delivery; this included a child with HLHS.12Rupp S. Jux C. Bönig H. Bauer J. Tonn T. Seifried E. et al.Intracoronary bone marrow cell application for terminal heart failure in children.Cardiol Young. 2012; 22: 558-563Crossref PubMed Scopus (39) Google Scholar, 13Rupp S. Bauer J. Tonn T. Schächinger V. Dimmeler S. Zeiher A.M. et al.Intracoronary administration of autologous bone marrow-derived progenitor cells in a critically ill two-yr-old child with dilated cardiomyopathy.Pediatr Transpl. 2009; 13: 620-623Crossref PubMed Scopus (45) Google Scholar, 14Rupp S. Zeiher A.M. Dimmeler S. Tonn T. Bauer J. Jux C. et al.A regenerative strategy for heart failure in hypoplastic left heart syndrome: intracoronary administration of autologous bone marrow-derived progenitor cells.J Heart Lung Transplant. 2010; 29: 574-577Abstract Full Text Full Text PDF PubMed Scopus (45) Google Scholar The first 1-year follow-up for a pediatric cohort was published with dilated cardiomyopathy patients who received bone marrow stem cells. The patients showed significant improvement in left ventricle ejection fraction within 6 months that was stable for at least 12 months.15Bergmane I. Lacis A. Lubaua I. Jakobsons E. Erglis A. Follow-up of the patients after stem cell transplantation for pediatric dilated cardiomyopathy.Pediatr Transplant. 2013; 17: 266-270Crossref PubMed Scopus (26) Google Scholar The first clinical trial for HLHS using cell-based therapy was completed in Japan with a 3-year follow-up on 7 patients. This study demonstrated the safety and feasibility of intracoronary infusion of cardiac-derived autologous cells. The study also suggested a therapeutic benefit compared with a control group with sustained improvement in right ventricle ejection fraction after 36 months.16Tarui S. Ishigami S. Ousaka D. Kasahara S. Ohtsuki S. Sano S. et al.Transcoronary infusion of cardiac progenitor cells in hypoplastic left heart syndrome: three-year follow-up of the Transcoronary Infusion of Cardiac Progenitor Cells in Patients with Single-Ventricle Physiology (TICAP) trial.J Thorac Cardiovasc Surg. 2015; 150: 1198-1208Abstract Full Text Full Text PDF PubMed Scopus (81) Google Scholar In addition to coronary infusions, we17Burkhart H. Qureshi M.Y. Peral S.C. O'Leary P.W. Olson T.M. Cetta F. et al.Regenerative therapy for hypoplastic left heart syndrome: first report of intraoperative intramyocardial injection of autologous umbilical-cord blood-derived cells.J Thorac Cardiovasc Surg. 2015; 149: e35-e37Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar reported the first case of intramyocardial injections of autologous cells derived from umbilical cord blood for a patient with HLHS. This approach maintains the use of autologous cell types to avoid any potential alloantibody formation and aims to optimize the myocardial response to increased workloads at the time of stage II surgery. The goal of these studies should be to improve right ventricle performance and prevent subsequent Fontan failures by early intervention. Leveraging the technologies available today to augment cardiac function with low-cost and readily accessible tools should be a priority throughout the innovation process. Engaging payers into the process as early as possible with a focus on improved outcomes will further accelerate the development of these emerging cell-based regenerative technologies. Hybrid therapy for hypoplastic left heart syndrome: Myth, alternative, or standard?The Journal of Thoracic and Cardiovascular SurgeryVol. 151Issue 4PreviewThis retrospective study presents our operative results, mortality, and morbidity with regard to pulmonary artery growth and reinterventions on the pulmonary artery and aortic arch, including key features of our institutional standards for the 3-stage hybrid palliation of patients with hypoplastic left heart syndrome. Full-Text PDF Open ArchiveImproved outcomes with the comprehensive stage 2 procedure after an initial hybrid stage 1The Journal of Thoracic and Cardiovascular SurgeryVol. 151Issue 2PreviewTo report our improving institutional experience with the hybrid alternative surgical strategy for the management of hypoplastic left heart syndrome, in which hybrid stage 1 is followed by a comprehensive stage 2 procedure (removal of patent ductus arteriosus stent and pulmonary artery [PA] bands, aorta and PA reconstruction, Damus–Kaye–Stansel, atrial septectomy, Glenn). Full-Text PDF Open ArchiveHybrid therapy for hypoplastic left heart syndrome: Myth, alternative, or standard—neither Minotaur nor MidasThe Journal of Thoracic and Cardiovascular SurgeryVol. 151Issue 4PreviewThe development of a hybrid procedure for palliation of hypoplastic left heart syndrome (HLHS) was prompted by limited early success of the Norwood procedure.1,2 The hybrid procedure—stenting of the arterial duct combined with banding of the pulmonary arteries (PAs) and atrial septectomy—appeared to reawaken some of the presumed errors of early pediatric cardiac surgery; for example, bilateral PA banding, and seemed contrary to the trend toward earlier aggressive reparative neonatal cardiac surgery. Full-Text PDF Open Archive
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