Outcomes Along the Fontan Pathway Neonatal Palliation Patients undergoing staged palliation for fUVH are at high risk for mortality Even seemingly simple procedures such as pulmonary artery banding carry a hospital mortality of 7%.228 Similarly, construction of a modified BlalockTaussig systemic-to-pulmonary artery shunt has a mortality of 6.7%, and a central shunt has a risk of 7.7%.228 The Norwood procedure for fUVH with systemic outflow obstruction is among the highest-risk neonatal procedures routinely performed today Among programs with a strong interest in this subset of patients, there are reports of survival greater than 95% in certain subgroups.304–307 The results are attributed to the improvements and innovations in care covered in this chapter The Single Ventricle Reconstruction Trial provided a chance to see contemporary outcomes of the Norwood procedure among experienced centers One-year survival was only 63.6% for those randomized to a systemic-to-pulmonary artery shunt and 73.7% among those who received the right ventricle-to-pulmonary artery conduit.308 Recent data from the Society of Thoracic Surgeons Congenital Heart Database shows Norwood survival has improved Among more than 100 congenital heart programs in the United States and Canada, the hospital survival for the Norwood procedure has reached 86.3%.228 Current Interstage Results Improvements in neonatal palliation of patients with fUVH revealed the increased risk of the interstage period—the time from initial palliation to the second stage, SCPC Even the well-palliated individual with fUVH continues to have physiologic risks, specifically a multidistribution circulation, volume overload to the single ventricle, and cyanosis Increased physiologic vulnerability may be due to the development of recurrent lesions, such as shunt stenosis or arch obstruction, or intercurrent illness that will result in an imbalance in the oxygen supply-demand relationship Finally, the challenges of heart failure with cyanosis can result in growth failure Home monitoring using, initially, periodic pulse oximetry to identify excessive cyanosis and scales to identify growth failure and acute dehydration was developed to identify the at- risk patient before catastrophic collapse.309 Using these strategies, some programs have nearly eliminated interstage mortality.310 The National Pediatric Cardiology Quality Improvement Collaborative targeted reduction of interstage mortality and has demonstrated a significant reduction from 9.5% to 5.3%.244 Current Results of the Second Stage or Superior Cavopulmonary Connection Historically the SCPC has been a low-risk procedure; indeed, the first report of the Society of Thoracic Surgeons Congenital Heart Database identified 73 patients with hypoplastic left heart syndrome undergoing the superior cavopulmonary anastomosis with no mortality.311 However, with identification of the interstage period as one of sustained risk, the age of SCPC has decreased both as an effort to decrease the period of interstage vulnerability and as a strategy for the management of patients who fail after neonatal palliation of fUVH Overall this strategy appears to be successful in decreasing interstage mortality Data from National Pediatric Cardiology Quality Improvement Collaborative demonstrated lower interstage mortality among centers that performed SCPC at less than 5 months (5.7 vs 9.9 months) with no difference in SCPC survival, complications, or hospital length of stay.238 However, earlier SCPC as a strategy for the patient deemed to be at high risk during the interstage period is of questionable benefit Meza and colleagues analyzed the Single Ventricle Reconstruction Trial dataset and found that among low- or average-risk infants, SCPC between 3 and 6 months post-Norwood was associated with maximal 3-year transplant-free survival.230 In high-risk patients—specifically those with right ventricular dysfunction, those that required ECMO after stage 1 palliation or had lower weight for age— z-score did not benefit from earlier SCPC The Single Ventricle Reconstruction Trial found the hospital mortality to be 4.3% and the median hospital length of stay 8 days Risk factors for mortality were non-elective SCPC, moderate or greater AV valve regurgitation, and the need for AV repair.201 The most recent Society of Thoracic Surgeons Congenital Heart database report shows an overall mortality of 1.8% for all patients undergoing the SCPC over the last 4 years.228 Current Fontan Results In the era of staged single palliation of fUVH, the perioperative outcomes of the Fontan are excellent This is likely due to combination of better neonatal palliation and early volume unloading with the SCPC as well as improved Fontan candidate selection Several recent series numbering hundreds of patients demonstrate a mortality of 0.4% to 4.0%.296,312–316 The most recent Society of Thoracic Surgeons database report shows a Fontan mortality between 0.5% and 1.2%.317 Despite improvements in acute outcome for the Fontan, it is noteworthy that longitudinal results show significant attrition along the pathway from neonate to Fontan Data from the Single Ventricle Reconstruction Trial show a 6-year transplant-free survival of only 59% for the Norwood with a Blalock-Taussig shunt and 64% for the right ventricle-to-pulmonary artery conduit.318 A recent analysis of the Australian and New Zealand Fontan Registry, which includes 683 adult survivors, provides perspective on the long-term outcome The registry includes 201 atriopulmonary connections and 482 total cavopulmonary connections (249 lateral tunnels and 233 extracardiac conduits) Overall survival was good; 90% at 30 years of age and 80% at 40 years of age, but survival at age 30 years was significantly worse for the patients with atriopulmonary connections (P = 03) There was significant late functional impairment, with only 53% of patients in New York Heart Association functional class I Only 41% of Fontan patients were free of serious adverse events at 40 years of age Arrhythmias were found in 136 (20%), 42 (6%) had received a permanent pacemaker, 45 (7%) had had a thromboembolic event, and 135 (21%) required a surgical reintervention.319 ...risk patient before catastrophic collapse.309 Using these strategies, some programs have nearly eliminated interstage mortality.310 The National Pediatric Cardiology Quality Improvement Collaborative targeted reduction of interstage mortality and has demonstrated a significant reduction from 9.5% to 5.3%.244... Overall this strategy appears to be successful in decreasing interstage mortality Data from National Pediatric Cardiology Quality Improvement Collaborative demonstrated lower interstage mortality among centers that