Effect of right ventricular anatomy on the cardiopulmonary response to exercise. Implications for the Fontan procedure

Incorporation of the right ventricle (RV) into the pulmonary circulation of patients with tricuspid atresia undergoing a Fontan procedure has been advocated. The consequences of this approach on the exercise function of these patients was studied by examining the effects of progressive and steady-state bicycle exercise tests performed by 11 patients with right atrial (RA)-RV Fontan anastomoses, seven patients with RA-pulmonary artery (PA) Fontan anastomoses, 13 patients after repair of tetralogy of Fallot, and 34 normal control patients. All patients were in New York Heart Association class I. The exercise function of the patients undergoing RA-RV and RA-PA Fontan procedures were similar. The achieved peak work loads 60% and 67% of control and peak oxygen consumptions 60% and 64% of control, respectively. Both groups also displayed excessive ventilation, elevated dead space/tidal volume ratios, and depressed cardiac output during steady-state exercise. In contrast, tetralogy of Fallot patients achieved peak work loads and oxygen consumptions 83% of control and maintained normal cardiac outputs and dead space/tidal volume ratios during steady-state exercise. These results suggest that the presence of an RV within the pulmonary circulation of the Fontan patient does not result in improved exercise function. This may be due to the development of obstructive gradients across the RA-RV conduits during exercise or to the RV's negative effect on left ventricular compliance. Moreover, in contrast with the postoperative tetralogy of Fallot patient, the hypoplastic RV of tricuspid atresia may not have sufficient myocardium to assume the active pumping function required by exercise.     

Older Age at Completion of Fontan Procedure Is Associated with Improved Percentage of Predicted Maximum Oxygen Uptake

We tested the hypothesis that later completion of the Fontan procedure is associated with improved exercise capacity in the current period of staged single-ventricle palliation. We performed a retrospective study, in Fontan patients, of exercise stress test data from April 2003 through March 2011. Patients were included if they had received staged palliations in accordance with current surgical strategy, defined as the performance of a superior cavopulmonary connection at ≤1 year of age, followed in subsequent years by Fontan completion. Patients with a pacemaker or respiratory exchange ratio <1 were excluded. Early and late Fontan groups were created on the basis of whether Fontan completion had been performed at <4 or ≥ 4 years of age. The primary predictor variable was age at Fontan completion, and the primary marker of exercise performance was the percentage of predicted maximum oxygen consumption. During the study period, 55 patients were identified (mean age, 11.7 ± 2.8 yr).Older age at Fontan completion correlated positively with higher percentages of predicted maximum oxygen consumption (R=0.286, P=0.034). Patients in whom Fontan completion was performed at ≥4 years of age had higher percentages of predicted maximum oxygen consumption than did those in whom completion was at <4 years of age (84.4 ± 21.5 vs 72.9 ± 18.1; P=0.041). Later Fontan completion might be associated with improved exercise capacity in patients palliated in accordance with contemporary surgical strategy.     

Is the "perfect Fontan" operation routinely achievable in the modern era?

OBJECTIVE: In 1990, Fontan, Kirklin, and colleagues published equations for survival after the so-called "Perfect Fontan" operation. After 1988, we evolved a protocol using an internal or external polytetraflouroethylene tube of 16 to 19 millimetres diameter placed from the inferior caval vein to either the right or left pulmonary artery along with a bidirectional cava-pulmonary connection. The objective of this study was to test the hypothesis that a "perfect" outcome is routinely achievable in the current era when using a standardized surgical procedure. METHODS: Between 1 January, 1988, and 12 December, 2005, 112 patients underwent the Fontan procedure using an internal or external polytetraflouroethylene tube plus a bidirectional cava-pulmonary connection, the latter usually having been constructed as a previous procedure. This constituted 45% of our overall experience in constructing the Fontan circulation between 1988 and 1996, and 96% of the experience between 1996 and 2005. Among all surviving patients, the median follow-up was 7.3 years. We calculated the expected survival for an optimal candidate, given from the initial equations, and compared this to our entire experience in constructing the Fontan circulation. RESULTS: An internal tube was utilized in 61 patients, 97% of whom were operated prior to 1998, and an external tube in 51 patients, the latter accounting for 95% of all operations since 1999. At 1, 5, 10 and 15 years, survival of the entire cohort receiving polytetraflouroethylene tubes is superimposable on the curve calculated for a "perfect" outcome. Freedom from replacement or revision of the tube was 97% at 10 years.CONCLUSION: Using a standardized operative procedure, combining a bidirectional cavopulmonary connection with a polytetraflouroethylene tube placed from the inferior caval vein to the pulmonary arteries for nearly all patients with functionally univentricular hearts, early and late survival within the "perfect" outcome as predicted by the initial equations of Fontan and Kirklin is routinely achievable in the current era. The need for late revision or replacement of the tube is rare.     

Cardiorespiratory response to exercise after definitive repair of univentricular atrioventricular connection

To characterize the exercise hemodynamic responses after definitive operation for patients with univentricular atrioventricular connection, we compared the cardiorespiratory response to exercise of 4 patients who had undergone the ventricular septation procedure and 9 patients who had undergone the Fontan operation with that of 38 patients who had univentricular atrioventricular connection but had not undergone definitive operation. Exercise duration and total work increased significantly after the Fontan procedure but not after the septation operation. Rest or exercise (or both) ventilation improved significantly after the septation operation but less so after the Fontan operation. Blood oxygen saturation (rest and exercise) improved significantly after either procedure. Cardiac output and stroke-volume response to exercise remained abnormal in both groups of patients after operation. Although definitive operation for univentricular atrioventricular connection results in improved cardiorespiratory function at rest and exercise, these variables remain abnormal when compared with those of normal subjects.     

Growth of children with a functionally single ventricle following palliation at moderately increased altitude

The bidirectional Glenn and Fontan procedures are empirically performed as interim and definitive procedures in children with a functionally single ventricle. The optimal stage of palliation, nonetheless, remains unknown. During childhood, growth is a fundamental measure of response to therapy. Growth may be influenced by the degree of cyanosis, the volume load on the ventricle, and cardiac performance. Thus, the weight and stature of children with a functionally single ventricle who underwent a bidirectional Glenn procedure or a Fontan procedure were studied to determine the effect of each intervention on growth. Z scores for weight and stature were retrospectively determined prior to palliation, at yearly intervals for 4 years, and from long-term measurements until 18 years of age in all patients with at least 2 years of observation following palliation. Growth was evaluated in 54 patients with a bidirectional Glenn procedure, and 65 patients with a Fontan procedure. The Z scores for weight were improved after each method of surgical palliation. Stature, however, was improved only following the bidirectional Glenn procedure. Growth was impaired in patients who developed protein losing enteropathy. Weight improved only during the initial 2 years after the Fontan procedure in patients who had a surgical fenestration. Over the long-term, patients who underwent a Fontan procedure were more likely to have a Z score less than -2.0 for weight and stature than patients who underwent only a bidirectional Glenn procedure. Late mortality and the incidence of heart transplantation were increased in patients who experienced a decrease in their rate of growth, defined as a negative change of more than one Z score in weight or stature, following the Fontan procedure. In conclusion, at moderately increased altitude, children with a functionally single ventricle grow more appropriately following the bidirectional Glenn procedure than following the Fontan procedure. A decrease in the rate of growth is associated with a poor prognosis following the Fontan procedure.     

Course of tricuspid atresia in the Fontan era

Tricuspid atresia is an uncommon form of congenital heart disease and long-term survival was rare before the Fontan era. It was thought that the long-term survival of patients with tricuspid atresia would be improved by the introduction of the Fontan procedure and its subsequent modifications. This study reviews the clinical course of 84 patients with tricuspid atresia identified in the first year of life in the Fontan era. Prior palliative operations, their results and their ultimate application for the Fontan procedure were considered. Eleven patients died before surgical intervention and 5 did not undergo catheterization or echocardiographic confirmation before death. Five children underwent the Fontan procedure without prior palliation and 1 child does not require palliation at the present time. Sixty-seven patients (80%) had surgical procedures before evaluation for the suitability of a Fontan operation. Thirty-four patients had a second surgical palliation and 9 patients had a third palliation. The surgical mortalities for the first, second and third palliative surgery were 17.9, 17.6 and 0%, respectively. Thirty-two patients (38%) underwent the Fontan procedure and 2 deaths occurred (6%). An estimate of the probability of surviving for 1 year was 64% (95% confidence limits 54 to 74%) and that of 8 years was 55% (95% confidence limits 44 to 66%).     

Factors influencing survival of patients with heterotaxy syndrome undergoing the Fontan procedure.

OBJECTIVES. This study was undertaken to determine those factors that may influence survival in patients with heterotaxy syndrome undergoing the Fontan procedure. BACKGROUND. The Fontan procedure remains the preferred palliative procedure for patients with heterotaxy syndrome. Although the mortality rate has improved for patients without this syndrome undergoing the Fontan procedure, it remains high for patients with heterotaxy syndrome. METHODS. The medical records of 20 consecutive pediatric patients with asplenia (n = 12) and polysplenia (n = 8) who underwent the Fontan procedure between January 1, 1986 and December 31, 1990 were reviewed. Anatomic and hemodynamic data were collected, as well as data on types of surgical palliative procedures and on outcome of the Fontan procedure. RESULTS. There were two early and two late deaths for a total mortality rate of 20% in the patients with heterotaxy syndrome, as compared with 8.5% for the patients without this syndrome who underwent the Fontan procedure during the same time period. Factors that significantly increased the risk of the Fontan procedure in these patients were 1) preoperative findings of greater than mild atrioventricular valve regurgitation, b) hypoplastic pulmonary arteries, and c) mean pulmonary artery pressure greater than or equal to 15 mm Hg after 6 months of age. Systemic and pulmonary venous anomalies coupled with single-ventricle anatomy were not significant risk factors for determining a poor outcome of the Fontan procedure. CONCLUSIONS. This study suggests that the outcome of the Fontan procedure in patients with heterotaxy syndrome may be improved by early protection of the pulmonary vascular bed, despite the existence of other cardiac anomalies.     

Reopening of persistent left superior caval vein after bidirectional cavopulmonary connections

Persistent left superior vena cava (SVC) is a not uncommon finding in patients with congenital heart disease. This anatomical variant must be recognised before doing a Glenn anastomosis, bidirectional cavopulmonary connection or a Fontan-type procedure. Following these procedures, reopening of a left SVC leading to clinical cyanosis can occur. Five cases are described in whom persisting left SVCs were excluded before performing a bidirectional cavopulmonary connection or Fontan procedure but (re-)opened after surgery, leading to cyanosis either by reducing effective pulmonary blood flow (bidirectional cavopulmonary connection) or by an obligatory right to left shunt (Fontan). These observations suggest that, embryologically, the lumen of the left SVC obliterates rather than disappears. Balloon occlusion angiography of the innominate vein before cavopulmonary connections or Fontan procedures might improve detection of these collateral vessels.

Keywords: persistent left superior vena cava; cavopulmonary connection; Fontan procedure; congenital heart disease     

Orthotopic heart transplantation in patients with univentricular physiology

Parallel advancements in surgical technique, preoperative and postoperative care, as well as a better understanding of physiology in patients with duct-dependent pulmonary or systemic circulation and a functional single ventricle, have led to superb results in staged palliation of most complex congenital heart disease (CHD) [1]. The Fontan procedure and its technical modifications have resulted in markedly improved outcomes of patients with single ventricle anatomy [2,3,4]. The improved early survival has led to an exponential increase of the proportion of Fontan patients surviving long into adolescence and young adulthood [5]. Improved early and late survival has not yet abolished late mortality secondary to myocardial failure, therefore increasing the referrals for cardiac transplantation [6]. Interstage attrition [7] is moreover expected in staged palliation towards completion of a Fontan-type circulation, while Fontan failure represents a growing indication for heart transplantation [8]. Heart transplantation has therefore become the potential "fourth stage" [9] or a possible alternative to a high-risk Fontan operation [10] in a strategy of staged palliation for single ventricle physiology. Heart transplant barely accounts for 16% of pediatric solid organ transplants [11]. The thirteenth official pediatric heart transplantation report- 2010 [11] indicates that pediatric recipients received only 12.5% of the total reported heart transplants worldwide. Congenital heart disease is not only the most common recipient diagnosis, but also the most powerful predictor of 1-year mortality after OHT. Results of orthotopic heart transplantations (OHT) for failing single ventricle physiology are mixed. Some authors advocate excellent early and mid-term survival after OHT for failing Fontan [9], while others suggest that rescue-OHT after failing Fontan seems unwarranted [10]. Moreover, OHT outcome appears to be different according to the surgical staging towards the Fontan operation and surgical technique of Fontan completion [12].The focus of this report is a complete review of the recent literature on OHT for failing single ventricles, outlining the clinical issues affecting Fontan failure, OHT listing and OHT outcome. These data are endorsed reporting our experience with OHT for failing single ventricle physiology in recent years.     

三尖瓣下移畸形的外科治疗(附24例报告)

手术纠治三尖瓣下移畸形24例，死亡4例（16．67％）。合并畸形或病变有房、室间隔缺损、预激综合征、心包炎。行房化心室折叠术18例，三尖瓣替换术6例。作者认为随着手术方法、心肌保护和体外循环技术不断改进，手术指征应较过去放宽。手术治疗的关键是房化心室的折叠和三尖瓣关闭不全的纠正。术中注意避免损伤传导束和冠状血管。对功能右心室极小的重型三尖瓣下移畸形，术后易发生难以纠正的右心衰竭，死亡率高，以选择改良Fontan手术或全腔静脉与肺动脉连接术为宜。行三尖瓣替换的人工瓣膜以选择生物辩为宜。     

Surgical considerations of univentricular heart with total anomalous pulmonary venous connection

Out of the 600 patients undergoing univentricular repair during the last 11 years, 20 children had associated total anomalous pulmonary venous connection. The objective was to outline the clues to establish the diagnosis of this rare disease combination and the various surgical options available to manage the same. Bidirectional Glenn, bilateral bidirectional Glenn, total cavopulmonary connection and atriopulmonary connection were performed in combination with rechannelling of various types of total anomalous pulmonary venous connection in 20 children aged 6 months to 36 months (mean +/- SD 17.65 +/- 9.02 months). Diagnosis could be established pre-operatively in only 13 (65%) patients. Out of 6 early deaths (30%), 4 were directly attributable to missed diagnosis. No late deaths occurred over a follow-up period ranging from 1 month to 132 months. None of the surviving children required reoperation and all are in NYHA functional class I. Doppler echocardiography of the surviving children revealed unrestricted atrio/cavopulmonary anastomosis and pulmonary vein to atrium connection in all survivors. Our own experience, coupled with a review of the literature, indicates that a missed diagnosis increases the hospital mortality. Cross sectional 2D echocardiography is a superior method of detection of associated total anomalous pulmonary venous connection compared to angiocardiography. Exclusion of the diagnosis of anomalous pulmonary venous connection is imperative in all univentricular hearts pre-operatively and on operation table. Failure to recognise this disease combination results in formation of a closed systemic circuit after bidirectional Glenn or a modified Fontan of connection and is lethal as happened in our early experience. It is suggested that one-stage Fontan operation should be performed only if other criteria for Fontan procedure are satisfied.     

Considerations in Critical-Care and Anesthetic Management of Adult Patients Living With Fontan Circulation

The Fontan procedure is a staged palliation for various complex congenital cardiac lesions, including tricuspid atresia, pulmonary atresia, hypoplastic left heart syndrome, and double-inlet left ventricle, all of which involve a functional single-ventricle physiology. The complexity of the patients’ original anatomy combined with the anatomic and physiologic consequences of the Fontan circulation creates challenges. Teens and adults living with Fontan palliation will need perioperative support for noncardiac surgery, peripartum management for labour and delivery, interventions related to their structural heart disease, electrophysiology procedures, pacemakers, cardioversions, cardiac surgery, transplantation, and advanced mechanical support. This review focuses on the anesthetic and intensive care unit (ICU) management of these patients during their perioperative journey, with an emphasis on the continuity of preintervention planning, referral pathways, and postintervention ICU management. Requests for recipes and doses of medications are frequent; however, as in normal anesthesia and ICU practice, the method of anesthesia and dosing are dependent on the presenting medical/surgical conditions and the underlying anatomy and physiologic reserve. A patient with Fontan palliation in their early 20s attending school full-time with a cavopulmonary connection is likely to have more reserve than a patient in their late 40s with an atriopulmonary Fontan at home waiting for a heart transplant. Each case will require an anesthetic and critical care plan tailored to the situation. The critical care environment is a natural extension of the anesthetic management of a patient, with complex considerations for a patient with Fontan palliation.     

Long-term anticoagulation therapy and thromboembolic complications after the Fontan procedure

BACKGROUND: The necessity for chronic anticoagulation of Fontan patients remains controversial. We determined the prevalence of thromboembolic complications after the Fontan procedure in relation to different long-term anticoagulation strategies. METHODS: The clinical outcomes, postoperative anticoagulation strategies and occurrence of thromboembolic complications in 102 ethnic Chinese patients who had undergone Fontan procedure between 1980 and 2002 were reviewed. RESULTS: The early and late surgical mortalities, all unrelated to thromboembolism, were 10.8% (11/102) and 5.8% (6/104), respectively. Of the 85 survivors, 46 (54%) were maintained on long-term warfarin therapy, 8 (9%) on aspirin prophylaxis while 31 (37%) were not on chronic anticoagulation. Four (4.5%) patients, two with and two without warfarin prophylaxis, developed thromboembolic complications at 0.14 to 7.7 years after the Fontan procedure (0.74%/patient-year). Three had a grossly dilated right atrium after atriopulmonary connection, two of whom had atrial fenestrations. The other had atrial tachycardia. Freedom from development of thromboembolic complications (mean+/-S.E.) at 1, 5 and 10 years after surgery was 97+/-19%, 96+/-2.5% and 92+/-4.2%, respectively. When compared with those on long-term warfarin therapy, patients without chronic anticoagulation were followed-up longer (p=0.001), more likely to have undergone atriopulmonary connection (p<0.001), less likely to have fenestrations (p=0.02) and cardiac arrhythmias (p=0.02) but not predisposed to increased risk of thromboembolism (p=1.00). CONCLUSION: The study supports the contention that chronic anticoagulation may not be required for majority of ethnic Chinese Fontan patients. Nonetheless, it may perhaps be considered in those with grossly dilated right atrium, cardiac arrhythmias and residual right-to-left shunts.     

Single-stage versus two-stage modified Fontan procedure

We compared surgical outcomes of the single-stage and two-stage modified Fontan procedures to clarify clinical superiority. Of 28 children undergoing a modified Fontan procedure from October 1995 to October 2005, 15 had a 1-stage and 13 had a 2-stage operation. In the 2-stage group, pulmonary artery growth was evaluated before and after the first stage. Operative mortality was 26.6% in the 1-stage group and 0% in the 2-stage group. The benefits of a previous bidirectional Glenn shunt were decreased cyanosis and volume overload, but there was no significant difference in pulmonary artery growth reflected in pulmonary artery indices before and after the bidirectional Glenn procedure. Older children underwent a 2-stage modified Fontan procedure and had better outcomes in terms of lower mortality, improved oxygen saturation, decreased volume load, and less deterioration of atrioventricular valve regurgitation.     

Pediatric cardiac surgery

The surgical literature continues to report numerous successful series of neonatal correction for a variety of complex cardiac defects. Infant repair of defects, such as those of the atrioventricular canal, tetralogy of Fallot (with or without pulmonary atresia), truncus arteriosus, and transposition of the great arteries, is now considered routine, and in most instances, the results of infant correction surpass those of staged procedures. The use of palliative bands and shunts is consequently receiving less attention in the literature, although the selection of these procedures remains an important option for certain uncorrectable defects. The success of Norwood's operation for hypoplastic left-heart syndrome has encouraged application of major staging procedures as an appropriate therapeutic modality for certain complex defects as a stage towards eventual performance of the Fontan procedure. The Fontan procedure itself seems to show improved results with caval-pulmonary anastomoses, and the use of a bidirectional Glenn shunt or a hemi-Fontan procedure as a stage towards total Fontan physiology is gaining increased popularity. Aortic and pulmonary homografts have changed the technical options for patients with aortic valve disease as well as for infants with truncus arteriosus and tetralogy of Fallot with pulmonary atresia. Although surgeons continue to focus on optimal methods of neonatal myocardial protection, more attention is being given to perfusion techniques that protect the brain and organism as a whole. The use of intraoperative echocardiography has enhanced the standard of evaluation of operative repair so that fewer patients now leave the operating room with poor outcome. The outlook for patients born with congenital heart defects in 1992 continues to improve with enhanced applications of technology and operative technique.     

Influence of ventricular morphology on aerobic exercise capacity in patients after the Fontan operation

OBJECTIVES: This study investigated the influences of ventricular morphology, hemodynamics and clinical findings on exercise capacity in patients after the Fontan operation. BACKGROUND: Determinants of exercise capacity after the Fontan operation remain unclear. METHODS: Peak oxygen uptake (PVo2) was determined in 105 patients by exercise test and compared to hemodynamics and clinical findings. Patients were divided into three groups based on ventricular morphology: those with a right ventricle (group RV), a biventricle (group BV) and a left ventricle (group LV). RESULTS: Ten patients with atrioventricular valve regurgitation (AVVR) or hypoxia exhibited a low PVo2. After excluding these patients, although PVo2 did not correlate with hemodynamics, except ventricular ejection fraction (p < 0.02), it correlated with age at the Fontan operation and exercise test (p < 0.002). The PVo2 was higher in group LV (63+/-9%) than in groups RV (55+/-9%) and BV (55+/-12%) (p < 0.01), while an inverse correlation between PVo2 and age at operation was demonstrated only in group RV (p < 0.05). Groups RV or BV and age at exercise test were associated with a lower PVo2, whereas group LV was an independent predictor of a higher PVo2 (p < 0.01). During 4.2 years of follow-up, a decrease in peak heart rate was related to a decrease in PVo2 (p < 0.05). The PVo2 decreased in group RV (p < 0.01). CONCLUSIONS: In addition to AVVR, hypoxia, and heart rate response, ventricular morphology is related to exercise capacity. Early Fontan operation may be beneficial in terms of exercise capacity, especially in the group RV patients.     

12th Annual C. Walton Lillehei Memorial Lecture in Cardiovascular Surgery: Fontan conversion--the Chicago experience

Between 1994 and 2011, we performed 133 Fontan conversions with arrhythmia surgery. Most patients had tricuspid atresia or double-inlet left ventricle with prior atriopulmonary connection. Operative mortality was 1.5%, and mean length of stay was 14 days. A total of eight patients (6%) have had late cardiac transplantation. Freedom from arrhythmia recurrence is 85% at 10 years. For properly selected patients with a functionally univentricular heart who have had an atriopulmonary Fontan procedure, Fontan conversion with arrhythmia surgery significantly improves quality of life.     

A Single Institution’s Experience with Later Extracardiac Fontan Procedure Off Bypass

Purpose: To summarize Fontan procedure data from our institution, UCSF Benioff Children’s Hospital Oakland, in order to better understand outcomes of our surgical and post-operative care. Basic Procedures: This is a retrospective cross-sectional chart review summarizing characteristics and outcomes of patients who underwent the Fontan procedure at our institution between 2005 and 2016. Main Findings: Sixty-five Fontan procedures were performed at our institution between 2005 and 2016, all of which were extracardiac Fontan procedures performed by the same surgical team. At the time of Fontan procedure, the mean patient age was 56.4 ± 18.7 months and mean weight was 16.6 ± 2.7 kg. There was no significant correlation appreciated between patient age/weight and outcomes. Six (9%) Fontan conduits were fenestrated. Thirty-eight (58%) Fontan procedures were performed off cardiopulmonary bypass. Fontan procedures performed off bypass and of shorter duration were associated with fewer days to extubation and pressor discontinuation post-operatively, as well as higher discharge SpO2. Two patients (3%) required Fontan conduit takedown during their post-operative ICU stays. The most common complications were pleural effusion, chylothorax, arrhythmia and infection. There was no early or late mortality. Principle Conclusions: Delayed extracardiac Fontan procedure off cardiopulmonary bypass appears to be a safe and effective approach. The strategy may provide benefit when considering certain outcomes, however more studies are needed to further elucidate these findings.     

The Fontan operation in infants less than 2 years of age.

Young age remains a reported risk factor for a successful Fontan operation despite improved survival rates. Since March 1978, the Fontan operation has been performed in 47 patients. To avoid a primary or secondary palliative shunt, an early Fontan procedure (Group 1: mean age 1.5 +/- 0.5 years, range 0.6 to 2) has been performed in 17 children with the outcome similar to that of the remaining 30 older patients (Group 2: mean age 7.5 +/- 5 years, range 2.4 to 23 years). Preoperatively both groups had acceptable hemodynamic status for a successful Fontan result. Operative variables including cardiopulmonary bypass time, aortic cross-clamp time and core temperature were similar between groups and did not affect mortality. The postoperative mortality rate including early surgical (0% vs. 13%, respectively), late (18% vs. 12%) and total (18% vs. 23%) was similar between Groups 1 and 2 (p greater than 0.05). Immediate postoperative arrhythmias were more frequent in Group 1 (71% vs. 25%, p less than 0.01) with no related mortality, while late arrhythmias occurred with equal frequency (29% vs. 39%, p greater than 0.05). Group 1 infants required a longer hospital stay (22 +/- 9 vs. 14 +/- 5 days, p less than 0.01). Thus, young age is not a risk factor for successful outcome of the Fontan operation in patients with acceptable preoperative hemodynamic status. An early Fontan operation may also avoid prolonged palliative procedures and their potential deleterious effects.