Early and late results of the modified Fontan procedure for double-inlet left ventricle: the Mayo Clinic experience

EASL-ERN position paper on liver involvement in patients with Fontan-type circulation

Fontan-type surgery is the final step in the sequential palliative surgical treatment of infants born with a univentricular heart. The resulting long-term haemodynamic changes promote liver damage, leading to Fontan-associated liver disease (FALD), in virtually all patients with Fontan circulation. Owing to the lack of a uniform definition of FALD and the competitive risk of other complications developed by Fontan patients, the impact of FALD on the prognosis of these patients is currently debatable. However, based on the increasing number of adult Fontan patients and recent research interest, the European Association for The Study of the Liver and the European Reference Network on Rare Liver Diseases thought a position paper timely. The aims of the current paper are: (1) to provide a clear definition and description of FALD, including clinical, analytical, radiological, haemodynamic, and histological features; (2) to facilitate guidance for staging the liver disease; and (3) to provide evidence- and experience-based recommendations for the management of different clinical scenarios.

27 years of experience with the Fontan procedure: characteristics and clinical outcomes of children in a tertiary referral hospital

BACKGROUND

The Fontan operation has improved the survival of children born with congenital heart disease with single ventricle physiology. The most widely adopted variations of the Fontan procedure are the extracardiac conduit, the lateral tunnel ve the intra/extracardiac conduit with fenestration. Despite advances in the treatment and prevention of early and late complications that may develop after Fontan surgery, morbidity still remains an important problem.

METHODS

304 patients who underwent Fontan surgery in our center between 1995 and 2022 were included in our study. The complications that developed in patients who underwent primary Fontan or lateral tunnel surgery and extracardiac conduit Fontan application were compared.

RESULTS

Classic Fontan surgery and lateral tunnel surgery were performed in 26 of the patients, and extracardiac Fontan surgery was performed in 278 patients. 218 of 304 cases were patients with single ventricular pathology. 86 cases were patients with two ventricular morphologies but complex cardiac pathology. Fenestration was performed in only 6 patients, other patients did not require fenestration. The mean follow-up period of our patients was 12 years (3 months-27 years). When the complications between Fontan procedures were compared in our study, it was found that the length of hospital stay and mortality were statistically significantly reduced in patients who underwent extracardiac Fontan surgery. There was no significant difference in terms of complications that can be seen after Fontan surgery and the length of stay in the intensive care unit.

CONCLUSION

Fontan complex is a palliative surgery for children with complex heart disease. Palliative surgical operations aimed at the preparation of the Fontan circulation lead to the preparation of the pulmonary vascular bed and the preservation of ventricular function. The techniques applied in Fontan surgery affect the early and long-term complications and the survival of the patients. In our study, when we examined the patients who extracardiac conduit Fontan procedure for the non-cardiac route, we found that mortality and morbidity were minimal.

Platelet count and abdominal dynamic CT are useful in predicting and screening for gastroesophageal varices after Fontan surgery

OBJECTIVE

Patients who undergo Fontan surgery for complex cardiac anomalies are prone to developing liver and gastrointestinal complications. In particular, gastroesophageal varices (GEVs) can occur, but their prevalence is unknown. We aimed to elucidate the occurrence of GEVs and the predicting parameters of GEVs in these patients.

MATERIALS AND METHODS

Twenty-seven patients (median age, 14.8 years; median time since surgery, 12.9 years) who had undergone the Fontan surgery and were examined by abdominal dynamic computed tomography (CT) for the routine follow-up were included in the study. Radiological findings including GEVs and extraintestinal complications were retrospectively evaluated by experienced radiologists in a blinded manner. Relationships between blood-biochemical and demographic parameters and the presence of GEVs were statistically analyzed.

RESULTS

Dynamic CT revealed gastric varices (n = 3, 11.1%), esophageal varices (n = 1, 3.7%), and gastrorenal shunts (n = 5, 18.5%). All patients with gastric varices had gastrorenal shunts. All gastric varices were endoscopically confirmed as being isolated and enlarged, with indications for preventive interventional therapy. A platelet count lower than 119 × 109 /L was identified as a predictor of GEV (area under the receiver operating curve, 0.946; sensitivity, 100%; and specificity, 87%).

CONCLUSIONS

GEVs are important complications that should not be ignored in patients who have undergone a Fontan procedure. Platelet counts lower than 119 × 109 /L may help to prompt patient screening by using abdominal dynamic CT to identify GEVs and their draining collateral veins in these patients.

Effect of Ventricular Pacing on Morbidity in Adults After Fontan Repair

Implantation of a permanent pacemaker is a negative prognostic marker in patients with Fontan palliation; however, data delineating outcomes in adult patients with pacemaker requirements are lacking. We hypothesize that high ventricular pacing burden is associated with adverse outcomes in adult Fontan patients. We performed a retrospective review comprising adult patients with history of Fontan repair. A high burden of ventricular pacing was defined as ≥40% pacing. Major adverse clinical events (MACE) were defined as all-cause mortality or need for advanced cardiac therapies (ventricular assist device or heart transplant). A total of 145 adult patients with Fontan were studied for a median of 3.1 years. Twenty (14%) patients had implanted pacemakers with ≥40% ventricular pacing. Twelve events occurred in those with ≥40% ventricular pacing (incidence 60.0%) versus 11 in those without (incidence 8.8%). In multivariable analysis, ≥40% ventricular-pacing (odds ratio 12.51, confidence interval [CI] 3.56 to 43.83, p <0.001) was associated with MACE independent of initial Fontan type, New York Heart Association functional class at baseline, or history of atrial tachyarrythmia. In survival analysis, patients with ≥40% ventricular pacing had nearly 8 times the risk of MACE compared with those with a lower ventricular pacing burden (hazard ratio 7.79, 95% CI 2.56 to 23.66, p <0.001), whereas patients with atrial-only or <40% ventricular pacing burden had a trend toward higher hazard of MACE compared with those without permanent pacemaker (hazard ratio 3.38, 95% CI 0.92 to 12.47, p = 0.07) that did not meet statistical significance. These findings suggest that high ventricular pacing burden contributes to poor outcomes in the adult Fontan patients and bear consideration when determining optimal treatment of tachyarrhythmias in this population.

Magnetic resonance elastography of the liver in patients status-post fontan procedure: feasibility and preliminary results

OBJECTIVE

The purpose of this study was to evaluate the feasibility of performing magnetic resonance elastography (MRE) as a screening tool for elevated liver stiffness in patients' status-post Fontan procedure.

BACKGROUND

With greater numbers of Fontan patients surviving far into adulthood, a factor increasingly affecting long-term prognosis is the presence of hepatic congestion and fibrosis. If detected early, steps can be taken to potentially slow or halt the progression of fibrosis. MRE is a relatively new, noninvasive imaging technique, which can quantitatively measure liver stiffness and provide an estimate of the extent of fibrosis.

METHODS

A retrospective study was conducted using MRE to evaluate liver stiffness in patients with a history of Fontan procedure. An MRE was performed in the same session as a clinical cardiac MRI. The liver was interrogated at four slice locations, and a mean liver stiffness value was calculated for each patient using postprocessing software. The medical records were reviewed for demographic and clinical characteristics.

RESULTS

During the time frame of this investigation, 17 MRE exams were performed on 16 patients. All patients had elevated liver stiffness values as defined by MRE standards. The median of the individual mean liver stiffness values was 5.1 kPa (range: 3.4-8.2 kPa). This range of liver stiffness elevation would suggest the presence of mild to severe fibrosis in a patient with standard cardiovascular anatomy. We found a significant trend toward higher liver stiffness values with greater duration of Fontan circulation (rs = 0.55, P = .02).

CONCLUSION

Our preliminary findings suggest that MRE is a feasible method for evaluating the liver in Fontan patients who are undergoing surveillance cardiac MRI. Further investigation with histologic correlation is needed to determine the contributions of hepatic congestion and fibrosis to the liver stiffness in this population.

Double inlet left ventricle

Double inlet left ventricle is a common form of univentricular atrioventricular connection. The clinical presentation is varied depending on associated lesions and the arrangement of great arteries. Management generally involves staging toward the ultimate goal of Fontan palliation. With advances in noninvasive diagnosis, surgical and postoperative care outcomes have significantly improved in the past decade. Most patients with double inlet left ventricle can go to school, play recreationally, and are gainfully employed. Some patients continue to pose difficult and frustrating medical problems, including arrhythmias, ventricular failure, atrioventricular valve insufficiency, subaortic obstruction, protein-losing enteropathy, and plastic bronchitis.

Long-term results of the Fontan operation for double-inlet left ventricle

The purpose of this study was to quantify and determine predictors of long-term survival and functional outcome in patients with double-inlet left ventricle (DILV) after the Fontan operation. The Fontan operation has become the procedure of choice for DILV. Early survival has improved, but mortality and morbidity persist. Record review and follow-up questionnaires were used to ascertain the status of 225 patients with DILV who had Fontan operations from 1974 to 2001 at the Mayo Clinic. The median age at operation was 9 years. The median follow-up period was 12 years (range 3 months to 25 years). There were 22 deaths (9.3%) <30 days after the operation. Early mortality decreased to 3% (2 of 70 patients) after 1989. Overall late survival was 78% (159 of 203 patients). Actuarial survival for the 203 early operative survivors at 5, 10, 15, and 20 years was 91%, 80%, 73%, and 69%, respectively. Forty-nine percent (99 of 203) had additional surgical procedures after the Fontan operation. Other frequent late events were atrial flutter or fibrillation (57%), protein-losing enteropathy (9%), and thromboembolic events (6%). Current health status was described as good or excellent by 84% of patients, fair by 18%, and poor by 12%. In conclusion, the Fontan operation for DILV is now performed with a low operative mortality rate. Long-term survival has improved, and most patients have good functional status.

Anatomoechocardiographic correlation double inlet left ventricle

Double inlet left ventricle (LV) is a type of atrioventricular connection in which the morphologically LV receives more than 50% of the atrioventricular valves when they are separate, or more than 75% of a common atrioventricular valve. The aim of this study was to establish an anatomoechocardiographic correlation between the morphologic features of equivalent anatomic specimens and the echocardiographic images of patients to provide a means of interpreting the image correctly and a more precise diagnosis of the cardiac defect. Echocardiography was used to study 18 patients with LV double inlet who were seen in a congenital heart disease clinic. The morphology of 17 hearts with this malformation from the department of embryology was analyzed to compare the anatomic features with their echocardiographic images. Echocardiography proved to be a noninvasive diagnostic tool that allowed characterization of anatomic and functional aspects of double inlet LV.

Cardiac transplantation after the Fontan or Glenn procedure

OBJECTIVES

The purpose of this study was to review the clinical course and outcome of cardiac transplantation after a failed Glenn or Fontan procedure.

BACKGROUND

Late complications of the Glenn or Fontan procedure, including ventricular failure, cyanosis, protein-losing enteropathy, thromboembolism, and dysrhythmias often lead to significant morbidity and mortality. If other therapies are ineffective, cardiac transplantation is the only therapeutic recourse. Transplantation in this unique population presents significant challenges in the operative and perioperative periods.

METHODS

The anatomic diagnoses, previous operations, clinical status, and indications for transplantation were characterized in patients transplanted after a Glenn or Fontan procedure. Outcomes after transplantation, including postoperative complications and mortality, were reviewed. Comparisons were made between survivors and nonsurvivors.

RESULTS

Primary orthotopic cardiac transplantation was performed in 35 patients (mean age 15.7 +/- 8.5 years) with a mean follow-up of 54 +/- 46 months. A total of 11 patients had undergone a Glenn shunt and 24 patients a Fontan procedure. Indications for transplantation were a combination of causes including ventricular dysfunction, failed Fontan physiology, and/or cyanosis. Ten patients died <or=2 months after transplantation; nine of the deaths occurred in the Fontan patients. Overall, one-year survival was 71.5%, and five-year survival was 67.5%. Survival was not significantly different between patients transplanted after a Glenn or Fontan procedure and patients transplanted for other etiologies.

CONCLUSIONS

Cardiac transplantation can be performed successfully in patients with end-stage congenital heart disease after a Glenn or Fontan procedure, with outcomes similar to transplantation for end-stage heart failure secondary to other etiologies.

Impaired systemic ventricular relaxation affects postoperative short-term outcome in Fontan patients

OBJECTIVES

Systemic ventricular end-diastolic pressure has been used as a predictor of outcome in patients undergoing the Fontan operation. However, this index only evaluates late diastolic function and does not assess active ventricular relaxation during the phase of early diastole, a key component of systemic venous pathway flow. This study sought to examine whether impaired preoperative systemic ventricular relaxation, expressed as the time constant of isovolumic relaxation (tau), affects short-term postoperative outcome in Fontan patients.

METHODS

All patients who underwent Fontan operation between May 1998 and November 2001 were enrolled. Tau was calculated from digitized preoperative systemic ventricular pressure tracings. Standard preoperative invasive indices were also recorded and analyzed. These independent variables were then entered into a multiple stepwise regression model, with length of intensive care unit stay, length of hospital stay, and prolonged pleural effusion as outcome variables.

RESULTS

Twenty-seven patients fulfilled inclusion criteria. Systemic left ventricle predominated, and all patients had undergone prior staged palliation. Extracardiac Fontan was the commonest operative technique. Of the independent variables examined, tau was the only statistically significant predictor of length of intensive care unit stay (P <.001) and length of hospital stay (P =.002). None of the independent variables predicted pleural effusion greater than 10 days.

CONCLUSIONS

Tau was the only significant preoperative invasive predictor of short-term outcome in the Fontan patients. This illustrates the importance of systemic ventricular relaxation and highlights the need for a more comprehensive assessment of diastolic function before the Fontan operation.

Hepatic dysfunction following the Fontan procedure

OBJECTIVES

The Fontan procedure offers a palliation for the hemodynamic derangements associated with congenital heart lesions characterized by a single functional ventricle, but it causes a chronically elevated systemic venous pressure that may result in hepatic congestion. The objective of this study was to characterize hepatic function and its relationship to cardiac function in children who had undergone the Fontan procedure.

METHODS

In a cross-sectional study of 11 children aged 38 months to 216 months (mean, 149 months), the authors evaluated indices of cardiac and hepatic function, including galactose clearance, Doppler hepatic ultrasonography, synthetic function, and markers of liver injury, at 9 months to 176 months (mean, 100 months) after children had undergone the Fontan procedure.

RESULTS

The most common biochemical abnormality of hepatic function was a prolongation of the prothrombin time and a low factor V level. There was a trend toward progressive abnormality in prothrombin time with increasing interval since the Fontan procedure. Galactose elimination half-life and galactose elimination capacity were inversely correlated with the time after Fontan (R2= 0.65, P = 0.004). There was no relationship between cardiac functional measurements and liver function.

CONCLUSIONS

Prothrombin time and galactose elimination half-life are abnormal in children who have undergone the Fontan procedure and may be useful markers of hepatic function in the longitudinal assessment of these patients.

Trans-aortic His bundle ablation with permanent ventricular pacing via the coronary sinus in L-transposition of great arteries with classic Fontan procedure

We report findings in a patient with 1-transposition of great arteries with single ventricle and classic Fontan procedure who required both His bundle ablation for palliation of refractory atrial tachycardia and placement of a transvenous dual-chamber atrio-ventricular permanent pacemaker for hemodynamic support. A method for retrograde trans-aortic His bundle ablation in this congenital anomaly and subsequent placement of permanent dual chamber pacemaker using the right atrium and coronary sinus as an access to the ventricle is described.

[Single-stage Fontan procedure: early and late outcome in 124 patients]

INTRODUCTION AND OBJECTIVES

The Fontan procedure was designed to palliate complex congenital heart disease with univentricular physiology. A retrospective study was made to document the determinants of early (</= 30 days) and late (>/= 31 days) mortality with the modified Fontan procedure performed in one-stage over a 22-year period.

MATERIAL AND METHODS

Between 1978 and 2000, 102 atriopulmonary, 16 cavopulmonary, and 6 Kawashima type anastomoses were performed to palliate complex congenital heart defects in 124 patients with a mean age of 7.3 4.7 years. Forty-five patient and procedure-related variables were analyzed in relation to mortality. All events were verified.

RESULTS

There were 29 early (23%) and 20 late (16%) deaths. Estimated survival at 30 days, 2 years, 5 years, and 20 years was 78, 75, 66, and 50%, respectively. Subaortic stenosis, protein-losing enteropathy, and arrythmia were observed in 8, 5 and 33 patients, respectively, after surgery. Univariate and multivariable analysis indicated that left ventricular end-diastolic pressure (>/= 13 mmHg), mean pulmonary pressure (>/= 19 mmHg), mitral stenosis/atresia, atrioventricular valve regurgitation, visceral heterotaxia, absence of fenestration, risk factors criteria, duration of extracorporeal circulation, and operative technique were associated with early mortality. Reoperation, arrhythmia, and pacemaker implantation were predictors of late death. Forty percent remained free from surgical or catheter reintervention after Fontan operation at 20 years.

CONCLUSIONS

The outcome of Fontan procedure is profoundly affected by patient-related variables (ventricular function and pulmonary circulation). Postoperative arrhythmia and reoperation shortened the lifespan of the Fontan circulation model in patients with atriopulmonary connections. Total cavopulmonary anastomosis improves the physiology of univentricular circulation. In the light of our findings, the modified Fontan procedure (one or two stages) should be performed early in life to better preserve ventricular and pulmonary vascular function.

The Fontan procedure in adults

SETTING

Tertiary adult congenital cardiac referral centre.

DESIGN

Retrospective cross sectional analysis.

OBJECTIVES

To report our 20 year experience with adult Fontan operations, and to compare late outcome in patients with single ventricle with definitive aortopulmonary or cavopulmonary shunt palliation.

PATIENTS AND MAIN OUTCOME MEASURES

Patients older than 18 years undergoing Fontan operation between 1 January 1982 and 31 December 1998 were identified. Mortality and late outcome were derived from hospital records. These patients were compared with a cohort of 50 adults with single ventricle who had not undergone a Fontan operation.

RESULTS

61 adults, median age 36 years (range 18-47 years), with a median follow up of 10 years (range 0-21 years) were identified. Actuarial survival was 80% at one year, 76% at five years, 72% at 10 years, and 67% at 15 years. Compared with before the Fontan operation, more patients were in New York Heart Association (NYHA) functional class I or II at the latest follow up (80% v 58%, p < 0.001). Systolic ventricular function deteriorated during follow up such that 34% had moderate to severe ventricular dysfunction at the latest follow up compared with 5% before Fontan (p < 0.001). Arrhythmia increased with time (10% before Fontan v 57% after 10 years, p < 0.001). Fontan patients had improved NYHA functional class, ventricular function, atrioventricular regurgitation, and fewer arrhythmias than the non-Fontan group at the latest follow up.

CONCLUSION

The Fontan operation in adults has acceptable early and late mortality. Functional class, systolic ventricular function, atrioventricular regurgitation, and arrhythmia deteriorate late after surgery but to a lesser degree than in non-Fontan patients with a single ventricle.

Late outcome after the Fontan procedure

Relatively little data exist on intermediate to late functional status and survival of patients after Fontan procedures. The first 500 patients undergoing a Fontan procedure at Children's Hospital (Boston, MA) were reviewed and then followed. There were 31 late failures among 410 patients contacted, and probability of survival at 10 years was 71.4%. Most patients were in functional class I or II, and only rare patients developed protein-losing enteropathy. Atrial flutter had developed in 16% of patients. Continued follow-up of Fontan patients will be necessary indefinitely. Copyright 1998 by W.B. Saunders Company

The Fontan procedure for tricuspid atresia: early and late results of a 25-year experience with 216 patients

OBJECTIVES

We assessed the operative and late mortality and the present clinical status of 216 patients with tricuspid atresia who had a nonfenestrated Fontan procedure performed at the Mayo Clinic in the 25-year period 1973 to 1998.

BACKGROUND

The Fontan operation eliminates the systemic hypoxemia and ventricular volume overload characteristic of prior forms of palliation. However, it originally did so at the cost of systemic venous and right atrial hypertension, and the long-term effects of this "price" were unknown when the procedure was initially proposed.

METHODS

We reviewed the clinical records of the 216 patients retrospectively. These were arbitrarily grouped into early (1973 through 1980), middle (1981 through 1987) and late (1988 through 1997) surgical eras. Patient outcome was also analyzed according to age at surgery. Operative and late mortality rates were determined and present clinical status was ascertained in 167 of 171 surviving patients.

RESULTS

Overall survival was 79%. Operative mortality steadily declined and was 2% (one of 58 patients) during the most recent decade. Late survival also continues to improve. Age at operation had no effect on operative mortality, and late mortality was significantly increased only in patients who were operated on at age 18 years or older. Eighty-nine percent of surviving patients are currently in New York Heart Association class I or II.

CONCLUSIONS

The initial 25-year experience with the nonfenestrated Fontan procedure for tricuspid atresia has been gratifying, with most survivors now leading lives of good quality into adulthood. These results justify continued application of this procedure for children born with tricuspid atresia.

Unexpected death after reconstructive surgery for hypoplastic left heart syndrome

BACKGROUND

Although operative mortality for reconstructive surgery for hypoplastic left heart syndrome continues to improve, nonoperative mortality, especially in the first year of life, remains relatively high. A number of patients who are thought to be clinically well at hospital discharge die unexpectedly. The goal of the present study was to determine the incidence of and risk factors for unexpected death in patients with hypoplastic left heart syndrome.

METHODS

Retrospectively, we determined the incidence of unexpected death among 536 patients with hypoplastic left heart syndrome who were discharged to home after stage I surgical procedure. To identify potential risk factors, a nested case-control analysis was undertaken.

RESULTS

Unexpected death occurred in 22 of 536 patients (4.1%) discharged to home after stage I surgical procedure. The median age at unexpected death was 79 days (range, 25 to 227 days). Seizures preceded cardiac arrest in 2 patients, and ventricular arrhythmias were documented in 3 additional patients during attempted resuscitation. Autopsy studies were performed in 12 patients and identified residual lesions that may have contributed to death in 2 patients. In multivariate analysis documented perioperative arrhythmia and earlier year of stage I surgical procedure were associated with an increased risk for unexpected death (p = 0.03 and p = 0.04, respectively). There were 4 additional patients who had unexpected death after subsequent cavopulmonary operation at a median age of 1.6 years (range, 0.9 to 3.8 years).

CONCLUSIONS

Unexpected death occurred in more than 4% of patients with hypoplastic left heart syndrome who were discharged to home after stage I surgical procedure and was most common in the first several months of life. Factors that may contribute to unexpected death include residual lesions, arrhythmias, and neurologic events, although in the majority of cases the cause remains largely unknown.

[Clinical guidelines of the Spanish Society of Cardiology for the most frequent congenital cardiopathies]

The use of diagnostic and therapeutic techniques is very important to ensure optimum, effective treatment in patients with heart disease to thereby obtain an adequate cost-benefit relationship. The aim of establishing guidelines for the evaluation and management is to achieve this relationship, but these guidelines are difficult to establish in pediatric cardiology despite 50 years of experience in this field. At present a large group of patients may benefit from these guidelines due to the improvement in the diagnostic techniques and better treatment results in congenital heart disease in the newborn. Protocols have been established in some groups and in others in which this is not possible, descriptive analysis and therapeutic schedules have been determined.

Improved early results with cavopulmonary connections

BACKGROUND

We describe the recent results in a large cohort of patients with functionally single ventricle who underwent various modifications of cavopulmonary connections.

METHODS

Using the database at our institution, we identified all children who underwent cavopulmonary connection operations between June 1995 and June 1997. Demographic data, surgical history, and perioperative course were reviewed.

RESULTS

We performed 130 consecutive operations in 113 patients. The procedures included superior cavopulmonary connections in the form of the HemiFontan procedure in 45 instances, and bidirectional Glenn procedures in 11, and bilateral superior cavopulmonary connections in 7. The median age of these patients was 7.0 months. We completed Fontan operations using a fenestrated lateral tunnel on 47 occasions, and using an extracardiac conduit 9 times, 5 of which were fenestrated. A lateral tunnel without fenestration was constructed in one patient. The median age for these procedures was 19.5 months. In the remaining 10 instances, we revised Fontan procedures at a median age of 8 years. Diagnoses included hypoplastic left heart syndrome in 43 patients, double outlet right ventricle in 22, heterotaxy in 13, tricuspid atresia in 13, and a miscellaneous group accounting for the other 22. One death (0.7%) occurred within 30 days of surgery. Clinical seizures occurred in 7 children (5.3%), 6 had no residual neurologic deficits. Atrial pacing was needed in 14 children (10.7%) because of transient junctional rhythm, and 2 received treatment for supraventricular tachycardia. Pleural effusions were diagnosed radiographically after 31 of 130 (24%) procedures. Diuretic therapy resolved the effusion in 21 of these, with only 6 children requiring thoracostomy catheter drainage, and 4 undergoing thoracentesis alone. The median length of stay on the intensive care unit was 2 days, with a range from 1 to 30 days, and median stay in hospital was 6 days, with a range from 3 to 58 days.

CONCLUSION

Mortality and perioperative morbidity after cavopulmonary connections have decreased dramatically in the current era. The long-term results of staged reconstruction for functionally single ventricle, nonetheless, await ongoing study.

Influence of ventricular morphology on outcome after the Fontan procedure

The modified Fontan procedure has gained wide acceptance in the treatment of various congenital heart defects. Determination of risk factors for mortality remains an important issue for optimizing patient selection for the Fontan procedure. Conflicting results have been reported about whether ventricular morphology is a risk factor in these patients. Survival free of Fontan takedown or cardiac transplantation was assessed in the first 500 patients undergoing the Fontan procedure at our institution. This survival was correlated with ventricular morphology as evaluated by angiography. Both multivariate and univariate analyses indicated ventricular morphology was predictive of early survival free of Fontan takedown or cardiac transplantation following the procedure. However, there was no statistical evidence for ventricular morphology being a risk factor for mortality in patients alive 6 months after the procedure. Ventricular morphology is a risk factor for early survival in patients undergoing a Fontan procedure, with left ventricular morphology associated with a better early survival than right ventricular morphology.

Electrophysiological mapping and ablation of intra-atrial reentry tachycardia after Fontan surgery with the use of a noncontact mapping system

BACKGROUND

Atrial tachyarrhythmias are a complication of Fontan surgery. Conventional electrophysiological mapping and ablation techniques are limited by the complex anatomic and surgical substrate and a high arrhythmia recurrence rate. This study investigates the use of noncontact mapping to identify arrhythmia circuits and guide ablation in Fontan patients.

METHODS AND RESULTS

Eleven arrhythmias were recorded in 6 patients. Noncontact mapping improved recognition of the anatomic and surgical substrate and identified exit sites from zones of slow conduction in all clinical arrhythmias. Radiofrequency linear lesions were targeted across these critical zones in 5 patients. One patient underwent surgical cryotherapy. Although immediate success was achieved in 3 of 5 patients with radiofrequency ablation, 2 patients had a recurrence after a mean of 6.4 months of follow-up. The patient who underwent cryoablation remains free of arrhythmias.

CONCLUSIONS

Noncontact mapping can identify arrhythmia circuits in the Fontan atrium and guide placement of ablation lesions. Arrhythmia recurrence is high, possibly because of inadequate lesion creation rather than inaccurate mapping and lesion targeting.

Evolution of the Fontan procedure in a single center

BACKGROUND

Surgical approaches to single ventricle variants include staged, fenestrated, and completed Fontan operations. This study compares outcomes with these modifications of the Fontan operation at a single center.

METHODS

Preoperative risk factors and operative results were analyzed by multivariate techniques in 129 patients undergoing modified Fontan operations since March 1988.

RESULTS

Overall early and late mortality was 5.4% and 0.8%, respectively. Before 1993, completed Fontan operation using right atrial to pulmonary artery anastomosis without fenestration was performed in the majority of patients (44 of 58; 76%). During this period, 10 of 17 patients at high risk had completed Fontan with three takedowns. In 1994, the staged hemi-Fontan and modified Fontan with a lateral tunnel anastomosis and with or without small fenestration (2.5 to 4 mm) were introduced. The majority of patients at high risk during this period underwent hemi-Fontan followed by fenestrated Fontan with no takedowns. Late atrial dysrhythmias occurred in 6 patients (4.7%), generally with larger fenestrations or right atrial to pulmonary anastomoses. Three patients (2.3%) had a stroke, 2 with large (> or = 4 mm) fenestrations. Of 38 fenestrations, 32 (84%) closed spontaneously by 1 year. No protein-losing enteropathy occurred. Most patients (118 of 121) were in New York Heart Association class I/II 4.5 years postoperatively. By multivariate analysis, only Down's syndrome (p < 0.001) predicted early mortality, whereas both Down's syndrome and a systemic right ventricle decreased late survival (p < 0.006).

CONCLUSIONS

Proper selection of patients for modifications of the Fontan procedure resulted in excellent early and late survival with a low incidence of atrial dysrhythmia and stroke. Midterm functional outcomes were excellent.

Predictors of early- and late-onset supraventricular tachyarrhythmias after Fontan operation

BACKGROUND

The objectives of our study were to determine the frequency of supraventricular tachyarrhythmias (SVTAs) among modifications of the Fontan operation and identify risk factors for developing SVTA.

METHODS AND RESULTS

The population consisted of all patients who had any modification of the Fontan operation at the Mayo Clinic between 1985 and 1993. Clinically significant SVTAs were those requiring initiation or change of antiarrhythmic treatment, and they were divided into early SVTAs (<30 days after the operation) and late SVTAs (>/=30 days after the operation). Clinical histories were reviewed, and health status questionnaires were sent. Four hundred ninety-nine patients had various modifications of the Fontan operation. Frequency of early SVTA was 15%. Risk factors identified by multivariate analysis for early SVTA were AV valve regurgitation, abnormal AV valve, and preoperative SVTA. Frequency of late SVTA was 6% by 1 year, 12% by 3 years, and 17% by 5 years. Risk factors for late SVTA were age at operation (<3 or >/=10 years) and systemic AV valve replacement. By univariate and multivariate analysis, the type of Fontan operation was not a significant risk factor for late SVTA when all 6 modifications were considered. However, when we analyzed the frequency of late SVTA for the 2 recently used modifications, we found a lower frequency of late SVTA in patients with atriopulmonary connection with lateral tunnel compared with those with total cavopulmonary connection.

CONCLUSIONS

Postoperative SVTA continues to be a significant problem. Risk factors for SVTA are AV valve regurgitation, abnormal AV valve, preoperative SVTA, and age at operation. Frequency of SVTA does not appear to be related to type of Fontan procedure except for slightly lower frequency in patients with atriopulmonary connection with lateral tunnel compared with those with total cavopulmonary connection.

Biventricular hearts not amenable to biventricular repair

Many hearts, although considered morphologically biventricular, may not be candidates for a biventricular repair. Such patients are best placed on a Fontan algorithm. This article reviews in broad principles those hearts that, despite being biventricular, do not lend themselves to a two-ventricle repair.

[Cardiac transplant in single ventricle]

Univentricular heart is an uncommon congenital heart disease. A select group of these patients (those with severe pulmonary stenosis or atresia) can reach adult age with different degrees of heart failure and severe chronic hypoxemia. Patients with adequate pulmonary tree development are likely to undergo heart transplantation when usual palliative techniques are contraindicated. Three cases of univentricular heart with pulmonary stenosis in which heart transplantation was the optimal choice are reported. Different techniques used to assess pulmonary tree development are analysed.

Fontan operation in five hundred consecutive patients: factors influencing early and late outcome

OBJECTIVES

The purpose of this study was to review a large, evolving, single-center experience with the Fontan operation and to determine risk factors influencing early and late outcome.

METHODS

The first 500 patients undergoing modifications of the Fontan operation at our institution were identified. Perioperative variables were recorded and a cross-sectional review of survivors was undertaken.

RESULTS

The incidence of early failure decreased from 27.1% in the first quartile of the experience to 7.5% in the last quartile. In a multivariate model, the following variables were associated with an increased probability of early failure: a mean preoperative pulmonary artery pressure of 19 mm Hg or more (p < 0.001), younger age at operation (p = 0.001), heterotaxy syndrome (p = 0.03), a right-sided tricuspid valve as the only systemic atrioventricular valve (p = 0.001), pulmonary artery distortion (p = 0.04), an atriopulmonary connection originating at the right atrial body or appendage (p = 0.001), the absence of a baffle fenestration (p = 0.002), and longer cardiopulmonary bypass time (p = 0.001). An increased probability of late failure was associated with the presence of a pacemaker before the Fontan operation (p < 0.001). A morphologically left ventricle with normally related great arteries or a single right ventricle (excluding heterotaxy syndrome and hypoplastic left heart syndrome) were associated with a decreased probability of late failure (p = 0.003).

CONCLUSIONS

These analyses indicate that early failure has declined over the study period and that this decline is related in part to procedural modifications. A continuing late hazard phase is associated with few patient-related variables and does not appear related to procedural variables.

Functional outcome after the Fontan operation: factors influencing late morbidity

OBJECTIVES

The purpose of this study was to describe the functional outcome of a large number of patients after modifications of the Fontan operation and to investigate perioperative risk factors that might influence late functional state.

METHODS

A comprehensive cross-sectional review of the first 500 patients undergoing a Fontan operation at our institution was undertaken. Those surviving with an intact Fontan circulation were reviewed by questionnaire to assess functional status and medication history. Medical records, chest roentgenograms, echocardiograms, cardiac catheterizations, and laboratory investigations were also reviewed to assess postoperative status.

RESULTS

Three hundred sixty-three long-term survivors with an intact Fontan circulation were identified during cross-sectional follow-up. Median age at operation was 5.0 years (range 0.4 to 31 years), and median follow-up was 5.4 years (range 1.7 to 20 years). Most patients (91.1%) were in New York Heart Association class I or II. In a multivariate model, poor (class III or IV) functional state was associated with longer duration of follow-up (p < 0.001), a prior atrial septectomy (p = 0.03), and a prior main pulmonary artery-ascending aorta anastomosis (p = 0.05).

CONCLUSIONS

A poor functional outcome is uncommon after the Fontan operation but becomes more frequent with increasing duration of follow-up.

The Fontan procedure for pulmonary atresia with intact ventricular septum: operative and late results

OBJECTIVES

The goals of the study were to evaluate the operative and late mortality associated with the Fontan procedure in patients with pulmonary atresia and an intact ventricular septum and to obtain follow-up information on the current clinical status of surviving patients.

BACKGROUND

Between 1979 and October 1, 1995, 40 patients with the anomaly had a nonfenestrated Fontan procedure performed at the Mayo Clinic. Because there are no previously published reports involving a series of this size in which the Fontan approach was used for this condition, a review of patient outcomes was thought to be of value.

METHODS

The medical records of the 40 patients were reviewed retrospectively, and 34 were determined to be alive. The status of the survivors as of late 1995 was then ascertained by direct examination, questionnaire or telephone follow-up.

RESULTS

There were three operative deaths and three late deaths. The current ages of the 34 survivors ranged from 4 to 30 years (median 13). Thirty-three of the 34 survivors were thought to be in New York Heart Association functional class I or II, and all but three of these patients, of school age or older, were either full-time students or working full time. The three adults who were not employed thought they were capable of working but were not doing so because of socioeconomic reasons. More than half of the patients were not receiving cardiovascular medications.

CONCLUSIONS

These overall gratifying early and late results encourage continued application of this operation for appropriately selected patients with this complex congenital cardiovascular anomaly.

Cardiorespiratory response to exercise after modified Fontan operation: determinants of performance

OBJECTIVES

This study sought to measure the cardiorespiratory responses to exercise and to identify the perioperative determinants of exercise performance in children, adolescents and young adults who underwent the modified Fontan operation.

BACKGROUND

Several studies of the cardiorespiratory responses to exercise after the Fontan operation have demonstrated subnormal maximal oxygen uptake and exercise heart rate, but the perioperative variables that ultimately affect exercise responses have not been assessed systematically.

METHODS

The study included 59 of the 548 patients who underwent a modified Fontan operation between January 1, 1984 and December 31, 1993 at the Mayo Clinic. Spirometry was performed at rest in all patients before exercise testing. The patients then exercised using a previously calibrated cycle ergometer and a 3-min incremental cycle exercise protocol. Multiple linear regression analysis was used to determine a subset of variables associated with oxygen uptake at peak exercise (VO2max), blood oxygen saturation (O2sat) and heart rate at peak exercise (HRmax).

RESULTS

VO2max ranged from 29% to 95% of normal value; O2sat at peak exercise ranged from 77% to 96%; and HRmax ranged from 39.7% to 97.4% of normal value. Multivariate analysis showed that log VO2max/kg2/3 was associated with age at exercise, male gender, body surface area, preoperative confluent pulmonary arteries and rest VO2max/kg2/3. Preoperative left pulmonary artery stenosis, the presence of a classic Glenn anastomosis at exercise and rest O2sat were associated with O2sat at peak exercise. Age, body surface area at exercise, heart rate at rest and diastolic blood pressure were associated with HRmax at exercise.

CONCLUSIONS

Subnormal VO2max and HRmax values were demonstrated at peak exercise. Several perioperative variables were associated with VO2max and O2sat at peak exercise. The presence of a classic Glenn anastomosis was associated with decreased O2sat at peak exercise, suggesting intrapulmonary shunting with the classic Glenn anastomosis.

Factors that influence the development of atrial flutter after the Fontan operation

OBJECTIVES

Atrial flutter is a frequent, potentially fatal complication of the Fontan operation, but risk factors for its development are ill defined. We evaluated clinical features that might predict the development of atrial flutter in patients who had a Fontan operation.

METHODS

We evaluated 334 early survivors of a Fontan operation done between April 1973 and July 1991 (mean follow-up, 5.0 +/- 3.8 years). Evaluation included electrocardiography, Holter monitor recordings, and chart review. Modifications of the Fontan operation included an extracardiac conduit (n = 43), an atriopulmonary anastomosis (n = 117), or a total cavopulmonary anastomosis (n = 174). Patient, time, and procedure-related variables were analyzed with respect to the development of atrial flutter.

RESULTS

Atrial flutter was identified in 54 (16%) patients at a mean of 5.3 +/- 4.7 years (range 0 to 19.7 years) after Fontan operation. Atrial flutter developed sooner and was more likely to occur in patients who were older at the time of Fontan operation (12.4 +/- 7.6 vs 6.3 +/- 5.2 years; p < 0.001), had a longer follow-up interval (8.7 +/- 3.9 vs 4.4 +/- 3.4 years; p < 0.001), had a prior atrial septectomy or pulmonary artery reconstruction (p < 0.01), and had worse New York Heart Association class symptoms (p < 0.02). The presence of sinus node dysfunction was associated with a higher incidence of atrial flutter (p < 0.001). Although there was a lower prevalence of atrial flutter in those patients with a total cavopulmonary anastomosis, the follow-up for this group was shorter. Anatomic diagnoses, perioperative hemodynamics, and other previous palliative operations were not associated with an increased incidence of atrial flutter. Multivariate analysis identified age at operation, duration of follow-up, extensive atrial baffling, and type of repair as factors associated with the development of atrial flutter after Fontan operation.

CONCLUSION

Atrial flutter continues to develop with time after the Fontan operation. Further follow-up is necessary to determine whether a total cavopulmonary anastomosis reduces the incidence of atrial flutter.

Embolic stroke after ligation of the pulmonary artery in patients with functional single ventricle

In the setting of functional single ventricle with pulmonary overcirculation, pulmonary artery banding is frequently used to alleviate symptoms and to prepare for staged repair. At subsequent cavopulmonary anastomosis or Fontan procedure, the pulmonary artery may be ligated at the site of the pulmonary band. This article describes the association of embolic stroke and thrombus in a ligated or divided pulmonary artery stump in three patients with functional single ventricle. These events occurred from 1990 through 1992 among the 1700 inpatient pediatric cardiology admissions at two institutions. The patients, ranging in age from 15 months to 9 years, had cerebral infarctions documented by computed axial tomography scan or magnetic resonance imaging associated with the echocardiographic finding of thrombus in the proximal pulmonary artery stump after the embolic strokes. The strokes occurred 5 days to 5 years after surgery. Two patients had a second infarction within 2 to 5 weeks of the initial stroke. It is concluded that the presence of the ligated pulmonary artery stump may place patients at risk for embolic stroke. Surgical approaches to reduce the risk of thrombus formation should be considered prospectively in this patient group.

Pregnancy outcomes after the Fontan repair

OBJECTIVES

This study sought to determine risks and outcome of pregnancy and delivery after the modified Fontan operation.

BACKGROUND

Increasingly, female Fontan patients reaching child-bearing years are interested in having children. To date, the number of reported pregnancies is small, and pregnancy has therefore been discouraged.

METHODS

One hundred ten of 126 female patients from the Fontan registries of the Mayo Clinic and University of California Los Angeles Medical Center responded to a mailed questionnaire. An additional six patients with a reported pregnancy from other centers were identified and reviewed to assess pregnancy outcomes.

RESULTS

Among the participating centers, a total of 33 pregnancies after Fontan operation for various types of univentricular heart disease were reported. There were 15 (45%) live births from 14 mothers, with 13 spontaneous abortions and 5 elective terminations. In the 14 women with live births, the median number of years between operation and pregnancy was 4 (range 2 to 14). Reported prepregnancy problems in these gravidas included atrial flutter in one patient and ventricular dysfunction, aortic regurgitation and atrioventricular valve regurgitation in another. One patient developed supraventricular tachycardia during pregnancy and had conversion to sinus rhythm. No maternal cardiac complications were reported during labor, delivery or the immediate puerperium. There were six female and nine male infants (mean gestational age 36.5 weeks; median weight 2,344 g). One infant had an atrial septal defect. At follow-up, mothers and infants were alive and well.

CONCLUSIONS

Pregnancy after the Fontan operation appears to have been well tolerated in 13 to 14 gravidas. There does appear to be an increased risk of miscarriage. The tendency to routinely discourage pregnancy may need to be reconsidered.

Improved early morbidity and mortality after Fontan operation: the Mayo Clinic experience, 1987 to 1992

OBJECTIVES

This study sought to evaluate changes in early morbidity and mortality as well as predictors of outcome in our most recent 339 patients undergoing modified Fontan operations.

BACKGROUND

The Fontan operation is the preferred definitive palliation for patients with functional single ventricles. Previously reported early mortality rates after Fontan operation have been substantial.

METHODS

Records of 339 consecutive patients who had a Fontan operation at the Mayo Clinic between 1987 and 1992 (recent cohort) were reviewed. This cohort was compared with the previous 500 patients who had Fontan operations performed between 1973 and 1986 (early cohort).

RESULTS

Recently, overall early mortality after Fontan has decreased significantly compared with that for the early cohort (from 16% to 9%, p = 0.002). This decline occurred despite increased anatomic complexity of patients. Short-term posthospital survival has also improved significantly in recent patients. One-year survival improved to 88% from 79%, and 5-year survival to 81% from 73% (p = 0.006). Patients with common atrioventricular valves and those who took daily preoperative diuretic medication or had either postoperative renal failure or elevated postbypass right atrial pressure were at increased risk for early mortality. Young age was not found to be a risk factor for early mortality. Early mortality for patients with heterotaxia decreased dramatically: recent 30-day mortality was 15% compared with 41% in the early heterotaxy cohort.

CONCLUSIONS

Many factors may have contributed to decreased early mortality after Fontan. Improved patient selection, younger age at time of operation, refinements in surgical techniques and postoperative management may all have had important roles. Proposed technical modifications of the Fontan operation must be evaluated in light of these improved results.

Fontan palliation versus heart transplantation: a comparison of charges

Surgical approaches to single-ventricle physiologic abnormalities have included Fontan palliation or transplantation. No cost expenditures have been published. This study compared expenditures between the Fontan procedure and heart transplantation. Between 1988 and 1992, records of 82 patients who underwent the Fontan procedure and 26 who underwent transplant were retrospectively reviewed. Charges for Fontan or transplant procedures were accrued from the date of surgical admission until discharge or patient death and included hospital, physician, and diagnostic laboratory charges. Additionally, the frequency and cost of postoperative hospital readmissions, outpatient evaluations, and diagnostic procedures were recorded for each patient. Estimated expenditures for each evaluated parameter were based on 1992 to 1993 dollar charges. The total expenditure (surgery plus yearly follow-up) for transplantation exceeded that for the Fontan procedure ($96,475 vs $29,730; p < 0.001). Although both groups had similar follow-up periods and mortality rates, the number of hospital readmissions and postoperative diagnostic tests was higher among transplant recipients. Within 1 postoperative year at least four high-risk patients who had undergone a Fontan procedure required listing for transplantation; the total costs of their combined procedures (approximately $80,000 + $3,000 to $5,000 annual outpatient charges) was markedly greater than the cost of the Fontan procedure alone. Although the expenditure for heart transplantation far exceeds that for the Fontan procedure, Fontan palliation in high-risk patients is ultimately more costly and increases postoperative morbidity. In this subgroup, we recommend heart transplantation as the initial definitive procedure because it may increase long-term survival rates and minimize health care expenditures.

Long-term outcome in patients with pacemakers following the Fontan operation

Patients with pacemakers after Fontan surgery compared favorably with nonpaced patients with respect to survival. In patients with atrioventricular block, dual chamber pacing was superior to VVI pacing.

A congenitally "poor" pulmonary artery is a major reason for exclusion from Fontan operation

We reviewed the clinical records of 185 patients who were possible candidates for Fontan operation. We did this to clarify whether all patients with suitable anomalies ultimately underwent a Fontan operation. Of the 152 patients with decreased pulmonary blood flow, 38 (26%) did not fulfill the criteria for Fontan operation, and 17 of the 33 patients (52%) with increased pulmonary blood flow (P < 0.01) were excluded as candidates. Of 48 non-candidate survivors, 19 had high pulmonary artery (PA) pressure or resistance and small PA (which we term "poor PA"), 17 had pulmonary hypertension, 6 had a markedly distorted PA, and 6 had severe ventricular dysfunction. A significant proportion of possible candidates with a suitable anomaly ultimately did not undergo a Fontan operation, because of "poor PA", a congenital condition that precluded Fontan operation.

Surgical reinterventions after modified Fontan operations

BACKGROUND

Surgical reinterventions after Fontan operations are still associated with high mortality. This investigation aims to summarize our experience with such repeated operations and to assess their efficacy.

METHODS

In 1983 through 1995 we performed 162 different modifications of Fontan operation. Repeated interventions were needed in 15 cases (9%). An analysis of all these cases is presented.

RESULTS

Repeated operation consisted of the closure of residual interatrial communication (3 patients), atrioseptostomy (4), subaortic stenosis resection (1), pulmonary balloon valvuloplasty (1), embolization of residual right ventricular-pulmonary arterial communication (1), pericardectomy (2), pleurectomy (1), pacemaker implantation (1), and takedown of the Fontan operation (1). The results of operation were judged as good in 6 cases (40%) and as satisfactory in 5 (33%); 4 patients (27%) died.

CONCLUSIONS

Repeated interventions aimed at the elimination of technical errors of the Fontan operation are successful in most cases. Atrial septostomy gives good results in the absence of anatomic causes of cardiac failure such as subaortic obstruction and atrioventricular valve insufficiency.

Comparison by computerized numeric modeling of energy losses in different Fontan connections

BACKGROUND

Different surgical techniques for creating a Fontan circulation can be used. The option of including an atrium in the circuit, or the technique used for connecting the caval veins to the pulmonary artery in a total cavopulmonary connection, frequently is empirical and is based on personal experience and preference. The hemodynamic and energetic differences between the different circuits are small, and short-term results are comparable. However, small, energetic differences may have significant implications for the long-term follow-up. The finite element method allows a computer-based modeling of the flow dynamics and pressure losses. It permits comparison of different Fontan connections in a single patient with identical geometry and functional conditions.

METHODS AND RESULTS

We compared the atriopulmonary connection with different types of cavopulmonary connections, which differed in the degree of symmetry of implantation of both caval veins into the right pulmonary artery. Based on anatomic models and physiological flow dynamics, three-dimensional geometries and finite element meshes were created with PATRAN; flows were calculated with POLYFLOW (B), and results were visualized with DATA VISUALIZER.

CONCLUSIONS

The atriopulmonary connection produces higher energy losses than the cavopulmonary connection (+/- 1 mm Hg at rest). The cavopulmonary connection is more efficient when the connection of the caval veins to the pulmonary artery is asymmetrical.

Cardiopulmonary function in adult patients late after Fontan repair

OBJECTIVES

The clinical status and exercise assessment of adult patients late after the Fontan operation were reviewed to determine cardiovascular function.

BACKGROUND

The Fontan operation is the final operation for many patients with tricuspid atresia or a single ventricle. Follow-up reports describe most patients to be in Canadian Cardiovascular Society functional class I or II. Objective measures of cardiac performance in the pediatric age group have shown significant dysfunction.

METHODS

Forty-seven adult patients were seen late after the Fontan operation at the Toronto Congenital Cardiac Centre for Adults. Thirty of these underwent cycle ergometry to determine maximal exercise capacity. Maximal ventilation, maximal oxygen uptake and anaerobic threshold were determined from a ramp exercise protocol. Ejection fraction at rest and during exercise was measured with gated radionuclide angiography. Results were compared with those of eight normal volunteers. Results are given as mean +/- SD.

RESULTS

Thirty patients underwent cardiopulmonary exercise testing 6.7 +/- 3.9 years after a first Fontan operation. Clinically 93% were in functional class I or II. The Fontan group patients had a significantly lower maximal work load (548 +/- 171 vs. 1,094 +/- 190 kilopond-meters, p < 0.00001), anaerobic threshold (11.2 +/- 2.9 vs. 23.6 +/- 4.6 ml/kg per min) and maximal oxygen consumption (14.8 +/- 4.5 vs. 42.1 +/- 10.0 ml/kg per min). Systemic ventricular ejection fraction was lower at rest (38 +/- 12% vs. 58 +/- 7%) and during exercise (40 +/- 15% vs. 70 +/- 8%).

CONCLUSIONS

Despite a clinical impression of good function, by objective measures adult patients continue to have significant cardiovascular limitation late after the Fontan operation.

Application of a transpulmonary double indicator dilution method for postoperative assessment of cardiac index, pulmonary vascular resistance index, and extravascular lung water in children undergoing total cavo-pulmonary anastomosis: preliminary results in six patients

Total cavo-pulmonary anastomosis (TCPA) is used for the functional correction of an increasing spectrum of congenital heart diseases. The passive pulmonary perfusion after surgical exclusion of the right ventricle has significant implications for the postoperative hemodynamic management of these patients. Because conventional pulmonary artery thermodilution catheters present methodologic problems in patients after TCPA, important cardiovascular variables such as cardiac index (CI) and pulmonary and systemic vascular resistance indices (PVRI, SVRI) usually cannot be assessed directly. In a preliminary series of six patients undergoing TCPA (age 6-22 years), the applicability of a transpulmonary double indicator dilution technique for postoperative determinations of CI, PVRI, SVRI, and extravascular lung water (EVLW) was investigated. After central venous injection of ice-cold indocyanine green (5 mg), thermal and dye dilution curves were recorded in the abdominal aorta using a combined 4F fiberoptic thermistor catheter. Qualitative assessment of the tracer curves did not show major differences in measurements in patients with pulsatile perfusion of the lungs. CI, SVRI, and EVLW could be determined by use of standard algorithms. Pulmonary perfusion pressure for the calculation of PVRI was based on the gradient between central venous and left atrial pressure. The quality of indicator dilution curves allowed determination of flow-related variables in 33 of a total of 34 sets of measurements. No catheter-related problems occurred during or after the period of investigation. Postoperative EVLW was within the range that is commonly accepted as normal for adults. Mean PVRI initially decreased during the postoperative course but showed a significant increase after extubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Systemic ventricular outflow obstruction progresses after the Fontan operation

To evaluate the course of systemic ventricular outflow obstruction after the Fontan operation, the records of 57 hospital survivors of that procedure were reviewed. Ventricular outflow obstruction was identified in 7 patients (group 1) and was absent in 50 patients (group 2). Overall, the ventricular outflow gradient in group 1 was 6.3 +/- 2.9 mm Hg (mean +/- standard error) before the Fontan operation and 7.6 +/- 3.9 mm Hg at hospital discharge. Ventricular outflow obstruction subsequently progressed to 80.1 +/- 17.3 mm Hg (range, 33 to 165 mm Hg; p < 0.02) a mean of 28 months postoperatively. One patient died of severe progressive ventricular outflow obstruction. Group 1 did not differ from group 2 in age, ventricular morphology, presence of a subaortic outflow chamber, prior shunt, or length of follow-up. Compared with group 2, however, patients in group 1 more commonly had an aorta arising from a hypoplastic ventricle (p < 0.001) and had undergone prior pulmonary artery banding (p = 0.005). We conclude that systemic ventricular outflow obstruction occurs commonly after a Fontan procedure (incidence, 12%; 70% confidence interval, 9% to 18%) and is a progressive lesion.

Noninvasive quantitative evaluation of the morphology of the major pulmonary artery branches in cyanotic congenital heart disease. Angiocardiographic and echocardiographic correlative study

BACKGROUND

Precise noninvasive evaluation of pulmonary artery (PA) morphology is extremely important for medical and surgical management of patients with cyanotic heart disease. In this study, the accuracy of two-dimensional echocardiography combined with color Doppler flow mapping to assess the size, stenosis, and atresia of the major PA branches was examined using a new parasternal approach.

METHODS AND RESULTS

With the use of right and left high parasternal windows, we visualized each of the major portions along the right (R-PA) and left (L-PA) pulmonary arteries in 45 of the 47 examinations (96%) in 38 patients with cyanotic heart disease. The patients were between 13 days and 20 years old (mean age, 2.9 years). The internal diameters of the major PA branches were measured at three points along the R-PA (the proximal, mid, and distal portions) and at the proximal and distal portions on the L-PA in systole by both two-dimensional echocardiography and angiography. In addition, the diameter of the stenosis in the PA branch was measured. These PA values as determined by two-dimensional echocardiography correlated well with those obtained by angiography (r = .95 to .97). By two-dimensional echocardiography with color Doppler flow mapping, 17 of 19 lesions with stenoses or atresia of the major PA branches were predicted as defined by angiography (sensitivity, 89.5%; specificity, 100%). Differences between the distal parts of the L-PA and R-PA of > 30% in diameter were determined by angiography in 15 examinations and by two-dimensional echocardiography in 12 examinations (sensitivity, 80%; specificity, 97.4%).

CONCLUSIONS

Our technique permits noninvasive evaluation of the size, stenoses, and atresia of the major portions of the PA branches in patients with cyanotic heart disease both before and after surgery.