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

Heterotaxy Syndrome With Right Isomerism and Interrupted Inferior Vena Cava: A Case Report and Literature Review

Heterotaxy syndrome (HS) occurs in developing embryos due to an inability to establish the normal anatomy, which manifests as abnormal symmetry and malposition of the thoracoabdominal viscera and vasculature, including cardiac and extracardiac anomalies. It is classified as right or left atrial isomerism. This classification depends on the atrial appendage morphology and the extracardiac defect associated with it. Right isomerism usually presents with right atrial appendages (RAA), asplenia, total anomalous pulmonary venous return, and severe pulmonary stenosis. In contrast, left isomerism usually presents with left atrial appendages, polysplenia, and an interrupted inferior vena cava (IVC). The interrupted IVC feature has never been reported with the right isomerism. Diagnosis of HS may take place prenatally or a few days postnatally due to the severe cardiac defect, whereas a left isomerism diagnosis may be delayed until adulthood. Despite the popularity of the HS classification, we reported a rare presentation of an interrupted IVC, dextrocardia, a right-sided aortic arch, and a total anomalous pulmonary venous return, which occurred along with the right isomerism major components (asplenia syndrome).

Brady-arrhythmias requiring permanent pacemaker implantation during and after staged Fontan palliation

BACKGROUND

Brady-arrhythmia requiring pacemaker implantation remains one of the Fontan-specific complications before and after total cavopulmonary connection.

METHODS

A retrospective analysis of 620 patients who underwent total cavopulmonary connection between 1994 and 2021 was performed to evaluate the incidence of brady-arrhythmia and the outcomes after pacemaker implantation. Factors associated with the onset of brady-arrhythmia were identified.

RESULTS

A total of 52 patients presented with brady-arrhythmia and required pacemaker implantation. Diagnosis included 16 sinus node dysfunctions, 29 atrioventricular blocks, and 7 junctional escape rhythms. Pacemaker implantation was performed before total cavopulmonary connection (n = 16), concomitant with total cavopulmonary connection (n = 8), or after total cavopulmonary connection (n = 28, median 1.8 years post-operatively). Freedom from pacemaker implantation following total cavopulmonary connection at 10 years was 92%. Twelve patients needed revision of electrodes due to lead dysfunction (n = 9), infections (n = 2), or dislocation (n = 1). Lead energy thresholds were stable, and freedom from pacemaker lead revision at 10 years after total cavopulmonary connection was 78%. Congenitally corrected transposition of the great arteries (odds ratio: 6.6, confidence interval: 2.0-21.5, p = 0.002) was identified as a factor associated with pacemaker implantation before total cavopulmonary connection. Pacemaker rhythms for Fontan circulation were not a risk factor for survival (p = 0.226), protein-losing enteropathy/plastic bronchitis (p = 0.973), or thromboembolic complications (p = 0.424).

CONCLUSIONS

In our cohort of patients following total cavopulmonary connection, freedom from pacemaker implantation at 10 years was 92% and stable atrial and ventricular lead energy thresholds were observed. Congenitally corrected transposition of the great arteries was at increased risk for pacemaker implantation before total cavopulmonary connection. Having a pacemaker in the Fontan circulation had no adverse effect on survival, protein-losing enteropathy/plastic bronchitis, or thromboembolic complications.

Acute Kidney Injury and Renal Replacement Therapy After Fontan Operation

Fontan circulation leads to chronic elevation of central venous pressure. We sought to identify the incidence, risk factors, and survival among patients who developed acute kidney injury (AKI) after the Fontan operation. We retrospectively reviewed 1,166 patients who had Fontan operation/revision at Mayo Clinic Rochester from 1973 to 2017 and identified patients who had AKI (defined by AKI Network criteria) within 7 days of surgery. A total of 132 patients (11%) developed AKI after the Fontan operation with no significant era effect. Of those who developed AKI, severe (grade 3) kidney injury was present in 101 patients (76.5%). Multivariable risk factors for AKI were asplenia (odds ratio [OR] 4.2, p <0.0001), elevated preoperative pulmonary artery pressure (per 1 mm Hg increase, OR 1.04, p = 0.0002), intraoperative arrhythmias (OR 1.9, p = 0.02), and elevated post-bypass Fontan pressure (per 1 mm Hg increase, OR 1.12, p = 0.0007). Renal replacement therapy (RRT) was used in 72 patients (54%), predominantly through peritoneal dialysis (n = 56, 78%). Multivariable risk factors for RRT were age ≤3 years (OR 9.7, p = 0.0004), female gender (OR 2.6, p = 0.02), and aortic cross-clamp time >60 minutes (OR 3.1, p = 0.01). Patients with AKI had more postoperative complications, including bleeding, stroke, pericardial tamponade, low cardiac output state and cardiac arrest, than those without AKI. This resulted in longer intensive care unit stay (39 vs 17 days, p = 0.0001). In-hospital mortality was exceedingly higher among patients with AKI versus no AKI (58%, 76 of 132 vs 10%, 99 of 1,034, p <0.0001); however, there was no significant difference based on the need for RRT. Recovery from AKI was observed in 56 patients (42%). Over 20-year follow-up, patients with AKI had a distinctly higher all-cause-mortality (82%) than those without AKI (35%). It is prudent to identity patients at a higher risk of developing postoperative AKI after Fontan operation to ensure renal protective strategies in the perioperative period. Postoperative AKI leads to substantial short and long-term morbidity and mortality, but the need for RRT does not affect the outcomes.

Liver transplantation in an adult patient with hepatocellular carcinoma following liver cirrhosis as a complication of the Fontan procedure -A case report

Background

Fontan-associated liver disease (FALD) is a hepatic disorder caused by hemodynamic changes and systemic venous congestion following the Fontan procedure. FALD includes liver cirrhosis and hepatocellular carcinoma (HCC), both of which may require liver transplantation (LT). However, the Fontan circulation, characterized by elevated central venous pressure and reduced cardiac output, is a challenging issue for surgeons and anesthesiologists.

Case

We report a living-donor LT for the treatment of HCC. The patient was a 24-year-old male who underwent the Fontan procedure for pulmonary atresia and right ventricle hypoplasia. We focused on maintaining enough blood volume for cardiac output without causing pulmonary edema, as the patient is not well adapted to changes in volume. Owing to a multidisciplinary approach, the surgery was successfully performed without fatal adverse events.

Conclusions

To our knowledge, this is the first case of isolated LT in a recipient who became an adult after having undergone the Fontan procedure.

Surgical palliation of univentricular heart disease in children with Down's syndrome: A systematic review

Objectives

No standard protocol is available for the management of children with Down's syndrome (DS) and a functional single ventricle. This review attempts to determine the outcomes of the single ventricular surgical palliation pathway in high-risk children with DS.

Methods

Several databases were searched using the following MeSH terms: ‘Congenital heart disease’, ‘Atrioventricular septal defect’, ‘Balanced AVSD’, ‘Unbalanced AVSD’, ‘Down's syndrome’, ‘Univentricular repair’, ‘bidirectional Glenn procedure’, and ‘Fontan procedure’. A structured algorithm was used for the selection of studies for an in-depth analysis.

Results

There was no universal agreement on the best surgical approach for unbalanced atrioventricular septal defect in DS. The majority of paediatric cardiac surgeons did not recommend the complete Fontan procedure; conversely, the use of a Glenn shunt (superior cavopulmonary connection) was preferred.

Conclusions

Careful assessment of the suitability for Fontan surgery, including the absence of elevated pulmonary vascular resistance, pulmonary arterial anatomy, and function of the dominant ventricle, is mandatory. A staged surgical procedure ending with complete Fontan repair provides acceptable medium-term results.

Impact of Nesiritide Infusion on Early Postoperative Recovery After Total Cavopulmonary Connection Surgery

OBJECTIVE

The purpose of the study is to compare the effects of nesiritide on the discharge time and pleural effusion in children with total cavopulmonary connection (TCPC), and to provide a more reasonable clinical method for these children.

METHODS

Forty-four who children underwent cavopulmonary connection between January 2016 and 2017 were retrospectively collected, and 5 children were excluded from analysis due to postoperative thrombosis or second Fontan surgery due to high pulmonary hypertension. Thirteen children received nesiritide (3-11 days) plus conventional treatment as the nesiritide group, continuous infusion of nesiritide with the dose of 0.01 ug kg^-1 min^-1. Twenty-six children with the conventional treatment as the conventional treatment group. The length of stay in hospital and the retention time of chest drainage tube were compared between two groups.

RESULTS

There were no significant differences in the time of cardiopulmonary bypass, postoperative ventilation time, ICU time, and vasoactive inotropic drug scores in the two groups. There were no hospital deaths in two groups. The median hospital stay was 20 days in the nesiritide group (11-56 days, means 25 days), and the median length of hospital stay was 28 days in the routine treatment group (9-95 days, means 34 days). There is no statistically significant difference between two groups with regard to the length of stay in hospital (P = 0.281). Regarding the thoracic drainage duration, the median was 17 days (9-55 days, means 22 days) in the nesiritide group and 23 days in the conventional treatment group (7-91 days, means 31 days) (P = 0.294). All the patients had no severe complications such as excessive fluid load, intractable hypotension, and liver or kidney injury.

CONCLUSION

Nesiritide is safe in children who underwent cavopulmonary connection surgery. Compared with the conventional treatment group, postoperative nesiritide is not associated with improved early clinical outcomes after TCPC surgery.

Long Term Consequences of the Fontan Procedure and How to Manage Them

In 1971, Fontan and Baudet described a surgical technique for successful palliation of patients with tricuspid atresia. Subsequently, this technique has been applied to treat most forms of functional single ventricles and has become the current standard of care for long-term palliation of all patients with single ventricle congenital heart disease. Since 1971, the Fontan procedure has undergone several variations. These patients require lifelong management including a thorough knowledge of their anatomic substrate, hemodynamic status, management of rhythm and ventricular function along with multi organ evaluation. As these patients enter middle age, there is increasing awareness regarding the long-term complications and mortality. This review highlights the long-term outcomes of the Fontan procedure and management of late sequelae.

Importance of dynamic central venous pressure in Fontan circulation

We tested our hypotheses that central venous pressure (CVP) shows an excessive increase in response to volume overload in Fontan circulation according to the extent of the reduction in venous capacitance (Cv), and that the maximum CVP after volume loading is associated with hepatic congestion. Changes in CVP after angiography (volume loading) were examined in 40 patients with Fontan circulation and 29 controls with biventricular circulation. CVP significantly increased with angiography in both groups, but the changes were much more evident in the Fontan group than in controls (3.3 ± 2.0 vs. 0.9 ± 1.4 mmHg, p = 0.0003). Multivariate analysis demonstrated that reduced Cv was the only significant determinant of CVP increase, independent of the amount of injected contrast medium, blood volume, pulmonary resistance, and ventricular diastolic stiffness (p < 0.05). Importantly, the use of a venodilator was associated with increased Cv and the resultant suppression of CVP elevation with volume load. In addition, CVP levels both at baseline (p = 0.02) and after volume loading (p = 0.01) were weakly but significantly correlated with the plasma levels of γ-glutamyl transpeptidase, a marker of hepatic congestion; however, multivariate analysis revealed that the CVP level after volume loading was a more important determinant of hepatic congestion. The results of this study highlight the importance of assessing dynamic in addition to static CVP for a better understanding of Fontan circulation. The potential importance of Cv as a therapeutic target for improving Fontan physiology needs further elucidation.

Outcomes of Patients Undergoing Primary Fontan Operation Beyond First Decade of Life

OBJECTIVES

Studies on older patients undergoing primary Fontan operation (FO) are limited, with conflicting results. We review our experience with these patients beyond the first decade of life.

PATIENTS AND METHODS

Between January 2000 and December 2014, a total of 105 patients ≥10 years of age (mean 15.6 ± 4.9, range 10-31, median 15 years) underwent primary FO without a prior bidirectional superior cavopulmonary anastomosis (Bidirectional Glenn [BDG]). Mean preoperative New York Heart Association (NYHA) class was 2.2 ± 0.57.

RESULTS

Operative procedure was extra-cardiac FO in 62 patients (8 were fenestrated). Forty-three had a lateral tunnel FO (26 were fenestrated). There were 11 (10.5%) early deaths. Fourteen of the 94 early survivors experienced prolonged pleural effusions, 7 had arrhythmias, and 2 had thromboembolic events. Two patients underwent Fontan takedown. On univariate analysis, NYHA functional class III, mean pulmonary artery (PA) pressure ≥15 mm Hg, hematocrit ≥60%, preoperative ventricular dysfunction, and atrioventricular valve regurgitation (AVVR) were associated with early mortality. Median follow-up was 78 (mean 88.9 ± 6.3) months. In 94 survivors, 6 (6.4%) late deaths were encountered. At last follow-up, 81 (86.2%) survivors were in NYHA class I. Actuarial survival was 84.7% ± 3.7% at 5, 10, and 15 years.

CONCLUSION

Carefully selected adolescents and young adults can safely undergo the primary FO. However, persistent pleural effusions, arrhythmias, thromboembolic events, and the need for reoperation mandate regular follow-up in such patients. Preoperative NYHA functional class III, mean PA pressure ≧ 15 mm Hg, hematocrit ≥ 60%, ventricular dysfunction, and AVVR were associated with early mortality, suggesting that primary FO should be avoided in such patients.

Effect of Fenestration on Early Postoperative Outcome in Extracardiac Fontan Patients with Different Risk Levels

Although fenestration is used to improve the postoperative course of Fontan patients, the effect of fenestration on the extracardiac Fontan seems controversial especially at early postoperation. One hundred and eighty-three patients from January 2004 to June 2013 undergoing an extracardiac Fontan operation were retrospectively selected for this study. We divided the patients into low risk (93 patients) and high risk (90 patients) groups according to the risk factors recognized by previous studies and then compared the perioperative data between the nonfenestrated and fenestrated patients in each group. In both groups there was no significant difference in preoperative and operative data between the nonfenestrated and fenestrated patients. The postoperative blood oxygen saturation of fenestrated patients was significantly lower (p < 0.01) in each group. In the high risk group the chest tube volume (1153 mL vs. 1739 mL, p = 0.021) and chest tube duration (11.9 days vs. 17.0 days, p = 0.028) of fenestrated patients were lower comparing to nonfenestrated patients, while the chest tube volume and chest tube duration were similar between the nonfenestrated and fenestrated patients in the low risk group. The morbidity and mortality of nonfenestrated and fenestrated patients were similar in both groups (p > 0.05). Although fenestration was associated with lower postoperative oxygen saturation, fenestration showed better postoperative outcomes regarding the chest tube volume and duration for the high-risk patients. Considering the similar early postoperative outcomes of nonfenestrated and fenestrated patients in low risk group, our data indicate that fenestration for the high-risk patients should be performed.

Predictors of poor outcome among children with heterotaxy syndrome: a retrospective review

Objective

To determine predictors of poor outcome in patients with heterotaxy syndrome.

Methods

A retrospective review of children with heterotaxy syndrome, in a single tertiary paediatric cardiology centre, was conducted between 1 January 1997 and 1 January 2014 to determine predictors of poor outcome. Poor outcome was defined as death, cardiac transplantation or New York Heart Association (NYHA) functional class III or IV.

Results

There were 35 patients diagnosed with heterotaxy syndrome, 17 of whom were diagnosed antenatally. 22 patients had right atrial isomerism and 13 had left atrial isomerism. The median age of postnatal diagnosis was 2.5 days old (1 day to 19 months). 12 patients had a poor outcome; 6 patients died, 1 underwent cardiac transplantation and 5 had an NYHA functional class of >III. 5 patients had a biventricular repair and the remaining 30 had a univentricular repair. Type of atrial isomerism, univentricular or biventricular anatomy, severity of atrioventricular valve regurgitation or ventricular dysfunction, obstructed pulmonary venous return, occurrence of arrhythmia and presence of pulmonary atresia did not predict poor outcome. Fetal diagnosis also did not confer a survival advantage. The median duration of follow-up in this cohort was 65 months (2 days to 16.8 years).

Conclusions

Survival for patients with heterotaxy syndrome was 83% over a median follow-up of 65 months. 34% of patients had a poor outcome. None of the variables studied were predictive of death, transplantation or NYHA classification III or IV.

Anesthetic Implications of the Fontan Procedure for Single Ventricle Physiology

The Fontan procedure is the operation of choice for patients considered to be candidates for definitive palliation of single ventricle physiology. Anesthetic technique for the Fontan procedure is not well described in the literature, and the medical and surgical treatment of these patients is rapidly evolving. With an understanding of the anatomy and phys iology of the Fontan patient, a safe and effective anesthetic can be executed. An understanding of the changes that occur during the perioperative period is critical. This article focuses on a review of single ventricle physiology and Fon tan physiology, preoperative assessment and risk factors for the Fontan procedure, intraoperative management, and management of low cardiac output in the postbypass period.

Outcome of Glenn Anastomosis for Heterotaxy Syndrome with Single Ventricle

A retrospective study was undertaken of 157 patients who underwent a Glenn anastomosis between January 1996 and May 2001. Of these, 33 had heterotaxy syndrome: 20 males and 13 females, with a mean age of 1.26 ± 2.8 years. Twenty-five had right atrial isomerism and 5 had left isomerism. A common atrioventricular valve was found in 24 patients, 18 had bilateral superior venae cavae, and 18 had anomalous pulmonary venous return. Repair was carried out in 8 patients with anomalous pulmonary venous return, and pulmonary artery augmentation was performed in 11. Compared to the 124 patients who had a Glenn operation for single ventricle without heterotaxy, there were significantly longer durations of mechanical ventilation, intensive care unit stay, and inotropic support, as well as higher mortality in the heterotaxy group. Heterotaxy syndrome with single ventricle still has a high rate of morbidity and mortality. Patients with severe atrioventricular valve regurgitation are at risk of early death. Complete Fontan circulation may not be possible in all patients, and Glenn anastomosis may be their final palliation.

Contributions of Respiration and Heartbeat to the Pulmonary Blood Flow in the Fontan Circulation

BACKGROUND

In the Fontan circulation, driving forces with respiration, heartbeat, and lower limb muscle pump are relevant. However, the mechanics of these forces has not been proven, and their effects on the Fontan circulation remain unclear.

METHODS

We performed catheter examinations and measured pressure and flow velocity simultaneously in the bilateral pulmonary arteries of 12 Fontan patients 1 year after the operation. The pulmonary pressure and flow velocity data were decomposed into respiratory and heartbeat components by discrete Fourier analysis. We then calculated respiratory and cardiac wave intensity (WI) based on the respiratory and heartbeat components of pressure and flow velocity data.

RESULTS

Respiratory WI formed 2 negative peaks, a backward expansion wave during the inspiratory phase, and then a backward compression wave during the expiratory phase. In 2 phrenic nerve palsy cases and 1 case of a patient on a respirator, respiratory WI showed disturbed patterns and a negative pattern, respectively. Cardiac WI showed 2 or 4 negative peaks, the time phase of which matched that of the atrial contractions.

CONCLUSIONS

WI analysis elucidated that inspiration acts as a sucking driving force and increases the pulmonary blood flow in the Fontan circulation. Respiratory complications compromise efficiency in the Fontan circulation. It was also revealed that the pulmonary blood flow was mutually dammed up and sucked in by increases and decreases in atrial pressure.

Low serum 25-hydroxyvitamin D levels and secondary hyperparathyroidism in Fontan patients

BACKGROUND

Limited data exist on the vitamin D status in Fontan patients. We determined the prevalence and potential risk factors of vitamin D deficiency in this patient subset. Methods and results Data were collected from 27 Fontan patients (55.6% male, mean age 8.1±5.3 years). Protein-losing enteropathy was diagnosed in six patients (22.2%). Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D level of <20 ng/ml. The neutrophil-to-lymphocyte ratio, a marker of systemic inflammation, was calculated. Associations between laboratory measurements and patient characteristics were explored. Mean serum 25-hydroxyvitamin D level was 14.1±10.4 ng/ml. Vitamin D deficiency was found in 19/27 patients (70.3%). Only skin type was associated with vitamin D deficiency (p=0.04). Hyperparathyroidism was present in 5/21 (23.8%) patients, and was more prevalent in patients with protein-losing enteropathy (p<0.001). Parathyroid hormone levels correlated with parameters of systemic inflammation (neutrophil-to-lymphocyte ratio: r=0.484, p=0.026; relative lymphocyte count: r=-0.635, p=0.002). Vitamin D supplementation significantly increased serum 25-hydroxyvitamin D levels (p<0.0001), and was accompanied by a reduction in parathyroid hormone concentrations (p=0.032).

CONCLUSIONS

A high prevalence of vitamin D deficiency was found among Fontan patients, independent of age, time after Fontan procedure, ventricular morphology, and presence of protein-losing enteropathy. A potentially important link between parathyroid hormone levels and systemic inflammation is suggested.

Screening and Treatment of Intestinal Rotational Abnormalities in Heterotaxy: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess the role of screening and prophylactic surgery for intestinal rotational abnormalities (IRAs) in asymptomatic patients with heterotaxy.

STUDY DESIGN

PubMed, Embase, and Cinahl were searched electronically to determine the overall incidence of IRAs in heterotaxy; the detection rate of IRAs associated with screening; the incidence of midgut volvulus in patients without screening; and the incidence of morbidity and mortality after prophylactic and emergency Ladd procedures. Relevant data were computed with a meta-analysis of proportions. Between-study heterogeneity was assessed with the I(2) statistic.

RESULTS

From 276 papers identified, 24 studies with a total of 1433 patients with heterotaxy were included for systematic review. No randomized study was identified. True incidence of IRA in heterotaxy could not be ascertained through meta-analysis. In patients who underwent screening, the incidence of IRA was 58%. Acute midgut volvulus occurred in 5.8% of those who did not undergo screening. Postoperative mortality after Ladd procedure mainly was associated with cardiac insufficiency, and overall it was significantly greater in the emergency group compared with the prophylactic group (18% vs 5.6%). The complication rate also was greater in case of emergency vs prophylactic abdominal surgery (27% vs 16%); adhesional small bowel obstruction was the most common complication overall (6%).

CONCLUSION

The screen-detected incidences of IRA and acute midgut volvulus were significantly greater in heterotaxy than the normal population. Prophylactic Ladd procedure was associated with less morbidity and mortality compared with emergency surgery. A long-term prospective randomized trial is needed to define the indication for screening and prophylactic treatment of IRA in heterotaxy.

An unusual occurrence: a case of venous thromboembolism in pregnancy associated with heterotaxy syndrome

BACKGROUND

Heterotaxy is a relatively uncommon congenital anomaly that is usually diagnosed incidentally on imaging studies in adults. We present an unusual case of venous thromboembolism in a 26 year old pregnant female with Heterotaxy syndrome.

CASE PRESENTATION

A 26 year-old pregnant female at 13 weeks gestation suffered cardiac arrest with successful cardiac resuscitation and return of spontaneous circulation. The cardiac arrest was secondary to massive pulmonary embolism requiring thrombolytic therapy and stabilization of hemodynamics. She had extensive evaluation to determine the etiology for the pulmonary embolism and was noted to have an anatomic variation consistent with heterotaxy syndrome on imaging studies. After thrombolysis the patient was treated with UFH and then switched to enoxaparin without complication until 25 weeks of gestation when she experienced worsening abdominal pain with associated headaches, lightheadedness and elevated blood pressures needing elective induction of labor. The infant died shortly after delivery. The anticoagulation was continued for additional 3 months and she was subsequently placed on low dose aspirin to prevent recurrent venous thromboembolic episodes. She is currently stable on low dose aspirin and is into her third year after the venous thromboembolism without any recurrence.

CONCLUSION

To our knowledge, this is the first reported case of venous thromboembolism in pregnancy associated with heterotaxy syndrome. A discussion on pathophysiology of venous thromboembolism in pregnancy and heterotaxy syndrome has been undertaken along with treatment approach in such situations.

Pediatric split liver transplantation after Fontan procedure in left isomerism combined with biliary atresia: a case report

LI is a subset of the heterotaxy syndrome and a rare birth defect that involves the heart and other organs. It can be combined with extracardiac abnormalities, especially BA. CHD can be associated with LI in up to 15% of cases, although it is rare in BA. Pediatric LT for a child with ESLD due to BA combined with LI and CHD is a challenging issue for a transplant surgeon. Herein, we report a successful split LT on a three-yr-old boy with LI who survived after a Fontan procedure due to single ventricle, but who suffered from HPS associated with BA.

Aldosterone-cortisol imbalance immediately after fontan operation with implications for abnormal fluid homeostasis

Abnormal water metabolism is frequently observed after Fontan surgery. We hypothesized that patients' adrenal hormones show unique responses immediately after Fontan operation and that such a hormonal profile is related to postoperative hemodynamics and water imbalance. Twenty-eight patients who underwent a Fontan operation (n = 16) or a non-Fontan type operation (n = 12; controls) under cardiopulmonary bypass were studied. Postoperative urine cortisol and aldosterone levels were measured daily to minimize the influence of circadian rhythms and temporal hemodynamic variations. Cortisol excretion was markedly elevated on postoperative day (POD) 0 in controls, consistent with a stress-induced cortisol response. Cortisol excretion was not high on POD 0 in Fontan patients and was markedly lower than that in the controls (444 ± 150 vs 34 ± 6 μg/m(2)/day, p <0.05), indicating an adrenal insufficiency status. Conversely, aldosterone levels were significantly higher in Fontan patients than in controls immediately after surgery and remained so thereafter. The cortisol-to-aldosterone ratio was significantly lower in Fontan patients on POD 0 (p <0.05 vs controls); low cortisol-to-aldosterone ratios were associated with a longer pleural drainage duration and intensive care unit stay. Daily cortisol and aldosterone levels were significantly associated with postoperative hemodynamics; low cortisol levels correlated with low cardiac and urine outputs, whereas high aldosterone levels correlated with low cardiac output and increased blood pressure and central venous pressure. Thus, aldosterone-to-cortisol imbalance occurred specifically after the Fontan operation. This unique hormonal profile significantly affected patients' postoperative water balance and hemodynamics. Modulation of the adrenal hormone could be useful for reducing postoperative complications after the Fontan operation.

Risk factors for major adverse events late after Fontan palliation

OBJECTIVE

Risk factors for major adverse events late after Fontan palliation are unknown. Prior studies have suggested ventricular function and morphology as important risk factors. The aim of this study is to (1) characterize the late major adverse event profile in adult Fontan patients and (2) identify additional risk factors that may contribute to adverse outcomes.

DESIGN AND SETTING

A retrospective review of all adult patients >15 years post-Fontan seen at a tertiary academic center was conducted. Clinical, laboratory, cardiac data, and abdominal imaging were collected via chart review. Major adverse events (death, cardiac transplantation, or listing) were identified, and timing of events was plotted using Kaplan-Meier methods. Univariate and multivariate logistic regression was used to determine independent predictors of late-term events.

RESULTS

A total of 123 adult Fontan patients were identified (mean time post-Fontan 22.4 years [±4.4]). Major adverse events occurred in 19/123 patients (15%). In this 15-year survivor cohort, transplant-free survival rates were 94.6%, 82.9%, and 59.8% at 20, 25, and 30 years postoperation, respectively. Modes of death were Fontan failure with preserved function (4), congestive heart failure with decreased function (2), sudden death (2), thromboembolic event (1), post-Fontan conversion (2), and posttransplant (2). No differences in adverse outcomes were found based on morphology of the systemic ventricle, Fontan type, or systolic ventricular function. On the other hand, features of portal hypertension (OR 19.0, CI 4.7-77.3, P < .0001), presence of a pacemaker (OR 13.4, CI 2.6-69.8, P = .002), and systemic oxygen desaturation (OR 0.86, CI 0.75-0.98, P = .02) were risk factors for major adverse events in the multivariate analysis.

CONCLUSIONS

In adult Fontan patients surviving >15 years post-Fontan, portal hypertension, oxygen desaturation, and need for pacemaker were predictive of adverse events. Traditional measures may not predict late-term outcomes in adult survivors; further study of the liver's role in late outcomes is warranted.

Comparison of fenestrated and nonfenestrated patients undergoing extracardiac Fontan

BACKGROUND

The purpose of this study is to compare morbidity and mortality between fenestrated (F, 61 patients) and nonfenestrated (NF, 54 patients) extracardiac Fontan patients during two eras from July 1995 to December 2010: era 1(1995 to 2004) and era 2 (2005 to 2010).

METHODS

Variables evaluated included morphology, hemodynamics, chest tube volume and duration, intensive care and hospital stay, oxygen saturation, neurologic events, rhythm, and readmissions for chylous effusions. Follow-up in 114 hospital survivors was longer in the nonfenestrated cohort (F, 5.0 ± 3.3 years; NF, 7.1 ± 4.6 years; p < 0.005).

RESULTS

Cohorts were similar in body size, morphology, and hemodynamics. Fenestration in hypoplastic left heart syndrome was appreciatively higher in era 2. Bypass time (F, 69 ± 27 minutes; NF, 57 ± 21 minutes) and conduit size (F, 18.8 mm; NF, 19.1 mm) were similar. There was 1 early nonfenestrated Fontan death (1 of 54; 2%) and 4 late deaths (F, 2 of 61, 5%; NF, 2 of 53, 4%; p = 0.86). Room air saturation was higher in NF patients (F, 89%; NF, 94%; p < 0.05). Total chest tube volume was similar, but fenestration was associated with greater chest tube drainage among hypoplastic left heart patients (HLHS, 5,582 ± 3,286 mL; non-HLHS, 3,405 ± 2,533 mL; p = 0.06; odds ratio; 2.0). Readmission to treat chylous effusions, loss of sinus rhythm, actuarial freedom from death, all neurologic events, pacemaker insertion, and Fontan takedown were similar in both cohorts.

CONCLUSIONS

Fenestration was associated with lower discharge oxygen saturations, but late outcomes in fenestrated and nonfenestrated patients are equivalent.

Quantitative evaluation of hemodynamics in the Fontan circulation: a cross-sectional study measuring energy loss in vivo

Flow energy loss (EL) at the Fontan anastomosis has been thought to reflect flow efficiencies and to influence on hemodynamics in the Fontan circulation and has been often discussed in numerical studies. However, in vivo EL measurements have to date not been reported. We directly measured EL in the Fontan circulation and examined the relationship between the structural configuration and EL, as well as the influence of EL, on the hemodynamics in the Fontan circulation. We performed a catheterization study measuring simultaneous pressure and flow velocity to calculate EL in nine patients (mean age 2.3 ± 0.3 years) 1 year after the Fontan procedure. The measured EL was 9.66 ± 8.50 mW. One patient with left pulmonary artery stenosis recorded the highest EL (17.78 mW), and one patient with bilateral superior vena cava and left phrenic nerve palsy recorded the second highest EL (14.62 mW). EL significantly correlated with time constant tau and weakly with max-dp/dt during the isovolumic diastolic phase (r = 0.795 and -0.574, respectively). EL also correlated with max-dp/dt during the isovolumic systolic phase (r = 0.842) but not with ejection fraction or systemic blood flow (r = 0.384 and -0.034, respectively). In conclusion, inefficient structural configuration and phrenic nerve palsy seem to be related with increased in EL at the Fontan anastomosis. Although these preliminary findings also suggest that EL is associated with an impaired relaxation of the ventricle, a long-term study with a large population is warranted to reach such a definitive conclusion.

Insights into the evolution of myocardial dysfunction in the functionally single right ventricle between staged palliations using speckle-tracking echocardiography

BACKGROUND

The long-term prognosis of hypoplastic left heart syndrome is limited by progressive right ventricular dysfunction. The aim of this study was to determine the trends in single right ventricular systolic function between staged palliative surgeries using speckle-tracking and conventional echocardiography.

METHODS

There were 76 patients with functionally single right ventricles at the (1) pre-Norwood (n = 26), (2) pre-bidirectional cavopulmonary anastomosis (BCPA; n = 19), (3) pre-Fontan (n = 16), and (4) post-Fontan (n = 15) stages, compared with 30 controls of similar ages. Speckle-tracking-derived longitudinal and circumferential strain and strain rate, postsystolic strain index, and mechanical dyssynchrony index were compared with conventional measures of ventricular function. Differences between stages were analyzed using analysis of variance (P < .05).

RESULTS

Strain rate was highest at the pre-Norwood stage and decreased at the other stages (longitudinal P < .0001, circumferential P = .0002), as opposed to controls, in whom strain rate was maintained. Longitudinal strain was significantly decreased at the pre-BCPA stage compared with the pre-Norwood stage (P = .004), but circumferential strain was maintained, resulting in a corresponding decrease in the ratio of longitudinal to circumferential strain, which failed to resemble that of controls. Longitudinal (P = .003) and circumferential (P = .002) postsystolic strain indices were greatest at the pre-BCPA stage.

CONCLUSIONS

A decline in contractility occurred at the pre-BCPA stage. Although there was evidence of adaptation of the single right ventricle, this failed to resemble the normal left ventricle and may be insufficient to handle the chronic volume load or insult from previous surgery. These findings suggest an intrinsic inability of the single right ventricular myocardium to fully adapt to chronic systemic pressures.

Modulation of pulmonary vascular resistance as a target for therapeutic interventions in Fontan patients: focus on phosphodiesterase inhibitors

Despite advancements in surgical techniques over the past 20 years, Fontan patients have decreased exercise capacity as a consequence of an inherent inability to adequately increase cardiac output during exercise. They are also affected by several complications that are associated with considerable morbidity and mortality. As the systemic and pulmonary circulations are placed in series without a subpulmonary ventricle propelling blood through the pulmonary vasculature, the systemic venous pressure and the respiratory mechanics are the only forces driving pulmonary blood flow. In Fontan circulation, pulmonary vascular resistance is the single most important factor involved in the limitation of cardiac output and treatments able to decrease pulmonary vascular resistance might conversely improve cardiac output and exercise capacity. In this article we discuss the initial experience with the use of sildenafil in Fontan patients and we discuss the possible mechanisms through which sildenafil might positively act in Fontan circulation.

Atrioventricular valve repair for patient with heterotaxy syndrome and a functional single ventricle

Heterotaxy syndrome is a mortality risk factor for patients with complex heart disease. These patients often have common atrioventricular valve (CAVV) morphology and significant atrioventricular valve regurgitation - yet another mortality risk factor in congenital heart disease. Thus, patients with both heterotaxy syndrome and atrioventricular valve regurgitation are at highest risk of mortality. A large number of patients with heterotaxy syndrome have CAVV and a functional single ventricle. These patients are more difficult to operate than patients with biventricular morphology because in the former, the CAVV is often less adapted to systemic afterload than the mitral valve. Herein, we present the results of atrioventricular valve repair surgeries performed at the Okayama University Hospital on patients with heterotaxy syndrome, atrial isomerism, and a functional single ventricle. In addition, we review the current literature in this typically challenging patient population. In-depth understanding of reasonable management strategies and resolution of technical issues will help guide surgeons during this procedure.

Impact of the evolution of the Fontan operation on early and late mortality: a single-center experience of 405 patients over 3 decades

BACKGROUND

Postoperative mortality has decreased in patients undergoing the Fontan operation, and the determinants of such mortality may also have changed significantly.

METHODS

We conducted a study intended to focus on clarifying the determinants of mortality in 405 consecutive patients who had undergone a Fontan operation (62 patients after an atriopulmonary connection, 105 after an intra-atrial rerouting, and 238 patients after an extracardiac rerouting) between 1979 and 2010.

RESULTS

The overall 1-year, 5-year, 10-year, and 15-year rates of survival were 87.1%, 84.6%, 83.4%, and 81.6%, respectively, and the type of procedure as well as heterotaxy syndrome, ventricular ejection fraction, and atrioventricular valve repair at the time of the Fontan operation were independent predictors of overall mortality (p < 0.05 for all). Heterotaxy syndrome and atrioventricular (AV) valve repair were independent predictors of early (less than 6 months postoperative) mortality and the type of procedure was an independent predictor of late (6 or more months postoperative) mortality (p < 0.05 to 0.01). In the era of intra-atrial rerouting, heterotaxy syndrome was the only independent predictor of total, early, and late mortality (p < 0.05 for all), whereas a low ejection fraction, AV valve repair, and repair of a total anomalous pulmonary vein connection, rather than heterotaxy syndrome, were independent predictors of total or early mortality or both (p < 0.05 for all) in the era of extracardiac rerouting.

CONCLUSIONS

Even in the modern era of extracardiac rerouting in the Fontan operation, a low ventricular ejection fraction, AV valve dysfunction, or a total anomalous pulmonary vein connection remain significant risk factors for mortality in patients with a single-ventricle physiology.

Long-term outcome after atrioventricular valve surgery following modified Fontan operation

OBJECTIVE

The objective of this study was to evaluate the early and late results of atrioventricular valve surgery after Fontan operation.

BACKGROUND

Atrioventricular valve regurgitation is a known perioperative risk factor for Fontan operation. There are limited data on the outcomes of late atrioventricular valve surgery following Fontan operation.

METHODS

Patients who underwent atrioventricular valve surgery following Fontan procedure were identified from the Mayo Clinic Fontan database. Medical records were reviewed for pre-operative, operative, and post-operative clinical and haemodynamic data. All patients not known to be deceased were sent health status questionnaires.

RESULTS

A total of 61 patients (28 females) underwent atrioventricular valve surgery following Fontan procedure. The median age at atrioventricular valve surgery was 14 years. The median duration between Fontan and atrioventricular valve surgery was 4.7 years. Median follow-up was 9 years. There were a total of 32 (52%) deaths with 8 (13%) within 30 days of surgery. The 5-, 10-, and 15-year survival rates were 67%, 57%, and 45%, respectively. On follow-up, 44 of 61 (72%) had arrhythmias, 21 of 29 (72%) were symptomatic, and 12 of 61 (20%) developed protein-losing enteropathy. On multivariate analysis, reduced ventricular function and development of protein-losing enteropathy were associated with decreased survival.

CONCLUSION

Atrioventricular valve surgery after Fontan procedure is associated with substantial late morbidity and mortality. Atrioventricular valve surgery in this cohort of patients portends poor long-term outcome and is associated with a high incidence of protein-losing enteropathy. Reduced ventricular function and development of protein-losing enteropathy were associated with decreased survival.

Intracardiac cavopulmonary connection in patients with univentricular heart using intra-atrial lateral tunnel and intra-atrial conduit techniques

BACKGROUND

In this study, we analyzed the time course of hemodynamic efficiency and follow-up in Fontan candidates who underwent the bidirectional Glenn procedure for staged intracardiac cavopulmonary connection (ICPC).

METHODS

Between 1991 and 2008, 52 patients with univentricular heart (mean age, 3.3 years; range, 2-8 years; 27 female patients [51.9%]) underwent ICPC. The cardiac malformations were as follows: tricuspid atresia, 25 cases (48.0%); common ventricle, 16 cases (30.7%); and pulmonary atresia with intact ventricular septum, 11 cases (21.1%). The intracardiac cavopulmonary procedure was indicated for all 52 cases. In 42 patients (80.7%), an intra-atrial lateral tunnel was constructed with a bovine pericardium patch. In the last 10 consecutive cases (19.3%), we performed a modified surgical technique in which we implanted an intra-atrial corrugated bovine pericardium tube sutured around the superior and inferior vena cava ostium. In all cases, a 4-mm fenestration was made to reduce the intratunnel pressure. All 52 patients had previously undergone a Glenn operation.

RESULTS

There were 2 hospital deaths (3.8%) and no recorded late deaths. During the follow-up, all patients were medicated with antiplatelet drugs. To evaluate the hemodynamic performance, we used Doppler echocardiography, computed tomography, and magnetic nuclear resonance studies. There were no prosthesis thromboses during this followup period. To evaluate cardiac arrhythmias, we conducted a Holter study. The last 10 patients with an intra-atrial conduit (IAC) presented with sinus rhythm and no arrhythmias during the last 4 years. The 50 surviving patients (96.1%) have been followed up for 6 to 204 months; all these patients are free of reoperation.

CONCLUSION

The Glenn operation, which is performed at an early age, prepares the pulmonary bed to receive the ICPC. The midterm results of the intracardiac Fontan procedure seem to be good. The modified surgical procedure (IAC) can be a good alternative technique to the Fontan procedure in suitable patients.

In situ pericardial extracardiac lateral tunnel Fontan operation: fifteen-year experience

BACKGROUND

The study purpose is to evaluate the long-term outcome of the in situ pericardial extracardiac lateral tunnel Fontan operation.

METHODS

From June 1994 to August 2009, 160 patients with single ventricle (boys, n = 96, 60%, median age = 39 months, mean weight 15.5 kg) underwent the pedicled pericardial extracardiac lateral tunnel operation. Patients' charts were reviewed for perioperative and long-term follow-up data, outcome, and mortality. The potential growth of these tunnels was evaluated.

RESULTS

The main diagnoses included tricuspid atresia (n = 44, 27%); double-outlet right ventricle (n = 29, 18%), and hypoplastic left heart syndrome (n = 26, 16%). The mean follow-up was 6.5 ± 3.7 years (range: 0.1-15 years). There were 2 (1.3%) operative and 6 (3.7%) late deaths. Actuarial survival at 14 years was 93%. Early complications included prolonged effusions (n = 35, 22%), chylothorax (n = 5, 3.1%), readmissions (n = 35, 22%), cerebrovascular accidents (n = 8, 5%), contralateral phrenic nerve palsy (n = 1, 0.8%), and transient arrhythmias (n = 5, 3.1%). No pacemaker was needed. Late complications included tunnel stenosis (n = 3, 1.8%) managed with balloon dilatation and stenting in 2 patients and surgical revision in 1; tunnel thrombosis (n = 2, 1.2%) causing death in both patients; and protein losing-enteropathy (n = 4, 2.5%). Follow-up echocardiography of 10 patients showed laminar flow, no turbulence/gradient at the inferior vena cava and mid-tunnel levels. The diameter indexed to body surface area showed growth, reduction, or no change depending on flow demands.

CONCLUSIONS

The construction of the extracardiac lateral tunnel Fontan conduit using viable pedicled pericardium is a relatively simple, durable, and safe operation. Long-term follow-up confirms low morbidity and mortality. Fenestration is unnecessary in most patients. This viable tunnel adapts to physiologic flow demands.

The effect of bosentan in patients with a failing Fontan circulation

OBJECTIVES

To investigate the effect of bosentan in patients with a failing Fontan circulation.

DESIGN

A multicentric open label, non-controlled study.

SETTING

5 tertiary care centres for congenital cardiology.

PATIENTS

We included 10 patients with a failing Fontan circulation. Their median age at inclusion was 12.12 years, with a range from 4.41 to 33,41 years. The median interval between the Fontan operation and inclusion was 7.84 years, with a range from 1.96 to 12,18 years. Participants received half the usual dose of bosentan for 4 weeks, and then the full dose for a further 12 weeks. MAIN MEASURES OF OUTCOMES: We assessed saturations of oxygen at rest and during exercise, using a 6 minutes walk test, at baseline, and during and after 16 weeks of treatment. At each visit, we assessed blood chemistry and hepatic function, and asked the patients to complete a questionnaire concerning quality of life. All medical events and possible side effects were recorded.

RESULTS

Of the cohort, 1 patient withdrew. The changes in saturations of oxygen, exercise performance, and scores for the questionnaire did not reach statistical significance for the whole group. We noted, nonetheless, that saturations of oxygen and/or exercise capacity improved in 5 of the patients. This was further confirmed when those patients deteriorated again when the drug was discontinued.

CONCLUSIONS

Our study failed to show significant improvement after 3 months of treatment with bosentan in a small group of patients with failing Fontan circulations. Some individuals, nonetheless, did improve. When planning larger trials, it would be better to identify those patients who might potentially benefit from the treatment prior to commencing the trial.

Impact of spironolactone on endothelial function in patients with single ventricle heart

BACKGROUND

Mid-term survivors of the Fontan procedure are at risk for progressive heart failure, and endothelial dysfunction is thought to contribute to this process. Aldosterone antagonism has been shown to improve survival in adults with heart failure and the effects are mediated in part by changes in endothelial function. In the present study, we sought to determine if a short course of spironolactone improves endothelial function and alters serum cytokine profiles in adolescents and adults with single ventricle heart.

METHODS

Subjects had baseline assessment of flow-mediated dilation and cytokine profiles (C-reactive protein, interleukin-6, interleukin-1b, interleukin-10, tumor necrosis factor-alpha). They were started on spironolactone 25 mg once a day and uptitrated to 50 mg once daily. After 4 weeks, flow-mediated dilation and cytokine profiles were re-evaluated.

RESULTS

Ten subjects (median age 28 years) were enrolled and completed the protocol. The median flow-mediated dilation at baseline was 9.1% and did not change significantly after 4 weeks of spironolactone 7.6%, P = .46. There was mild elevation in serum cytokine profiles and only interleukin-1b decreased significantly with therapy, 0.39 to 0.23 pg/mL, P = .04.

CONCLUSIONS

In this small study, a short course of spironolactone did not improve endothelial function or alter the majority of serum cytokine levels. Whether single ventricle patients might realize other potential benefits of aldosterone antagonism such as reduced cardiac fibrosis remains to be determined.

Acute kidney injury in an infant after cardiopulmonary bypass

The infant who develops acute kidney injury (AKI) after cardiopulmonary bypass (CPB) surgery presents unique challenges and opportunities to the clinician and to the investigator interested in the study of AKI pathophysiology. Infants do not have many of the comorbid conditions that confound CPB outcome studies of adults. Because the timing of the AKI event is known in this clinical setting, collaboration between cardiology intensivists, nephrologists, and perfusion technologists is essential to minimize the impact of CPB on the kidney. Early institution of ultrafiltration in the operating room and renal replacement therapy in the postoperative period may decrease the proinflammatory milieu and its resultant systemic effects. In addition, early initiation of renal replacement therapy to prevent fluid overload may result in improved infant outcomes.

Factors Influencing Survival in Patients after Bidirectional Glenn Shunt

Clinical characteristics, echocardiographic values, and catheterization data of 45 patients with a functional univentricular heart who had a bidirectional Glenn shunt instituted between November 1994 and October 2006 were retrospectively reviewed. Median age at operation was 20 months (range, 9 months to 19 years). Median follow-up time after the bidirectional Glenn operation was 4 years (range, 1 day to 11 years). The early mortality rate was 4/45 (8.9%); overall mortality was 24.4%. Actuarial survival after a bidirectional Glenn shunt was 73% ± 8% at 5 years and 55% ± 17% at 10 years. In multivariate Cox proportional hazards analysis, heterotaxy syndrome and systemic right ventricle were independent predictors of mortality after the bidirectional Glenn shunt. Age at operation, oxygen saturation, previous surgery, a pulsatile Glenn shunt, cardiopulmonary bypass, postoperative pulmonary artery pressure, bilateral superior venae cavae, and Nakata index were not predictive of mortality. The presence of heterotaxy syndrome and systemic right ventricle in patients with a functional univentricular heart should lead to aggressive investigation and management strategies.

Long-term survival, modes of death, and predictors of mortality in patients with Fontan surgery

BACKGROUND

To better define determinants of mortality in patients with univentricular physiology, a database registry was created of patients born in 1985 or earlier with Fontan surgery who were followed up at Children's Hospital Boston.

METHODS AND RESULTS

A total of 261 patients, 121 of whom (46.4%) were women, had a first Fontan surgery at a median age of 7.9 years: right atrium-to-pulmonary artery connection in 135 (51.7%); right atrium to right ventricle in 25 (9.6%); and total cavopulmonary connection in 101 (38.7%). Over a median of 12.2 years, 76 (29.1%) died, 5 (1.9%) had cardiac transplantation, 5 (1.9%) had Fontan revision, and 21 (8.0%) had Fontan conversion. Perioperative mortality decreased steadily over time and accounted for 68.4% of all deaths. In early survivors, actuarial freedom from death or transplantation was 93.7%, 89.9%, 87.3%, and 82.6% at 5, 10, 15, and 20 years, respectively, with no significant difference between right atrium to pulmonary artery versus total cavopulmonary connection. Late deaths were classified as sudden in 7 patients (9.2%), thromboembolic in 6 (7.9%), heart failure-related in 5 (6.7%), sepsis in 2 (2.6%), and other in 4 (5.2%). Most sudden deaths were of presumed arrhythmic origin with no identifiable predictor. Independent risk factors for thromboembolic death were lack of antiplatelet or anticoagulant therapy (hazard ratio [HR], 91.6; P=0.0041) and clinically diagnosed intracardiac thrombus (HR, 22.7; P=0.0002). Independent predictors of heart failure death were protein-losing enteropathy (HR, 7.1; P=0.0043), single morphologically right ventricle (HR, 10.5; P=0.0429), and higher right atrial pressure (HR, 1.3 per 1 mm Hg; P=0.0016).

CONCLUSIONS

In perioperative survivors of Fontan surgery, gradual attrition occurs predominantly from thromboembolic, heart failure-related, and sudden deaths.

Thromboembolism and the role of anticoagulation in the Fontan patient

Among factors contributing to morbidity and failure of the Fontan circulation is the group of events referred to as thromboembolic complications. These events have been variously attributed to low flow states, stasis in the venous pathways, right-to-left shunts, blind cul-de-sacs, prosthetic material, atrial arrhythmias, and hypercoagulable states. Numerous investigations, most retrospective, have been undertaken to characterize thromboembolic events; describe the frequency and circumstances of these occurrences; and relate the risk of these events to patient, surgical, hemodynamic, and hematologic factors. Practices vary widely with respect to strategies of prophylactic anticoagulation in the hopes of minimizing the occurrence and morbidity of thromboembolism after Fontan operations. Review of the literature suggests that the factors associated with thromboembolic events after Fontan operations likely represent a complex field of biologic factors with multiple interactions. It is unlikely that a single agent will represent the solution to this complex problem.

Heterotaxia syndromes and their abdominal manifestations

PURPOSE OF REVIEW

Children with heterotaxia often have abnormalities of intestinal rotation, some of which may predispose to midgut volvulus. This review summarizes the literature and proposes an individualized approach to the patient based on symptoms and findings on gastrointestinal imaging.

RECENT FINDINGS

This report reviews the types of heterotaxia syndromes and the debate surrounding the optimal management of the associated intestinal rotational abnormalities. Recent publications suggest that not all rotational abnormalities predispose to volvulus and that the natural history of rotational abnormalities in asymptomatic patients with heterotaxia is relatively benign. On the basis of these findings, an algorithm for the management of intestinal rotational abnormalities is proposed.

SUMMARY

Malrotation and midgut volvulus is a life-threatening complication. Children with heterotaxia and symptoms suggestive of a proximal intestinal obstruction require urgent investigation and surgical treatment. Asymptomatic children require close clinical follow-up and urgent investigation of gastrointestinal symptoms.