Outcomes of patients with single ventricle physiology undergoing cavopulmonary palliations depend on pulmonary vascular resistance (PVR) and have been suggested to be adversely affected by living at elevated altitude. We compared the pulmonary hemodynamic data in correlation with postoperative outcomes at the 3 centers of Denver, Edmonton, and Toronto at altitudes of 1604, 668, and 103 meters, respectively.
Hemodynamic data at pre-bidirectional cavopulmonary anastomosis (BCPA) and pre-Fontan catheterization between 1995 and 2007 were collected. Death from cardiac failure or heart transplantation in the same period was used to define palliation failure.
There was no significant correlation between altitude (ranged from 1 to 2572 meters) and PVR, pulmonary artery pressure (PAP) or transpulmonary gradient (TPG) at pre-BCPA and pre-Fontan catheterization. BCPA failure occurred in 11 (9.2%) patients in Denver, 3 (2.9%) in Edmonton, and 34 (11.9%) in Toronto. Fontan failure occurred in 3 (6.1%) patients in Denver, 5 (7.2%) in Edmonton, and 11 (7.0%) in Toronto. There was no significant difference in BCPA and Fontan failure among the 3 centers. BCPA failure positively correlated with PVR and the presence of a right ventricle as the systemic ventricle. Fontan failure positively correlated with PAP and TPG.
Moderate altitude is not associated with an increased PVR or adverse outcomes in patients with a functional single ventricle undergoing BCPA and the Fontan operation. The risk factors for palliation failure are higher PVR, PAP, and TPG and a systemic right ventricle, but not altitude. Our study reemphasizes the importance of cardiac catheterization assessments of pulmonary hemodynamics before BCPA and Fontan operations.
The bidirectional Glenn procedure (BDG) is a routine intermediary step in single-ventricle palliation. In this study, we examined risk factors for death or transplant and failure to reach Fontan completion after BDG in patients, who had previously undergone stage one palliation (S1P).
All patients at our institution, who underwent BDG following S1P between 2002 and 2009 (n = 194), were included in the analysis.
Transplant-free survival through 18 months post BDG was 91%. Univariable competing risk analyses showed atrioventricular valve regurgitation (AVVR) >mild, age ≤3 months at BDG, ventricular dysfunction >mild, and prolonged hospital stay after S1P to be associated with increased risk of death or orthotopic heart transplant. Multivariable competing risk analysis through 5 years of follow-up showed >mild AVVR (hazard ratio (HR) 7.5, 95% confidence interval (CI) 3.0–18.8), prolonged hospitalization after S1P (HR 4.5, 95% CI 1.8–11.5), and age ≤3 months at BDG (HR 6.8, 95% CI 2.3–20.0) to be independent risk factors for death or transplant. Concomitantly, >mild AVVR and age ≤3 months were independently associated with an overall decreased rate of Fontan completion.
Pre-BDG AVVR, age ≤3 months at time of BDG, and prolonged hospitalization after S1P are independently associated with decreased successful progression of staged palliation in midterm follow-up after BDG.
Congenital heart disease; CHD; Hypoplastic left heart syndrome; Outcomes; Pediatric
The complete Fontan circulation is the definite palliation for many complex congenital cardiac lesions. After bi-directional Glenn anastomosis (BDG), two well-established techniques – intracardiac tunneling and extracardiac prosthesis – are available for completion, although the choice of technique is still a matter of debate.
Material and methods
We retrospectively reviewed the surgical and clinical records of patients with single ventricle physiology, who underwent intracardiac (group I) or extracardiac (group II) Fontan palliation after BDG.
Complete data were available in 72 patients. Thirty-eight patients received intracardiac (median weight: 12.6 kg) and 34 patients extracardiac repair (median weight: 15.6 kg). Patients with intracardiac tunneling had longer cardiopulmonary bypass (CBP) time (170 min vs. 104 min; p < 0.001), longer ventilatory (39 h vs. 21 h; p = 0.009) and longer inotropic support (48 h vs. 10 h; p < 0.001). Ventilatory and inotropic support were dependent on CPB (r = 0.69 and r = 0.637) and on aortic cross-clamping (r = 0.785 and r = 0.705 only group I), but not dependent on age, weight or pulmonary artery pressure (PAP).
Both techniques are feasible without perioperative mortality. Normally developed children with good hemodynamics after BDG received an elective extracardiac procedure without fenestration later. Patients with developmental retardation, severe progressive cyanosis, myocardial dysfunction, or moderate to severe atrio-ventricular valve insufficiency are scheduled for an earlier intracardiac baffle repair with routine fenestration, as they are at higher risk. Prolonged CPB and aortic cross-clamping times adversely impact the early postoperative course. Further strategies must be developed to avoid these effects, particularly in the patient group at higher imminent risk.
Fontan; univentricular heart
The success of a Fontan circulation depends on several factors including low pulmonary vascular resistance. Pulmonary vascular resistance rises in response to hypoxia. Hypoxia is associated with altitude. Therefore, we wondered whether altitude is a risk factor for early failure after the Fontan operation. The aim was to test this hypothesis.
Data were obtained from all published series of 'total cavopulmonary' Fontan operations since 1990. The early failure rate from each series and the altitude of the respective cities were recorded. Early failure was defined as death, takedown of Fontan, or transplantation during the same hospital admission. The association between altitude and failure rate was investigated by rank correlation and logistic regression.
24 series were identified from centres situated at altitudes ranging from sea level to 520 metres. The plot of failure rate versus altitude suggests that failure rate increases with altitude. Logistic regression did not fit the data adequately. This was possibly due to the influence of unmeasured and unknown factors affecting the results, as well as the fact that centres were not randomly chosen but were self-selected by virtue of publishing their results. However, Spearman's rank correlation was 0.74 (p = 0.001).
The early outcome of the Fontan circulation appears to be adversely affected by altitude.
Data assessing the effect of altitude on Fontan haemodynamics are limited to experimental models and case reports. Both suggest a detrimental impact. This study describes exercise performance in patients with Fontan circulation and matched controls at a low altitude versus at sea level. We sought to assess the impact of increasing altitude on functional capacity in patients with Fontan palliation.
A retrospective review of 22 patients at low altitude (1602 metres) and 119 patients at sea level with Fontan circulation, as well as age-, gender-, and altitude-matched controls, underwent maximal cardiopulmonary exercise testing. Linear regression models were created to determine the influence of altitude on differences in exercise variables between Fontan patients and their matched controls.
Peak oxygen consumption was 28.4 millilitres per kilogram per minute (72% predicted) for the sea-level cohort and 24.2 millilitres per kilogram per minute (63% predicted) for the moderate altitude cohort. The matched case–control differences for patients at moderate altitude were greater for peak oxygen consumption (−29% against −13%, p = 0.04), anaerobic threshold (−36% against −5%, p = 0.001), and oxygen pulse (−35% against −18%, p = 0.007) when compared with patients living at sea level. When compared to institution-matched controls, the same parameters fell by 3%, 8.9%, and 4.2%, respectively, for each increase of 1000 feet in residential altitude (p = 0.03, p = 0.001, and p = 0.05, respectively).
Patients with Fontan circulation at a higher altitude have impairment in aerobic capacity when compared with patients at sea level. Reduction in exercise capacity is associated with a reduction in stroke volume, likely related to increased pulmonary vascular resistance.
Elevation; oxygen consumption; anaerobic threshold
We ranked the haemodynamics and pulmonary artery (PA) configurations of Norwood with bidirectional Glenn shunt (NW-G) patients among the other staged Fontan completion (conventional) patients in this study.
Between August 2001 and April 2010, 91 consecutive patients completed staged Fontan operations. Among them, NW-G was performed in 11.
There was no operative or late death except in one case which resulted from a reoperation after Fontan completion. Although the age at bidirectional Glenn (BDG) and Fontan completion was younger in NW-G (4.2 vs. 10.9 months, P < 0.01, and 2.3 vs. 3.3 years, P < 0.01), the interval between BDG and Fontan completion was not significantly different in these groups (23.6 vs. 28.0 months, P = 0.71). On Fontan completion, the extracardiac conduit size was significantly different (16.4 vs. 17.7 mm, P < 0.01). However, the pulmonary artery size (PA index) and the PA pressure were not significantly different (165.4 vs. 205.1 mm2/m2, P = 0.23, and 13.4 vs. 11.0 mmHg, P = 0.08). Particularly in hypoplastic left heart syndrome patients, the PA index was not significantly different between these groups (165.4 vs. 174.9 mm2/m2, P = 0.59).
The NW-G patients could have a subsequent Fontan completion with good results. There was no significant difference with respect to Fontan completion.
Norwood with bidirectional Glenn shunt; Staged Fontan operation; Haemodynamics; Pulmonary artery configuration
Rationale: Despite the recognition that acute lung injury (ALI) can elevate pulmonary artery (PA) pressure and right ventricular afterload, the impact of pulmonary vascular dysfunction on outcomes of these patients is not well defined.
Objectives: To investigate the impact of pulmonary vascular dysfunction in patients with acute lung injury.
Methods: Secondary analysis of the Fluid and Catheter Treatment Trial. A total of 501 patients who received a PA catheter were evaluated for associations between increases in transpulmonary gradient (TPG) (PA mean pressure − PA occlusion pressure) or pulmonary vascular resistance index (PVRi) and 60-day mortality, ventilator-, intensive care unit (ICU)–, and cardiovascular-free days (days with mean arterial pressure ≥ 60 mm Hg off vasopressor support).
Measurements and Main Results: We were able to measure the TPG in 475 (95%) and the PVRi in 470 (92%) patients. Patients with an elevated baseline TPG had an increased 60-day mortality (30 versus 19%; P = 0.02), and lower numbers of median ventilator- [25–75% quartiles] (15 [0–22] versus 19 [7–24]; P = 0.005), ICU- (14 [0–21] versus 18 [5–22]; P = 0.005), and cardiovascular-free days (23 [12–27] versus 25 [18–27]; P = 0.03). The median PVRi (305 [204–431] dyne s/cm5/m2) was elevated early in the course of ALI. PVRi was statistically higher in patients who died (326 [209–518] versus 299 [199–416]; P = 0.01). In individual multivariate models, TPG and PVRi remained independent risk factors for 60-day mortality and decrease in the number of ventilator-, ICU-, and cardiovascular-free days.
Conclusions: Pulmonary vascular dysfunction is common in ALI, and is independently associated with poor outcomes. Future trials targeting pulmonary vascular dysfunction may be indicated.
acute lung injury; pulmonary vasculature
Prompt diagnosis of candidaemia and invasive candidosis is crucial to the early initiation of antifungal therapy. The poor sensitivity of blood cultures (BCs) has led to the development of fungal glycan tests as a diagnostic adjunct. We analysed the performance of tests for the detection of circulating β-D-1,3-glucan (BDG) and mannan in the intensive care unit (ICU) setting.
This retrospective, case–control study included 43 ICU patients with candidaemia and 67 controls, hospitalised on the same ward and assessed weekly for yeast colonisation with simultaneous serum sampling; 340 sera taken before and after positive BCs were available for the cases group and 203 for the controls. BDG and mannan levels were determined using the Fungitell® and Platelia™ Candida Ag tests, respectively.
BDG was detected early in sera from cases patients but was also present in several sera from controls. Increasing the cut-off from 80 pg/mL to 350 pg/mL and 800 pg/mL resulted in sensitivity/specificity ratios of 0.97/0.31, 0.65/0.74, 0.30/0.86, respectively. Detection of mannan was more specific but lacked sensitivity. No obvious correlation was found between BDG and colonisation, but a trend existed between high colonisation and high BDG. Candidaemia relapses were associated with a rise in BDG and mannan but, in contrast to the transient nature of mannan, BDG persisted up to 7 weeks after positive BCs.
A combination of mannan and BDG tests could be used to guide pre-emptive therapeutic decisions in ICU patients.
OBJECTIVE—To compare the relative merits of cavopulmonary or aortopulmonary shunts, or both, as definitive non-Fontan palliations for patients with single ventricle physiology.
DESIGN—Clinical data, ECG, echocardiographic data, surgical records, and available postmortem material were reviewed in all patients with single ventricle physiology identified from the University of Toronto Congenital Cardiac Centre for Adults (UTCCCA) database who had not undergone a Fontan operation. Current status of patients was assessed from clinic reviews and patient contact. Two groups of patients were identified: those with cavopulmonary shunt (group 1, n = 35); and those with aortopulmonary shunt(s) only (group 2, n = 15).
RESULTS—50 adults (21 male/29 female) who underwent the last palliation at a median age of 11 years (range 1 day to 53 years) were identified. During a mean (SD) follow up of 13.0 (6.2) years at the UTCCCA, 19 patients died. Survival is 89.4% and 51.9% at 10 and 20 years, respectively, from the time patients were first seen at UTCCCA, with no differences between the groups. Most recent New York Heart Association (NYHA) classification was I-II in 21 patients, III in 25, and IV in four patients; mean haemoglobin was 190 (28) g/l, and oxygen saturation was 82 (4)%, with no group differences. Arrhythmia developed in 25 patients (atrial flutter/fibrillation in 20 and/or sustained ventricular tachycardia in 11). Atrial flutter/fibrillation was more common in patients in group 2, who also showed a greater decline in ventricular function with time. Age at last palliation, cardiothoracic ratio, and inclusion in group 2 were predictive of atrial flutter/fibrillation, poor ventricular function predictive of ventricular tachycardia, NYHA class > III, and prior ventricular tachycardia predictive of death.
CONCLUSIONS—Cavopulmonary or aortopulmonary shunts, or both, provide sustained palliation for selected patients with single ventricle physiology. Survival for both compares favourably with published Fontan series. Compared to aortopulmonary shunts, cavopulmonary shunts convey a beneficial long term effect on ventricular function. Arrhythmia is a major cause of late morbidity in these patients, relating to both ventricular dysfunction and death. Onset of sustained ventricular tachycardia is an ominous sign.
Keywords: congenital heart defects; cavopulmonary shunt; cyanosis; Fontan procedure
Ventricle‐pulmonary artery connections in patients after the Fontan procedure lead to ineffective volume loading and can cause long term problems. In patients with a cavopulmonary shunt anterograde pulmonary blood flow is frequently maintained, but can cause significant volume loading of the heart or complicate the subsequent Fontan procedure.
To evaluate the use of transcatheter closure of a ventricle‐pulmonary artery communication in the setting of a cavopulmonary shunt or after the Fontan procedure.
Patients and methods
Retrospective study at a tertiary referral centre. Eight patients (age 1.5–18 years, mean 7.8 years). Indications: cardiac failure or persistent pleural effusions after cavopulmonary shunt (n = 2) or after Fontan (n = 3) and abolishing the volume load of the single ventricle prior to Fontan completion (n = 3).
Devices used: Rashkind Umbrella (n = 1), Amplatzer PDA (n = 7) and Amplatzer ASD (n = 1). One patient required two devices. There were no procedural complications. All 3 patients with prolonged pleural effusions (1 post CP shunt and 2 post Fontan) showed complete resolution between 4 and 10 days after catheter closure. Two patients underwent transcatheter occlusion for progressive ventricular dilatation and cardiac failure. The first patient was post Fontan and showed gradual improvement in ventricular function. The second patient (post CP shunt) was in end stage cardiac failure due to severe AV valve regurgitation. The patient died 48 hours after an uncomplicated procedure due to ventricular failure and electromechanical dissociation (non‐procedure‐related cardiac death). Three patients underwent catheter closure to off‐load the systemic ventricle prior to the Fontan procedure. The device had to be removed prior to release in one patient, due to unsatisfactory position.
Transcatheter closure of ventricle‐pulmonary artery communication is a safe and effective technique in the treatment of selected patients after cavopulmonary shunt or Fontan procedure with early or late complications due to inappropriate pulmonary blood flow. This intervention should also be considered in the preparation for the Fontan procedure in selected patients with ventricular overload.
The Fontan circulation results from routing of the systemic venous blood to the pulmonary circulation without a hydraulic source of a ventricle. Although a hypertrophied right atrium was thought to be essential for this circulation, the current form of the operation has neither the right atrium nor any valves in the venous circulation that is connected to the pulmonary arteries directly. Modifications in the operative model was one of the early steps in improving outcome. Use of fenestration, staging of Fontan completion and better perioperative management have led to a significant drop in mortality rates in the current era. Despite this, there is late attrition of patients with complications such as arrhythmias, ventricular dysfunction, and unusual clinical syndromes of protein-losing enteropathy (PLE) and plastic bronchitis. Management of failing Fontan includes a detailed hemodynamic and imaging assessment to treat any correctable lesions such as obstruction within the Fontan circuit, early control of arrhythmia and maintenance of sinus rhythm, symptomatic treatment for PLE and plastic bronchitis, manipulation of systemic and pulmonary vascular resistance, and Fontan conversion of less favorable atriopulmonary connection to extra-cardiac total cavopulmonary connection with arrythmia surgery. Cardiac transplantation remains the only successful definitive palliation in the failing Fontan patients.
Failing Fontan; protein losing enteropathy; cardiac transplantation
Pulmonary arteriovenous malformations (PAVMs) are a common source of morbidity after bidirectional superior cavopulmonary anastomosis (Glenn). The diversion of hepatic venous effluent away from the pulmonary circulation after Glenn appears to play a significant role in the pathogenesis of PAVMs. Although the liver is known to produce factors that regulate vascular development, specific hepatic inhibitors of angiogenesis have not been described in the post-Glenn population. Endostatin, produced from its precursor collagen XVIII, is a potent inhibitor of angiogenesis produced by the liver. This study aimed to investigate the hypothesis that endostatin levels decrease in patients after Glenn. Levels of endostatin and its precursor, long-type collagen XVIII, were determined by enzyme-linked immunoassay and immunoprecipitation, respectively, for serum samples from 38 patients undergoing Glenn, total cavopulmonary anastomosis (Fontan), or biventricular repair of cardiac defects. Samples were obtained before surgery and 24 h afterward. In patients undergoing a bidirectional Glenn procedure, endostatin levels decreased after surgery (n = 17; 4.42 vs 3.34 ng/ml; p < 0.001), and long type-collagen XVIII levels increased by 200 % (n = 10; p = 0.0001). However, endostatin levels did not change after surgery in patients undergoing Fontan (n = 13) or biventricular repair (n = 8). In patients undergoing Fontan, long-type collagen XVIII increased by 18 % (p < 0.01), whereas in control subjects, the levels were unchanged. These data suggest that the diversion of hepatic blood flow away from the pulmonary circulation in patients after the Glenn procedure inhibits endostatin production from collagen XVIII, resulting in decreased circulating serum endostatin levels. A decrease in endostatin may promote angiogenesis. The mechanism whereby the pulmonary circulation processes endostatin and its potential role in the pathogenesis of PAVMs warrant further study.
Angiogenesis inhibitor; Cardiac repair; Collagen XVIII; Congenital heart disease; Endostatin; Pulmonary arteriovenous malformations
Systemic to pulmonary collateral flow (SPCF) is common in single ventricle patients (pts) with superior cavopulmonary connections (BDG). Because no validated method to quantify SPCF exists, neither its hemodynamic burden nor clinical impact can be systematically evaluated. We hypothesize that (1) the difference in total ascending aortic (Ao) and caval flow (SVC+IVC) and (2) the difference between pulmonary vein and artery flow (PV − PA) provide two independent estimators of SPCF.
Methods and Results
We measured Ao, SVC, IVC, right (RPA) and left (LPA) PA, left (LPV), and right (RPV) PV flows in 17 BDG pts during routine cardiac magnetic resonance imaging studies using through-plane phase contrast velocity mapping. Two independent measures of SPCF were obtained: (1) Ao − (SVC + IVC). (2) (LPV−LPA) + (RPV−RPA). Values were normalized to body surface area (BSA), Ao, and PV and comparisons made using linear regression and Bland-Altman analysis. SPCF ranged from 0.2–1.4 L/min for (1) and 0.2–1.6 L/min for (2) for an average indexed SPCF of 0.5–2.8 L/min/m2 : 11–53% (mean 37%) of Ao and 19–77% (mean 54%) of PV. The mean difference between (1) and (2) was 0.01 L/min (p=0.40, 2 S.D. range −0.45–0.47 L/min).
We present a noninvasive method for the SPCF quantification in pts with BDG. It should provide an important clinical tool in managing these patients. Furthermore, we show that SPCF is a significant hemodynamic burden in many patients with BDG physiology. Future investigations will allow objective study of the impact of collateral flow on outcome.
single ventricle; collateral circulation; magnetic resonance imaging; blood flow; superior cavopulmonary connection
To explore the clinical value of low-dose prospectively electrocardiogram-gated axial dual-source CT angiography (low-dose PGA scanning, CTA) in patients with pulsatile bilateral bidirectional Glenn shunt (bBDG) as an alternative noninvasive method for postoperative morphological estimation.
Twenty patients with pulsatile bBDG (mean age 4.2±1.6 years) underwent both low-dose PGA scanning and conventional cardiac angiography (CCA) for the morphological changes. The morphological evaluation included the anatomy of superior vena cava (SVC) and pulmonary artery (PA), the anastomotic location, thrombosis, aorto-pulmonary collateral circulation, pulmonary arteriovenous malformations, etc. Objective and subjective image quality was assessed. Bland–Altman analysis and linear regression analyses were used to evaluate the correlation on measurements between CTA and CCA. Effective radiation dose of both modalities was calculated.
The CT attenuation value of bilateral SVC and PA was higher than 300 HU. The average subjective image quality score was 4.05±0.69. The morphology of bilateral SVC and PA was displayed completely and intuitively by CTA images. There were 24 SVC above PA and 15 SVC beside PA. Thrombosis was found in 1 patient. Collateral vessels were detected in 13 patients. No pulmonary arteriovenous malformation was found in our study. A strong correlation (R2>0.8, P<0.001) was observed between the measurements on CTA images and on CCA images. Bland–Altman analysis demonstrated a systematic overestimation of the measurements by CTA (the mean value of bias>0).The mean effective dose of CTA and CCA was 0.50±0.17 mSv and 4.85±1.34 mSv respectively.
CT angiography with a low-dose PGA scanning is an accurate and reliable noninvasive examination in the assessment of morphological changes in patients with pulsatile bBDG.
Parallel advancements in surgical technique, preoperative and postoperative care, as well as a better understanding of physiology in patients with duct-dependent pulmonary or systemic circulation and a functional single ventricle, have led to superb results in staged palliation of most complex congenital heart disease (CHD) . The Fontan procedure and its technical modifications have resulted in markedly improved outcomes of patients with single ventricle anatomy [2,3,4]. The improved early survival has led to an exponential increase of the proportion of Fontan patients surviving long into adolescence and young adulthood . Improved early and late survival has not yet abolished late mortality secondary to myocardial failure, therefore increasing the referrals for cardiac transplantation . Interstage attrition  is moreover expected in staged palliation towards completion of a Fontan-type circulation, while Fontan failure represents a growing indication for heart transplantation . Heart transplantation has therefore become the potential “fourth stage”  or a possible alternative to a high-risk Fontan operation  in a strategy of staged palliation for single ventricle physiology. Heart transplant barely accounts for 16% of pediatric solid organ transplants . The thirteenth official pediatric heart transplantation report- 2010  indicates that pediatric recipients received only 12.5% of the total reported heart transplants worldwide. Congenital heart disease is not only the most common recipient diagnosis, but also the most powerful predictor of 1-year mortality after OHT. Results of orthotopic heart transplantations (OHT) for failing single ventricle physiology are mixed. Some authors advocate excellent early and mid-term survival after OHT for failing Fontan , while others suggest that rescue-OHT after failing Fontan seems unwarranted . Moreover, OHT outcome appears to be different according to the surgical staging towards the Fontan operation and surgical technique of Fontan completion .
The focus of this report is a complete review of the recent literature on OHT for failing single ventricles, outlining the clinical issues affecting Fontan failure, OHT listing and OHT outcome. These data are endorsed reporting our experience with OHT for failing single ventricle physiology in recent years.
Pediatric heart transplantation; fontan failure; univertricular physiology.
This study sought to investigate changes in magnetic resonance imaging (MRI) ventricular volumes and vascular dimensions before hemi-Fontan (HF) and before total cavopulmonary connection (TCPC) in children with hypoplastic left heart syndrome (HLHS).
The systemic right ventricle (RV) in HLHS is subject to significant changes in volume loading throughout the surgical stages of palliation, particularly after the HF.
Fifty-eight patients had paired pre-HF and pre-TCPC MRI for assessment of changes of RV volumes, neoaortic flow, and vascular dimensions.
Comparison of pre-HF and pre-TCPC MRI results showed a decrease of indexed RV end-diastolic volume and end-systolic volume (98 ml/m2 to 87 ml/m2 and 50 ml/m2 to 36 ml/m2, respectively) with stroke volume remaining constant (49 ml/m2 vs. 51 ml/m2), leading to an increased RV ejection fraction (51% vs. 59%). These findings persisted after excluding the 3 patients who underwent tricuspid valve repair as part of their HF procedure. Indexed RV end-diastolic volume plotted against neoaortic stroke volume demonstrated a Frank-Starling–like curve that shifted upward after HF. The indexed distal left and right cross-sectional pulmonary artery areas were reduced after HF.
In HLHS, serial MRI shows the adaptation of the systemic RV after HF with volume reduction in the context of a preserved stroke volume and an increased ejection fraction. The staged palliation in HLHS may be a risk factor particularly for reduced left pulmonary artery growth in itself as no factors investigated in this study were found to significantly impact on this.
hemi-Fontan operation; hypoplastic left heart syndrome; magnetic resonance imaging; Norwood procedure; remodeling of systemic right ventricle; 3D, 3-dimensional; EDV, end-diastolic volume; EF, ejection fraction; ESV, end-systolic volume; HF, hemi-Fontan; HLHS, hypoplastic left heart syndrome; HR, heart rate; iEDV, indexed end-diastolic volume; iESV, indexed end-systolic volume; iSV, indexed stroke volume; LPA, left pulmonary artery; LV, left ventricle; MRI, magnetic resonance imaging; RPA, right pulmonary artery; RV, right ventricle; SENSE, sensitivity encoding; SSFP, steady-state free precession; TCPC, total cavopulmonary connection; TR, tricuspid regurgitation
OBJECTIVE—To determine whether patients with cavopulmonary connection have higher levels of vasoactive/water-salt regulating hormones and if so, whether hormone levels are related to postoperative haemodynamics and postoperative follow up.
DESIGN—Cross sectional study.
PATIENTS—20 patients (New York Heart Association functional class I-II), mean age 11 years (range 4 to 22), were studied at a mean of 2 years (0.5 to 6) after a total cavopulmonary connection (TCPC, n = 12) or a bidirectional Glenn anastomosis (BDG, n = 8).
INTERVENTIONS—Cardiac catheterisation was performed and blood samples were drawn. Control blood samples were drawn from 33 healthy children, mean age 12 years (6 to 16).
MAIN OUTCOME MEASURES—Plasma levels of angiotensin II, renin, aldosterone, arginine, vasopressin, atrial natriuretic factor (ANF), brain natriuretic peptide (BNP).
RESULTS—All neurohormones were significantly increased in both TCPC and BDG patients (p < 0.05), with a fourfold increase in angiotensin II, renin, and aldosterone, and a twofold increase in vasopressin, ANF, and BNP (compared with healthy controls). There was no correlation between haemodynamic variables and hormone levels. Angiotensin II and renin were inversely correlated with time to follow up. All subjects over 15 years (n = 5) had normal neurohormonal levels.
CONCLUSIONS—Neurohormones were raised for years after successful cavopulmonary operations but lower levels were observed with time on follow up. This supports the hypothesis that neurohormonal activation is primarily related to altered postoperative physiology and that adaptation takes place over time.
Keywords: neurohormones; cavopulmonary connection; congenital heart disease; paediatric cardiology
To evaluate the outcome of pregnancy in women after Fontan palliation and to assess the occurrence of infertility and menstrual cycle disorders.
Design and patients
Two congenital heart disease registries were used to investigate 38 female patients who had undergone Fontan palliation (aged 18–45 years): atriopulmonary anastomosis (n = 23), atrioventricular connection (n = 5) and total cavopulmonary connection (n = 10).
Six women had 10 pregnancies, including five miscarriages (50%) and one aborted ectopic pregnancy. During the remaining four live‐birth pregnancies clinically significant complications were encountered: New York Heart Association class deterioration; atrial fibrillation; gestational hypertension; premature rupture of membranes; premature delivery; fetal growth retardation and neonatal death. Four of seven women who had attempted to become pregnant reported female infertility: non‐specified secondary infertility (n = 2), uterus bicornis (n = 1) and related to endometriosis (n = 1). Moreover, several important menstrual cycle disorders were documented. In particular, the incidence of primary amenorrhoea was high (n = 15, 40%), which resulted in a significant increase in age at menarche (14.6 (SD 2.1) years, p < 0.0001, compared with the general population).
Women can successfully complete pregnancy after adequate Fontan palliation without important long‐term sequelae, although it is often complicated by clinically significant (non‐)cardiac events. In addition, subfertility or infertility and menstrual disorders were common.
A superior cavopulmonary connection is commonly performed before the Fontan procedure in patients with a functionally univentricular heart. Data are limited regarding associations between a prior superior cavopulmonary connection and functional and ventricular performance late after the Fontan procedure.
We compared characteristics of those with and without prior superior cavopulmonary connection among 546 subjects enrolled in the Pediatric Heart Network Fontan Cross-Sectional Study. We further compared different superior cavopulmonary connection techniques: bidirectional cavopulmonary anastomosis (n equals 229), bilateral bidirectional cavopulmonary anastomosis (n equals 39), and hemi-Fontan (n equals 114).
A prior superior cavopulmonary connection was performed in 408 subjects (75%); the proportion differed by year of Fontan surgery and centre (p-value less than 0.0001 for each). The average age at Fontan was similar, 3.5 years in those with superior cavopulmonary connection versus 3.2 years in those without (p-value equals 0.4). The type of superior cavopulmonary connection varied by site (p-value less than 0.001) and was related to the type of Fontan procedure. Exercise performance, echocardiographic variables, and predominant rhythm did not differ by superior cavopulmonary connection status or among superior cavopulmonary connection types. Using a test of interaction, findings did not vary according to an underlying diagnosis of hypoplastic left heart syndrome.
After controlling for subject and era factors, most long-term outcomes in subjects with a prior superior cavopulmonary connection did not differ substantially from those without this procedure. The type of superior cavopulmonary connection varied significantly by centre, but late outcomes were similar.
Congenital heart disease; Fontan; functionally univentricular heart; quality of life
In a univentricular Fontan circulation, modest augmentation of existing cavopulmonary pressure head (2–5 mmHg) would reduce systemic venous pressure, increase ventricular filling, and thus, substantially improve circulatory status. An ideal means of providing mechanical cavopulmonary support does not exist. We hypothesized that a viscous impeller pump, based on the von Kármán viscous pump principle, is optimal for this role.
A 3-dimensional computational model of the total cavopulmonary connection was created. The impeller was represented as a smooth 2-sided conical actuator disk with rotation in the vena caval axis. Flow was modeled under 3 conditions: 1) passive flow with no disc; 2) passive flow with a non-rotating disk, and 3) induced flow with disc rotation (0–5K rpm). Flow patterns and hydraulic performance were examined for each case. Hydraulic performance for a vaned impeller was assessed by measuring pressure rise and induced flow over 0–7K rpm in a laboratory mock loop.
A nonrotating actuator disc stabilizes cavopulmonary flow, reducing power loss by 88%. Disk rotation (from baseline dynamic flow of 4.4 L/min) resulted in a pressure rise of 0.03 mmHg. A further increase of pressure of 5–20 mmHg and 0–5 L/min flow were obtained with a vaned impeller at 0–7K rpm in a laboratory mock loop.
A single viscous impeller pump stabilizes and augments cavopulmonary flow in 4 directions, in the desired pressure range, without venous pathway obstruction. It applies to the existing staged protocol as a temporary bridge-to-recovery or –transplant in established univentricular Fontan circulations. It may also enable compressed palliation of single ventricle without need for intermediary surgical staging or use of a systemic-to-pulmonary arterial shunt.
A male infant with the rare lesion of unguarded tricuspid orifice in the setting of pulmonary valve atresia, intact ventricular septum, and a hypoplastic right ventricle is described. The patient presented with cyanosis at 1 day old; transcutaneous oxygen saturations were between 20% and 30% in room air, and 60% in 100% inspired oxygen. Pre-excitation was found incidentally on the ECG and the potential for rapid antegrade conduction of atrial tachyarrhythmias, after eventual extended palliation with the Fontan procedure, was demonstrated at electrophysiological study. By 11 months old the patient was becoming increasingly cyanosed and interim palliation with a bidirectional cavopulmonary shunt was proposed. Successful radiofrequency ablation of the accessory pathway was performed before bidirectional cavopulmonary shunt, which would have prevented access to the heart via the superior vena cava. Difficulty with femoral venous access because of previous occlusion of a femoral vein was overcome by the use of 2 F pacing electrodes and a 5 F ablation catheter.
Keywords: radiofrequency ablation; accessory pathway; unguarded tricuspid orifice
Persistent left superior vena cava (SVC) is a not uncommon finding in patients with congenital heart disease. This anatomical variant must be recognised before doing a Glenn anastomosis, bidirectional cavopulmonary connection or a Fontan-type procedure. Following these procedures, reopening of a left SVC leading to clinical cyanosis can occur. Five cases are described in whom persisting left SVCs were excluded before performing a bidirectional cavopulmonary connection or Fontan procedure but (re-)opened after surgery, leading to cyanosis either by reducing effective pulmonary blood flow (bidirectional cavopulmonary connection) or by an obligatory right to left shunt (Fontan). These observations suggest that, embryologically, the lumen of the left SVC obliterates rather than disappears. Balloon occlusion angiography of the innominate vein before cavopulmonary connections or Fontan procedures might improve detection of these collateral vessels.
Keywords: persistent left superior vena cava; cavopulmonary connection; Fontan procedure; congenital heart disease
The clinical benefits of the Fontan operation in treating single-ventricle defects have been well documented. However, perioperative mortality or morbidity remains a critical problem. The purpose of the present study was to identify the cardiovascular factors that dominate the transient hemodynamic changes upon the change of a bidirectional cavopulmonary (Glenn) anastomosis (BCPA) into a total cavopulmonary connection (TCPC). For this purpose, two computational models were constructed to represent, respectively, a single-ventricle circulation with a BCPA and that with a TCPC. A series of model-based simulations were carried out to quantify the perioperative hemodynamic changes under various cardiovascular conditions. Obtained results indicated that the presence of a low pulmonary vascular resistance and/or a low lower-body vascular resistance is beneficial to the increase in transpulmonary flow upon the BCPA to TCPC change. Moreover, it was found that ventricular diastolic dysfunction and mitral valve regurgitation, despite being well-known risk factors for poor postoperative outcomes, do not cause a considerable perioperative reduction in transpulmonary flow. The findings may help physicians to assess the perioperative risk of the TCPC surgery based on preoperative measurement of cardiovascular function.
Background and Objectives
Recent surgical results from total anomalous pulmonary venous return (TAPVR) are reported to have improved; however, mortality and morbidity are still high in the univentricles. This review was performed in order to demonstrate surgical results from TAPVR for recent years in a single institute.
Subjects and Methods
A total of 53 patients with TAPVR underwent surgery between January 2000 and December 2008. Preoperative anatomy and hemodynamics were evaluated by 2-dimensional echocardiogram. We reviewed medical records on preoperative management, age, and body weight at time of surgery, postoperative mortality, and pulmonary venous obstruction.
The study included 36 biventricle patients and 17 univentricle patients. Median age and weight at time of surgery were 26 days and 3.5 kg, respectively. During the mean follow up period of 48.2 months, a total of 11 deaths and 8 early deaths occurred. Postoperative pulmonary venous stenosis occurred in 8 patients. Among 36 biventricle patients, mortality occurred in 1 patient and postoperative pulmonary venous stenosis occurred in 6 patients. No statistical significances were observed between postoperative pulmonary venous stenosis and other factors. Among 17 univentricule patients, mortality was 10, including 7 early deaths, and postoperative pulmonary venous stenosis occurred in 2 patients. Combined palliations were modified Blalock-Taussig (BT) shunts in 7, pulmonary artery banding (PAB) in 3, bidirectional cavopulmonary shunt in 5, and the Fontan procedure in 1. The highest mortality was recorded in patients with a modified BT shunt (85.7%) and next in patients with PAB (66.6%). Mortality was not related to anatomy of TAPVR, nor preoperative obstruction, but with significant age and weight at time of surgery.
Despite improvement in operative results from TAPVR, surgery in univentricles is highly risky, especially with low weight and early age, with concomitant palliation.
Pulmonary vein; Anomaly; Univentricular heart
Extra-cardiac conduit (ECC) and Lateral atrial tunnel (LAT) total cavopulmonary connection are both widely used in management of functionally univentricular hearts. The impact of the type of connection on early outcomes after Fontan operation remains unclear. We evaluated the impact of Fontan type on early outcome in a large clinical database.
Patients in the Society of Thoracic Surgeons Congenital Heart Surgery Database undergoing the Fontan operation (2000–2009) were included. In multivariable analysis, we evaluated the impact of Fontan type (ECC vs. LAT) on in-hospital mortality, Fontan takedown/revision, Fontan failure (in-hospital mortality or Fontan takedown/revision), post-operative length of stay (LOS), and complications, adjusting for patient, procedural, and center factors.
A total of 2747 patients from 68 centers were included: 61% were male and 45% had a right dominant ventricle. ECC Fontan (vs. LAT) was performed in 63%; in all 65% were fenestrated. In multivariable analysis with adjustment for patient, procedural (including fenestration), and center factors (including Fontan volume), ECC Fontan was associated with significantly higher Fontan takedown/revision (OR 2.73, 95%CI 1.09–6.87) and Fontan failure (OR 2.28, 95%CI 1.13–4.59), and longer post-operative length of stay (adjusted estimated difference in LOS: +1.4 days).
These multicenter data suggest that of the two prevalent forms of Fontan connection in current use, the LAT Fontan may be associated with superior early outcomes.
Congenital Heart Disease; Outcomes; Fontan