Impact of veno-venous collaterals on outcome after the total cavopulmonary connection.

OBJECTIVE: To evaluate the prevalence of veno-venous collaterals (VVCs) after total cavopulmonary connection (TCPC) and analyze their impact on outcomes. METHODS: Patients undergoing TCPC between 1994 and 2022 were evaluated. VVCs were identified using angiograms of cardiac catheterizations and their impact on outcomes was analyzed. RESULTS: A total of 635 patients were included. Median age at TCPC was 2.3 (interquartile ranges (IQR): 1.8-3.3) years. The most frequent diagnosis was hypoplastic left heart syndrome in 173 (27.2%) patients. Prior bidirectional cavopulmonary shunt was performed in 586 (92.3%) patients at a median age of 5.3 (3.6-9.9) months. VVCs were found in 94 (14.8%) patients at a median of 2.8 (0.1-11.8) years postoperatively. The prevalence of VVCs was similar between the dominant right and left ventricle (14.7 vs. 14.9%, p = 0.967). Mean pulmonary artery pressure (16.2 vs. 16.0 mmHg, p = 0.902), left atrial pressure (5.5 vs. 5.7 mmHg, p = 0.480), transpulmonary gradient (4.0 vs. 3.8 mmHg, p = 0.554) and oxygen saturation (81.4 vs. 82.6%, p = 0.103) before TCPC were similar between patients with and without VVCs. The development of VVCs did not affect survival after TCPC (p = 0.161). Nevertheless, VVCs were a risk for the development of plastic bronchitis (PB, p < 0.001). Interventional closure of VVCs was performed in 60 (9.4%) patients at a median of 8.9 (0.6-15.1) years after TCPC, and improvement of oxygen saturation was observed in 66% of the patients. CONCLUSIONS: The prevalence of VVCs after TCPC was 15%. VVCs had no impact on survival following TCPC but were associated with a high prevalence of PB.

Common arterial trunk in functionally univentricular hearts: a case series.

INTRODUCTION: The association of a univentricular heart defect with common arterial trunk is extremely rare. There is a lack of population-based outcome studies reported in the literature. METHODS: The hospital records, echocardiographic and other imaging modality data, outpatients' records, operation notes, and other electronic data were reviewed. Patients were reviewed, and the final outcomes of surgery were observed. RESULTS: Six cases (two males) with common arterial trunk presented over a 30-year period. Five had a complete unbalanced atrioventricular septal defect (83%) and one (17%) had tricuspid atresia associated with common arterial trunk. All had antenatal diagnosis. Two cases (33%) were excluded from initial surgical palliation due to Trisomy 21 in one and severe truncal valve regurgitation in one. Initial surgical palliation was performed in four cases (67%) at median age of 31 days (2-60) and consisted of disconnection and reconstruction of the pulmonary arteries and establishing controlled pulmonary blood flow. There were no early deaths. Conversion to cavopulmonary shunt was not possible in two due to severe airway problems in one and pulmonary arteries anatomy in one. They died at 11 and 16 months, respectively. Two patients (33%) underwent cavopulmonary shunt with 1 (17%) being alive at 18 months - 12 months after cavopulmonary shunt. The second patient proceeded to Fontan completion at 19 months but required catheter takedown 3 months later and died 3.5 years later. CONCLUSIONS: Univentricular hearts with common arterial trunk carry extremely poor short- to medium-term outcomes. This should inform antenatal and postnatal counselling and decision-making.

Exercise capacity after total cavopulmonary anastomosis: a longitudinal paediatric and adult study.

AIMS: Fontan palliation is a surgical strategy for patients with complex congenital heart disease, in whom biventricular circulation cannot be achieved. Long-term survival is negatively affected by the absence of sub-pulmonary ventricle and increased systemic venous pressure. Exercise capacity is a known predictor of overall survival and quality of life in congenital heart defects. We aim to track individual trends of peak oxygen uptake (V̇O2 peak) after total cavopulmonary connection (TCPC), identify predictors of deterioration, and derive a disease-specific reference V̇O2 peak dataset. METHODS AND RESULTS: A retrospective study of serial cardiopulmonary exercise testing (CPET) data, gathered from all patients who underwent TCPC in the Czech Republic between 1992 and 2016. Of 354 consecutive patients with TCPC, 288 (81.4%) patients underwent one or more CPETs yielding 786 unique V̇O2 peak values used as a reference dataset. Longitudinal data were available in 206 (58.2%) patients, who underwent a median (inter-quartile range) of 3.0 (2.0-5.0) CPETs over a mean (standard deviation) of 8.9 (5.5) years. The decline of exercise capacity with age was linear and not faster than in healthy peers (P = 0.47), but relative values of V̇O2 peak in TCPC patients were 12.6 mL/min/kg lower. Single ventricular morphology and pulmonary artery size had no significant influence on the exercise capacity dynamics. V̇O2 peak decline correlated negatively with the trend of body mass index z-score (P = 0.006) and was faster in women than men (P = 0.008). CONCLUSIONS: Total cavopulmonary connection patients have significantly reduced exercise capacity. The age-related decline paralleled the healthy population and correlated negatively with the body mass index trend. The presented V̇O2 peak reference dataset may help the clinicians to grade the severity of exercise capacity impairment in individual TCPC patients.

Purpose-Built Transcatheter Cavopulmonary Anastomosis Device Requirements: Multi-Modality Imaging Evaluation.

BACKGROUND/PURPOSE: Patients with a functional single ventricle undergo multiple, palliative open-heart surgeries. This includes a superior cavopulmonary anastomosis or bidirectional Glenn shunt. A less-invasive transcatheter approach may reduce morbidity. METHODS/MATERIALS: We analyzed pre-Glenn X-ray contrast angiography (XA), cardiac computed tomography (CT), and cardiac magnetic resonance (CMR) studies. RESULTS: Over an eleven-year period (1/2007 - 6/2017), 139 Glenn surgeries were performed at our institution. The typical age range at surgery was 59 - 371 days (median = 163; IQR = 138 - 203). Eight-nine XA, ten CT, and ten CMR studies obtained from these patients were analyzed. Cephalad SVC measurements (millimeters) were 7.3 ± 1.7 (XA), 7.7 ± 1.6 (CT) and 6.9 ± 1.8 (CMR). RPA measurements were 7.3 ± 1.9 (XA), 7.4 ± 1.6 (CT) and 6.6 ± 1.9 (CMR). Potential device lengths were 10.9 ± 6 - 17.4 ± 6.4 (XA), 10.1 ± 2.1 - 17.7 ± 2.4 (CT) and 17.3 ± 4. - 23.7 ± 5.5 (CMR). SVC-RPA angle (degrees) was 132.9 ± 13.2 (CT) and 140 ± 10.2 (MRI). Image quality of all CT (100%), almost all XA (SVC 100%, RPA 99%), and most MRI (SVC 80%, RPA 90%) were deemed sufficient. Parametric modeling virtual fit device with 10 mm diameter and 20 - 25 mm length was ideal. CONCLUSIONS: Ideal transcatheter cavopulmonary shunt device for the typical patient would be 10 mm in diameter and 20-25 mm in length.

Surgical Timing and Outcomes of Unilateral Versus Bilateral Superior Cavopulmonary Anastomosis: An Analysis of Pediatric Heart Network Public Databases.

Requiring bilateral superior cavopulmonary anastomosis (bSCPA) instead of unilateral superior cavopulmonary anastomosis (uSCPA) could influence surgical timing and outcomes. We compared surgical timing and outcomes for patients who underwent uSCPA to those who underwent bSCPA through use of the Pediatric Heart Network's public datasets for the Infant Single Ventricle trial and Single Ventricle Reconstruction trial. There was no statistically significant difference in median age at SCPA (158 vs. 150 days, p = 0.68), hospital length of stay (LOS) (7 vs. 7 days, p = 0.74), intensive care unit (ICU) LOS (4 vs. 5 days, p = 0.53), time requiring ventilator support (2 vs. 2 days, p = 0.51), or oxygen saturation at discharge (82 vs. 81%, p = 0.22) between the uSCPA and bSCPA groups, respectively. However, sub-analysis comparing only those who underwent early SCPA, at < 120 days of age, revealed significantly longer hospital LOS (8 vs. 13 days, p = 0.04), ICU LOS (5 vs. 11 days, p = 0.01), and time requiring ventilator support (2 vs. 4 days, p = 0.03) for the early bSCPA group when compared to the early uSCPA group. A multivariable logistic regression revealed bSCPA to be the only significant predictor of prolonged hospital LOS for patients who underwent early SCPA (odds ratio 4.1, 95% CI 1.2-14.2). Overall, there was no difference in surgical timing or outcome measures between uSCPA and bSCPA. However, early bSCPA, performed at < 120 days, had worse outcome measures than early uSCPA. Delaying elective bSCPA until at least 120 days of age could minimize morbidity in infants with bilateral superior venae cavae.

Impact of the superior cavopulmonary anastomosis on cerebral oxygenation.

BACKGROUND: Patients with univentricular heart disease may undergo a superior cavopulmonary anastomosis, an operative intervention that raises cerebral venous pressure and impedance to cerebral venous return. The ability of infantile cerebral autoregulation to compensate for this is not well understood. MATERIALS AND METHODS: We identified all patients undergoing a superior cavopulmonary anastomosis (cases) and compared metrics of cerebral oxygenation upon admission to the ICU with patients following repair of tetralogy of Fallot or arterial switch operation (controls). The primary endpoint was cerebral venous oxyhaemoglobin saturation measured from an internal jugular venous catheter. Other predictor variables included case-control assignment, age, weight, sex, ischemic times, arterial oxyhaemoglobin saturation, mean arterial blood pressure, and superior caval pressure. RESULTS: A total of 151 cases and 350 controls were identified. The first post-operative cerebral venous oxyhaemoglobin saturation was significantly lower following superior cavopulmonary anastomosis than in controls (44 ± 12 versus 59 ± 15%, p < 0.001), as was arterial oxyhaemoglobin saturation (81 ± 9 versus 98 ± 5%, p < 0.001). Cerebral venous oxyhaemoglobin saturation correlated poorly with superior caval pressure in both groups. When estimated by linear mixed effects model, arterial oxyhaemoglobin saturation was the primary determinant of central venous oxyhaemoglobin saturation in both groups (ß = 0.79, p = 3 × 10-14); for every 1% point increase in arterial oxyhaemoglobin saturation, there was a 0.79% point increase in venous oxyhaemoglobin saturation. In this model, no other predictors were significant, including superior caval pressure and case-control assignment. CONCLUSION: Cerebral autoregulation appears to remain intact despite acute imposition of cerebral venous hypertension following superior cavopulmonary anastomosis. Following superior cavopulmonary anastomosis, cerebral venous oxyhaemoglobin saturation is primarily determined by arterial oxyhaemoglobin saturation.

A Tribute to the Pioneers of Right Heart Bypass: An Historical Review.

Cavopulmonary anastomosis was first described by Carlon, Mondini, De Marchi in a canine model in 1951 and later, in the clinical practice, by Glenn in 1958. Total right heart bypass was first introduced by Fontan and Kreutzer in 1971, in each instance as treatment for tricuspid atresia. Several modifications of such a procedure followed the initial concept of the right atrium as a pumping chamber, including modifications aimed to minimize energy loss at the anastomotic level and arrhythmias. Tribute is given to our pioneers who developed such an operation aimed to treat any child with functionally univentricular hearts.

Heart failure in single right ventricle congenital heart disease: physiological and molecular considerations.

Because of remarkable surgical and medical advances over the past several decades, there are growing numbers of infants and children living with single ventricle congenital heart disease (SV), where there is only one functional cardiac pumping chamber. Nevertheless, cardiac dysfunction (and ultimately heart failure) is a common complication in the SV population, and pharmacological heart failure therapies have largely been ineffective in mitigating the need for heart transplantation. Given that there are several inherent risk factors for ventricular dysfunction in the setting of SV in addition to probable differences in molecular adaptations to heart failure between children and adults, it is perhaps not surprising that extrapolated adult heart failure medications have had limited benefit in children with SV heart failure. Further investigations into the molecular mechanisms involved in pediatric SV heart failure may assist with risk stratification as well as development of targeted, efficacious therapies specific to this patient population. In this review, we present a brief overview of SV anatomy and physiology, with a focus on patients with a single morphological right ventricle requiring staged surgical palliation. Additionally, we discuss outcomes in the current era, risk factors associated with the progression to heart failure, present state of knowledge regarding molecular alterations in end-stage SV heart failure, and current therapeutic interventions. Potential avenues for improving SV outcomes, including identification of biomarkers of heart failure progression, implications of personalized medicine and stem cell-derived therapies, and applications of novel models of SV disease, are proposed as future directions.

Cavopulmonary Anastomosis in a Patient With Arrhythmogenic Right Ventricular Cardiomyopathy With Severe Right Ventricular Dysfunction.

A 26-year-old lady presented with exertional dyspnea, palpitations, central cyanosis, and oxygen saturations of 80% in room air. Her electrocardiogram, echocardiogram, and cardiac magnetic resonance were diagnostic of arrhythmogenic right ventricular dysplasia. There was no documented ventricular arrhythmia or syncopal episodes and Holter recordings were repeatedly normal. Cardiac hemodynamics showed right to left shunt through atrial septal defect, low pulmonary blood flow, normal atrial pressures, and minimally elevated right ventricular end-diastolic pressures. Since her presenting symptoms and cyanosis were attributed to reduced pulmonary blood flow, she underwent off-pump cavopulmonary anastomosis between right superior vena cava and right pulmonary artery. As we intended to avoid the adverse effect of extracorporeal circulation on the myocardial function and pulmonary vasculature, we did not attempt to reduce the size of the atrial septal defect. Her postoperative period was uneventful; oxygen saturation improved to 89% with significant improvement in effort tolerance. At 18-month follow-up, there were no ventricular arrhythmias on surveillance. The clinical presentation of this disease may vary from serious arrhythmias warranting defibrillators and electrical ablations at one end to right ventricular pump failure warranting cardiomyoplasty or right ventricular exclusion procedures at the other end. However, when the presentation was unusual with severe cyanosis through a stretched foramen ovale leading to reduced pulmonary blood flows, Glenn shunt served as a good palliation and should be considered as one of the options in such patients.

A Case Report of Reconstruction of the Left Superior Vena Cava Using the Right Superior Vena Cava Autograft at Bilateral Bidirectional Superior Cavopulmonary Anastomosis.

The choice of graft material for reconstruction of the vena cava in pediatric patients remains controversial. We successfully treated an eight-month-old female patient with single ventricle physiology and long segment obstruction of the left superior vena cava using the right superior vena cava autograft at the time of bilateral bidirectional superior cavopulmonary anastomosis. Postoperative computed tomography confirmed the patency of the reconstruction.

Predicting the pressure of the total cavopulmonary connection: clinical testing of a mathematical equation.

INTRODUCTION: Some authors advocate the use of a dedicated formula to predict the Fontan pressure starting from pre-Fontan catheterisation data. This paper aims at testing the predictive value of the mentioned formula through a retrospective clinical study. METHODS AND RESULTS: Pre-Fontan catheterisation data and Fontan pressure measured at the completion were retrospectively collected. Pre-Fontan data were used to calculate the predicted pressure in the Fontan system. The predicted values were compared to the Fontan pressure measured at the Fontan completion and with the needs for fenestration. One hundred twenty-four Fontan patients were retrospectively enrolled (At Fontan: median age 30.73 [24.70-37.20] months, median weight 12.00 [10.98-14.15] kg). Fontan conduit was fenestrated in 78 patients. A poor correlation (r2 = 0.05128) between the measured and predicted data for non-fenestrated patients was observed. In the case of Fontan-predicted pressure <17.59 mmHg, the formula identified a good short-term clinical outcome with a sensitivity of 92%. CONCLUSION: The proposed formula showed a poor capability in estimating the actual pressure into the Fontan system and in identifying patients needing fenestration. As the pressure into the Fontan system is determined by multiple factors, the tested formula could be an additional data in a multi-parametric approach.

The Superior Cavopulmonary Connection: History and Current Perspectives.

The development of the superior cavopulmonary connection is a rich illustration of international influences in congenital cardiac surgery. The bidirectional Glenn and hemi-Fontan procedures have improved survival as both definitive and staged functional single ventricle palliation. The optimal timing of the second-stage superior cavopulmonary procedures varies by center but for low- and intermediate-risk patients, this may be within three to six months after the Norwood procedure. The list of risk factors continues to grow but the most frequently cited factors include atrioventricular valve regurgitation, decreased ventricular function, need for reintervention, and failure to attain nutritional and growth goals. Ongoing prospective, multi-institutional studies, particularly those fostered internationally by the World Society for Pediatric and Congenital Heart Surgery and other associations, will hopefully provide further clarification of the complex management issues related to patients with functional single ventricle physiology.

The Bilateral Bidirectional Glenn Operation as a Risk Factor Prior to Fontan Completion in Complex Congenital Heart Disease Patients.

INTRODUCTION: The Glenn procedure is generally performed as a second-stage palliative procedure toward the completion of Fontan circulation in patients with a functionally univentricular heart. Safe Fontan completion requires normal ventricular function, competent atrioventricular valves, normal pulmonary arteries anatomy, and low pulmonary vascular resistances (PVRs), which is merely an estimation that considers both lungs as a single unit. Clinical observations revealed that patients who previously underwent bilateral bidirectional cavopulmonary anastomosis (b-BCPA) had a stormier postoperative course in respect to other patients with previous unilateral BCPA (u-BCPA) postoperatively after Fontan completion. This retrospective study was designed to compare and analyze the outcomes of patients following Fontan completion with previous u-BCPA versus b-BCPA. PATIENTS AND METHODS: A total of 98 patients were divided into two groups based on the presence or absence of bilateral superior vena cava (SVC). Group 1 included 80 patients with unilateral SVC, and group 2 included 18 patients with bilateral SVC. Univariate and multivariate (SPSS) analyses were performed with regard to mortality and failure. P value of <.05 was considered as significant. RESULTS: Prior to the total cavopulmonary anastomosis operation, the G1 and G2 had similar demographic and physiological findings, ages and weights were 4.3 ± 1.72 years and 15.0 ± 3.71 kg in G1 and 4.8 ± 3.21 years and 17.5 ± 9.76 kg in G2. Mean end-diastolic ventricular pressures (in mm Hg) were 10.50 ± 2.86 in G1 and 10.28 ± 3.07 in G2 and the mean PVRs (in Woods units) were 1.66 ± 1.29 in G1 and 1.49 ± 0.82 in G2. The Stormy postoperative course, Fontan failure, and early mortality were all significantly higher in G2 in respect to G1 ( P value <.05). G1 mortality rate was 3.7%, 3 patients of 80, while in G2, the mortality rate was 22%, 4 patients of 18. Late Fontan failure rates were 6% for G1 patients where two patients developed pulmonary hypertension, two patients developed heart failure, and one patient had protein losing enteropathy (PLE), and 22% for the G2 patients of which two patients developed heart failure, one patient had PLE, and one patient had persistent low systemic venous saturation. CONCLUSIONS: Our results have demonstrated that patients after b-BCPA might have a tendency for worse outcomes upon Fontan completion. The b-BCPA is associated with pulmonary artery bifurcation stenosis and presents multiple sources of pulmonary blood flow where conventional PVR calculation might be imprecise and misleading since it considers the lungs as a single unit. Therefore, b-BCPA engenders correction of the conventional PVR calculation to consider each lung separately. Furthermore, the surgical approach for patients with persistent left SVC and univentricular heart should be modified.

Outcomes of the Conversion of the Fontan-Kreutzer Operation to a Total Cavopulmonary Connection for the Failing Univentricular Circulation.

BACKGROUND: The Fontan-Kreutzer procedure (FK) was widely performed in the past, but in the long-term generated many complications resulting in univentricular circulation failure. The conversion to total cavopulmonary connection (TCPC) is one of the options for treatment. OBJECTIVE: To evaluate the results of conversion from FK to TCPC. METHODS: A retrospective review of medical records for patients who underwent the conversion of FK to TCPC in the period of 1985 to 2016. Significance p < 0,05. RESULTS: Fontan-type operations were performed in 420 patients during this period: TCPC was performed in 320, lateral tunnel technique in 82, and FK in 18. Ten cases from the FK group were elected to conversion to TCPC. All patients submitted to Fontan Conversion were included in this study. In nine patients the indication was due to uncontrolled arrhythmia and in one, due to protein-losing enteropathy. Death was observed in the first two cases. The average intensive care unit (ICU) length of stay (LOS) was 13 days, and the average hospital LOS was 37 days. A functional class by New York Heart Association (NYHA) improvement was observed in 80% of the patients in NYHA I or II. Fifty-seven percent of conversions due to arrhythmias had improvement of arrhythmias; four cases are cured. CONCLUSIONS: The conversion is a complex procedure and requires an experienced tertiary hospital to be performed. The conversion has improved the NYHA functional class despite an unsatisfactory resolution of the arrhythmia.

Outcomes of the Conversion of the Fontan-Kreutzer Operation to a Total Cavopulmonary Connection for the Failing Univentricular Circulation / Resultados da Conversão da Cirurgia de Fontan-Kreutzer para Cavo-Pulmonar Total Devido Falência da Circulação Univentricular

Abstract Background: The Fontan-Kreutzer procedure (FK) was widely performed in the past, but in the long-term generated many complications resulting in univentricular circulation failure. The conversion to total cavopulmonary connection (TCPC) is one of the options for treatment. Objective: To evaluate the results of conversion from FK to TCPC. Methods: A retrospective review of medical records for patients who underwent the conversion of FK to TCPC in the period of 1985 to 2016. Significance p < 0,05. Results: Fontan-type operations were performed in 420 patients during this period: TCPC was performed in 320, lateral tunnel technique in 82, and FK in 18. Ten cases from the FK group were elected to conversion to TCPC. All patients submitted to Fontan Conversion were included in this study. In nine patients the indication was due to uncontrolled arrhythmia and in one, due to protein-losing enteropathy. Death was observed in the first two cases. The average intensive care unit (ICU) length of stay (LOS) was 13 days, and the average hospital LOS was 37 days. A functional class by New York Heart Association (NYHA) improvement was observed in 80% of the patients in NYHA I or II. Fifty-seven percent of conversions due to arrhythmias had improvement of arrhythmias; four cases are cured. Conclusions: The conversion is a complex procedure and requires an experienced tertiary hospital to be performed. The conversion has improved the NYHA functional class despite an unsatisfactory resolution of the arrhythmia.

Resumo Fundamento: O procedimento de Fontan-Kreutzer (FK) foi amplamente realizado no passado, mas a longo prazo gerou muitas complicações, resultando em falha na circulação univentricular. A conversão para conexão cavopulmonar total (CCPT) é uma das opções de tratamento. Objetivo: Avaliar os resultados da conversão de FK para CCPT. Métodos: Revisão retrospectiva de prontuários de pacientes submetidos à conversão de FK para CCPT no período de 1985 a 2016. Significância p < 0,05. Resultados: Operações do tipo Fontan foram realizadas em 420 pacientes durante este período: CCPT foi realizada em 320, técnica de túnel lateral em 82 e FK em 18. Dez casos do grupo FK foram eleitos para conversão em CCPT. Todos os pacientes submetidos à conversão de Fontan foram incluídos neste estudo. Em nove pacientes, a indicação deveu-se a arritmia não controlada e em um devido à enteropatia perdedora de proteínas. A morte foi observada nos dois primeiros casos. O tempo médio de internação na unidade de terapia intensiva (UTI) foi de 13 dias e o tempo médio de internação hospitalar foi de 37 dias. Uma classe funcional pela melhora da New York Heart Association (NYHA) foi observada em 80% dos pacientes em NYHA I ou II. Cinquenta e sete por cento das conversões devido a arritmias tiveram melhora das arritmias; quatro casos foram curados. Conclusões: A conversão é um procedimento complexo e requer que um hospital terciário experiente seja realizado. A conversão melhorou a classe funcional da NYHA, apesar de uma resolução insatisfatória da arritmia.

Younger age remains a risk factor for prolonged length of stay after bidirectional cavopulmonary anastomosis.

OBJECTIVE: This study sets out to determine the influence of age at the time of surgery as a risk factor for post-operative length of stay after bidirectional cavopulmonary anastomosis. METHODS: All patients undergoing a Glenn procedure between January 2010 and July 2015 were included in this retrospective cohort study. Demographic data were examined. Standard descriptive statistics was used. A univariable analysis was conducted using the appropriate test based on data distribution. A propensity score for balancing the group difference was included in the multi-variable analysis, which was then completed using predictors from the univariable analysis that achieved significance of p<0.1. RESULTS: Over the study period, 50 patients met the inclusion criteria. Patients were separated into two cohorts of ⩾4 months (28 patients) and <4 months (22 patients). Other than height and weight, the two cohorts were indistinguishable in their pre-operative saturation, medications, catheterisation haemodynamics, atrioventricular valve regurgitation, and ventricular function. After adjusting group differences, younger age was associated with longer post-operative length of hospitalisation - adjusted mean 15 (±2.53) versus 8 (±2.15) days (p=0.03). In a multi-variable regression analysis, in addition to ventricular dysfunction (ß coefficient=8.8, p=0.05), Glenn procedures performed before 4 months were independently associated with longer length of stay (ß coefficient=-6.9, p=0.03). CONCLUSION: We found that Glenn procedures performed after 4 months of age had shorter post-operative length of stay when compared to a younger cohort. These findings suggest that balancing timing of surgery to decrease the inter-stage period should take into consideration differences in post-operative recovery with earlier operations.

Velocity vector imaging for the assessment of segmental ventricular function in children with a single right ventricle after cavopulmonary anastomosis.

OBJECTIVE: Ventricular function assessment is very important for the treatment and prognostic classification of children with a single right ventricle (SRV) after cavopulmonary anastomosis (CPA). However, unusual ventricular shapes can result in inaccurate measurements. The aim of this study was to evaluate velocity vector imaging (VVI) for assessing segmental ventricular function in children with SRV after CPA. METHODS: Twenty-one children with SRV after CPA and 21 age- and sex-matched children with normal biventricular anatomy and function were included. The longitudinal velocity, displacement, strain and strain rate were measured in the two groups in six segments by VVI. The velocity, displacement, strain and strain rate of the SRVs were compared with max(dp/dt) measured during simultaneous cardiac catheterization in the SRV subjects. RESULTS: The control group consisted of 13 males and 8 females (69% males) with a mean age of 6.7 ± 3.5 years and mean weight of 20.5 ± 6.5 kg, and the study group consisted of 13 males and 8 females with a mean age 6.7 ± 3.7 years and mean weight of 20.6 ± 6.8 kg. Age, weight and sex distribution were similar between the groups (all, p > .05). Strain and strain rate values in all six segments were significantly lower in the study group than in the control group (all, p < .05). The max(dp/dt) of the SRV was 522.84 ± 158.32 mmHg/s, and the strain rate of the basal segment at the rudimentary chamber correlated best with max(dp/dt) (r = 0.74, p < .01). CONCLUSIONS: Segmental ventricular dysfunction was present in children with SRV after CPA, and it could be assessed using VVI.

Chronic In Vivo Test of a Right Heart Replacement Blood Pump for Failed Fontan Circulation.

An implantable rotary blood pump was developed to provide long-term mechanical right heart support for patients who have failing Fontan circulation. The objective of this study was to evaluate the pump in vivo in a 30 day sheep study. Pump speed was set at 3,900 rpm for the duration of the study, and pump power was between 4.3 and 4.6 W. The pump inlet pressures for the superior vena cava (SVC) and inferior vena cava (IVC) were 14 ± 15 and 11 ± 15 mm Hg, respectively, over the duration of the study. Hematocrit remained stable at 30% ± 4%. Partial thromboplastin time (PTT) steadily increased from 30 s preoperatively to a high of 59 s on postoperative day 20, while prothrombin time (PT) remained at 20 ± 2 s for the duration of the study. The implantation and postoperative recovery were successful, and the animal demonstrated normal physiologic pulmonary and venous pressures and cardiac output. On pump inspection, the IVC and SVC inlets were completely clear of any deposits, but there were small thrombi (approximately 0.5 mm diameter) between each of the three rotor blades and along 20% of the parting line of the two volute halves. A complete right heart bypass was performed, postoperative recovery was successful, and the pump demonstrated adequate circulatory support and normal physiologic pulmonary and venous pressures. This study was the first successful test of a right heart replacement device in a chronic animal study.

Congenital intrahepatic portocaval shunts and hypoglycemia due to secondary hyperinsulinism: a case report and review of the literature.

BACKGROUND: Congenital portosystemic shunts present with various associated complications, such as other congenital malformations, hyperammonemia, or hepatopulmonary syndrome. Few cases of associated hypoglycemia have been reported so far and our case, to the best of our knowledge, describes the most severe extent of hypoglycemia. CASE PRESENTATION: We describe the case of a newborn Arab boy with two intrahepatic portosystemic shunts, resulting in severe and persistent hypoglycemia, due to which one of the shunts was closed by interventional radiology whereas the other shunt had already closed spontaneously. CONCLUSIONS: Because he showed elevated levels for insulin and prolonged high insulin levels in an oral glucose tolerance test, our case supports the theory that portocaval shunts cause a reduced hepatic insulin reduction due to the high blood volume bypassing the liver. This case provides further insights into glucose regulation mechanisms of the liver and we suggest a consistent screening for hypoglycemia in patients with congenital portosystemic shunts.