Systemic venous collateral channels causing desaturation after bidirectional cavopulmonary anastomosis: evaluation and management

Pulmonary Complications in Patients With Fontan Circulation: JACC Review Topic of the Week

The Fontan operation has resulted in significant improvement in survival of patients with single ventricle physiology. As a result, there is a growing population of individuals with Fontan physiology reaching adolescence and adulthood. Despite the improved survival, there are long-term morbidities associated with the Fontan operation. Pulmonary complications are common and may contribute to both circulatory and pulmonary insufficiency, leading ultimately to Fontan failure. These complications include restrictive lung disease, sleep abnormalities, plastic bronchitis, and cyanosis. Cyanosis post-Fontan procedure can be attributed to multiple causes including systemic to pulmonary venous collateral channels and pulmonary arteriovenous malformations. This review presents the unique cardiopulmonary interactions in the Fontan circulation. Understanding the cardiopulmonary interactions along with improved recognition and treatment of pulmonary abnormalities may improve the long-term outcomes in this growing patient population. Interventions focused on improving pulmonary function including inspiratory muscle training and endurance training have shown a promising effect post-Fontan procedure.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Assessment of superior cavo-pulmonary anastomoses (Glenn shunt) by cardiac magnetic resonance imaging in comparison with multi-slice computed tomography

Background

Multi-slice computed tomography (MSCT) angiography is the gold standard imaging modality to evaluate the patency of Glenn shunt and the presence of veno–veno collaterals. The goal of this study is to evaluate the ability of two cardiac magnetic resonance imaging (MRI) techniques to assess the patency of Glenn shunt and the presence of veno–veno collaterals compared to MSCT angiography.

Results

Patients with Glenn shunt had MSCT angiography and cardiac MRI using two techniques: TWIST (Time-resolved angiography With Stochastic Trajectories) and the three-dimensional (3D) post-contrast whole heart techniques. MSCT angiography and cardiac MRI images were post-processed for quantitative and qualitative assessment of Glenn shunt and veno–veno collaterals. Our study included 29 patients (17 male, 59%) with Glenn shunt, the median age was 22 years (range 3–36 years). 3D post-contrast whole heart images give similar results compared to MSCT angiography results in the evaluation of Glenn shunt and veno–veno collaterals, 100% agreement in Glenn shunt visualization and agreement was 86.2% in the detection of veno–veno collaterals with a perfect agreement (kappa = 1) as regards their proximal connection to superior vena cava (SVC). While TWIST showed lower agreement compared to MSCT angiography results, 87.5% agreement in Glenn shunt visualization and agreement was 68.9% in the detection of veno–veno collaterals with poor agreement (kappa = 0.266) as regards their proximal connection to SVC.

Conclusions

3D post-contrast whole heart MRI images have similar results as MSCT angiography in the evaluation of superior cavo-pulmonary anastomosis and can be a good and safer alternative to MSCT angiography.

One and One-Half Ventricle Repair: Role for Restricting Antegrade Pulmonary Blood Flow

BACKGROUND

In patients with hypoplastic subpulmonary ventricles, the one and one-half ventricle (1.5V) repair is an alternative to the Fontan procedure. However, in 1.5V-treated patients with pulsatile pulmonary blood flow, superior vena cava (SVC) hypertension or right atrial hypertension may develop. This study aimed to (1) describe patient outcomes after 1.5V repair and (2) determine whether pulmonary artery septation at 1.5V repair confers a lower risk of SVC or right atrial hypertension.

METHODS

This study retrospectively reviewed patients who underwent a 1.5V repair between 1989 and 2020. The primary outcome was transplant-free survival. Secondary outcomes were postoperative SVC hypertension (defined by mean Glenn pressures greater than 17 mm Hg, SVC flow reversal or pulsatility, venovenous collateral vessels, or SVC syndrome) and right atrial hypertension (defined as mean right atrial pressures greater than 10 mm Hg with inferior vena cava and hepatic vein dilation or flow reversal).

RESULTS

A total of 74 patients underwent 1.5V repair at a median age of 29.6 months (interquartile range, 8.9 to 45.5 months). Median follow-up time was 39.9 months (interquartile range, 11.4 to 178.1 months). Transplant-free survival at 10 years was 92.4%. Among survivors, 12% (8 of 69) had right atrial hypertension and 39% (27 of 69) had SVC hypertension on follow-up. Survivors with unseptated pulmonary arteries had a greater risk of SVC hypertension compared with patients with septated pulmonary arteries (44% vs 10%; P = .04). No difference was found in right atrial hypertension between the 2 groups.

CONCLUSIONS

Patients with 1.5V repair avoid Fontan-associated complications with favorable transplant-free survival. However, SVC hypertension remains a significant long-term complication. Pulmonary artery septation at 1.5V repair may reduce the risk of SVC hypertension.

Trans catheter device closure of a large azygos vein in adult patient with systemic venous collateral development after the bidirectional Glenn shunt

Superior cavopulmonary anastomosis is a type of palliative cardiac surgeries that usually done in children with cyanotic and complex congenital heart disease who have single ventricle profile. BDG shunt is staged palliation procedure for single ventricle patients who are candidates for total cavopulmonary connection (TCPC). Sometimes the surgeon misses ligating or intentionally leaves the azygos vein as a fenestration or emergency exit. This allows an abnormal flow from the superior vena cava (SVC into azygos vein). These patients can present progressive desaturation, chest tightness, progressive dyspnea, edema and shortness of breath. Therapeutic options include observation, surgical ligation and trans catheter closure. Because of high risks and extra traumas of surgery and greater chance for difficulties and the feasibility of trans catheter therapy, it is done in some centers as a method of choice.

Balloon angioplasty of bidirectional Glenn anastomosis

OBJECTIVE

We aim to assess the safety and efficacy of the transcatheter balloon dilation of superior cavopulmonary anastomosis (SCPA).

BACKGROUND

SCPA stenosis can lead to impaired pulmonary blood flow, hypoxemia and development of veno-venous collaterals with right-to-left shunt. Balloon dilation of SCPA has been rarely reported and follow-up information is lacking.

METHODS

We performed a retrospective review of patients who underwent cardiac catheterisation and angioplasty of SCPA and reviewed patient's demographics, diagnosis, SCPA surgery and post-operative course, catheterisation haemodynamics, procedural technique, angiography, and the findings of follow-up catheterisation.

RESULTS

Between 2008 and 2017, seven patients showed significant narrowing of SCPA and underwent balloon angioplasty, all of whom had undergone bidirectional Glenn (BDG). Indications for cardiac catheterisation included persistent pleural effusion, hypoxemia, and echocardiographic evidence of BDG stenosis or routine pre-Fontan assessment. Five patients had bilateral SCPA. The procedure was successful in all cases with increase in the stenosis diameter from a median of 3.3 mm (range 1.2-4.7 mm) to a median of 4.7 mm (range 2.6-7.8 mm). All patients had at least one follow-up cardiac catheterisation. Only one patient required repeat angioplasty at the 2.3-month follow-up with no further recurrence. Sustained results and interval growth were noted in all other cases during up to 29 months of follow-up. No adverse events were encountered.

CONCLUSION

Based on our small series, balloon angioplasty of BDG stenosis is feasible and safe and appears to provide sustained improvement with interval growth and only the rare recurrence of stenosis.

Bronchial varices in a child with tricuspid atresia six years post Fontan correction

Tracheal and bronchial varices are rarely found in children. However, they have been described in adults with failing Fontan circuits or secondary to vascular pathology, such as portal and pulmonary hypertension. We report the presentation of haemoptysis and bronchial varices in a child, six years after a Fontan procedure for tricuspid atresia. She had tortuous mediastinal and transpleural arterial collaterals on computed tomography (CT) angiography and cardiac catheterization and subsequently underwent embolization of these collaterals. While the haemoptysis settled post embolization, the bronchial varices persisted on repeat bronchoscopy. She has since been clinically well with no further haemoptysis.

Superior Cavopulmonary Connection: Its Physiology, Limitations, and Anesthetic Implications

The superior cavopulmonary connection (SCPC) or "bidirectional Glenn" is an integral, intermediate stage in palliation of single ventricle patients to the Fontan procedure. The procedure, normally performed at 3 to 6 months of life, increases effective pulmonary blood flow and reduces the ventricular volume load in patients with single ventricle (parallel circulation) physiology. While the SCPC, with or without additional sources of pulmonary blood flow, cannot be considered a long-term palliation strategy, there are a subset of patients who require SCPC palliation for a longer interval than the typical patient. In this article, we will review the physiology of SCPC, the consequences of prolonged SCPC palliation, and modes of failure. We will also discuss strategies to augment pulmonary blood flow in the presence of an SCPC. The anesthetic considerations in SCPC patients will also be discussed, as these patients may present for noncardiac surgery from infancy to adulthood.

Numerical Investigation of the Effect of Additional Pulmonary Blood Flow on Patient-Specific Bilateral Bidirectional Glenn Hemodynamics

The effect of additional pulmonary blood flow (APBF) on the hemodynamics of bilateral bidirectional Glenn (BBDG) connection was marginally discussed in previous studies. This study assessed this effect using patient-specific numerical simulation. A 15-year-old female patient who underwent BBDG was enrolled in this study. Patient-specific anatomy, flow waveforms, and pressure tracings were obtained using computed tomography, Doppler ultrasound technology, and catheterization, respectively. Computational fluid dynamic simulations were performed to assess flow field and derived hemodynamic metrics of the BBDG connection with various APBF. APBF showed noticeable effects on the hemodynamics of the BBDG connection. It suppressed flow mixing in the connection, which resulted in a more antegrade flow structure. Also, as the APBF rate increases, both power loss and reflux in superior venae cavae (SVCs) monotonically increases while the flow ratio of the right to the left pulmonary artery (RPA/LPA) monotonically decreases. However, a non-monotonic relationship was observed between the APBF rate and indexed power loss. A high APBF rate may result in a good flow ratio of RPA/LPA but with the side effect of bad power loss and remarkable reflux in SVCs, and vice versa. A moderate APBF rate could be favourable because it leads to an optimal indexed power loss and achieves the acceptable flow ratio of RPA/LPA without causing severe power loss and reflux in SVCs. These findings suggest that patient-specific numerical simulation should be used to assist clinicians in determining an appropriate APBF rate based on desired outcomes on a patient-specific basis.

A prospective study of risk factors associated with persistent pleural effusion after total cavopulmonary connection with special reference to serum cortisol level

Objectives

The Fontan operation is usually followed by significant pleural effusion. We aimed to study the factors associated with persistent pleural effusion with special reference to serum cortisol levels.

Patients and methods

Thirty-eight patients undergoing the Fontan operation between September 2015 and November 2016 were prospectively studied. Parameters studied included age, weight, symptoms, atrio- ventricular valve regurgitation/stenosis/atresia, ventricular function, pulmonary artery pressures, oxygen saturation, aorto-pulmonary, and veno-venous collaterals, type of Fontan, duration of cardiopulmonary bypass, need for inotropes, duration of mechanical ventilation, conduit size, presence or absence of fenestration, and serum cortisol levels. The latter were measured before and after the Fontan operation and the co-relation between pleural effusion and change in serum cortisol levels was studied.

Results

Mean age at operation was 13.1 ± 5.6 years (median 13 years). Mean duration and amount of pleural drainage was 15.76 ± 13.2 days (median 11.5 days) and 9.15 ± 4.6 mL/kg/day (median 9 mL/kg/day) respectively. Statistically significant risk factors for prolonged pleural effusion were higher pulmonary artery (PA) pressures (r = 0.328, p = 0.003, odds ratio 1.30), higher inotropic score (r = 0.4, p = 0.01), lower rise in serum cortisol (p = 0.03),elevated superior caval venous pressure (CVP) at 6 h (r = 0.44, p = 0.005) and 12 h (r = 0.4, p = 0.01) and higher duration of mechanical ventilation (r = 0.45, p = 0.005).

Conclusions

PA pressures > 15 mmHg, higher inotropic score, higher CVP and lower rise in serum cortisol levels following the Fontan operation were associated with persistent pleural effusion.

Transcatheter occlusion of azygos/hemiazygos vein in patients with systemic venous collateral development after the bidirectional Glenn procedure

OBJECTIVES

To elucidate the feasibility and treatment effects of transcatheter occlusion of the azygos/hemiazygos vein in patients with progressive cyanosis after performing the bidirectional Glenn procedure.

METHODS

From January 2007 to May 2011, transcatheter closure was performed on 9 patients (7 males and 2 females) aged 5-15 years (median 9 years).

RESULTS

A total of 7 azygos veins and 3 hemiazygos veins were occluded successfully. Coils were employed in 4 of the procedures, patent ductus arteriosus (PDA) occluders in 3, atrial septal defect occluders in 2 and a PDA occluder together with coils in 1 procedure. Immediate complete occlusions were achieved in 9 (81.8%) procedures and trivial residual shunt in 2 (18.2%). The femoral artery oxygen saturation (SaO2) rose from 81 [interquartile range (IQR) 75-86%] to 88% (IQR 84-91%).

CONCLUSIONS

Patients with superior vena cava azygos vein collateral channels can be treated successfully by transcatheter occlusion with multiple devices. The device for embolization depends on the extent of the severity of the shunt, the size of the lumen of the azygos vein/hemiazygos vein and the candidate location for occlusion.

Catheter interventions in the staged management of hypoplastic left heart syndrome

AIM

To analyse the current practice and contribution of catheter interventions in the staged management of patients with hypoplastic left heart syndrome.

METHODS

This study is a retrospective case note review of 527 patients undergoing staged Norwood/Fontan palliation at a single centre between 1993 and 2010. Indications and type of catheter interventions were reviewed over a median follow-up period of 7.5 years.

RESULTS

A staged Norwood/Fontan palliation for hypoplastic left heart syndrome was performed in 527 patients. The 30-day survival rate after individual stages was 76.5% at Stage I, 96.3% at Stage II, and 99.4% at Stage III. A total of 348 interventions were performed in 189 out of 527 patients. Freedom from catheter intervention in survivors was 58.2% before Stage II and 46.7% before Stage III. Kaplan-Meier freedom from intervention post Fontan completion was 55% at 10.8 years of follow-up. Post-stage I interventions were mostly directed to relieve aortic arch obstruction--84 balloon angioplasties--and augment pulmonary blood flow--15 right ventricle-to-pulmonary conduit interventions; post-Stage II interventions centred on augmenting size of the left pulmonary artery--73 procedures and abolishing systemic venous collaterals--32 procedures. After Stage III, the focus was on manipulating the size of the fenestration--42 interventions--and the left pulmonary artery -31 procedures.

CONCLUSION

Interventional cardiac catheterisation constitutes an integral part in the staged palliative management of patients with hypoplastic left heart syndrome. Over one-third (37%) of patients undergoing staged palliation required catheter intervention over the follow-up period.

Early Cyanosis After Stage II Palliation for Single Ventricle Physiology

Background:

In the early postoperative period after stage II palliation, patients with single ventricle physiology can have cyanosis due to a variety of causes. This cyanosis can be significant and necessitate cardiac catheterization to determine etiology and attempt treatment. Our objective was to determine the etiology of early postoperative cyanosis and outcomes in patients referred to the catheterization laboratory from the cardiac intensive care unit (CICU) after stage II palliation.

Methods:

We performed a retrospective analysis of all patients referred for cardiac catheterization from the CICU for evaluation of early cyanosis after stage II palliation. Etiology for hypoxemia, treatment strategy, and patient outcomes were examined for each patient.

Results:

Between January 1, 2006, and December 31, 2011, 244 patients underwent stage II palliation of which 22 required cardiac catheterization during the early postoperative period because of severe cyanosis. The etiologies for cyanosis were venovenous collaterals (n = 12), cavopulmonary pathway thrombosis (n = 3), hemi-Fontan pathway baffle leak (n = 2), and undetermined (n = 5). Overall, transplant-free survival to hospital discharge was 50% and survival to hospital discharge with stage II physiology was 32%. Venovenous collateral occlusion, cavopulmonary anastomosis takedown, and addition of a second source of pulmonary blood flow were not associated with improved outcome.

Conclusions:

Regardless of the etiology or treatment strategy, severe cyanosis in the early postoperative period after stage II palliation imparts high mortality and usually indicates failing stage II physiology. Venovenous collateral occlusion and thrombectomy are usually futile, and those who survive have a low likelihood of having stage II physiology at hospital discharge.

A case of tracheal varices in an adolescent patient with cyanotic heart disease

Tracheal varices and bronchial varices are infrequently reported in adults as a complication of an underlying vascular obstruction, including portal hypertension, pulmonary arterial hypertension, or pulmonary venous hypertension. Tracheal varices and bronchial varices have been reported in adults with failing Fontan physiology, but this occurrence is rare in children. We report the unusual presentation of tracheal-bronchial varices due to veno-venous collaterals in an adolescent patient with Glenn physiology for double-inlet left ventricle and portal hypertension secondary to cardiac cirrhosis. We document complete resolution of these varices after heart and liver transplantation.

Persistent left superior vena cava remnant causing cyanosis in a post-Fontan patient

We report the successful surgical closure of a persistent left superior vena cava remnant draining into the pulmonary venous circulation causing cyanosis in a post-Fontan patient who had previously undergone Damus-Kaye-Stansel and bidirectional superior cavopulmonary connection followed by a transcatheter coil occlusion of his persistent left superior vena cava.

Common carotid artery to internal jugular vein shunt for managing hypoxemia after a cavopulmonary shunt

In the present report, we discuss a patient who developed persistent hypoxemia after an attempt at Fontan completion failed. As a bail-out procedure, a left common carotid artery to left internal jugular vein shunt was constructed, after which the hypoxemia was relieved.

Multimodality cardiac imaging of a double chambered right ventricle with intrapulmonary shunting: a case report

Background

Double chambered right ventricle (DCRV) is a relatively rare congenital heart disease, characterized by the abnormal division of the right ventricle into a high-pressure inlet and low-pressure outlet by anomalous muscle bundles. Extra-cardiac right-to-left shunts may present with clinical symptoms in adulthood and should be sought in patients with previous cavo-pulmonary shunt procedures.

Case presentation

We report a case of DCRV in a 29 year old Caucasian male presenting in adulthood with a right-to-left shunt secondary to venous collaterals, following cavopulmonary anastomosis for congenital pulmonary atresia and hypoplastic right ventricle.

Conclusion

Multimodality cardiac imaging using echocardiography, cardiac CT, cardiac MRI and cardiac catheterization is often required for complete characterization of complex congenital heart anomalies in adulthood.

Hypoplastic left heart syndrome: current considerations and expectations

In the recent era, no congenital heart defect has undergone a more dramatic change in diagnostic approach, management, and outcomes than hypoplastic left heart syndrome (HLHS). During this time, survival to the age of 5 years (including Fontan) has ranged from 50% to 69%, but current expectations are that 70% of newborns born today with HLHS may reach adulthood. Although the 3-stage treatment approach to HLHS is now well founded, there is significant variation among centers. In this white paper, we present the current state of the art in our understanding and treatment of HLHS during the stages of care: 1) pre-Stage I: fetal and neonatal assessment and management; 2) Stage I: perioperative care, interstage monitoring, and management strategies; 3) Stage II: surgeries; 4) Stage III: Fontan surgery; and 5) long-term follow-up. Issues surrounding the genetics of HLHS, developmental outcomes, and quality of life are addressed in addition to the many other considerations for caring for this group of complex patients.

Late catheter interventions in hypoplastic left heart syndrome

Interventional cardiology plays a key role in the diagnosis and management of patients with functionally univentricular physiology after the various stages of surgical palliation. The interventions performed are widely variable in type, including angioplasty of stenotic vessels and implantation of stents in stenotic vessels; closure of defects such as collaterals, leaks in baffles, and fenestrations; creation of fenestration; and more. In the setting of venous hypertension associated with stenosis at the Fontan baffle, conduit, or pulmonary arteries, stent implantation is often preferred, as the aim is to eliminate completely the narrowing, given that relatively mild stenosis can have a significant detrimental hemodynamic effect in patients with functionally univentricular circulation. The procedure is highly successful. In patients who fail after Fontan procedure, creation of a fenestration is often performed, with variable technique depending on the underlying anatomic substrate. To increase chances of patency of the fenestration, implantation of a stent is often required, particularly in the setting of an extracardiac conduit. For those patients with cyanosis and favorable Fontan hemodynamics, closure of the fenestration is performed using atrial septal occluder devices with high success rate. Coils compatible with magnetic resonance imaging are used widely to treat collateral vessels, although on occasion other specific embolization tools are required, such as particles or vascular plugs. Postoperative arch obstruction is successfully managed with angioplasty at a younger age, while implantation of a stent in the aorta is reserved for older patients. Specifics of these interventional procedures as applied to the population of patients with functionally univentricular hearts are described in this manuscript.

Management of the postoperative pediatric cardiac surgical patient

OBJECTIVE

To review the salient aspects and latest advances in the management of the postoperative pediatric cardiac patient.

DATA SOURCE

A Medline-based literature source.

CONCLUSION

The practice of pediatric cardiac intensive care has evolved considerably over the last several years. These efforts are the result of a collaborative effort from all subspecialties involved in the care of pediatric patients with congenital heart disease. Discoveries and innovations that are representative of this effort include the extension of cerebral oximetry from the operating room into the critical care setting; mechanical circulatory devices designed for pediatric patients; and surgery in very low birth weight neonates. Advances such as these impact postoperative management and make the field of pediatric cardiac intensive care an exciting, demanding, and evolving discipline, necessitating the ongoing commitment of various disciplines to pursue a greater understanding of disease processes and how to best go about treating them.

Systemic venous collateral channel causing desaturation after bidirectional cavopulmonary anastomosis: percutaneous closure

An infant with cyanotic cardiac disease that was palliated with a bidirectional cavopulmonary shunt developed progressive and worsening cyanosis 5 years after the surgical procedure. A large venous collateral was found to be decompressing the bidirectional Glenn shunt from the superior caval vein to the inferior caval vein and was percutaneously closed with a vascular plug. The unusually large venous collateral, and the excellent outcome associated with percutaneous procedure are discussed.

Venovenous malformation: a common finding after Kawashima operation

OBJECTIVES

It has been reported that systemic venovenous malformation (VVM) can develop in patients with interrupted inferior vena cava (IVC) and univentricular type of congenital heart disease who undergo superior vena cava to pulmonary artery connection (Kawashima operation). These malformations can lead to profound systemic desaturation postoperatively. However, there have been few reports that characterise the prevalence, anatomic details and clinical correlations of these systemic VVM arising after Kawashima operation. In this study, we describe our experience with VVM after Kawashima operation, and discuss issues regarding their evaluation and postoperative management.

METHODS

Eight patients with median age 19 months (range: 5-238) who underwent Kawashima operation were subjected to postoperative angiography, prospectively. Sites of VVM origin and entry, as well as their course, were documented. The presence of pulmonary arteriovenous malformations (AVMs) was also documented.

RESULTS

At median follow-up of 31 months (range: 16-72 months), a total of 14 VVM were found in different supra- and infra-diaphragmatic sites in six patients (75%); four of them had concomitant pulmonary AVM while the remaining two patients had only pulmonary AVM.

CONCLUSIONS

Our findings suggest that systemic VVM can occur frequently after Kawashima operation and can produce significant desaturation postoperatively, and hence we support hepatic incorporation. Performing detailed angiographic studies of the supra- and infra-diaphragmatic systemic veins in routine assessment of patients before Kawashima operation is, probably, warranted.

Right ventricular stiffness constant as a predictor of postoperative hemodynamics in patients with hypoplastic right ventricle: a theoretical analysis

One and a half ventricle repair (1.5VR) is a surgical option for hypoplastic right ventricle (RV). The benefits of this procedure compared to biventricular repair (2VR) or Fontan operation remain unsettled. To compare postoperative hemodynamics, we performed a theoretical analysis using a computational model based on lumped-parameter state-variable equations. We varied the RV stiffness constant (B (RV)) to simulate the various RV hypoplasia, and estimated hemodynamics for a given B (RV). With B (RV) < 150% of normal, cardiac output was the largest in 2VR. With B (RV) > 150%, cardiac output became larger in 1.5VR than in 2VR. With B (RV) > 250%, RV end-diastolic volume was almost the same between 1.5VR and 2VR, and a rapid increase in atrial pressure precluded the use of 1.5VR. These results indicate that the beneficial effect of 1.5VR depends on the RV stiffness constant. Determination of management strategy should not only be based on the morphologic parameters but also on the physiological properties of RV.

Vascular endothelial growth factor in children with cyanotic and acyanotic and congenital heart disease

INTRODUCTION

Vascular endothelial growth factor is a potent stimulator of angiogenesis. Children with cyanotic congenital heart disease often experience the development of widespread formation of collateral blood vessels, which may represent a form of abnormal angiogenesis resulting in increased morbidity and mortality. We undertook the present study to determine whether children with cyanotic congenital heart disease have elevated serum levels of vascular endothelial growth factor compared to children with acyanotic heart disease.

MATERIAL AND METHODS

Serum was obtained from 35 children with cyanotic congenital heart disease and 30 children with acyanotic heart disease. Vascular endothelial growth factor levels were measured in the serum of these patients by sandwich enzyme immunoassay.

RESULTS

Vascular endothelial growth factor was significantly elevated in children with cyanotic congenital heart disease compared to children with acyanotic heart disease (150.3 ±48.1 vs. 85.4 ±18.7 pg/ml, respectively, p < 0.001). In the cyanotic group, oxygen saturation (SaO(2)) was negatively correlated with VEGF (r=-0.631, p < 0.001) while haemoglobin was positively correlated (r=0.781, p = 0.007). No significant correlations were found in the acyanotic group.

CONCLUSIONS

Children with cyanotic congenital heart disease have elevated systemic levels of vascular endothelial growth factor directly related to the degree of cyanosis (SaO(2) and haemoglobin levels). These findings suggest that the widespread formation of collateral vessels in these children may be mediated by vascular endothelial growth factor.

Anatomical and Functional Evaluation of Pulmonary Veins in Children by Magnetic Resonance Imaging

Pulmonary vein pathologies often present a diagnostic challenge. Among the different imaging modalities used for the evaluation of pulmonary veins, magnetic resonance is the most comprehensive in assessing anatomy and pathophysiology at the same time. Bright blood cine sequences and contrast-enhanced magnetic resonance angiography outline the course and connections of the pulmonary veins. Phase-contrast velocity mapping measures flow patterns, velocities, and volumes throughout the pulmonary circulation. This paper reviews contemporary utilization of magnetic resonance in the evaluation of pulmonary venous abnormalities in children, based on our experience over the last 5 years and on that of other investigators. We summarize how magnetic resonance imaging enhances our understanding of pulmonary vein physiology and how it can influence the diagnostic approach to children and adults with a pulmonary venous pathology, and we discuss its limitations.

The off-pump Fontan procedure by simply cross-clamping the inferior caval vein

BACKGROUND

We previously used the Fontan procedure, when applicable, by placing a temporary bypass from the inferior vena cava to the atrium. Alternatively, we have striven to achieve the procedure even without use of a temporary bypass in patients having collaterals between the inferior vena cava and the superior vena cava, so as to simplify the procedure. The azygous vein was intentionally left patent at the bidirectional Glenn procedure in the most recent 9 patients, expecting reasonable venovenous communication at Fontan completion. Surgical results will be described for the preliminary experience.

METHODS

Since 2001, this alternative technique has been attempted in 34 patients undergoing the staged Fontan procedure, and eventually used in 22. Duration between the staged procedures was 4 to 108 months (median, 10 months). We considered that the technique was feasible unless femoral venous pressure exceeded 20 mm Hg immediately after cross-clamping the inferior vena cava. Although catheterization before the Fontan completion illustrated development of venovenous collaterals in 14 patients, oxygen saturation remained greater than 80% throughout the period of the bidirectional Glenn physiology.

RESULTS

In all 22 patients, the extracardiac channel was readily reconstructed with an excellent surgical field of view, without operative mortality. On cross-clamping the inferior vena cava, the systemic circulation could be well maintained by administration of dopamine. Oxygen saturation immediately became approximately 97% to 100%. Maximal pressure gradient was 11 +/- 5 mm Hg between the superior vena cava and the femoral vein. Postoperatively, serum concentration of enzymes did not critically increase (maximal aspartate transaminase, 96 +/- 89 U/L; alanine transaminase, 65 +/- 59 U/L; total bilirubin, 1.8 +/- 1.1 mg/dL; creatine kinase, 437 +/- 230 U/L).

CONCLUSIONS

This alternative technique, when feasible under the current criteria, was simple and did not provide any clinically significant impediments.

Transcatheter closure of dilated left superior vena cava for resolution of late cyanosis following fontan palliation

We report two adolescents with late cyanosis post-Fontan palliation arising from a persistent and dilated left superior vena cava (LSVC) draining into the pulmonary venous circulation. One has undergone successful transcatheter closure of the left superior vena cava while the other is waiting closure. There is a need for long-term follow-up of Fontan patients including adequate clarification of increasing cyanosis which may be correctable.

Enlarged left vitelline vein remnant as a cause of cyanosis after the Fontan procedure: resolution with an Amplatzer vascular plug

A 6-year-old girl with heterotaxy and a functional single ventricle had persistent cyanosis 4 years after a fenestrated Fontan procedure. Cardiac catheterization revealed a large venous fistula from a left-sided hepatic vein to the coronary sinus, resulting in desaturation. The anomalous vein was occluded with an Amplatzer vascular plug.

Recanalisation of bilateral superior vena cava after total cavopulmonary connection. Interventional occlusion with the Amplatzer VSD Occluder

Formation of systemic to pulmonary venous or systemic venous left atrial collaterals frequently occurs in patients after Glenn or Fontan-type operations. Embolization with detachable metal coils is the therapy of choice for the closure of small vessels. These devices however are not appropriate for the occlusion of large collaterals, e. g. recanalized bilateral caval veins. We report two patients who presented late after Fontan-type operations with a gradual decrease in oxygen saturation due to recanalisation of bilateral caval veins. Interventional closure of these large veins was carried out successfully with the use of 8 mm Amplatzer muscular VSD Occluders, resulting in an increase of arterial oxygen saturations.

CONCLUSION

The closure of recanalized bilateral superior caval veins after Fontan procedures is possible without technical problems by means of the Amplatzer muscular VSD Occluder. In order to avoid future formation of venous collaterals via the azygos or hemiazgos system, the occluder should be placed in the vena cava below the orifice of the azygos/ hemiazygos vein.