Systemic oxygen saturation and coagulation factor abnormalities before and after the fontan procedure

[A case of recurrent cerebral infarction in an adult patient with false Taussig-Bing anomaly]

The case was a 53-year-old woman. At birth, she was diagnosed with a false Taussig-Bing anomaly with pulmonary artery stenosis and a single ventricle. However, no cardiac surgery was performed, and conservative treatment was continued by a cardiovascular surgeon even after adulthood. Because of secondary polycythemia and a history of multiple cerebral infarctions, she took anti-platelet drugs and anti-coagulants. However, she was admitted with the diagnosis of cerebral infarction for the fourth time. It was considered that the patient was at high risk of paradoxical cerebral embolism due to cardiac malformation with cyanotic congenital heart disease accompanied by coagulation abnormalities. Considering the pathophysiology, we decided to use aspirin in combination with warfarin.

Increased Risk for Thromboembolism After Fontan Surgery: Considerations for Thromboprophylaxis

The Fontan circulation introduces an increased risk of thromboembolism which is associated with substantial mortality and morbidity. Adverse outcomes of thromboembolic complications post-Fontan surgery vary in both nature and severity, ranging from local tissue infarction and pulmonary embolism to Fontan failure and ischemic stroke. Furthermore, recent studies have identified that subclinical stroke is common yet underdiagnosed in Fontan patients. Fontan patients are commonly treated with antiplatelet agents and/or anticoagulants as primary thromboprophylaxis. Optimal thromboprophylaxis management in the Fontan population is still unclear, and clinical consensus remains elusive despite the growing literature on the subject. This perspective will describe the nature of thromboembolism post-Fontan surgery and provide evidence for the use of both current and emerging thromboprophylaxis options for children and adults living with Fontan circulation.

Thrombosis Prevention and Anticoagulation Management in the Pediatric Patient with Congenital Heart Disease

Thrombosis is one of the most frequent complications affecting children with congenital heart disease (CHD). Palliative and reparative cardiac surgeries are some of the main players contributing to the thrombosis risk in this patient population. Additional risk factors related to the CHD itself (e.g., cardiac dysfunction, arrhythmias, and polycythemia in cyanotic cardiac disorders) can contribute to thrombogenicity alone or combined with other factors. Thrombotic complications have been recognized as a significant cause of morbidity and mortality in this patient population. Here, we provide an overview of the pathophysiology and risk factors for thrombosis as well as the indications for and use of different anticoagulation, antiplatelet, and thrombolytic agents. In addition, we describe some of most common thrombotic complications and their management in the pediatric CHD population.

Risk of Liver Cirrhosis and Hepatocellular Carcinoma after Fontan Operation: A Need for Surveillance

Liver cirrhosis and hepatocellular carcinoma (HCC) are serious late complications that can occur after the Fontan procedure. This study aimed to investigate the cumulative incidence of cirrhosis and HCC and to identify specific features distinguishing HCC from benign arterial-phase hyperenhancing (APHE) nodules that developed after the Fontan operation. We retrospectively enrolled 313 post-Fontan patients who had been followed for more than 5 years and had undergone ultrasound or computed tomography (CT) of the liver between January 2000 and August 2018. Cirrhosis was diagnosed radiologically. The estimated cumulative incidence rates of cirrhosis at 5, 10, 20, and 30 years after the Fontan operation were 1.3%, 9.2%, 56.6%, and 97.9%, respectively. Multiphasic CT revealed that 18 patients had APHE nodules that were ≥1 cm in size and showed washout in the portal venous phase (PVP)/delayed phase, which met current noninvasive HCC diagnosis criteria. Among them, only seven patients (38.9%, 7/18) were diagnosed with HCC. After cirrhosis developed, the annual incidence of HCC was 1.04%. The appearance of washout in the PVP (p = 0.006), long time elapsed since the initial Fontan operation (p = 0.04), large nodule size (p = 0.03), and elevated serum α-fetoprotein (AFP) level (p < 0.001) were significantly associated with HCC. In conclusion, cirrhosis is a frequent late complication after Fontan operation, especially after 10 years, and HCC is not a rare complication after cirrhosis development. Diagnosis of HCC should not be based solely on the current imaging criteria, and washout on PVP and clinical features might be helpful to differentiate HCC nodules from benign APHE nodules.

Venovenous Extracorporeal Life Support in Single-Ventricle Patients with Acute Respiratory Distress Syndrome

There is new and growing experience with venovenous extracorporeal life support (VV ECLS) for neonatal and pediatric patients with single-ventricle physiology and acute respiratory distress syndrome (ARDS). Outcomes in this population have been defined but could be improved; survival rates in single-ventricle patients on VV ECLS for respiratory failure are slightly higher than those in single-ventricle patients on venoarterial ECLS for cardiac failure (48 vs. 32-43%), but are lower than in patients with biventricular anatomy (58-74%). To that end, special consideration is necessary for patients with single-ventricle physiology who require VV ECLS for ARDS. Specifically, ARDS disrupts the balance between pulmonary and systemic blood flow through dynamic alterations in cardiopulmonary mechanics. This complexity impacts how to run the VV ECLS circuit and the transition back to conventional support. Furthermore, these patients have a complicated coagulation profile. Both venous and arterial thrombi carry marked risk in single-ventricle patients due to the vulnerability of the pulmonary, coronary, and cerebral circulations. Finally, single-ventricle palliation requires the preservation of low resistance across the pulmonary circulation, unobstructed venous return, and optimal cardiac performance including valve function. As such, the proper timing as well as the particular conduct of ECLS might differ between this population and patients without single-ventricle physiology. The goal of this review is to summarize the current state of knowledge of VV ECLS in the single-ventricle population in the context of these special considerations.

Risk factors and serological markers of liver cirrhosis after Fontan procedure

Liver cirrhosis (LC), which may result in hepatic failure or cancer, has been reported in patients after Fontan procedure. The purpose of this study was to clarify the frequency and histological characteristics of LC, and to evaluate the risk factors and serological markers of LC with Fontan circulation. Retrospective review of contrast-enhanced CT scans (CT) of the liver was carried out in 57 patients after Fontan procedure. Patients were divided into two groups: LC group (n = 31) and no LC group (n = 26). Age at Fontan procedure, duration after Fontan procedure, catheterization data, and history of failing Fontan circulation were compared between groups. Serological data including γ-GTP and hyaluronic acid were compared. Histology of autopsy specimens was assessed when available. Duration after Fontan procedure was significantly longer in LC group than no LC group. History of failing Fontan circulation was more frequent in LC group than in no LC group. There was no correlation between type of procedure (APC/Bjork/lateral tunnel/TCPC) and LC in this series. Serum hyaluronic acid, γ-GTP, and Forns index were significantly higher in LC group. Significant risk factors for LC were duration after Fontan procedure (>20 years). In autopsy specimens, histopathological changes of LC were observed predominantly in the central venous area. LC diagnosed with CT is frequent in patients long after Fontan procedure, especially after 20 years. Hyaluronic acid and γ-GTP could be useful markers to monitor the progression of liver fibrosis in Fontan patients.

Prevalence and predictors of haemostatic complications in 412 Fontan patients: their relation to anticoagulation and haemodynamics

OBJECTIVES

Our aim in the present study was to determine the prevalence of haemostatic events in our Fontan patients, to identify predictive factors and to determine their association with haemodynamics and anticoagulant therapy.

METHODS

We retrospectively evaluated 424 Fontan patients and examined correlations between postoperative haemodynamics and anticoagulant regimens with haemostatic events.

RESULTS

After exclusion of 12 patients with a mechanical valve at the time of Fontan operation, our 412 patients were sub-divided into 21 groups based on the therapeutic duration of warfarin and antiplatelet agent therapy. During the early 5- to 10-year postoperative period, patients receiving warfarin showed higher central venous pressure and lower arterial oxygen saturation (Sat) (P < 0.05-0.001). During a mean follow-up of 11.2 years, 29 (7.0%) haemostatic events occurred. With regard to haemorrhagic events, haemoptysis was most common (n = 13, 45%), followed by cerebral bleeds in 3 (10%). Of thrombo-embolic events, thrombosis in the Fontan pathway was the most common (n = 7, 24%), followed by cerebral infarction in 3. Early haemorrhagic events were associated with late Fontan operation and use of preoperative renin-angiotensin system blockers, while late events were related to heterotaxy syndrome, male gender and low Sat (P < 0.05-0.01). A low Sat was the only predictor of early postoperative thrombo-embolic events (P = 0.0192). Among the three subgroup analyses of fixed anticoagulant regimens, the most frequent haemorrhagic events were associated with long-term use of warfarin (P = 0.0033). None of the anticoagulant regimens that included warfarin and/or antiplatelet agents were independently associated with haemostatic events throughout the follow-up.

CONCLUSIONS

Anticoagulant regimens in Fontan patients varied widely with a significant trend for warfarin use in patients with impaired haemodynamics. Low arterial oxygenation may predict haemostatic events. The relatively high prevalence of haemorrhagic complications indicates the need for individualized anticoagulant administration throughout the follow-up.

Thrombotic complications and thromboprophylaxis across all three stages of single ventricle heart palliation

OBJECTIVES

To describe the incidence of thrombotic complications across all 3 stages of single ventricle palliation and the association between thromboprophylaxis use and thrombotic risk.

STUDY DESIGN

Two separate cross-sectional studies were performed that included 195 patients born between 2003-2008 and 162 patients who underwent Fontan after 2000.

RESULTS

The incidence of thrombotic complications was 40% and 28% after initial palliation and superior cavopulmonary connection (SCPC), respectively; 5-year freedom from thrombotic complications after Fontan was 79%. Thromboprophylaxis was initiated for 70%, 46%, and 94% of patients after initial palliation, SCPC, and Fontan, respectively. Thromboprophylaxis with enoxaparin (vs no thromboprophylaxis) was associated with a reduction in risk of thrombotic complications after initial palliation (hazard ratio [HR] 0.5, P = .05) and SCPC (HR 0.2, P = .04). Thromboprophylaxis with warfarin was associated with a reduction in thrombotic complications after Fontan (HR 0.27, P = .05 vs acetylsalicylic acid; HR 0.18, P = .02 vs no thromboprophylaxis). Thrombotic complications were associated with increased mortality after initial palliation (HR 5.5, P < .001) and SCPC (HR 12.5, P < .001). Three patients experienced major bleeding complications without permanent sequelae (2 enoxaparin, 1 warfarin).

CONCLUSIONS

Given the negative impact of thrombotic complications on survival, the low risk of serious bleeding complications, and the association between thromboprophylaxis and lowered thrombotic complication risk across all 3 palliative stages, routine use of thromboprophylaxis from the initial palliation to the early post-Fontan period in this population may be indicated.

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.

Prospective study of the incidence and predictors of thrombus in children undergoing palliative surgery for single ventricle physiology

PURPOSE

To determine the incidence and clinical and biomarker predictors of perioperative thrombosis in children with single ventricle physiology undergoing staged palliation.

METHODS

Nineteen patients were enrolled and 16 completed the study. Serial ultrasounds of the central venous system were performed to evaluate for thrombus. Plasma antithrombin III, thrombin-antithrombin complex, protein C, protein S, tissue factor pathway inhibitor, plasminogen activator inhibitor-1, tissue plasminogen activator antigen, D-dimer, soluble CD40 ligand, and urinary thromboxane were measured serially before and after surgery. Cardiopulmonary bypass time, aortic cross clamp time, blood product administration, inotrope score, chest tube output, cardiac function by echocardiography, intensive care unit and hospital lengths of stay, and central venous catheter days were recorded.

RESULTS

The incidence of perioperative thrombus was 31%. Patients who developed a thrombus had poorer preoperative ventricular function (p = 0.03) and longer cardiopulmonary bypass times (p = 0.03) than those who did not develop a thrombus. Preoperative plasma antithrombin III was lower (p = 0.01) and tissue plasminogen activator antigen concentrations were higher (p = 0.02) in patients with a thrombus compared with patients without a thrombus. When measured over time, antithrombin III remained lower (p = 0.002) and tissue plasminogen activator antigen higher (p = 0.005) in those who developed a thrombus compared with those who did not. There were no other statistically significant differences in biomarkers of coagulation between patients with and without thrombosis.

CONCLUSION

One-third of patients undergoing palliative surgery for single ventricle physiology develop thrombosis. Decreased ventricular function, low antithrombin III, and increased tissue plasminogen activator may predict those most suitable for randomized clinical trials of anticoagulation.

Lower incidence of procoagulant abnormalities during follow-up after creation of the Fontan circulation in children

OBJECTIVE

Children who undergo surgery for complex congenital cardiac disease are reported to be at increased thrombotic risk. Our aim was to evaluate long-term changes in the haemostatic system after surgery, to compare markers of activated coagulation in children having surgery with those in a healthy control population, and to relate them to adverse clinical outcome.

PATIENTS AND METHODS

We studied, prior to surgery, the coagulation profiles of a cohort of 28 children admitted for a modified Fontan operation, studying them again after a period of mean follow-up of 9.6 years. Median age at the time of final surgery was 18.5 months, with a range from 12 to 76 months. We compared generation of thrombin, and levels of the activated protein C-protein C inhibitor complex to controls at follow-up. Thrombophilia and clinical outcome were evaluated.

RESULTS

At long-term follow-up, a lower incidence of procoagulant abnormalities was observed compared to that before surgery. Of 27 patients, 3 (11%), but none of 45 controls, had levels of activated protein C-protein C inhibitor complex above the reference range. There were no significant differences in generation of thrombin between patients and controls. No thrombotic events were recorded, and the patients were generally in good clinical condition.

CONCLUSIONS

Overall, haemostasis appeared to be in balance, and less prothrombotic, after surgery. A subset of the cohort did show indications of activated coagulation. The current therapeutic approach seems to be sufficient to protect the majority of patient. New tests of global coagulation, nonetheless, may be helpful in improving identification of individuals at increased thrombotic risk.

Cerebral hemorrhage and vasospasm in a child with congenital heart disease

INTRODUCTION

Intracerebral hemorrhages are relatively rare events in children and cerebral vasospasm after such hemorrhages is even more unusual. Children with structural congenital heart disease are particularly at risk for both thrombotic and embolic events but not to isolated hemorrhages.

DISCUSSION

We report a case of cerebral vasospasm in a child with structural congenital heart disease after a cerebral hemorrhage.

CONCLUSION

This case illustrates that this rare occurrence must be swiftly recognized and treated in order to maximize clinical outcome.