Insights into neonatal thrombosis

Pediatric antiphospholipid syndrome: is it the same as an adult?

IMPORTANCE

Antiphospholipid syndrome in neonates and children is a rare, but in some cases life-threatening condition with arterial and/or venous thrombosis and/or non-thrombotic neurological, skin, ophthalmological and other manifestations.

OBSERVATIONS

This review highlights the available information about the features of pediatric APS, including the rare catastrophic form, the differences between pediatric and adult APS, and the role of genetic thrombophilia in APS manifestation.

CONCLUSIONS AND RELEVANCE

The clinical manifestations and treatment options for APS in children may differ from those in adults, and prescribing therapy can be challenging due to the unique clinical and morphological characteristics of the pediatric patient. Pediatric APS may be a predictor of the development of certain autoimmune diseases and classic manifestations of APS in adulthood, therefore, a revision of the existing criteria for the diagnosis and treatment of APS in children is necessary.

Cerebral venous thrombosis and deep medullary vein thrombosis: Padua experience over the last two decades

BACKGROUND

Cerebral venous thrombosis (CVT) is a cerebrovascular disorder that accounts for 20% of perinatal strokes. CVT incidence ranges from 0.67 to 1.12 per 100,000 newborns, while the incidence of "deep medullary vein thrombosis" (DMVT), a subtype of CVT, cannot be accurately estimated. This study aims to analyze the case history of CVT in the neonatal period, with a specific focus on DMVT.

MATERIALS AND METHODS

Newborns diagnosed with CVT, with or without DMVT, between January 2002 and April 2023, were collected using the Italian Registry of Infantile Thrombosis (RITI). Cerebral MRIs were reviewed by an expert neuroradiologist following a standardized protocol.

RESULTS

Forty-two newborns with CVT were identified, of which 27/42 (64%) had CVT, and the remaining 15/42 (36%) had DMVT (isolated DMVT in 9/15). Symptom onset occurred in the first week of life (median 8 days, IQR 4-14) with a male prevalence of 59%. The most common risk factors for CVT were complicated delivery (38%), prematurity (40%), congenital heart diseases (48%), and infections (40%). Seizures were the predominant presenting symptom in 52% of all cases. Hemorrhagic infarction was higher in cases with isolated DMVT (77%) compared to patients with CVT without DMVT (p = 0.013). Antithrombotic treatment was initiated in 36% of patients. Neurological impairment was observed in 48% of cases at discharge, while 18 out of 31 infants (58%) presented one or more neurological deficits at long term follow up.     Conclusion: DMVT occurs in over a third of neonates with CVT. Multicentric studies are essential to establish standardized protocols for therapy, neuroimaging, and follow-up in these patients.

Effect of hyperbilirubinemia and phototherapy on apoptotic microparticle levels in neonates

OBJECTIVE

We aimed to evaluate the effect of hyperbilirubinemia and phototherapy on total apoptotic, platelet-derived, endothelial-derived, and tissue factor (TF)-positive apoptotic microparticle (MP) levels in neonates with nonhemolytic pathologic hyperbilirubinemia.

METHODS

Thirty-three term neonates with nonhemolytic pathologic hyperbilirubinemia and 25 healthy term neonates were included. MP levels were analyzed by flow cytometry using peripheral blood samples only once for the neonates in the control group and twice for the neonates in the study group (before and after phototherapy). Annexin V-positive MPs were defined as apoptotic MPs. Platelet-derived MPs were defined as those containing CD31. MPs containing CD144 were defined as endothelial-derived MPs, and MPs expressing TF were identified as those containing CD142.

RESULTS

The rates of total apoptotic and endothelial-derived apoptotic MPs were significantly higher in the study group than the control group before phototherapy (P = 0.012 and P = 0.003, respectively) and after phototherapy (P = 0.046 and P = 0.001, respectively). Total apoptotic, platelet-derived, endothelial-derived, and TF-positive apoptotic MPs did not show any significant differences before and after phototherapy in the study group (P = 0.908, P = 0.823, P = 0.748, and P = 0.437, respectively).

CONCLUSIONS

Our study demonstrated that total apoptotic and endothelial-derived apoptotic MPs are increased in cases of nonhemolytic pathologic hyperbilirubinemia. We showed that phototherapy does not have a significant effect on apoptotic MP levels. Further studies are needed to evaluate the risk of elevated apoptotic MPs on the development of thromboembolism in neonates with nonhemolytic pathologic hyperbilirubinemia.

The Prevalence and Associated Risk Factors for Neonatal Thrombocytopenia Among Newborns Admitted to the Neonatal Intensive Care Unit

Background Thrombocytopenia is the most prevalent hematological condition in neonates that develops in the neonatal intensive care unit (NICU). This set of illnesses is caused by either decreased platelet production due to placental insufficiency, increased platelet breakdown (consumption), or a combination of the two causes. Based on platelet count, it is defined as mild, moderate, or severe thrombocytopenia, with early and late onset. Purpose The purpose of this study is to determine the prevalence of thrombocytopenia and the factors that contribute to it in newborns hospitalized in the neonatal critical care unit at the Maternity and Children Hospital in Al Ahsa, Saudi Arabia. Methods This descriptive retrospective cross-sectional study was carried out at the NICU of the Maternity and Children Hospital in Al Ahsa, Saudi Arabia, over the span of one year (August 2022 to August 2023) among hospitalized neonates with thrombocytopenia. Thrombocytopenia is defined as a platelet count of 150,000 or less. These patients were monitored until they recovered or died. Results The inclusion criteria were met by a total of 242 newborns with thrombocytopenia. Half of the neonates (57%) were full-term, with Apgar scores greater than 5 at the first (84%) and fifth (93%) minutes, respectively. The great majority of individuals (84%) experienced early-onset thrombocytopenia of mild severity (62%) and were asymptomatic (93%). The majority of the cases resolved spontaneously, with only 21% requiring platelet transfusion. There was a significant relationship discovered between gestational age and the severity of thrombocytopenia, with very preterm infants having moderate to severe thrombocytopenia, as well as birth weight (p=0.001). Furthermore, neonates with severe thrombocytopenia had a considerably higher mortality rate (p=0.001). Conclusion The mortality and morbidity of newborns with perinatal risk for neonatal thrombocytopenia can be reduced with timely detection of the cause and development of thrombocytopenia, as well as adequate and early care.

The clinical and genetic landscape of early-onset thrombophilia in Japan

OBJECTIVES

To determine the optimal management for early-onset thrombophilia (EOT), the genetic and clinical features of protein C (PC)-, protein S (PS)-, or antithrombin (AT)-deficient patients of ≤20 years of age were studied in Japan.

METHODS/RESULTS

Clinical and genetic information of all genetically diagnosed cases was collected through the prospective, retrospective study, and literature review. One-hundred-one patients had PC (n = 55), PS (n = 29), or AT deficiency (n = 18). One overlapping case had PC- and PS-monoallelic variant. Fifty-five PC-deficient patients (54%) had 26 monoallelic or 29 biallelic variant(s), and 29 (29%) PS-deficient patients had 20 monoallelic or nine biallelic variant(s). None of the patients had AT-biallelic variants. The frequent low-risk allele p.K193del (PC-Tottori) was found in five patients with monoallelic (19%) but not 29 with biallelic variant(s). The most common low-risk allele p.K196E (PS-Tokushima) was found in five with monoallelic (25%) and six with biallelic variant(s) (67%). One exceptional de novo PC variant was found in 32 families with EOT. Only five parents had a history of thromboembolism. Thrombosis concurrently developed in three mother-newborn pairs (two PC deficiency and one AT deficiency). The prospective cohort revealed the outcomes of 35 patients: three deaths with PC deficiency and 20 complication-free survivors. Neurological complications were more frequently found in patients with PC-biallelic variants than those with PC-, PS-, or AT-monoallelic variants (73% vs. 24%, p = .019).

CONCLUSIONS

We demonstrate the need for elective screening for EOT targeting PC deficiency in Japan. Early prenatal diagnosis of PC deficiency in mother-infant pairs may prevent perinatal thrombosis in them.

The Hemostatic System in Newborns and the Risk of Neonatal Thrombosis

Newborns are the most vulnerable patients for thrombosis development among all children, with critically ill and premature infants being in the highest risk group. The upward trend in the rate of neonatal thrombosis could be attributed to progress in the treatment of severe neonatal conditions and the increased survival in premature babies. There are physiological differences in the hemostatic system between neonates and adults. Neonates differ in concentrations and rate of synthesis of most coagulation factors, turnover rates, the ability to regulate thrombin and plasmin, and in greater variability compared to adults. Natural inhibitors of coagulation (protein C, protein S, antithrombin, heparin cofactor II) and vitamin K-dependent coagulation factors (factors II, VII, IX, X) are low, but factor VIII and von Willebrand factor are elevated. Newborns have decreased fibrinolytic activity. In the healthy neonate, the balance is maintained but appears more easily converted into thrombosis. Neonatal hemostasis has less buffer capacity, and almost 95% of thrombosis is provoked. Different triggering risk factors are responsible for thrombosis in neonates, but the most important risk factors for thrombosis are central catheters, fluid fluctuations, liver dysfunction, and septic and inflammatory conditions. Low-molecular-weight heparins are the agents of choice for anticoagulation.

50 Years of Pediatric Hemostasis: Knowledge, Diagnosis, and Treatment

Studies from the past 50 years have contributed to the expanding knowledge regarding developmental hemostasis. This is a dynamic process that begins in the fetal phase and is characterized by physiological variations in platelet counts and function, and concentrations of most coagulation factors and the native coagulation inhibitors in early life, as compared with adulthood. The developmental hemostasis studies since the 1980 to 1990s established the laboratory reference values for coagulation factors. It was only a decade or two later, that thromboelastography (TEG) or (rotational thromboelastometry [ROTEM]) as well as thrombin generation studies, provided special pediatric reference values along with the ability to evaluate clot formation and lysis. In addition, global whole blood-based clotting assays provided point of care guidance for proper transfusion support to children hospitalized in intensive care units or undergoing surgery. Although uncommon, thrombosis in children and neonates is gaining increasing recognition, typically as a secondary complication in sick children. Bleeding in children, and particularly intracerebral hemorrhage in newborns, still represent a therapeutic challenge. Notably, our review will outline the advancements in understanding developmental hemostasis and its manifestations, with respect to the pathophysiology of thrombosis and bleeding complications in young children. The changes of transfusion policy and approach to thrombophilia testing during the last decade will be mentioned. Subsequently, a brief summary of the data on anticoagulant treatments in pediatric patients will be presented. Finally, we will point out the 10 most cited articles in the field of pediatric and neonatal hemostasis.

Application of a clinical decision rule and laboratory assays in pediatrics: Adult heparin-induced thrombocytopenia

BACKGROUND

Heparin-induced thrombocytopenia (HIT) is rare among pediatric patients. The diagnosis of HIT depends upon clinical decision tools to assess its pretest probability, supported by laboratory evidence of anti-platelet factor 4 (anti-PF4)/heparin antibodies.

AIMS

To compare the use of the 4Ts score clinical decision tool, clinical characteristics, and laboratory findings between pediatric and adult patients with suspected HIT.

METHODS

We compiled all pediatric patients in our center for whom HIT testing was performed during the years 2015-2021. These were compared with a cohort of consecutive adult patients. Laboratory diagnosis of HIT was performed with particle gel immunoassay (PaGIA) as screening test and confirmed by an automated latex-enhanced immunoturbidimetric assay (LIA) and/or by functional flow cytometry assay (FCA).

RESULTS

The cohort included 34 children (under 18 years) and 105 adults. Adults mostly received heparins for thromboembolism prophylaxis and treatment (72.4%, n = 76), and were more frequently treated with low-molecular-weight heparin (LMWH). Children were mostly exposed during cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO, 61.8%, n = 21), and were more frequently treated with unfractionated heparin (UFH). Compared with adults, children had significantly higher 4Ts scores. Nevertheless, adults had a slightly higher rate of a positive diagnosis of HIT. Six out of 16 adults with confirmed HIT presented with thrombosis (37.5%), whereas all three pediatric patients with HIT presented with thrombosis (p = .087).

CONCLUSIONS

4Ts scores are higher in children compared with adult patients for whom laboratory tests for HIT were obtained. A potentially higher incidence of thrombosis in children with HIT may be attributable to the severity of underlying illness.

Data mining for prothrombin time and international normalized ratio reference intervals in children

Reference intervals (RIs) help physicians in differentiating healthy from sick individuals. The prothrombin time (PT) and International normalized ratio (INR) fluctuate in coagulation pathway defects and have interlaboratory variability due to the instrument/reagent used. As direct method is difficult in children, we chose an indirect data mining method for the determining PT/INR RIs. The indirect method overcomes the substantial financial and logistic challenges, and ethical restrictions in children, moreover, allows partitioning in more fine-grained age groups. Prothrombin Time/INR measurements performed in patients aged birth-18 years between January 2013 and December 2020, were retrieved from laboratory management system of the Aga Khan Hospital. Reference intervals were computed using an indirect KOSMIC algorithm. The KOSMIC package function on the assumption that the non-pathologic samples follow a Gaussian distribution (after Box-Cox transformation of the data), following an elaborate statistical process to isolate distribution of physiological samples from mixed dataset. A total of 56,712 and 52,245 values were retrieved for PT and INR respectively. After the exclusion of patients with multiple specimens obtained during the study period, RIs were calculated for 37,356 (PT) and 37,192 (INR) children with stratification into 9 age groups. A comparison of 2.5th and 97.5th percentile results with those of established RIs from SickKids Handbook of Pediatric Thrombosis and Hemostasis demonstrated good agreement in between different age groups. This study supports data mining as an alternate approach for establishing PT/INR RIs, specifically in resource-limited settings. The results obtained are specific to studied population and instrument/reagent used. The study also allows understanding of fluctuations in coagulation pathways with increasing age and hence better clinical decision-making based on PT and INR results.

Modern Aspects of Anticoagulation System Disorders Diagnosis in Children with Different Polymorphisms in Coagulation Genes. Initial Results

Background. Hemostatic system pathology is topical and poorly studied issue in pediatrics. One of the main causes of coagulation pathway disorders associated with thrombotic events is abnormality in various parts of the hemostatic system. Vascular accidents are commonly caused by anticoagulation system factors deficiency. Conventionally, thrombosis is a common event in adult patients, and there is no adequate attention to disorders of primary physiological anticoagulants system in children. More often acquired anticoagulant proteins deficiency develops in presence of various pathological conditions, especially after the past infectious diseases. All these diseases (thrombophilia, trombotic events, cardiovascular pathology, nervous system diseases, genetic diseases) can occur separately and in association with each other, plus clinical picture of coagulation events may be similar. Objective. The aim of the study is to evaluate changes in the physiological anticoagulants system in children with different pathologies who have polymorphic variants in coagulation genes and who had new coronavirus infection. Methods. The study included 33 children who had severe coronavirus infection in family clusters and had severe chronic pathology potentially associated with disorders of the coagulation system (nervous system damage, hypertrophic cardiomyopathy, hereditary monogenic syndromes, hemato-mesenchymal dysplasia syndrome). All children underwent complete examination including clinical examination, laboratory, and instrumental diagnostics. Results. Preliminary study results indicate significant incidence of polymorphic variants in coagulation genes (one third of children with various diseases from the study). Some children had decreased activity of anticoagulation system glycoproteins (from 6% to 36%) that confirmed the topicality of the examination of anticoagulation system factors deficiency and the need for further dynamic follow-up, as well as revealing of trombophilia predictors in children in selected target groups. Study on revealing anticoagulation system disorders and mutations in coagulation genes will predict the risk of thrombotic disorders. Conclusion. The obtained results have confirmed the significant role of the ongoing study for comprehensive assessment of hemostatic system disorders in children. That will allow us to optimize the approach to diagnosis and personalize the management strategy for patients with different chronic pathologies and disorders of the natural anticoagulants system. The study is currently ongoing.

Clinical Characteristics of Venous Thrombosis Associated with Peripherally Inserted Central Venous Catheter in Premature Infants

Background: This study aimed to analyze clinical characteristics and risk factors for peripherally inserted central catheter (PICC) placement in premature infants. Materials: This study included seven premature infants who were hospitalized in the neonatal intensive care unit (NICU) of Peking University Third Hospital from 1 January 2014–30 June 2021, and suffered PICC-related venous thrombosis. The control group included premature infants (n = 56) matched (1:8) by the following: Did not experience venous thrombosis; born with a similar gestational age (±2 w), birth weight (±200 g); and received PICC catheterization in the same period (±4 w). Clinical neonatal data were collected through the hospital electronic medical record system and analyzed using SPSS version 23. Results: The incidence of PICC-related thrombus was 0.23% (7/3043. Univariate analysis revealed that, compared to the non-thrombotic group, mothers in the thrombosis group had autoimmune diseases (χ² = 9.844, p = 0.030) and used anticoagulative drugs during pregnancy (χ² = 8.036, p = 0.025). The corrected gestational age when PICC-related thrombosis occurred in the thrombosis group was 32 + 6 (30 + 1, 34 + 1) weeks. The average time from catheter placement to thrombosis was 5 (1, 12) days. Among infants, 85.7% (6/7) experienced deep vein thrombosis, of which four were in the lower extremity veins; three occurred within 2 days after central venous catheter extubation, and four occurred during central venous catheter indwelling. The clinical manifestations of thrombosis include skin edema, color changes, and skin temperature changes in the affected limbs. The seven neonates had normal coagulation at the time of thrombus diagnosis, but D-dimers significantly increased 1–2 days after thrombosis, returning to normal 5–8 days after thrombus. The thrombus persisted for 4.5 (3, 8) days. All seven neonates were treated with low molecular weight heparin calcium anticoagulation for 10 (3, 17) days and recovered completely. Conclusions: PICC-related thrombosis occurred within 1 week after catheter placement, and thrombosis more likely happened in infants whose mothers had autoimmune disease. When this high-risk factor exists and the patient has been intubated for 1 week and has sudden swelling in the intubated limb, venous ultrasound should be performed immediately to diagnose, and treatment should be provided in a timely manner to reduce adverse events.

Successful Use of Thrombolysis in an Extremely Low Birth Weight, Premature Infant With Aortic Thrombosis

BACKGROUND

Severe neonatal aortic thrombosis is rare but can lead to significant morbidity or death if inadequately treated. Thrombolytic therapy is indicated for thrombi which are life-threatening, organ-threatening, or limb-threatening, but dosing consensus has not been established.

OBSERVATION

We report a case of a 700 g preterm neonate with spontaneous intestinal perforation who developed an occlusive aortic thrombus with signs of limb ischemia. He was treated successfully with tissue plasminogen activator without hemorrhagic complications. He was started at a dose of 0.06 mg/kg/h and received a maximum dose of 0.3 mg/kg/h. Long-term follow-up at 3 years and 3 months showed no negative sequelae.

CONCLUSION

Alteplase may be considered in premature, extremely low-birth weight infants with careful assessment of risk and benefits, along with frequent surveillance and supportive care.

Use of thrombolytic agents to treat neonatal thrombosis in clinical practice

Among children, neonates have the highest incidence of thrombosis. Thrombolytic agents are used for the management of life and/or organ-threatening thrombosis. Literature on the efficacy and safety of thrombolytic agents in neonates is limited. We reviewed the evidence on dosing, administration, monitoring and treatment duration of tissue plasminogen activator (tPA), streptokinase and urokinase (URK) in neonates (≤ 28days). A systematic literature search was conducted of current databases from inception until 31 March 2021. The initial search yielded 6881 articles and 18 were retained for review. tPA, streptokinase and URK was utilized in 12, seven and four studies on 115, 51 and 16 patients, respectively. The dose range for tPA, streptokinase and URK was 0.01 -0.6 mg/kg/h, 50-2000 and 1000-0 000 units/kg/h, respectively, and treatment duration ranged from 30 min to 30 days. This is the first study to objectively summarize the efficacy and safety of thrombolytic agents in neonates. Overall, thrombolysis was associated with 87.9% complete or partial thrombus resolution and 7.4% recurrence risk. The bleeding risk associated with thrombolytic agents was 23.1% on pooled analysis, which is higher than other anticoagulants. Larger prospective studies are required to determine effective dosing regimens of these therapeutic drugs and further clarify their efficacy and safety. Blood Coagul Fibrinolysis 33:000-000 Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.

Cerebral Venous Sinus Thrombosis in Preterm Infants

BACKGROUND:

Neonatal cerebral venous sinus thrombosis (CVST) can lead to brain injury and neurodevelopmental impairments. Previous studies of neonatal CVST have focused on term infants, and studies of preterm infants are lacking. In this study, we examined the clinical and radiological features, treatment and outcome of CVST in preterm infants.

METHODS:

This was a retrospective, consecutive cohort study of preterm infants (gestational age <37 weeks) with radiologically confirmed CVST. All magnetic resonance imaging/MRV and CT/CTV scans were re-reviewed to study thrombus characteristics and pattern of brain injury. Outcome was assessed by the validated pediatric stroke outcome measure at the most recent clinic visit.

RESULTS:

Twenty-six preterm infants with CVST were studied. Of these, 65% were moderate-late preterm (32–37 weeks), 27% very preterm (28–32 weeks), and 8% extreme preterm (<28 weeks). Most (73%) were symptomatic at presentation with seizures or abnormal exam. Transverse (85%) and superior sagittal (42%) sinuses were common sites of thrombosis. Parenchymal brain injury was predominantly periventricular (35%) and deep white matter (31%) in location. Intraventricular hemorrhage occurred in 46%. Most infants (69%) were treated with anticoagulation. No treated infant (including eleven with pretreatment hemorrhage) had new or worsening post-treatment hemorrhage. Outcomes ranged from no deficits (50%), mild-moderate (25%), and severe (25%) impairment.

CONCLUSIONS:

In our sample of preterm infants with CVST, more than one-quarter were asymptomatic. White matter brain lesions predominated and one-half had neurological deficits at follow-up. Anticoagulation of preterm CVST in this small cohort appeared to be safe. Larger studies of preterm CVST are needed.

Epidemiology, diagnosis and management of neonatal thrombosis: a single-center cohort study

The incidence of neonatal venous and arterial thrombosis ranges from 6.9 to 15/1000 neonatal ICU (NICU) admissions, and is likely an underestimate based on population demographics, frequency of surveillance and vascular catheterization. This retrospective study involving 234 infants reviewed the epidemiology, diagnosis, and management of neonatal thrombosis in a single, tertiary care institution over more than 10 years. The incidence of thrombosis was 25/1000 NICU admissions, with a preterm to term infant ratio of 1.5 : 1 and a slightly higher proportion of male sex (55.1%). The mean (range) gestational age and birth weight was 33.8 weeks (23-41.6) and 2360 g (512-5890). The median age (IQR) of thrombus diagnosis was 7 (3-17) days. Portal vein thrombosis was most prevalent (59.4%) compared with other sites of thrombosis. Almost three-quarter (171/234; 73.1%) of the thrombotic episodes were line-related, while infection and surgery were associated with 19.7% (46/234) and 10.7% (25/234), respectively. Twenty patients (8.3%) were screened for thrombophilia and 3 were positive; 2 for antithrombin deficiency, 1 for factor V Leiden gene mutation. Subjects were followed with imaging for 3 months with a treatment duration, mean (IQR) of 33.5 (10.8-42.5) days. Complete clot resolution was significantly higher in the anticoagulation group (48%; 17%; P = 0.03) compared with untreated patients. No group difference was noted for partial thrombus resolution (33.3%; 12.4%; P = 0.313). Anticoagulation halted thrombus progression (2.6 versus 12.4%; P = 0.025) and fewer treated patients failed to attend follow-up visits (6.5 versus 18.6%; P = 0.022). Well designed, multicenter prospective studies with larger sample sizes are required to confirm these findings.

Vena Cava Thrombosis after Congenital Diaphragmatic Hernia Repair: Multivariate Analysis of Potential Risk Factors

INTRODUCTION

 The treatment of newborns with congenital diaphragmatic hernia (CDH) is associated with a significant complication rate. Information on major thrombotic complications and their incidence in newborns with CDH is lacking. The aims of our analysis were to evaluate the frequency of vena cava thrombosis and to determine its predictors within a consecutive series of patients with CDH.

MATERIALS AND METHODS

 We retrospectively analyzed charts of all neonates of our department that underwent CDH repair from 2007 to 2021, focusing on vena cava thrombosis. Vena cava thrombosis was diagnosed sonographically and classified as complete or partial venous occlusion. Complete occlusion was confirmed by cavography. Variables evaluated were CDH side, liver position, central vein line, surgical approach, and extracorporeal membrane oxygenation (ECMO). Univariate and multivariate tests were utilized.

RESULTS

 Among 57 neonates who underwent CDH repair, vena cava thrombosis was diagnosed in 14 (24.6%), seven of whom had complete occlusion of the vena cava. Factors associated with vena cava thrombosis were femoral or saphenous venous catheter (p = 0.044), right sided CDH (p = 0.027) and chylothorax (p < 0.0001). ECMO was not associated with vena cava thrombosis. Seven patients (50%) with vena cava thrombosis were treated interventionally with angioplasty and seven (50%) conservatively with anticoagulation only. Mortality was not higher in patients with compared with patients without vena cava thrombosis.

CONCLUSION

 The incidence of vena cava thrombosis in newborns with CDH in our series is high. Routine postoperative abdominal sonography focusing on vena cava thrombosis is mandatory in all patients with CDH. Patients who developed vena cava thrombosis were more likely to develop chylothorax after CDH repair. Considering the good outcome of medical therapy of partial vena cava thrombosis, it may be discussed whether low dose anticoagulation may be provided to all newborns with CDH.

Venous Thromboembolism in Premature Neonates

While the incidence of venous thromboembolism (VTE) is lower among children than adults, the newborn period is one of two bimodal peaks (along with adolescence) in VTE incidence in the pediatric population. Most VTE cases in neonates occur among critically ill neonates being managed in the neonatal intensive care unit, and most of these children are born premature. For this reason, the presentation, diagnosis, management, and outcomes of VTE among children born premature deserve special emphasis by pediatric hematologists, neonatologists, pharmacists, and other pediatric health care providers, as well as by the scientific community, and are described in this review.

Clinical Impact of Heritable Thrombophilia on Neonatal-Onset Thromboembolism: A Nationwide Study in Japan

OBJECTIVE

To clarify the incidence and genetic risk of neonatal-thromboembolism, we conducted a nationwide study exploring the impact of thrombophilia on neonatal-thromboembolism in Japan.

STUDY DESIGN

A questionnaire survey was conducted for perinatal centers in Japan, focusing on the clinical expression, genotype, treatment, and outcome of patients who developed thromboembolism within 28 days of birth from 2014 to 2018.

RESULTS

The estimated incidence of neonatal-thromboembolism was 0.39 cases per 10 000 live births. Intracranial lesions and purpura fulminans occurred in 66 and 5 of 77 patients, respectively. Fifty-eight (75.3%) infants presented within 3 days after birth. Four (5.2%) died, and 14 (18.2%) survived with disability. At the diagnosis, <20% plasma activity of protein C was noted in 16 infants, protein S (in 2), and antithrombin (in 1). Thirteen genetic tests identified 4 biallelic and 5 monoallelic protein C-variants but no protein S- or antithrombin-variants. Protein C-variants had purpura fulminans (P < .01), ocular bleeding (P < .01), positive-family history (P = .01), and death or disability (P = .03) more frequently than others. Protein C-variants were independently associated with disability (OR 5.74, 95% CI 1.16-28.4, P = .03) but not death. Four biallelic variants had serious thrombotic complications of neurologic disability, blindness, and/or amputation. Three monoallelic variants survived without complications. The only protein C-variant death was an extremely preterm heterozygote infant.

CONCLUSIONS

Monoallelic protein C-variants had a higher incidence of neonatal-thromboembolism than biallelic variants. Thrombophilia genetic testing should be performed in the setting of neonatal-thromboembolism and low protein C to identify the underlying genetic defect.

Neonatal thrombosis: risk factors and principles of prophylaxis

Data analysis on the pathogenesis and risk factors of neonatal thrombosis was carried out. The main risk factor of any neonatal thrombosis is central catheter installment, but other maternal, fetal and neonatal factors should be taken into consideration. We discuss the epidemiology of neonatal thrombosis and the main features of the hemostasis system in newborns, the most significant risk factors, including genetic and acquired thrombophilia. We consider the von Willebrand factor activity and ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) level in the development of neonatal thrombotic microangiopathy. Finally, we discuss the basic principles of prevented neonatal thrombosis by using low molecular weight heparins.

Research advances in neonatal cerebral sinovenous thrombosis

Neonatal cerebral sinovenous thrombosis (CSVT) is a cerebrovascular disease with a seriously underestimated incidence rate. Due to a lack of specific clinical manifestations and the low sensitivity of conventional imaging examinations, it has long been considered a rare disease in neonates. In recent years, the development of magnetic resonance technology has improved the diagnostic rate of CSVT. This article reviews the research advances in intracranial venous anatomy of neonates and clinical manifestations, imaging features, treatment, and prognosis of CSVT and deep venous thrombosis, in order to improve the understanding and to make correct diagnosis and treatment of neonatal CSVT.

Risk factors determining central venous access device-associated deep vein thrombosis resolution in children: a retrospective study

The risk factors associated with the probability of central venous access device (CVAD)-associated deep vein thrombosis (DVT) resolution have been hardly evaluated in children. Current guidelines suggest anticoagulation for a maximum of 3 months in patients with provoked DVT if the provoking factor is resolved. To know if the thrombus will resolve after anticoagulant therapy will help to choose whether to initiate and/or continue this treatment or not. We did a retrospective study of 85 pediatric patients (45 girls, 40 boys) with CVAD-associated DVT to examine the risk factors associated with lack of thrombus resolution in the first 6 months after diagnosis. Sixty-two children had their thrombosis resolved after a median of 50 days (p25-p75 25-97) since diagnosis. In multivariate analysis, variables significantly associated with no resolution were total occlusion (OR 12.50, 95% CI 2.99-52.14, p=.001), location in upper extremity, head, and neck veins (OR 17.70, 95% CI 1.64-191.43, p=.018); collateral circulation in the first 45 days after diagnosis (OR 33.55, 95% CI 2.42-464.71, p=.009); and having between 0 and 3 prothrombotic risk factors at diagnosis (OR 6.20, 95% CI 1.21-31.75, p=.029).Conclusion: CVAD-associated DVT resolution in children in the first 6 months since diagnosis was significantly lower if the thrombosis was occlusive, if it was located in the upper extremity, head, and neck veins; if collateral circulation was seen on ultrasound in the first 45 days; and/or when the patient showed less prothrombotic risk factors at diagnosis. What is Known: • The risk factors associated with central venous access device-associated deep vein thrombosis resolution have been hardly evaluated in children. • Current guidelines suggest anticoagulation for a maximum of 3 months in provoked vein thrombosis if the provoking factor is resolved. What is New: • Thrombus resolution was lower if it was occlusive, located in the upper extremity veins, if collateral circulation was seen, and with less prothrombotic risk factors at diagnosis. • To know if the thrombus will resolve after anticoagulation will help to choose whether to initiate and/or continue it or not.

Neonatal Encephalopathy: Beyond Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy is a clinical syndrome of neurologic dysfunction that encompasses a broad spectrum of symptoms and severity, from mild irritability and feeding difficulties to coma and seizures. It is vital for providers to understand that the term "neonatal encephalopathy" is simply a description of the neonate's neurologic status that is agnostic to the underlying etiology. Unfortunately, hypoxic-ischemic encephalopathy (HIE) has become common vernacular to describe any neonate with encephalopathy, but this can be misleading. The term should not be used unless there is evidence of perinatal asphyxia as the primary cause of encephalopathy. HIE is a common cause of neonatal encephalopathy; the differential diagnosis also includes conditions with infectious, vascular, epileptic, genetic/congenital, metabolic, and toxic causes. Because neonatal encephalopathy is estimated to affect 2 to 6 per 1,000 term births, of which HIE accounts for approximately 1.5 per 1,000 term births, (1)(2)(3)(4)(5)(6) neonatologists and child neurologists should familiarize themselves with the evaluation, diagnosis, and treatment of the diverse causes of neonatal encephalopathy. This review begins by discussing HIE, but also helps practitioners extend the differential to consider the broad array of other causes of neonatal encephalopathy, emphasizing the epidemiology, neurologic presentations, diagnostics, imaging findings, and therapeutic strategies for each potential category.

Portal vein thrombosis and food protein-induced allergic proctocolitis in a premature newborn with hypereosinophilia: a case report

Background

Peripheral blood eosinophilia is identified in numerous medical conditions associated with allergic, infectious, and inflammatory processes mostly as reactive eosinophilia with or without tissue eosinophilia. In hospitalized neonates, eosinophilia is common with an inverse relationship with gestational age and occurs solely as mild eosinophilia in the majority of cases. In the literature, eosinophilia has been proposed as a possible risk factor for venous thromboembolism. However, few reports are found on thromboembolic events including portal vein thrombosis (PVT) associated with eosinophilia in the newborn period.

Neonates, particularly preterm infants, are vulnerable to thrombosis due to the immature and developing hemostatic system with little reserve capacity, which occurs as catheter-related thrombosis in most cases.

Case presentation

A male newborn at 34^+ 5 weeks’ gestation presented with a left portal venous thrombus and hematochezia after initial cow’s milk feeding in the setting of blood hypereosinophilia for a prolonged period of time without central venous catheterization. The infant was diagnosed with PVT and food protein-induced allergic proctocolitis (FPIAP) and showed complete resolution of the conditions with expectant management with food avoidance, including the normalized eosinophil count.

Conclusions

Our experience suggests that in the setting of hypereosinophilia with a prolonged duration in premature neonates, FPIAP should be suspected in case of hematochezia in otherwise healthy infants, and considering the increased thrombotic risk by the hypereosinophilia and premature newborn status, evaluation for neonatal thrombosis may be needed, including PVT with the potential risk for the more serious, but uncommon, late complications encompassing portal hypertension.

Evaluation of Heparin Anti-Factor Xa Levels Following Antithrombin Supplementation in Pediatric Patients Supported With Extracorporeal Membrane Oxygenation

OBJECTIVE

Thrombotic events are potential complications in patients receiving extracorporeal membrane oxygenation (ECMO) necessitating the use of systemic anticoagulation with heparin. Heparin works by potentiating the effects of antithrombin (AT), which may be deficient in critically ill patients and can be replaced. The clinical benefits and risks of AT replacement in children on ECMO remain incompletely understood.

METHODS

This single-center, retrospective study reviewed 28 neonatal and pediatric patients supported on ECMO at a tertiary care hospital between April 1, 2013, and October 31, 2014, who received at least 1 dose of AT during their ECMO course. The primary outcome of the study was the change in anti-factor Xa levels after pooled human AT supplementation. Secondary outcomes included the percentage of anti-factor Xa levels within the therapeutic range surrounding AT administration; survival to decannulation; 30 days after cannulation and discharge; time to first circuit change; and incidence of bleeding and thrombotic events.

RESULTS

A total of 78 doses of AT were administered during the study period. The mean increase in anti-factor Xa level following AT administration in patients without a ≥10% concurrent change in heparin was 0.075 ± 0.13 international units/mL. A greater percentage of anti-factor Xa levels were therapeutic for the 48 hours following AT administration (64.2% vs 38.6%). Survival and adverse events were similar to Extracorporeal Life Support Organization averages, with the exception of a higher incidence of intracranial hemorrhage.

CONCLUSIONS

Patients experienced a small but significant increase in anti-factor Xa level and a greater percentage of therapeutic anti-factor Xa levels following AT supplementation.

Incidence of VTE in asymptomatic children with deficiencies of antithrombin, protein C, and protein S: a prospective cohort study

Although antithrombin, protein C, and protein S defects are well-recognized inherited risk factors for venous thromboembolism (VTE) in adults, whether they predispose children to these vascular disorders as well is undefined. In a prospective cohort study, we assessed the incidence of spontaneous and risk period-related VTE in children who were family members of adults who, after an episode of symptomatic VTE, had then been identified as carriers of these abnormalities. A total of 134 children from 87 families were enrolled. Seventy (51.5%) of these children were carriers of an inherited defect, and the remaining 64 were not; the mean observation period was 4 years (range, 1-16 years) and 3.9 years (range, 1-13), respectively. Sixteen risk periods were experienced by carriers, and 9 by noncarriers. Six VTE occurred in the 70 carriers during 287 observation-years, accounting for an annual incidence of 2.09% patient-years (95% confidence interval, 0.8-4.5), compared with none in the 64 noncarriers during 248 observation-years. Of the 14 children with thrombophilia who experienced a risk period for thrombosis, 4 (28.6%) developed a VTE episode. The overall incidence of risk-related VTE was 25% per risk period (95% confidence interval, 6.8-64). In conclusion, the thrombotic risk in otherwise healthy children with severe inherited thrombophilia does not seem to differ from that reported for adults with the same defects. Screening for thrombophilia in children who belong to families with these defects seems justified to identify those who may benefit from thromboprophylaxis during risk periods for thrombosis.

Massive thrombosis in an infant with suspected nephrocalcinosis: case report and literature review

Introduction

Perinatal period is characterized by an increased risk of thrombosis due to low resources and limited compensatory capacity of the coagulation system in early stages of life.

Case report

We report a case of a second pregnancy female infant born at 39 weeks by caesarean section, due to pre-labor rupture of membranes, with body weight of 3,570 γ and Apgar score 10. The pregnancy was complicated by hypothyroidism, uterine myoma, urinary tract infections, and mother's appendectomy at 16 Hbd. At 3 months, the girl was admitted to our hospital due to kidney calcifications, which were incidentally found during ultrasound scan. In laboratory workup, no abnormalities in calcium and phosphate homeostasis were detected. However, in ultrasound scan, linear calcifications along pyramids were visualized in both kidneys. Due to atypical location of nephrocalcinosis, Doppler scan was performed, showing lack of visible blood flow from renal veins to inferior vena cava (IVC), with compensatory flow from renal veins to paravertebral plexuses, and IVC obliteration with a massive calcification in the hepatic section. Magnetic resonance confirmed obliteration of IVC and common iliac veins, segmental dilatation of IVC, and compensatory blood flow from kidneys and lower limbs to paravertebral plexuses. Clinical picture and formation of collateral circulation suggested intrauterine thrombosis. Congenital thrombophilia was excluded in laboratory examination.

Conclusions

The differential diagnosis of calcifications in renal parenchyma (nephrocalcinosis) should include renal vein thrombosis. Massive fetal and perinatal thrombosis can be asymptomatic due to high ability to form collateral circulation at the early stage of life.

Congenital syphilis unusually presenting with prematurity-related severe neonatal morbidities including meconium obstruction: A case report and review of the literature

RATIONALE

Congenital syphilis (CS) can manifest as a variety of clinical presentations according to the severity in symptomatic infants during neonatal period. Preterm neonates with CS may have more clinical evidences of infection and be more severely affected by CS compared with term ones. With increasing survival of markedly premature infants for recent decades, CS may be a challenging problem in those with severe manifestations associated with combined pathophysiologies of CS and prematurity.

PATIENT CONCERNS

A very low birth weight infant at 32 weeks gestation presented with an unusual CS presentation consisting of prematurity-associated severe neonatal morbidities including meconium obstruction, prolonged cholestatic jaundice with elevated liver enzymes, and disseminated intravascular coagulation with a bleeding diathesis, in addition to common or typical manifestations of CS.

DIAGNOSES

Congenital syphilis.

INTERVENTIONS

Therapy consisting of a complete course of parenteral penicillin, blood component therapy, proximal ileotomy with inspissated meconium evacuation and distal loop ileostomy, and other conservative treatments.

OUTCOMES

Resolution with normal gastrointestinal function and improved liver function was observed.

LESSONS

This case suggests that in premature infants CS may manifest as unusual severe neonatal morbidities that may result from combination of syphilitic pathologies and contributors or conditions associated with prematurity including multisystem immaturity.