Effect of Anticoagulant Therapy for 6 Weeks vs 3 Months on Recurrence and Bleeding Events in Patients Younger Than 21 Years of Age With Provoked Venous Thromboembolism: The Kids-DOTT Randomized Clinical Trial

Methods, precision, and analytical sensitivity of a novel low-plasma-volume assay of fibrinolytic capacity utilizing the euglobulin fraction

INTRODUCTION

Fibrinolysis is a critical aspect of the hemostatic system, with assessment of fibrinolytic potential being critical to predict bleeding and clotting risk. We describe the method for a novel low-plasma-volume assay of fibrinolytic capacity utilizing the euglobulin fraction (the "modified mini-euglobulin clot lysis assay [ECLA]"), its analytic sensitivity to alterations in key fibrinolytic substrates/regulators, and its initial applications in acute and convalescent disease cohorts.

METHODS

The modified mini-ECLA requires 50 μL of plasma, a maximal read time of 3 h (with most results available within 60 min), and is entirely performed in a 96-well microplate. Assay measurements were obtained in a variety of commercial control and deficient plasmas representing clinically relevant hypo- and hyperfibrinolytic states, and in three distinct adolescent cohorts with acute or convalescent illness: critically ill, following endotracheal intubation; acute COVID-19-related illness; and ambulatory, 3 months following a venous thromboembolic event.

RESULTS

In 100% and 75% deficient plasmas, hypofibrinolysis for plasminogen-deficient, fibrinolysis for alpha-2-antiplasmin-deficient, and hyperfibrinolysis for plasminogen activator inhibitor-1-deficient plasmas were observed.

CONCLUSION

The modified mini-ECLA Clot Lysis Time Ratio ("CLTR") demonstrated moderate-strength correlations with the Clot Formation and Lysis (CloFAL) assay, is analytically sensitive to altered fibrinolytic states in vitro, and correlates with clinical outcomes in preliminarily-studied patient populations.

Replantation following complete penile amputation: Summary of perioperative experience and treatment strategies

INTRODUCTION

To date, there are only case reports of penile amputation, a rare urological emergency with a low-treatment successful rate, and there are still no advanced, detailed surgical or perioperative treatment plans. Effective treatments for these rare diseases are urgently needed.

METHOD

The researchers summarized the perioperative experience of 20 patients who underwent replantation after complete penile amputation at several hospitals over the past 5 years and shared experience in detail.

RESULTS

Only 1 of the 20 surgeries failed, and both urinary and erectile functions were successfully restored in other cases, indicating that the surgical methods and perioperative treatments summarized by researchers are feasible and highly successful for replantation following complete penile amputation.

CONCLUSION

Researchers have summarized the method and perioperative plan for replantation following penile amputation based on a summary of 20 cases, thereby providing guidance for urologists and andrologists.

Update on management of cerebral venous thrombosis

PURPOSE OF REVIEW

This review intends to systematize the diagnostic and treatment approach to cerebral venous thrombosis (CVT), highlighting key studies that have been recently published.

RECENT FINDINGS

In light of the recent pandemic, new risk factors for CVT have emerged. Contrast-enhanced MRI and susceptibility-weighted imaging have been shown to offer increased sensitivity for detecting cortical vein thrombosis.Dabigatran seems to be as effective and well tolerated as warfarin for long-term anticoagulation. Partial venous recanalization often occurs in patients treated with anticoagulation only, as early as 8 days after treatment onset. For patients with CVT and impending brain herniation, two-thirds of those who undergo decompressive craniectomy survive, with one-third being functionally independent 6 months after diagnosis.

SUMMARY

CVT is an unusual type of cerebrovascular disease that mostly affects women of fertile age. Risk factors should be identified and addressed. Diagnosis relies on confirmation of venous sinus and/or vein thrombosis, usually by CT venography or MRI. Anticoagulation is the cornerstone of treatment. Despite the lack of high-quality evidence, endovascular treatment is often considered in severe cases. Special populations require tailored approaches. About 80% achieve mRS 0-1, but residual symptoms often affect quality of life and the ability to return to work.

Draining Vein Thrombosis of Developmental Venous Anomaly in Sickle Cell Trait Patients: A Case Report and a Literature Review

INTRODUCTION

Cerebral venous sinus thrombosis (CVST) is a rare but serious condition in both adults and children. Risk factors include thrombophilias, dehydration, and certain inherited conditions like sickle cell trait (SCT). We present a case of CVST in a pediatric patient with SCT to highlight key considerations in diagnosis and management.

CASE PRESENTATION

A 14-year-old male with SCT presented with worsening headache and vomiting after prolonged sun exposure and dehydration during athletic camp. Imaging revealed right occipital hemorrhage, hydrocephalus, right CSVT, and bilateral cerebellar developmental venous anomalies. Hypercoagulability testing was normal. Diagnostic evaluation included computed tomography, magnetic resonance imaging, MR venography (MRV), and hypercoagulability testing. The patient was treated with an external ventricular drain, platelet transfusion, and anticoagulation. Management also involved hydration, platelet transfusion, supportive care, and multidisciplinary follow-up. Follow-up MRV showed recanalization.

CONCLUSION

This case highlights SCT as a potential CVST risk factor. Timely recognition, evaluation of precipitants like dehydration, supportive care including anticoagulation, and multidisciplinary management are important. An individualized approach is needed to balance thrombosis recurrence and bleeding risks. Patients with SCT require education on risks and prompt evaluation of neurological symptoms to allow early diagnosis and care of CVST.

Incidence of acute Deep Vein Thrombosis in pediatric and adolescent orthopedic trauma hospitalized patients and effect of rivaroxaban treatment

OBJECTIVE

Deep vein thrombosis (DVT) provoked by orthopedic trauma is increasing in pediatric hospitalized patients. The purpose of our study is to identify the prevalence of acute DVT in pediatric and adolescent orthopedic trauma hospitalized patients and focus on evaluating the anticoagulation strategies and the clinical outcomes after a confirmed acute DVT.

METHODS

Patients (age ≤18 years) with a confirmed acute DVT admitted for orthopedic trauma between September 2017 and December 2023 were included. Patients were classified into the non-anticoagulation (NA), the in-hospital anticoagulation (IHA), and the in-and-out-of-hospital anticoagulation (IOHA) groups based on their anticoagulation regimen. Efficacy outcomes were the venous thromboembolism (VTE) recurrence within 3 months and change in thrombus burden by repeat imaging at 2 weeks after discharge compared with baseline. Safety outcomes were major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) within 3 months.

RESULTS

Of the 11,206 pediatric and adolescent orthopedic trauma inpatients, 94(median age,16 [15, 18] years) were diagnosed with acute DVT, with an incidence of 0.84 %, of which 8(8.5 %) received NA, 41(43.6 %) received IHA, and 45(47.9 %) received IOHA. After the diagnosis of DVT, of patients who received anticoagulation, 97.9 % were treated with rivaroxaban as an oral anticoagulant, and 71.7 % received an LMWH course of ≥5 days before starting rivaroxaban therapy. With a median anticoagulation course of 22(8, 37.3) days, the duration in the IOHA was significantly longer than the IHA (37 days vs. 8 days, p = 0.000). No patients experienced recurrent VTE and MB at 3 months, and 1 received IOHA had a CRNMB event (0 % vs. 0 % vs. 2.2 %, p = 1.000). Thrombus resolution was significantly higher in patients who received anticoagulation therapy (IOHA 91.1 % vs. IHA 80.5 % vs. NA 37.5 %, P = 0.002), and thrombus-no relevant change was significantly lower in patients who received the IOHA strategy compared with the other groups (4.4 % vs. 19.5 % vs. 62.5 %, P = 0.000).

CONCLUSIONS

A rivaroxaban-predominant IOHA strategy significantly reduced the thrombotic burden without increasing the risk of bleeding for the treatment of DVT in adolescents with orthopedic trauma. Duration of anticoagulation therapy <6 weeks appears appropriate for adolescent orthopedic trauma-related DVT.

A Randomized, Controlled Trial of Continuous Heparin Infusion to Prevent Asymptomatic Catheter-related Thrombosis at Discharge in Infants After Cardiac Surgery: The CHIP-CRT Trial

OBJECTIVES

There are conflicting results in preventing catheter-related thrombosis (CRT). Continuing infusion of unfractionated heparin (UFH) was a potential option for CRT. This study was to determine the effect of continuous UFH infusion on asymptomatic CRT at discharge in infants after cardiac surgery.

STUDY DESIGN

This study was a randomized, placebo-controlled, clinical trial at a single center. All infants with central venous catheters after cardiac surgery, below 3 months of age, were eligible. Stratified by CRT, infants were randomly assigned to the UFH group or the normal saline group. UFH was initiated at a speed of 10 to 15 units/kg/h for infants with CRT and 2 to 3 units/kg/h without CRT. The primary outcome was to determine the rate of CRT at discharge. The secondary outcomes included thrombosis 6 months after surgery, adverse events of UFH, and post-thrombotic symptoms.

RESULTS

Due to slow recruitment during the COVID-19 pandemic, this trial was prematurely stopped. Only 35 infants were randomly assigned to the UFH or control groups. There was no statistically significant difference in CRT rate at discharge ( P =0.429) and 6 months after surgery ( P =1.000) between groups. All CRTs except one disappeared at discharge. No thrombosis or post-thrombotic symptom was reported at follow-up evaluation. There was no difference between groups in duration of thrombus ( P =0.088), D dimer ( P =0.412), catheter in situ days ( P =0.281), and post-thrombotic syndrome ( P =1.000), except for activated partial thromboplastin time ( P =0.001).

CONCLUSIONS

With the early stop of this trial and limited data, it is difficult to draw a definitive conclusion about the efficacy of UFH on CRT. Meanwhile, considering the data from 6 months follow-up, in this population, asymptomatic CRT might resolve with no intervention.

Evaluation, analysis, and reporting of medication adherence for clinical trials of anticoagulants in children: guidance from the ISTH SSC Subcommittee on Pediatric and Neonatal Thrombosis and Hemostasis

In response to growing recognition that nonadherence prevents children, adolescents, and young adults from achieving the therapeutic benefits of anticoagulant medication, the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee Subcommittee on Pediatric and Neonatal Thrombosis and Hemostasis convened a working party on medication adherence. The primary aim of this article was to synthesize recommendations from the larger adherence science literature to provide guidance regarding the classification, collection, and interpretation of anticoagulation adherence data. The secondary aim of this article was to evaluate the degree to which trials published from 2013 to 2023 adhered to these guidance recommendations. As less than half of all trials reported on adherence and none included all recommended elements, the proposed International Society on Thrombosis and Haemostasis Scientific and Standardization Committee guidance has the potential to enhance the rigor and reproducibility of pediatric anticoagulant research.

Update in Pediatric Neurocritical Care: What a Neurologist Caring for Critically Ill Children Needs to Know

Currently nearly one-quarter of admissions to pediatric intensive care units (PICUs) worldwide are for neurocritical care diagnoses that are associated with significant morbidity and mortality. Pediatric neurocritical care is a rapidly evolving field with unique challenges due to not only age-related responses to primary neurologic insults and their treatments but also the rarity of pediatric neurocritical care conditions at any given institution. The structure of pediatric neurocritical care services therefore is most commonly a collaborative model where critical care medicine physicians coordinate care and are supported by a multidisciplinary team of pediatric subspecialists, including neurologists. While pediatric neurocritical care lies at the intersection between critical care and the neurosciences, this narrative review focuses on the most common clinical scenarios encountered by pediatric neurologists as consultants in the PICU and synthesizes the recent evidence, best practices, and ongoing research in these cases. We provide an in-depth review of (1) the evaluation and management of abnormal movements (seizures/status epilepticus and status dystonicus); (2) acute weakness and paralysis (focusing on pediatric stroke and select pediatric neuroimmune conditions); (3) neuromonitoring modalities using a pathophysiology-driven approach; (4) neuroprotective strategies for which there is evidence (e.g., pediatric severe traumatic brain injury, post-cardiac arrest care, and ischemic stroke and hemorrhagic stroke); and (5) best practices for neuroprognostication in pediatric traumatic brain injury, cardiac arrest, and disorders of consciousness, with highlights of the 2023 updates on Brain Death/Death by Neurological Criteria. Our review of the current state of pediatric neurocritical care from the viewpoint of what a pediatric neurologist in the PICU needs to know is intended to improve knowledge for providers at the bedside with the goal of better patient care and outcomes.

Anticoagulation in Pediatric Patients

The use of antithrombotic agents is increasing in infants, children and adolescents. The more recent routine inclusion of children in FDA-monitored clinical trials has propelled the rapid accumulation of safety and efficacy data on these agents in pediatric patients. Antithrombotic agents in current use include indirect or antithrombin-dependent anticoagulants, intravenous direct thrombin inhibitors, direct oral anticoagulants (DOACs) targeting thrombin or factor Xa, antiplatelet agents and thrombolytic therapies. Each class of antithrombotic agent has distinct mechanisms of action, clearance routes, half-lives, safety and dosing. Anticoagulant efficacy is dependent upon the specific clinical indication and stability of the pediatric patient. Duration of anticoagulant course is also dependent upon the clinical indication as well as rate of thrombus resolution. This manuscript reviews the mechanism of action, route of administration, route of clearance and plasma half-life for the antithrombotic agents in current use in children. Use of anticoagulation in the context of thrombolytic therapy is discussed.

Real-world experience of direct oral anticoagulant use in a single pediatric center

BACKGROUND

Pediatric venous thromboembolism has increased by 130%-200%, specifically in hospitalized children, and direct oral anticoagulants (DOACs) offer several therapeutic advantages.

METHODS

This study aims to evaluate the real-world epidemiological and outcome data from a retrospective review of pediatric patients treated with DOACs from January 1, 2013 to December 31, 2022. In this single-center, IRB-approved study, 65 patients were identified and analyzed using SPSS statistical software, and a descriptive statistical analysis was conducted.

RESULTS

Of the 65 patients, 37% were on apixaban, 61.5% were on rivaroxaban, and 1.5% were on dabigatran. Per the 2023 ISTH outcome definitions, one (2%) patient had a major bleeding episode, six (9%) had clinically relevant non-major bleeding, three (5%) patients had patient-important heavy menstrual bleeding (HMB), and one (1.5%) patient had minor bleeding. Seven (19%) of 37 postmenarchal patients had evidence of HMB. Six (9.2%) patients had recurrent venous thromboembolism while on a DOAC (one was on apixaban, and five were on rivaroxaban) and were transitioned to other forms of anticoagulation.

CONCLUSION

Thus, bleeding rates after DOAC therapy are comparable to previous DOAC trials, as well as other anticoagulants in pediatrics. HMB is an important outcome measure and should continue to be investigated. This study reports a higher rate of recurrent thrombosis (9.2%) compared to other trials. However, this observation may be attributed to patients who had ongoing risk factors, as well as a longer duration of study follow-up. Additional multicentered outcome studies evaluating DOAC use in children are needed to determine long-term recurrence and HMB risks.

Anticoagulation of pediatric patients with venous thromboembolism in 2023

Venous thromboembolism (VTE) is a rare and heterozygous disease in children. Management of VTE in children is complicated by age-related differences in epidemiology, recurrent VTE and bleeding risk, hemostatic proteins and pharmacokinetics of anticoagulants. Recently, the choice of anticoagulation has expanded to oral factor IIa and Xa inhibitors, which have been authorized for children for treatment of acute VTE and extended secondary prevention. These drugs have several properties that make them extremely suitable for use in children, including oral administration, antithrombin independence, less interactions with food and drugs and no need for monitoring. Unfortunately, the phase 3 studies had many exclusion criteria, and only a few term neonates and infants were included in these studies. Additional real-world data is needed to make evidence-based recommendations in these age and patient groups, as well.

Diagnosis and Management of Cerebral Venous Thrombosis: A Scientific Statement From the American Heart Association

Cerebral venous thrombosis accounts for 0.5% to 3% of all strokes. The most vulnerable populations include young individuals, women of reproductive age, and patients with a prothrombotic state. The clinical presentation of cerebral venous thrombosis is diverse (eg, headaches, seizures), requiring a high level of clinical suspicion. Its diagnosis is based primarily on magnetic resonance imaging/magnetic resonance venography or computed tomography/computed tomographic venography. The clinical course of cerebral venous thrombosis may be difficult to predict. Death or dependence occurs in 10% to 15% of patients despite intensive medical treatment. This scientific statement provides an update of the 2011 American Heart Association scientific statement for the diagnosis and management of cerebral venous thrombosis. Our focus is on advances in the diagnosis and management decisions of patients with suspected cerebral venous thrombosis. We discuss evidence for the use of anticoagulation and endovascular therapies and considerations for craniectomy. We also provide an algorithm to optimize the management of patients with cerebral venous thrombosis and those with progressive neurological deterioration or thrombus propagation despite maximal medical therapy.

Dabigatran for Treatment and Secondary Prevention of Venous Thromboembolism in Pediatric Congenital Heart Disease

BACKGROUND

Congenital heart disease (CHD) is common in children and associated with greater risk of thrombotic complications. Management of these complications with standard-of-care treatment is suboptimal for these children.

METHODS AND RESULTS

The effectiveness and safety of dabigatran were demonstrated in pivotal pediatric studies for the treatment of acute venous thromboembolism (VTE; NCT01895777) and secondary VTE prevention (NCT02197416). We report safety and efficacy outcomes from subgroup analyses of these studies for children with CHD (diagnosed according to local practice) and those without. In NCT01895777, 17/21 (81.0%) and 16/27 (59.3%) patients with CHD (including cyanotic) treated with dabigatran and standard of care, respectively, met the primary end point (complete thrombus resolution, freedom from recurrent VTE, and freedom from VTE-related death; odds ratio [OR], 0.34 [95% CI, 0.08-1.23]). In patients without CHD, 41.0% (n=64) versus 34.9% (n=22) achieved this end point with the respective treatments (OR, 0.77 [95% CI, 0.42-1.41]). Although numerical differences were observed, no heterogeneity in treatment effect of dabigatran on the composite primary end point was detected in patients with and without CHD (interaction P =0.2674). In NCT02197416, recurrent VTE at 12 months occurred in 0/17 patients with CHD versus 3/194 (1.5%) without. No patient with CHD experienced major or clinically relevant nonmajor bleeding events.

CONCLUSIONS

Data on favorable anticoagulant alternatives for the unmet needs of children with CHD are emerging, and our exploratory results suggest that dabigatran could be an appropriate treatment choice, although challenging sample size limitations in pediatric studies require cautious interpretation of findings.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01895777, NCT02197416.

How I treat pediatric venous thromboembolism in the DOAC era

ABSTRACT

The direct oral anticoagulants (DOACs) rivaroxaban and dabigatran are newly licensed for the treatment and prevention of venous thromboembolism (VTE) in children and mark a renaissance in pediatric anticoagulation management. They provide a convenient option over standard-of-care anticoagulants (heparins, fondaparinux, and vitamin K antagonists) because of their oral route of administration, child-friendly formulations, and significant reduction in monitoring. However, limitations related to therapeutic monitoring when needed and the lack of approved reversal agents for DOACs in children raise some safety concerns. There is accumulating experience of safety and efficacy of DOACs in adults for a broad scope of indications; however, the cumulative experience of using DOACs in pediatrics, specifically for those with coexisting chronic illnesses, is sparse. Consequently, clinicians must often rely on their experience for treating VTE and extrapolate from data in adults while using DOACs in children. In this article, the authors share their experience of managing 4 scenarios that hematologists are likely to encounter in their day-to-day practice. Topics addressed include (1) appropriateness of indication; (2) use for special populations of children; (3) considerations for laboratory monitoring; (4) transition between anticoagulants; (5) major drug interactions; (6) perioperative management; and (7) anticoagulation reversal.

The History of Extracorporeal Membrane Oxygenation and the Development of Extracorporeal Membrane Oxygenation Anticoagulation

Extracorporeal membrane oxygenation (ECMO) was first started for humans in early 1970s by Robert Bartlett. Since its inception, there have been numerous challenges with extracorporeal circulation, such as coagulation and platelet activation, followed by consumption of coagulation factors and platelets, and biocompatibility of tubing, pump, and oxygenator. Unfractionated heparin (heparin hereafter) has historically been the defacto anticoagulant until recently. Also, coagulation monitoring was mainly based on bedside activated clotting time and activated partial thromboplastin time. In the past 50 years, the technology of ECMO has advanced tremendously, and thus, the survival rate has improved significantly. The indication for ECMO has also expanded. Among these are clinical conditions such as postcardiopulmonary bypass, sepsis, ECMO cardiopulmonary resuscitation, and even severe coronavirus disease 2019 (COVID-19). Not surprisingly, the number of ECMO cases has increased according to the Extracorporeal Life Support Organization Registry and prolonged ECMO support has become more prevalent. It is not uncommon for patients with COVID-19 to be on ECMO support for more than 1 year until recovery or lung transplant. With that being said, complications of bleeding, thrombosis, clot formation in the circuit, and intravascular hemolysis still remain and continue to be major challenges. Here, several clinical ECMO experts, including the "Father of ECMO"-Dr. Robert Bartlett, describe the history and advances of ECMO.

Venous thromboembolism characteristics, treatment and outcomes in young adults: findings from the Registro Informatizado de Enfermedad TromboEmbólica registry

BACKGROUND

Venous thromboembolism (VTE) is rare in patients aged <21 years. Young adults aged 18 to 21 years are frequently included in adult VTE studies, whereas pediatric VTE studies include patients aged up to either 18 or 21 years. The clinical characteristics of young adult patients with VTE have not been well defined.

OBJECTIVES

We aimed to highlight any unique characteristics or treatment considerations that may apply to young adult patients with VTE.

METHODS

Data from the prospective, international Registro Informatizado de Enfermedad TromboEmbólica registry were used. Patients were stratified into subcohorts according to age. The clinical characteristics, risk factors, management, and outcomes of young adult patients with VTE were compared with those of adolescents aged 12 to 18 years and adults aged >21 years.

RESULTS

Of 104 253 Registro Informatizado de Enfermedad TromboEmbólica patients enrolled until August 2022, 234 were adolescents and 884 were young adults. Less cases of pulmonary embolism were reported in adolescents (P < .001). Estrogen use was a common risk factor, more prevalent in adolescents and young adults (P < .001), whereas active cancer and immobilization were uncommon in both. Most patients were initially treated with low-molecular-weight heparin. VTE recurrence, major bleeding, and all-cause mortality rates were comparably low among adolescents and young adults. None of the patients aged <21 years died from VTE recurrence.

CONCLUSION

Young adults have some distinctive VTE risk factors. While VTE presentation may be similar among young adults and older patients, the outcomes of patients aged <21 years are more favorable.

Anticoagulant treatment for pediatric splanchnic vein thrombosis: a systematic review and meta-analysis

BACKGROUND

The clinical characteristics of splanchnic vein thrombosis (SVT) in pediatric patients and its optimal treatment strategies are unknown.

OBJECTIVES

This study aimed to assess the effectiveness and safety of anticoagulant therapy for pediatric SVT.

METHODS

MEDLINE and EMBASE databases were searched up to December 2021. We included observational and interventional studies that enrolled pediatric patients with SVT and reported anticoagulant treatment and outcomes, including rates of vessel recanalization, SVT extension, venous thromboembolism (VTE) recurrence, major bleeding, and mortality. Pooled proportions of vessel recanalization were calculated with their 95% CI.

RESULTS

A total of 506 pediatric patients (aged 0-18 years) across 17 observational studies were included. The majority of patients had portal vein thrombosis (n = 308, 60.8%) or Budd-Chiari syndrome (n = 175, 34.6%). Most events were triggered by transient provoking factors. Anticoagulation (heparins and vitamin K antagonists) was prescribed in 217 (42.9%) patients, and 148 (29.2%) patients underwent vascular interventions. The overall pooled proportions of vessel recanalization were 55.3% (95% CI, 34.1%-74.7%; I2 = 74.0%) among anticoagulated patients and 29.4% (95% CI, 2.6%-86.6%; I2 = 49.0%) among non-anticoagulated patients. SVT extension, major bleeding, VTE recurrence, and mortality rates were 8.9%, 3.8%, 3.5%, and 10.0%, respectively, in anticoagulated patients and 2.8%, 1.4%, 0%, and 50.3%, respectively, in non-anticoagulated patients.

CONCLUSION

In pediatric SVT, anticoagulation appears to be associated with moderate recanalization rates and a low risk of major bleeding. VTE recurrence is low and comparable to that reported in pediatric patients with other types of provoked VTE.

Lung abscess as a complication of Lemierre Syndrome in adolescents: a single center case reports and review of the literature

BACKGROUND

Fusobacterium necrophorum is an anaerobic, gram-negative, non-motile, filamentous, non-spore forming bacillus found in the oral cavity, gastrointestinal tract, and female genital tract, responsible of a rare disease named Lemierre Syndrome, characterized by septic thrombophlebitis of the internal jugular vein, which mainly affects previously healthy adolescents and young adults; some risk factors are reported, as smoking or primary viral or bacterial infection leading to the disruption of mucosa. The syndrome originates commonly from an upper respiratory infection such as pharyngotonsillitis, acute otitis media, cervical lymphadenitis, sinusitis, or odontogenic abscess, and may result in multiorgan metastasis, more frequently leading to pulmonary complications, especially lung abscesses.

CASE PRESENTATION

We describe two cases of adolescents with atypical Lemierre Syndrome evaluated in a tertiary care center, one with a confirmed infection by Fusobacterium necrophorum and one with a presumptive diagnosis based on clinical features, who developed lung abscesses needing a prolonged antibiotic course and hospitalization. Of interest, both were user of electronic cigarette, configuring a possible new risk factor. The proper diagnosis of Lemierre Syndrome is often difficult to establish, so a high degree of suspicion is needed, especially in the case of lung abscesses in otherwise healthy adolescents.

CONCLUSION

The current study will contribute to providing insight into Lemierre Syndrome clinical presentation and management in adolescents, promoting awareness for a rare but potentially fatal disease. Moreover, it suggests a possible relationship between Lemierre syndrome and the use of electronic cigarette, that should be investigated by future studies.

Biomarkers in pediatric venous thromboembolism: a systematic review of the literature

BACKGROUND

Accurate prediction of the individual risk of venous thromboembolism (VTE) remains suboptimal in children, and biomarkers are currently not used to stratify the risk of VTE in children.

OBJECTIVES

This study aimed to assess which biological or radiological biomarkers may predict VTE or VTE complications in children.

PATIENTS/METHODS

A literature search was performed for peer-reviewed publications (1990-2022). We included studies addressing the use of biomarkers for patients aged 29 days to 18 years to predict VTE or its complications, including but not limited to TE-related death, VTE recurrence, or postthrombotic syndrome. Given the heterogeneity of the study designs, populations, and outcomes, no quantitative data synthesis was performed.

RESULTS

Forty studies were included, totaling 10,987 participants (median age: 4.7 years). Reports were often lacking critical methodological data, including blood collection method (68% of studies) and timepoints, laboratory testing technique (41%), or primary outcome definition (20%). Forty-six individual biomarkers were assessed for VTE prediction (32 studies, 9525 participants), including d-dimers, fibrinogen, platelet count, white blood cell count, and factor VIII. Albumin, C-reactive protein, d-dimers, factor VIII, and thrombin-antithrombin levels showed promising results for VTE prediction. In 9 studies (1606 participants), no biomarker was consistently predictive of postthrombotic syndrome, VTE persistence, or VTE recurrence in children.

CONCLUSIONS

Several candidate biomarkers were promising in the prediction of VTE in children. Still, discrepancies between different studies and the high risk of bias from the current literature prevent their widespread use in the clinical setting. Further prospective research in various pediatric subpopulations is required.

Updated guidance for efficacy and safety outcomes for clinical trials in venous thromboembolism in children: communication from the ISTH SSC Subcommittee on Pediatric and Neonatal Thrombosis and Hemostasis

Despite the growing number of pediatric antithrombotic clinical trials, standardized safety and efficacy outcome definitions for pediatric venous thromboembolism (VTE) clinical trials have not been updated since 2011. Many recent trials have adapted the recommended definitions, leading to heterogeneity in outcomes and limiting our ability to compare studies. The International Society on Thrombosis and Haemostasis Scientific and Standardization Subcommittee (SSC) on Pediatric and Neonatal Thrombosis and Hemostasis organized a Task Force to update the efficacy and safety outcome definitions for pediatric VTE clinical trials. The outcome definitions used in the recent pediatric antithrombotic trials, definitions recommended for adult studies, and regulatory guidelines were summarized and reviewed by the Task Force as the basis for this updated guidance. Major updates to the efficacy outcomes include the removal of VTE-related mortality as a part of a composite primary outcome and explicit inclusion of all deep venous anatomic sites. Safety outcomes were updated to include a new bleeding severity category: patient important bleeding, no intervention, which encompasses bleeding for which a patient seeks care but there is no change in management. Menstrual bleeding can now be included in any bleeding category when the criteria are met. We hope that these updated outcome definitions will allow the investigators to focus on clinically relevant and patient-important outcomes and provide standardization to facilitate continued high-quality evidence for the use of antithrombotic therapies in children.

Between Scylla and Charybdis: thrombosis in children with hemophilia

Thromboembolism is an infrequent complication in children with hemophilia that has been traditionally associated with the presence of a central venous access device. Novel rebalancing agents have shown promising results as prophylactic therapies to minimize the risk of bleeding but both thromboembolism and thrombotic microangiopathy have been reported as complications. The management of thrombosis in children with hemophilia is particularly challenging given the inherent risk of bleeding. In this paper, we present clinical vignettes to review the literature, highlight challenges, and describe our approach to managing thromboembolism in children with hemophilia.

Management of venous thromboembolism in pediatric patients: Quality assessment of clinical practice guidelines and variations in recommendations

INTRODUCTION

We performed a quality assessment and comparison of clinical practice guidelines (CPGs) for the prevention and treatment of venous thromboembolism (VTE) in pediatric patients and to provide a clinical reference.

MATERIALS AND METHODS

Electronic databases, guideline development organizations, and professional societies were searched to identify CPGs for VTE in pediatric patients between January 1, 2012, and April 7, 2022. The Appraisal of Guidelines Research & Evaluation (AGREE) II instrument was used to evaluate quality. Recommendations for preventing and treating VTE in pediatric patients were extracted via descriptive synthesis.

RESULTS

Six CPGs were included. The median scores (interquartile range [IQR]) for each AGREE II domain were as follows: scope and purpose, 88.89 % (IQR: 8.33 %); stakeholder involvement, 88.89 % (25 %); rigor of development, 67.71 % (24.47 %); clarity and presentation, 88.89 % (0 %); applicability, 50 % (42.71 %); and editorial independence, 66.67 % (50.00 %). In total, 268 key recommendations were extracted, and traditional anticoagulants (heparin and warfarin) remain the standard treatment. However, in recent years direct oral anticoagulants (DOACs) have shown similar efficacy and safety results for the treatment of VTE in children to those reported in adults; therefore, this practice is recommended in recent guidelines.

CONCLUSIONS

Variability exists in the development and reporting of CPGs for VTE in pediatric patients. There may be changes to the recommendations for the prevention and treatment of VTE in pediatrics in the future due to the efficacy of DOACs in children, and recommendations should be revised periodically as new evidence emerges.

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.

Just DOAC: Use of direct-acting oral anticoagulants in pediatrics

PURPOSE

The aim of this article is to provide an overview of the current literature for direct-acting oral anticoagulant (DOAC) use in pediatric patients and summarize ongoing trials.

SUMMARY

In treatment of venous thromboembolism (VTE) in pediatric patients, evidence supports use of both dabigatran and rivaroxaban. Dabigatran has been shown to be noninferior to standard of care (SOC) in terms of efficacy, with similar bleeding rates. Similarly, treatment with rivaroxaban in children with acute VTE resulted in a low recurrence risk and reduced thrombotic burden, without increased risk of bleeding, compared to SOC. Treatment of pediatric cerebral venous thrombosis as well as central venous catheter-related VTE with rivaroxaban appeared to be both safe and efficacious and similar to that with SOC. Dabigatran also has a favorable safety profile for prevention of VTE, and rivaroxaban has a favorable safety profile for VTE prevention in children with congenital heart disease. Many studies with several different DOACs are ongoing to evaluate both safety and efficacy in unique patient populations, as well as VTE prevention.

CONCLUSION

The literature regarding pediatric VTE treatment and prophylaxis is growing, but the need for evidence-based pediatric guidelines remains. Additional long-term, postauthorization studies are warranted to further elucidate safety and efficacy in clinical scenarios excluded in clinical trials. Additional data on safety, efficacy, and dosing strategies for reversal agents are also necessary, especially as the use of DOACs becomes more common in the pediatric population.

Cerebral Sinovenous Thrombosis in Infants and Children: A Practical Approach to Management

Cerebral sinovenous thrombosis (CSVT) is a rare, yet potentially devastating disorder, associated with acute complications and long-term neurologic sequelae. Consensus-based international pediatric CSVT treatment guidelines emphasize early clinical-radiologic recognition and prompt consideration for anticoagulation therapy. However, lack of clinical trials has precluded evidence-based patient selection, anticoagulant choice, optimal monitoring parameters and treatment duration. Consequently, uncertainties and controversies persist regarding anticoagulation practices in pediatric CSVT. This review focuses on commonly encountered issues that continue to pose questions and raise debates regarding anticoagulation therapy among pediatric neurologists and hematologists.

Hemostatic and thrombotic disorders in the pediatric patient

This review focuses on significant advances in the field of pediatric hemostasis and thrombosis, with a focus on published studies within the past decade. The evaluation and management of patients with excessive bleeding remain cornerstones of consultative hematology. We will describe the development of validated bleeding assessment tools relevant to pediatric practice, laboratory advances in the evaluation of von Willebrand disease, and a shift in clinical practice regarding the interpretation of normal coagulation studies in patients with significant bleeding phenotypes. There have also been critical advances in the management of hemostatic disorders. This review highlights new treatment paradigms in hemophilia and the rise of multidisciplinary medical homes for women living with bleeding disorders. Given the continued increase in the incidence of thrombosis, particularly in the hospital setting, a full call to arms against pediatric venous thromboembolism is now essential. We will describe recently completed clinical trials of direct oral anticoagulants in children and adolescents and ongoing work to elucidate the appropriate duration of therapy for children with provoked thrombosis. Recent work regarding the prevention of pediatric venous thromboembolism is highlighted, including studies of thromboprophylaxis and the development of risk prediction models for hospital-acquired thrombosis. Finally, we review advances in our understanding of thrombotic sequelae and the need for continued refinement of our evaluation tools. Despite the significant advances in pediatric hemostasis and thrombosis over the past decade, many unanswered questions remain for the next generation of investigators.

A phase 2 pharmacodynamic dose-finding, safety, and efficacy study of dalteparin for pediatric venous thromboembolism treatment in children with and without cancer

Data from registrational trials of pediatric venous thromboembolism (VTE) treatment are sparse, especially among cancer patients. We conducted a prospective, multicenter, open-label trial (NCT00952380) on dose-finding, safety, and efficacy (measured by 90-day risks of clinically relevant bleeding [CRB] and symptomatic recurrent VTE [srVTE]) of twice-daily subcutaneous dalteparin for acute VTE treatment in patients ≤18 years old. Among 38 patients (cancer, n = 26; noncancer, n = 12), median dalteparin dose requirements per kilogram varied with age but not cancer status. Risks of CRB and srVTE were <4% in cancer and noncancer subgroups. Dalteparin is an important FDA-approved treatment for pediatric VTE, particularly with cancer.

Results of an international survey on adherence with anticoagulation in children, adolescents, and young adults: Communication from the ISTH SSC Subcommittee on Pediatric and Neonatal Thrombosis and Hemostasis

BACKGROUND

The ISTH Scientific and Standardization Committee (SSC) Subcommittee on Pediatric/Neonatal Thrombosis and Hemostasis convened a working group on medication adherence to begin to understand the current state of clinical practice to inform priority areas for efforts to improve adherence for children, and adolescents and young adults (AYA) prescribed anticoagulants.

OBJECTIVES

We sought to survey an international group of clinicians involved in anticoagulation management in children and/or AYA about perceptions of medication on health outcomes, clinical practice related to medication adherence, and barriers to assessing and improving medication adherence.

METHODS

Clinicians involved in anticoagulation management in children and/or AYA were surveyed via REDCap® . Descriptive statistics were used to summarize demographic and clinical characteristics and responses to multiple choice and Likert-type questions. Free-text answers were coded based on the Behaviour Change Technique Taxonomy and the Expert Recommendations for Implement Change project.

RESULTS AND CONCLUSIONS

There were 200 participants, 90% of whom were pediatric hematology/oncology physicians. Based on the results, which demonstrate that clinicians are concerned about impact of poor medication adherence and have limited resources to identify and improve adherence, the working group has identified next steps to further understand impact of medication adherence on anticoagulation-related health outcomes, address the need for validated measures to assess medication adherence for all anticoagulants prescribed to this population, and develop an intervention and implementation research agenda to improve outcomes.

Central venous catheter-associated deep vein thrombosis in critically ill pediatric patients: risk factors, prevention, and treatment

PURPOSE OF REVIEW

Central venous catheter (CVC) placement and ICU admission are the two most important risk factors for pediatric deep vein thrombosis. The optimal prevention and treatment strategies for CVC-associated deep vein thrombosis (CADVT) are unclear, but recently, seminal studies have been published. This review aims to summarize the recent literature on CADVT in critically ill children.

RECENT FINDINGS

Recent publications focused on three themes: risk factors, prevention, and treatment of CADVT. Newly identified risk factors for CADVT relate to Virchow's triad of hemostasis, blood vessel injury, and hypercoagulability. New risk prediction models have moderately good accuracy in predicting CADVT. Though previous data on pharmacologic CADVT prophylaxis was equivocal, recent studies indicate that low-molecular-weight heparin may be effective in preventing CADVT, particularly in critically ill children. Finally, new studies suggest that direct oral anticoagulants and shorter treatment times are noninferior to traditional agents and treatment durations in the treatment of CADVT.

SUMMARY

Recent research suggests new ways to accurately identify children at high risk of CADVT, effectively prevent CADVT, and optimize CADVT treatment. Future research should focus on understanding the pathobiology of CADVT formation, prevention, and treatment in critically ill children.

Thrombotic events in critically ill children with coronavirus disease 2019 or multisystem inflammatory syndrome in children

PURPOSE OF REVIEW

To provide an update regarding what is known about thrombotic events and thromboprophylaxis in critically ill children with SARS-CoV-2 infection.

RECENT FINDINGS

Pediatric patients with SARS-CoV-2 generally have mild illness; however, intensive care is required in about 20-30% of hospitalized children with COVID-19 and an even higher proportion in those with MIS-C. Increased rates of thrombosis have been observed in adults hospitalized with COVID-19, and clinical trials have attempted to optimize thromboprophylaxis. There is significant variability in the estimated incidence of thrombosis in pediatric patients (0-27%) because of variation in patient populations and study design. Multiple studies demonstrate an increased rate of thrombosis compared with baseline in hospitalized pediatric patients. Few studies have evaluated risk factors for thrombosis, but critical illness, older age, and other known thrombosis risk factors appear to increase the risk. Thromboprophylaxis strategies are inconsistent, with little evidence of efficacy but few reports of major bleeding.

SUMMARY

Critically ill children with SARS-CoV-2-related illnesses are at increased risk of thrombosis. Thromboprophylaxis should be considered in select patients with COVID-19 or MIS-C, though the optimal strategy is not yet known. More data is required to guide practice to prevent thrombosis in this population.

Du ration of Anticoagulant Therapy for Pediatric Venous Thromboembolism

According to this study: Among patients younger than 21 years of age who have provoked venous thromboembolism, anticoagulant therapy for six weeks compared with three months met noninferiority criteria based on the trade-off between recurrent venous thromboembolism risk and bleeding risk.

Iron deficiency anemia and thrombosis risk in children-revisiting an old hypothesis

Iron deficiency anemia has a high prevalence in children and has repeatedly been implicated as a risk factor for arterial and venous thrombosis. As an effective therapy for iron deficiency anemia is available, understanding the association between this form of anemia and the potentially severe thrombosis phenotype is of major clinical interest. Recent findings shed light on pathophysiology of hypercoagulability resulting from iron-restricted erythropoiesis. Specifically, an animal model of induced iron deficiency allowed identifying multiple mechanisms, by which iron deficiency anemia results in increased thrombus formation and thrombus progression both in arterial and venous thrombosis. These findings complement and support conclusions derived from clinical data. The purpose of this mini review is to summarize current evidence on the association of iron deficiency anemia and thrombosis. We want to increase the awareness of iron deficiency as a risk factor for thrombosis in the pediatric population. We discuss how novel pathophysiological concepts can be translated into the clinical settings and suggest clinical studies on prevention and treatment strategies in high-risk patient groups.

Challenges in Management of VTE in Children With Cancer: Risk Factors and Treatment Options

Venous thromboembolism (VTE) occurs in 2.1 to up to 50% of children with cancer and contributes to long term morbidity as well as early mortality in this population. Pediatric patients with malignancy are predisposed to VTE due to the prothrombotic nature of cancer and its associated coagulopathies as well as chemotherapeutic agents, use of central venous catheters, surgery, radiotherapy, and concomitant thrombophilia. Management of thrombosis in this population is challenging due to concomitant thrombocytopenia, associated bleeding risks, concurrent co-morbidities, and toxicities of therapy. The aim of this paper is to highlight clinically relevant issues and management dilemmas using clinical vignettes. We review the clinical significance of asymptomatic and symptomatic thrombosis, examine the various options for asparaginase-associated thrombosis, address the role and controversies of direct oral anticoagulants, and describe our approach to managing anticoagulation therapy in the context of chemotherapy-induced thrombocytopenia.

Systemic Catheter-Related Venous Thromboembolism in Children: Data From the Italian Registry of Pediatric Thrombosis

BACKGROUND

Central venous catheters (CVCs) represent one of the main risk factors for venous thrombotic events (VTEs) in children.

METHODS

We studied the Italian Registry of Pediatric Thrombosis (RITI) with regard to systemic radiologically confirmed CVC-related VTEs (CVC-VTEs) occurred during 6.5 years in children aged 29 days to 18 years.

RESULTS

A total of 78 CVC-VTEs were included, which occurred in 76 patients (40/76, 53% males). CVC-VTEs comprised 67 non-cardiac VTEs (86%) and 11 intracardiac thrombotic events (ICTEs) (14%); the median age at onset was 19 and 17 months, respectively. The most frequent reason for CVC insertion was supportive therapy. The catheters were placed percutaneously in 85% of cases (56/66) and surgically in the remaining 15% (10/66). Peripherally inserted central catheters (PICCs) were used in 47% (31/66) cases, partially implanted catheters in 42% (28/66), non-implantable catheters in 7% (5/66), and totally implanted catheters (Port) in 2% (1/66). CVC-VTEs were symptomatic in 77% of cases (60/78), while in the remaining 23%, they were incidentally detected on the imaging performed for the underlying condition. The median time between CVC insertion and the onset of symptoms was 10 days in non-cardiac VTEs and 39 days in ICTEs. Doppler ultrasound was the diagnostic technique most frequently used. The venous compartment most frequently affected was the veins of the lower extremities (52%, 43/73). Anti-thrombotic treatment was administered in 96% of CVC-VTEs (75/78). About 2.6% (2/76) of patients experienced a second thrombotic event. At discharge, post-thrombotic syndrome was reported in 13.5% (5/37) events with available data, CVC replacement in 10.8% (4/47), and ischemic necrosis with toe finger amputation in 2.7% (1/37). Three patients died due to an underlying condition; no CVC-VTE-related deaths were reported.

CONCLUSIONS

We have carried out a registry-based study on CVC-VTEs in the children in Italy, providing the data that may help improve the detection and management of this CVC-related complication.