Venous Thromboembolism in Children: From Diagnosis to Management

Selective iliofemoral stent placement for complex pediatric cases: a decade of institutional experience

BACKGROUND

Pediatric iliofemoral venous thromboembolism that is resistant to conventional treatments poses significant management challenges. Stent placement represents a potentially underutilized strategy in children when stenosis or thrombosis persists intraprocedurally or recurs postoperatively, despite treatments such as venoplasty, lysis, and thrombectomy.

OBJECTIVE

This study aims to report our institutional experience with iliofemoral stenting in 17 pediatric patients with recurrent iliofemoral venous thromboembolism or stenosis.

MATERIALS AND METHODS

We performed an IRB-approved retrospective review of pediatric patients (<18 years of age) who underwent iliofemoral venous stenting for recurrent stenosis or thrombosis between January 2012 and December 2022 at a single tertiary care institution. Patient demographics, risk factors for venous thromboembolism, presenting symptoms, and procedural characteristics were recorded. The primary outcome was stent patency rates at interval imaging follow-up.

RESULTS

Seventeen patients with mean age of 14.6 years (range 7-17) and mean BMI of 27.7 were stented during the study period. Sixteen of 17 patients presented with evidence of May-Thurner anatomy. 14/17 patients presented with acute iliofemoral venous thromboembolism, 2/17 with chronic venous thromboembolism, and 1/17 with left lower extremity swelling without thrombosis. Seventy-three total angiographic procedures were performed, which included angioplasty, lysis, and thrombectomy, and 23 stent placements. Patients underwent an average of 3 procedures (range 1-9) over a mean of 2.8 months (range 0-17 months) prior to undergoing stent placement. Stents were deployed successfully in all patients. The median follow-up was 18 months (range, 1-77 months). Primary and secondary patency rates were 13/17 (76%) and 14/14 (100%) at 12 months and 12/17 (71%) and 14/14 (100%) at 24 months, respectively.

CONCLUSION

In our experience of 17 patients, stent placement appears to be a durable option for children with iliofemoral venous thromboembolism following failure to establish vessel patency or development of recurrent thrombosis/stenosis postoperatively.

Thromboembolism in Children

OBJECTIVE

To study pediatric patients who were diagnosed with thrombosis between January 2009 and March 2020.

METHODS

Patients were evaluated with respect to thrombophilic risk factors, localization of the thrombus, response to treatment, and recurrence rates during the last 11 y.

RESULTS

Among 84 patients, 59 (70%) had venous thrombosis and 20 (24%) had arterial thrombosis. The number of documented thrombosis amongst hospitalized children in authors' hospital has increased over the years. It has been observed that the annual incidence of thromboembolism has increased after 2014. Thirteen patients were recorded between 2009 and 2014 and 71 patients between 2015 and 2020 (until March 2020). Exact thrombosis localization could not be detected in 5 patients. The median age of patients was 8 ± 5.95 (range 0-18). Fourteen children (16.9%) had a history of familial thrombosis. Genetic and/or acquired risk factors were detected in 81 (96.4%) of the patients. Overall, 64 patients (76.1%) had acquired risk factors such as infection (20.2%), catheterization (13.1%), liver disease (11.9%), mastoiditis (8.3%), liver transplantation (6%), hypoxic-ischemic encephalopathy (4.8%), dehydration (3.6%), trauma (3.6%) and cancer (2.4%). As genetic risk factors, the most common genetic mutations were PAI-1 4G>5G, MTHFR C677T, and MTHFR A1298C mutations. Twenty-eight (41.2%) patients had at least one genetic thrombophilic mutation. At least one homozygous mutation in 37 patients (44%) and at least one heterozygous mutation in 55 patients (65.4%) were detected.

CONCLUSIONS

The annual incidence of thrombosis has increased over the years. Genetic predisposition and acquired risk factors play an important role in etiology, treatment, and follow-up in children with thromboembolism. Especially, genetic predisposition is common. Thrombophilic risk factors should be investigated and optimal therapeutic and prophylactic measures should be promptly taken in children with thrombosis.

Vascular complications in craniopharyngioma-resected paediatric patients: a single-center experience

Background

Craniopharyngioma (CP), although slow growing and histologically benign, has high morbidity, mostly related to hypothalamus-pituitary dysfunction and electrolyte imbalance. Increased risk of vascular complications has been described. However, data are still poor, especially in the paediatric population. The aim of our study was to evaluate the occurrence, timing, and predisposing factors of deep venous thrombosis (DVT) and other vascular alterations in neurosurgical paediatric CP patients.

Materials and Methods

In a single-centre, retrospective study, we investigated 19 CP patients (11 males, 8 females, mean age 10.5 ± 4.3 years), who underwent neurosurgery between December 2016 and August 2022, referred to Meyer Children's Hospital IRCCS in Florence.

Results

Five patients (26.3%) presented vascular events, which all occurred in connection with sodium imbalances. Three DVT (two with associated pulmonary embolism, in one case leading to death) developed in the post-operative period, most frequently at 7-10 days. Elevated D-dimers, a reduced partial activated thrombin time and a prolonged C-reactive protein increase were highly related to thrombotic vascular events. One case of posterior cerebral artery pseudoaneurysm was described soon after neurosurgery, requiring vascular stenting. Superficial vein thrombophlebitis was a late complication in one patient with other predisposing factors.

Conclusion

CP patients undergoing neurosurgery are at risk of developing DVT and vascular alterations, thus careful follow-up is mandatory. In our study, we found that the phase of transition from central diabetes insipidus to a syndrome of inappropriate antidiuretic hormone secretion may be a period of significant risk for DVT occurrence. Careful vascular follow-up is mandatory in CP-operated patients.

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.

Factors Associated with Hospital Length of Stay among VTE Cases: Insights from the i-RegVed Registry

INTRODUCTION

Venous thromboembolism (VTE) is a multifactorial condition and one of the leading causes of mortality and disability. The present study explores the factors associated with hospitalization duration among different types of venous thromboembolism diagnoses, such as deep vein thrombosis (DVT), pulmonary embolism (PE), and other forms of thrombosis.

METHODS

The data included participants with VTE admitted to 13 hospitals within pan-India from June 2022 to December 2023 to the i-RegVed registry, where socio-demographic data, clinical history, and various factors associated with hospital length of stay (LOS) were included for analyses. Multilinear regression was performed to explore the factors associated with hospital LOS among VTE conditions such as DVT, PE, forms of thrombosis other than PE and DVT, and all VTE diagnoses.

RESULTS

A total of 633 participants were included in the study, with 55% being males, and 28.9% being homemakers. Longer hospital LOS was significantly associated with age (β = -.09, P < .05), sex (β = 3.21, P < .05), and non-communicable diseases (β = 3.51, P < .05) among participants with DVT and among participants with at least one of the VTE diagnoses, age (β = -.12, P < .001) and anticoagulant use (β = -2.49, P < .05) was significantly associated.

CONCLUSION

The findings provide insights into the factors influencing hospital outcomes among participants with different types of VTE, highlighting the importance of age and comorbidities in predicting the hospital LOS.

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.

Questions around a case of in utero thrombosis in a premature child, concerning the management of anticoagulant treatments

We report the case of a preterm infant presenting a thrombosis, discovered on ultrasound at 22 weeks of gestational age and confirmed at birth following additional examinations. We describe the anticoagulant treatment of this patient by intravenous enoxaparin, tinzaparin and rivaroxaban, from questioning to practice.

Long term use of eltrombopag in children with chronic immune thrombocytopenia: extended real life retrospective multicenter experience of the Italian Association of Pediatric Hematology and Oncology

Background

The present multicenter retrospective study on eltrombopag administration in Italian children with chronic ITP aims to extend follow-up of our previous study.

Materials and methods

This retrospective multicenter study was conducted in 17 centers affiliated to the Italian Association of Pediatric Hematology and Oncology (AIEOP). Patients were classified into three subgroups: group 1 included patients who discontinued treatment due to a stable platelet count; group 2 included patients who discontinued treatment due to ineffectiveness; group 3 included patients who did not permanently discontinue treatment.

Results

56 patients were eligible for analysis. The median duration of eltrombopag treatment was 40 months (7-71 months). Twenty patients (36%) discontinued permanently eltrombopag. The reasons of permanent discontinuation were adverse effects (n = 1), inefficacy (n = 10), stable platelet count (n = 9). All patients of group 1 maintained a durable response without additional treatments after eltrombopag discontinuation. We found that patients of group 2 were on treatment for less time (median treatment time: 13.5 months, min: 6.0 - max: 56.0) than patients of group 1 (median treatment time: 34 months, min: 16.0 - max: 62.0) (p < 0.05). Patients of group 2 mostly did not achieve a stable platelet count in the first 6 months of treatment and underwent concomitant therapies during follow-up respect of group 1 and group 3 (p < 0.01).

Conclusion

Our study found that the benefits of eltrombopag treatment, in terms of platelet count improvement and use of additional therapies, are identifiable from the first 6 months of treatment.

Dabigatran Etexilate: A Review in Pediatric Venous Thromboembolism

Although rare in children, venous thromboembolism (VTE) is markedly more likely in hospitalized patients, particularly with the use of central venous access devices. Dabigatran etexilate (Pradaxa^®) is one of the first direct non-vitamin K antagonist oral anticoagulants (DOAC) approved for use in pediatric patients. It is approved in the EU and USA for the treatment of VTE in patients who have been treated with a parenteral anticoagulant for ≥ 5 days, and for the prevention of recurrent VTE. In an open-label, phase 2b/3 clinical trial in pediatric patients with acute VTE treated for ≈ 3 months, dabigatran etexilate was non-inferior to standard of care (SOC) treatment for the primary composite endpoint of complete thrombus resolution, freedom from recurrent VTE and VTE-related death. In a single-arm phase 3 safety study, few patients experienced recurrent VTE with ≤ 12 months of anticoagulation with dabigatran etexilate. Dabigatran etexilate was generally well tolerated in both studies; bleeding events were mostly minor and, in the phase 2b/3 study, occurred at a similar incidence to SOC. Although further data will be useful, dabigatran etexilate is a valuable and convenient treatment option in pediatric VTE.

Risk of venous thromboembolism in children and adolescents with inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND

A two- to three-fold increased risk of venous thrombotic events (VTE) has been demonstrated in patients with inflammatory bowel disease (IBD) compared to the general population, but less is known about the risk of VTE in child- and pediatric-onset IBD. In recent years, several studies have reported the rising incidence rate of VTE in juvenile patients with IBD, and the related risk factors have been explored.

AIM

To evaluate the risk of VTE in children and adolescents with IBD.

METHODS

Articles published up to April 2021 were retrieved from PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI, and WANFANG. Data from observational studies and clinical work were extracted. The outcome was the occurrence of VTE according to the type of IBD. The available odds ratio (OR) and the corresponding 95% confidence interval (CI) were extracted to compare the outcomes. Effect size (P), odds ratio (OR), and 95%CI were used to assess the association between VTE risk and IBD disease. Subgroup analyses stratified by subtypes of VTE and IBD were performed.

RESULTS

Twelve studies (7450272 IBD patients) were included in the meta-analysis. Child and adolescent IBD patients showed increased VTE risk (P = 0.02, 95%CI: 0.01-0.03). Subgroup analyses stratified by IBD (ulcerative colitis (UC): P = 0.05, 95%CI: 0.03-0.06; Crohn’s disease (CD): P = 0.02, 95%CI: 0.00-0.04) and VTE subtypes (portal vein thrombosis: P = 0.04, 95%CI: 0.02-0.06; deep vein thrombosis: P = 0.03, 95%CI: 0.01-0.05; central venous catheter-related thrombosis: P = 0.23, 95%CI: 0.00-0.46; thromboembolic events: P = 0.02, 95%CI: 0.01-0.03) revealed a significant correlation between VTE risk and IBD. Patients with IBD were more susceptible to VTE risk than those without IBD (OR = 2.99, 95%CI: 1.45-6.18). The funnel plot was asymmetric, suggesting the presence of significant publication bias. Pediatric and adolescent IBD patients have an increased VTE risk. UC and CD patients exhibited a high risk of VTE. The risk of VTE subtypes was increased in IBD patients.

CONCLUSION

The current meta-analysis showed that the incidence and risk of VTE are significantly increased in pediatric and adolescent IBD patients. Thus, IBD might be a risk factor for VTE in children and young adults. High-quality prospective cohort studies are necessary to confirm these findings.

Real-World Anticoagulant Use and Incidence of Venous Thromboembolism and Major Bleeding in Children

PURPOSE

Children generally have a lower risk of venous thromboembolism (VTE) than adults, but those with acute and chronic conditions requiring hospitalization and surgical procedures are at increased risk. Anticoagulant use in children has not been systematically studied, and limited data exist. This study aimed to provide data on the conditions associated with use of anticoagulants, the type of anticoagulant used in children, and the incidence of thromboembolism and major bleeding events reported in this population.

METHODS

To increase understanding of the use of anticoagulant therapies in children with at-risk conditions, 3 health claims databases in the United States were analyzed to describe the characteristics of use of heparins, warfarin, and direct oral anticoagulants (DOACs). Cumulative drug exposure was determined for continuous exposure, defined as >30 days. Unadjusted event rates of VTE and major bleeding after exposure to these therapies were reported. The data were presented descriptively and are not intended for comparison or to imply any causation.

FINDINGS

Anticoagulants were infrequently used in the pediatric population, including at any time point after Fontan surgery for congenital heart disease. Heparins were used most frequently in the population overall and especially for patients aged <12 years. DOACs were used least often and primarily for patients ages 12 to <18 years. Among pediatric patients exposed to anticoagulants, unadjusted incidence rates of VTE per 1000 person-years of exposure ranged from 30.8 to 34.0 for all DOACs, 21.6 to 46.2 for warfarin, and 6.0 to 7.3 for heparins. Rates per 1000 person-years for major bleeding ranged from 0 to 4.9 for all DOACs, 4.3 to 6.7 for warfarin, and 3.7 to 4.6 for heparins.

IMPLICATIONS

With results from clinical trials evaluating DOACs in the pediatric population expected in the next 2 years, these descriptive real-world data may provide a baseline understanding of current prescribing patterns and outcomes associated with the use of DOACs and other anticoagulants in routine pediatric clinical practice. This information represents the use of real-world evidence and may function as the benchmark for evaluating changes in prescription practices and potential outcomes in the future.

Efficacy of rivaroxaban for the treatment of Chinese patients with acute pulmonary embolism: A retrospective study

Pulmonary embolism (PE) is a life-threatening disease, which accounts for the major type of venous thromboembolism. Currently, there is limited understanding and management for PE. Rivaroxaban is reported to treat patients with PE. However, there is still insufficient evidence on rivaroxaban for the treatment of Chinese patients with acute PE. Thus, this retrospective study investigated the benefits and safety of rivaroxaban for Chinese patients with acute PE.A total of 72 Chinese patient cases with acute PE were analyzed in this study. Of these, 36 cases who received rivaroxaban mono-therapy were assigned to the treatment group, while the remaining 36 cases who received standard therapy were assigned to the control group. The benefits were assessed by the duration of hospital stay, treatment satisfaction, and safety.After treatment, rivaroxaban mono-therapy showed better benefits in decreasing the duration of hospital stay (P < .01), increasing treatment satisfaction (P < .01), and reducing mild bleeding (P = .02) in Chinese patients with acute PE, than standard therapy.The results of this study indicated that rivaroxaban may provide more benefits than the standard therapy for Chinese patients with acute PE. Future studies are still needed to warrant the current results.

Risk Assessment and Outcome of Venous Thromboembolism in Pediatric Population in an Academic Care Center of a Low-Middle Income Country

Venous thromboembolism (VTE) is a recognized complication of hospital stay in young patients in many developed countries, but such an information is largely unavailable from a low middle-income country (LMIC). This study aimed at identifying the frequency, risk factors, treatment options and outcome of deep venous thrombosis/pulmonary embolism (DVT/PE) in pediatric population in a tertiary care center from a LMIC. International classification of disease, ninth revision (ICD-9) was used to identify VTE in patients aged 0-18 years during January 2011 to September 2019. In-house computerized system was used to collect data for demographics, clinical and laboratory details. SPSS version 19 was used to analyzed data. The study was approved by Institutional ethical review committee (3872-Pat-ERC-15). During the study period, 134617 pediatric patients were hospitalized, DVT/PE was observed in 77 unique patients (47 males and 30 females) with a median (IQR) age of 14 (5-16) years equivalent to 5.9 VTE events /10,000 hospital admissions. Malignancy, community acquired infections and autoimmune diseases were the predominant risk factors (75%) in adolescent age-group while surgery for congenital heart anomalies was the primary reason (71%) in infants. Overall, lower extremity thrombosis was the most frequent (51%) followed by pulmonary embolism (25%). and upper extremity thrombosis (24%). Enoxaparin and unfractionated heparin were mainly used to treat VTE and all-cause mortality was 13% in the cohort studied. We observed substantial VTE events in pediatric patients during their hospital stay in a tertiary care center of a low-middle income country.