Duration of anticoagulant therapy in pediatric venous thromboembolism: Current approaches and updates from randomized controlled trials

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.

The Incidence of Thromboembolic Events During Hospitalizations Following Surgical Resection of Lower Extremity Sarcomas in Children: Utilizing the Pediatric Health Information System Database

BACKGROUND

Venous thromboembolism (VTE) is a frequent occurrence during treatment for adults with sarcoma. The incidence and underlying risk factors of postsurgical VTE in children and adolescents undergoing resection of sarcoma are unknown.

METHODS

Using International Classification of Disease revision-9 diagnostic and procedure codes, the Pediatric Health Information System database was queried for patients aged 18 years and younger, discharged from 2004 to 2015 with a diagnosis of lower extremity malignant neoplasm who had a tumor resection or amputation performed during the encounter. Malignant neoplasms of the pelvic bones and soft tissues were categorized as "pelvis tumors", whereas malignant neoplasms of bone and soft tissues of the lower limbs were categorized as "lower limb tumors". Hospitalizations were evaluated for the occurrence of VTE. Demographic characteristics (age at admission, sex, race, and race/ethnicity) and incidence of VTE were reported.

RESULTS

There were 2400 patients identified. Of these, 19 experienced VTE (0.79%) during their surgical hospitalization encounter. By anatomic group, the rate of VTE was 1.4% (CI: 0.5%-3.2%) for tumors in the pelvis and 0.6% (CI: 0.3%-1.0%) in lower limb tumors. Categorizing by age, the incidence of VTE was 1.2% in patients aged zero to 5, 0.3% in patients 6 to 13, and 1.2% in patients 14 to 18 years old. (Table 1). The extremely low rate of VTE occurrence precluded further analysis of risk factors.

CONCLUSIONS

In this analysis, postsurgical VTE during hospitalization after pelvic and lower extremity sarcoma resection was an uncommon event in children and adolescents. There seemed to be an increased incidence of postsurgical VTE in pelvic tumors when compared with lower limb tumors, however, the rarity of all events precluded formal statistical analysis. A more robust data set would be required to determine if there are subsets of children and adolescents with sarcoma at higher risk of VTE that could benefit from thromboprophylaxis in the postoperative setting.

LEVEL OF EVIDENCE

Level II.

Case Report of a Massive Life-threatening Neonatal Thrombosis Treated With a Targeted, Goal-oriented Scheme of Urokinase

BACKGROUND

Thrombotic events are severe, often under-diagnosed, complications occurring in newborn infants during their hospital stay. Currently, there is no consensus regarding the optimal treatment scheme for thrombolysis in neonates.

OBSERVATIONS

We present the case of a newborn suffering from a life-threatening thrombosis. Diagnosis was suggested by a gradual increase of C-reactive protein, with repeatedly normal procalcitonin. Thrombosis was successfully and safely treated with a long scheme of 21 days of urokinase, supported by vascular ultrasound and d-dimer trend.

CONCLUSIONS

Laboratory and ultrasound results may help in adjusting the duration of the thrombolytic treatment, allowing for longer therapeutic schemes that could optimize treatment success. In addition, our case may suggest a possible combined role of C-reactive protein and procalcitonin as an early diagnostic aid in neonatal thrombosis.

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.

Secondary thrombosis prevention practice patterns in pediatrics: Results of an international survey

Background

Pediatric venous thromboembolism (VTE) rates continue to increase. Although most children present with transient provoking factors, some have persistent prothrombotic risks beyond the initial treatment period warranting secondary anticoagulation. Current pediatric VTE guidelines provide limited recommendations in this regard.

Objectives

Our primary objective was to identify key influences on pediatric thrombosis physicians' decisions to initiate secondary anticoagulation.

Methods

We targeted pediatric hematologists/oncologists internationally using Duration of Therapy for Thrombosis in Children, Children's Hospital Acquired Thrombosis consortium, and Venous Thromboembolism Network US pediatric subgroup membership rosters, who self-identified as primary outpatient thrombosis providers. Of 124 total surveys distributed, 61 complete surveys were evaluable. We defined secondary anticoagulation as anticoagulant use beyond the initial treatment period, on a daily basis (extended) or limited to periods of superimposed clinical risk factors (episodic).

Results

Pediatric thrombosis physicians surveyed indicated that they prescribe secondary anticoagulation in <25% of children despite persistent risks. Among those who indicated use of secondary anticoagulation, the preferred modality was extended anticoagulation in children with a history of recurrent unprovoked VTE (98%), chronic central venous catheter (74%), and potent thrombophilia (73%). Episodic anticoagulation was preferred in children with a history of mild thrombophilia (54%). Respondents were more likely to prescribe secondary anticoagulation for adolescents as opposed to children <12 years old.

Conclusions

Among pediatric thrombosis physicians surveyed, they perceived the prevalence of persistent prothrombotic risks to be high in children who have completed a course of anticoagulation for provoked VTE; however, estimated use of secondary anticoagulation was low. Studies involving real-world data are needed to further evaluate use of secondary anticoagulation in this setting.

Antiphospholipid syndrome with mesenteric vein thrombosis and hepatic nodular regenerative hyperplasia in a child: A case report

RATIONALE

Hepatic nodular regenerative hyperplasia (NRH), a nonspecific change in the liver parenchyma, is very rare in children. Hepatic microvascular changes may be the cause, as these vascular changes are uncommon in children. Antiphospholipid syndrome (APS), an autoimmune disease characterized by vascular thromboembolism, is extremely unusual in children.

PATIENT CONCERNS

A 13-year-old girl who presented with abdominal pain and elevated liver enzymes was transferred to our hospital. Abdominal computed tomography and magnetic resonance imaging showed a massive mesenteric venous thrombus and a malignant mass with liver metastasis.

DIAGNOSES

Her immunological profile was positive for antinuclear antibodies (ANA) at a titer of 1/160 (nucleolar pattern), anticardiolipin antibodies (aCL) immunoglobulin G, and anti-histone antibody. A liver biopsy revealed hepatic NRH.

INTERVENTIONS

The patient was initially started on heparin upon hospitalization and switched to warfarin and a vitamin K antagonist and continued treatment with international normalized ratio monitoring.

OUTCOMES

Her symptoms improved after 9 months of anticoagulation therapy.

LESSONS

In the presence of hepatic NRH or vascular thrombosis in children, we recommend that APS be differentially diagnosed using lupus anticoagulant and aCL and appropriate management be implemented.

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.

Venous Thromboembolism in Children: From Diagnosis to Management

Venous thromboembolism (VTE) in children is a rare occurrence, although in recent decades we have seen an increase due to several factors, such as the rise in survival of subjects with chronic conditions, the use of catheters, and the increased sensitivity of diagnostic tools. Besides inherited thrombophilia, acquired conditions such as cardiovascular diseases, infections, chronic disorders, obesity and malignancy are also common risk factors for paediatric VTE. The treatment of paediatric VTE consists of the use of heparins and/or vitamin K antagonists to prevent dissemination, embolization, and secondary VTE. Randomized clinical trials of direct oral anticoagulants in paediatric VTE are ongoing, with the aim to improve the compliance and the care of patients. We reviewed the physiological and pathological mechanisms underlying paediatric thrombosis and updated the current diagnosis and treatment options.

Management and outcomes of pediatric septic thrombophlebitis: a case series

Septic thrombophlebitis is a potentially life-threatening condition. Pediatric hematologists are often consulted to provide recommendations regarding anticoagulation management. We conducted a ten-year retrospective, single-center study of hospitalized pediatric patients who were treated for septic thrombophlebitis. Our primary outcome was resolution of thrombophlebitis. Twenty-eight patients were included in the study. Eighty-nine percent of patients received both antibiotic and anticoagulation therapy. The median durations of intravenous and total antibiotic therapy were 47.5 days (range 14-120) and 65 days (range 14-281), respectively, and median duration of anticoagulation therapy was 92 days (range 41-268). Resolution of thrombosis defined by magnetic resonance imaging, computed tomography, or ultrasound imaging was documented in 16 of 28 (57%) patients. Despite the high rate of persistent thrombosis, there was a low risk of relapse of infection in cases where antibiotic and/or anticoagulation was discontinued prior to complete resolution of the thrombus. Further research is needed to determine if duration of antibiotic and/or anticoagulation treatment can be shortened.

Genotype phenotype correlation in a pediatric population with antithrombin deficiency

Inherited antithrombin (AT) deficiency is a rare autosomal dominant disorder, caused by mutations in the AT gene (SERPINC1). Considering that the genotype phenotype relationship in AT deficiency patients remains unclear, especially in pediatric patients, the aim of our study was to evaluate genotype phenotype correlation in a Serbian pediatric population. A retrospective cohort study included 19 children younger than 18 years, from 15 Serbian families, with newly diagnosed AT deficiency. In 21% of the recruited families, mutations affecting exon 4, 5, and 6 of the SERPINC1 gene that causes type I AT deficiency were detected. In the remaining families, the mutation in exon 2 causing type II HBS (AT Budapest 3) was found. Thrombosis events were observed in 1 (33%) of those with type I, 11 (85%) of those with AT Budapest 3 in the homozygous respectively, and 1(33%) in the heterozygous form. Recurrent thrombosis was observed only in AT Budapest 3 in the homozygous form, in 27% during initial treatment of the first thrombotic event. Abdominal venous thrombosis and arterial ischemic stroke, observed in almost half of the children from the group with AT Budapest 3 in the homozygous form, were unprovoked in all cases.Conclusion: Type II HBS (AT Budapest 3) in the homozygous form is a strong risk factor for arterial and venous thrombosis in pediatric patients. What is Known: • Inherited AT deficiency is a rare autosomal dominant disorder, caused by mutations in the SERPINC1gene. • The genotype phenotype correlation in AT deficiency patients remains unclear, especially in pediatric patients. What is New: • The genetic results for our paediatric population predominantly showed the presence of a single specific mutation in exon 2, that causes type II HBS deficiency (AT Budapest 3). • In this group thrombosis mostly occurred as unprovoked, in almost half of them as abdominal thrombosis or stroke with high incidence of recurrent thrombosis, in 27% during initial treatment.