Venous thromboembolism in children and adolescents

Direct oral anticoagulant therapy in adolescent venous thromboembolism: A systematic review

Adolescent venous thromboembolism (VTE) has unique challenges in management, complications, and compliance to anticoagulants. Direct oral anticoagulants (DOACs) have been approved for pediatric VTE management, with an increasing use especially in adolescents. Primary objective is to evaluate the safety and efficacy of DOAC therapy in adolescent VTE. Secondary objectives include adverse events, bleeding events, and overall mortality. A SR protocol was registered in PROSPERO 2022 (CRD42022363928). Databases were searched from inception to September 22, 2022. Studies with children aged 10-18 years, VTE diagnosis, DOAC therapy, randomized control trials (RCTs), cohort, and relevant study types were included. Studies including prophylaxis, non-DOAC therapy, arterial thrombosis, age outliers, non-relevant study types were excluded. Findings are reported in accordance to PRISMA 2020. Nine reports from five studies, published between 2016 and 2022, were included. Rivaroxaban was the most common DOAC. VTE recurrence was 0.02% in the rivaroxaban phase III trial and one patient in the dabigatran phase IIb/III trial. Complete/partial thrombus resolution (CR/PR) was 76.6% in the rivaroxaban phase III trial, and 83.9% in the dabigatran phase IIb/III trial. CR/PR was found to be 68.4% in Dhaliwal et al. study and 83.3% in Hassan et al. study. Major bleeding occurred in one patient. Headache and gastrointestinal symptoms were commonly seen. All-cause mortality occurred in a patient due to cancer progression. DOAC therapy in adolescent VTE had CR/PR in two-thirds of the patients, with low incidence of VTE recurrence and major bleeding. As there are only two randomized controlled trial (RCTs), future adolescents' studies are required to validate our results.

My child's leg is in a plaster. Can they fly?

Air travel in a cast with a fracture is associated with an increased risk of leg swelling in a tight compartment. We have hypothesised that there should be an accessible, universal policy for travel recommendations with the cast supported by high-quality literature. We have checked the 20 biggest airlines looking for their guidance on travel recommendation /restrictions in the presence of a broken leg in a cast, particularly in children. We have also carried out a literature review in the last 30 years to ascertain whether there is the best evidence relating to flying safely with a child in a cast. Nine airlines have an accessible policy on flying in a cast. Most airlines recommend to delay the flight 24-48 h after cast application. Four airlines require splitting the cast if applied 48 h before the flight. None of the airlines have specific recommendations related to children. A comprehensive review of the literature revealed 11 relevant articles. None of those studies were experimental studies on flying with a fracture, only one assessed flying in a cast. We did not find a research study focused specifically on children. The recommendation regarding flying restrictions varies among airlines and often there is no coherent policy available. The existing recommendations cannot be fully supported by experimental studies in the existing literature. Flying in a full cast should be delayed until 24-48 h after cast application. If the flight is an emergency, the cast should be bivalved.

Coagulation Abnormalities and Clinical Complications in Children With SARS-CoV-2: A Systematic Review of 48,322 Patients

Given the limited information on the coagulation abnormalities of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in pediatric patients, we designed a systematic review to evaluate this topic. A comprehensive literature search was conducted for "SARS-CoV-2," "coagulopathy," and "pediatrics." Two authors independently screened the articles that the search returned for bleeding, thrombosis, anticoagulant and/or antiplatelet usage, and abnormal laboratory markers in pediatric patients with SARS-CoV-2, and the authors then extracted the relevant data. One hundred twenty-six publications were included. Thirty-four (27%) studies reported thrombotic complications in 504 patients. Thirty-one (25%) studies reported bleeding complications in 410 patients. Ninety-eight (78%) studies reported abnormal laboratory values in 6580 patients. Finally, 56 (44%) studies reported anticoagulant and/or antiplatelet usage in 3124 patients. The variety of laboratory abnormalities and coagulation complications associated with SARS-CoV-2 presented in this review highlights the complexity and variability of the disease presentation in infants and children.

Current Antithrombotic Therapy Strategies in Children with a Focus on Off-Label Direct Oral Anticoagulants-A Narrative Review

(1) Background: The incidence of thromboembolic events is relatively low in the general population, but it increases in hospitalized children and those who underwent thrombogenic procedures. Although the evidence regarding direct oral anticoagulants (DOACs) in children with venous thromboembolism (VTE) is growing, DOACs were excluded from existing guidelines due to the lack of reliable data at that moment. Therefore, current evidence on VTE management in children needs to be critically reviewed. (2) Methods: We have conducted a literature search in the Scopus, EMBASE, and MEDLINE databases using prespecified keywords to retrieve studies published between 2010 and 2022. (3) Results: Clinical trials highlighted that rivaroxaban and dabigatran had predictable pharmacokinetic and pharmacodynamic profiles in children, similar to those observed in adults. Dabigatran and rivaroxaban had a similar safety profile to standard therapy but improved thrombotic burden and resolution during follow-up. Most studies involving apixaban and edoxaban are ongoing, and results are awaited. (4) Conclusions: Dabigatran and rivaroxaban could be valid therapeutic options for VTE management in children. In the case of apixaban and edoxaban, results from ongoing clinical studies are required before using them in pediatric VTE.

Venous Thromboembolism After Pelvic Osteotomy in Adolescent Patients: A Database Study Characterizing Rates and Current Practices

BACKGROUND

Current risks and practices in medical prophylaxis of venous thromboembolism (VTE) after major elective lower extremity surgeries such as pelvic osteotomies have not been well-defined in the pediatric population. The purpose of this study was to (1) evaluate population rates of VTE in adolescents undergoing pelvic osteotomies, and (2) characterize current practices on types of VTE prophylaxis being utilized after pelvic osteotomies.

METHODS

The study evaluated the Pediatric Health Information System database between October 1, 2015 and January 1, 2020 for patients between 10 and 18 years of age meeting selected ICD-10 procedure and diagnosis codes relating to pelvic osteotomies. The rate of VTE was calculated within 90 days of index procedure. Types of pharmacologic prophylaxis were characterized. Continuous variables were compared with 2-sample t tests; proportions and categorical variables were compared with Fisher exact or χ2 tests, all with 2-tailed significance <0.05.

RESULTS

Of 1480 included patients, 9 were diagnosed with VTE within 90 days of surgery (VTE rate: 0.61%). Four of 9 (44.4%) had received pharmacologic prophylaxis postoperatively. There were no differences in baseline demographics or length of stay between patients that did or did not develop VTE (P>0.05). Overall, 52.0% received at least one form of pharmacologic prophylaxis postoperatively. The most common pharmacologic prophylaxis used was aspirin (47.6%), of which 64.4% received 81 mg dosing. There was no difference in VTE rates in those with or without prophylaxis (0.52% vs. 0.70%, P=0.75). However, those prescribed prophylaxis were significantly older (15.2±2.3 vs. 13.6±2.4 y, P<0.0001) and had a higher proportion of females (71.8% vs. 54.6%, P<0.01).

CONCLUSIONS

The overall rate of VTE in pediatric patients after pelvic osteotomies is non-negligible. There is heterogeneity in the type of anticoagulant utilized; however, VTE prophylaxis is most commonly prescribed in older adolescents and female patients. Guidelines for medical prevention of deep venous thrombosis and pulmonary embolism in the pediatric population are warranted after hip preservation surgery.

LEVEL OF EVIDENCE

Level IV, case series.

The survival benefit of low molecular weight heparin over unfractionated heparin in pediatric trauma patients

INTRODUCTION

Venous thromboembolism (VTE) prophylaxis in pediatric patients is controversial and is mainly dependent on protocols derived from adult practices. Our study aimed to compare outcomes among pediatric trauma patients who received low molecular weight heparin (LMWH) compared to those who received unfractionated heparin (UFH).

METHODS

We performed 2 years (2015-2016) retrospective analysis of the Pediatrics ACS-TQIP database. Pediatric trauma patients (age ≤17) who received thromboprophylaxis with either LMWH or UFH were included. Patients were stratified into three age groups. Analysis of each subgroup and the entire cohort was performed. Outcome measures included VTE events (deep vein thrombosis [DVT] and pulmonary embolism [PE]), hospital and ICU length of stay (LOS) among survivors, and mortality. Propensity score matching was used to match the two cohorts LMWH vs UFH.

RESULTS

A matched cohort of 1,678 pediatric trauma patients was analyzed. A significant difference in survival, DVT events, and in-hospital LOS was seen in the age groups above 9 years. Overall, the patients who received LMWH had lower mortality (1.4% vs 3.6%, p<0.01), DVT (1.7% vs 3.7%, p<0.01), and hospital LOS among survivors (7 days vs 9 days, p<0.01) compared to those who received UFH. There was no significant difference in the ICU LOS among survivors and the incidence of PE between the two groups.

CONCLUSION

LMWH is associated with increased survival, lower rates of DVT, and decreased hospital LOS compared to UFH among pediatric trauma patients age 10-17 years.

LEVEL OF EVIDENCE

Level III Prophylactic.

STUDY TYPE

Prophylactic.

Central venous catheters are an important factor in paediatric thrombosis

AIM

To establish the incidence and characteristics of paediatric thrombosis (PT) in a Canadian tertiary care centre during the era of low molecular weight heparin (LMWH).

METHODS

A retrospective observational case study of all patients <18 years of age evaluated for arterial and venous thrombosis from May 2008 to July 2018 at McMaster Children's Hospital was conducted through the electronic medical record.

RESULTS

The incidence of PT was 52.2 per 10 000 hospital admissions (n = 477/91 462). Provoked thrombosis was more prevalent (88.9%, n = 424/477) than unprovoked (2.9%, n = 14/477) or idiopathic thrombosis (4%, n = 19/477). Half of PT were in children <2 years (51.2%, n = 244/477). Central vascular catheterisation was a contributory factor in more than half of thrombotic events (56.2%, n = 268/477), while trauma (1.1%, n = 5/477), oral contraceptives (4%, n = 19/477), infection (4%, n = 19/477), surgery (6.9%, n = 33/477) and malignancy (8.4%, n = 40/477) were also risk factors. Arterial ischaemic stroke was diagnosed in 11.1% of cases (n = 53/477), while pulmonary embolism was identified in 7.1% (n = 34/477) and 1.7% of cases were fatal (n = 8/477). LMWH was the first-line therapeutic of choice (47.8%, n = 228/477), with 28.1% (n = 134/477) requiring no intervention.

CONCLUSION

These data reiterate the elevated thrombosis risk to which infants and children with central vascular access are exposed.

Venous thromboembolism in children undergoing surgery: incidence, risk factors and related adverse events

Background

Although less common in adults, venous thromboembolism (VTE) in children is a highly morbid, preventable adverse event. While VTE has been well studied among pediatric hospitalized and trauma patients, limited work has been done to examine postoperative VTE in children undergoing surgery.

Methods

Using data from National Surgical Quality Improvement Project Pediatric database (NSQIP-P) from 2012 to 2016, a retrospective cohort analysis was performed to determine the incidence of, and risk factors for, VTE in children undergoing surgery. Additionally, the relationships between VTE and other postoperative adverse outcomes were evaluated.

Results

Of 361 384 pediatric surgical patients, 378 (0.10%) were identified as experiencing postoperative VTE. After controlling for patient and surgical factors, we found that American Society of Anesthesiologists (ASA) class of II or greater, aged 16–18 years, non-elective surgery, general surgery (compared with several other surgical specialties), cardiothoracic surgery (compared with general surgery) and longer operative time were significantly associated with VTE in pediatric patients (p<0.001 for each comparison). Furthermore, a majority of adverse events were found to be associated with increased risk of subsequent VTE (p<0.001).

Conclusion

In a large pediatric surgical population, an incidence of postoperative VTE of 0.10% was observed. Defined patient and surgical factors, and perioperative adverse events were found to be associated with such VTE events.

Central Venous Catheter-associated Venous Thromboembolism in Children With Hematologic Malignancy

In pediatric oncology, the diagnosis of a hematologic malignancy and presence of a central venous catheter (CVC) have been identified as significant risk factors for the development of a venous thromboembolism (VTE). There remain little data regarding CVC factors associated with CVC-related VTE. Using the VTE and oncology database in a quaternary care center, a retrospective cohort study was conducted in children below 18 years old with hematologic cancer from November 5, 2012 to April 4, 2016. Patient, CVC factors, and VTE occurrence were analyzed to identify significant patient and CVC factors associated with the development of clinically identified CVC-related VTE. Utilizing the χ, Mann-Whitney, and the Fisher exact tests, patient factors were compared across VTE yes/no groups. Of the 198 study patients, 22 VTE cases were identified. Eighteen VTE events were CVC-associated, occurring in 9% of study population. Peripherally inserted central catheter lines and older ages were associated with VTE. The use of tissue-plasminogen activator for CVC occlusion was associated with decreased VTE rates, suggesting a protective potential.

Fitness to fly in the paediatric population, how to assess and advice

The number of children on commercial aircrafts is rising steeply and poses a need for their treating physicians to be aware of the physiologic effects and risks of air travel. The most important risk factors while flying are a decrease in partial oxygen pressure, expansion of trapped air volume, low cabin humidity, immobility, recirculation of air and limited options for medical emergencies. Because on-board medical emergencies mostly concern exacerbations of chronic disease, the medical history, stability of current disease and previous flight experience should be assessed before flight. If necessary, hypoxia altitude simulation testing can be performed to simulate the effects of in-flight hypoxia. Although the literature on paediatric safety of air travel is sparse, recommendations for many different situations can be given.

CONCLUSION

We present an overview of the most up to date recommendations to ensure the safety of children during flight. What is Known: • Around 65% of on-board medical emergencies are complications of underlying disease. • In children, the three most common emergencies during flight concern respiratory, neurological and infectious disease. What is New: • Although studies are scarce, some advices to ensure safe air travel can be given for most underlying medical conditions in children, based on physiology, studies in adults and expert opinions. • In former preterm infants without chronic lung disease, hypoxia altitude simulation testing to rule out in-flight desaturation is not recommended.