Treatment of Pediatric Venous Thromboembolism

Pediatric Patients with Symptomatic CVAD-Related Thrombosis

Recommendations three through five pertain to CVAD-associated thrombosis, so they are reviewed together.

Recommendation 3. No removal of a functioning CVAD is suggested if venous access is still required (evidence quality: low certainty; recommendation strength: conditional).Recommendation 4. It is recommended to remove a nonfunctioning or unneeded CVAD (evidence quality: low certainty; recommendation strength: strong).Recommendation 5. It is suggested to delay CVAD removal until after initiation of anticoagulation (days), rather than immediate removal if the CVAD is nonfunctioning or no longer needed (evidence quality: low certainty; recommendation strength: conditional).

Recommendation 4. It is recommended to remove a nonfunctioning or unneeded CVAD (evidence quality: low certainty; recommendation strength: strong).

Recommendation 5. It is suggested to delay CVAD removal until after initiation of anticoagulation (days), rather than immediate removal if the CVAD is nonfunctioning or no longer needed (evidence quality: low certainty; recommendation strength: conditional).

CVAD is the most common precipitating factor for pediatric VTE, particularly in neonates and older children.¹ Based on limited direct and indirect observational studies, there is low evidence of benefit for CVAD removal, but high-quality indirect evidence of harm and high cost, which the panel felt justified the strong recommendation for removing an unneeded or nonfunctioning line. If ongoing care can be safely administered without central access, removing the thrombosis stimulus is recommended. The guideline suggests keeping a functioning CVAD in a patient who requires ongoing venous access and placing high value on avoiding new line insertion when access sites may be limited to avoid the potential thrombogenic effect of new line placement.

In the limited direct and indirect observational studies identified, the optimal timing of CVAD removal is uncertain. Given the potential risk of emboli leading to pulmonary embolism or stroke, prior publications have suggested delaying removal until after three to five days of anticoagulation, particularly in children with known or potential right-to-left shunts.⁴ The risk of infection and bleeding with anticoagulation prior to CVAD removal was considered small by the panel. This recommendation is primarily based on the panel’s anecdotal experience and first principles, which is a limitation.

Methods in Preparing Guideline. The panel included pediatric experts with clinical and research expertise in the guideline topic, including nine hematologists, one intensivist, one cardiologist, one hematology pharmacist, and one anticoagulation nurse practitioner. It also included two methodologists with evidence appraisal and guideline development expertise, as well as two patient representatives.

The panel brainstormed and prioritized questions to be addressed and selected outcomes of interest for each question. The McMaster University GRADE Centre vetted and retained researchers to conduct or update systematic evidence reviews and coordinate the guideline development using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.⁶ For each guideline question, the results of systematic reviews were summarized in GRADE Evidence-to-Decision tables. The evidence quality was categorized into four levels ranging from very low to high. For each recommendation developed, the panel agreed on the evidence quality, balance of benefits and harms of compared management options with consideration of resource use, and inferences regarding the potential associated values and preferences. The panel addressed 26 questions, which generated 30 recommendations.

Draft recommendations were made available online for review by stakeholders, including allied organizations, medical professionals, patients, and the public. Revisions were made to address pertinent submitted comments, but the recommendations were not changed. After approval by ASH, the guideline was subjected to peer review by Blood Advances.

Sources of Potential Conflict of Interest or Bias. The guideline was developed and funded by ASH. All participants’ conflicts of interest were managed according to ASH policies based on recommendations of the Institute of Medicine and the Guideline International Network. A majority of the guideline panel had no conflicts. During deliberations, panelists with direct financial interests were recused from making judgments about relevant recommendations. The McMaster University-affiliated researchers had no conflicts.Generalizability. While this guideline included 30 recommendations, the ones highlighted apply to the most commonly seen pediatric VTE cases in hospital medicine. ASH emphasized that these guidelines should not be construed as the standard of care, but as a guide to help clinicians make treatment decisions for children with VTE and to enable them to individualize care when needed. The greatest limitation of this guideline is the lack of strong direct supporting evidence in pediatric VTE management.

Generalizability. While this guideline included 30 recommendations, the ones highlighted apply to the most commonly seen pediatric VTE cases in hospital medicine. ASH emphasized that these guidelines should not be construed as the standard of care, but as a guide to help clinicians make treatment decisions for children with VTE and to enable them to individualize care when needed. The greatest limitation of this guideline is the lack of strong direct supporting evidence in pediatric VTE management.