Pediatric thromboembolism is increasingly encountered in critical care settings, but pediatric‑specific thrombolysis protocols are not well defined and concerns about safety remain. Systemic thrombolysis with tissue plasminogen activator (tPA) can restore vessel or valve patency in children, yet evidence guiding dose, duration, and monitoring is limited. This analysis reports a decade of single‑center experience implementing a high‑dose, tailored systemic tPA protocol as a joint Pediatric Hematology and Cardiac ICU quality improvement initiative.
The primary objective was to evaluate the efficacy and safety of a tailored, prolonged systemic tPA protocol for treating vessel thrombosis and mechanical valve obstruction in infants and children. A secondary aim was to characterize D‑dimer kinetics by clinical indication to explore whether fibrinolytic marker trajectories differ between groups and could inform management.
This retrospective cohort study was conducted at a tertiary pediatric cardiac ICU and covered treatments provided from July 2014 through March 2024. Extracted data included patient demographics, tPA dosing regimens, laboratory trends including D‑dimer, transfusion requirements, imaging‑confirmed therapeutic success, and adverse events. Statistical analysis of D‑dimer trajectories used Welch’s t‑test to compare patterns between indications. The report includes all patients who received systemic tPA during the study period.
Initial systemic tPA dosing in this cohort had a median starting rate of 0.1 mg/kg/h (IQR: 0.06–0.1 mg/kg/h). Selected cases required dose escalation, with rates increased up to 0.5 mg/kg/h. Treatment courses were prolonged compared with many short‑infusion regimens, with a mean duration of therapy of 3.9 ± 2.8 days. The protocol was described as tailored, indicating adjustments based on clinical response, imaging, and laboratory monitoring.
Twenty‑two patients received systemic tPA across a range of indications. Median patient age was 287 days (IQR: 64.8–940 days), and 32% were younger than 90 days:
Restoration of mechanical valve mobility occurred in 80% of valve obstruction cases. Complete thrombus resolution was reported for all patients treated for venous thromboses, the single coronary thrombosis, and the single arterial ischemic stroke case. These outcomes suggest high rates of effectiveness for the tailored prolonged systemic tPA regimen in this cohort when administered with intensive monitoring.
The study analyzed D‑dimer trajectories and found statistically significant differences between patients treated for vessel thrombosis and those treated for mechanical valve obstruction (p < 0.01). These distinct fibrinolytic profiles imply that D‑dimer trends may reflect differing pathophysiology or response to thrombolytic therapy and could potentially serve as a biomarker to guide treatment duration or dosing adjustments. The source reports the statistical difference but does not provide detailed numerical trajectories in the abstract.
Adverse events were documented and categorized. Minor bleeding occurred in 23% of patients. One patient (5%) experienced a subdural hemorrhage. Despite bleeding events, all patients in the cohort survived to hospital discharge. The authors emphasize that the protocol was delivered under strict monitoring, and that safety outcomes should be interpreted in the context of intensive surveillance and individualized clinical decision making.
In this single‑center retrospective experience, a tailored, prolonged systemic tPA protocol appeared effective for restoring valve mobility and achieving thrombus resolution across several pediatric indications, with an acceptable adverse event profile when used with rigorous monitoring. Distinct D‑dimer patterns between indications were identified and may assist in guiding thrombolytic therapy, though the abstract does not detail how these patterns should be operationalized.
The authors recommend multicenter studies to validate findings and to support development of standardized pediatric protocols for systemic thrombolysis, acknowledging current gaps in pediatric‑specific guidance and ongoing safety concerns.
This analysis is retrospective and single‑center, limiting generalizability. Detailed numerical data for D‑dimer trajectories, transfusion specifics, and individual case characteristics are not provided in the abstract and would be necessary to inform protocol standardization. The authors call for multicenter investigations to corroborate effectiveness, refine dosing strategies, and better define safety signals in diverse pediatric populations.