Venous thromboembolic complications (VTE) in children: first analyses of the Canadian Registry of VTE

Abstract

Deep vein thrombosis (DVT) and pulmonary embolism (PE) occur in pediatric patients; however, the incidence, associated morbidity, and mortality are unknown. A Canadian registry of DVT and PE in children (ages 1 month to 18 years) was established July 1, 1990 in 15 tertiary- care pediatric centers. One-hundred thirty-seven patients were identified prospectively and are the subject of this report. The incidence of DVT/PE was 5.3/10,000 hospital admissions or 0.07/10,000 children in Canada. Infants under 1 year old and teenagers predominated with equal numbers of both sexes. DVT were located in the upper (n = 50) and lower (n = 79) venous system, or as PE alone (n = 8). Central venous lines (CVLs) were present in approximately 33% of children with DVT (n = 45). Associated conditions were present in 96% of children and 90% of children had two or more associated conditions for DVT. DVT was diagnosed by venography (n = 83), duplex ultrasound (n = 37), and other combinations (n = 17). Twenty-two of the 31 ventilation/perfusion scans performed were interpreted as high-probability scans for PE. Therapy consisted of heparin (n = 115), thrombolysis (n = 15), surgical removal of a CVL or thrombus (n = 22), and oral anticoagulant therapy (n = 103). Significant bleeding complications did not occur. However, three (2.2%) children died as a direct consequence of their thromboembolic disease; DVT reoccurred in 23 children and postphlebitic syndrome (PPS) occurred in 26. In conclusion, DVTs occur in a significant number of hospitalized children with a mortality of 2.2%. Complications are not hemorrhagic, but thrombotic, and characterized by PE, recurrent disease, and PPS. In contrast to adults, the upper venous system is frequently affected because of the use of CVLs. The frequency of DVT/PE justifies controlled trials of primary prophylaxis in high-risk groups, and therapeutic trials to determine optimal treatment.

Thrombotic events after pediatric liver transplantation

“…The incidence of symptomatic CVL‐related DVT was 6.8%. Children with DVT may experience significant morbidity and mortality, including mortality directly attributable to DVT and pulmonary embolism in 2.2%, and morbidity related to the development of recurrent thrombosis and post‐phlebitic syndrome in 8.1% and 12.4% respectively (4, 5). The post‐phlebitic syndrome may develop within two yr after the initial DVT and present with potentially disabling symptoms of pain, heaviness, discoloration, and/or ulceration in the affected extremity (4).…”

“…The post‐phlebitic syndrome may develop within two yr after the initial DVT and present with potentially disabling symptoms of pain, heaviness, discoloration, and/or ulceration in the affected extremity (4). Solid organ transplant recipients were not specifically considered in these previous studies; however, the vast majority of these children did have associated medical conditions such as malignancy (4, 5). None of our study subjects with TE had known malignancy or post‐transplant lymphoproliferative disorder.…”

“…Indeed, DVT and symptomatic venous thromboembolic disease were reported in 11 (3.7%) of 299 of adult LT patients over a mean follow‐up period of 28 months (3). Deep venous thromboembolic disease may contribute to morbidity and mortality after pediatric LT, with outcome studies of DVT from the Canadian Childhood Thrombophilia Registry reporting a 2.2% mortality rate directly attributable to thromboembolic disease with morbidities including recurrent thrombosis and post‐phlebitic syndrome rates of 8.1% and 12.4%, respectively, in children (4, 5).…”

Laser ablation of embryonic veins in children

“…The incidence of DVT in KTS has been estimated at 4% . In comparison, the Canadian pediatric thrombosis registry found the incidence of all DVT in the pediatric population to be 0.05% . Considering this dramatic increase in thromboembolic risk and the demonstrated safety profile of EVLT, prophylactic use of EVLT in pediatric KTS patients with enlarged embryonic veins should be strongly considered.…”

A six‐year old with fatal pulmonary embolism

“…However, in one series, pulmonary emboli were found in 3.7% of children at autopsy and had contributed to death in about 1%1. The Canadian registry, in 1994, was the first systematic evaluation of venous thromboembolism in children 2. They found a prevalence of 0.07/10 000 in children aged 1 mo to 18 y.…”