Thrombosis is the formation of a blood clot (partial or complete blockage) within blood vessels, whether venous or arterial, limiting the natural flow of blood and resulting in clinical sequela.~Incidence of childhood thrombosis is 0.07-0.14/10,000 in the general population. This incidence has been reported to be 5.3/10,000 in children presenting to hospital, 0.51/10,000 in all newborns and 0.24/10,000 in children in neonatal intensive care units . Pediatric thrombosis is multifactorial, and usually risk factors either congenital or acquired are present. . Patient may has one risk factor or more such as sepsis, cancers, congenital heart disease, post surgery , central venous catheter insertion, nephrotic syndrome, systemic lupus erythromatosis and inflammatory bowel disease. If there's no obvious risk factor for thrombosis, hereditary thrombophilia is suspected which results when an inherited factor, such as antithrombin , protein C or protein S deficiency.~There are three changes described by Virchow in 1856 are involved in the formation of thrombosis:~Changes in blood flow (rheology, stasis)~Changes in the vascular wall~Changes in the blood levels of coagulation factors The diagnosis of thrombosis is made more frequently and more easily in children due to noninvasive diagnos-tic methods [Doppler and ultrasonography (US), echo-cardiography, computed tomography (CT) and magnet-ic resonance imaging (MRI)]. The morbidity and mortality rates are high, although it occurs more rarely compared with adult thrombosis and does not develop in the absence of a triggering factor; the rate of mortality related with direct venous thromboembolism is 2.2%, the frequency of post-thrombotic syndrome is 12.4%, and the recurrence rate for thrombosis is 8.1%.
Pediatric thrombosis is multifactorial, and usually risk factors either congenital or acquired are present.~Patient may has one risk factor or more such as sepsis, cancers, congenital heart disease, post surgery , central venous catheter insertion, nephrotic syndrome, systemic lupus erythromatosis and inflammatory bowel disease.~If there's no obvious risk factor for thrombosis, hereditary thrombophilia is suspected which results when an inherited factor, such as antithrombin , protein C or protein S deficiency.