Pediatric Clinics of North America - CIPERJ

VENOUS THROMBOEMBOLISM IN CHILDREN
309
childhood), a flank mass that often is palpable on examination. RVT in
older children often is associated with nephrotic syndrome (a risk factor
for VTE in general) and, hence, may present with associated stigmata of peripheral
and periorbital edema when diagnosed at presentation of nephrosis
[11]. Thrombocytopenia may be a presenting manifestation not only of RVT
but also of an intracardiac (eg, right atrial) thrombus, especially as in cases
of CRT associated with sepsis and DIC. Portal vein thrombosis characteristically
presents with splenomegaly and is associated with thrombocytopenia
and, often, anemia; gastrointestinal bleeding at presentation typically
signals the presence of gastroesophageal varices as a result of portal hypertension.
Internal jugular vein thrombosis may manifest with neck pain or
swelling and, in the Lemierre syndrome, also is associated classically with
fever, trismus, and a palpable mass in the lateral triangle of the neck. Isolated
intracardiac thrombosis in association with cardiac surgery or central
venous catheter placement most often is asymptomatic.
Chronic VTE may be diagnosed incidentally without signs or symptoms
(as sometimes occurs for CSVT during unrelated brain imaging) or, alternatively,
may present with signs and symptoms of chronic venous obstruction
or post-thrombotic syndrome (PTS) secondary to central venous or extremity
thrombosis, including limb pain and edema, dilated superficial collateral
veins, venous stasis dermatitis, or frank ulceration of the skin.
Diagnostic evaluation
Radiologic imaging
Historically, venography has been the gold standard for diagnosis of venous
thrombosis but limited by its invasiveness. In recent years, this modality
has experienced a diminishing role with the development of effective
noninvasive or minimally invasive radiologic imaging techniques. Radiologic
imaging is used not only to confirm the clinical diagnosis of VTE
but also to define the extent and occlusiveness of thrombosis. For suspected
DVT of the distal or proximal lower extremity, compression ultrasonography
with Doppler imaging typically is used for objective confirmation.
When the thrombus may affect or extend into deep pelvic or abdominal
veins, CT or MRI often is required. In suspected DVT of the upper extremity,
compression ultrasound with Doppler effectively evaluates the limb, but
other modalities (eg, echocardiography, CT, and MRI) are needed to disclose
involvement of more central vasculature (eg, right atrial thrombosis
and SVC thrombosis). In the case of asymptomatic nonocclusive extremity
DVT, conventional venography may be used as an alternative to CT or
MRI. To establish a diagnosis of DVT of the jugular venous system (such
as in suspected cases of the Lemierre syndrome) [12], compression ultrasound
with Doppler imaging typically is used.
PE in children commonly is disclosed by spiral CT or, alternatively, ventilation-perfusion
scan, the latter generally is suboptimal in cases wherein