Disseminated intravascular coagulopathy in a child with extensive venous malformations.

Abstract

We wish to highlight the thromboembolic risk associated with venous malformations (VMs). In these patients, intra-lesional thrombosis can trigger the fibrinolytic cascade, indicated by elevated serum D-dimer levels and low fibrinogen.1 This is known as localised intravascular coagulation (LIC). Severe LIC can lead to life-threatening disseminated intravascular coagulopathy (DIC), with thromboembolism or bleeding, either spontaneously or as a result of infection, trauma, prolonged immobilisation, pregnancy or interventions to treat the VM.2 An 8-year old boy presented with an extensive VM affecting the entire left side of his body (Fig. 1). It was associated with disfigurement, limb length discrepancy and chronic pain. The serum D-dimer was above 20 µg/mL. Attempts to arrange multidisciplinary review and active management were unsuccessful. Sclerotherapy of the lower limb performed with low molecular weight heparin (LMWH) prophylaxis was complicated by the development of painful, palpable, propagating thrombosis in the abnormal large neck veins. A total of 1 mg/kg/day subcutaneous LMWH failed to resolve the clot or pain, and he presented to hospital. On admission, the coagulation profile was severely deranged, indicative of DIC (platelets 136 × 109/L (low); international normalised ratio (INR) 1.5 (high); D-dimer >20 µg/mL (high); fibrinogen 0.9 g/L (low)). He also had severe iron deficiency anaemia (haemoglobin (Hb) 74 g/L), thought to be dietary in origin. Doppler ultrasound revealed the extent of the cervical VM thrombosis propagating to, but not in to, the innominate vein. Computed tomography pulmonary angiogram excluded pulmonary embolism. Oral iron supplementation and subcutaneous LMWH 1.3 mg/kg BD were commenced, the latter achieving therapeutic anti-Xa levels of 0.5–1.0 units/mL. Over 5 months, the clot markedly diminished in size and his haematological and coagulation parameters normalised (Hb 123 g/L, platelets 153 × 109/L, INR 1.2, D-dimer 0.44 µg/mL, fibrinogen 3.6 g/L – all normal). LMWH was continued with monthly follow-up. He remained pain-free for the first time in his memory. This case illustrates the importance of identifying LIC related to extensive VMs and raises awareness of the potentially severe haematological complications that can occur, either spontaneously, or associated with interventional therapy. Treatment is required to prevent progression to DIC and associated complications, with the aim of normalising the D-dimer. The exact anticoagulation regime depends on a number of factors and needs to be individualised. LMWH is commonly used but recent case series suggest that oral sirolimus may also have a role.3 It is recommended that these complex patients be managed in a multidisciplinary setting. The input of a paediatric haematologist is essential.