Pain management
Treatment with compression is usually the first intervention for pain
secondary to a vascular malformation. Subsequently, systemic treatment
of pain is targeted at associated phleboliths and localized intra-lesion
thrombosis. Aspirin, an antiplatelet agent, was initially used and shown
to be helpful in a subset of patients41. With an
increased severity in pain and evidence of phleboliths, LMWH is commonly
prescribed. In recent years, newer oral anticoagulants such as
rivaroxaban have become available. Rivaroxaban, a direct factor Xa
inhibitor can prevent and treat venous thrombosis. At this time, all
anticoagulants used in the standard of care for pediatric population are
prescribed without formal FDA-approved indication. By directly
inhibiting the coagulation factors, it should have clinical efficacy
equivalent to heparins. Several case reports of pediatric and adult
patients with slow-flow vascular malformations refractory to LMWH had
improvement in LIC and pain from rivaroxaban42-44.
Sirolimus therapy has also been shown to improve pain and LIC in some
patients with slow-flow vascular malformations15,30.
VTE prophylaxis and management of pain
Management for VTE risk and pain due to microthrombi secondary to LIC
begins with conservative management utilizing compression garments to
help flow return, decrease stagnant blood flow and maintain integrity of
the flaccid vessel45,46. The approach in our practice
is that treatment for pain should be considered if there is evidence of
LIC (D-dimer > 2 times ULN) and/or one or more of the
following: decreased fibrinogen, decreased platelet count, presence of
phleboliths, or localized pain. Anticoagulation may be initiated at the
following recommended doses according to our practice:
- LMWH 0.5 mg/kg/dose every 12 hours, increase to 1 mg/kg/dose every 12
hours at 2 weeks if no or minimal benefit
OR
- Rivaroxaban 10 mg PO daily, increase to 15 mg at 2 weeks if no or
minimal benefit (for patients >50kg and 15 years of age)
Duration of anticoagulation can vary from a minimum of 2 weeks to
long-term treatment. Follow up is recommended at 2 weeks, 4 weeks, 12
weeks and every 3 months until off anticoagulation. This approach is
currently being investigated in a multi-institutional prospective
clinical trial. [Figure 3]