Management of coagulopathy of KHE
Management of KMP is emergent as it may result in life-threatening
bleeding complications (Table 2). Although surgical resection can result
in cure, this is often unsafe due to coagulopathy and the extensive,
infiltrative nature of the KHE. Embolization has also been successful in
select cases28. However, medical management by a
hematologist is currently the standard in the US. There are no
randomized clinical trials for KHE and therefore most of the evidence
for treatment is through expert opinions or observational studies.
Historically corticosteroids have been successful in initial management
of KMP but is rarely successful as monotherapy29. Due
to adverse effects of prolonged corticosteroids in infants and young
children, the dose should be weaned rapidly once evidence of control of
coagulopathy. Vincristine in combination with corticosteroids has been
recommended in previous consensus statements to be the treatment of
choice but has recently been supplanted by sirolimus (plus
corticosteroids) as the first line choice17,30,31. A
randomized control trial of vincristine versus sirolimus was
discontinued early due to poor accrual primarily because of the provider
and family preference of sirolimus despite lack of rigorous evidence.
Vincristine is now primarily preferred for refractory or recurrent
cases. Topical sirolimus or tacrolimus have been shown in small studies
to be beneficial for superficial cutaneous
lesions32,33. Antiplatelet therapy such as aspirin or
ticlopidine in combination with vincristine have also shown
success34-37. Although it appears counterintuitive to
most hematologists to treat a patient with severe thrombocytopenia with
antiplatelet agents, this may be an option to prevent continued platelet
aggregation and activation as this is the primary trigger for the
coagulopathy. Antiplatelet therapy is used more frequently in European
centers and has not been widely adopted in North American centers.
However, for cases refractory to corticosteroids and/or sirolimus or
recurrent KMP upon tapering current medical therapy, antiplatelet
therapy should be considered as an adjuvant. Some reports of
fibrinolytic agents have been reported38, but we do
not currently routinely recommend these therapies.
Supportive care is critically important in the early management of KMP.
Platelet transfusions should be avoided unless indicated for severe
bleeding or prior to biopsy or resection17. Platelets
contain pro-angiogenic growth factor which may potentiate growth of the
vascular lesion. In addition, the transfused platelets will be further
trapped within the lesion resulting in further immediate growth and will
promote activation and consumption of coagulation
factors39,40. It is generally accepted that
cryoprecipitate or fresh frozen plasma be transfused for active bleeding
or prior to procedures if the fibrinogen is less than 100mg/dL. Routine
administration of cryoprecipitate for asymptomatic mild
hypofibrinogenemia is not indicated. Transfusion of packed red blood
cells is indicated for severe or symptomatic anemia17.