Kasabach-Merritt Syndrome

Characterized by the association of a vascular tumor with thrombocytopenia and coagulopathy. Histologically, it is either a kaposiform hemangioendothelioma or a tuft angioma, not a hemangioma.

Hemangioma-Thrombocytopenia Syndrome.

Approximately 300 cases have been reported in the literature since 1940. Slightly more frequent in females. No racial predilection.

Unknown; seems to be more frequent in Asia.

Ecchymotic tumor develops on a vascular lesion; it usually starts in the neonatal period and grows very quickly; tumoral growth is accompanied by thrombocytopenia and hypofibrinogenemia. This disseminated intravascular coagulation (DIC) picture is secondary to entrapment of platelets within the vascular tumor.

The triad of thrombocytopenia, coagulopathy, and a vascular tumor should be highly suggestive.

Enlarging hemangioma-like lesion, mainly cutaneous (especially on the extremities) but also visceral. DIC (decreased platelets and fibrinogen, presence of increased d-dimers). Often inoperable. Treatment options: vincristine, interferon-α, steroids, ticlopidine with aspirin, or radiotherapy. Untreated Kasabach-Merritt syndrome has a 10 to 37% mortality rate.

Examine for airway involvement. Check complete blood count (platelet count), coagulation profile, bleeding time, and cross-match for blood even for minor surgical procedures.

Potential difficult airway if oropharyngeal or neck involvement is present. Anticipate the need for blood products to treat anemia and/or coagulopathy. Do not transfuse platelets because they will immediately be trapped within the tumor with an ensuing increase in size. Effect of chemotherapy on the cardiac and respiratory system must be considered.

No specific pharmacological implications with this condition; however, patients treated with chemotherapy and corticosteroids (perioperative stress dose) must be prepared for anesthesia accordingly. Avoid nonsteroidal antiinflammatory drugs secondary to their effects on platelets.

Congenital Hemangiomas: Share many similarities with Kasabach-Merritt syndrome, but without the coagulation disorders; they usually regress between 5 and 9 years of age.

Klippel-Trenaunay Syndrome: Congenital arteriovenous malformation usually located on a single extremity resulting in skeletal and soft tissue hypertrophy.