Clinical analysis of kasabach-merritt syndrome in 17 neonates

From January 2007 to January 2012, 17 patients with giant hemangioma who were eventually diagnosed with KMS were admitted to the Department of Neonates at Guangzhou Women and Children’s Medical Center, China.

The diagnostic criteria for KMS were as follows: (1) hemangioma of the skin or internal organs; (2) thrombocytopenia and consumptive coagulopathy; (3) hemangioma confirmed by B-mode ultrasonography, color Doppler flow imaging, computed tomography (CT), or magnetic resonance imaging (MRI); (4) other causes for the abnormalities excluded, such as hypersplenism or idiopathic thrombocytopenic purpura.

The diagnostic criteria for disseminated intravascular coagulation (DIC) followed overt DIC criteria by ISTH (Table 1).

Written informed consents were obtained from the patients for publication of this case report and any accompanying image. Copies of the written consents are available for review by the Editor of this journal.

The research has been approved by Guangzhou Women and Children’s Medical Center’s appropriate ethics committee.

The appearances, characteristics, and complications of hemangioma in the 17 neonates with KMS were summarized and analyzed.

The 17 neonates with KMS were treated with steroid therapy, arterial embolization, and vincristine, depending on their individual responses to treatment.

The 17 patients with KMS included 13 males and 4 females. Their age at admission ranged from 17 hours to 28 days. One patient was born prematurely (34⁺⁵ weeks gestation), and the remainder were born at term. The birth weight ranged from 2300 g to 4000 g.

Of the 17 patients, 4 had visceral hemangiomas, including 1 patient with multiple cutaneous hemangiomas (more than 20 hemangiomas of different sizes) and multiple hepatic hemangiomas, 1 patient with a right submandibular racemose hemangioma, 1 patient with a giant hepatic hemangioma, and 1 patient with an intracranial hemangioma. The remaining 13 patients had cutaneous hemangiomas only. The locations of cutaneous hemangiomas varied widely. Cutaneous hemangiomas appeared as violet or dark red lesions with obvious swelling, increased tension, slightly increased skin temperature, unclear boundaries, and a firm or hard texture (Figure 1). Seven patients had large numbers of bleeding points and ecchymosis. In one case, right submaxillary ecchymosis and thrombocytopenia were detected during the neonatal period, leading to a diagnosis of thrombocytopenic purpura at the local hospital. The patient was transferred to Guangzhou Women and Children’s Medical Center for treatment of a pericardial effusion. CT showed a racemose hemangioma of the pericardium, and B-mode ultrasonography showed a right submaxillary subcutaneous hemangioma. In another case, the patient was jaundiced at admission, and the right eye protruded further than the left eye. The patient had a black rash on his right upper eyelid, and a large amount of ascites. Brain MRI showed a hemangioma arising from a vascular malformation in the right cavernous sinus and right eye socket.

Laboratory examination findings showed a mean platelet count of 31.1 ± 21.7 × 10⁹/L (range 2–119 × 10⁹/L), hemoglobin concentration of 94.1 ± 21.1 g/L (range 66–128 g/L), prothrombin time of 28 ± 5.6 s (range 13–38 s) with a prolonged prothrombin time in 15 patients, thrombin time of 18 ± 3.6 s (range 15–28 s) with a prolonged thrombin time in 5 patients, activated partial thromboplastin time of 51 ± 5.8 s (range 40–72 s) with a prolonged activated partial thromboplastin time in 8 patients, and fibrinogen level of 0.8 ± 0.37 mg/dL (range 0.34-1.8 mg/dL) with a low fibrinogen level in 15 patients. Two patients met the diagnostic criteria for DIC.

The 17 patients received sequential combined therapy. The initial therapy was supportive. Six patients with a platelet count of <20 × 10⁹/L received apheresis platelet infusions. Eight patients with a fibrinogen level of <1.0 mg/dL received cryoprecipitate infusions. Intravenous dexamethasone 1 mg/kg/day was administered simultaneously as first-line drug treatment. The platelet count started to increase at 3–8 days after the start of treatment in seven patients, reaching a normal value at 16–28 days. Coagulation function improved, and no bursting or bleeding of hemangiomas was observed. After the platelet count returned to normal, we evaluated the effectiveness of the therapeutic regimen. If the treatment was effective, it was gradually withdrawn over the following 1–2 months, after which patients were discharged on medication. The six patients who responded well to steroid therapy were regularly followed up at the hospital. In three patients, the platelet counts remained normal for the following year. The hemangiomas did not enlarge or bleed, and regressed within 1–2 years. In the other three patients, the platelet counts subsequently decreased (at 30 days, 3 months, and 5 months after treatment), and they were re-admitted to hospital and underwent arterial embolization. No relapses were observed over the following year.

The other 11 patients received supportive treatment and steroid therapy for 10 days, but their platelet counts remained low, and the hemangiomas bled in some cases. One patient discontinued therapy because of the severity of disease and financial difficulty. The remaining 10 patients underwent arterial embolization. The femoral artery was cannulated under general anesthesia using the Seldinger technique. A 3-F or 4-F cannula was introduced and the patient was heparinized. A 3-F or 4-F Cobra catheter was introduced for arteriography, and was advanced to the feeding artery of the hemangioma. Arterial embolization was performed with a mixture of bleomycin A5 (8–12 mg/m²), iodinated oil (2 mL), and dexamethasone (2 mg). After removal of the catheter, the bleeding was controlled by direct pressure for 15 min, and a pressure dressing was applied (Figure 2). Six patients were given dexamethasone after arterial embolization. The platelet counts increased at 2–5 days after embolization, and reached normal levels at 10–16 days. The coagulation function was improved, and no bursting or bleeding of hemangiomas was observed. Patients were followed up regularly after embolization. Only one patient developed recurrence at 5 months after embolization, and underwent repeat embolization and vincristine chemotherapy (1 mg/m² weekly). In the remaining four patients, the platelet count decreased at 1 week after surgery. These patients were treated with vincristine chemotherapy 1 mg/m² weekly, resulting in improvement. Three of these patients did not relapse during a year of follow-up, and the other patient died of severe disseminated intravascular coagulation. In one patient with intracranial hemangioma, the hemangioma regressed during 2 years of follow-up (Figure 3). One patient developed a fever during treatment, and one developed gastrointestinal adverse effects. No cases of bone marrow depression or neurotoxicity were observed.