Refractory Kasabach-Merritt phenomenon successfully treated with sirolimus, and a mini-review of the published work

Sirolimus for vascular anomalies in the first year of life: a systematic review

Evidence on effectiveness and safety of sirolimus in congenital vascular anomalies in infancy is lacking. We aim to systematically review the efficacy and safety of sirolimus in treating congenital VA in infancy. We searched for and included all studies evaluating sirolimus for VA in the first year of life. The primary outcome was effectiveness. The secondary outcome was safety. We included 84 case series and reports (172 participants). Sirolimus decreased the size of the VA in >50% of participants, most of whom had minor transient side effects, and 27% had no adverse effects at all. When categorized by age (<1 month, 1-5 months and 6-12 months), the effectiveness was similar in all age groups. Available evidence suggests that sirolimus is effective and well tolerated. The effectiveness of sirolimus should be evaluated in a well-designed randomized controlled or observational studies.

Cost and effectiveness comparison of sirolimus versus standard treatment in Kasabach-Merritt phenomenon: a real-world evidence study in Thailand

The conventional treatment of Kasabach-Merritt Phenomenon (KMP) consists of corticosteroids with vincristine/vinblastine or others. The aim of the study is to compare the first-year direct costs and effectiveness between sirolimus and conventional treatment. A retrospective case-control study of KMP patients was conducted at a mean age of 9 months (1 day to 12 years) between 2000 and 2022 from four tertiary centers in Thailand. The direct costs, hematologic and clinical complete response (HCR, CCR), hospitalization, length of stay, and complications were compared. Of 29 patients, 13 underwent sirolimus (four upfront and nine were refractory to the conventional). The first-year total cost had no statistically significant difference between sirolimus VS conventional treatment (8,852.63 VS 9,083.56 USD: p value: 0.94). The therapeutics achievement was the same in both HCR (244.75 VS 168.94 days; p value: 0.60) and CCR (419.77 VS 399.87 days; p value: 0.90). The subgroup analysis of the first-line sirolimus (n = 4) compared with the conventional (n = 25) showed a more reduced total cost (4,907.84 VS 9,664.05 USD; p value: 0.26) rendered net total cost of -4,756.21 USD per patient (cost saving). A more significant contrast of therapeutic achievement by reduction of both HCR (11.67 VS 224.20 days; p value: 0.36) and CCR (38.50 VS 470.88 days; p value: 0.04) was shown. The sirolimus had no difference in hospitalization, length of stay, and complications. Even though, it was unable to identify significant differences in cost-effectiveness. Sirolimus is suitable for all patients who have diagnosis of KMP either for rescue therapy or first-line treatment.

Retroperitoneal kaposiform hemangioendothelioma with kasabach-merritt phenomenon in children: A case report and review of the literature

Objective

To investigate the clinical features, diagnosis and treatment methods and prognosis of retroperitoneal Kaposiform hemangioendothelioma (R-KHE) in children.

Methods

The clinical data of an infant with R-KHE was retrospectively analyzed. Literature on R-KHE in pediatrics were retrieved in databases including Wanfang, CNKI and PubMed as of April 2022.

Results

A 1 month and 6 days female infant with R-KHE was reported. After the diagnosis was confirmed by biopsy and pathological examination, the patient was treated by interventional embolization, and a combined therapy with glucocorticoid, vincristine, sirolimus and propranolol. The patient has been followed up for 1 year and 2 months, and is still alive with tumor. Through literature search, a total of 15 children, together with the case in our report, were included. The main manifestations were diversity among those patients. 14 cases have combined Kasabach-Merritt phenomenon (KMP). 6 cases accepted surgery plus drug therapy. 4 cases accepted only surgery, and 4 cases only accepted drug therapy. While drug therapy plus radiotherapy were employed to 1 case. Improvement was observed in 11 cases, with significantly reduced tumor and survival with tumor. Tumor disappeared completely in 2 cases. While 2 cases suffered death.

Conclusion

R-KHE has diverse clinical presentations and non-specificity in symptoms and imaging examinations, and most cases accompanied with KMP. Methods for R-KHE treatment include surgical resection, interventional embolization and drug therapy. Close attention needs to be paid to the adverse reactions of the drug during the course of treatment.

Clinical Characteristics and Prognostic Factors in Pediatric Vascular Tumors

Background

The most common type of vascular tumors reported among children is hemangioma. The determinant factors to predict clinical outcomes among those patients were not well studied.

Objective

The study aimed to explore clinical characteristics and treatment approaches as well as associated prognostic factors of vascular tumors specifically in a pediatric population.

Methods

Pediatric patients with a confirmed diagnosis of vascular tumors between January 1, 2005 and December 31, 2017 were enrolled in this study. Clinical data includes initial clinical manifestations with associated complications, and diagnostic studies were used. To establish a diagnosis, the treatment modalities provided and final outcomes were retrospectively reviewed and analyzed.

Results

In all, 50 patients with a confirmed diagnosis of vascular tumors were enrolled. The median age at diagnosis was 11.5 years with equal gender distribution. The most common type of vascular tumor was hemangioma (n=41, 82%), followed by pyogenic granuloma (n=4, 8%), kapasiform hemangioendothelioma with Kasabach-Merritt phenomenon (n=2, 4%), infantile hepatic hemangioma (n=2, 4%), and juvenile nasal angiofibroma (n=1, 2%). The median age at diagnosis among patients with cutaneous vascular tumors (12.4 years) was significantly older than the age of those with visceral vascular tumors (1.3 years) witha P-value of 0.009. The mean size among patients with visceral tumors (7.46±4.84 cm) was significantly greater than the size among patients with cutaneous tumors (3.21±3.7 cm) with a P-value of 0.023. The size of the tumor was the only independent risk factor associated with clinical outcomes.

Conclusion

Age at diagnosis in cutaneous vascular tumors was significantly older than in visceral vascular tumors. Clinical outcomes are favorable among most patients and the size of the tumors is an independent risk factor associated with outcomes.

Kaposiform hemangioendothelioma with overlapping features of rapidly involuting congenital hemangioma and a delayed complication of necrotizing fasciitis

We report the case of a male infant born at term with kaposiform hemangioendothelioma (KHE) of the right forearm and coagulopathy. Our case was unusual as it involuted leaving subcutaneous atrophy and prominent veins, which are more commonly observed in rapidly involuting congenital hemangioma. At 3 years of age, the child developed recurrent superficial thrombophlebitis localized to the area where the KHE had regressed. Subsequently, he developed necrotizing fasciitis and thrombotic veins in the same location and group A streptococcal septic shock.

Successful treatment of an adult with Kasabach-Merritt syndrome using thalidomide, vincristine, and prednisone

Objective

Kasabach-Merritt syndrome is a rare disease that mainly occurs in infants and adolescents. It usually manifests as disseminated intravascular coagulation and severe bleeding, and is associated with high mortality. However, its low incidence and clinical rarity in adults mean that there is currently no well-verified treatment regimen for this disease. We report on an effective novel therapeutic regimen in a patient with Kasabach-Merritt syndrome.

Methods

A woman with Kasabach-Merritt syndrome presented with a recurrent subcutaneous mass and disseminated intravascular coagulation, and was treated with prednisone, vincristine and thalidomide.

Results

This treatment regimen successfully resolved the patient’s symptoms, with tumor regression. The patient remained disease-free after 6 years of follow-up.

Conclusions

Prednisone combined with vincristine and thalidomide may be an effective treatment for Kasabach-Merritt syndrome, but further studies are needed to verify the use of this regimen.

First Intracardiac Kaposiform Hemangioendothelioma in an Infant Resolved With Sirolimus: A Case Report

INTRODUCTION

Kaposiform hemangioendothelioma (KHE) is a rare and aggressive vascular tumor that can be associated with a consumptive coagulopathy and thrombocytopenia (Kasabach-Merritt phenomenon). Only one case of an intracardiac KHE has been reported which was treated with surgical excision and then expectant management.

CASE PRESENTATION

We present a patient with an intracardiac KHE which presented as a large mass surrounding the atria, pulmonary veins, superior vena cava, and infiltrating the atrial septum with moderate compression of the superior vena cava and mild compression of the pulmonary veins. This tumor clinically presented as persistent tachypnea and was unresponsive to conventional therapy with vincristine and steroids but responded dramatically to Sirolimus with almost complete regression on follow-up.

CONCLUSIONS

None of the current treatments for KHE, alone or in combination therapy have been found to be effective in a uniform or reproducible manner. Well designed, preferably randomized trials are required for a better understanding of the appropriate dosage and duration as well as response to treatment and a consensus of first and second line therapies.

Successful Management of Kaposiform Hemangioendothelioma with Long-Term Sirolimus Treatment: a Case Report and Review of the Literature

Background

Kaposiform Hemangioendothelioma (KHE) is a rare vascular tumour of the infancy and the first decade of life. It is locally aggressive and potentially life threatening when associated with consumptive coagulopathy, known as Kasabach-Merritt syndrome (KMS). No consensus or guideline for the therapy has been reached because of the lack of prospective trials, and the different standard care suggestions are based on retrospective case series.

Case report

We report the case of a 9-month-old male with KHE and KMS in which the initial response, obtained with prednisone and vincristine, was subsequently consolidated and strengthened by long-term treatment with sirolimus, a mTOR inhibitor. A summary of the published data is presented as well.

Conclusions

The inhibition of mTOR pathway represents the most important therapeutic innovation introduced in the last few years for KHE. Our case shows the effectiveness and good tolerance of long-term therapy with sirolimus.

Successful Everolimus Treatment of Kaposiform Hemangioendothelioma With Kasabach-Merritt Phenomenon: Clinical Efficacy and Adverse Effects of mTOR Inhibitor Therapy

Kasabach-Merritt phenomenon (KMP) is a life-threatening consumptive coagulopathy associated with underlying kaposiform hemangioendothelioma (KHE) in infancy. We describe the case of a 3-month-old girl with KHE complicated by KMP who responded dramatically to treatment with everolimus, a mechanistic target of rapamycin (mTOR) inhibitor. Immunohistochemical expression of mTOR was found in the KHE biopsy specimens, which may explain the improvement of KMP and reduction in KHE tumor size with mTOR inhibitor treatment. This effective use of everolimus may shed light on the emerging role of mTOR signaling in the development and pathogenesis of KHE and KMP.

Metastatic Angiosarcoma with Kasabach-Merritt Syndrome Responsive to Gemcitabine and Vinorelbine after Failure of Liposomal Doxorubicin and Paclitaxel: A Case Report

Kasabach-Merritt syndrome (KMS) describes a consumptive coagulopathy associated with certain vascular tumors. It is thought that platelets are destroyed as they circulate through the aberrant endothelial surfaces associated with these tumors. Most published literature describes infants with kaposiform hemangioendothelioma, but a similar syndrome can complicate angiosarcoma in adults. This report describes a man with metastatic angiosarcoma arising in the scalp in whom disease progression was complicated by profound thrombocytopenia consistent with KMS. His disease and associated KMS had progressed previously through paclitaxel and then through liposomal doxorubicin. It did not respond to paclitaxel and bevacizumab, but responded almost completely to chemotherapy with gemcitabine and vinorelbine. Six months later, progression through ongoing chemotherapy then responded to chemotherapy with cyclophosphamide and sirolimus.