role of sirolimus in treatment of microcystic , mixed lymphatic and vascular malformations

Conditions: Microcystic Lymphatic Malformation; Combined Vascular Malformation; Vascular Malformations

Summary: lympho-vascular malformations result from errors in embryologic vasculogenesis involving capillaries, veins, arteries, lymphatics, or a combination of these. infantile haemangiomas \& vascular malformations like : capillary malformations \& venous malformations : they increase in size and never regress on their own. \& they are generally present at birth, they enlarge in response to infection, hormonal changes or trauma . lymphatic malformations can be classified into macrocystic (cyst diameter \>1cm), microcystic (cyst diameter \<1 cm), or mixed , in macrocystic lymphatic malformations, surgery and sclerotherapy are effective . surgery of microcystic lymphatic malformations remains challenging due to their infiltrative nature \& sclerotherapy is often impossible. as especially large microcystic and mixed malformations are still a therapeutic challenge, pharmaceutical treatment as sirolimus is used in last years as main line of treatment with great efficacy.

lympho-vascular malformations result from errors in embryologic vasculogenesis involving capillaries, veins, arteries, lymphatics, or a combination of these. infantile haemangiomas \& vascular malformations like : capillary malformations \& venous malformations : they increase in size and never regress on their own. \& they are generally present at birth, they enlarge in response to infection, hormonal changes or trauma . lymphatic malformations can be classified into macrocystic (cyst diameter \>1cm), microcystic (cyst diameter \<1 cm), or mixed , in macrocystic lymphatic malformations, surgery and sclerotherapy are effective . surgery of microcystic lymphatic malformations remains challenging due to their infiltrative nature \& sclerotherapy is often impossible. as especially large microcystic and mixed malformations are still a therapeutic challenge, pharmaceutical treatment as sirolimus is used in last years as main line of treatment with great efficacy. sirolimus is a natural macrolide isolated from a bacteria strain of the streptomyces genus \& streptomyces hygroscopicus . it was initially used as an antibiotic and antifungal agent, subsequent studies have revealed impressive cytostatic, antiproliferative, and immunosuppressive properties . sirolimus not only prevents the growth of abnormal lymphatics but also induces the partial regression of lesions, without apparent effects on normal lymphatics .

Eligibility criteria:
inclusion criteria: * from age 6 months to 12 years , not before 6 months to complete their vaccination program \& maturation of hepatic enzymes . * patients diagnosed with microcystic \& mixed lymphatic malformations . * after failure of other lines of treatment as regard propranolol , steroid for infantile haemangiomas \& vascular malformations and lymphovascular malformations . * after failure of surgical excision \& injection of bleomycin of lympho-vascular malformations exclusion criteria: * macrocystic lymphatic malformations \& high flow vascular malformations like arterio-venous malformations . * an active infection that requires systemic treatment during the attack . * side effects of the drug as ( history of an allergic reaction to sirolimus or patients who develop severe allergic reaction to drug during treatment , hyperlipidemia , leucopenia , etc... ) * chronic liver or kidney disease or on chronic drug treatment as (steroids, interferon or chemotherapeutic agents) . * an immunodeficiency condition such as a human immunodeficiency viral infection or primary immunodeficiency disease. * patients who received drug less than 6 months duration .