Effectiveness of sirolimus in the treatment of complex lymphatic malformations: Single center report of 56 cases

Background: Lymphatic malformations are common congenital vascular lesions. Neither surgical resection nor other surgical treatments have been found to be effective for invasive cases. Recent research has suggested that sirolimus is effective in treating complex lymphatic malformations (LMs). We aimed to evaluate the effectiveness and safety of oral sirolimus for children living with LMs in our hospital. Methods: Fifty-six cases of complex LMs treated with sirolimus were collected from Shanghai Children's Medical Centre between June 2016 and March 2019. All cases were confirmed either by pathology (44) or enhanced MRI (12). Following informed consent, sirolimus 0.8 mg/m(2) bid was administered orally to participants and maintained at a trough concentration of 10-15 ng/ml. Children's ages at diagnosis were neonate to 16 years (mean 44.3 months). All children were followed up for 5 to 30 months, with a mean of 16.8 months. Results: During the follow-up period, blood, liver and kidney function as well as disseminated intravascular coagulation was regularly reviewed in all 56 children. Enhanced MRI was regularly performed to evaluate therapeutic effects. Total effective rate (complete response or partial response) of LMs was 89.3% (50/56). No serious adverse reactions were found. Conclusion: This study suggests that sirolimus is effective and tolerable for decreasing lesions in children with complex LMs, leading to fewer and more tolerable side effects. There is no need to pursue an excision rate to reduce unnecessary operative complications since adjuvant sirolimus therapy modifies the complex LMs clinical appearance and alleviates their symptoms. Type of study: Clinical research. Level of evidence: Level IV. (C) 2020 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).