Early Adjuvant Medication With the mTOR Inhibitor Sirolimus in a Preterm Neonate With Compressive Cystic Lymphatic Malformation

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.

Sirolimus for Pediatric Cervicofacial Lymphatic Malformation: A Systematic Review and Meta-Analysis

OBJECTIVE

This study is a systematic review and meta-analysis of the efficacy and safety of sirolimus in the management of pediatric cervicofacial lymphatic malformations (LMs).

DATA SOURCES

EMBASE, Medline, Scopus, and Cochrane databases were searched, along with the reference list of all included articles.

REVIEW METHODS

The study protocol was registered with PROSPERO and a systematic literature search strategy was designed and conducted with the aid of a medical librarian. All studies including case reports were included, with pooled analysis of raw data. A meta-analysis was conducted of magnetic resonance imaging (MRI), clinical, and airway outcomes.

RESULTS

Thirteen case series and five individual case reports were included. Meta-analysis showed 78% (95% CI 57%-94%) of 62 patients had a reduction in LM volume, on MRI criteria, by 20% or more, and 32% (95% CI 11%-57%) had a reduction of 50% or more. Further meta-analysis showed 97% (95% CI 88%-100%) of 78 patients reported some clinical improvement on sirolimus. Sirolimus may be of particular value in management of airway LMs; out of 27 tracheostomy-dependent patients, meta-analysis showed 33% (95% CI 1%-78%) were decannulated after starting sirolimus. Individual patient meta-analysis on 24 individuals showed a statistically significant better response to sirolimus when initiated under the age of 2 years.

CONCLUSION

This review and meta-analysis support the efficacy of sirolimus in pediatric LMs of the head, neck, and airway. A large multi-center trial is needed to further explore its role and limitations. Laryngoscope, 134:2038-2047, 2024.

Efficacy of sirolimus in children with lymphatic malformations of the head and neck

Purpose

Children with extensive lymphatic malformations of the head and neck often suffer from functional impairment and aesthetic deformity which significantly affect the quality of life and may be life-threatening. Treatment with sirolimus has the potential to improve symptoms and downsize lymphatic malformations. This systematic review summarizes the current information about sirolimus treatment of lymphatic malformations of the head and neck in children, its efficacy and side effects.

Methods

A systematic search of the literature regarding studies on sirolimus treatment of children with lymphatic malformations of the head and neck was performed in PubMed, Embase, and Google Scholar up to July 2021 with the search terms “lymphatic malformation”, “lymphangioma”, “cystic hygroma”, “low-flow malformation”, “sirolimus”, “rapamycin”, “mTOR inhibitor” and “children”.

Results

In all, 28 studies including 105 children from newborn to 17 years treated with sirolimus for lymphatic malformations of the head and neck were analyzed. The most frequent initial dose was 0.8 mg/m² per dose, twice daily at 12-h interval. The target blood level differed between studies, 10–15 ng/mL and 5–15 ng/mL were most often used. More than 91% of the children responded to sirolimus treatment which lasts from 6 months to 4 years. Typical side effects were hyperlipidemia, neutropenia and infections.

Methods

Sirolimus could be an effective treatment for children with large complicated lymphatic malformations of the head and neck. As not all patients will benefit from treatment, the decision to treat sirolimus should be made by a multidisciplinary team.

Robotic-assisted laparoscopic management of mesenteric cysts in children

BACKGROUND

Mesenteric cysts (MCs) are rare intra-abdominal masses in children, and laparoscopic complete cyst resection is still difficult. This study reviewed our experience in diagnosing and managing MCs at our center, focusing on the clinical characteristics of MCs and the effectiveness of robotic-assisted laparoscopic surgery.

METHODS

We conducted a retrospective analysis of the records of all patients diagnosed with MCs and managed with robotic-assisted laparoscopic surgery at our center between February 2021 and August 2022. We analyzed demographic characteristics, clinical manifestations, preoperative imaging data, surgical methods, postoperative complications, and final outcomes.

RESULTS

Totally, 12 consecutive patients with a mean age of 5.81 ± 3.02 years were admitted. The most common symptom was abdominal pain (58.33%). Eight patients were associated with cyst complications, including five cases of infection, two cases of volvulus, and one case of hemorrhage. The mean size of cysts was 8.39 ± 5.91 cm. The cysts were located in ileal mesentery in eight cases, lesser curvature of the stomach in two cases, and colon mesentery in two cases. Solely cyst excision was performed in eight cases, and bowel en bloc resection of the cyst in four cases. Robotic-assisted laparoscopic surgery was performed successfully in all patients, without conversion. The mean operation time was 106.17 ± 33.74 min. Pathological results reported lymphangioma or lymphatic malformation in all patients. Two cases of chylous leakage were treated conservatively, and no complications of peritoneal infection, anastomotic leakage, and recurrence were observed.

CONCLUSIONS

Mesenteric cysts should be removed promptly once the diagnosis is confirmed to avoid cyst complications. For uncomplicated mesenteric cysts, laparoscopic cyst excision, or cyst excision with bowel resection can be effectively performed in children, especially under the robot system.

Intermittent Administration Regimen of Sirolimus for Refractory Cervicofacial Lymphatic Malformation

BACKGROUND

The cervicofacial lymphatic malformations (LMs) often have poor outcomes due to their microcystic component and diffuse infiltration. Mostly, traditional treatments are inadequate for these refractory cases. Recent researches have shown that sirolimus is effective in the treatment of complicated LMs, however, there is still no standard strategy.

OBJECTIVE

To evaluate the efficacy and safety of intermittent oral sirolimus in treating refractory cervicofacial LMs as a second-line treatment.

METHODS

Fifteen pediatric patients of refractory cervicofacial LMs were retrospectively analyzed in this study. All the cases had received traditional therapy before, but could not completely control the symptoms and eliminate lesions. As a remedy, sirolimus was then proceeded with an intermittent administration regimen, that is 3 continuous months as a course and started the next course after 1 month interval. The clinical characteristics, imaging data of patients, the changes in the signs and symptoms observed, and associated adverse effects were collected and analyzed.

RESULTS

The patients initiated sirolimus therapy at the average age of 2.3 years (range 28 days-8 years 9 months). At the end point of the study, 2 patients remained on sirolimus in continuous courses of treatment. Of 13 patients who withdrawn therapy, 4 had restarted due to recurrence of symptoms and re-expansion of LMs. All patients demonstrated reduction in residual LMs and complete disappearance of symptoms during treatment, and 2 patients with complete resolution on imaging. Toxicity was tolerant in this series. There was no patient develop opportunistic or systemic bacterial infection.

CONCLUSIONS

Sirolimus is commended as a second-line treatment to treat intractable cervicofacial LMs after failure of traditional therapy. The intermittent administration regimen is efficacious to completely control symptoms and partially reduce residual lesions with good tolerance and limited side effects.

Antiproliferative therapy with sirolimus and propranolol for congenital vascular anomalies in newborns (Case reports)

We present a series of four newborns diagnosed with complicated congenital vascular anomalies, with different localization: Congenital lymphatic malformation (CLM) on the left hemithorax extending on the left upper limb; congenital hepatic hemangioma (CHH) with important complications in the first 7 weeks of life; Kaposiform hemangioendothelioma (KHE) of the left lower limb complicated with Kasabach Merritt phenomenon (KMM) and most probable diffuse capillary malformation with overgrowth (DCMO). All patients were treated with combined antiproliferative therapy with sirolimus and propranolol. The initial dose of sirolimus was 0.45-0.5 mg/m² with doses adjusted according to plasmatic levels. Therapeutic intervals of sirolimus were considered at plasmatic levels of 7-12 ng/ml. Our aim was to use the lowest therapeutic dose in order to avoid possible side effects. Propranolol was initiated in doses of 0.5-1.0 mg/kg/day and was increased up to 3.0 mg/kg/day depending on tolerability. Following two months, every patient showed a marked reduction in the size of the mass, improvement in overall appearance or even calcification in the liver vascular tumor. No patient showed life threatening side effects to the treatment. Hypertriglyceridemia was the only side effect noted in all patients. This is in accordance with several international studies, which try to demonstrate the importance of sirolimus in neonatal vascular malformations in monotherapy or combined with different drugs.