Successful Treatment of a Complex Vascular Malformation With Sirolimus and Surgical Resection

Medical Therapeutics for the Treatment of Vascular Anomalies: Part 3

The discovery of inherited and somatic genetic mutations, along with advancements in clinical and scientific research, has improved the understanding of vascular anomalies and changed the treatment paradigm. With the aim of minimizing the need for invasive procedures and improving disease outcomes, molecularly targeted medications and anti-angiogenesis agents have become important as both adjuncts to surgery, and increasingly, as the primary treatment of vascular anomalies. This article highlights the commonly used and emerging therapeutic medications for nonmalignant vascular tumors and vascular malformations.

Effects of sirolimus in the treatment of unresectable infantile hemangioma and vascular malformations in children: A single-center experience

OBJECTIVE

Recently, sirolimus has emerged as a safe and effective treatment modality for unresectable vascular lesions. In the present study, we investigated the effectiveness and safety of sirolimus from our early experience with patients with unresectable vascular anomalies.

METHODS

The medical records and radiologic images of all patients with unresectable vascular anomalies treated with sirolimus at our center from January 2018 to November 2019 were retrospectively reviewed. All patients were administered oral doses of sirolimus 0.8 mg/m² every 12 hours as the initial dose, followed by maintenance of a target serum concentration (5-10 ng/mL) with therapeutic drug monitoring.

RESULTS

Six patients with unresectable vascular anomalies were treated with sirolimus for ≥10 months. Their median age at the initiation of sirolimus treatment was 17 months (range, 8-67 months). The median duration of treatment was 13 months (range, 10-16 months). One patient had a good response, four had an intermediate response, and one had no response to sirolimus therapy. None of the patients had discontinued sirolimus therapy because of adverse effects.

CONCLUSIONS

Sirolimus can be used effectively and safely for patients with unresectable vascular anomalies. However, further prospective studies are warranted to evaluate the long-term effects of sirolimus and clarify the indications for early intervention.

A narrative review of the role of sirolimus in the treatment of congenital vascular malformations

OBJECTIVE

Vascular malformations arise from defects in the morphologic development of the vascular system and can have an impact on quality of life and/or lead to severe complications. To date, vascular malformations are frequently managed by invasive techniques, after which recurrence is common. Sirolimus, a downstream inhibitor of the phosphatidylinositol 3 kinase/AKT pathway and best known for its immunosuppressive effect, has been used off-label for lesions for which approved therapies were associated with unsatisfactory results or recurrence. The aim of this study was to review the available data on the effect of sirolimus on the size and symptoms of different types of malformations and to summarize the main safety issues.

METHODS

A literature search in Pubmed, Embase, Web of Science, and SCOPUS was performed. Case reports, case series, and clinical trials evaluating the effect of sirolimus in vascular malformations were eligible for this review. Fully terminated studies published between January 2010 and May 2019 reporting an evaluable response on size and/or symptoms were included. Relevant data on lesion size, symptoms, side effects and duration of treatment were extracted as reported in the study. Additionally, we reported 10 unpublished cases who were treated in UZ Leuven.

RESULTS

The literature review included 68 articles, describing 324 patients. The median duration of therapy was 12 months (range, 1-60 months). After 6 months of treatment, the size of the malformation had at least decreased in 67% of patients with common venous malformations (VM), in 93% of patients with blue rubber bleb nevus syndrome and in all patients with verrucous VM. The size of lymphatic malformations improved in more than 80% of the patients, even in the case of extensive involvement such as in Gorham-Stout disease and generalized lymphatic anomaly. In addition, the majority of patients with syndromic vascular malformations experienced a decrease in size and reported symptoms improved in almost all patients, regardless of the type of malformation. Side effects were common (53%) but usually mild; mucositis and bone marrow suppression were the most common. Regrowth or recurrence of symptoms occurred in 49% of patients who discontinued treatment. Comparable effects were seen in our own patients.

CONCLUSIONS

This review shows that sirolimus is effective in decreasing the size and/or symptoms of particularly lymphatic malformations as well as VMs. Although common, side effects were usually mild. Nevertheless, clinical trials are needed to confirm the safety and effectivity of sirolimus and to identify the required serum levels and duration of treatment.

Efficacy and safety of sirolimus in the treatment of vascular malformations: A protocol for systematic review and meta-analysis

BACKGROUND

The pathophysiologic of vascular malformations is still unclear, and the treatment of vascular malformations is a challenge. With improvement in the understanding of pathogenesis of vascular malformations, sirolimus has been a promising and effective treatment. As so far, there is absent convincing evidence to confirm the efficacy of sirolimus for vascular malformations. The purpose of this study was to evaluate the effectiveness and safety of sirolimus in the treatment of vascular malformations.

METHODS

The literatures about the management of vascular malformations with sirolimus would be searched from databases of MEDLINE, EMBASE, PubMed, Web of Science, Clinicaltrials.org., Cochrane Library, China Biology Medicine Database (CBM), Wan Fang Database, China National Knowledge Infrastructure Database (CNKI), and VIP Science Technology Periodical Database. We will search each database from inception or 1995 to August 20, 2020. Two researchers worked independently on literature selection, data extraction and quality assessment. The efficacy and safety of sirolimus in the treatment of vascular malformations were the main outcomes. Adverse events after sirolimus were evaluated as the secondary outcomes. The included studies will be analyzed by Review Manager 5.3. If the results are applicable, meta-analysis would also be performed.

RESULTS

The study will evaluate the efficacy and safety of sirolimus in the treatment of vascular malformations based on current evidence.

CONCLUSION

The conclusion of this study will provide more reliable, evidence-based data for the use of sirolimus in the treatment of vascular malformations.

PROSPERO REGISTRATION NUMBER

CRD42020167881.

Therapeutic evaluation of sclerotherapy for limb venous malformations: A case series

OBJECTIVES

To examine three different methods for evaluating the effect of percutaneous sclerotherapy on limb venous malformations in a series of patients with a relatively long follow-up.

METHOD

The study was a retrospective study.

RESULTS

Thirty-eight patients treated with percutaneous sclerotherapy underwent sclerotherapy, with a median number of sessions of 4 (range, 1-10). They were followed up for 1-60 months (average 12.5 months). The kappa between clinical manifestations and Doppler ultrasound was 0.684 (P < 0.001). The kappa between clinical manifestations and magnetic resonance imaging was 0.217 (P = 0.006). The kappa between Doppler ultrasound and magnetic resonance imaging was 0.323 (P < 0.001). The rate of grade IV patients evaluated by clinical manifestations was significantly higher than that by Doppler ultrasound and magnetic resonance imaging.

CONCLUSIONS

Magnetic resonance imaging is the gold standard for VM imaging. Its consistency with clinical examination and Doppler ultrasound is poor, and Doppler ultrasound and clinical examination could be more appropriate for follow-up imaging after sclerotherapy.

The use of rapamycin to treat vascular tumours and malformations: A single-centre experience

Objectives

To assess the safety and efficacy of rapamycin in treating children with vascular tumours and malformations.

Study design

We performed a retrospective review at a large tertiary care paediatric centre to assess the efficacy and safety of using rapamycin to treat vascular tumours and malformations. Response to therapy was defined by patient-reported symptom improvement, radiological reduction in size of lesions, and/or improvement of laboratory parameters.

Results

Forty-two patients (7 with vascular tumours and 35 with vascular malformations) have been treated with rapamycin. Despite 33 of 42 patients being diagnosed in the first year of life, the median age of initiating rapamycin was 11 years. Of the 38 children treated for a minimum of 4 months, 29 (76%) exhibited a clinical response. Twenty-one patients had follow-up imaging studies and of these, 16 (76%) had radiographic decrease in lesion size. Median time to demonstration of response was 49 days. All five children with vascular tumours and all three children with vascular malformations under the age of 4 years showed a clinical response. Response rate was lower for children ≥ 4 years of age (0/2, 0% for vascular tumours; 21/28, 75% for vascular malformations). No patient experienced an infection directly related to rapamycin or discontinued rapamycin due to toxicity.

Conclusions

Rapamycin is safe and efficacious in most children with select vascular tumours and malformations. Young children appear to respond better, suggesting that early initiation of rapamycin should be considered.