Late sequelae and long-term outcomes of vascular anomalies

Ablation of Venous Malformations by Photothermal Therapy with Intravenous Gold Nanoshells

Venous malformations (VMs) consist of hugely enlarged and dysmorphic veins. These lesions cause significant disfigurement, pain, and complications such as bleeding and coagulopathy. Pharmacotherapy for the treatment of VMs has limited efficacy and potentially limiting toxicity. Current treatment for patients with VMs entails life-long pharmacotherapy or surgical procedures. Here we explored whether intravenously administered agents can be used to destroy VMs by photothermal therapy (PTT), using gold nanoshells (AuNSs) that generated heat following irradiation with near-infrared (NIR) light. In a murine model of VMs, intravenous AuNSs accumulated within the VMs. Irradiation of the VMs induced marked regression and even elimination. Nanoparticle-based photothermal therapy can provide effective therapy for VMs, which are otherwise relatively refractory to treatment.

Targeting Nanoparticles to Bioengineered Human Vascular Networks

Pharmacotherapy of vascular anomalies has limited efficacy and potentially limiting toxicity. Targeted nanoparticle (NP) drug delivery systems have the potential to accumulate within tissues where the vasculature is impaired, potentially leading to high drug levels (increased efficacy) in the diseased tissue and less in off-target sites (less toxicity). Here, we investigate whether NPs can be used to enhance drug delivery to bioengineered human vascular networks (hVNs) that are a model of human vascular anomalies. We demonstrate that intravenously injected phototargeted NPs enhanced accumulation of NPs and the drug within hVNs. With phototargeting we demonstrate 17 times more NP accumulation within hVNs than was detected in hVNs without phototargeting. With phototargeting there was 10-fold more NP accumulation within hVNs than in any other organ. Phototargeting resulted in a 6-fold increase in drug accumulation (doxorubicin) within hVNs in comparison to animals injected with the free drug. Nanoparticulate approaches have the potential to markedly improve drug delivery to vascular anomalies.

A multidisciplinary approach to management of abdominal lymphatic malformations

BACKGROUND/PURPOSE

Abdominal lymphatic malformations (LM) are a rare subset of vascular anomaly caused by abnormal development of the lymphatic system. They are classified as macrocystic, microcystic or combination macrocystic and microcystic. Surgical resection, percutaneous sclerotherapy, and medical therapy are all employed to treat these complex and often symptomatic lesions. No standardized treatment algorithm exists currently. The purpose of this study was to establish a multidisciplinary treatment approach to abdominal LMs.

METHODS

A retrospective observational study was conducted from 2013 to 2019 on patients with abdominal LMs at a single tertiary children's hospital vascular anomalies center. Demographics, imaging, and treatment modality were recorded. Clinical and/or radiographic response to the primary treatment modality as well as complications was the outcomes measured.

RESULTS

Nineteen patients (12 macrocystic, 5 microcystic and 2 combined) were identified, with a median age at diagnosis of 2.2 years (range 0.1-20.8 years). Sclerotherapy was the most common primary treatment, followed by surgical resection and sirolimus. No difference in clinical response (p = 0.58) or complications (p = 0.31) was observed based on primary treatment or subtypes.

CONCLUSIONS

Based on our institutional experience, we propose an LM subtype-based treatment algorithm for abdominal LMs. It employs a multidisciplinary approach, and results in satisfactory patient outcomes with minimal complications.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Infantile haemangioma: 5-year experience at the vascular anomaly clinic

Background

Infantile haemangiomas (IH) represent a common benign vascular tumour affecting the paediatric population. Infantile haemangiomas are characterised by a natural history differentiating it from other vascular anomalies. After a transient proliferative phase in early infancy, the tumour passes through a plateau phase before going into spontaneous involution. In this report, we tried to share our experience over the last 5 years in managing cases presenting with IH at a specialised vascular anomaly clinic.

Main body of abstract

This report included cases of IH who were attending the vascular anomaly clinic during the period 2015 through 2019. Data of all patients attending the clinic were retrospectively examined. Files of 103 cases with IH were available for review. The diagnosis of IH was usually straight forward owing to the typical history and characteristic findings at clinical examination. A significant female predominance was noticed. Generally, IH were more common in the head and neck region (70%). Active intervention was necessary in specific situations (eye occlusion, airway involvement, large lesions with skin ulcerations). Whenever intervention proved to be necessary, propranolol was chosen as the first line of treatment with a favourable response detected in about 90% of cases. Surgery was still a valid option (6%) for lesions amenable to resection; however, we must put in consideration that most lesions will spontaneously regress.

Conclusion

Infantile haemangiomas are common benign vascular tumours of infancy with relatively few complications. Cosmesis is a major concern especially for lesions affecting the face. Propranolol can induce tumour regression in most cases, and generally, a favourable outcome can be anticipated.

Recent Progress in Lymphangioma

Lymphangioma is a common type of congenital vascular disease in children with a broad spectrum of clinical manifestations. The current classification of lymphangioma by International Society for the Study of Vascular Anomalies is largely based on the clinical manifestations and complications and is not sufficient for selection of therapeutic strategies and prognosis prediction. The clinical management and outcome of lymphangioma largely depend on the clinical classification and the location of the disease, ranging from spontaneous regression with no treatment to severe sequelae even with comprehensive treatment. Recently, rapid progression has been made toward elucidating the molecular pathology of lymphangioma and the development of treatments. Several signaling pathways have been revealed to be involved in the progression and development of lymphangioma, and specific inhibitors targeting these pathways have been investigated for clinical applications and clinical trials. Some drugs already currently in clinical use for other diseases were found to be effective for lymphangioma, although the mechanisms underlying the anti-tumor effects remain unclear. Molecular classification based on molecular pathology and investigation of the molecular mechanisms of current clinical drugs is the next step toward developing more effective individualized treatment of children with lymphangioma with reduced side effects.

Sirolimus: A Rescue Drug to Control Complications of Extensive Venous Malformation

Venous malformations represent a major sector of vascular anomalies. Most cases are asymptomatic or subclinical; however, large extensive lesions can cause severe disability and sometimes mortality. In this report, we present a successful case of sirolimus treatment in managing an extensive venous malformation in the pelvis of a 21-month-old boy who presented with life-threatening complications. With a history dating since the day 2 of life, the patient suffered from chronic bleeding due to scrotal skin ulcerations, in addition to recurrent attacks of severe bleeding per rectum necessitating hospital admission and blood transfusion (three attacks since the age of 7 months). Pelvic magnetic resonance image showed the typical findings of extensive venous malformation involving the pelvis, perineum, scrotum, and extending to the gluteal region. The lesion was seen totally encasing the anorectum with marked thickening of their walls almost occluding their lumen.

Oral sirolimus (2 mg/m ² ) was started with a target blood trough level of 5 to 10 ng/mL. Over a follow-up period of 5 months, there was obvious clinical improvement that included healing of skin lesions (scrotal ulcer) with complete re-epithelialization, absence of bleeding per rectum with improvement of constipation, and rise of hemoglobin level from 7.5 to 11.5 g/dL.

Long-term health-related quality of life in children with lymphatic malformations treated with sclerotherapy generally matched age-appropriate standardised population norms

AIM

We assessed the long-term health-related quality of life (HRQoL) of children who received sclerotherapy for lymphatic malformations. This treatment involved injecting drugs into the blood vessels to make them shrink.

METHODS

Our cross-sectional study retrospectively reviewed patients who received OK-432 sclerotherapy injections at Karolinska University Hospital, Stockholm, Sweden, from 1998 to 2013. We studied 49 patients (63% female) aged 8-18 at least five years after their first injection. HRQoL was assessed with the KIDSCREEN-52 questionnaire and a study-specific questionnaire addressed disease consequences and patient satisfaction. We determined associations between HRQoL and disease and treatment and the patient's sex.

RESULTS

Overall HRQoL paralleled age-appropriate norms in the general population, but some subgroups had lower levels. Regression-based estimates showed that larger numbers of injections were negatively associated with HRQoL in the dimensions autonomy, parent relations and home life, financial resources and school environment (p = 0.01-0.03). Malformations in the head and neck area were negative predictors across dimensions and were strongest for psychological well-being (p = 0.009), parent relations and home life (p = 0.017) and school environment (p = 0.006).

CONCLUSION

Despite generally positive outcomes, multiple injections and malformations in the head and neck were associated with impaired HRQoL.

Effective Use of Sirolimus and Zoledronic Acid for Multiosteotic Pseudomyogenic Hemangioendothelioma of the Bone in a Child: Case Report and Review of Literature

Pseudomyogenic hemangioendothelioma (PMH) is a rare neoplasm with vascular and sarcomatous elements, unpredictable course, and uncommon metastatic or fatal potential. Although systemic chemotherapy has been reported with variable success, generally accepted treatment is aggressive surgery with wide margins. Evidence-based treatment options are lacking, and lack of clear prognostic features poses a risk of undertreatment or overtreatment with associated morbidity and mortality. We report the use of initial systemic therapy with oral sirolimus (SIR) and IV zoledronic acid (ZA) to induce a sustained clinical response and avoidance of amputation in a 6-year-old boy. At 37 months after diagnosis, our patient remains in sustained clinical remission as documented by x-ray, MRI, and PET-CT with return of normal mobility/activity and resolution of swelling and pain. Literature review identified 20 cases of pediatric and young adult patients with PMH, of which 7 received some form of systemic therapy. To the best of our knowledge, our patient represents the youngest reported case of PMH and the first successful and limb-sparing utilization of systemic chemotherapy as primary treatment for PMH.

Generalized Lymphatic Anomaly and Gorham-Stout Disease: Overview and Recent Insights

Significance: Generalized lymphatic anomaly and Gorham–Stout disease are extremely rare diseases with severe symptoms and poor prognosis. The etiology and clinical presentation of the patients remain poorly defined, but recent research has attempted to determine the pathogenesis of these diseases.

Recent Advances: In recent years, the characteristics of complex lymphatic anomalies have been revealed. Kaposiform lymphangiomatosis is recognized as a new entity that has an aggressive course and poor prognosis. Genetic analysis revealed somatic mutations in genes associated with the phosphoinositide 3-kinase (PI3K) pathway in lymphatic malformation lesions. Somatic NRAS mutation in lymphatic endothelium from a generalized lymphatic anomaly patient was also detected as a potential cause of disease. Furthermore, studies demonstrated the efficacy of the mammalian target of rapamycin (mTOR) inhibitor sirolimus for these lymphatic diseases.

Critical Issues: These diseases have overlapping symptoms, imaging features, and complications, leading to difficulty in their differential diagnosis. In addition, there are no standard therapies. Therefore, we need to determine the differences among these diseases to not only diagnose but also treat them appropriately.

Future Directions: Further investigations should reveal differences in the clinical features and findings of radiological, pathological, and genetic examinations to manage each disease appropriately. Somatic mutation in genes encoding RAS/PI3K/mTOR signaling pathway components could be associated with the pathogenesis of these diseases and may be novel targets for drug therapies.