Vascular anomalies: special considerations in children

Neonatal upper limb arteriovenous malformation: a therapeutic challenge

Arteriovenous malformations (AVMs) are rare congenital vascular malformations with associated morbidities. We describe a neonatal case of upper limb high-flow AVM presenting with upper limb soft tissue mass and postnatal high-output heart failure. Doppler study suggested high-flow AVM, and later magnetic resonance angiography of the right upper limb confirmed the diagnosis. The baby was managed with respiratory support, compression bandage and limb elevation, oral sirolimus and percutaneous embolisation. After percutaneous embolisation using glue, there was a reduction in the size of swelling with wound healing. Post embolisation, the baby remained haemodynamically stable on room air and gained weight on breastfeeds. Treatment of upper limb AVMs is best achieved with a multidisciplinary team to obliterate the arteriovenous shunt to prevent high-output cardiac failure and improve the quality of life.

Injectable chitosan hydrogel effectively controls lesion growth in a venous malformation murine model

PURPOSE

The purpose of this study was to evaluate the safety and efficacy of intralesional injection of chitosan hydrogel (CH) combined with sodium tetradecyl sulfate (STS) to sclerose and embolize venous malformations (VMs) by comparison with 3% STS foam and placebo in a mouse model.

MATERIALS AND METHODS

Subcutaneous VMs were created by injecting HUVEC_TIE2-L914F cells, mixed with matrigel, into the back of athymic mice (Day [D] 0). After VM-like lesions were established at D10, 70 lesions were randomly assigned to one of six treatment groups (untreated, saline, 3% STS-foam, CH, 1% STS-CH, 3% STS-CH). For 3% STS-foam, the standard Tessari technique was performed. VMs were regularly evaluated every 2-3 days to measure lesion size until the time of collection at D30 (primary endpoint). At D30, VM lesions including the matrigel plugs were culled and evaluated by histological analysis to assess vessel size, chitosan distribution and endothelial expression. One-way analysis of variance (ANOVA) test was performed to compare quantitative variables with normal distribution, otherwise Kruskal-Wallis test followed by pairwise comparisons by a Wilcoxon rank sum test was performed.

RESULTS

All VMs were successfully punctured and injected. Six VMs injected with 3% STS-CH showed early skin ulceration with an extrusion of the matrigel plug and were excluded from final analysis. In the remaining 64 VMs, skin ulceration occurred on 26 plugs, resulting in the loss of three 3% STS-foam and one 1% STS-CH plugs. Both chitosan formulations effectively controlled growth of VMs by the end of follow-up compared to untreated or 3% STS-foam groups (P < 0.05). Vessel sizes were smaller with both CH formulations compared to untreated and saline groups (P < 0.05). Additionally, there were smaller vascular channels within the 1% STS-CH group compared to the 3% STS-foam group (P < 0.05).

CONCLUSION

Chitosan's ability to control the growth of VMs suggests a promising therapeutic effect that outperforms the gold standard (STS-foam) on several variables.

Analyzing the safety and efficacy of pipeline embolization device in pediatric aneurysms: insight from a mul-ticenter cohort and pooled analysis

BACKGROUND

Pediatric patients with intracranial aneurysms face high risks of spontaneous subarachnoid hemorrhages. Despite its approval for adults aged 22 and above, the Pipeline Embolization Device (PED, Covidien/Medtronic, Irvine, California, USA) is being considered for younger patients due to its efficacy. This study aims to assess the safety and effectiveness of using PEDs in pediatric aneurysm treatment.

METHODS

A retrospective study across 14 institutions identified 25 patients (age ≤ 18) treated with PED from November 2014 to October 2019. A literature review included all published pediatric aneurysm cases treated with PED from 2007 to 2023. Analyzed data included patient demographics, aneurysm characteristics, treatment, clinical outcomes, and complications.

RESULTS

We analyzed 81 pediatric patients, including 25 from the multi-center registry and 56 from 38 relevant literature. In the entire cohort of 81 patients, mean age of the patients was 11.9 ± 4.0 years (ranged from 9 months to 18 years), with 58.0% males. Ruptured aneurysms were observed in 7 patients (8.6%), whereas 43 patients (53.1%) harbored large/giant aneurysms. The aneurysm occlusion rate was 87.7% during the median 7 months follow-up. Complications occurred in 12.3% of patients, resulting in morbidity in 5 cases (6.1%) and mortality in 4 cases (4.9%). Patient age was not associated with the occurrence of aneurysm residual, complications, and mortality following PED treatment.

CONCLUSIONS

PED can be effective for pediatric aneurysms, but morbidity and mortality can be substantial compared to the adults. Surgical timing should depend on clinical judgment and patient factors, without age-related delays.

Pediatric Vascular Anomalies: A Clinical and Radiological Perspective

According to the International Society for the Study of Vascular Anomalies (ISSVA) classification, vascular anomalies include a diverse range of pathologies, classified as either vascular tumors or vascular malformations. This classification, last revised in 2018, aims to explain the biological basis of vascular lesions and help clinicians to manage the anomalies. In vascular tumors, there are proliferative changes of endothelial cells, while vascular malformations primarily consist of structural vascular abnormalities. Infantile hemangioma is the most common soft-tissue vascular tumor. Vascular malformations are an extensive group of malformations of the arterial, venous, and lymphatic systems, either in isolation or in combination. Radiological evaluation plays a key part in the management of pediatric patients with these entities. The understanding of sonography and magnetic resonance imaging findings entails its correlation with clinical findings at the time of scanning.

Comparison of wireless handheld ultrasound and high-end ultrasound in pediatric patients with venous malformations - First results

AIM

To evaluate the usefulness of handheld ultrasound in comparison with high-end ultrasound for lesion evaluation before and after sclerotherapy in pediatric patients with venous malformations (VMs).

MATERIAL AND METHODS

10 pediatric patients prior to and after sclerotherapy were scanned by an experienced examiner using handheld ultrasound (Vscan AirTM) and high-end ultrasound (LOGIQ E9/E10) as reference. Patients with associated venous thromboses and intralesional aneurysms had been excluded. Results were interpreted independently by two readers in consensus.

RESULTS

10 patients (4-17 years; 10.0±4.32 years; female n = 6, male n = 4) with 10 VMs (4 of the head and neck region, 4 of the upper and 2 of the lower extremities) were examined. 7 phleboliths were detected. The average rating score achieved by the high-end device never was less than 4, by Vscan AirTM never less than 3. An exception was the assessment of AV fistulas. In comparison with the evaluation of variables examined, we found a significant difference between the high-end scanner and the handheld device regarding the achieved image quality.

CONCLUSION

Vscan AirTM ultrasound device allows new possibilities for procedure planning and post-procedural control of pediatric patients with VMs.

Approach to clinically significant vascular anomalies in children

Vascular anomalies consist of tumours or malformations made up of abnormal growth or collections of blood vessels that can result in functional or cosmetic problems. While many vascular anomalies are present at birth, some do not appear until later in life, making diagnosis more challenging. Although many vascular anomalies are benign, some are associated with serious complications and may involve multiple organ systems. This article highlights the important features of clinically significant vascular anomalies to help physicians promptly identify and refer these cases to a specialised multidisciplinary team for evaluation and management. The discussion includes the various presenting complaints of vascular anomalies in children, namely, rapidly growing birthmarks, painful lesions, seizures/neurological manifestations, bleeding diathesis, cardiac/airway abnormalities and part of an overgrowth syndrome.

Clinical effectiveness and safety of sirolimus in pediatric patients with complex vascular anomalies: necessitating personalized and comprehensive approaches

Background

Managing complex vascular anomalies in pediatric care requires comprehensive approaches. Sirolimus, an mTOR inhibitor with immunosuppressive and anti-angiogenic properties, offers promise. We evaluated sirolimus's effectiveness and safety in pediatric patients with complex vascular anomalies at a tertiary children's hospital.

Methods

Our study included 20 patients, aged 1 month to 19 years, with diverse vascular anomalies resistant to conventional therapies or located in high-risk areas precluding surgery. The evaluation of response encompassed measuring the reduction in the size of the targeted vascular or lymphatic lesions as observed on radiologic imaging, along with considering improvements reported by the patients.

Results

Patients used sirolimus for a median of 2.1 years, ranging from 0.6-4.3 years. Results indicated that 60% of patients achieved complete or partial response (CR/PR), whereas 40% had stable disease (SD). Notably, no disease progression occurred. Lesion size assessment was complex, yet patients' self-reported improvements were considered. Three patients reinitiated sirolimus after discontinuation due to worsening lesions. Sirolimus treatment demonstrated good tolerability, with minor complications except for one case of Pneumocystis jiroveci pneumonia. Group comparisons based on response highlighted better outcomes in patients with vascular tumors (CR/PR group 58.0% vs. SD group 0.0%, P = 0.015) or localized measurable lesions (83.3% vs. 12.5%, P = 0.005).

Conclusion

Our study underscores sirolimus's potential for treating complex vascular anomalies in pediatric patients. Challenges associated with optimal treatment duration and concurrent interventions necessitate a comprehensive approach and genetic testing to optimize outcomes.

Development of Biocompatible 3D-Printed Artificial Blood Vessels through Multidimensional Approaches

Within the human body, the intricate network of blood vessels plays a pivotal role in transporting nutrients and oxygen and maintaining homeostasis. Bioprinting is an innovative technology with the potential to revolutionize this field by constructing complex multicellular structures. This technique offers the advantage of depositing individual cells, growth factors, and biochemical signals, thereby facilitating the growth of functional blood vessels. Despite the challenges in fabricating vascularized constructs, bioprinting has emerged as an advance in organ engineering. The continuous evolution of bioprinting technology and biomaterial knowledge provides an avenue to overcome the hurdles associated with vascularized tissue fabrication. This article provides an overview of the biofabrication process used to create vascular and vascularized constructs. It delves into the various techniques used in vascular engineering, including extrusion-, droplet-, and laser-based bioprinting methods. Integrating these techniques offers the prospect of crafting artificial blood vessels with remarkable precision and functionality. Therefore, the potential impact of bioprinting in vascular engineering is significant. With technological advances, it holds promise in revolutionizing organ transplantation, tissue engineering, and regenerative medicine. By mimicking the natural complexity of blood vessels, bioprinting brings us one step closer to engineering organs with functional vasculature, ushering in a new era of medical advancement.

Propranolol for Vascular Anomalies: Efficacy and Complications in Pediatric Patients

Context

Congenital vascular anomalies are classically subdivided into vascular tumors and vascular malformations. The role of propranolol in the regression of infantile hemangioma (IH), a vascular tumor, is well establishe.

Aims

This study aimed to analyze the therapeutic efficacy and complications associated with oral propranolol and adjuvant therapy in the treatment of vascular anomalies.

Settings and Design

A prospective interventional study was undertaken over 10 years duration extending from 2012 to 2022 at a tertiary care teaching institute.

Materials and Methods

All children with cutaneous hemangiomas and lymphatic and venous malformations under 12 years of age, except those with contraindications for administration of propranolol, were included in the study.

Results

Out of 382 patients, there were 159 males and 223 females (male: female = 1:1.4). The majority (53.66%) were between ≥3 months and 1 year. There were 481 lesions in 382 patients. There were 348 patients with IH, and 11 were congenital hemangiomas (CHs). There were 23 patients with vascular malformations; lymphatic malformation (n = 19) and venous malformation (n = 4) were present. The size of the lesions ranged from 5 mm to 20 cm; 50.73% were 2-5 cm in size. Ulceration (>5 mm) was the most common complication present in 20/382 (5.24%) patients. Complications related to oral propranolol were seen in 23 (6.02%) patients. Drugs were given for a mean period of 10 months (range from 5 months to 2 years). At the end of the study, 282 (81.03%) out of 348 patients with IH showed an excellent response; 4 (36.36%) patients in the case of CH (n = 11) and 5 (21.74%) patients with vascular malformation (n = 23) showed excellent response.

Conclusion

The study validates the use of propranolol hydrochloride as the first-line agent for the treatment of IHs and congenital hemangiomas. It may have an additive role in lymphatic malformations, and venous malformations, as a part of a multimodality treatment approach for vascular malformations.

Percutaneous sclerotherapy of microcystic lymphatic malformations: the use of an innovative gravity-dependent technique

BACKGROUND

In the last few decades there has been development of innovative therapies for the treatment of craniofacial lymphatic malformations. Percutaneous sclerotherapy has demonstrated efficacy in the management of macrocystic lymphatic lesions, but it is less suitable for microcystic lesions given their size. The gravity-dependent technique is a novel augmentation of standard percutaneous sclerotherapy: the technique enables a sclerosing agent to permeate the small microchannels seen in microcystic lesions that would otherwise be difficult to treat.

METHODS

Between 2005 and 2021, 124 patients with microcystic or mixed lymphatic malformations were treated using a novel gravity-dependent sclerotherapy technique. Bleomycin at a maximum dose of 15 IU per session was used as the main sclerosing agent. Fluoroscopy and ultrasound were used to ensure proper positioning of the catheter prior to injecting the sclerosing agent. The response to treatment was assessed clinically and with cross-sectional imaging.

RESULTS

Nearly all cases showed significant improvement after the gravity-dependent technique. There have been no permanent complications from sclerotherapy treatment. There was a mild transient adverse effect from bleomycin in one case of erythema and tenderness that lasted several weeks then ameliorated.

CONCLUSIONS

The gravity-dependent sclerotherapy technique is a suitable treatment option for microcystic lymphatic malformations.

Establishment of an interdisciplinary vascular anomalies program in Tanzania, East Africa

Purpose

The aim of this project is the sustainable implementation of a vascular anomalies (VA) program in Tanzania.

Materials and methods

In 2021 the first interdisciplinary VA program was initiated at Muhimbili National Hospital (MNH), Dar Es Salaam, Tanzania in a stepwise approach. During the planning phase the clinical need for minimally-invasive therapies of VAs and the preexisting structures were assessed by the local Interventional Radiology (IR) team at MNH. During the initiation phase, an IR team from two German VA centers joined the interdisciplinary team at MNH for clinical workup, image-guided procedures and follow-up. VA patients were recruited from existing patient records or seen at clinics as de novo presentations following nationwide advertisement. In the post-processing phase joined online conferences for follow-up and support in management of new patients were established. Further follow-up was supported by attending providers from other established VA centers, traveling to bolster the primary operators of MNH.

Results

The first interdisciplinary VA program was successfully launched in Tanzania. Minimally-invasive treatments were successfully trained, by performing ultrasound-guided sclerotherapy with polidocanol and bleomycin in twelve patients with slow-flow malformations, one endovascular embolization of a high-flow malformation, and medical treatment of an aggressive infantile hemangioma. Regular online follow-up presentations have been initiated. Follow-up evaluation and required treatment was sustained when appropriate.

Conclusion

The presented "hands-on" training set the ground for the first interdisciplinary VA program in Tanzania. This framework is expected to establish comprehensive and sustainable care of patients with VAs in East Africa and can serve as a blueprint for other sites.

Clinical Outcome and Quality of Life of Multimodal Treatment of Extracranial Arteriovenous Malformations: The APOLLON Study Protocol

PURPOSE

Arteriovenous malformations (AVMs) as rare diseases are diagnostically and therapeutically challenging. Due to the limited evidence regarding treatment outcome, prospective data are needed on how different treatment regimens affect outcome. The aims of this prospective trial are to determine effectiveness, safety, and clinical outcome of multimodal treatment in patients with extracranial AVMs.

MATERIALS AND METHODS

After clinical and magnetic resonance imaging (MRI)-based diagnosis and informed consent, 146 patients (> 4 years and < 70 years) undergoing multimodal therapy in tertiary care vascular anomalies centers will be included in this prospective observational trial. Treatment options include conservative management, medical therapy, minimally invasive image-guided procedures (embolization, sclerotherapy) and surgery as well as combinations of the latter. The primary outcome is the patient-reported QoL 6 months after completion of treatment using the short form-36 health survey version 2 (SF-36v2) and the corresponding short form-10 health survey (SF-10) for children. In addition, clinical presentation (physician-reported signs), MRI imaging (radiological assessment of devascularization), recurrence rate, and therapeutic safety will be analyzed. Further follow-up will be performed after 12, 24, and 36 months. Moreover, liquid biopsies are being obtained from peripheral blood at multiple time points to investigate potential biomarkers for therapy response and disease progression.

DISCUSSION

The APOLLON trial is a prospective, multicenter, observational open-label trial with unequal study groups to generate prospective evidence for multimodal treatment of AVMs. A multicenter design with the potential to assess larger populations will provide an increased understanding of multimodal therapy outcome in this orphan disease.

TRIAL REGISTRATION

German Clinical Trials Register (identification number: DRKS00021019) https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021019 .

Large scalp venous malformation in a pediatric patient managed with sclerotherapy and surgery: a case report and review of literature

BACKGROUND

Venous malformations (VMs) are slow-flow vascular anomalies present at birth that enlarge during adolescence, subsequently causing thrombosis, hemorrhage, and pain.

CASE PRESENTATION

We describe a case of an adolescent male presenting with a large scalp venous malformation. Given the size and location of the lesion, a hybrid approach employing both sclerotherapy and surgical resection was utilized. The VM was successfully removed without complication.

CONCLUSION

A hybrid approach is a safe and effective treatment consideration for immediate management of large venous malformation in higher-risk locations.

Sociodemographic characteristics of pediatric patients with vascular malformations: Results of a single site study

Vascular malformations, the abnormal development of blood vessels, are a rare set of congenital anomalies. The sociodemographic factors associated with vascular malformations in pediatric patients are poorly understood. This study examined sociodemographic factors of 352 patients presenting to a single vascular anomaly center from July 2019 to September 2022. Characteristics such as race, ethnicity, sex, age at presentation, degree of urbanization, and insurance status were recorded. This data was analyzed by comparing the different types of vascular malformations, including arteriovenous malformation, capillary malformation, venous malformation (VM), lymphatic malformation (LM), lymphedema, and overgrowth syndrome. Patients were primarily white, not Hispanic or Latino, female, had private health insurance, and were from the most urban setting. No differences in sociodemographic factors were found among the different vascular malformations except patients with VM presented at a later age than patients with LM or overgrowth syndrome. This study provides novel insight into the sociodemographic factors of pediatric patients presenting with vascular malformations and indicates a need for their improved recognition for the timely initiation of treatment.

Embolization in Pediatric Patients: A Comprehensive Review of Indications, Procedures, and Clinical Outcomes

Embolization in pediatric patients encompasses a large spectrum of indications, ranging from the elective treatment of congenital diseases of the cardiovascular system to the urgent management of acute hemorrhagic conditions. In particular, the endovascular treatment of central and peripheral vascular malformations and hypervascular tumors represents a wide chapter for both congenital and acquired situations. Thanks to the progressive availability of low-profile endovascular devices and new embolic materials, the mini-invasive approach has gradually overtaken surgery. In this review, the main embolization procedures will be illustrated and discussed, with a focus on clinical indications and expected outcomes. The most recent mini-invasive techniques will be described, with hints on the cutting-edge devices and embolic materials.

Interventional Treatment Options in Children with Extracranial Vascular Malformations

Extracranial vascular malformations vary greatly and belong to the complex field of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic system. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) represents an important guidance for selecting appropriate therapy. Although many of the principles of endovascular treatment, including image-guided sclerotherapy and embolization, are similar in adult and pediatric practice, there are some distinct differences regarding the treatment of vascular malformations of children. Thus, it is crucial to involve longer-term plan about managing these chronic diseases and their impact on a growing child. This review provides a detailed overview over the clinical presentation of venous, lymphatic, and arteriovenous malformations in children and emphasizes the specifics of their interventional treatment options, including distinct pediatric dose limitations and procedure-related side effects.

Balloon occlusion as an adjunctive technique during sclerotherapy of Puig's classified advanced venous malformations

OBJECTIVE

Puig types 2 through 4 venous malformations (VMs) are challenging to treat with sclerotherapy given their robust systemic outflow. Endovenous balloon occlusion offers a means of temporarily occluding systemic venous outflow to allow for more complete sclerotherapy. This study reviews our experience of implementing this technique in patients with Puig advanced (types 2 through 4) VMs.

METHODS

An IRB approved review of treated venous malformations from 2013-2016 revealed 10 patients fitting inclusion criteria. Patient demographics, pre-procedural imaging, intra-procedural technical parameters, and post-procedural follow-up outcomes were recorded. All patients underwent temporary balloon occlusion of a systemic or major draining vein during sclerotherapy. Embolic agents included n-butyl cyanoacrylate glue, sodium tetradecyl sulfate foam, and coils. Standard 5 French angioplasty balloons ranged from 4 to 8 mm diameter and 2 to 8 cm length depending on vessel requiring occlusion. All patients underwent minimum 3-year follow-up questionnaire administration re-assessing resolution of lesion symptomology and post-procedural quality of life (QoL) measures.

RESULTS

Of the 10 VMs treated, 2 were Type 2, 6 were Type 3, and 2 were Type 4. More than one sclerotherapy session was required in 7/10 patients (mean: 2, range: 1-4). Most common sites of VM systemic drainage included subclavian, popliteal, internal/external jugular, and basilic veins. All patients had no indication for further sclerotherapy following adjunctive balloon occlusion. No non-target embolization or immediate post-procedural complications occurred. Follow-up questionnaires (mean interval: 3 years 6 months, range: 3 years-3 years 11 months) confirmed the persistence of embolization effects, improved QoL, and no additional sclerotherapy sessions for all patients in the cohort.

CONCLUSIONS

Endovenous balloon occlusion as an adjunct to sclerotherapy can be considered when treating patients with types 2-4 venous malformations. This technique lowers the risk of non-target systemic venous embolization, allowing for operator-driven deeper intralesional sclerosant penetration and subsequently maintained treatment efficacy.