Lymphatic malformations (LM), or lymphangiomas, are common vascular anomalies in children, most often occurring in the head and neck, less commonly in the axilla, abdomen, thorax, groin, and extremities. These benign but locally invasive lesions can cause complications such as respiratory issues, difficulty swallowing, nerve compression, bleeding, and cosmetic disfigurement. Treatment traditionally involves surgical excision, but this approach carries risks such as nerve damage, high recurrence, and poor cosmetic results. In recent years, sclerotherapy, specifically Bleomycin injection, has emerged as a less invasive alternative, offering potential benefits like reduced recurrence and better cosmetic outcomes.

Since its introduction in Vietnam in 2016, Bleomycin has been used to treat LM, but comprehensive studies on its safety, efficacy, and long-term outcomes in pediatric patients are lacking. This study aims to fill this gap by evaluating the effectiveness of intralesional Bleomycin injections in children with LM treated at the National Children's Hospital between 2018 and 2022.

The study will assess the safety, efficacy, and long-term outcomes of Bleomycin, focusing on lesion size reduction, recurrence rates, and cosmetic and health-related quality of life (QoL) improvements. The retrospective study will involve more than 800 pediatric patients and use tools like the Patient Scar Assessment Questionnaire (PSAQ) and Short Form-36 (SF-36) health survey to evaluate cosmetic outcomes and overall well-being.

The research will also compare the effectiveness of Bleomycin alone versus in combination with surgery, examining whether Bleomycin can reduce the need for additional interventions. By offering a comprehensive evaluation of both clinical and patient-reported outcomes, the study aims to establish Bleomycin as a viable, minimally invasive treatment option for pediatric LM, improving both clinical and cosmetic outcomes for these patients.

In addition, this study will provide valuable local data on Bleomycin's use in Vietnam, potentially influencing national treatment guidelines. The results will be disseminated in peer-reviewed journals, contributing to global understanding of Bleomycin's role in managing lymphatic malformations in children.

Lymphatic malformations (LM), often referred to as lymphangiomas, are a form of vascular malformation that arises due to the abnormal development of the lymphatic system. These benign but locally invasive lesions are one of the most common vascular anomalies in children. The highest incidence of lymphangiomas is seen in the head and neck region, where they can cause a range of serious complications such as respiratory obstruction, dysphagia (difficulty swallowing), and nerve compression. Less commonly locations of lymphangiomas include axilla, abdomen, thorax, groin, and extremities which could cause bleeding, compression of adjacent structures, and visible deformity, pain and discomfort. Left untreated, these malformations can lead to significant morbidity and functional impairment, as well as severe cosmetic disfigurement, particularly in pediatric patients.

Historically, surgical excision has been the primary treatment for lymphangiomas. However, this approach carries several risks, including damage to surrounding vital structures such as nerves and blood vessels, high recurrence rates due to incomplete excision, and unsightly scars. Over the last few decades, sclerotherapy (ST) has emerged as a less invasive, more favorable alternative that reduces morbidity while achieving superior cosmetic outcomes. Among various sclerosing agents, Bleomycin has gained popularity due to its mechanism of disrupting cellular functions in the abnormal lymphatic endothelial cells, leading to regression of the lesion.

Since its introduction to Vietnam in 2016, Bleomycin has been increasingly used as an adjunctive therapy for lymphangiomas. Despite its growing clinical application, there is a significant lack of comprehensive studies evaluating the safety, efficacy, and long-term outcomes of Bleomycin sclerotherapy in treating pediatric lymphatic malformations, particularly in the Vietnamese population. To date, no large-scale studies have assessed the clinical impact and quality-of-life outcomes of Bleomycin treatment for LM in children within the Vietnamese context. This study seeks to fill this gap in knowledge by comprehensively evaluating the long-term outcomes of intralesional Bleomycin injections in pediatric patients with lymphatic malformations treated at the National Children's Hospital in Vietnam.

The primary objective of this study is to evaluate the safety, efficacy, and long-term outcomes of intralesional Bleomycin injection for pediatric patients diagnosed with lymphatic malformations. The research will focus on both clinical success (such as reduction in lesion size and recurrence rates) and the cosmetic and health-related quality of life (QoL) improvements observed in the patients post-treatment. The study will also examine whether Bleomycin can effectively reduce the need for additional surgical interventions, thus improving both functional and aesthetic outcomes for these children.

This retrospective study will involve a cohort of more than 800 pediatric patients diagnosed with lymphatic malformations and treated with Bleomycin injections at the National Children's Hospital between 2018 and 2022. These patients will be evaluated for safety and efficacy by reviewing their medical records, monitoring for complications, and assessing the recurrence rates of lymphangiomas after treatment. Additionally, long-term cosmetic outcomes will be evaluated using validated patient-reported measures, such as the Patient Scar Assessment Questionnaire (PSAQ), and health-related quality of life will be assessed using the Short Form-36 (SF-36) health survey.

The study aims to assess the safety and efficacy of Bleomycin injection in pediatric patients diagnosed with lymphatic malformations at the National Children's Hospital between 2018 and 2022. This will be done by focusing on post-treatment complications and recurrence rates. Furthermore, the research intends to evaluate the long-term clinical outcomes, including lesion regression, recurrence, and the need for additional interventions. This will help assess the impact of Bleomycin on lesion size, post-treatment complication rates, and the overall clinical success of the intervention.

Another important goal of the study is to analyze the cosmetic outcomes and health-related quality of life in pediatric patients treated with Bleomycin sclerotherapy. The study will use standardized assessment tools like the PSAQ for scarring and the SF-36 for overall health outcomes. These tools will help quantify the patient-reported perception of treatment effects, including both cosmetic outcomes (scar appearance and symptoms) and overall well-being.

Additionally, the study will investigate the role of Bleomycin as a standalone treatment or in combination with surgical interventions to enhance treatment success while minimizing risks and complications associated with invasive procedures. By comparing these approaches, the research aims to determine if Bleomycin alone is sufficient or if a multimodal approach is more effective in treating lymphangiomas.

The results of this study will provide important insights into the feasibility and effectiveness of Bleomycin as an alternative to traditional surgical excision for the treatment of pediatric lymphangiomas. By examining both objective clinical outcomes and subjective patient-reported outcomes, such as quality of life and scar perception, this research will offer a comprehensive understanding of the benefits and challenges of using Bleomycin for this indication. The findings are expected to influence the clinical management of lymphangiomas in pediatric patients, offering evidence-based recommendations on the use of Bleomycin as a safe, effective, and cosmetically favorable treatment option.

Additionally, the study will contribute to filling the gap in local research on the use of Bleomycin for lymphatic malformations in Vietnam, a country where the clinical application of this agent has been relatively new and unstudied. The results of this research could lead to the establishment of evidence-based guidelines for Bleomycin treatment in the Vietnamese healthcare system, supporting its wider adoption as a standard therapy for lymphangiomas.

The study will be conducted with a strict ethical framework, ensuring that all patients and their families provide informed consent before participation, and that their privacy and confidentiality are strictly maintained. Data will be anonymized and stored securely throughout the research process. The findings will be disseminated through peer-reviewed scientific journals, with a particular focus on journals related to pediatric surgery, dermatology, and vascular anomalies, which could help raise awareness of Bleomycin's potential as a viable therapeutic option in the management of lymphangiomas.

In conclusion, this study will not only provide critical clinical data on the efficacy and safety of Bleomycin for treating pediatric lymphangiomas, but it will also enhance our understanding of the long-term cosmetic outcomes and quality of life improvements associated with this treatment. By offering a minimally invasive, less risky alternative to surgical excision, Bleomycin could revolutionize the management of lymphatic malformations in children, improving their health outcomes and overall well-being while minimizing the physical and psychological impact of the disease.

Inclusion Criteria:

• Age: Pediatric patients under the age of 18 years.
• Diagnosis: Confirmed diagnosis of lymphangioma (lymphatic malformation).
• Location of Lesions: Lymphangiomas located in the head and neck, axilla, abdomen, thorax, groin, or extremities.
• Treatment History: No prior treatment with Bleomycin for lymphangioma.
• Health Status: No serious comorbidities or medical conditions that could interfere with the study or treatment process.
• Informed Consent: Patients (or their legal guardians) provide informed consent to participate in the study.

Exclusion Criteria:

• Age: Patients over the age of 18 years.
• Pregnancy: Pregnant or breastfeeding patients.
• Other Treatments: Patients who have received prior treatments with Bleomycin for lymphangioma.
• Severe Comorbidities: Presence of serious comorbidities (e.g., uncontrolled cardiovascular disease, active infections) that may interfere with the study or treatment process.
• Allergy: Known allergy or hypersensitivity to Bleomycin or any of its components.
• Active Infections: Patients with active local or systemic infections at the time of enrollment.
• Immunosuppression: Immunocompromised patients (due to illness or medications).

The population of pediatric patients for this study will consist of children under the age of 18 who have been diagnosed with lymphangiomas (lymphatic malformations). These patients will have a variety of lesion locations, including the head and neck, axilla (armpit), abdomen, thorax (chest), groin, or extremities. The age range will encompass infants, children, and adolescents. They might or might not have received previous treatment with Bleomycin or other interventions for lymphatic malformations. Additionally, they might or might not serious comorbidities such as uncontrolled systemic diseases or immunosuppressive conditions. The cohort will be selected from the patient population at the National Children's Hospital, and participants will be enrolled based on a confirmed diagnosis of lymphangioma from 2018 to 2022.