Preliminary results of the European multicentric phase III trial regarding sirolimus in slow-flow vascular malformations

Hip Dysplasia in a Context of Blue Rubber Bleb Nevus Syndrome, 5-years Follow-up after Hip Arthroplasty

Introduction

Blue rubber bleb nevus syndrome (BRBNS) is a rare congenital vascular disorder that affects the venous system. Lesions are multiple and involved not only the skin and subcutaneous tissue but also muscles, joints and organs such as the gastrointestinal tract. At present, little is known regarding its potential orthopedic complications.

Case Report

We present a unique case of a patient with BRBNS displaying both intra-articular and extra-articular severe venous malformation (VM) of the hip. This extensive VM caused severe deformities in bone growth, mainly affecting the proximal femur, and impacted the muscular development of the gluteus medius and gluteus maximus. Its intra-articular extension, along with repeated secondary hemarthrosis, led to cartilaginous destruction. Consequently, the patient presented with significant coxa valga and developed acetabular dysplasia and subluxation of femoral head, during growth. In order to restore hip function and alleviate pain, the patient underwent a total hip arthroplasty (THA) at the age of 18.

Discussion

The dysplastic changes in the hip joint observed in this case are attributed to the deleterious effects of VMs and coxa valga on joint anatomy and biomechanics. VMs induce recurrent hemarthrosis, leading to cartilage destruction and hip instability. Additionally, coxa valga alters hip biomechanics, exacerbating joint instability and accelerating wear. Surgical intervention with THA aimed to restore joint stability and function, although challenges arose due to anatomical complexities and limited prosthetic options.

Conclusion

This is the first reported case of hip dysplasia associated with BRBNS. This case shows the involvement of vascular malformation in the development of hip dysplasia leading to total hip arthroplasty. The surgical planning and technique must take the specificity of this pathology into account to get the best result possible for the patient. This case illustrates the importance of a multidisciplinary approach to treat patients with this specific syndrome and adds valuable information to the limited literature on orthopedic complications in BRBNS.

Congenital Vascular and Lymphatic Diseases

Over the past several centuries, the integration of contemporary medical techniques and innovative technologies, like genetic sequencing, have played a pivotal role in enhancing our comprehension of congenital vascular and lymphatic disorders. Nonetheless, the uncommon and complex characteristics of these disorders, especially considering their formation during the intrauterine stage, present significant obstacles in diagnosis and treatment. Here, we review the intricacies of these congenital abnormalities, offering an in-depth examination of key diagnostic approaches, genetic factors, and therapeutic methods.

Complex lymphatic anomalies: Molecular landscape and medical management

The lymphatic system is one of the most essential and complex systems in the human body. Disorders that affect the development or function of the lymphatic system can lead to multi-system complications and life-long morbidity. The past two decades have seen remarkable progress in our knowledge of the basic biology and function of the lymphatic system, the molecular regulators of lymphatic development, and description of disorders associated with disrupted lymphangiogensis. In this chapter we will touch on the clinical features of complex lymphatic anomalies, new molecular knowledge of the drivers of these disorders, and novel developmental therapeutics for lymphatic disease.

Targeted treatment in complex lymphatic anomaly: a case of synergistic efficacy of trametinib and sirolimus

Repurposing anticancer drugs to vascular malformations has significantly improved patient outcomes. Complex Lymphatic Anomalies (CLA) are part of the spectrum of lymphatic malformations (LMs) that share similar oncogenic mutations to cancer. We report the case of a young patient with highly symptomatic CLA who was initially treated with sirolimus, due to the frequent involvement of the PI3K-AKT-mTOR pathway in CLA pathogenesis. Despite an initial reduction in symptoms, sirolimus progressively lost its effectiveness. After an unsuccessful attempt with trametinib alone, sirolimus was added to trametinib and resulted in a significant, rapid and sustained improvement in symptoms. This suggests that, contrary to current dogmas, combination therapy using sub-therapeutic doses targeting both the PI3K and RAS pathways retains efficacy without generating the toxicity known for combination therapies, and is beneficial in the management of CLAs and potentially other vascular anomalies.

Congenital Vascular Malformations in Children: From Historical Perspective to a Multidisciplinary Approach in the Modern Era-A Comprehensive Review

Congenital vascular malformations (CVMs) are the result of an aberrant development during embryogenesis. Although these lesions are present at birth, they are not always visible yet. Once symptomatic, patients suffer from pain, bleeding, ulcers, infections or lymphatic leakage, depending on the subtype of vessels involved. Treatment includes conservative management, surgery, sclerotherapy, embolization and pharmacological therapy. The clinical presentation varies widely and treatment can be challenging due to the rarity of the disease and potential difficulties of treatment. This review gives an overview of the historical developments in diagnosis and classification and exposes the key elements of innovations in the past decades on the identification of genetic mutations and personalized treatment. These advances in the field and a multidisciplinary approach are highly valuable in the optimization of clinical care aimed at both curing or stabilizing the CVM and pursuing physical and psychosocial wellbeing.

Infantile hemangioma: the common and enigmatic vascular tumor

Infantile hemangioma (IH) is a benign vascular tumor that occurs in 5% of newborns. The tumor follows a life cycle of rapid proliferation in infancy, followed by slow involution in childhood. This unique life cycle has attracted the interest of basic and clinical scientists alike as a paradigm for vasculogenesis, angiogenesis, and vascular regression. Unanswered questions persist about the genetic and molecular drivers of the proliferating and involuting phases. The beta blocker propranolol usually accelerates regression of problematic IHs, yet its mechanism of action on vascular proliferation and differentiation is unclear. Some IHs fail to respond to beta blockers and regrow after discontinuation. Side effects occur and long-term sequelae of propranolol treatment are unknown. This poses clinical challenges and raises novel questions about the mechanisms of vascular overgrowth in IH.

Lymphatic malformations: mechanistic insights and evolving therapeutic frontiers

The lymphatic vascular system is gaining recognition for its multifaceted role and broad pathological significance. Once perceived as a mere conduit for interstitial fluid and immune cell transport, recent research has unveiled its active involvement in critical physiological processes and common diseases, including inflammation, autoimmune diseases, and atherosclerosis. Consequently, abnormal development or functionality of lymphatic vessels can result in serious health complications. Here, we discuss lymphatic malformations (LMs), which are localized lesions that manifest as fluid-filled cysts or extensive infiltrative lymphatic vessel overgrowth, often associated with debilitating, even life-threatening, consequences. Genetic causes of LMs have been uncovered, and several promising drug-based therapies are currently under investigation and will be discussed.