Diagnosis and management of children with Blue Rubber Bleb Nevus Syndrome: A multi-center case series

Treatment options for gastrointestinal bleeding blue rubber bleb nevus syndrome: Systematic review

OBJECTIVES

Blue rubber bleb nevus syndrome (BRBNS) is a rare challenging cause of gastrointestinal bleeding. We performed a systematic review of case reports and case series on BRBNS to gather information on the treatment options currently available.

METHODS

All studies reporting a case of BRBNS in humans were evaluated. Papers were ruled out if CARE criteria and explanations on patient's selection, ascertainment, causality, and reporting were not respected or identified. PROSPERO 2021 CRD 42021286982.

RESULTS

Blue rubber bleb nevus syndrome was treated in 106 cases from 76 reports. 57.5% of the population was under 18 years old, and up to 50% of the cases reported a previous treatment. Clinical success was achieved in 98 patients (92.4%). Three main types of interventions were identified: systemic drug therapy, endoscopy, and surgery. After BRBNS recurrence or previous therapy failure, systemic drug therapy emerged as a preferred second-line treatment over endoscopy (P = 0.01), but with a higher rate of reported adverse events when compared with surgery and endoscopy (P < 0.001). Endoscopic treatment was associated with a higher number of required sessions to achieve complete eradication when compared with surgery (P < 0.001). No differences between the three main areas were found in the overall follow-up time (P = 0.19) or in the recurrence rate (P = 0.45).

CONCLUSION

Endoscopy, surgery, and systemic drug therapy are feasible treatment options for BRBNS. Systemic drug therapy was the favorite second-line treatment after endoscopic failure or recurrence of BRBNS, but adverse events were more frequently reported.

Sirolimus for vascular anomalies in the first year of life: a systematic review

Evidence on effectiveness and safety of sirolimus in congenital vascular anomalies in infancy is lacking. We aim to systematically review the efficacy and safety of sirolimus in treating congenital VA in infancy. We searched for and included all studies evaluating sirolimus for VA in the first year of life. The primary outcome was effectiveness. The secondary outcome was safety. We included 84 case series and reports (172 participants). Sirolimus decreased the size of the VA in >50% of participants, most of whom had minor transient side effects, and 27% had no adverse effects at all. When categorized by age (<1 month, 1-5 months and 6-12 months), the effectiveness was similar in all age groups. Available evidence suggests that sirolimus is effective and well tolerated. The effectiveness of sirolimus should be evaluated in a well-designed randomized controlled or observational studies.

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.

Surgical considerations for spinal epidural hematoma evacuation in the setting of blue rubber bleb nevus syndrome in a child

Blue rubber bleb nevus syndrome (BRBNS) is a rare condition that presents with venous malformation blebs throughout the body, most commonly on the skin and gastrointestinal tract. There have only been a limited number of reports of benign BRBNS lesions involving the spine in children, which were detected after chronic symptomatology. We herein present a unique case of a ruptured BRBNS venous malformation into the epidural space of the lumbar spine in a child presenting with acute neurologic deficit and discuss the relevant surgical considerations for operating in the setting of BRBNS.

Sirolimus for management of GI bleeding in blue rubber bleb nevus syndrome: A case series

Blue rubber bleb nevus syndrome (BRBNS) commonly presents with anemia from bleeding gastrointestinal (GI) vascular malformations. Management is highly variable, as no consensus guidelines for medical treatment currently exist. Sirolimus has been used in BRBNS to decrease GI bleeding and seems well tolerated, though questions remain regarding dosing, duration of therapy, and adverse effects. Here, we report our single-center experience of four pediatric patients with BRBNS who were successfully treated with sirolimus and review the existing literature regarding sirolimus for treatment of GI bleeding in BRBNS. Further prospective studies are needed to establish optimal dosage, drug monitoring, and duration.

Cerebrospinal fluid leak in epidural venous malformations and blue rubber bleb nevus syndrome

OBJECTIVE

Clinical manifestations of blue rubber bleb nevus syndrome (BRBNS) and multifocal venous malformation (MVM) vary depending on the location of the lesions. The aim of this study was to assess the risk of developing CSF leaks in patients with epidural venous malformations (VMs).

METHODS

The authors retrospectively investigated the relationship between the development of a CSF leak and the presence of epidural VMs.

RESULTS

Nine patients (5 females) had epidural VMs and presentation that was confirmatory or suggestive of a CSF leak: 4 had BRBNS, 4 had MVMs, and 1 had a solitary VM. Of 66 patients with BRBNS, clinical and imaging features of CSF leak were noted in 3 (4.5%) with epidural VMs at the age of 11-44 years. A fourth patient had suggestive symptoms without imaging confirmation. An epidural blood patch was ineffective in 2 patients, both with more than one source of leakage, requiring surgical repair or decompression. Symptomatic downward displacement of the cerebellar tonsils was noted in 3 patients with MVM and 1 with a solitary VM; 3 required surgical decompression.

CONCLUSIONS

These findings suggest an increased risk of CSF leak in patients with epidural VM, including BRBNS, MVMs, and solitary VMs. Awareness of the association between epidural VM and CSF leakage may facilitate earlier diagnosis and therapeutic intervention.

Somatic TEK variant with intraarticular venous malformation and knee hemarthrosis treated with rapamycin

BACKGROUND

Venous malformations (VMs) are the most common vascular anomalies and have been associated with somatic variants in TEK. Current treatment of VM joint component might be challenging due to the size or location of some lesions or ineffective with recurrence of malformed veins. Targeted molecular therapies after identification of genetic defects might be an alternative.

METHODS

We report a case with intraarticular bleeding due to VM with a TEK pathogenic somatic variant treated with rapamycin.

RESULTS

A 26-year-old female patient was evaluated for right calf pain secondary to venous malformation of the right inferior limb with an intraarticular component in the right knee. Hemarthrosis and degenerative chondropathy of the knee were evidenced at MRA. Molecular diagnosis evidenced a pathogenic somatic TEK variant. Rapamycin was introduced to stop bleeding, with good tolerance and efficacy.

CONCLUSION

The TEK receptor signals through the PI3K/AKT/mTOR pathway and TEK mutations have been linked to AKT activation. As rapamycin acts against angiogenesis and reduces phosphorylated-AKT levels, targeted molecular therapy should be discussed as first-line therapy in patients with proven molecular diagnosis and diffuse VM inaccessible to conventional treatment.

Sirolimus as a promising drug therapy for blue rubber bleb nevus syndrome: Two-case report

Blue rubber bleb nevus syndrome is a very rare systemic vascular malformation frequently affecting the skin and the gastrointestinal tract. The pathogenesis of the disease is still unclear, and the standard treatment does not exist. This study reports two blue rubber bleb nevus syndrome cases, of which the second patient received the TEK gene mutations detection and got a low-dose sirolimus therapy, compared with the first patient who was not treated with sirolimus. The report shows some positive findings of TEK gene mutations and the efficacy of sirolimus treatment. We postulate that the TEK gene mutations play an important role in the pathogenesis. The mutations of different locations of the TEK gene cause a wide range of activating TIE2 mutations, which could stimulate the mammalian target of rapamycin signaling pathways to mediate angiogenesis, resulting in different clinical phenotypes of cutaneomucosal venous malformations. Sirolimus could effectively block the upstream and downstream factors of mammalian target of rapamycin signaling pathways to achieve the antiangiogenic effect. The initial dose of sirolimus can be 0.05–0.1 mg/kg/d for a trough level of 5–15 μg/L in the treatment of blue rubber bleb nevus syndrome. However, a lower-dose sirolimus is also effective while minimizing the side effects.

Application of Argon Plasma Coagulation for Gastrointestinal Angiodysplasia in Children- Experience From a Tertiary Center

BACKGROUND

Argon plasma coagulation (APC) has been applied in adults to treat various diseases, including vascular lesions in the gastrointestinal (GI) tract. However, angiodysplasia (AD) is an uncommon cause of pediatric GI bleeding, while the experience of treating AD with APC was rarely reported.

METHODS

Five children with AD in the GI tract successfully treated with APC were reviewed.

RESULTS

Three of the five patients were girls, and the age at diagnosis ranged from 1.5 months to 10.5 years of age. One patient with gastric AD manifested with tarry stool, and the rest had colonic AD, which caused various degrees of bloody stool. Three patients had evident anemia. All patients received an endoscopic diagnosis, and two had compatible findings in radiographic exams. Each patient underwent one APC treatment session, and none encountered procedure-related complications or re-bleeding.

CONCLUSION

AD can be an etiology of GI bleeding even in neonates. APC is an effective and safe therapy for symptomatic AD in children.

Blue rubber bleb nevus syndrome: a single-center case series in 12 years

BACKGROUND

Blue rubber bleb nevus syndrome is a rare congenital disease characterized by multiple venous malformations in skin and gastrointestinal tract, not all patients have typical cutaneous lesions, refractory anemia may be the only clinical symptom, it is easy to miss diagnosis.

METHODS

A retrospective single center study was conducted on 8 patients with blue rubber bleb nevus syndrome from 2009 to 2021. Data were analyzed including clinical feature, diagnostic workup and results, gene detection, treatment and follow-up.

RESULTS

Five children (62.5%) developed the disease in infancy, which initial symptoms were all cutaneous venous malformations. All children had chronic refractory anemia and gastrointestinal bleeding. Cutaneous lesions were observed in 87.5%, 1 child had multiorgan involvement. Gastrointestinal venous malformations were observed in 100%, lesions were more common in small intestine than in stomach or colon. No somatic mutation in TEK was found in our children. Diagnostic interval was on average 4.7 years. Eighty-seven-point-five percent children received at least one endoscopic or surgical intervention, however, those methods could not eradicate all the lesions and prevent relapse. Two children treated with sirolimus for more than 8 years, only 1 have satisfactory therapeutic effect. Besides, I child has growth retardation and emotional problems during follow-up.

CONCLUSIONS

Blue rubber bleb nevus syndrome needs to be considered when find bluish nodular cutaneous lesions, chronic anemia or gastrointestinal bleeding of unknown origin. Capsule endoscopy is the most sensitive in diagnosing of this disease. Oral sirolimus at a relatively low dosage is effective, further comprehensively studies are required to evaluation of its efficacy, safety and the optimal dosage about the children.

Blue Rubber Bleb Nevus Syndrome because of 12 Years of Iron Deficiency Anemia in a Patient by Double Balloon Enteroscopy; A Case Report and Review of Literature

Blue rubber bleb nevus syndrome (BRBNS) is a rare disorder comprised of venous malformation mostly involving the skin and gastrointestinal (GI) tract but can also involve other visceral organs. The most predominant site of GI tract involvement is the small bowel. In patients with GI lesions, treatment depends on the severity of bleeding, and extent of involvement. Conservative therapy with iron supplementation and blood transfusion is appropriate in cases with mild bleeding but in severe cases endoscopic and surgical interventions would be beneficial. Also, medical therapy with sirolimus significantly reduces bleeding. A 20-year-old woman was referred to our hospital after transfusion of six units of packed cell because of several episodes of lower GI bleeding within the past three months in the form of melena and a single episode of hematochezia. Her last hemoglobin level before admission was 10mg/dl. She underwent various unsuccessful investigations since she was eight years old to find the origin of refractory iron deficiency anemia. In upper endoscopy, five bleeding polypoid lesions were discovered in the jejunum. Lesions were excised by snare polypectomy. Over a six-month follow-up period, no signs of lower GI bleeding were noted and the patient had a normal hemoglobin level.

Venous Malformations in Childhood: Clinical, Histopathological and Genetics Update

Our knowledge in vascular anomalies has grown tremendously in the past decade with the identification of key molecular pathways and genetic mutations that drive the development of vascular tumors and vascular malformations. This has led us to better understand the pathogenesis of vascular lesions, refine their diagnosis and update their classification while also exploring the opportunity for a targeted molecular treatment. This paper aims to provide an overview of venous malformations (VM) in childhood. Specific entities include common VMs, cutaneo-mucosal VM, blue rubber bleb nevus syndrome or Bean syndrome, glomuvenous malformation, cerebral cavernous malformation, familial intraosseous vascular malformation and verrucous venous malformation. The clinicopathological features and the molecular basis of each entity are reviewed.

Sirolimus treatment for neonate with blue rubber bleb nevus syndrome: A case report

BACKGROUND

Blue rubber bleb naevus syndrome (BRBNS) is a rare disease that usually presents with multiple venous malformations in the skin and gastrointestinal tract. Lesions located in the gastrointestinal tract always result in chronic gastrointestinal bleeding and severe anemia. The successful management of BRBNS with sirolimus had been reported in many institutions, due to its impact on signaling pathways of angiogenesis. However, the experience in treatment of neonates with BRBNS was limited.

CASE SUMMARY

A 38-day-old premature female infant born with multiple skin lesions, presented to our center complaining of severe anemia and hematochezia. Laboratory examination demonstrated that hemoglobin was 5.3 g/dL and contrast-enhanced abdominal computed tomography showed multiple low-density space-occupying lesions in the right lobe of the liver. She was diagnosed as having BRBNS based on typical clinical and examination findings. The patient was treated by transfusions twice and hemostatic drugs but symptoms of anemia were difficult to alleviate. A review of BRBNS case reports found that patients had been successfully treated with sirolimus. Then the patient was treated with sirolimus at an average dose of 0.95 mg/m²/d with a target drug level of 10-15 ng/mL. During 28 mo of treatment, the lesion was reduced, hemoglobin returned to normal, and there were no adverse drug reactions.

CONCLUSION

This case highlights the dosing regimen and plasma concentration in neonates, for the current common empiric dose is high.

Subconjunctival Hemorrhage in a Child with the Blue Rubber Bleb Nevus Syndrome on Treatment with Oral Propranolol

Blue rubber bleb nevus syndrome (BRBNS) is a rare syndrome characterized by venous malformations of mostly skin and gastrointestinal tract. Patients present with multiple venous malformations in various organs including liver, spleen, heart, eye, and central nervous system. Few ophthalmological cases have been published in literature and at present, there are no clear guidelines on the treatment of eye hemorrhages associated with the BRBNS. We report a 3-year-old boy with the BRBNS who developed a spontaneous progressive enlarging subconjunctival hemorrhage in the left eye despite being treated with oral propranolol. The subconjunctival hemorrhage was caused by an underlying conjunctival vascular malformation. With topical treatment with timolol maleate 0.5% once a day in the affected eye, the lesion regressed completely after 4 months. This child represents the first case of the BRBNS associated with a subconjunctival progressive bleeding necessitating topical treatment despite oral propranolol effectively controlling the cutaneous lesions. We recommend ophthalmic screening of patients with BRBNS in early childhood. For patients with BRBNS-related subconjunctival vascular lesions with subsequent hemorrhage, treatment with a topical β-blocker may be an efficient and harmless treatment option.

Efficacy and Safety of Sirolimus for Blue Rubber Bleb Nevus Syndrome: A Prospective Study

INTRODUCTION

Blue rubber bleb nevus syndrome (BRBNS) is a rare systemic venous malformation (VM) disease. The characteristic gastrointestinal (GI) bleeding from multiple VM lesions causes severe chronic anemia which renders most patients depend on lifelong blood transfusion and frequent endoscopic treatment with dismayed outcomes. Although recent case reports suggest that oral sirolimus (rapamycin) is effective, a comprehensive evaluation of its efficacy and safety is in need.

METHODS

A prospective study was conducted for both pediatric and adult BRBNS patients with administration of sirolimus at the dose of 1.0 mg/m2 to maintain a trough concentration of 3-10 ng/mL. Laboratory tests including complete blood count, biochemical profile, D-dimer, and whole-body magnetic resonance imaging were performed at baseline and 3, 6, and 12 months after treatment. Clinical indicators such as hemoglobin level, lesion size, and transfusion need were evaluated. Adverse effects were recorded regularly.

RESULTS

A total of 11 patients (4 males and 7 females) with median age of 14 (range, 5-49) years were recruited. The average lesion size was reduced by 7.4% (P < 0.001), 9.3% (P < 0.001), and 13.0% (P < 0.05) at 3, 6, and 12 months of sirolimus treatment, respectively. Hemoglobin increased significantly after 6- and 12-month treatment (P = 0.006 and 0.019, respectively). Only 1 patient received blood transfusion once during the study. Patients' quality of life and coagulation function were improved. Grade 1-2 adverse effects including oral ulcers (81.8%), acne (27.3%), transient elevation of liver enzymes (18.2%), and hair loss (9.1%) were observed.

DISCUSSION

Sirolimus reduces the size of VMs, alleviates GI bleeding, and eliminates transfusion dependence of patients with BRBNS. The drug-related adverse effects are mild and mostly self-limited. These findings support sirolimus as a first-line treatment for GI and cutaneous VMs of BRBNS (see Visual abstract, Supplementary Digital Content, http://links.lww.com/AJG/B819).

Role of Video Capsule in Small Bowel Bleeding

Video capsule endoscopy has an essential role in the diagnosis and management of small bowel bleeding and is the first-line study recommended for this purpose. This article reviews the risk factors for small bowel bleeding, optimal timing for video capsule endoscopy testing, and algorithms recommended for evaluation. Used primarily for the assessment of nonacute gastrointestinal blood loss, video capsule endoscopy has an emerging role for more urgent use in emergency settings and in special populations. Future software incorporation of neural networks to enhance lesion detection will likely result in an augmented role of video capsule endoscopy in small bowel bleeding.

Cutaneous venous malformations as a clue for possible gastrointestinal tract involvement: Diagnosis and treatment of six cases

Venous malformation (VM) is the most common type among vascular malformations classified by the International Society for the Study of Vascular Anomalies. Most VMs are sporadic (94%), caused in 40% of cases by somatic mutation of TEK gene. VMs can be cutaneous, visceral, or combined. Visceral involvement is rare, and gastrointestinal (GI) tract is the most common localization. Visceral VMs, usually asymptomatic, may manifest with bleeding, anemia, and consumptive coagulopathy, which sometimes require an emergency treatment. Our aim is to study the possible GI involvement in patients with only one cutaneous VM. We analyzed a series of six patients who presented with a single cutaneous VM and have subsequently manifested intestinal involvement at our reference center for vascular anomalies since 2010. In our patients, cutaneous VMs were located on lower or upper limbs, and GI involvement manifested from 3 to 10 years after skin diagnosis. Our experience urges to early diagnose a GI involvement also in patients with only one skin VM and to prevent severe complications. A multidisciplinary approach is mandatory for the diagnosis and treatment of these patients.

Endoscopic treatment of blue rubber bleb nevus syndrome in a 4-year-old girl with long-term follow-up: A case report

BACKGROUND

Blue rubber bleb nevus syndrome (BRBNS) is a rare vascular disease, difficult to diagnose and choose a treatment method, especially in young children. There are several limiting factors to the use of enteroscopy for diagnostics and treatment in pediatric patients, in general. The literature on BRBNS cases is limited and presents various therapeutic approaches.

CASE SUMMARY

We present here a case of BRBNS involving a 4-year-old female, whose intestinal venous lesions were successfully treated by endoscopic sclerotherapy and aethoxysklerol foam. Skin lesions, typical for BRBNS, appeared on the 8^th d of the child’s life and their number increased over the next several months. The child also experienced episodes of critical decrease in hemoglobin level (by as much as 52 g/L) for several years, requiring iron supplementation and several blood transfusions. Video capsule endoscopy revealed numerous vascular formations in the small bowel. The combined findings of gastrointestinal venous formations and skin lesions prompted BRBNS diagnosis. Single-balloon enteroscopy was used to perform sclerotherapy, with aethoxysklerol foam. A positive effect was observed within 19 mo of follow-up. We continue to monitor the patient’s hemoglobin level, every 2 wk, and it has remained satisfactory (> 120 g/L).

CONCLUSION

Endoscopic sclerotherapy can be effective in the clinical management of gastrointestinal manifestations of BRBNS in young children.

Long-term sirolimus treatment in blue rubber bleb nevus syndrome: Case report and review of the literature

Blue rubber bleb nevus syndrome is a rare vascular syndrome characterized by continuous eruption of vascular nodules in the skin, mucous membranes, and solid organs due to somatic activating mutations of the angiopoietin receptor TEK gene. It may be complicated by acute life-threatening hemorrhage and localized intravascular coagulation. We report an 11-year-old girl with complicated blue rubber bleb nevus syndrome treated with sirolimus since the age of 2. We review the literature on sirolimus therapy for children with blue rubber bleb nevus syndrome.

Vascular Birthmarks as a Clue for Complex and Syndromic Vascular Anomalies

Vascular birthmarks are common in neonates (prevalence: 20-30%) and mostly incidental findings sometimes with spontaneous regression (salmon patch and nevus simplex). Capillary malformations are found in about 1% and infantile hemangiomas are found in 4% of mature newborns. Vascular malformations are classified according to their most prominent vessel type. The term "capillary malformation" (port wine stain) includes a wide range of vascular lesions with different characteristics; they may be isolated or part of specific syndromic conditions. Part of the infantile hemangiomas and of the vascular malformations may require treatment for functional or cosmetic reasons, and in rare cases, investigations are also necessary as they represent a clue for the diagnosis of complex vascular malformation or tumors associated with extracutaneous abnormalities. Complex vascular malformations are mostly mosaicism due to early somatic mutations. Genetic advances have led to identify the main pathogenic pathways involved in this disease group. Diffuse capillary malformation with overgrowth, Klippel-Trenaunay syndrome, CLAPO syndrome, CLOVES syndrome, and megalencephaly-capillary malformation belong to the PIK3CA-related overgrowth. Capillary malformation-arteriovenous malformation underlies a fast-flow vascular malformation, sometimes manifesting as Parkes-Weber syndrome. Recognition of these different types of capillary vascular stains is sometimes difficult; however, associated findings may orient the clinicians while genetic testing may confirm the diagnosis. Lymphatic malformation frequently manifests as large masses that compress and/or infiltrate the surrounding tissues, representing a neonatal emergency when airways are involved. Infantile hemangiomas may cause functional and/or permanent esthetical damage, depending on their localization (such as periorbital area, lip, nose); large (more than 5 cm) infantile hemangiomas with a segmental distribution can be associated with obstruction or malformations of the underneath organs with complications: PHACE syndrome, LUMBAR/SACRAL syndrome, and beard infantile hemangioma. In our review, we discuss controversies regarding the international classification and emerging concepts in the field of vascular anomalies. Finally, we discuss potential developments of new, non-invasive diagnostic techniques and repurposing of target therapies from oncology. Complex and/or life-threatening vascular tumors and malformations are extremely rare events and they represent a considerable therapeutic challenge. Early recognition of clinical signs suggestive for a specific disease may improve therapeutic outcomes and avoid severe complications.

Keystone Flap Reconstruction after Resection of a Large Paraspinal Venous Malformation in an Infant

The keystone flap is well known to plastic surgeons and is frequently utilized for its ease of implementation, limited donor site morbidity, and favorable aesthetic outcomes. Although keystone flaps have been described in reconstruction of myelomeningocele defects, there have been no reports of their application to infants with large vascular malformations. This case illustrates the utilization of a keystone flap in reconstruction of a large posterior trunk defect that resulted from excision of a massive venous malformation in an 8-week-old infant with blue rubber bleb nevus syndrome. The patient’s consumptive coagulopathy resolved in the early postoperative period, and long-term follow-up demonstrated a favorable aesthetic outcome. This case reiterates the power and versatility of the keystone flap technique through its novel application to an infant with a life-threatening venous malformation on the posterior trunk.

New and Emerging Targeted Therapies for Vascular Malformations

Vascular malformations are inborn errors of vascular morphogenesis and consist of localized networks of abnormal blood and/or lymphatic vessels with weak endothelial cell proliferation. They have historically been managed by surgery and sclerotherapy. Extensive insight into the genetic origin and molecular mechanism of development has been accumulated over the last 20 years. Since the discovery of the first somatic mutations in a vascular anomaly 10 years ago, it is now recognized that they are perhaps all caused by inherited or somatic mutations in genes that hyperactivate two major intracellular signaling pathways: the RAS/MAPK/ERK and/or the phosphatidylinositol 3 kinase (PIK3)/protein kinase B/mammalian target of rapamycin (mTOR) pathway. Several targeted molecular inhibitors of these pathways have been developed, mostly for the treatment of cancers that harbor mutations in the same pathways. The mTOR inhibitor sirolimus is the most studied compound for the treatment of venous, lymphatic, and complex malformations. Disease responses of vascular malformations to sirolimus have now been reported in several studies in terms of clinical changes, quality of life, functional and radiological outcomes, and safety. Other targeted treatment strategies, such as the PIK3CA inhibitor alpelisib for PIK3CA-mutated vascular malformations, are also emerging. Repurposing of cancer drugs has become a major focus in this rapidly evolving field.

Management of visceral vascular anomalies

Visceral vascular anomalies are common in patients with vascular malformations in other parts of the body and can include lymphatic, venous, and arteriovenous malformations. Depending on the organ or organs involved they may present differently and pose different treatment challenges. Defining the malformation and understanding its extent is paramount in devising management regimens. Medical, interventional, and surgical therapies are often required in combination to treat these complex lesions. There are new and promising advances in the development of therapeutic agents targeting the PI3K/AKT/mTOR pathway. Due to the complex nature of these lesions a coordinated, multi-disciplinary approach is necessary to manage and mitigate symptoms and complications of this diverse group of vascular malformations.

[Clinical effect of sirolimus in treatment of blue rubber bleb nevus syndrome in children: a report of 2 cases and literature review]

To study the clinical effect of oral sirolimus in the treatment of children with blue rubber bleb nevus syndrome (BRBNS) in the gastrointestinal tract, a retrospective analysis was performed on the clinical data and follow-up results of two children with BRBNS treated by sirolimus. The two children with BRBNS had gastrointestinal bleeding and anemia and were treated with sirolimus at a dose of 1 mg/day as part of treatment. The plasma concentration of the drug was maintained between 2.5-12.0 ng/mL. The children showed disappearance of gastrointestinal bleeding and improvements in anemia and coagulation function, and blood transfusion could be stopped during treatment, with no obvious adverse drug reactions. PubMed, Wanfang Data, and CNKI were searched for related articles on sirolimus in the treatment of BRBNS. A total of 26 cases of children with BRBNS, aged 0-18 years, were obtained. With the addition of the 2 cases in this study, sirolimus treatment achieved a satisfactory clinical effect in all 28 cases. Sirolimus may be effective and safe in the treatment of children with BRBNS, and further prospective studies are needed to evaluate the long-term efficacy of this drug.