Hereditary hemorrhagic telangiectasia: arteriovenous malformations in children

Longitudinal Assessment of Curaçao Criteria in Children with Hereditary Hemorrhagic Telangiectasia

OBJECTIVE

To assess the utility of the Curaçao criteria by age over time in children with hereditary hemorrhagic telangiectasia (HHT).

STUDY DESIGN

This was a single-center, retrospective analysis of patients attending the HHT clinic at the Hospital for Sick Children (Toronto, Canada) between 2000 and 2019. The evaluation of the Curaçao criteria was completed during initial and follow-up visits. Screening for pulmonary and brain arteriovenous malformations was completed at 5 yearly intervals.

RESULTS

A total of 116 patients with genetic confirmation of HHT were included in the analysis. At initial screening at a median (IQR) age of 8.4 (2.8, 12.9) years, 41% met criteria for a definite clinical diagnosis (≥3 criteria). In children <6 years at presentation, only 23% fulfilled at least 3 criteria initially. In longitudinal follow-up, 63% reached a definite clinical diagnosis, with a median (IQR) follow-up duration of 5.2 (3.2, 7.9) years (P = .005). Specifically, more patients met the epistaxis and telangiectasia criteria at last visit compared with initial (79% vs 60%; P = .006; 47% vs 30%; P = .02) but not for the arteriovenous malformation criterion (59% vs 57%; P = .65).

CONCLUSIONS

In the pediatric population, most patients do not meet definite clinical criteria of HHT at initial presentation. Although the number of diagnostic criteria met increased over time, mainly due to new onset of epistaxis and telangiectasia, accuracy remained low during follow-up visits. Relying solely on clinical criteria may lead to underdiagnosis of HHT in children.

Comparing Characteristics and Treatment of Brain Vascular Malformations in Children and Adults with HHT

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant disease characterized by the development of vascular malformations (VMs) in organs such as the brain and lungs, as well as telangiectases on mucosal surfaces. Prophylactic treatment of organ VMs may prevent potential complications, such as hemorrhage. However, brain VM treatment-surgical resection, embolization, and/or radiosurgery-is not recommended for all patients due to the associated risks. Given the scarcity of data regarding HHT-related brain VM presentation and treatment trends in pediatric patients, we aim to describe the clinical presentations and the patterns of treatment of HHT-related brain VMs in a pediatric cohort, and compare pediatric trends to those of adults. Demographic and clinical data were analyzed in 114 pediatric patients with HHT-related brain VMs and compared with a cohort of 253 adult patients enrolled in the multicenter Brain Vascular Malformation Consortium HHT Project. Our data demonstrated that a higher proportion of pediatric patients with HHT-related brain VMs were symptomatic at presentation (p = 0.004). Moreover, a higher proportion of pediatric patients presented with intracranial hemorrhage (p < 0.001) and seizure (p = 0.002) compared to adult patients. Surgical resection was the most common brain VM treatment modality in both children and adults. We conclude that pediatric patients may be more likely to present with symptoms and complications from brain VMs, supporting the case for screening for brain VMs in children with HHT.

How we approach localized vascular anomalies

Vascular anomalies are a group of disorders divided into two distinct subtypes: vascular tumors and vascular malformations. Vascular tumors are proliferative in nature, while malformations are nonproliferative. Simple, localized vascular malformations refer to a group of malformations that are localized to a single area of involvement. These simple malformations include capillary, lymphatic, venous, and arteriovenous malformations. The pediatric hematologists and oncologists are becoming increasingly involved in the diagnosis and management of these disorders. This review presents four cases as a means to discuss the diagnosis, clinical and imaging features, and management strategies of simple, localized vascular malformations.

A Rare Case of Hereditary Hemorrhagic Telangiectasia: A Case Report

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is a very rare autosomal dominant genetic disorder that leads to abnormal blood vessel formation in the skin, mucus membranes (called telangiectasia), and organs such as the lung, liver, and brain. It occurs due to a mutation in one of the ACVRL1, ENG, and SMAD4 genes, which code for the formation of blood vessels. The most common symptom is recurring nosebleed (epistaxis; due to rupture of nasal mucosal telangiectasia), which begins in childhood and affects about 90-95% of people with HHT. Other common signs and symptoms include punctate, linear, or splinter-like telangiectasias on the upper body, oral mucosa, or nail beds, gastrointestinal bleeding, and iron deficiency anemia. The diagnostic criteria currently in use are the Curaçao criteria. The diagnosis is made by clinical screening (e.g., history and physical exam), baseline investigations (complete blood count, hemoglobin, hematocrit, and ferritin level), genetic testing, and detailed medical imaging to detect visceral arteriovenous malformations (AVMs) such as esophagogastroduodenoscopy, colonoscopy, multiphase contrast CT, computed tomography angiography (CTA or CT Angio), magnetic resonance angiography (MRA), chest X-ray, Doppler ultrasonography, liver biopsy, and cerebral angiography. Management includes intravenous iron therapy or blood transfusion, antifibrinolytics (e.g tranexamic acid), ablation therapies (e.g. laser treatment, radiofrequency ablation, electrosurgery, sclerotherapy, and argon plasma coagulation), and systemic anti-angiogenic agents (e.g. thalidomide, bevacizumab). In this report, we present the case of a 22-year-old man from Swabi, Pakistan, with a history of recurrent epistaxis (nosebleed) from childhood, who presented with multiple episodes of melena (blood in stool), fatigue, palpitation, and iron deficiency anemia for five years. Multiple esophagogastroduodenoscopies (OGDs) and colonoscopies were done over the years, which showed AVM in the antrum and fundus of the stomach, duodenum, and colon, and a diagnosis of HHT was made. CTA and exploratory laparotomy showed ileal loop hemangiomas. He was managed with multiple blood transfusions, argon plasma coagulation (APC) for the AVMs, oral thalidomide, and steroids. Despite therapy, the patient had intermittent episodes of blood in stool and low blood counts. During his stay in Hayatabad Medical Complex (HMC), the patient was managed with high-frequency blood transfusion and bevacizumab (systemic anti-angiogenic agent). A dramatic reduction in the number of required transfusions and improvement in the patient's bloodlines and symptoms was noted. This case highlights the importance of endoscopic methods for the timely diagnosis of HHT and its management with intravenous bevacizumab.

Nasal Endoscopy in the Clinical Diagnosis of Hereditary Hemorrhagic Telangiectasia

OBJECTIVES

To evaluate the role of nasal endoscopy for early clinical diagnosis of hereditary hemorrhagic telangiectasia (HHT) in children and to investigate the characteristics of epistaxis and mucocutaneous telangiectases in our pediatric population.

STUDY DESIGN

From May 2016 to December 2019, a cross-sectional observational study was conducted, recruiting children aged 2-18 years with a parent affected by HHT. To identify the Curaçao criteria, all children underwent collection of clinical history, mucocutaneous examination, and nasal endoscopy. The clinical data were then compared with the genetic data acquired subsequently.

RESULTS

Seventy children (median age, 10.8 years) were included. All underwent nasal endoscopy without complications. Forty-six children were positive by genetic testing; of these, 26 % had skin and oral telangiectases and 91 % had nasal telangiectases. The diagnostic sensitivity of the Curaçao criteria increased from 28 % (95 % CI, 16%-43 %) to 85 % (95 % CI, 71%-94 %; P < .0001) when the nasal telangiectases were included.

CONCLUSIONS

The magnified and complete endoscopic view of the nasal cavities proved useful in increasing the diagnostic sensitivity of the Curaçao criteria. Such an examination turned out to be feasible and safe. For this reason, we believe that nasal endoscopy should be included in the diagnostic assessment of pediatric patients with suspected HHT.

Characterization of epidemiological distribution and outcome of COVID-19 in patients with hereditary hemorrhagic telangiectasia: a nationwide retrospective multi-centre study during first wave in Italy

Background

Coronavirus Disease 2019 (COVID-19) continues to have a devastating impact across the world. A number of pre-existing common clinical conditions were reported to represent risk factors for more severe COVID-19 outcomes. Hereditary Hemorrhagic Telangiectasia (HHT) is a rare vascular heritable disorders, characterized by complications secondary to visceral Arterio-Venous Malformations. The impact of HHT, as well as for many Rare Diseases (RDs) on infection susceptibility profile and clinical adverse outcome risk is an unresolved issue.

Objectives

The main objectives were: to assess the clinical features and outcomes of HHT patients infected with COVID-19; to compare the relative infection risk in these patients with the Italian general population throughout the first pandemic wave; to investigate the factors potentially associated with severe COVID-19 outcome in HHT patients, and the possible impact of COVID-19 infection on HHT-related symptoms/complications. Finally, we aimed to estimate how the lockdown-associated wearing of personal protective equipment/individual protection devices could affect HHT-related telangiectasia bleeding frequency.

Methods

The study is a nation-wide questionnaire-based survey, with a multi-Center retrospective cross-sectional design, addressed to the whole Italian HHT population. COVID-19 cases, occurring throughout the first pandemic wave, were collected by a questionnaire-based semi-structured interview. Only the cases ascertained by laboratory confirmation (molecular/serological) were included for epidemiological estimates. Information concerning eventual SarS-Cov-2 infection, as well as regarding HHT-related manifestations and HHT-unrelated co-morbidities were collected by the questionnaire. Prevalence data were compared to Italian general population in the same period.

Results

The survey disclosed 9/296 (3.04%) COVID-19 cases, 8/9 of them being resident in Lombardy, the main epidemic epicenter. Pneumonia was reported by 4/9 patients, which prompted hospital admission and intensive care management in 2 cases. No fatal outcome was recorded. After careful refinement of epidemiological analysis, the survey evidenced overlapping infection risk in HHT compared to general population.

Conclusions

COVID-19 infection profile parallels geographical distribution of epidemic foci. COVID-19 in HHT patients can lead to highly variable clinical profile, likely overlapping with that of general population. The HHT disease does not seem to involve a different approach in terms of hospital admission and access to intensive care with respect to general population.

Arteriovenous Malformations-Current Understanding of the Pathogenesis with Implications for Treatment

Arteriovenous malformations are a vascular anomaly typically present at birth, characterized by an abnormal connection between an artery and a vein (bypassing the capillaries). These high flow lesions can vary in size and location. Therapeutic approaches are limited, and AVMs can cause significant morbidity and mortality. Here, we describe our current understanding of the pathogenesis of arteriovenous malformations based on preclinical and clinical findings. We discuss past and present accomplishments and challenges in the field and identify research gaps that need to be filled for the successful development of therapeutic strategies in the future.

Hereditary Hemorrhagic Telangiectasia: The Convergence of Genotype, Phenotype, and Imaging in Modern Diagnosis and Management of a Multisystem Disease

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease that manifests as vascular malformations in the brain, lung, liver, gastrointestinal tract, nasal mucosa, and skin. Diagnosis and management of HHT is guided in large part by imaging studies, making it a condition with which the radiology community needs familiarity. Proper screening and care lead to improved morbidity and mortality in patients with HHT. International guidelines were recently updated and form the basis for a detailed discussion of the role of imaging and image-guided therapy in HHT. © RSNA, 2021 Online supplemental material is available for this article.

Hereditary hemorrhagic telangiectasia presenting as a recurrent epistaxis in an adolescent: A case report

BACKGROUND

Epistaxis can be an isolated finding or a manifestation of a systemic disease. Some of the potential etiologies are usage of anticoagulants, bleeding disorders, vascular aneurysms, nasal neoplasm, hypertension and nasal steroids. Hereditary hemorrhagic telangiectasia (HHT) as a cause of recurrent epistaxis is uncommon.

CASE SUMMARY

In this report, we describe an 18-year-old adolescent with recurrent epistaxis, mucocutaneous telangiectasia and family history of HHT, consistent with HHT.

CONCLUSION

Timely diagnosis is needed not only to treat the epistaxis but also to be vigilant for other serious manifestations of this condition.

Second International Guidelines for the Diagnosis and Management of Hereditary Hemorrhagic Telangiectasia

DESCRIPTION

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease with an estimated prevalence of 1 in 5000 that is characterized by the presence of vascular malformations (VMs). These result in chronic bleeding, acute hemorrhage, and complications from shunting through VMs. The goal of the Second International HHT Guidelines process was to develop evidence-based consensus guidelines for the management and prevention of HHT-related symptoms and complications.

METHODS

The guidelines were developed using the AGREE II (Appraisal of Guidelines for Research and Evaluation II) framework and GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. The guidelines expert panel included expert physicians (clinical and genetic) in HHT from 15 countries, guidelines methodologists, health care workers, health care administrators, patient advocacy representatives, and persons with HHT. During the preconference process, the expert panel generated clinically relevant questions in 6 priority topic areas. A systematic literature search was done in June 2019, and articles meeting a priori criteria were included to generate evidence tables, which were used as the basis for recommendation development. The expert panel subsequently convened during a guidelines conference to conduct a structured consensus process, during which recommendations reaching at least 80% consensus were discussed and approved.

RECOMMENDATIONS

The expert panel generated and approved 6 new recommendations for each of the following 6 priority topic areas: epistaxis, gastrointestinal bleeding, anemia and iron deficiency, liver VMs, pediatric care, and pregnancy and delivery (36 total). The recommendations highlight new evidence in existing topics from the first International HHT Guidelines and provide guidance in 3 new areas: anemia, pediatrics, and pregnancy and delivery. These recommendations should facilitate implementation of key components of HHT care into clinical practice.

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.

Genotype-Phenotype Correlations in Children with HHT

Hereditary hemorrhagic telangiectasia (HHT), a rare autosomal dominant disease mostly caused by mutations in three known genes (ENG, ACVRL1, and SMAD4), is characterized by the development of vascular malformations (VMs). Patients with HHT may present with mucocutaneous telangiectasia, as well as organ arteriovenous malformations (AVMs) of the central nervous system, lungs, and liver. Genotype-phenotype correlations have been well described in adults with HHT. We aimed to investigate genotype-phenotype correlations among pediatric HHT patients. Demographic, clinical, and genetic data were collected and analyzed in 205 children enrolled in the multicenter Brain Vascular Malformation Consortium HHT Project. A chi-square test was used to determine the association between phenotypic presentations and genotype. Among 205 patients (age range: 0-18 years; mean: 11 years), ENG mutation was associated with the presence of pulmonary AVMs (p < 0.001) and brain VM (p < 0.001). The presence of a combined phenotype-defined as both pulmonary AVMs and brain VMs-was also associated with ENG mutation. Gastrointestinal bleeding was rare (4.4%), but was associated with SMAD4 genotype (p < 0.001). We conclude that genotype-phenotype correlations among pediatric HHT patients are similar to those described among adults. Specifically, pediatric patients with ENG mutation have a greater prevalence of pulmonary AVMs, brain VMs, and a combined phenotype.

European Reference Network for Rare Vascular Diseases (VASCERN) position statement on cerebral screening in adults and children with hereditary haemorrhagic telangiectasia (HHT)

Hereditary haemorrhagic telangiectasia (HHT) is a multisystemic vascular dysplasia inherited as an autosomal dominant trait. Approximately 10 % of patients have cerebral vascular malformations, a proportion being cerebral arteriovenous malformations (AVMs) and fistulae that may lead to potentially devastating consequences in case of rupture. On the other hand, detection and treatment related-risks are not negligible, and immediate. While successful treatment can be undertaken in individual cases, current data do not support the treatment of unruptured AVMs, which also present a low risk of bleeding in HHT patients. Screening for these AVMs is therefore controversial.

Structured discussions, distinctions of different cerebrovascular abnormalities commonly grouped into an “AVM” bracket, and clear guidance by neurosurgical and neurointerventional radiology colleagues enabled the European Reference Network for Rare Vascular Disorders (VASCERN-HHT) to develop the following agreed Position Statement on cerebral screening:

1) First, we emphasise that neurological symptoms suggestive of cerebral AVMs in HHT patients should be investigated as in general neurological and emergency care practice. Similarly, if an AVM is found accidentally, management approaches should rely on expert discussions on a case-by-case basis and individual risk-benefit evaluation of all therapeutic possibilities for a specific lesion.

2) The current evidence base does not favour the treatment of unruptured cerebral AVMs, and therefore cannot be used to support widespread screening of asymptomatic HHT patients.

3) Individual situations encompass a wide range of personal, cultural and clinical states. In order to enable informed patient choice, and avoid conflicting advice, particularly arising from non-neurovascular interpretations of the evidence base, we suggest that all HHT patients should have the opportunity to discuss knowingly brain screening issues with their healthcare provider.

4) Any screening discussions in asymptomatic individuals should be preceded by informed pre-test review of the latest evidence regarding preventative and therapeutic efficacies of any interventions. The possibility of harm due to detection of, or intervention on, a vascular malformation that would not have necessarily caused any consequence in later life should be stated explicitly.

We consider this nuanced Position Statement provides a helpful, evidence-based framework for informed discussions between healthcare providers and patients in an emotionally charged area.

Approach to Pulmonary Arteriovenous Malformations: A Comprehensive Update

Pulmonary arteriovenous malformations (PAVMs) are abnormal direct vascular communications between pulmonary arteries and veins which create high-flow right-to-left shunts. They are most frequently congenital, usually in the setting of hereditary hemorrhagic telangiectasia (HHT). PAVMs may be asymptomatic or present with a wide variety of clinical manifestations such as dyspnea, hypoxemia, or chest pain. Even when asymptomatic, presence of PAVMs increases patients' risk of serious, potentially preventable complications including stroke or brain abscess. Transcatheter embolotherapy is considered the gold standard for treatment of PAVMs. Though previous guidelines have been published regarding the management of PAVMs, several aspects of PAVM screening and management remain debated among the experts, suggesting the need for thorough reexamination of the current literature. The authors of this review present an updated approach to the diagnostic workup and management of PAVMs, with an emphasis on areas of controversy, based on the latest literature and our institutional experience.

Pulmonary arteriovenous fistula ruptured in an adolescent girl 1 week after her mother's rupture: a report of a case

A 14-year-old girl was diagnosed with hemothorax associated with pulmonary arteriovenous fistula rupture, and emergency surgery was performed. One week before her surgery, her mother at 32 weeks of gestation underwent emergency surgery for hemothorax caused by pulmonary arteriovenous fistula rupture. Both were diagnosed with hereditary hemorrhagic telangiectasia. The indications for treatment of pulmonary arteriovenous fistulas in young patients remain controversial because the risk of complications concerning pulmonary arteriovenous fistula is lower in young patients than in adult patients. We recommend that aggressive treatment should be performed for pulmonary arteriovenous fistulas in patients with hereditary hemorrhagic telangiectasis with a family history of pulmonary arteriovenous fistula rupture even if the patient is asymptomatic and young, because such patients may have a high risk of pulmonary arteriovenous fistula rupture.

Localization and age distribution of telangiectases in children and adolescents with hereditary hemorrhagic telangiectasia: A retrospective cohort study

BACKGROUND

The location of telangiectases in hereditary hemorrhagic telangiectasia (HHT), as set forth in the consensus diagnostic (Curaçao) criteria, is based primarily on adults.

OBJECTIVE

Document the locations and numbers of telangiectases in a cohort of pediatric patients with HHT.

METHODS

A retrospective chart review using a standardized data collection form for site and number of telangiectases was performed for pediatric patients with HHT (age, 0-18 years) from 2005 to 2016.

RESULTS

Of 90 pediatric patients with HHT, 71% had one or more telangiectases. Of all the telangiectases counted (N = 319), cutaneous telangiectases were more common (73%) than oral telangiectases (27%). The hands were the most frequent site, accounting for 33% of all telangiectases. Adolescents were more likely than children to have cutaneous telangiectases (85% vs 50% [Q = 0.005]). The most frequent sites in children younger than 10 years were the hands excluding the fingers (27%), fingers (25%), and face (23%). Only 23% of subjects (21 of 90) presented with multiple (≥3) telangiectases at locations considered characteristic for the current consensus diagnosis guidelines (lips, oral cavity, and fingers).

LIMITATIONS

Ascertainment bias based on recruitment.

CONCLUSIONS

In this pediatric population, telangiectases at sites not included as "characteristic" by the Curaçao diagnostic criteria were common. The Curaçao criteria in regard to both number and location of telangiectases may be inadequate in the pediatric HHT population.

Comorbidity among HHT patients and their controls in a 20 years follow-up period

Background

Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominant genetic disorder with a wide variety of clinical manifestations due to the presence of multiple arteriovenous malformations in various tissues and organs.

Objective

To study the need for hospital admittance in a group of HHT patients and matched controls during a 20 years follow-up period commencing in 1995.

Methods

All HHT patients in the County of Funen, Denmark, were included. For each patient, three age and sex matched controls were identified at the time of enrolment. Data on all hospitalisations were extracted from the national health registers and compared with clinical records. The hospitalisations were grouped as HHT relevant or not HHT relevant based on the discharge diagnosis (International Classification of Diseases, ICD10) and with particular focus on infections, bleedings and thromboembolic events.

Patients with HHT were compared with controls concerning the first time incidence of each discharge diagnosis.

Results

We included 73 HHT patients and 219 controls of which one control was lost to follow-up. HHT-patients had significantly more hospitalisations per person caused by infections in joints and bones, but not caused by infections in general. Bleeding episodes were, as expected, more frequent among the HHT-patients. The study revealed a similar incidence of abscesses and thromboembolisms, including in the central nervous system, among the HHT patients and controls.

Conclusions

Based on this study Danish HHT patients had an increased comorbidity of infections in joints and bones and of bleeding episodes. However, the incidence of thromboembolisms, cerebral abscesses and other conditions commonly considered related to HHT was comparable between the patients and the controls. The patients included in this study were closely monitored at a highly specialised HHT Centre where they received relevant diagnostic evaluation, treatment and counselling. Since this is assumed to benefit the overall health of the patients, it may explain why these patients were less prone to comorbidity than other studies have suggested.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0962-8) contains supplementary material, which is available to authorized users.

A Pial Arteriovenous Fistula in Infancy as the Presenting Manifestation of Hereditary Hemorrhagic Telangiectasia

BACKGROUND

Pial arteriovenous fistulas (PAVFs) are rare, accounting for 1.6%-4.7% of all intracranial vascular malformations. Often diagnosed in childhood, about 30% are associated with hereditary hemorrhagic telangiectasia. A case of PAVF diagnosed soon after birth and given cerebrovascular therapy 4 months after birth is reported.

CASE DESCRIPTION

The patient presented with heart failure immediately after birth. Ultrasonography of the head showed abnormal blood flow in the brain. On digital subtraction angiography performed 4 months after birth, a PAVF with a dural feeder shunt and a giant varix at the posterior temporal part was confirmed. After transarterial embolization (TAE), shunt blood flow disappeared. New shunt flow from the right posterior cerebral artery into the varix was confirmed by magnetic resonance imaging 3 months after the operation. A second TAE procedure using a liquid embolic material was performed and confirmed the complete disappearance of the shunt.

CONCLUSIONS

This report describes a case of infant PAVF with heart failure, a giant varix, hydrocephalus, and intraventricular hemorrhage treated by TAE using platinum coils and liquid embolic material.

Pulmonary arteriovenous malformations in children with hereditary hemorrhagic telangiectasia: a longitudinal study

Pulmonary arteriovenous malformations (PAVMs) often occur in children with hereditary hemorrhagic telangiectasia (HHT). A 14-year longitudinal study of PAVMs in children with HHT was undertaken to assess the prevalence, the clinical impact, and progression of these malformations. This was a retrospective, single-center study from May 2002 to December 2016 of 129 children with HHT diagnosed using Curacao criteria and/or confirmed by genetic testing. Transthoracic contrast echocardiography (TTCE) was the primary screening modality in all patients and PAVMs were diagnosed based on Barzilai criteria. Moderately positive TTCE (Barzilai criteria ≥ 2) was confirmed with subsequent contrast chest CT. New PAVMs were diagnosed with a positive TTCE after an initial negative TTCE. Embolization of PAVMs were performed according to HHT consensus guidelines. Of 129 children with HHT, 76 (59%) were found to have PAVMs. Sixty-seven (88%) were positive for PAVMs on initial screening. Of 63 children without PAVMs on initial screening, 31 were followed for >1 year. Nine of the 31 (29%) developed new PAVMs after initial negative study. Thirty-eight (50%) of the total 76 children with PAVMs had or developed lesions large enough to be treated with embolization. Nine patients with PAVMs initially too small to be treated with embolization, developed progression of disease and ultimately were treated with embolization over time. The majority, 60% (23/38), of the children with large PAVMs had no related clinical symptoms. After embolization, 21% (8/38), of patients underwent repeat interventions. Genetic diagnosis, age, and gender were not associated with risk of having PAVM nor with need for repeat interventions. Nearly 60% of children with HHT develop PAVMs. The risk for new PAVMs to develop, small PAVMs to become large, and previously embolized PAVMs to require further intervention remains throughout childhood. Thus, children with HHT require continued follow-up until adulthood.

Applicability of the Curaçao Criteria for the Diagnosis of Hereditary Hemorrhagic Telangiectasia in the Pediatric Population

OBJECTIVE

To evaluate the accuracy of the clinical Curaçao criteria in the diagnosis of hereditary hemorrhagic telangiectasia (HHT) in children and adolescents.

STUDY DESIGN

This was a retrospective, multicenter chart review of 673 patients evaluated between 2002 and 2016; 290 were eligible for the study. Genetic testing for a pathogenic mutation was considered the gold standard against which the clinical Curaçao criteria were compared. Patients were divided into 4 age categories: 0-5, 6-10, 11-15, and 16-21-years. Sensitivity and specificity were calculated for each age group, and for the overall population.

RESULTS

Overall the Curaçao criteria had a sensitivity of 68% (95% CI 60%-76%) and a specificity of 98% (95% CI 91%-100%). Sensitivity was lowest in the 0- to 5-year group, and increased with advancing age. The Curaçao criteria had the highest sensitivity in the 16- to 21-year-olds. Specificity was 100% in all age groups except for the 11- to 15-year-olds.

CONCLUSIONS

This study evaluated the use of the Curaçao criteria for the diagnosis of HHT in the pediatric population with a family history of HHT. In those between the age of 0 and 21 years who meet 1 criterion (unlikely HHT) or 2 criteria (possible HHT), genetic testing is preferred for diagnosis. The Curaçao criteria appear to reliably diagnose HHT in children and adolescents who meet 3 or 4 criteria (definite HHT).

The concept of type 2 segmental mosaicism, expanding from dermatology to general medicine

In autosomal dominant skin disorders, the well-known type 1 segmental mosaicism reflects heterozygosity for a postzygotic new mutation. By contrast, type 2 segmental mosaicism originates in a heterozygous embryo from an early postzygotic mutational event giving rise to loss of the corresponding wild-type allele, which results in a pronounced segmental involvement being superimposed on the ordinary, non-segmental phenotype. Today, this concept has been proven by molecular analysis in many cutaneous traits. The purpose of this review was to seek publications of cases suggesting an extracutaneous manifestation of type 2 segmental mosaicism. Case reports documenting a pronounced extracutaneous segmental involvement were collected from the literature available in PubMed and from personal communications to the author. Pertinent cases are compared to the description of cutaneous segmental mosaicism of type 1 or type 2 as reported in a given trait. In total, reports suggesting extracutaneous type 2 segmental mosaicism were found in 14 different autosomal dominant skin disorders. In this way, clinical evidence is accumulated that extracutaneous type 2 segmental mosaicism does likewise occur in many autosomal dominant skin disorders. So far, however, molecular proof of this particular form of mosaicism is lacking. The present review may stimulate readers to inform colleagues of other specialties on this new concept, in order to initiate further research in this particular field of knowledge that has important implications for diagnosis, treatment and genetic counselling.

Angioarchitecture of Hereditary Arteriovenous Malformations

This article describes three hereditary conditions known to be associated with arteriovenous malformation (AVM), along with their clinical and imaging features and angiographic angioarchitecture. Hereditary hemorrhagic telangiectasia, capillary malformation-AVM (CM-AVM), and PTEN tumor hamartoma syndrome are conditions with autosomal dominant inheritance, caused by mutations in different molecular pathways, which frequently present with symptomatic AVMs. Imaging biomarkers, including sites of predilection, angioarchitecture, and tissue overgrowth patterns, are helpful in identifying these patients and selecting appropriate treatment.

Asymptomatic pulmonary arteriovenous malformations in children with hereditary hemorrhagic telangiectasia

BACKGROUND

Children with Hereditary Hemorrhagic Telangiectasia (HHT) may have pulmonary arteriovenous malformations (AVMs), which can lead to symptoms of shortness of breath, exercise intolerance, clubbing, cyanosis and hemoptysis. However, some patients with pulmonary AVMs may be asymptomatic, placing them at risk for complications such as stroke or brain abscess if they are not identified and treated. This study examines the incidence of signs and symptoms associated with pulmonary AVMs in children with HHT known to have pulmonary AVMs.

METHOD

Sixty-one children with HHT and documented pulmonary AVMs were questioned for any symptoms possibly associated with their pulmonary AVMs, prior to embolization.

RESULTS

The results show that the majority of these children were asymptomatic (56%), and their AVMs were discovered by routine screening. Those who did experience symptoms most often complained of shortness of breath and exercise intolerance, although there was a tendency to blame other conditions, such as asthma or deconditioning (being out of shape), for these symptoms. Migraine headaches were common in those with pulmonary AVMs, regardless of whether they were symptomatic or not (17 of 61 children, 28%), although they were more common in those who were symptomatic (10 of 27, 37%) versus those who were asymptomatic (7 of 34, 21%).

CONCLUSION

Children with HHT and pulmonary AVMs are often asymptomatic. Routine screening for the presence of AVMs should be performed regardless of symptomatology.

Screening children for pulmonary arteriovenous malformations: Evaluation of 18 years of experience

BACKGROUND

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disease with multi-systemic vascular dysplasia. Early diagnosis through screening is important to prevent serious complications. How best to screen children of affected parents for pulmonary arteriovenous malformations (PAVMs) is often subject to debate. Transthoracic contrast echocardiogram (TTCE) is considered optimal in screening for PAVMs in adults. Guidelines for the screening of children are not specific, reflecting the lack of scientific evidence on the best method to use.

OBJECTIVE

Aims of this study are (i) to evaluate our current screening method, consisting of history, physical examination, pulse oximetry, and chest radiography and (ii) to assess whether postponing more invasive screening for PAVMs until adulthood is safe.

METHODS

This is a prospective observational cohort study using a patient database.

RESULTS

Over a period of 18 years (mean follow-up 9.21 years, SD 4.72 years), 436 children from HHT families were screened consecutively. A total of 175/436 (40%) children had a diagnosis of HHT. PAVMs were detected in 39/175 (22%) children, 33/39 requiring treatment by embolotherapy. None of the screened children suffered any PAVM-associated complications with this screening method.

CONCLUSION

This study shows that a conservative screening method during childhood is sufficient to detect large PAVMs and protect children with HHT for PAVM-related complications. Postponing TTCE and subsequent chest CT scanning until adulthood to detect any smaller PAVMs does not appear to be associated with major risk.

Cerebral hemorrhage in monozygotic twins with hereditary hemorrhagic telangiectasia: case report and hemorrhagic risk evaluation

The authors present a case of monozygotic twins with hereditary hemorrhagic telangiectasia (HHT) who experienced cerebral arteriovenous malformation (AVM) hemorrhage at a very young age. The clinical variables influencing HHT-related AVM rupture are discussed, and questions surrounding the timing of screening and intervention are explored. This is only the second known case of monozygotic HHT twins published in the medical literature, and the youngest pair of first-degree relatives to experience AVM-related cerebral hemorrhage. Evidence guiding the screening and management of familial HHT is lacking, and cases such as this underscore the need for objective and validated protocols.

Non-invasive CT screening for pulmonary arteriovenous malformations in children with confirmed hereditary hemorrhagic telangiectasia: Results from two pediatric centers

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder that is caused by mutations in mainly two genes, that is ENG, encoding endoglin (HHT1), or ACVRL1, encoding activin receptor-like kinase 1 (ALK-1/HHT2). HHT is characterized by recurrent epistaxis, mucocutaneous telangiectasia, and vascular visceral dysplasia responsible for visceral arteriovenous malformations (AVM).

AIM

to report the experience of two university hospitals (Trousseau, Paris, and CHIC, Creteil) with screening children for HHT and pulmonary AVM (PAVM) using high resolution computed tomography (HRCT).

METHODS

parents with confirmed HHT were offered to have their children screened for the mutation identified in their family, and informed consent was obtained. Children carrying the same mutation as their parents underwent HRCT of the chest without contrast.

RESULTS

between 2008 and 2015, 99 children were screened for HHT mutations. Mutations were identified in 59 patients, that is 24 HHT1 and 35 HHT2. Radiologic and clinical screening was possible in 52 patients (21 HHT-1 and 31 HHT-2). Among those, PAVM was identified in 13 patients (25%; n = 8 HHT1; n = 5 HHT2), and four of them required embolization therapy.

CONCLUSION

This study highlights the usefulness of genetic screening in children with known HHT family. It also suggests that a non-invasive protocol such as HRTC is an efficient approach to detect non-symptomatic lesions that are present early on in children carrying the ENG (HHT1), but also the ACVRL1 mutations (HHT2). Pediatr Pulmonol. 2017;52:642-649. © 2017 Wiley Periodicals, Inc.

Hereditary haemorrhagic telangiectasia: to transplant or not to transplant?

The Association of hereditary hemorrhagic telangiectasia (HHT) and type I hereditary angioedema is a very rare condition in medicine. The case reported by Muller et al., describes the coexistence of the two diseases and emphasizes the need for listing HHT patients for liver transplantation in case indications occurs, such as the presence of HCC, abnormally increased cardiac output, and gastrointestinal bleeding as reported for this case. The case described by Mueller et al. is anecdotal for the usefulness of liver transplantation in HHT patients and shows that liver transplantation may be the best supportive care and, sometimes, the unique and final therapeutic option for these patients.

Prevalence and characteristics of brain arteriovenous malformations in hereditary hemorrhagic telangiectasia: a systematic review and meta-analysis

OBJECTIVE Patients with hereditary hemorrhagic telangiectasia (HHT) are known to suffer from high rates of cerebral arteriovenous malformations (AVMs). The authors performed a systematic review and meta-analysis of the literature examining prevalence rates, characteristics, and clinical presentation of cerebral AVMs in the HHT population. METHODS To identify studies on AVM prevalence and characteristics in the HHT population, 4 databases (MEDLINE, EMBASE, Scopus and Web of Science) were searched by a reference librarian with over 30 years experience in systematic reviews and meta-analysis. The search period was January 1, 1990-March 2016. The following search terms were used: hereditary hemorrhagic telangiectasia, Osler-Weber-Rendu syndrome, AVM, brain AVM, arteriovenous malformation, arteriovenous fistula, prevalence, and epidemiology. The authors identified studies that examined the prevalence rates, characteristics, and clinical presentation of cerebral AVMs in patients with HHT. They assessed overall AVM prevalence rates as well as prevalence rates by age, sex, HHT type, and country/region. They also systematically reviewed the characteristics of AVMs, including rupture status, location, clinical presentation, angioarchitecture, and Spetzler-Martin grade. Data were analyzed using a random-effects meta-analysis model. RESULTS Thirty-nine studies were included in this meta-analysis. Thirty studies examined brain AVM prevalence rates in various HHT patient populations, and 18 studies examined AVM clinical and angiographic characteristics (9 studies examined both prevalence rates and AVM characteristics). The prevalence of brain AVMs in HHT patients was 10.4% (95% CI 7.9%-13.0%) with no significant difference between males (8.5%, 95% CI 4.9%-12.0%) and females (11.0%, 95% CI 5.9%-16.1%). Patients with HHT Type 1 (HHT1) had a significantly higher brain AVM prevalence (13.4%, 95% CI 9.5%-17.4%) compared with those with HHT Type 2 (HHT2) (2.4%, 95% CI 1.0%-3.8%) (p < 0.0001). In 55.2% (95% CI 38.3%-72.1%) of cases, the AVMs were symptomatic. Spetzler-Martin grade was 2 or less in 86.9% (95% CI 67.5%-95.2%) of patients. CONCLUSIONS The prevalence of brain AVMs in the HHT population is about 10%. HHT1 patients are significantly more likely to have brain AVMs than HHT2 patients. Most AVMs in the HHT population are symptomatic. The Spetzler-Martin grade for these lesions is 2 or less in nearly 90% of patients.

Life expextancy of parents with Hereditary Haemorrhagic Telangiectasia

Background

Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominant disease associated with epistaxis, arteriovenous malformations and telangiectasias. Disease complications may result in premature death.

Method

We investigated life-expectancies of parents of HHT patients compared with their non-HHT partners using self- or telephone-administered questionnaires sent to their children. Patients were extracted from the databases of 2 participating HHT Centres: the Toronto HHT Database (Toronto, Canada) and the St. Antonius Hospital HHT Database (Nieuwegein, The Netherlands).

Results

Two hundred twenty five/407 (55 %) of respondents were included creating HHT- (n = 225) and control groups (n = 225) of equal size. Two hundred thirteen/225 (95 %) of the HHT group had not been screened for organ involvement of the disease prior to death. The life expectancy in parents with HHT was slightly lower compared to parents without (median age at death 73.3 years in patients versus 76.6 years in controls, p0.018). Parents with ACVRL 1 mutations had normal life expectancies, whereas parents with Endoglin mutations died 7.1 years earlier than controls (p = 0.024). Women with Endoglin mutations lived a median of 9.3 years shorter than those without (p = 0.04). Seven/123 (5 %) of deaths were HHT related with a median age at death of 61.5 years (IQ range 54.4–67.7 years).

Conclusion

Our study showed that the life expectancy of largely unscreened HHT patients was lower than people without HHT. Female patients with Endoglin mutations were most strikingly at risk of premature death from complications. These results emphasize the importance of referring patients with HHT for screening of organ involvement and timely intervention to prevent complications.

Pulmonary vascular complications of hereditary haemorrhagic telangiectasia. Curr Opin Pulm Med. 2014;20:421-428. [PMID: 25032812 DOI: 10.1097/mcp.0000000000000076]

PURPOSE OF REVIEW

The purpose of this study is to present the latest advances and recommendations in the diagnosis and treatment of pulmonary vascular complications associated with hereditary haemorrhagic telangiectasia (HHT): pulmonary arteriovenous malformations (PAVMs), pulmonary arterial hypertension (PAH), pulmonary hypertension associated with high output cardiac failure or liver vascular malformations, haemoptysis, haemothorax and thromboembolic disease.

RECENT FINDINGS

Transthoracic contrast echocardiography has been validated as a screening tool for PAVM in patients with suspected HHT. Advancements in genetic testing support its use in family members at risk as a cost-effective measure. Therapy with bevacizumab in patients with high output cardiac failure and severe liver AVMs showed promising results. PAH tends to be more aggressive in HHT type 2 patients.

SUMMARY

Patients suffering from this elusive disease should be referred to HHT specialized centres to ensure a standardized and timely approach to diagnosis and management.

Hereditary Hemorrhagic Telangiectasia presenting as migraine: a case report

BACKGROUND

Hemorrhagic Hereditary Telangiectasia (HHT) is an autosomal dominant disease characterized by the presence of multiple arteriovenous malformations (AVMs). Migraine is described in association with HHT in adulthood, while only few paediatric cases are reported in the literature.

AIM

In this paper, we describe an atypical case of HHT in a 7-year-old boy, who presented severe and recurrent episodes of migraine-like headache as the first symptom of the disease.

METHODS

The patient was accurately investigated both clinically (general, neurological and dermatological examinations), instrumentally (electroencephalogram, brain magnetic resonance, transcranic Eco-color-Doppler, contrast echocardiography and enhanced chest computed tomography) and genetically.

RESULTS

Familial history was positive for HHT in the paternal line. Both general and neurological examination were normal. Brain magnetic resonance imaging showed a minor old infarct in the right parietal and occipital lobes. Transcranic Eco-color-Doppler, contrast echocardiography and enhanced chest computed tomography revealed a pulmonary AVM. Cephalalgia resolved after transcatheter embolotherapy. A genetic test, identifying the mutation in endoglin gene both in the patient and in the father, confirmed the suspected diagnosis of HHT.

CONCLUSIONS

Although headache is rarely reported in children as the first symptom of HHT, we warn clinicians on this possible link, as a promptly diagnosis is advisable in order to prevent potential complications.

Pulmonary Arteriovenous Malformations and Cerebral Abscess Recurrence in a Child With Hereditary Hemorrhagic Telangiectasia

BACKGROUND

A 17-year-old boy was referred to our center with a history of brain abscess (BA) recurring after 9 years. The patient reported 2 previous treatments for pulmonary arteriovenous malformations, sporadic nosebleeds, and familial history for epistaxis. Clinical investigations revealed arteriovenous malformations in lung, brain, and liver, as well as mucocutaneous telangiectases. A definite diagnosis of hereditary hemorrhagic telangiectasia was made based on clinical criteria and confirmed by genetic analysis. This is the first report of BA recurrence at the end of pediatric age.

CONCLUSIONS

The present case and the literature review of all cases of BA thus far reported highlight the need to raise the suspicion of a pulmonary arteriovenous malformations, both isolated and in the context of a possible hereditary hemorrhagic telangiectasia, for any case of BA of unexplained etiology, in children as well as in adults.

Management of visceral vascular anomalies

Vascular malformations affect the viscera less commonly than the head and neck, extremities, and extra-cavitary soft tissues. They present with a wide spectrum of symptoms and findings including pain, respiratory compromise, hemoptysis, chylothorax, ascites, gastrointestinal bleeding, and obstruction. Management options depend upon the subtype of malformation and anatomic extent and may include sclerotherapy, embolization, surgical extirpation, coloanal pull-through, and occasionally more innovative individualized surgical approaches.

Targeting under-diagnosis in hereditary hemorrhagic telangiectasia: a model approach for rare diseases?

Background

Hereditary hemorrhagic telangiectasia (HHT), a rare autosomal dominant disease, is considered under-diagnosed. Our primary objective was to provide evidence of under-diagnosis of HHT in a North American population. We hypothesized that variation would exist in the diagnosed prevalence (D-prevalence) across regions in the province of Ontario, Canada and across age groups, due to under-diagnosis in certain groups. Our secondary objective was to collect data regarding contact and local access to consult specialists by HHT patients to help guide potential future diagnostic programs.

Methods

Primary objective- 556 adult patients with a definite HHT diagnosis seen at the Toronto HHT Centre were identified and geocoded with postal codes. Prevalence rates were calculated using Canadian census data. Secondary objective- A driving network model was developed in ArcGIS. Service area buffers around ear, nose and throat (ENT) clinics in Ontario were generated to evaluate the proportion of the Ontario population with access to these clinics. A survey was also sent to the email contact list of HHT Foundation International, targeting people with diagnosed HHT, regarding consultation with ENT physicians for epistaxis and timing of HHT diagnosis.

Results

Primary objective- D-prevalence rates varied among regions, from no cases to 1.1 cases per 5000 in large Ontario cities. There were no significant differences between urban and rural prevalence rates. Variation in prevalence was seen across age groups, with greater prevalence in older adults (≥50 years-old) compared with adults 20–49 years-old (0.36 versus 0.26 per 5000, p < 0.0005). Secondary objective- Most Ontarians had access to ENT clinics within a 30, 60 and 90 minute modeled drive time (92.7%, 97.8% and 98.6%, respectively). Nearly 40% of surveyed patients consulted an ENT physician for their epistaxis, on average 13.9 ± 12.2 years prior to being diagnosed with HHT.

Conclusions

The prevalence of HHT in Ontario is highly variable across regions and age-groups, suggesting under-diagnosis. Given that patients with HHT frequently consult ENT physicians for epistaxis prior to HHT diagnosis, and that there is almost universal access to ENTs in Ontario, we propose targeting ENT clinics as a province-wide approach to detect undiagnosed HHT patients and families.

The diagnostic yield of rescreening for arteriovenous malformations in children with hereditary hemorrhagic telangiectasia

The diagnostic yield of rescreening children with hereditary hemorrhagic telangiectasia at regular intervals for arteriovenous malformations is unclear. Here, we show that when children with initially negative screening were reassessed after 5 years, no new arteriovenous malformations were detected suggesting that longer intervals between screenings may be adequate.

Reliability of contrast echocardiography to rule out pulmonary arteriovenous malformations and avoid CT irradiation in pediatric patients with hereditary hemorrhagic telangiectasia

BACKGROUND

The overall risk of cancer is higher in people exposed to computed tomography (CT) scans in childhood or adolescence compared to adults. Transthoracic contrast echocardiography (TTCE) has recently been used to screen for pulmonary arteriovenous malformations (PAVMs) in children with hereditary hemorrhagic telangiectasia (HHT), but the value of TTCE to rule out PAVMs and avoid chest CT radiation has yet to be discussed.

METHODS

Between 2003 and 2013, 92 pediatric patients with ≥3 Curaçao criteria and/or genetic mutation underwent TTCE and chest CT on the same day. We used the classification proposed by Barzilai for TTCE quantification of shunting. We considered CT findings as negative when no PAVMs or only one microscopic PAVM was detected.

RESULTS

Mean age was 11.2 ± 4.1 years. The shunt was grade 0 on TTCE in 27.3%, grade 1 in 17%, grade 2 in 29.6%, grade 3 in 23.9%, and grade 4 in 2.2%. We found PAVMs on chest CT in 52.2%. All the patients with a grade 0 or 1 had a negative CT. The sensitivity and specificity of TTCE for the detection of PAVMs were 100% and 95.1%, respectively. The negative predictive value (NPV) was 100% and the positive predictive value (PPV) was 96%.

CONCLUSIONS

A low-grade classification (Barzilai 0 or 1) could presumably exclude the presence of PAVMs and allow CT irradiation to be avoided in children and adolescents. The screening algorithm using TTCE first would allow more than 40% of the pediatric patients screened for PAVMs to be spared the radiation dose of CT.

[What’s new in pediatric dermatology?]

This article is a selection of the most significant developments in the field of pediatric dermatology through an analysis of the articles published between October 2012 and October 2013. In the field of vascular anomalies, propranolol remains a topic of interest for infantile hemangiomas. New clinical concepts appear in the field of vascular malformations in parallel to genetic progress in this area. New epidemiological data or new pathophysiological concepts apply to atopic dermatitis. Congenital or atypical nevi of the child benefit from genetic progress or improvement of clinical knowledge. Although rare, melanoma of the child concerns by its increasing incidence and its misleadingclinical characteristics. Other data reported here relate to infectious skin of the child, morpheas, neurofibromatosis type 1, psoriasis and other commonly seen dermatoses in children.