Hereditary Hemorrhagic Telangiectasia

Hereditary haemorrhagic telangiectasias with recurrent ischemic stroke hinted by manganese deposition in the basal ganglia: a case report and literature review

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant inherited vascular disorder that can involve multiple organs, thus can be associated with so many clinical departments that proper screening and diagnosis of HHT are needed for providing better management of both patients and their family members.

CASE PRESENTATION

We present a 58-year-old female patient with recurrent paradoxical brain embolism due to HHT. She received aspirin therapy and underwent pulmonary arteriovenous malformation embolization, recovering well and discharged 3 days postoperatively. Though ischemic stroke caused by HHT-induced vascular disorders has been reported, our patient presented with both recurrent paradoxical brain embolisms and radiologic findings of bilateral globus pallidus manganese deposition at the same time, a combination rarely reported. We also review the literature on the clinical features and management of HHT for prompt diagnosis of this genetic disease behind paradoxical embolism.

CONCLUSIONS

When patients with ischemic stroke, especially recurrent ischemic stroke, have combined arteriovenous malformations (AVMs) in single or multiple organs, or clues for AVMs like manganese deposition in globus pallidus, genetic diseases such as HHT may be the reason for ischemic stroke and shouldn't be missed in the evaluation of embolic sources.

Antithrombotic therapy for atrial fibrillation in hereditary hemorrhagic telangiectasia

Antithrombotic therapy reduces stroke risk in patients with atrial fibrillation but at the cost of increased bleeding risk. Patients with hereditary hemorrhagic telangiectasia (HHT) are at increased bleeding risk due to fragile mucocutaneous telangiectasias and visceral arteriovenous malformations. These patients are simultaneously at elevated thrombotic risk due to the vascular abnormalities of HHT. Managing atrial fibrillation in patients with HHT represents an understudied and challenging clinical scenario. We present a retrospective cohort study investigating antithrombotic therapy in patients with HHT and atrial fibrillation. We found that antithrombotic therapy was poorly tolerated, leading to premature dose-reduction or discontinuation of therapy in a majority of patients and in a majority of treatment episodes. Five patients undergoing left atrial appendage procedures did well despite difficulties completing the prescribed course of post-procedure antithrombotic therapy. Left atrial appendage occlusion or simultaneous administration of systemic anti-angiogenic therapy may represent alternatives but require additional study in patients with HHT.

An Overview of Clinical Manifestations of Dermatological Disorders in Intensive Care Units: What Should Intensivists Be Aware of?

Acute skin failure is rarely the primary diagnosis that necessitates admission to an intensive care unit. Dermatological manifestations in critically ill patients, on the other hand, are relatively common and can be used to make a key diagnosis of an adverse drug reaction or an underlying systemic illness, or they may be caused by factors related to a prolonged stay or invasive procedures. In intensive care units, their classification is based on the aetiopathogenesis of the cutaneous lesion and, in the meantime, distinguishes critical patients. When evaluating dermatological manifestations, several factors must be considered: onset, morphology, distribution, and associated symptoms and signs. This review depicts dermatological signs in critical patients in order to lay out better recognition.

Whole-Exome Sequencing Reveals Pathogenic SIRT1 Variant in Brain Arteriovenous Malformation: A Case Report

Arteriovenous malformations of the brain (bAVMs) are plexuses of pathological arteries and veins that lack a normal capillary system between them. Intracranial hemorrhage (hemorrhagic stroke) is the most frequent clinical manifestation of AVM, leading to lethal outcomes that are especially high among children and young people. Recently, high-throughput genome sequencing methods have made a notable contribution to the research progress in this subject. In particular, whole-exome sequencing (WES) methods allow the identification of novel mutations. However, the genetic mechanism causing AVM is still unclear. Therefore, the aim of this study was to investigate the potential genetic mechanism underlying AVM. We analyzed the WES data of blood and tissue samples of a 30-year-old Central Asian male diagnosed with AVM. We identified 54 polymorphisms in 43 genes. After in-silica overrepresentation enrichment analysis of the polymorphisms, the SIRT1 gene variant (g.67884831C>T) indicated a possible molecular mechanism of bAVM. Further studies are required to evaluate the functional impact of SIRT1 g.67884831C>T, which may warrant further replication and biological investigations related to sporadic bAVM.

Hereditary Hemorrhagic Telangiectasia: Genetics, Pathophysiology, Diagnosis, and Management

Hereditary hemorrhagic telangiectasia is an inherited disease related to an alteration in angiogenesis, manifesting as cutaneous telangiectasias and epistaxis. As complications, it presents vascular malformations in organs such as the lung, liver, digestive tract, and brain. Currently, diagnosis can be made using the Curaçao criteria or by identifying the affected gene. In recent years, there has been an advance in the understanding of the pathophysiology of the disease, which has allowed the use of new therapeutic strategies to improve the quality of life of patients. This article reviews some of the main and most current evidence on the pathophysiology, clinical manifestations, diagnostic approach, screening for complications, and therapeutic options, both pharmacological and surgical.

Pulmonary arteriovenous malformation and inherent complications with solitary lung nodule biopsy—literature overview and case report

Pulmonary arteriovenous malformation, also known as an arteriovenous fistula, is typically a congenital disease caused by structural deficiencies, particularly the lack of capillary wall development, leading to the abnormal dilation of the pulmonary capillaries. The majority of pulmonary arteriovenous malformation cases are associated with Rendu–Osler–Weber syndrome, also known as hereditary hemorrhagic telangiectasia. Pulmonary arteriovenous malformation rarely occurs due to chest trauma. Pulmonary arteriovenous malformations are long-lasting and often first diagnosed in adults. More than two-thirds of pulmonary arteriovenous malformation lesions are found in the lower lung lobe and the subpleural area, and the vast majority of cases present with the monofocal form. The initial diagnosis is often based on the identification of a solitary pulmonary nodule. However, a solitary nodule detected on chest computed tomography that is not correctly diagnosed as pulmonary arteriovenous malformation, even after intravenous contrast injection, can lead to the performance of a transthoracic biopsy. Biopsy of pulmonary arteriovenous malformations can lead to stroke occurrence, during which the patient often presents with severe pleural bleeding, which can have lifelong consequences if not immediately treated. We report a case of pulmonary arteriovenous malformation that was discovered incidentally in an adult patient who underwent non-contrast computed tomography. Misdiagnosis occurred, and transthoracic lung biopsy was performed. Complications were discovered late, and the patient underwent surgical pulmonary arteriovenous malformation removal and was treated for hemothorax.

Pazopanib for severe bleeding and transfusion-dependent anemia in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a rare angiogenic disorder causing chronic gastrointestinal bleeding, epistaxis, and severe anemia. Pazopanib is an oral multi-kinase angiogenesis inhibitor with promise to treat bleeding in HHT. We analyzed outcomes of HHT patients with the most severe bleeding causing RBC transfusion dependence treated on a predefined institutional pazopanib treatment pathway (with data collected retrospectively). The primary endpoint was achievement of transfusion independence. Secondary endpoints included hemoglobin, epistaxis severity score, RBC transfusion and iron infusion requirements, number of local hemostatic procedures, ferritin and transferrin saturation, compared using paired and repeated measures mean tests. Thirteen transfusion-dependent HHT patients received pazopanib [median (range) dose 150 (25–300) mg daily)] for a median of 22 months. All patients achieved transfusion independence. Compared with pretreatment, pazopanib increased mean hemoglobin by 4.8 (95% CI, 3.6–5.9) g/dL (7.8 vs. 12.7 g/dL, P < 0.0001) and decreased mean epistaxis severity score by 4.77 (3.11–6.44) points (7.20 vs. 2.43 points, P < 0.0001) after 12 months of treatment. Compared with 3 months of pretreatment, RBC transfusions decreased by 93% (median of 16.0 vs. 0.0 units, P < 0.0001) and elemental iron infusion decreased by 92% (median of 4500 vs. 0 mg, P = 0.005) during the first 3 months of treatment; improvements were maintained over time. Pazopanib was well-tolerated: hypertension, lymphocytopenia, and fatigue were the most common TEAEs. In conclusion, pazopanib was safe and effective to manage severe bleeding in HHT, liberating all patients from transfusion dependence and normalizing hematologic parameters at doses lower than used to treat malignancies. These findings require confirmation in a randomized trial.

Sclerotherapy Versus Cautery/Laser Treatment for Epistaxis in Hereditary Hemorrhagic Telangiectasia

OBJECTIVES/HYPOTHESIS

Surgical interventions for epistaxis management in hereditary hemorrhagic telangiectasia (HHT) demonstrate short-term success and require repeated procedures for disease control. Although electrocautery and/or laser photocoagulation (C ± L) are most frequently performed, sodium tetradecyl sclerotherapy (STS) is emerging as a promising newer treatment. We hypothesized that in a 24-month time period, STS would require fewer treatments than C ± L to maintain epistaxis severity within the mild range.

STUDY DESIGN

Retrospective study.

METHODS

We retrospectively assessed 67 patients with HHT with moderate and severe epistaxis that were treated periodically with C ± L (34 patients) versus STS (33 patients). The primary outcome was the number of procedures needed to maintain the epistaxis severity score (ESS) as mild. Secondary outcomes assessed for differences in postoperative complications, hemoglobin levels, iron stores, hematologic support, and quality-of-life (QoL) scores.

RESULTS

To maintain ESS in the mild range, 1.6 STS procedures (range, 1-4) were performed versus 3.6 C ± L procedures (range, 1-8) (P = .003). Significant postoperative differences included reduction in nasal crusting (3% vs. 32%, P = .001), foul odor (3% vs. 35%, P < .001), and septal perforation (3% vs. 29%, P = .006) after STS. There were no significant differences between the two treatments in hemoglobin levels, iron stores, hematologic support, or QoL scores.

CONCLUSION

STS is able to attain satisfactory epistaxis control with significantly fewer procedures and lower postoperative complications than C ± L. STS should be considered as the initial surgical intervention for epistaxis in patients with HHT.

LEVEL OF EVIDENCE

IV Laryngoscope, 2021.

[Hereditary hemorrhagic telangiectasia: a report of two cases]

This article reports two children with hereditary hemorrhagic telangiectasia (HHT). Patient 1 was a boy aged 12 years and was admitted due to intermittent cough and wheezing for more than 10 years. This boy and his mother and grandmother had a history of epistaxis. The boy had a history of the rupture of cerebral arteriovenous malformations. Gene detection showed a heterozygous mutation, c.277C>T(p.Arg93*), in the ENG gene. Patient 2 was a girl aged 13 years and was admitted due to cyanosis of lips for more than 1 year. The girl had a history of recurrent epistaxis and the manifestations of severe decline in pulmonary diffuse function, pulmonary hypertension, dilation of blood vessels at the distal end of lungs, and small arteriovenous communications in both lungs. Children with HHT often lack typical respiratory symptoms, which may lead to missed diagnosis and misdiagnosis in the early stage. Pulmonary computed tomography or right cardiac acoustic contrast can help with the diagnosis of HHT, and gene detection can improve the early diagnostic rate of this disease.

Extracranial arteriovenous malformations: from bedside to bench

Arteriovenous malformation (AVM) is defined as a fast-flow vascular anomaly that shunts blood from arteries directly to veins. This short circuit of blood flow contributes to progressive expansion of draining veins, resulting in ischaemia, tissue deformation and in some severe cases, congestive heart failure. Various medical interventions have been employed to treat AVM, however, management of which remains a huge challenge because of its high recurrence rate and lethal complications. Thus, understanding the underlying mechanisms of AVM development and progression will help direct discovery and a potential cure. Here, we summarize current findings in the field of extracranial AVMs with the aim to provide insight into their aetiology and molecular influences, in the hope to pave the way for future treatment.

Comprehensive management of hereditary hemorrhagic telangiectasia

PURPOSE OF REVIEW

Hereditary hemorrhagic telangiectasia (HHT), or Osler Weber-Rendu disease, is a rare inherited disorder of fibrovascular tissue affecting various organs. Epistaxis is the most common symptom of HHT but as the disease affects multiple organs, a multisystem and multidisciplinary approach to management is required. The purpose of this article is to provide an overview of the multidisciplinary approach to HHT for the otolaryngologist and to discuss the current pharmacologic and procedural treatment options available for HHT-related epistaxis.

RECENT FINDINGS

Multidisciplinary expert guidelines have better defined what screening tests are advised for the multisystem evaluation of the HHT patient. New pharmacologic therapies including bevacizumab (Avastin) used submucosally or topically have shown promise as in-office treatment modalities. Sclerotherapy of telangiectasia, including in-office applications, has recently proven safe and effective.

SUMMARY

HHT remains a difficult disease to treat. Being aware of the common organ systems involved by the disease will help the practicing otolaryngologist to ensure the patient receives appropriate multidisciplinary care. For HHT-related epistaxis, new medical and surgical options allow for a wider range of treatments than were previously available.

Pazopanib effective for bevacizumab-unresponsive epistaxis in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) most commonly manifests with nasal mucosal telangiectasias, and vascular endothelial growth factor (VEGF) plays a significant role in this angiodysplasia. We describe a patient with HHT with epistaxis recalcitrant to several endonasal procedures and six cycles of intravenous bevacizumab, for which he was dependent on iron infusions and packed red blood cells transfusions. He then started pazopanib at 100 mg with dramatic improvements in epistaxis and normalization of hemoglobin and iron levels, without replenishment needs for 12 months. This is the first report on the efficacy of pazopanib with high selectivity for abrogating VEGF receptor-2 signaling in HHT, and needs to be explored further. Laryngoscope, 128:2234-2236, 2018.

Germline Loss-of-Function Mutations in EPHB4 Cause a Second Form of Capillary Malformation-Arteriovenous Malformation (CM-AVM2) Deregulating RAS-MAPK Signaling

BACKGROUND

Most arteriovenous malformations (AVMs) are localized and occur sporadically. However, they also can be multifocal in autosomal-dominant disorders, such as hereditary hemorrhagic telangiectasia and capillary malformation (CM)-AVM. Previously, we identified RASA1 mutations in 50% of patients with CM-AVM. Herein we studied non-RASA1 patients to further elucidate the pathogenicity of CMs and AVMs.

METHODS

We conducted a genome-wide linkage study on a CM-AVM family. Whole-exome sequencing was also performed on 9 unrelated CM-AVM families. We identified a candidate gene and screened it in a large series of patients. The influence of several missense variants on protein function was also studied in vitro.

RESULTS

We found evidence for linkage in 2 loci. Whole-exome sequencing data unraveled 4 distinct damaging variants in EPHB4 in 5 families that cosegregated with CM-AVM. Overall, screening of EPHB4 detected 47 distinct mutations in 54 index patients: 27 led to a premature stop codon or splice-site alteration, suggesting loss of function. The other 20 are nonsynonymous variants that result in amino acid substitutions. In vitro expression of several mutations confirmed loss of function of EPHB4. The clinical features included multifocal CMs, telangiectasias, and AVMs.

CONCLUSIONS

We found EPHB4 mutations in patients with multifocal CMs associated with AVMs. The phenotype, CM-AVM2, mimics RASA1-related CM-AVM1 and also hereditary hemorrhagic telangiectasia. RASA1-encoded p120RASGAP is a direct effector of EPHB4. Our data highlight the pathogenetic importance of this interaction and indicts EPHB4-RAS-ERK signaling pathway as a major cause for AVMs.