Pulmonary vascular manifestations of hereditary hemorrhagic telangiectasia (rendu-osler disease)

Pulmonary arteriovenous malformations in Rendu-Osler-Weber syndrome

Rendu-Osler-Weber syndrome, also known as hereditary hemorrhagic telangiectasia, is an autosomal dominant hereditary disorder. It is characterized by presence of multiple arteriovenous malformations (AVMs) and telangiectasias. This article reports two cases of patients with Rendu-Osler-Weber syndrome who had pulmonary AVMs and underwent successful endovascular treatment. A brief review of the literature shows that up to 50% of patients with the syndrome have pulmonary AVMs and there is usually a positive family history in these patients. These pulmonary AVMs are multiple in 30% of cases and are associated with the most severe disease complications. Most patients are asymptomatic, even in the presence of AVMs with right-left shunts. When these shunts exceed 25% of the total blood volume, dyspnea, cyanosis, digital clubbing, and extracardiac murmurs may occur. Endovascular treatment is safe and offers control of complications from hereditary hemorrhagic telangiectasia and is currently the treatment of choice for these lesions.

Life-threatening hemothorax due to rupture of pulmonary arteriovenous malformation during pregnancy

Pulmonary arteriovenous malformation (PAVM) can worsen in pregnant women due to pregnancy-related physiological changes. If a PAVM ruptures, it can become life-threatening. A 24-year-old female patient at 22 weeks of gestation presented to the hospital with chest pain and dyspnea. A simple chest radiograph revealed that the right lung was almost completely collapsed due to massive pleural effusion, and the heart was displaced to the opposite side. Closed thoracostomy was performed and 2 l of blood was drained. Chest CT revealed the presence of a PAVM in the right upper lung. Emergency surgery was performed to resect the PAVM through thoracoscopic pulmonary wedge resection. The patient experienced disseminated intravascular coagulation and acute renal insufficiency after the surgery, but eventually recovered and was discharged without any complications on the sixth postoperative day.

[Brain abscess as a complication of pulmonary manifestation of HHT]

A 43-year-old female patient with a brain abscess and a complicated clinical course was diagnosed with hereditary haemorrhagic telangiectasia (HHT) at the Martin Zeitz Centre for Rare Diseases in Hamburg, Germany. The brain abscess was caused by pulmonary arteriovenous malformations (AVM), a typical finding in HHT. Patients with cryptogenic brain abscess should be screened for pulmonary AVM and HHT. This case report illustrates the importance of patient history and interdisciplinary exchange in patients with a broad clinical spectrum as well as interdisciplinary treatment in the case of complications of rare diseases.

A missed case of hereditary hemorrhagic telangiectasia: A case report

Hereditary hemorrhagic telangiectasia is a rare autosomal dominant disorder characterized by abnormal blood vessel formation. When an abnormal vascular architecture affects the lungs and central nervous system, serious complications can occur. We report a missed case of hereditary hemorrhagic telangiectasia with pulmonary arteriovenous malformations and cerebral arteriovenous malformations. A 22-year-old Chinese female was taken to the emergency room because of unconsciousness. Emergency head contrast-enhanced computed tomography and transthoracic contrast echocardiography showed that she had cerebral arteriovenous malformations and pulmonary arteriovenous malformations. The patient experienced multiple spontaneous epistaxis since childhood, for which she was treated at a local hospital for a brief period. Her mother also had pulmonary arteriovenous malformations. The patient was diagnosed with hereditary hemorrhagic telangiectasia according to the consensus Curaçao diagnostic criteria and eventually died of hereditary hemorrhagic telangiectasia. The case report highlights the importance of early diagnosis and intervention for hereditary hemorrhagic telangiectasia. Given that hereditary hemorrhagic telangiectasia is frequently undiagnosed, increasing the physician’s awareness of hereditary hemorrhagic telangiectasia can play an important role in the timely diagnosis and treatment of these patients.

[Hereditary hemorrhagic telangiectasia (Rendu-Osler syndrome)]

The analysis of publications is carried out and current data concerning the etiology, pathogenesis, diagnosis, and principles of treatment of hereditary hemorrhagic telangiectasia are presented.

Lung Nodules and Hypoxemia: Any Association?

Pulmonary arteriovenous malformations (PAVMs) consist of aberrant circulation between pulmonary arteries and veins causing right-to-left shunt, uncommon and asymptomatic in the general population. We presented two patients, one presented with unexplained dyspnea and disease limited to the lung and the other with neurologic signs and systematic disease. Both patients were diagnosed with arteriovenous malformations and received embolization treatment successfully. Both patients received embolization treatment successfully.

A case of pulmonary arteriovenous malformation in the setting of Rendu Osler Weber syndrome

Rendu Osler Weber syndrome is a rare disorder, in which arteriovenous malformations are a hallmark feature. We describe the case of a 77-year-old female patient who presented with dyspnea, recurrent epistaxis, and signs of right ventricular heart failure, along with hypoxia and severe anemia. Several imaging modalities facilitated diagnostic workup. The computed tomography revealed an area of pulmonary arteriovenous malformation. Visceral involvement, along with clinical criteria and medical history, established the diagnosis of Rendu Osler Weber syndrome. The patient was scheduled for embolization of the PAVM soon after the diagnosis. Proper imaging, guided by clinical suspicion can be extremely helpful in diagnosing and treating this rare entity.

High output cardiac failure in 3 patients with hereditary hemorrhagic telangiectasia and hepatic vascular malformations, evaluation of treatment

BACKGROUND

This report addresses how patients with hereditary hemorrhagic telangiectasia (HHT) and high output cardiac failure (HOCF) due to hepatic vascular malformations, should be evaluated and could be treated. HHT is a genetic disorder, leading to vascular abnormalities with potentially serious clinical implications. In the liver, arteriovenous malformations occur in more than 70% of patients, but only about 8% present clinical symptoms such as HOCF with pulmonary hypertension and less commonly portal hypertension, biliary ischemia and hepatic encephalopathy.

RESULTS

Three female patients with HHT type 2 and HOCF caused by severe arteriovenous malformations in the liver are presented in this case series. The patients were seen at the HHT-Centre at Odense University Hospital. Treatment with either orthotopic liver transplantation (one patient) or bevacizumab (two patients) was initiated. All patients experienced marked symptom relief and objective improvement. New York Heart Association-class were improved, ascites, peripheral edema and hence diuretic treatment was markedly reduced or discontinued in all three patients. Bevacizumab also resulted in notable effects on epistaxis and anemia.

CONCLUSION

Our findings substantiate the importance of identification of symptomatic arteriovenous malformations in the liver in patients with HHT. Bevacizumab may possibly, as suggested in this case series and supported by previous case studies, postpone the time to orthotopic liver transplantation or even make it unnecessary. Bevacizumab represents a promising new treatment option, which should be investigated further in clinical trials.

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.

Hypoxemia without Respiratory Distress: Hereditary Hemorrhagic Telangiectasia in a Child

Hereditary hemorrhagic telangiectasia (HHT) is an underrecognized genetic disorder of vascular development in pediatric patients. Its presentation can range from mild cutaneous findings to life-threatening hemorrhage from arteriovenous malformations. Clinical diagnosis can be challenging in the pediatric population as disease manifestations evolve over time and may be difficult to identify in younger patients. This case highlights how nonspecific symptoms and signs in the preanesthesia period can be misleading, potentially placing a patient with unrecognized HHT at risk for significant morbidity and mortality.

Transcriptional profiling of lung cell populations in idiopathic pulmonary arterial hypertension

Despite recent improvements in management of idiopathic pulmonary arterial hypertension, mortality remains high. Understanding the alterations in the transcriptome–phenotype of the key lung cells involved could provide insight into the drivers of pathogenesis. In this study, we examined differential gene expression of cell types implicated in idiopathic pulmonary arterial hypertension from lung explants of patients with idiopathic pulmonary arterial hypertension compared to control lungs. After tissue digestion, we analyzed all cells from three idiopathic pulmonary arterial hypertension and six control lungs using droplet-based single cell RNA-sequencing. After dimensional reduction by t-stochastic neighbor embedding, we compared the transcriptomes of endothelial cells, pericyte/smooth muscle cells, fibroblasts, and macrophage clusters, examining differential gene expression and pathways implicated by analysis of Gene Ontology Enrichment. We found that endothelial cells and pericyte/smooth muscle cells had the most differentially expressed gene profile compared to other cell types. Top differentially upregulated genes in endothelial cells included novel genes: ROBO4, APCDD1, NDST1, MMRN2, NOTCH4, and DOCK6, as well as previously reported genes: ENG, ORAI2, TFDP1, KDR, AMOTL2, PDGFB, FGFR1, EDN1, and NOTCH1. Several transcription factors were also found to be upregulated in idiopathic pulmonary arterial hypertension endothelial cells including SOX18, STRA13, LYL1, and ELK, which have known roles in regulating endothelial cell phenotype. In particular, SOX18 was implicated through bioinformatics analyses in regulating the idiopathic pulmonary arterial hypertension endothelial cell transcriptome. Furthermore, idiopathic pulmonary arterial hypertension endothelial cells upregulated expression of FAM60A and HDAC7, potentially affecting epigenetic changes in idiopathic pulmonary arterial hypertension endothelial cells. Pericyte/smooth muscle cells expressed genes implicated in regulation of cellular apoptosis and extracellular matrix organization, and several ligands for genes showing increased expression in endothelial cells. In conclusion, our study represents the first detailed look at the transcriptomic landscape across idiopathic pulmonary arterial hypertension lung cells and provides robust insight into alterations that occur in vivo in idiopathic pulmonary arterial hypertension lungs.

Treatment of pulmonary arteriovenous malformations: clinical experience using different embolization strategies

PURPOSE

To evaluate embolization efficacy of pulmonary arteriovenous malformations (PAVM) using Amplatzer vascular plugs (AVP) and coils.

MATERIALS AND METHODS

Eighty-eight embolized simple PAVMs in 38 patients were retrospectively analyzed by follow-up CT. Mean age was 50.2 ± 15.6 years and 22 (57.9%) patients were females. Mean follow-up interval was 38.2 ± 28.4 months (median 29.9 months). Embolization devices included AVP I, AVP II, AVP 4, and coils. Technical success was defined as no visualization of an early draining vein at angiography after embolization. Treatment success was defined as complete disappearance or decrease in size of the venous aneurysm ≥ 70% at follow-up CT.

RESULTS

Technical success rate was 100% and treatment success rate evaluated by CT for the various embolization strategies was 100% for AVP I (n = 6), 100% for AVP I + coils (n = 5), 83.3% for AVP II (n = 6), 40.0% for AVP II + coils (n = 5), 87.5% for AVP 4 (n = 8), 50.0% for AVP 4 + coils (n = 8), and 78.0% for coils alone (n = 50). No statistically significant difference in embolization efficacy was seen between different devices (P = 0.083). Although not statistically significant, combination use of coils with AVPs demonstrated lower rates of clinical embolization success (P = 0.053).

CONCLUSION

Embolization of PAVMs demonstrated high technical and treatment success rates with available embolic devices. No significant statistical differences were demonstrated between AVPs. However, the need for both coils and AVPs may suggest a more complicated underlying lesion at risk for recurrence.

[Hemoptysis in Pregnancy]

Here we present an extremely rare but important cause of pulmonary hemorrhage during pregnancy. A 41-year-old patient was seen with hemoptysis in the 29th week of her pregnancy which was initially assessed as unspecific inflammation. At the 34th week of pregnancy, she presented again, this time with hemoptoe and dizziness caused by an unknown idiopathic pulmonary AV malformation. The patient underwent extensive interdisciplinary evaluation including bronchoscopy, emergency cesarean section was performed, which was followed by CT scan and VATS/minithoracotomy with segment resection.

Hospitalizations with hereditary hemorrhagic telangiectasia and pulmonary hypertension in the United States from 2000 to 2014

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease that causes widespread abnormal vasculature development, resulting in multiple complications including pulmonary hypertension (PH). Despite the potential severity of PH, there is a lack of data on hospitalization characteristics and outcomes in the HHT-PH population. The purpose of this analysis was to describe trends and outcomes of HHT-PH hospitalizations within the National (Nationwide) Inpatient Sample (NIS).

METHODS

Adult hospitalizations (age ≥18 years) with a principal or secondary diagnosis of HHT were identified from the 2000-2014 NIS. Records were stratified by a concurrent PH diagnosis. Trends, characteristics, and outcomes of hospitalizations with HHT and PH were analyzed.

RESULTS

There were 55,189 adult hospitalizations with HHT from 2000 to 2014, of which 4602 (8.3%) had a concurrent diagnosis of PH. HHT-PH hospitalizations rose steadily from 165 (5.1%) in 2000 to 540 (13.8%) in 2014 (p < 0.001). They were more common in females (vs. HHT without PH, 71.6% vs. 59.2%, p < 0.001) and were associated with a higher comorbidity burden (total 4.0 ± 0.1 vs. 2.4 ± 0.03, p < 0.001). Inpatient mortality was higher in HHT-PH hospitalizations than in HHT without PH (3.5% vs. 1.8%, p < 0.001). On multivariable logistic regression, the diagnosis of PH remained significantly associated with a higher risk of inpatient death (odds ratio 1.71, 95% confidence interval 1.11-2.63, p = 0.015) in HHT hospitalizations.

CONCLUSIONS

HHT-PH hospitalizations rose from 2000 to 2014. Notably, HHT patients with a concurrent PH diagnosis were at significantly higher risk of in-hospital mortality.

Pulmonary arteriovenous malformations

Pulmonary arteriovenous malformation, a condition most commonly associated with hereditary hemorrhagic telangiectasia, is an abnormal communication between the pulmonary artery and pulmonary vein without an intervening capillary communication. Although asymptomatic in ~ 50% individuals, it can present with the dreaded complications of stroke or intracranial abscess in high-risk individuals including pregnant women, if untreated. The mainstay of treatment is now endovascular embolization of the feeding artery which can alleviate the symptoms and prevent these complications. In this review, we describe the pathophysiology, methods of screening, diagnostic workup and treatment of these vascular lesions with a particular focus on the currently used embolization techniques and their outcomes.

A case report of hepatopulmonary syndrome in hereditary hemorrhagic telangiectasia (HHT): Not all right-to-left shunting in HHT is due to pulmonary arteriovenous malformations

RATIONALE

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by abnormal vessel growth that results in telangiectasias and arteriovenous malformations (AVMs) in the skin, mucosa, and viscera. Up to 30% of patients with HHT exhibit pulmonary AVMs (PAVMs), clinically manifesting as right-to-left shunting and hypoxemia.

PATIENT CONCERNS

We report an unusual and novel case of a patient with HHT who lacked clinical sequelae of portal hypertension but presented to clinic with hypoxemia without dyspnea.

DIAGNOSES

Diagnostic workup revealed noncardiac right-to-left shunting due to hepatopulmonary syndrome (HPS) from HHT-induced portal hypertension rather than PAVMs. The diagnosis was confirmed by the absence of PAVMs on chest computed tomography and evidence of elevated portal pressures as noted by the presence of small esophageal varices on upper endoscopy and histologic findings on liver biopsy.

INTERVENTION

Due to the patient's mild symptoms, no further intervention was required. He was closely followed up in the outpatient setting for changes in symptoms and underwent annual screening for development of PAVMs.

OUTCOMES

The patient continues to do well clinically. He has not experienced worsening hypoxemia or dyspnea and has not developed PAVMs.

LESSONS

Given that management of hypoxemia in HPS drastically differs from that of hypoxemia due to PAVMs, this case demonstrates the importance of evaluating HHT patients for HPS if they exhibit impaired oxygenation and noncardiac right-to-leftshunting in the setting of hepatic arteriovenous shunting.

Clinical features and treatment of hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant disorder characterized by vascular dysplasia, including typically systemic telangiectases and arteriovenous malformations (AVMs). Due to its variable clinical manifestations, HHT patients often seek medical care from different medical subspecialties and thus experience delays in diagnosis and treatment.This study is designed to analyze the clinical features and treatment options for patients with HHT.Hospitalized patients with a definitive diagnosis of HHT from November 1973 to July 2016 in Peking Union Medical College Hospital were identified after reviewing medical records and electronic databases. Further follow-up data of these patients were collected from outpatient clinical visits and/or telephone interviews.We identified a total of 20 patients, 7 males and 13 females. The mean age was 42.4 ± 20.3 years. Epistaxis (18/20) was the most common presentation, followed by telangiectases of the oral buccal mucosa, tongue and/or lips (14/20), pulmonary AVMs (12/19), hepatic AVMs (9/17), gastrointestinal telangiectases (9/9), and encephalic AVMs (1/12). The correct diagnosis of HHT was delayed on average by about 26.4 ± 17.0 years from the onset of HHT-related clinical signs and symptoms. Although epistaxis is usually presented in childhood (mean age 11 ± 7.1 years), gastrointestinal telangiectasia was often encountered in late middle age (mean age 55.4 ± 12.8 years). Bleeding and anemia were the most common complications. Molecular analysis was conducted in 4 patients. Only 1 patient was found to have a single-base deletion in ENG gene. The mean duration of follow-up of the patients was 41.8 months. The efficacy of locoregional therapy was of limited value and short-lived. Two patients were treated systemically with thalidomide, and their symptoms of epistaxis, melena, and anemia were notably improved.Patients with HHT have variable clinical characteristics, and their diagnoses were delayed on average by about 26 years. An experienced multidisciplinary team is needed for the early diagnosis and optimal management of patients with HHT. Thalidomide may be an effective choice to alleviate the bleeding symptoms of patients with HHT.

A new ENG mutation in a Japanese family with hereditary hemorrhagic telangiectasia and pulmonary arteriovenous malformations

We present a case series of four siblings with hereditary hemorrhagic telangiectasia (HHT) and pulmonary arteriovenous malformations (PAVM). The patients' mother has HHT. Case 1: A 22-year-old man developed dyspnea and epistaxis. CT revealed a large PAVM, treated by segmentectomy. Case 2: A 27-year-old woman developed epistaxis and dyspnea. CT revealed three PAVMs, treated by partial resection. Case 3: A 20-year-old woman developed dyspnea. CT revealed multiple PAVMs, treated with endovascular occlusion of the largest one. Case 4: A 12-year-old woman developed epistaxis. CT revealed multiple PAVMs, observed without treatment. Genetic testing identified a new mutation, ENG c.1517T>C (p.Leu506Pro), in all patients and their mother. We suspect that HHT in these patients may be associated with this ENG mutation.

Life expectancy and comorbidities in patients with hereditary hemorrhagic telangiectasia

There are only a few published studies that demonstrate associations between life expectancy, severe comorbidities, and their complications in patients with hereditary hemorrhagic telangiectasia (HHT). Relatives of 73 deceased patients with suspected HHT completed a questionnaire about causes of death, and symptoms and comorbidities that the patients had developed. We compared the data for 55 cases where HHT had been clinically confirmed with the general population. Patients suffering from HHT lost, on average, 19 years (SD 11 years) of potential life compared to the general population. Among the deceased HHT patients, 35% (95% CI: 23–48%) died from sepsis, 26% (95% CI: 16–38%) from cardiac failure, 20% (95% CI: 9–28%) from a severe bleeding episode, and 13% (95% CI: 6–24%) from terminal cancer. Congestive heart failure (69%, 95% CI: 56–80%) and pulmonary hypertension (23%, 95% CI: 14–36%) were the main non-fatal comorbidities in patients with HHT. Patients with HHT appear to have a lower life expectancy than the general population. Sepsis and cardiac failure were the main causes of death. Optimized and targeted screening programs for the most frequent comorbidities followed by improved management of infectious complications may increase life expectancy.

Initial experience of a hereditary hemorrhagic telangiectasia center of excellence

Our objectives in reviewing the initial experience of a hereditary hemorrhagic telangiectasia center of excellence (HHT COE) were to better understand the interventions being performed in the comprehensive care of these patients and to present the early data as a reference for other tertiary centers considering starting an HHT COE. We conducted a retrospective review of consecutive patients referred to our newly developed HHT COE for evaluation and treatment between May 2010 and June 2013. Clinical presentation, otolaryngologic treatments, and other operative interventions were analyzed. One hundred forty-four of the 198 patients (73%) evaluated at the HHT COE had definite HHT based on the Curaçao diagnostic criteria, with 20 additional patients possibly having HHT and undergoing further evaluation to confirm the diagnosis. Sixteen of the 31 patients (52%) referred to otolaryngology required intervention in the operating room for epistaxis. Seventy-two of the 164 (44%) patients with definite or possible HHT required other interventions for internal organ arteriovenous malformations (AVMs), with interventional radiology embolization of pulmonary AVMs being the most common procedure. An HHT COE is important in providing comprehensive care for patients with this rare disease, which has significant clinical sequelae. Having an HHT COE allows for early screening and subspecialty referral within a system of specialists experienced in preventing the morbidity and mortality associated with severe epistaxis and internal organ AVMs.

Pulmonary arteriovenous malformations in hereditary haemorrhagic telangiectasia: Correlations between computed tomography findings and cerebral complications

OBJECTIVES

Computed tomography (CT) is the modality of choice to characterise pulmonary arteriovenous malformations (PAVMs) in patients with hereditary haemorrhagic telangiectasia (HHT). Our objective was to determine if CT findings were associated with frequency of brain abscess and ischaemic stroke.

METHODS

This retrospective study included patients with HHT-related PAVMs. CT results, i.e. PAVM presentation (unique, multiple, disseminated or diffuse), the number of PAVMs and the largest feeding artery size, were correlated to prevalence of ischaemic stroke and brain abscess. All CTs were reviewed in consensus by two radiologists.

RESULTS

Of 170 patients, 73 patients had unique (42.9 %), 49 multiple (28.8 %), 36 disseminated (21.2 %) and 12 diffuse (7.1 %) PAVMs. Fifteen patients presented with brain abscess; 26 patients presented with ischaemic stroke. The number of PAVMs was significantly correlated with brain abscess (11.5 vs. 6.2, respectively; p=0.025). The mean diameter of the largest feeding artery was significantly correlated with ischaemic stroke frequency (4.9 vs. 3.2 mm, respectively; p=0.0098).

CONCLUSIONS

The number of PAVMs correlated significantly with risk of brain abscess, and a larger feeding artery significantly with more ischaemic strokes. These findings can lead to a better recognition and management of the PAVMs at risk of cerebral complications.

KEY POINTS

• Chest CT helps clinicians to facilitate appropriate PAVM management strategies. • Pulmonary arteriovenous malformation CT findings are correlated with risk of cerebral complications. • Risk of brain abscess is significantly correlated with number of PAVMs. • Risk of ischaemic stroke is significantly correlated with large feeding artery PAVMs. • Prevalence of observed of brain abscess and ischaemic stroke is 26 %.

First use of Micro Vascular Plugs in Australia: Endovascular treatment of pulmonary arteriovenous malformation

This report describes the first Australian experience with the Micro Vascular Plug System (MVP), as a permanent embolic device for the treatment of pulmonary arteriovenous malformations (PAVMs). MVPs deployed in small vessels between 2 mm and 5 mm are demonstrated to be feasible, safe and effective treatment for PAVMs.

Pulmonary hypertension subtypes associated with hereditary haemorrhagic telangiectasia: Haemodynamic profiles and survival probability

BACKGROUND

Different pulmonary hypertension (PH) mechanisms are associated with hereditary haemorrhagic telangiectasia (HHT).

METHODS AND RESULTS

We conducted a retrospective study of all suspected cases of PH (echocardiographically estimated systolic pulmonary artery pressure [sPAP] ≥ 40 mmHg) in patients with definite HHT recorded in the French National Reference Centre for HHT database. When right heart catheterization (RHC) was performed, PH cases were confirmed and classified among the PH groups according to the European guidelines. Among 2,598 patients in the database, 110 (4.2%) had suspected PH. Forty-seven of these 110 patients had RHC: 38/47 (81%) had a confirmed diagnosis of PH. The majority of these had isolated post-capillary PH (n = 20). We identified for the first time other haemodynamic profiles: pre-capillary pulmonary arterial hypertension (PAH) cases (n = 3) with slightly raised pulmonary vascular resistances (PVR), and combined post- and pre-capillary PH cases (n = 4). Compared to controls, survival probability was lower in patients with PAH.

CONCLUSION

This study revealed the diversity of PH mechanisms in HHT. The description of combined post- and pre-capillary PH with/or without high cardiac output (CO) suggests either a continuum between the pre- and post-capillary haemodynamic profiles or a different course in response to high CO.

The Lung in Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited genetic vascular disorder with an estimated prevalence of 1 in 6,000, characterized by recurrent epistaxis, cutaneous telangiectasia, and arteriovenous malformations (AVMs) that affect many organs including the lungs, gastrointestinal tract, liver, and brain. Its diagnosis is based on the Curaçao criteria, and is considered definite if at least 3 of the 4 following criteria are fulfilled: (1) spontaneous and recurrent epistaxis, (2) telangiectasia, (3) a family history, and (4) pulmonary, liver, cerebral, spinal, or gastrointestinal AVMs. The focus of this review is on delineating how HHT affects the lung.

A case of hereditary hemorrhagic telangiectasia with hepatic encephalopathy due to portal hepatic venous shunt

An 86-year-old male who was able to perform all activities of daily living (ADL) was diagnosed with hereditary hemorrhagic telangiectasia (HHT) at 70 years of age. Following his diagnosis, he had been receiving treatment at our hospital. After the sudden onset of a consciousness disorder, he was admitted to our hospital's emergency department with asterixis, a high serum ammonia level, and hepatic encephalopathy. After angiography, he was diagnosed with hepatic encephalopathy due to portal hepatic venous shunts. HHT is characterized by abnormal blood vessel construction and the formation of peripheral vasodilatation and shunt blood vessels. Although rare, portal hepatic venous shunts may sometimes cause hepatic encephalopathy. The extent of this shunt increases with age. As Japan is an increasingly aging society, the number of HHT patients with hepatic encephalopathy is likely to increase markedly in the future.

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.

Birt-Hogg-Dube syndrome accompanied by pulmonary arteriovenous malformation

A 25-year-old male with Birt-Hogg-Dube (BHD) syndrome who developed hemothorax caused by ruptured of pulmonary arteriovenous malformation was reported. The patient was admitted to the hospital due to chest pain. A chest X-ray showed pleural fluid in his left lung, and a chest CT showed the presence of a tumor with enhanced contrast in the lower left lobe of approximately 5 cm in a diameter. Pleural fluid was collected by tap and indicated the presence of blood; therefore, hemothorax was suspected. Thoracoscopic surgery was performed to remove the mass for homostasis. Pathological findings indicated that the resected tumor-like lesion was an intrapulmonary hematoma, and aggregated vascular vessels of various diameters forming incomplete media elastic lamina was observed around the hematoma; therefore, it was diagnosed as pulmonary arteriovenous malformation. Family history of the patient indicated the presence of pneumothorax and malignant diseases, and the patient presented with papules and multiple pulmonary cysts. The genetic test revealed a deletion of exon 11 of the BHD gene; therefore, the patient was diagnosed with BHD syndrome. This report is the first to describe BHD syndrome accompanied by pulmonary arteriovenous malformation.

Pulmonary Hypertension in Hereditary Hemorrhagic Telangiectasia

BACKGROUND

A subset of patients with hereditary hemorrhagic telangiectasia (HHT) develops pulmonary hypertension (PH) by mechanisms including pulmonary arterial hypertension, high flow, and elevated pulmonary arterial wedge pressure (PAWP). We aimed to describe echocardiographic and hemodynamic characteristics of patients with coexisting HHT and PH.

METHODS

We conducted a single-center cohort study of patients with confirmed HHT who underwent right-sided heart catheterization (RHC) and transthoracic two-dimensional echocardiography for suspected PH between June 1, 2003 and September 1, 2013 at Mayo Clinic Rochester, Minnesota.

RESULTS

Of 38 patients with confirmed HHT who underwent RHC and echocardiography, 28 (74%) had a mean pulmonary artery pressure (MPAP) ≥ 25 mm Hg. Of those 28, 12 (43%) had pulmonary arterial hypertension. Two patients had normal PAWP and pulmonary vascular resistance (PVR), with PH secondary to either an atrial septal defect or high cardiac flow. Fourteen patients (50%) had elevated PAWP (≥ 15 mm Hg), nine with evidence of high flow. RHC in all 28 patients demonstrated a MPAP of 41 ± 11 mm Hg, PAWP of 17 ± 10 mm Hg, and PVR of 4.5 ± 4.2 Wood units. Echocardiography demonstrated moderate/severe right ventricular dysfunction in nine patients (32%). The presence of PH trended toward worse survival (P = .06).

CONCLUSIONS

PH in patients with HHT occurs by different mechanisms, and there is a trend toward worse survival in patients who develop PH despite the mechanism. The equal predilection toward all subtypes of PH illustrates the necessity of RHC to clarify the hemodynamics.

Pulmonary vascular complications of hereditary haemorrhagic telangiectasia

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.

Case Report: Brown Fat Accumulation of Tc-99m Macroaggregated Albumin in a Lung Perfusion Study in a Patient With Multiple Lung Arteriovenous Malformations and Right-to-Left Shunting

An 18-year-old man was preoperatively assessed for a varicocele and found to be hypoxemic. A Tc-99m macroaggregated albumin lung perfusion scan showed right-to-left shunting, evidenced by increased radiotracer uptake in the brain, kidneys, thyroid gland, and bilateral supraclavicular areas, a typical location for brown adipose tissue. Chest computerized tomography angiogram study showed supraclavicular fat density areas and multiple pulmonary arteriovenous malformations.The authors report a rare case of brown fat visualization on a lung perfusion scan in a patient with right-to-left shunting, likely because of increased perfusion to activated brown adipose tissue.

Management of a solitary pulmonary arteriovenous malformation by video-assisted thoracoscopic surgery and anatomic lingula resection: video and review

BACKGROUND

Pulmonary arteriovenous malformations are abnormal communications between the pulmonary arterial and venous vasculature leading to a right-to-left blood shunt. Based on possible complications, including hypoxemia, hemorrhage, infection and paradoxical embolism, deactivation of the malformation from the circulation is the treatment option of choice, either by interventional embolization or by surgery. Embolization is less invasive and has widely replaced surgery, but bears the risk of revascularization, recanalization and downstream migration of the device with paradoxical embolism.

METHODS

We report on the case of a 76-year-old male patient suffering from a complex, plexiform pulmonary arteriovenous malformation in the lingula, which was treated by video-assisted thoracoscopic surgery and anatomic lingula resection. Patient's medical history, clinical examination and imaging studies did not reveal any evidence of hereditary hemorrhagic telangiectasia.

RESULTS

Left-sided anterior three-port video-assisted thoracoscopic surgery (VATS) approach was used. Instead of only wedge resecting the very peripherally located pulmonary arteriovenous malformation, the lingular vessels were controlled centrally and an anatomic lingula resection was performed in order to prevent a more central re-malformation. To prevent rupture of the aneurysm sac through pressure overload, the feeding arteries were controlled before the draining vein. Duration of the total procedure was 151 min, the single chest tube was removed on the postoperative day 3, and the patient was discharged on the postoperative day 6.

CONCLUSION

Although interventional embolism of the feeding artery of a pulmonary arteriovenous malformation is the current therapeutic gold standard, minimally invasive anatomic lung resection by video-assisted thoracoscopic surgery can be considered, especially for the treatment of solitary large arteriovenous malformations. By anatomic lung resection, the risk of recanalization, collateralization and peri-interventional paradoxical embolism may be reduced.

Complications and mortality in hereditary hemorrhagic telangiectasia: A population-based study

OBJECTIVES

Studies report that the risks of significant neurologic complications (including stroke, cerebral abscess, and migraine) and hemorrhagic sequelae are high in patients with hereditary hemorrhagic telangiectasia (HHT), and that life expectancy in this cohort is reduced. However, most published cohorts derive from specialist centers, which may be susceptible to bias.

METHODS

We used a population-based approach to estimate the risks of developing neurologic and hemorrhagic complications of HHT, the association of a diagnosis of HHT with common cardiovascular and malignant comorbidities, and also long-term survival of those with the disease.

RESULTS

From a UK primary care database of 3.5 million patients (The Health Improvement Network), we identified 675 cases with a diagnosis of HHT and compared them with 6,696 controls matched by age, sex, and primary care practice. Risks of stroke (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.2-2.6), cerebral abscess (OR 30.0, CI 3.1-288), and migraine (OR 1.7, CI 1.3-2.2) were elevated over controls. Bleeding complications including epistaxis (OR 11.6, CI 9.1-14.7) and gastrointestinal hemorrhage (OR 6.1, CI 2.8-13.4) were more common in cases with HHT. Survival of cases with HHT was poorer than controls with a hazard ratio for death of 2.0 (CI 1.6-2.6) and a median age at death 3 years younger.

CONCLUSIONS

Patients with HHT are at substantially increased risk of serious neurologic and hemorrhagic complications of the disease. Because a diagnosis of HHT is associated with a significantly poorer survival compared with those who have no disease, evaluation of new strategies to improve clinical management is required.

Pulmonary vascular diseases

Pulmonary vascular diseases encompass a large and diverse group of underlying pathologies ranging from venous thromboembolism to congenital malformations to inflammatory vasculitides. As a result, patients can present either acutely with dyspnea and chest pain or chronically with dyspnea on exertion, hypoxia, and right heart failure. Imaging, particularly with multidetector CT, plays a key role in the evaluation and management of patients with suspected pulmonary vascular disease and, given the widespread routine use of high-quality CT pulmonary angiography, it is imperative that radiologists be familiar these pathologies.

Rendu-Osler-Weber Syndrome: A Case Report

Hereditary hemorrhagic telangectasia (HHT) or Rendu-Osler-Weber syndrome, is a rare genetic disorder with autosomal dominance and variable penetrance. The typical findings of the disease are telangiectasias in skin and mucous membranes, and arteriovenous malformations presenting in the organs like lung, intestine, brain and liver. It is characterized by the classic triad of recurrent epistaxis, mucocutaneous telangiectasias and visceral hemorrhages, with familial occurrence. This article describes a case of HHT of an adult patient, associated with multiple angiodysplasic injuries in the nasal mucosa, upper gastrointestinal tract, lungs and who presents continuous blood loss, resulting iron deficiency anemia. Based on clinical and diagnostic findings, we diagnosed this case as HHT, which has rarely been reported in our literature.

Risk factors for recurrent spontaneous epistaxis

OBJECTIVE

To identify risk factors associated with spontaneous recurrent epistaxis.

PATIENTS AND METHODS

This was a retrospective cohort study assessing patients in the Marshfield Clinic system diagnosed as having epistaxis between January 1, 1991, and January 1, 2011. There were 461 cases with at least 2 episodes of spontaneous epistaxis within 3 years and 912 controls with only 1 episode in the same time frame. More than 50 potential risk factors were investigated, including demographic features, substance use, nasal anatomical abnormalities, nasal infectious and inflammatory processes, medical comorbidities, medications, and laboratory values. A Cox proportional hazards regression modeling approach was used to calculate hazard ratios of epistaxis recurrence.

RESULTS

Traditional risk factors for epistaxis, including nasal perforation, nasal septum deviation, rhinitis, sinusitis, and upper respiratory tract infection, did not increase the risk of recurrence. Significant risk factors for recurrent epistaxis included congestive heart failure, diabetes mellitus, hypertension, and a history of anemia. Warfarin use increased the risk of recurrence, independent of international normalized ratio. Aspirin and clopidogrel were not found to increase the risk of recurrence. Few major adverse cardiovascular events were observed within 30 days of the first epistaxis event.

CONCLUSION

Congestive heart failure is an underappreciated risk factor for recurrent epistaxis. Hypertension and diabetes mellitus may induce atherosclerotic changes in the nasal vessels, making them friable and more at risk for bleeding. Patients with recurrent epistaxis may also be more susceptible to developing anemia. Physicians should promote antiplatelet and antithrombotic medication adherence despite an increased propensity for recurrent epistaxis to prevent major adverse cardiovascular events.

Multiple embolizations of pulmonary arteriovenous malformations during pregnancy

Pulmonary arteriovenous malformations in a pregnant patient are rare and can cause deleterious, life-threatening complications. We report a patient with multiple pulmonary arteriovenous malformations, with the subsequent diagnosis of hereditary hemorrhagic telangiectasia, requiring multiple embolizations during pregnancy. Pulmonary arteriovenous malformations can carry a high risk of morbidity in the pregnant woman; however, they can be safely treated in pregnancy.