Pulmonary arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia

Pulmonary arteriovenous malformations (PAVMs) associated with hereditary hemorrhagic telangiectasia may cause severe cerebral complications that may be prevented by embolization therapy. We retrospectively compared the diagnostic value of noninvasive tests for the screening of treatable (amenable to embolization) PAVMs in a series of 105 patients, using chest computerized tomography (CT) and/or pulmonary angiography as a "gold standard." Patients had assessment of dyspnea, chest radiograph, alveolar-arterial PO2 gradient under 100% oxygen (AaPO2), contrast echocardiography, and radionuclide perfusion lung scanning. Contrast echocardiography in the supine position was the most sensitive test (93%). The sensitivity of self-reported dyspnea (59%), chest radiograph alone (70%), measurement of AaPO2 by the 100% oxygen method (62%), or radionuclide lung scanning (71%), was not suitable for efficient screening. A 100% sensitivity and negative predictive value could be obtained when combining anteroposterior chest radiograph and contrast echocardiography. Our data support a screening algorithm based on the combined use of contrast echocardiography and anteroposterior chest radiograph, followed by chest CT if either test is positive. An alternative is to screen directly by chest CT. However, this algorithm may obviate the need for chest CT in patients without PAVM, who represent a majority of patients with hereditary hemorrhagic telangiectasia.     

Identical twins with hereditary hemorrhagic telangiectasia concordant for cerebrovascular arteriovenous malformations

Central nervous system arteriovenous malformations are uncommon in hereditary hemorrhagic telangiectasia. Identical twins are described with hereditary hemorrhagic telangiectasia and concordance for central nervous system arteriovenous malformations identified by angiography. One twin had a central nervous system hemorrhage in the seventh month of pregnancy and also had a pulmonary arteriovenous malformation. The other was asymptomatic. A previously reported association between HLA type A2 BW17 and hereditary hemorrhagic telangiectasia was not confirmed. Two recombinations were identified between the loci for HLA and hereditary hemorrhagic telangiectasia. The loci for HLA and hereditary hemorrhagic telangiectasia are not closely linked. Stroke in a young person should prompt an inspection for manifestations of hereditary hemorrhagic telangiectasia.     

Multiple pulmonary arteriovenous malformations associated with hereditary hemorrhagic telangiectasia]

A 61-year old asymptomatic woman was admitted to our hospital for the examination of an abnormal shadow in the left lower lung lobe in 1978. Enhanced chest computed tomograms and pulmonary arteriograms revealed a pulmonary arteriovenous malformation (PAVM) composed of feeding artery and draining vein. The patient had suffered brain abscesses 3 times because of paradoxical emboli from PAVMs. A diagnosis of hereditary hemorrhagic telangiectasia (HHT) was made according to the criteria. The patient died of septic shock due to urinary tract infection by Candida albicans. We reviewed cases of PAVMs associated with HHT in the Japanese literature. In Japan, 126 HHT families and 144 HHT patients have been reported to date. PAVMs occur in approximately one-third of HHT patients in Japan. Twenty-four out of 45 patients (44.4%) had multiple PAVMs. We also discussed the diagnosis, complications, and treatment of PAVM-associated HHT.     

Pulmonary arteriovenous malformations, hereditary hemorrhagic telangiectasia, and brain abscess

Hereditary hemorrhagic telangiectasia (HHT) is a systemic angiodysplasia inherited as an autosomal dominant disease. Patients with HHT and pulmonary arteriovenous malformations (PAVMs) are at increased risk for brain abscess (BA), a potentially preventable condition as effective treatment for PAVMs is available. In a center dedicated to HHT, a history of BA was found in 6 out of 128 patients with a definite diagnosis: herewith, their histories are reported focusing on mistakes in the diagnosis and management of the disease. Patients with PAVMs and BA had a higher mean hemoglobin concentration (15.1 g/dl vs. 12.2 g/dl, p < 0.006 by Student's t test) compared to patients with PAVMs alone. Other clinical features (genetics, bacteriology, types of PAVMs, treatments, outcomes) are also discussed. Prompt diagnosis and screening for visceral involvement is pivotal for HHT patients and their relatives.     

Recurrence of pulmonary arteriovenous malformations in a female with hereditary hemorrhagic telangiectasia

Pulmonary arteriovenous malformations (AVMs) are an uncommon disorder and may cause life-threatening complications if left untreated. The paucity of good longitudinal data on patients with pulmonary AVMs can be a significant challenge clinically. The authors report a case of recurrence of pulmonary AVMs in a young female with hereditary hemorrhagic telangiectasia (HHT) subjected to transcatheter embolotherapy (TCET) in 1995. Recurrence of pulmonary AVMs was suspected because of marked impairment of oxygenation in 1997 and in 2000, while the patient was pregnant, and later confirmed by imaging studies in early 2003. Despite successful embolization of all visible pulmonary AVMs, contrast echocardiography suggested the presence of intrapulmonary shunt. A shunt of 11.4% was measured using a 100% oxygen test. Loss of flow pattern was the immediate change of pulmonary AVMs after TCET shown by chest sonography. A decrease in the size of the pulmonary AVMs was observed 6 weeks later. This case illustrates the clinical relevance of longitudinal monitoring of arterial blood gases in screening for the recurrence of pulmonary AVMs, particularly in patients with HHT, and the roles of chest sonography and contrast echocardiography in monitoring the efficiency of TCET.     

Hepatic vascular malformations in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder that can involve the liver diffusely in the form of vascular malformations ranging from small telangiectases to discrete arteriovenous malformations. Anatomically, three different patterns of abnormal vascular communications can occur in liver: portal vein to hepatic vein (portovenous), hepatic artery to hepatic vein (arteriovenous) and hepatic artery to portal vein (arterioportal), with the most common being arteriovenous. Only 5 to 8% of patients with these vascular malformations are symptomatic. When symptomatic, patients present with high-output cardiac failure, biliary ischemia (which, when severe, can progress to biliary and hepatic necrosis and lead to acute liver failure), or portal hypertension. Other less common presentations include portosystemic encephalopathy and abdominal angina. Diagnosis is confirmed by Doppler ultrasonography or multidetector computed tomography. The hallmark findings are intrahepatic hypervascularization and an enlarged common hepatic artery. Focal nodular hyperplasia and nodular regenerative hyperplasia are common findings. Symptomatic patients are treated with intensive medical treatment aimed at the predominant clinical presentation. Patients who fail aggressive medical therapy and those with acute biliary/hepatic necrosis should be considered for liver transplantation.     

Pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia: a series of 126 patients

Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder characterized by epistaxis, telangiectasia, and visceral vascular manifestations. Infectious and ischemic central nervous system (CNS) manifestations due to embolism through pulmonary arteriovenous malformations (PAVMs) represent the main causes of morbidity. To improve the phenotypic characterization of HHT with PAVM, we conducted a retrospective multicenter study of patients with HHT and at least 1 PAVM detected by chest computed tomography (CT) and/or pulmonary angiography, with particular attention to CNS and infectious manifestations. The study included 126 patients (47 men, 79 women), with a mean age of 43.1 +/- 17.4 years; 45 patients had a mutation of the ENG gene and 16 had a mutation of ACVRL1. PAVMs were diagnosed as a result of systematic screening procedures (29%), incidental imaging findings (15%), dyspnea (22%), or CNS symptoms (13%). The PAVMs were diagnosed at a mean age of 43 +/- 17 years, with a linear distribution of diagnosis between 20 and 75 years. Dyspnea on exertion was present in 56% of patients. Four patients had a hemothorax, including 1 during pregnancy. Fifty-three CNS events directly related to HHT (excluding migraine) were observed in 35% of patients: cerebral abscess (19.0%), ischemic cerebral stroke (9.5%), transient cerebral ischemic attack (6.3%), and cerebral hemorrhage (2.4%). The median age of onset was 33 years for cerebral abscesses (range, 11-66 yr), and 53.5 years for ischemic cerebral events (range, 2-72 yr). Migraine was reported in 16% of patients. The diagnoses of PAVM and HHT were made at the time of the cerebral abscess in 13 cases (54%). Forty-three percent of patients were hypoxemic at rest. Contrast echocardiography showed intrapulmonary right-to-left shunting in 87% of tested patients. PAVMs were seen on chest radiograph in 54% of patients, and on the CT scan in all patients. One hundred five patients (83%) underwent treatment of the PAVM, by percutaneous embolization (71%) and/or by surgical resection (23%). A high frequency of CNS and infectious complications was observed in this large series of patients with HHT-related PAVM. Physicians may not be sufficiently aware of the clinical manifestations of this orphan disorder. Patients diagnosed with HHT should be informed by physicians and patient associations of the risk of PAVM-related complications, and systematic screening for PAVM should be proposed, regardless of a patient's symptoms, familial history, or genetic considerations.     

Pulmonary arteriovenous malformations: screening procedures and pulmonary angiography in patients with hereditary hemorrhagic telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited disease with a high prevalence of pulmonary arteriovenous malformations (PAVMs). The first symptom of HHT may be stroke or fatal hemoptysis associated with the presence of PAVM. OBJECTIVE: To evaluate different screening methods applied for the identification of PAVMs. SETTING: Odense University Hospital. SUBJECTS: HHT patients with positive findings on contrast echocardiography (CE) who participated in a screening investigation and underwent pulmonary angiography (PA). METHODS: Different screening methods were evaluated against the results of PA. In a group of patients with positive findings on CE, we compared results of PA with the following: severity of dyspnea; results of pulse oximetry arterial oxygen saturation (SaO2) supine and upright; supine PaO2 in room air and while breathing 100% oxygen; size of arteriovenous shunt in supine position; chest radiograph; and intensity of contrast at CE. RESULTS: PA was performed in 25 HHT patients with positive findings on CE, 15 of whom had PAVM. Embolization therapy was recommended in 12 patients, and 3 patients had small PAVMs not accessible for therapy. In 10 patients, PAVM could not be demonstrated at PA. The sensitivity and specificity calculated for the screening procedures are as follows: 53% and 90%, respectively, for SaO2; 60% and 100%, respectively, for chest radiograph; 73% and 80%, respectively, for PaO2 in room air; 100% and 40%, respectively, for PaO2 breathing 100% oxygen; and 64% and 80%, respectively, for shunt measurement. CONCLUSION: Initial screening with CE followed by measurement of PaO2 while breathing 100% oxygen seemed to be the best screening procedure for identification of patients with PAVM. Screening with chest radiograph and pulse oximetry was shown to be insufficient.     

Gastric angiodysplasia in a hereditary hemorrhagic telangiectasia type 2 patient

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal-dominantly inherited disease that occurs in approximately one in 5000 to 8000 people. Clinical diagnosis of HHT is made when a person presents three of the following four criteria: family history, recurrent nosebleeds, mucocutaneous telangiectasis, and arteriovenous malformations (AVM) in the brain, lung, liver and gastrointestinal (GI) tract. Although epistaxis is the most common presenting symptom, AVMs affecting the lungs, brain and GI tract provoke a more serious outcome. Heterozygous mutations in endoglin, activin receptor-like kinase 1 (ACVRL1; ALK1), and SMAD4, the genes involved in the transforming growth factor-β family signaling cascade, cause HHT. We report here the case of a 63 year-old male patient who presented melena and GI bleeding episodes, proven to be caused by bleeding from multiple gastric angiodysplasia. Esophagogastroduodenoscopy revealed multiple angiodysplasia throughout the stomach. Endoscopic argon plasma coagulation was performed to control bleeding from a gastric angiodysplasia. The patient has been admitted several times with episodes of hemoptysis and hematochezia. One year ago, the patient was hospitalized due to right-sided weakness, which was caused by left basal ganglia hemorrhage as the part of HHT presentation. In family history, the patient's mother and elder sister had died, due to intracranial hemorrhage, and his eldest son has been suffered from recurrent epistaxis for 20 years. A genetic study revealed a mutation in exon 3 of ALK1 (c.199C > T; p.Arg67Trp) in the proband and his eldest son presenting epistaxis.