Home Print this page Email this page Small font sizeDefault font sizeIncrease font size
Users Online: 17

 

Home  | About Us | Editors | Search | Ahead Of Print | Current Issue | Archives | Submit Article | Instructions | Subscribe | Contacts | Login 
     


 
 
Table of Contents
REVIEW ARTICLE
Year : 2021  |  Volume : 11  |  Issue : 3  |  Page : 167-176

Pathogenesis and therapy of arteriovenous malformations: A case report and narrative review


1 Lewis Katz School of Medicine, Temple University, Philadelphia, USA
2 Department of Pulmonary and Critical Care, St. Luke's University Health Network, Bethlehem, PA, USA
3 Department of Pathology, St. Luke's University Health Network, Bethlehem, PA, USA
4 Department of Cardiology, St. Luke's University Health Network, Bethlehem, PA, USA

Date of Submission22-Jul-2020
Date of Decision24-Oct-2020
Date of Acceptance05-Jan-2021
Date of Web Publication25-Sep-2021

Correspondence Address:
Dr. Sudip Nanda
Department of Cardiology, St. Luke's University Health Network, Bethlehem, Pennsylvania
USA
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/IJCIIS.IJCIIS_127_20

Rights and Permissions
   Abstract 


Arteriovenous malformations (AVMs) are abnormal communications between arteries and veins that lack intervening capillary beds. They have been described in almost every organ in the body, emerging sporadically or as part of well-described syndromes. Hereditary hemorrhagic telangiectasia (HHT) is a rare, progressive, and lifelong disease characterized by AVMs and recurrent hemorrhaging. In the last 2 decades, significant advances have been made in understanding the pathogenesis of this condition. The accumulation of knowledge has led to a natural evolution of therapy, from open surgery to endovascular procedures, and now to a role for medications in certain AVMs. Here, we review a case of HHT and describe the most up-to-date clinical practice, including diagnosis of HHT, subtypes of HHT, and medical therapy.

Keywords: Arteriovenous malformation, case report, hereditary hemorrhagic telangiectasia, transforming growth factor-β signaling


How to cite this article:
Tessier S, Lipton BA, Ido F, Longo S, Nanda S. Pathogenesis and therapy of arteriovenous malformations: A case report and narrative review. Int J Crit Illn Inj Sci 2021;11:167-76

How to cite this URL:
Tessier S, Lipton BA, Ido F, Longo S, Nanda S. Pathogenesis and therapy of arteriovenous malformations: A case report and narrative review. Int J Crit Illn Inj Sci [serial online] 2021 [cited 2021 Dec 5];11:167-76. Available from: https://www.ijciis.org/text.asp?2021/11/3/167/326594




   Introduction Top


Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant disorder. It is named for progressive lifelong recurrent hemorrhages associated with and due to large and small vascular malformations. Respectively, these are arteriovenous malformations (AVM) and telangiectasias (TeLs). AVM formation can be congenital or acquired. Definitive diagnosis requires at least three of the four widely used International Curacao criteria: (1) epistaxis, (2) mucocutaneous TeLs, (3) AVMs, and (4) family history.[1] The patient described in this case study has all four.


   Case Report Top


A 75-year-old male without known coronary artery disease presented to the emergency department with acute-onset chest pain. His medical history was significant for recurrent epistaxis. Physical examination was normal except for superficial lip TeLs [Figure 1]a. Vital signs included a heart rate of 67 beats/min, blood pressure of 159/80 mmHg, respiratory rate of 18 breaths/min, and oxygen saturation of 87% when breathing ambient air. The complete blood count revealed erythrocytosis with a hemoglobin of 16.9 g/dL and hematocrit of 50.4. Electrocardiogram demonstrated nonspecific ST segment changes in the inferior leads and serial cardiac troponin peaked at 40 ng/ml. Immediate medical therapy included aspirin 325 mg in combination with ticagrelor 180 mg, intravenous heparin infusion, atorvastatin 80 mg, and metoprolol 12.5 mg. Coronary angiography revealed significant multivessel disease. Echocardiogram showed a left ventricular ejection fraction of 50% without evidence of pulmonary hypertension (PH); however, inferolateral hypokinesis and moderate ventricular hypertrophy were noted. A nonemergent coronary artery bypass graft (CABG) was recommended and preoperative testing was performed.
Figure 1: (a) Lip telangiectasias (arrows). (b) Left upper lobe arteriovenous malformation (arrow). (c) Left upper and right lower lobe arteriovenous malformations (arrows). (d) Three-dimensional reconstruction with arteriovenous malfomation isolation. (e) Right occipital lobe infarct. (f) Posterior cerebral artery narrowing of P2 and P3 segments

Click here to view


In preparation for CABG, bilateral carotid ultrasound did not indicate significant atherosclerotic disease. A chest X-ray showed several nondiagnostic pulmonary nodular densities which were identified by a contrast-enhanced chest computed tomography (CT) as pulmonary AVMs (PAVMs). Three-dimensional reconstruction provided detailed configuration and distribution of the PAVMs [Figure 1]b, [Figure 1]c, [Figure 1]d. The patient recalled hemoptysis and hemorrhagic strokes involving both his father and brother. Pulmonary function test revealed normal spirometry and lung volumes and a reduced carbon monoxide diffusion capacity. The periodic hypoxia captured on pulse oximetry was verified with arterial blood gas analysis, which demonstrated a pH of 7.44, pCO2 of 30 mmHg, pO2 of 54 mmHg, and O2 saturation of 89%. The calculated alveolar–arterial gradient (A-a gradient) was elevated at 58 mmHg. Causes of increased A-a gradients include ventilation/perfusion mismatch (i.e., chronic obstructive pulmonary disease [COPD] and pulmonary embolism), diffusion limitations (i.e., pulmonary fibrosis and interstitial lung disease), and both physiologic and anatomic shunts such as atelectasis or pulmonary edema and intracardiac or pulmonary vascular shunts, respectively. Despite supplemental oxygen, the hypoxemia failed to improve, highlighting a unique feature of the right-to-left shunt that accompanies PAVMs. Immediate intervention of the PAVMs was postponed and CABG prioritized. Brain magnetic resonance imaging (MRI) to screen for additional AVMs was negative; however, several bilateral chronic lacunar infarctions were detected in the cerebellum.

Postoperatively, aspirin 325 mg daily, atorvastatin 40 mg daily, and cardiopulmonary rehabilitation were initiated; however, beta-blocker and ACE inhibitor were postponed due to the development of sinus bradycardia and acute kidney injury. New-onset atrial fibrillation with tachycardia occurred on postoperative day 3 and therefore apixaban 5 mg twice daily and metoprolol tartrate 12.5 mg twice daily were commenced. Following his discharge, physical rehabilitation and outpatient cardiology evaluation were maintained.

Three weeks following discharge, he returned to the emergency department with symptoms of blurry vision and an unsteady gate. Vital signs were normal and electrocardiogram demonstrated normal sinus rhythm. A noncontrast CT and contrast-enhanced MRI of the brain revealed an evolving subacute stroke with microhemorrhages in the right occipital lobe [Figure 1]e. Multiple imaging studies for an embolic source included carotid magnetic resonance angiography (MRA), repeat echocardiogram, and lower extremity venous duplex which were negative. MRA of the brain to assess for an aneurysm or clot amenable to endovascular intervention was negative; however, multifocal segmental narrowing of the right posterior cerebral artery was present [Figure 1]f. The symptoms subsided, and following discharge, evaluation by interventional radiology recommended PAVM embolization and genetic testing to allow accurate testing of family members. The patient was also referred to gastroenterology to undergo screening for possible abdominal–visceral AVMs.


   Methods Top


A literature search restricted to the English language was conducted using PubMed to identify articles related to HHT. The search included the MeSH: “Arteriovenous Malformations” and “Telangiectasia, Hereditary Hemorrhagic,” and non-MeSH terms “molecular,” “brain,” “cerebral,” “intracranial,” “pulmonary,” “lung,” “hepatic,” “liver,” “gastrointestinal,” “therapy,” “treatment,” and “prevalence”. The articles were assessed for relevance (pathogenesis and clinical therapy), with particular attention paid to recent findings, the molecular basis of AVM formation, and organ-specific AVM involvement. Furthermore, ClinicalTrials.gov was searched for clinical trials investigating medical approaches to AVMs [Table 1]. Appraisal of the literature and extraction of information was performed by two independent reviewers. Screening of the titles and abstracts was performed first, followed by a critical examination of each article and its findings. The final count of articles used was 89: 38 human experimental studies, 21 basic science/animal studies, 10 case reports/series, 10 reviews, 6 epidemiological studies, and 4 guideline studies. The Critical Appraisal Skills Programme (CASP) checklist was used to ascertain study quality and mitigate risk of bias (https://casp-uk.net/casp-tools-checklists/). The checklists contain criteria on items such as selection bias, measurement or classification bias, confounding factors, validity, precision, and population. The reviewers appraised the studies by assigning the items as positive (if an item was present), negative (if an item was absent), or can't tell/not applicable. The number of items rated positively was divided by the number of applicable items to yield a “CASP score” as a percentage. High-scoring studies represent lower risk of bias, whereas low-scoring studies represent higher risk of bias. CASP scores are shown for the medical therapy studies summarized in [Table 1].
Table 1: Available and future therapies

Click here to view



   Discussion Top


Case report: A clinical challenge

The strength in the approach to the case was the ability to solidify the diagnosis clinically by obtaining a detailed history encompassing symptoms, family history, recognition of physical examination findings (lip TeLs), laboratory values that coincided with PAVMs (erythrocytosis, likely due to chronic hypoxia and the elevated A-a gradient refractory to supplemental oxygen), as well as obtaining the CT of the chest following recognition of nodular densities on chest X-ray. The limitations to our approach were twofold: diagnostic and therapeutic. Diagnostically, we did not have genetic confirmation (although the patient met all clinical criteria). More importantly, we did not have the opportunity to screen for additional AVMs (hepatic, gastrointestinal) before CABG. Although no bleeding complications occurred, the need for antiplatelet therapy following CABG and anticoagulation for atrial fibrillation placed the patient at high risk for bleeding. A catastrophe may have unfolded if he had developed a gastrointestinal bleed from an AVM when on anticoagulation. The second diagnostic limitation was the inability to definitively determine the cause of the stroke. In the setting of large PAVMs, the obvious concern was a paradoxical embolism. However, the etiology was not determined and presumed to be related to atrial fibrillation, although the patient reported compliance with anticoagulation and the MRA of the brain showed stenosis of the vasculature supplying the area of infarction. The final limitation was the therapeutic approach. Closure of the PAVMs was considered a major procedure and would have delayed CABG significantly. The other therapeutic limitation was the choices of therapy following the cerebral infarct. The patient had confirmed atrial fibrillation with a history of chronic cerebellar stroke necessitating anticoagulation; however, he had areas of microhemorrhage and therefore the bleeding risk versus benefit in continuing anticoagulation was challenging.

Hereditary hemorrhagic telangiectasia subtypes

The global prevalence of HHT is 1 in 5,000–10,000,[35] with a higher estimate in Europe and Japan (1 in 5000–8000).[36],[37] Interestingly, the highest rate of 1 in about 1300 occurs within the populace of the Netherlands Antilles islands of Bonaire and Curacao.[38] HHT is characterized by several subtypes with varying phenotypic manifestations that reflect specific genetic mutations. To date, loss-of-function mutations in the transforming growth factor-β (TGF-β)/bone morphogenic protein (BMP) signaling pathway are the only known causes of HHT. The various clinical phenotypes of HHT are the result of dysregulations of four well-recognized genes within the TGF-β/BMP pathway. They include ENG, (endoglin); ACVRL1 (activin A receptor type II-like kinase1 or ALK1), MADH4 (SMAD4), and GDF2 (Growth Differentiation Factor 2, aka BMP9). A given HHT subtype presents variable expressivity, even among the members of the same afflicted family, indicating notable inter- and intrafamilial variability of disease expression. Notably, nearly all of patients with HHT experience recurrent epistaxis at some point in their lives. [Table 2] shows significant clinical highlights of each subtype.
Table 2: Hereditary hemorrhagic telangiectasia subtypes

Click here to view


Molecular basis of arteriovenous malformation formation

AVMs result from an abnormality of angiogenesis. The basic pathways involved are illustrated in [Figure 2].
Figure 2: Schematic illustrating the role of TGF-β signaling in HHT. The proteins affected by mutations that cause HHT are bolded. (A) BMP9 binds to its receptor (i.e. ALK1) on the surface of an endothelial cell. ENG functions as a co-receptor. Induction of SMAD4 promotes anti-angiogenic gene regulation. (B) PI3K/AKT-mediated VEGF signaling drives endothelial cell proliferation and angiogenesis. ALK1-dependent signaling inhibits PI3K, thus contributing to the balance of anti- and pro-angiogenic intracellular states. (C) ANGPT2 functions as an agonist when its concentrations are greater than ANGPT1, and as an antagonist when its concentrations are less than ANGPT1. (D) ENG plays a role in integrin-mediated adhesion between vascular endothelial and mural cells to promote vessel stabilization

Click here to view


The dynamics of blood vessel remodeling are influenced by the antiangiogenic activities of ALK1 and endoglin. ALK1 is a BMP9 and BMP10 receptor that signals through mothers against decapentaplegic homolog-1, -5, and -8 (SMAD1/5/8). SMAD1/5/8 in turn complex with and activate the transcription factor SMAD4. In the nucleus, SMAD4 interacts with transcriptional modulators to promote antiangiogenic gene regulation, including inhibition of angiopoietin-2 (ANGPT2) transcription [Figure 2]a.[28],[46] ALK1 signaling also downregulates angiogenesis by inhibiting PI3K/AKT/mTOR, a common downstream pathway of vascular endothelial growth factor (VEGF) signaling [Figure 2]b. Experimentally, this was well demonstrated by Ola et al., who showed that ALK1 deletion in mice disinhibits PI3K/AKT, resulting in hyperproliferation of endothelial cells and AVM formation. The authors further showed that pharmacological inhibition of P13K rescues these abnormalities.[21] The PI3K/AKT pathway can also be induced by binding of ANGPT2 to its receptor, TIE2. This induction mechanism is context dependent: ANGPT2 functions as an agonist when its concentrations are in excess over its partner TIE2-agonsit, ANGPT1, and as an antagonist when its concentrations are less than ANGPT1 [Figure 2]c. Similar to Ola et al., recent investigations revealed that inhibition of ANGPT2 mitigates AVM formation and improves blood vessel diameter in SMAD4 knockout mice.[28]

Endoglin is an accessory coreceptor for ALK1. Therefore, ALK1 and endoglin jointly inhibit angiogenesis [Figure 2]a.[47] Interestingly, endoglin also plays a role in regulating the stabilization and permeability of the endothelial barrier; in addition to its function as a coreceptor, its RDG motif serves as a ligand for the β1-integrins of pericytes and smooth muscle cells [Figure 2]d.[48] With these mechanisms in mind, one can appreciate how mutations in the genes encoding BMP9, ALK1, endoglin, and SMAD4 lead to formation of AVMs characteristic of HHT.

An engrossing aspect of HHT vascular lesions is that they occur with certain “tropism” for specific organ systems, mucosa, and dermal surfaces, as opposed to manifesting in a diffuse nature. Efforts to explain this phenomenon have put forth the “two-hit” hypothesis. The two-hit hypothesis emerged from observations that a given challenge or assault, such as vascular injury, prompts endothelial cells to upregulate expression of survival factors including endoglin.[49] The hypothesis suggests that mutations in such survival genes (Hit #1) decrease the threshold for endothelial cell survival when stressed by external factors (Hit #2). Evidence for this hypothesis is provided by several studies. For example, mice with a deficiency in endoglin (Hit #1) develop AVMs when exposed to the angiogenic factors VEGF and basic fibroblast growth factor (Hit #2).[50] Likewise, while mice with a deficiency in ALK1 (Hit #1) exhibit pulmonary and gastrointestinal hemorrhaging, an inductive factor such as wounding (Hit #2) is required to initiate the formation of dermal AVMs.[51] Topically applied VEGF-blockade (inhibition of Hit #2) can prevent dermal AVM formation in a wounding mouse model of HHT.[52]

Pulmonary arteriovenous malformations

More than 70% of PAVMs are ascribed to HHT and about 50% of HHT patients are affected by PAVMs.[53],[54] PAVMs serve as anatomical right-to-left shunts, bypassing the alveolar–capillary interface and resulting in hypoxemia. PAVMs increase the risk of paradoxical emboli, which can result in stroke, visceral infarction, and acute limb ischemia.[53],[55] Paradoxical embolisms originate from a dislodged venous thrombus that travels through a right-to-left shunt to the systemic circulation. Such shunts can be intracardiac (i.e., patent foramen ovale or atrial/ventricular septal defects), or extracardiac (i.e., PAVM), as most often is the case in HHT. PAVMs may also be asymptomatic, but still increase risk of potentially life-threatening yet preventable complications.[55]

Anatomically, PAVMs are malformations that allow direct communication between the pulmonary and systemic circulations in the absence of normal capillary connections. They most commonly consist of a supplying artery, a draining vein, and a set of irregularly arranged anomalous vessels, collectively called a nidus. The nidus serves as a high-flow conduit connecting the supplying artery and draining vein, thus circumventing conventional capillary beds. This type of PAVM, in which a single segmental pulmonary artery is involved, is subclassified as “simple.” A “complex” PAVM is noted when two or more pulmonary artery branches are involved.[56] These are important considerations for planning endovascular intervention, especially since transcatheter embolotherapy is widely accepted as the benchmark treatment for this condition.[55] When treatment via embolization is unsuccessful or not possible, lobectomy may be considered as a second option. It may also be the preferred modality when patients are symptomatic, have a more complicated case of PAVM, or when PAVM diagnosis is not possible.[57]

Neurovascular complications

Neurovascular complications are frequently encountered by patients with HHT. In general, these can be characterized as being primary conditions, in which case spinal or cerebral AVMs (CAVMs) are present, or secondary events such as paradoxical emboli, enabled by right-to-left shunting.

An estimated 10%–20% of HHT patients suffer from CAVMs.[58],[59] CAVMs are classified into three subtypes on account of radiologic and angiographic studies. These include (1) small, nonshunting “capillary vascular malformations;” (2) the classic, shunting “nidus-type,” where pial vessels are typically the feeding arteries; and (3) high-volume, single-hole “fistulous” AVMs which lack nidi, also called arteriovenous fistulas (AVFs).[60] About more than 60% of nidus-type CAVMs are discovered incidentally, reflecting their tendency to be asymptomatic, although about 15% of patients with HHT and CAVMs suffer intracranial hemorrhage.[61] While AVFs are the least common CAVM, they are prone to poor angioarchitecture that may complicate patient history. These may include associated aneurysms of engorged feeding arteries, moyamoya-type alterations, arteriostenosis, and venous dilation. Therefore, symptoms of AVFs include those associated with increased intracranial pressure, headache, bruit, hemorrhage, and seizures, as well as congestive cardiac manifestations and altered mental state.[62],[63],[64] Of note, spinal cord AVMs, predominantly occurring in the pediatric HHT population with a prevalence of roughly 1%, may present alongside complaints of back pain and/or paralysis.[65],[66]

Secondary conditions resulting from cerebral embolic complications in patients with HHT include cerebral abscesses and ischemic stroke. Although exceedingly rare in the general population (<1 in 100,000 people per year), they are common in individuals with HHT and PAVMs, since cerebral abscesses are frequently secondary to septic emboli facilitated by intrapulmonary shunt.[62],[67] Accordingly, prophylactic treatment measures are recommended for cerebral abscesses, such as antibiotic administration before invasive procedures and coil embolization of PAVMs.[67]

Ischemic stroke occurs more frequently in HHT patients with PAVMs. Stroke may also result from hyperviscosity due to secondary erythrocytosis caused by chronic right-to-left shunt hypoxemia or gas emboli secondary to communication between airway and pulmonary circulation. Stroke rates in these patients can be markedly reduced by obliteration of PAVMs.[68]

Hepatic involvement

Involvement of the liver in HHT patients is most commonly associated with HHT2.[69] In large prospective studies, the prevalence of hepatic involvement in HHT patients has ranged from 41%[70] to 78%.[71] Clinical presentation varies as most cases involve TeL which are largely asymptomatic. However, due to the dual blood supply of the liver, large shunts can form in one of three types that may coexist: (1) “arteriovenous,” the most common, (2) “arterioportal,” and (3) “portovenous.”[72] In a multidetector row helical CT multiphasic study of 78 HHT patients with hepatic involvement, it was found that arterioportal shunts occurred in 50% of cases, arteriosystemic shunts in 20% of cases, and both shunt types in about 30% of cases.[71] Buscarini et al. determined that morbidity and mortality is increased considerably by these hepatic shunts; out of 154 patients, 25.3% experienced complications from hepatic AVMs (HAVMs) and 5.2% died from AVM-related complications.[73] In a study analyzing the clinical findings of 19 HHT patients with HAVMs, typical clinical presentations included high cardiac output failure, portal hypertension, and biliary disease.[74] Hepatic artery dilation, elevated hepatic artery flow, and intrahepatic hypervascularity are also associated with HAVMs.[75]

HAVMs can be graded using doppler ultrasonography into the categories of minimal (hepatic artery measures >6 mm and is dilated in extrahepatic tract), moderate (hepatic artery is dilated in both intra and extrahepatic tract), or severe (arterial hepatic branches are associated with hepatic and/or portal vein dilation).[70] In a cohort of 92 patients with HHT and hepatic involvement, 12% of HAVMs were minimal, 76% were moderate, and 12% were severe.[70] Aside from ultrasonography, HAVMs can be detected using MRI, triphasic spiral CT, and mesenteric angiography.[76]

PH is an increasingly recognized complication of HHT and is frequently described in HHT2.[77] PH most often presents as postcapillary hypertension secondary to HAVMs, associated with high cardiac output and heart failure. Precapillary hypertension is a rarer cause of PH in HHT patients, wherein cardiac output is normal or decreased, but pulmonary vascular resistance is increased due to the remodeling of small pulmonary arteries.[77]

Treatments for HAVMs include hepatic artery embolization and liver transplantation. Hepatic artery embolization reduces arteriovenous and arterioportal shunting and can alleviate heart failure and mesenteric steal syndrome.[78] However, it has been recommended that hepatic artery embolization be avoided if possible due to its relatively high association with morbidity and mortality, as well as the temporality of the alleviation of symptoms.[76] The majority of patients experience an alleviation of symptoms following liver transplant, although postoperative complications must be considered.[79],[80]

Gastrointestinal manifestations

Gastrointestinal bleeding is a common symptom of HHT, occurring in up to 33% of HHT patients and with an onset of about 50 years of age.[81] Gastrointestinal manifestations include esophageal, gastric, and small-bowel TeLs, small-bowel polyps and masses, and colonic vascular malformations.[82] Such vascular lesions can lead to chronic hemorrhage and anemia, requiring blood transfusion and/or iron supplementation.[83] The most common lesions occur in the stomach, especially of the fundus, and the small intestine.[82] In patients with HAVMs and associated portal hypertension, esophageal varices are also prone to hemorrhage.[82] Therefore, the international HHT guidelines advise the monitoring of hemoglobin and serum iron levels starting at 35 years of age and recommend that endoscopy be performed if anemia develops to an extent that is not explained by the severity of epistaxis.[76] In addition to supportive care, argon plasma coagulation and long-acting somatostatin analog therapy may be effective treatments for recurrent anemia and gastrointestinal hemorrhaging in patients with HHT.[84],[85]

Therapeutic treatment

While open and endovascular surgeries remain the mainstay for AVM treatment, insight into pathogenesis has given us options on how to potentially treat this condition medically. There are a number of drugs that have been proposed as therapeutic agents for the treatment of HHT, including antiangiogenic pharmaceuticals, as well as suggestions to repurpose commonly used drugs such as metformin and propranolol. A commonality between most of these is their antiangiogenic properties and the usage of endoglin and/or ALK1 as direct or indirect targets. These agents have a proven role in the treatment of epistaxis and have a potential role for managing AVMS located in high-risk areas where surgical therapy is associated with high risk of complication. They may also be useful for treating very sick patients with numerous comorbidities. The various available and potentially future therapies are included in [Table 1].


   Conclusion Top


A diagnosis of HHT on the basis of the international Curacao criteria should lead to a step-wise approach of patient care. First, the involvement of AVMs in specific organ systems, and second, their associated clinical presentations, should be considered as highlighted in [Table 3] and [Table 4]. The provider should ask the questions: Which other organ systems are expected to have AVM involvement? What pertinent symptoms need to be reviewed for each organ system and carefully examined on evaluation? Third, an attempt to identify the patient's subtype of HHT should be invoked, as natural history of disease will allow specific follow-up. Sequencing of patients in question can be especially helpful. It should be noted that there remains a significant number of patients who meet the Curaçao criteria but test negative for mutations in ACVRL1, ENG, MADH4, and GDF2, suggesting that there are HHT-causing mutations that have yet to be unveiled. Genomic analyses and next-generation sequencing of individuals who lack known mutations associated with HHT should facilitate discovery of novel genetic mutations and DNA modifications responsible for causing this disease. Fourth, an understanding of medications that are being tried or are in trials can add great value to the course of clinical management.
Table 3: Large arteriovenous malformations affecting visceral organs

Click here to view
Table 4: Manifestations secondary to arteriovenous malformations

Click here to view


Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published, and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Research quality and ethics statement

This case report did not require approval by the Institutional Review Board / Ethics Committee. The authors followed applicable EQUATOR Network (http://www.equator-network.org/) guidelines, specifically the CARE guideline, during the conduct of this research project.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.









[89]



 
   References Top

1.
Shovlin CL, Guttmacher AE, Buscarini E, Faughnan ME, Hyland RH, Westermann CJ, et al. Diagnostic criteria for hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome). Am J Med Genet 2000;91:66-7.  Back to cited text no. 1
    
2.
Dupuis-Girod S, Ginon I, Saurin JC, Marion D, Guillot E, Decullier E, et al. Bevacizumab in patients with hereditary hemorrhagic telangiectasia and severe hepatic vascular malformations and high cardiac output. JAMA 2012;307:948-55.  Back to cited text no. 2
    
3.
Vázquez C, Gonzalez ML, Ferraris A, Bandi JC, Serra MM. Bevacizumab for treating Hereditary Hemorrhagic Telangiectasia patients with severe hepatic involvement or refractory anemia. PLoS One 2020;15:e0228486.  Back to cited text no. 3
    
4.
Ruiz S, Chandakkar P, Zhao H, Papoin J, Chatterjee PK, Christen E, et al. Tacrolimus rescues the signaling and gene expression signature of endothelial ALK1 loss-of-function and improves HHT vascular pathology. Hum Mol Genet 2017;26:4786-98.  Back to cited text no. 4
    
5.
Sommer N, Droege F, Gamen KE, Geisthoff U, Gall H, Tello K, et al. Treatment with low-dose tacrolimus inhibits bleeding complications in a patient with hereditary hemorrhagic telangiectasia and pulmonary arterial hypertension. Pulm Circ 2019;9:2045894018805406.  Back to cited text no. 5
    
6.
Dupuis-Girod S, Fargeton AE, Grobost V, Rivière S, Beaudoin M, Decullier E, et al. Efficacy and Safety of a 0.1% Tacrolimus Nasal Ointment as a Treatment for Epistaxis in Hereditary Hemorrhagic Telangiectasia: A Double-Blind, Randomized, Placebo-Controlled, Multicenter Trial. J Clin Med. 2020;9:1262.  Back to cited text no. 6
    
7.
Ruiz S, Zhao H, Chandakkar P, Papoin J, Choi H, Nomura-Kitabayashi A, et al. Correcting Smad1/5/8, mTOR, and VEGFR2 treats pathology in hereditary hemorrhagic telangiectasia models. J Clin Invest 2020;130:942-57.  Back to cited text no. 7
    
8.
Skaro AI, Marotta PJ, McAlister VC. Regression of cutaneous and gastrointestinal telangiectasia with sirolimus and aspirin in a patient with hereditary hemorrhagic telangiectasia. Ann Intern Med 2006;144:226-7.  Back to cited text no. 8
    
9.
Taveira-DaSilva AM, Jones AM, Julien-Williams P, Stylianou M, Moss J. Long-term effect of sirolimus on serum vascular endothelial growth factor D levels in patients with lymphangioleiomyomatosis. Chest 2018;153:124-32.  Back to cited text no. 9
    
10.
Albiñana V, Recio-Poveda L, Zarrabeitia R, Bernabéu C, Botella LM. Propranolol as antiangiogenic candidate for the therapy of hereditary haemorrhagic telangiectasia. Thromb Haemost 2012;108:41-53.  Back to cited text no. 10
    
11.
Esteban-Casado S, Martín de Rosales Cabrera AM, Usarralde Pérez A, Martínez Simón JJ, Zhan Zhou E, Marcos Salazar MS, et al. Sclerotherapy and topical nasal propranolol: An effective and safe therapy for HHT-epistaxis. Laryngoscope 2019;129:2216-23.  Back to cited text no. 11
    
12.
Annabi B, Lachambre MP, Plouffe K, Moumdjian R, Béliveau R. Propranolol adrenergic blockade inhibits human brain endothelial cells tubulogenesis and matrix metalloproteinase-9 secretion. Pharmacol Res 2009;60:438-45.  Back to cited text no. 12
    
13.
Faughnan ME, Gossage JR, Chakinala MM, Oh SP, Kasthuri R, Hughes CCW, et al. Pazopanib may reduce bleeding in hereditary hemorrhagic telangiectasia. Angiogenesis 2019;22:145-55.  Back to cited text no. 13
    
14.
Fernandez-L A, Garrido-Martin EM, Sanz-Rodriguez F, Ramirez JR, Morales-Angulo C, Zarrabeitia R, et al. Therapeutic action of tranexamic acid in hereditary haemorrhagic telangiectasia (HHT): Regulation of ALK-1/endoglin pathway in endothelial cells. Thromb Haemost 2007;97:254-62.  Back to cited text no. 14
    
15.
Zhu JW, Ni YJ, Tong XY, Guo X, Wu XP, Lu ZF. Tranexamic acid inhibits angiogenesis and melanogenesis in vitro by targeting VEGF receptors. Int J Med Sci 2020;17:903-11.  Back to cited text no. 15
    
16.
Lebrin F, Srun S, Raymond K, Martin S, van den Brink S, Freitas C, et al. Thalidomide stimulates vessel maturation and reduces epistaxis in individuals with hereditary hemorrhagic telangiectasia. Nat Med 2010;16:420-8.  Back to cited text no. 16
    
17.
Komorowski J, Jerczyńska H, Siejka A, Barańska P, Ławnicka H, Pawłowska Z, et al. Effect of thalidomide affecting VEGF secretion, cell migration, adhesion and capillary tube formation of human endothelial EA. hy 926 cells. Life Sci 2006;78:2558-63.  Back to cited text no. 17
    
18.
Ge ZZ, Chen HM, Gao YJ, Liu WZ, Xu CH, Tan HH, et al. Efficacy of thalidomide for refractory gastrointestinal bleeding from vascular malformation. Gastroenterology 2011;141:1629-370.  Back to cited text no. 18
    
19.
Kovacs-Sipos E, Holzmann D, Scherer T, Soyka MB. Nintedanib as a novel treatment option in hereditary haemorrhagic telangiectasia. BMJ Case Rep. 2017;2017:bcr2017219393.  Back to cited text no. 19
    
20.
Droege F, Thangavelu K, Lang S, Geisthoff U. Improvement in hereditary hemorrhagic telangiectasia after treatment with the multi-kinase inhibitor Sunitinib. Ann Hematol 2016;95:2077-8.  Back to cited text no. 20
    
21.
Ola R, Dubrac A, Han J, Zhang F, Fang JS, Larrivée B, et al. PI3 kinase inhibition improves vascular malformations in mouse models of hereditary haemorrhagic telangiectasia. Nat Commun 2016;7:13650.  Back to cited text no. 21
    
22.
Geisthoff UW, Nguyen HL, Hess D. Improvement in hereditary hemorrhagic telangiectasia after treatment with the phosphoinositide 3-kinase inhibitor BKM120. Ann Hematol 2014;93:703-4.  Back to cited text no. 22
    
23.
Yaniv E, Preis M, Hadar T, Shvero J, Haddad M. Antiestrogen therapy for hereditary hemorrhagic telangiectasia: A double-blind placebo-controlled clinical trial. Laryngoscope 2009;119:284-8.  Back to cited text no. 23
    
24.
Albiñana V, Bernabeu-Herrero ME, Zarrabeitia R, Bernabéu C, Botella LM. Estrogen therapy for hereditary haemorrhagic telangiectasia (HHT): Effects of raloxifene, on Endoglin and ALK1 expression in endothelial cells. Thromb Haemost 2010;103:525-34.  Back to cited text no. 24
    
25.
Zarrabeitia R, Ojeda-Fernandez L, Recio L, Bernabéu C, Parra JA, Albiñana V, et al. Bazedoxifene, a new orphan drug for the treatment of bleeding in hereditary haemorrhagic telangiectasia. Thromb Haemost 2016;115:1167-77.  Back to cited text no. 25
    
26.
Frenzel T, Lee CZ, Kim H, Quinnine NJ, Hashimoto T, Lawton MT, et al. Feasibility of minocycline and doxycycline use as potential vasculostatic therapy for brain vascular malformations: Pilot study of adverse events and tolerance. Cerebrovasc Dis 2008;25:157-63.  Back to cited text no. 26
    
27.
Hashimoto T, Matsumoto MM, Li JF, Lawton MT, Young WL, University of California, San Francisco, BAVM Study Group. Suppression of MMP-9 by doxycycline in brain arteriovenous malformations. BMC Neurol 2005;5:1.  Back to cited text no. 27
    
28.
Crist AM, Zhou X, Garai J, Lee AR, Thoele J, Ullmer C, et al. Angiopoietin-2 inhibition rescues arteriovenous malformation in a smad4 hereditary hemorrhagic telangiectasia mouse model. Circulation 2019;139:2049-63.  Back to cited text no. 28
    
29.
Kim YH, Kim MJ, Choe SW, Sprecher D, Lee YJ, P Oh S. Selective effects of oral antiangiogenic tyrosine kinase inhibitors on an animal model of hereditary hemorrhagic telangiectasia. J Thromb Haemost 2017;15:1095-102.  Back to cited text no. 29
    
30.
Lacout A, Marcy PY, El Hajjam M, Lacombe P. Metformin as possible therapy of pulmonary arterio venous malformation in HHT patients. Med Hypotheses 2015;85:245-8.  Back to cited text no. 30
    
31.
Nolan-Stevaux O, Zhong W, Culp S, Shaffer K, Hoover J, Wickramasinghe D, et al. Endoglin requirement for BMP9 signaling in endothelial cells reveals new mechanism of action for selective anti-endoglin antibodies. PLoS One 2012;7:e50920.  Back to cited text no. 31
    
32.
de Vinuesa AG, Bocci M, Pietras K, Ten Dijke P. Targeting tumour vasculature by inhibiting activin receptor-like kinase (ALK) 1 function. Biochem Soc Trans 2016;44:1142-9.  Back to cited text no. 32
    
33.
van Meeteren LA, Thorikay M, Bergqvist S, Pardali E, Stampino CG, Hu-Lowe D, et al. Anti-human activin receptor-like kinase 1 (ALK1) antibody attenuates bone morphogenetic protein 9 (BMP9)-induced ALK1 signaling and interferes with endothelial cell sprouting. J Biol Chem 2012;287:18551-61.  Back to cited text no. 33
    
34.
Zemankova L, Varejckova M, Dolezalova E, Fikrova P, Jezkova K, Rathouska J, et al. Atorvastatin-induced endothelial nitric oxide synthase expression in endothelial cells is mediated by endoglin. J Physiol Pharmacol 2015;66:403-13.  Back to cited text no. 34
    
35.
Marchuk DA, Guttmacher AE, Penner JA, Ganguly P. Report on the workshop on Hereditary Hemorrhagic Telangiectasia, July 10-11, 1997. Am J Med Genet 1998;76:269-73.  Back to cited text no. 35
    
36.
Dakeishi M, Shioya T, Wada Y, Shindo T, Otaka K, Manabe M, et al. Genetic epidemiology of hereditary hemorrhagic telangiectasia in a local community in the northern part of Japan. Hum Mutat 2002;19:140-8.  Back to cited text no. 36
    
37.
Donaldson JW, McKeever TM, Hall IP, Hubbard RB, Fogarty AW. The UK prevalence of hereditary haemorrhagic telangiectasia and its association with sex, socioeconomic status and region of residence: A population-based study. Thorax 2014;69:161-7.  Back to cited text no. 37
    
38.
Westermann CJ, Rosina AF, De Vries V, de Coteau PA. The prevalence and manifestations of hereditary hemorrhagic telangiectasia in the Afro-Caribbean population of the Netherlands Antilles: A family screening. Am J Med Genet A 2003;116A: 324-8.  Back to cited text no. 38
    
39.
McAllister KA, Grogg KM, Johnson DW, Gallione CJ, Baldwin MA, Jackson CE, et al. Endoglin, a TGF-beta binding protein of endothelial cells, is the gene for hereditary haemorrhagic telangiectasia type 1. Nat Genet 1994;8:345-51.  Back to cited text no. 39
    
40.
Bayrak-Toydemir P, McDonald J, Markewitz B, Lewin S, Miller F, Chou LS, et al. Genotype-phenotype correlation in hereditary hemorrhagic telangiectasia: Mutations and manifestations. Am J Med Genet A 2006;140:463-70.  Back to cited text no. 40
    
41.
Johnson DW, Berg JN, Baldwin MA, Gallione CJ, Marondel I, Yoon SJ, et al. Mutations in the activin receptor-like kinase 1 gene in hereditary haemorrhagic telangiectasia type 2. Nat Genet 1996;13:189-95.  Back to cited text no. 41
    
42.
Cole SG, Begbie ME, Wallace GM, Shovlin CL. A new locus for hereditary haemorrhagic telangiectasia (HHT3) maps to chromosome 5. J Med Genet 2005;42:577-82.  Back to cited text no. 42
    
43.
Wooderchak-Donahue WL, McDonald J, O'Fallon B, Upton PD, Li W, Roman BL, et al. BMP9 mutations cause a vascular-anomaly syndrome with phenotypic overlap with hereditary hemorrhagic telangiectasia. Am J Hum Genet 2013;93:530-7.  Back to cited text no. 43
    
44.
Gallione CJ, Repetto GM, Legius E, Rustgi AK, Schelley SL, Tejpar S, et al. A combined syndrome of juvenile polyposis and hereditary haemorrhagic telangiectasia associated with mutations in MADH4 (SMAD4). Lancet 2004;363:852-9.  Back to cited text no. 44
    
45.
Gedge F, McDonald J, Phansalkar A, Chou LS, Calderon F, Mao R, et al. Clinical and analytical sensitivities in hereditary hemorrhagic telangiectasia testing and a report of de novo mutations. J Mol Diagn 2007;9:258-65.  Back to cited text no. 45
    
46.
Ricard N, Ciais D, Levet S, Subileau M, Mallet C, Zimmers TA, et al. BMP9 and BMP10 are critical for postnatal retinal vascular remodeling. Blood 2012;119:6162-71.  Back to cited text no. 46
    
47.
Cunha SI, Magnusson PU, Dejana E, Lampugnani MG. Deregulated TGF-β/BMP signaling in vascular malformations. Circ Res 2017;121:981-99.  Back to cited text no. 47
    
48.
Rossi E, Smadja DM, Boscolo E, Langa C, Arevalo MA, Pericacho M, et al. Endoglin regulates mural cell adhesion in the circulatory system. Cell Mol Life Sci 2016;73:1715-39.  Back to cited text no. 48
    
49.
López-Novoa JM, Bernabeu C. The physiological role of endoglin in the cardiovascular system. Am J Physiol Heart Circ Physiol 2010;299: H959-74.  Back to cited text no. 49
    
50.
Mahmoud M, Allinson KR, Zhai Z, Oakenfull R, Ghandi P, Adams RH, et al. Pathogenesis of arteriovenous malformations in the absence of endoglin. Circ Res 2010;106:1425-33.  Back to cited text no. 50
    
51.
Park SO, Wankhede M, Lee YJ, Choi EJ, Fliess N, Choe SW, et al. Real-time imaging of de novo arteriovenous malformation in a mouse model of hereditary hemorrhagic telangiectasia. J Clin Invest 2009;119:3487-96.  Back to cited text no. 51
    
52.
Han C, Choe SW, Kim YH, Acharya AP, Keselowsky BG, Sorg BS, et al. VEGF neutralization can prevent and normalize arteriovenous malformations in an animal model for hereditary hemorrhagic telangiectasia 2. Angiogenesis 2014;17:823-30.  Back to cited text no. 52
    
53.
Majumdar S, McWilliams JP. Approach to Pulmonary Arteriovenous Malformations: A Comprehensive Update. J Clin Med. 2020;9:1927.  Back to cited text no. 53
    
54.
Dupuis-Girod S, Cottin V, Shovlin CL. The Lung in hereditary hemorrhagic telangiectasia. Respiration 2017;94:315-30.  Back to cited text no. 54
    
55.
Martínez-Quintana E, Rodríguez-González F, Gopar-Gopar S. Hereditary hemorrhagic telangiectasia and myocardial infarction. Int J Angiol 2016;25:e81-3.  Back to cited text no. 55
    
56.
White RI, Mitchell SE, Barth KH, Kaufman SL, Kadir S, Chang R, et al. Angioarchitecture of pulmonary arteriovenous malformations: An important consideration before embolotherapy. Am J Roentgenol 1983;140:681-6.  Back to cited text no. 56
    
57.
Biçakçioğlu P, Gülhan SŞ, Sayilir E, Ertürk H, Ağaçkiran Y, Kaya S, et al. Surgical treatment of pulmonary arteriovenous malformations. Turk J Med Sci 2017;47:161-6.  Back to cited text no. 57
    
58.
Haitjema T, Disch F, Overtoom TT, Westermann CJ, Lammers JW. Screening family members of patients with hereditary hemorrhagic telangiectasia. Am J Med 1995;99:519-24.  Back to cited text no. 58
    
59.
Fulbright RK, Chaloupka JC, Putman CM, Sze GK, Merriam MM, Lee GK, et al. MR of hereditary hemorrhagic telangiectasia: Prevalence and spectrum of cerebrovascular malformations. AJNR Am J Neuroradiol 1998;19:477-84.  Back to cited text no. 59
    
60.
Krings T, Kim H, Power S, Nelson J, Faughnan ME, Young WL, et al. Neurovascular manifestations in hereditary hemorrhagic telangiectasia: Imaging features and genotype-phenotype correlations. AJNR Am J Neuroradiol 2015;36:863-70.  Back to cited text no. 60
    
61.
Kim H, Nelson J, Krings T, terBrugge KG, McCulloch CE, Lawton MT, et al. Hemorrhage rates from brain arteriovenous malformation in patients with hereditary hemorrhagic telangiectasia. Stroke 2015;46:1362-4.  Back to cited text no. 61
    
62.
Brinjikji W, Iyer VN, Sorenson T, Lanzino G. Cerebrovascular manifestations of hereditary hemorrhagic telangiectasia. Stroke 2015;46:3329-37.  Back to cited text no. 62
    
63.
Garcia-Monaco R, De Victor D, Mann C, Hannedouche A, Terbrugge K, Lasjaunias P. Congestive cardiac manifestations from cerebrocranial arteriovenous shunts. Endovascular management in 30 children. Childs Nerv Syst 1991;7:48-52.  Back to cited text no. 63
    
64.
Lee JS, Oh CW, Bang JS, Kwon OK, Hwang G. Intracranial pial arteriovenous fistula presenting with hemorrhage: A case report. J Cerebrovasc Endovasc Neurosurg 2012;14:305-8.  Back to cited text no. 64
    
65.
Poisson A, Vasdev A, Brunelle F, Plauchu H, Dupuis-Girod S, French Italian HHT network. Acute paraplegia due to spinal arteriovenous fistula in two patients with hereditary hemorrhagic telangiectasia. Eur J Pediatr 2009;168:135-9.  Back to cited text no. 65
    
66.
Cullen S, Alvarez H, Rodesch G, Lasjaunias P. Spinal arteriovenous shunts presenting before 2 years of age: Analysis of 13 cases. Childs Nerv Syst 2006;22:1103-10.  Back to cited text no. 66
    
67.
Kjeldsen AD, Tørring PM, Nissen H, Andersen PE. Cerebral abscesses among Danish patients with hereditary haemorrhagic telangiectasia. Acta Neurol Scand 2014;129:192-7.  Back to cited text no. 67
    
68.
Shovlin CL, Jackson JE, Bamford KB, Jenkins IH, Benjamin AR, Ramadan H, et al. Primary determinants of ischaemic stroke/brain abscess risks are independent of severity of pulmonary arteriovenous malformations in hereditary haemorrhagic telangiectasia. Thorax 2008;63:259-66.  Back to cited text no. 68
    
69.
Kuehl HK, Caselitz M, Hasenkamp S, Wagner S, El-Harith el-HA, Manns MP, et al. Hepatic manifestation is associated with ALK1 in hereditary hemorrhagic telangiectasia: Identification of five novel ALK1 and one novel ENG mutations. Hum Mutat 2005;25:320.  Back to cited text no. 69
    
70.
Buscarini E, Danesino C, Olivieri C, Lupinacci G, De Grazia F, Reduzzi L, et al. Doppler ultrasonographic grading of hepatic vascular malformations in hereditary hemorrhagic telangiectasia–results of extensive screening. Ultraschall Med 2004;25:348-55.  Back to cited text no. 70
    
71.
Memeo M, Stabile Ianora AA, Scardapane A, Suppressa P, Cirulli A, Sabbà C, et al. Hereditary haemorrhagic telangiectasia: Study of hepatic vascular alterations with multi-detector row helical CT and reconstruction programs. Radiol Med 2005;109:125-38.  Back to cited text no. 71
    
72.
Khalid SK, Garcia-Tsao G. Hepatic vascular malformations in hereditary hemorrhagic telangiectasia. Semin Liver Dis 2008;28:247-58.  Back to cited text no. 72
    
73.
Buscarini E, Leandro G, Conte D, Danesino C, Daina E, Manfredi G, et al. Natural history and outcome of hepatic vascular malformations in a large cohort of patients with hereditary hemorrhagic teleangiectasia. Dig Dis Sci 2011;56:2166-78.  Back to cited text no. 73
    
74.
Garcia-Tsao G, Korzenik JR, Young L, Henderson KJ, Jain D, Byrd B, et al. Liver disease in patients with hereditary hemorrhagic telangiectasia. N Engl J Med 2000;343:931-6.  Back to cited text no. 74
    
75.
Kjeldsen AD, Vase P, Green A. Hereditary haemorrhagic telangiectasia: A population-based study of prevalence and mortality in Danish patients. J Intern Med 1999;245:31-9.  Back to cited text no. 75
    
76.
Faughnan ME, Palda VA, Garcia-Tsao G, Geisthoff UW, McDonald J, Proctor DD, et al. International guidelines for the diagnosis and management of hereditary haemorrhagic telangiectasia. J Med Genet 2011;48:73-87.  Back to cited text no. 76
    
77.
Circo S, Gossage JR. Pulmonary vascular complications of hereditary haemorrhagic telangiectasia. Curr Opin Pulm Med 2014;20:421-8.  Back to cited text no. 77
    
78.
Chavan A, Caselitz M, Gratz KF, Lotz J, Kirchhoff T, Piso P, et al. Hepatic artery embolization for treatment of patients with hereditary hemorrhagic telangiectasia and symptomatic hepatic vascular malformations. Eur Radiol 2004;14:2079-85.  Back to cited text no. 78
    
79.
Lerut J, Orlando G, Adam R, Sabbà C, Pfitzmann R, Klempnauer J, et al. Liver transplantation for hereditary hemorrhagic telangiectasia: Report of the European liver transplant registry. Ann Surg 2006;244:854-62.  Back to cited text no. 79
    
80.
Felli E, Addeo P, Faitot F, Nappo G, Oncioiu C, Bachellier P. Liver transplantation for hereditary hemorrhagic telangiectasia: A systematic review. HPB (Oxford) 2017;19:567-72.  Back to cited text no. 80
    
81.
Kjeldsen AD, Kjeldsen J. Gastrointestinal bleeding in patients with hereditary hemorrhagic telangiectasia. Am J Gastroenterol 2000;95:415-8.  Back to cited text no. 81
    
82.
Jackson SB, Villano NP, Benhammou JN, Lewis M, Pisegna JR, Padua D. Gastrointestinal manifestations of hereditary hemorrhagic telangiectasia (HHT): A systematic review of the literature. Dig Dis Sci 2017;62:2623-30.  Back to cited text no. 82
    
83.
Karlsson T, Cherif H. Effect of intravenous iron supplementation on iron stores in non-anemic iron-deficient patients with hereditary hemorrhagic telangiectasia. Hematol Rep 2016;8:6348.  Back to cited text no. 83
    
84.
Sato Y, Takayama T, Takahari D, Sagawa T, Sato T, Abe S, et al. Successful treatment for gastro-intestinal bleeding of Osler-Weber-Rendu disease by argon plasma coagulation using double-balloon enteroscopy. Endoscopy 2008;40 Suppl 2:E228-9.  Back to cited text no. 84
    
85.
Hutchinson JM, Jennings JS, Jones RL. Long-acting somatostatin analogue therapy in obscure-overt gastrointestinal bleeding in noncirrhotic portal hypertension: A case report and literature review. Eur J Gastroenterol Hepatol 2010;22:754-8.  Back to cited text no. 85
    
86.
van Gent MW, Post MC, Snijder RJ, Westermann CJ, Plokker HW, Mager JJ. Real prevalence of pulmonary right-to-left shunt according to genotype in patients with hereditary hemorrhagic telangiectasia: A transthoracic contrast echocardiography study. Chest 2010;138:833-9.  Back to cited text no. 86
    
87.
Ianora AA, Memeo M, Sabba C, Cirulli A, Rotondo A, Angelelli G. Hereditary hemorrhagic telangiectasia: Multi-detector row helical CT assessment of hepatic involvement. Radiology 2004;230:250-9.  Back to cited text no. 87
    
88.
Krings T, Ozanne A, Chng SM, Alvarez H, Rodesch G, Lasjaunias PL. Neurovascular phenotypes in hereditary haemorrhagic telangiectasia patients according to age. Review of 50 consecutive patients aged 1 day-60 years. Neuroradiology 2005;47:711-20.  Back to cited text no. 88
    
89.
Garcia-Tsao G. Liver involvement in hereditary hemorrhagic telangiectasia (HHT). J Hepatol 2007;46:499-507.  Back to cited text no. 89
    


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
   Introduction
   Case Report
   Methods
   Discussion
   Conclusion
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed222    
    Printed12    
    Emailed0    
    PDF Downloaded14    
    Comments [Add]    

Recommend this journal