Pulmonary Arteriovenous Malformations Research Articles

Percutaneous closure of pulmonary arteriovenous malformation and concomitant patent foramen ovale for cryptogenic stroke.

Percutaneous closure of pulmonary arteriovenous malformation and concomitant patent foramen ovale for cryptogenic stroke.

Unusual Cause of Hypoxemia during Pregnancy: New Diagnosis of Pulmonary Arteriovenous Malformations.

Unusual Cause of Hypoxemia during Pregnancy: New Diagnosis of Pulmonary Arteriovenous Malformations.

A Rare Case of Pulmonary Vascular Anomaly: MDCT Pulmonary Angiography in Diagnosis of Arteriovenous Malformation and Post-operative Imaging

Objective. To demonstrate the diagnostic algorithm and tactics of a surgical management of patients with pulmonary arteriovenous malformations.Materials and Methods. Based on a patient`s clinical data analysis, further examination tactic was chosen: in the pre and postoperative periods multispiral computed tomography (MSCT) angiopulmonography (on a Canon Aquillion Prime, Japan) was performed before and after intravenous administration of a iodine-containing contrast agent (Ultravist, 370 mg/ ml) at the rate of 1 ml/kg. Brain magnetic resonance tomography was performed on a Signa Voyager, General Electric, China, 1,5 Tl in the pulse sequences T1, T2, T2 FLAIR, DWI, SWAN in three mutually perpendicular planes with a slice thickness of 1-5 mm to examine the neurological complications. Interventional angiopulmonography was implemented by using General Electric Innova IGS530, France, angiographic system before and after endovascular occluder ("AMPLATZER Vascular PLUG 4", USA) and spirals ("2D-Helical-35" 9 mm in diameter and 2,7 mm long (4 spirals) and "Complex–Helical-18" 11 mm in diameter and 17 mm long, USA) placement. A literature review in Russian and English languages for the last 5 years was searched using CyberLeninka, PubMed Central, Elibrary data bases, by keywords: pulmonary arteriovenous malformation, MSCT angiopulmonography, endovascular treatment. The prospective longitudinal study was conducted in compliance with the principles of ethics in accordance with the Helsinki Declaration, and informed voluntary consent was obtained from the patient.Results. According to clinical and instrumental data, the tactics of combined endovascular treatment of a vascular malformation with subsequent postoperative control was collectively chosen. During the curation, an increase in saturation parameters, general wellbeing improvement, decrease in pulmonary pressure parameters, and diminution in the size of the right heart's parts were achieved.Conclusion. Arteriovenous malformations (AVMs) are rare vascular abnormalities that represent a pathological communication between the arterial and venous bed. The fistulous link leads to an abnormal discharge of blood, bypassing the physiological capillary channel. Radiation and interventional visualization methods play the most important diagnostic, and the latest — therapeutic role in management of patients and are able to establish indications for surgical intervention, prevent the occurrence of life-threating complications: abscesses, paradoxical embolism and heart attacks, progressive respiratory and heart failure.

Hybrid Procedural Management of Multiple Pulmonary Arteriovenous Malformations In A Patient With Hereditary Hemorrhagic Telangiectasia: A Case Report

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disorder characterized by vascular malformations, including Pulmonary Arteriovenous Malformations (PAVMs), which can lead to serious complications such as dyspnea and hemorrhage. This report features a 37-year-old woman with HHT and multiple PAVMs. The diagnosis was established through physical examination, laboratory tests, and thoracic multislice computed tomography (MSCT). A hybrid management approach was applied, including embolization and thoracotomy. The patient underwent successful embolization of the inferior segment, followed by thoracotomy to overcome procedural difficulties. After the intervention, the patient's symptoms improved significantly, with no recurrence. Management of complex PAVMs may require a combination of methods, including embolization and surgery. The importance of early detection and adaptive management in HHT patients is expressed, given the high risk of complications. Embolization is the primary treatment for PAVMs, but in complex cases, surgical intervention is required. This study emphasizes the importance of a hybrid management approach and early detection in preventing serious complications in HHT patients, as well as the need for the development of better clinical guidelines for the management of PAVMs.

Pulmonary arteriovenous malformation in children.

Pulmonary arteriovenous malformations (PAVMs) are rare abnormalities observed mainly in children with hereditary haemorrhagic telangiectasia (HHT). A majority of patients are asymptomatic at the time of detection. However, complications such as hypoxemia, stroke, cerebral abscess and massive hemoptysis can arise if larger PAVMs remain untreated. Larger PAVMs are usually managed successfully with embolization, although reperfusion of PAVMs have been reported post procedure. Early screening for PAVMs is recommended in asymptomatic children with HHT or those at risk for HHT. Longer term surveillance is also essential, to enable timely identification and management of PAVMs.

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

BackgroundHereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant inherited vascular disorder that can involve multiple organs, thus can be associated with so many clinical departments that proper screening and diagnosis of HHT are needed for providing better management of both patients and their family members.Case presentationWe present a 58-year-old female patient with recurrent paradoxical brain embolism due to HHT. She received aspirin therapy and underwent pulmonary arteriovenous malformation embolization, recovering well and discharged 3 days postoperatively. Though ischemic stroke caused by HHT-induced vascular disorders has been reported, our patient presented with both recurrent paradoxical brain embolisms and radiologic findings of bilateral globus pallidus manganese deposition at the same time, a combination rarely reported. We also review the literature on the clinical features and management of HHT for prompt diagnosis of this genetic disease behind paradoxical embolism.ConclusionsWhen patients with ischemic stroke, especially recurrent ischemic stroke, have combined arteriovenous malformations (AVMs) in single or multiple organs, or clues for AVMs like manganese deposition in globus pallidus, genetic diseases such as HHT may be the reason for ischemic stroke and shouldn’t be missed in the evaluation of embolic sources.

Commentary on Mosaic Copy Number Variation in a Patient with Cerebral and Pulmonary Arteriovenous Malformations and Recurrent Epistaxis.

Commentary on Mosaic Copy Number Variation in a Patient with Cerebral and Pulmonary Arteriovenous Malformations and Recurrent Epistaxis.

Mosaic Copy Number Variation in a Patient with Cerebral and Pulmonary Arteriovenous Malformations and Recurrent Epistaxis.

Mosaic Copy Number Variation in a Patient with Cerebral and Pulmonary Arteriovenous Malformations and Recurrent Epistaxis.

Graded Transthoracic Contrast Echocardiography After Pulmonary Arteriovenous Malformation Embolization: Can Chest CT Be Avoided in Patients With a Low-Grade Shunt?

BackgroundPulmonary arteriovenous malformations (PAVMs) are direct connections between the pulmonary artery and vein, creating right-to-left shunting (RLS). Embolization is indicated to prevent complications. Guidelines recommend follow-up chest CTs to confirm persistent occlusion and embolization of all treatable PAVMs. Graded transthoracic contrast echocardiography (TTCE) after PAVM embolization may offer a reliable alternative in a subgroup of patients while preventing radiation exposure. Research questionCan TTCE predict the need for additional embolotherapy in the post-embolization population as accurately as it does in treatment-naïve population? Study design and methodsSince 2018, follow-up after PAVM embolization at the study institution includes both TTCE and chest-CT after 6-12 months and every 3-5 years thereafter. Patients who underwent at least one follow-up TTCE and chest-CT were included. The indication for additional embolotherapy was discussed in a multidisciplinary team meeting. The primary outcome was the indication for additional embolotherapy in each RLS-grade. Additionally, the association between the RLS-grade and indication for additional embolotherapy was investigated. Results339 patients with 412 embolization procedures were included, median time to follow-up TTCE was 7.5 months. A RLS was present in 399 post-embolization TTCEs (97%): RLS grade 1 in 93 patients (23%), grade 2 in 149 patients (36%) and grade 3 in 157 patients (38%). In patients with a RLS grade 0-1, no treatable PAVMs were found on CT. In patients with RLS grade 2-3, 22 (15%) and 72 (46%) underwent additional embolizations. InterpretationThis study shows chest CT might be forgone in patients with an RLS grade 0-1 after PAVM embolization.

Multimodal ultrasound imaging for patent foramen ovale and pulmonary arteriovenous malformation in patients with cryptogenic stroke or migraine: A prospective diagnostic study.

Right-to-left shunt (RLS) caused by patent foramen ovale (PFO) and pulmonary arteriovenous malformations (PAVM) have been associated with a variety of diseases, and reliable techniques for detecting RLS are essential for diagnosis. This study aimed to compare the diagnostic accuracy of multimodal ultrasound imaging, including transthoracic echocardiography (TTE) plus contrast transthoracic echocardiography (CTTE) and transesophageal echocardiography (TEE) plus contrast transesophageal echocardiography (CTEE) for PFO and PAVM in patients with cryptogenic stroke or migraine. This prospective study enrolled patients with cryptogenic stroke or migraine admitted to First Hospital of Shanxi Medical University between July 2018 and April 2023. The TTE + CTTE + TEE + CTEE multimodal ultrasound imaging was defined as the gold standard. A total of 230 patients with cryptogenic stroke (108) or migraine (122) were enrolled. The TEE + CTEE generated a better area under the receiver operator characteristic (ROC) curves (AUC) than TTE + CTTE [0.995 (0.988-1.000) vs 0.975 (0.767-0.984), P < .001], indicating better identification of PFO and PAVM. The sensitivity and specificity of the TTE + CTTE were 89.4% and 85.7%, respectively, whereas the sensitivity and specificity of TEE + CTEE were 99.1% and 100%, respectively. The missed diagnosis rate of TTE + CTTE and TEE + CTEE was 65.7 % and 12.5%, respectively. The combination of TEE + CTEE may be a more reliable and sensitive tool to detect PFO and PAVM than TTE + CTTE in patients with cryptogenic stroke or migraine.

Pulmonary Aneurysmal Arteriovenous Malformation Treated With a Vascular Plug

Purpose To report a case of an asymptomatic patient with a pulmonary aneurysmal arterio-venous malformation successfully treated with a vascular plug. Case report An active 30-year-old male patient, residing at 3000 ft above sea level was referred due to an incidental finding on a CT scan of a 37 mm vascular mass localized in the lower lobe of the right lung, which corresponded to a pulmonary arteriovenous malformation with a single feeding artery. The patient was treated with an Amplatzer vascular plug, which effectively excluded the afferent vessel. An angio CT at 19 months follow-up revealed a hypodense residual mass of 9.0 mm in diameter with no arterial filling or venous drainage. The patient is fully active and remains asymptomatic at 24 months follow-up. Conclusion An unusual case of a pulmonary aneurysmal arteriovenous malformation successfully treated with a vascular plug is presented, highlighting the efficiency of this procedure.

Neurological and cardiopulmonary manifestations of pulmonary arteriovenous malformations.

Pulmonary arteriovenous malformations (PAVMs) are direct pulmonary artery-to-vein connections without pulmonary capillaries that result in intrapulmonary right-to-left blood shunts. Although most patients with PAVMs may be entirely asymptomatic, PAVMs can induce a series of complications involving the neurological, cardiovascular, and respiratory systems that can lead to catastrophic and often fatal clinical sequelae. In this study we review the available literature and summarize the reported PAVM-related complications among patients with PAVMs. The reviewed studies included observational studies, case studies, prospective studies, and cohort studies, and we provide an overview of PAVM-related neurological and cardiopulmonary manifestations, including stroke, cerebral abscess, transient ischemic attack, cerebral hemorrhage, migraine, seizure, dizziness, cardiac failure, arrhythmia, myocardial infarction, cough, hypoxemia, dyspnea, respiratory failure, hemoptysis, and hemothorax. Identifying and treating PAVMs before the presentation of major complication is important because this can prevent the occurrence of complications and can result in better outcomes. PAVM patients should thus be better evaluated and managed by a multidisciplinary team because they may be in a treatable phase prior to their condition becoming life-threatening.

Somatic mutations in arteriovenous malformations in hereditary hemorrhagic telangiectasia support a bi-allelic two-hit mutation mechanism of pathogenesis

Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder of vascular malformations characterized by mucocutaneous telangiectases and arteriovenous malformations (AVMs) in internal organs. HHT is caused by inheritance of a loss of function mutation in one of three genes. Although individuals with HHT are haploinsufficient for one of these genes throughout their entire body, rather than exhibiting a systemic vascular phenotype, vascular malformations occur as focal lesions in discrete anatomic locations. The inconsistency between genotype and phenotype has provoked debate over whether haploinsufficiency or a different mechanism gives rise to the vascular malformations. We previously showed that HHT-associated skin telangiectases develop by a two-hit mutation mechanism in an HHT gene. However, somatic mutations were identified in only half of the telangiectases, raising the question whether a second-hit somatic mutation is a necessary (required) event in HHT pathogenesis. Here, we show that another mechanism for the second hit is loss of heterozygosity across the chromosome bearing the germline mutation. Secondly, we investigate the two-hit mutation mechanism for internal organ AVMs, the source of much of the morbidity of HHT. Here, we identified somatic molecular genetic events in eight liver telangiectases, including point mutations and a loss of heterozygosity event. We also identified somatic mutations in one pulmonary AVM and two brain AVMs, confirming that mucocutaneous and internal organ vascular malformations undergo the same molecular mechanisms. Together, these data argue that bi-allelic loss of function in an HHT gene is a required event in the pathogenesis of HHT-associated vascular malformations.

Hereditary hemorrhagic telangiectasia - pediatric review.

Hereditary hemorrhagic telangiectasia (HHT) diagnostic and management approach for pediatrics underwent significant advances over the last couple of years. In 2020, new guidelines for HHT were published that included a pediatric section thus attracting special focus into the childhood presentation. Curacao criteria are specific, but not sensitive enough in children. Genetic testing is encouraged for all family members even if asymptomatic. Standardized scoring for epistaxis is strongly encouraged, as it allows monitoring and can stratify therapeutic approaches. Early screening for pulmonary and brain visceral arteriovenous malformations (AVMs) in pediatric patients with confirmed genetic alterations of HHT should be instituted. Graded trans-esophageal echocardiogram with agitated saline contrast can be used as screening method for pulmonary AVMs. As pulmonary AVMs can develop throughout lifetime, guidelines recommend repeated screening even in asymptomatic patients at least every 5 years. Signs of stroke in childhood are more subtle than in adults. Cerebral imaging in early childhood can identify brain AVMs that may benefit from early intervention. Embolization of high-risk pulmonary and cerebral AVMs should be performed at specialized centers even at pediatric age. One or two classic HHT telangiectasia can be considered diagnostic in children. Antibiotic prophylaxis with dental procedures continues to be recommended.

Pulmonary Arteriovenous Malformation in a Young Man

ABSTRACT A young man was diagnosed to have pulmonary arteriovenous malformation (PAVM) when he was admitted with COVID infection. He had no respiratory distress but his saturation at room air was 90%. Chest X-ray revealed non-homogenous opacity in left lower lobe (LLL). The heart was structurally normal on 2D echocardiography; the saline bubble study was however positive for extra-cardiac shunt. Computed tomography pulmonary angiography (CTPA) revealed PAVM with well-defined lobulated sac measuring 2.9 × 1.9 × 2.5 cm in lateral basal segment of LLL with segmental branch of left pulmonary artery as feeder vessel and it drained into left pulmonary vein. The patient was managed with percutaneous intervention using Amplatzer Vascular Plug II to occlude the feeder vessel. Post-intervention, patient’s saturation improved to 98% at room air and saline bubble study was negative for extra-cardiac shunt. CTPA at 06 weeks revealed complete thrombosis of the sac.

Quantitative plasma proteomic analysis in children after superior cavopulmonary anastomosis with pulmonary arteriovenous malformations.

Approximately 1000 children are born every year in the United States with one effective cardiac pumping chamber, or single ventricle heart disease. One of the early causes of mortality in this population is pulmonary arteriovenous malformations (PAVMs), which allow blood to bypass gas exchange in the lungs. PAVMs most frequently occur in children after superior cavopulmonary anastomosis (SCPA), a procedure that redirects venous blood from the upper body to the lungs. Because plasma proteins are in part responsible for directing angiogenesis, we hypothesized that differential protein concentrations would be observed in superior caval blood among children after SCPA according to PAVM status. We performed quantitative plasma proteomics from 11 children with PAVMs and in seven children without PAVMs; an additional 11 children with Fontan circulation were included as a reference. Among children with SCPA, there were no significant differences in the plasma proteomes for those with and without PAVMs. When comparing children with Fontan circulation to those with SCPA and PAVMs, 18 proteins exhibited differential expression (10 downregulated and eight upregulated) in superior caval plasma. These results suggest that factors other than, or in addition to, plasma proteins may be responsible for single ventricle patients' susceptibility to PAVMs after SCPA. IMPACT: What is the key message of your article? We did not identify significant differences in plasma proteins when comparing those children with and without pulmonary arteriovenous malformations (PAVMs) after superior cavopulmonary anastomosis (SCPA). What does it add to the existing literature? The etiology of PAVMs in this population is likely due to factors other than, or in addition to, differences in plasma proteins. What is the impact? Further studies are needed to identify causes of PAVMs among children after SCPA.

Molecular mechanisms and clinical manifestations of hereditary hemorrhagic telangiectasia

IntroductionHereditary Hemorrhagic Telangiectasia (HHT) is charactered by telangiectasia and arteriovenous malformations (AVMs). Recurrent visceral and mucocutaneous bleeding is frequently reported among HHT patients, while data on the prevalence of thrombosis remains limited. This study aims to describe the clinical manifestations and molecular biological characteristics of HHT patients. MethodsWe conducted a retrospective study at Ruijin Hospital, affiliated with Shanghai Jiao Tong University School of Medicine. A total of 24 HHT patients, observed between January 2019 and December 2023, were included. We recorded the biological, clinical, and therapeutic events, with particular attention to bleeding and thrombotic events. Gene mutation analysis and blood constituent measurements were performed. ResultsThe prevalence of bleeding among all HHT patients was 100 %, while thrombotic events were noted in 41.70 % of cases. Hepatic arteriovenous malformations (HAVMs) were identified in six patients, pulmonary arteriovenous malformations (PAVMs) in five patients, and cerebral arteriovenous malformations (CAVMs) in one patient. For patients with thrombosis, the discontinuation rates were 23.08 % for antiplatelet therapy and 33.33 % for anticoagulant therapy due to the increased risk of bleeding. Genetic mutations related to HHT were present in 16 patients, with ACVRL1 (activin A receptor-like type 1) mutations being the most frequent at 41.67 %, followed by ENG (endoglin) mutations at 20.83 %, and GDF2 (growth differentiation factor 2) mutations at 4.17 %. The incidence of PAVMs was 75.00 % in HHT1 patients with ENG mutations and 20 % in HHT2 patients with ACVRL1 mutations, while HAVMs occurred in 0 % and 40.00 % of these groups, respectively. Patients were divided into non-AVMs and AVMs groups. Compared to normal controls, von Willebrand factor (vWF) activity was significantly increased in all HHT patients (149.10 % vs. 90.65 %, P < 0.001). In the non-AVMs group, the median level of stromal cell-derived factor-1 (SDF-1) was significantly elevated (124.31 pg/mL vs. 2413.57 pg/mL, P < 0.05), while vWF antigen levels were markedly higher in the AVMs group (165.30 % vs. 130.60 %, P = 0.021). Further grouping of HHT patients based on bleeding and thrombosis phenotypes revealed that those with thrombosis had significantly higher median percentages of schistocytes (3.50 % vs. 0 %, P = 0.002), ferritin concentrations (318.50 μg/L vs. 115.50 μg/L, P = 0.001), and lactate dehydrogenase (LDH) levels (437 U/L vs. 105 U/L, P < 0.001). There were no significant differences in the activity of vWF, protein C (PC), protein S (PS), and factor VIII (FVIII) between the two groups. ConclusionThis study highlighted the complex relationship between arteriovenous malformations and genetic mutations in HHT patients. A comprehensive assessment of bleeding and thrombosis risks should be conducted for each HHT patient, additionally, further clinical studies are needed to explore the risk factors for thrombosis and anticoagulant-related bleeding in HHT.

Outcomes of Patients Undergoing the Kawashima Procedure at an Early Age: A Single Center Experience.

Previous reports have demonstrated the safety and efficacy of performing early Kawashima procedure (KP). Despite this, more recent studies have shown that the average age at the time of operation remains greater than one year of age. We report our experience with performing KP at an earlier age than previously reported. A retrospective review was completed of patients undergoing KP at a single center (January 2000 to June 2020). Clinical outcomes were examined. Initial palliation was performed in 11 out of 12 patients. Age and weight at time of KP were 8.25 months (6.4-9.7) and 7.7 kg (6.5-8.6). Intensive care unit stay was 3.16 days (1-12), overall length of stay was 9.5 days (3-22). There was one unplanned reoperation, and no mortality in the cohort. Discharge oxygen saturation was 88% (80%-98%). Seven patients developed pulmonary arteriovenous malformations (PAVMs) with six proceeding to hepatic vein incorporation (HVI). Interval time to development of PAVMs was 42.3 months (16-121). Four of the 12 patients were left with antegrade pulmonary blood flow (PBF) and three (75%) remain without PAVMs. Median follow-up was 10 years (1.5-22) with 11 of 12 (91.67%) survival for the cohort. The KP can be done at a younger age than previously reported with adequate early and late results. Most patients will go on to develop PAVMs and require HVI but leaving patients with some antegrade PBF is likely protective but will need further investigation to show definitive benefit.

Paradoxical embolic stroke during catheter-directed thrombolytics in a patient with massive pulmonary embolism

Abstract Paradoxical embolism represents a critical and potentially fatal complication that can be associated with pulmonary embolism (PE). This case details a unique case of massive PE, further complicated by embolic stroke occurring during catheter-directed thrombolytic therapy. There was no evidence of thrombosis during the initial evaluation with lower extremity Doppler ultrasound, abdominal computed tomography scan, and transthoracic echocardiography. Differentials for the source of the emboli include unrecognized left atrial appendage thrombus, pulmonary arteriovenous malformations, and a patent left foramen ovale. Our findings highlight the complexities and treatment challenges of massive PE.

Diffuse pulmonary arteriovenous malformation presenting with secondary polycythemia and headaches: a case report

BackgroundPulmonary arteriovenous malformations are a relatively uncommon medical condition, affecting roughly 1 in every 2500 individuals. Of those suffering from pulmonary arteriovenous malformations, 80% have an underlying genetic condition: hereditary hemorrhagic telangiectasia.Case presentationWe present the case of a 20-year-old Pakistani male with a history of persistent slower-onset frontal headaches that increased in severity within the course of the day. His hemoglobin was 18 g/dl, indicating polycythemia, for which he had undergone seven venesections in a month previously. His physical examination was unremarkable. His computed tomography scan depicted multiple dilated tortuous vessels with branching linear opacities in the right lower lobe of the lungs. The multiple feeding arteries were supplied by the right main pulmonary artery, and the large draining veins led to the right inferior pulmonary vein. This was identified as a diffuse pulmonary arteriovenous malformation. He was recommended for a right pulmonary artery angiogram. It showed multiple tortuous vessels with a nidus and large draining veins—features of a diffuse arteriovenous malformation in the right lower lobe of the lung consistent with the computed tomography scan. Embolization of two of these vessels feeding the arteriovenous malformation was conducted, using Amplatzer Vascular plug 2, whereas multiple pushable coils (five coils) were used for embolizing the third feeding vessel. This achieved 70–80% successful embolization of right pulmonary AVM; however, some residual flow was still seen in the arteriovenous malformation given the complexity of the lesion. Immediately after, his oxygen saturation improved from 78% to 96%.ConclusionDiffuse pulmonary arteriovenous malformations, as seen in this patient, are rare, accounting for less than 5% of total pulmonary arteriovenous malformations diagnosed. The patient presented with a complaint of progressive frontal headaches, which can be attributed to low oxygen saturation or the presence of a cerebral arteriovenous malformation. There was no history of hereditary hemorrhagic telangiectasia in the patient’s family. Furthermore, although most patients with hereditary hemorrhagic telangiectasia and hence pulmonary arteriovenous malformation have complaints of iron-deficiency anemia, our patient in contrast was suffering from polycythemia. This can be explained as a compensatory mechanism in hypoxemic conditions. Moreover, the patient had no complaint of hemoptysis or epistaxis, giving a varied presentation in comparison with a typical pulmonary arteriovenous malformation.