Management of pulmonary arteriovenous malformations

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

BACKGROUND

Pulmonary 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 PRESENTATION

We 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%.

CONCLUSION

Diffuse 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.

Use of Polyurethane-Covered Stents for Exclusion of Pulmonary Arteriovenous Malformations

PURPOSE

To evaluate the safety, technical success and short-term effectiveness of polyurethane-covered stent (PK Papyrus, BioTronik, Berlin) in the treatment of pulmonary arteriovenous malformations (PAVMs) that are not amenable to embolotherapy.

MATERIALS AND METHODS

In this IRB-approved, retrospective study, data from patients who received polyurethane-covered stents for exclusion of PAVMs were analyzed. The study included 5 patients (all women) with a median age of 40 years (range 25-60). Patients presented with hypoxemia, TIAs, and/or epistaxis; 4 were confirmed to have HHT. All had multiple PAVMs diagnosed on chest CT and underwent embolization with other devices in addition to the polyurethane-covered stent. The indication for stent placement in all cases was a short and/or tortuous feeding artery. Safety was assessed by immediate or short-term complications, e.g., migration, stent thrombosis, and fracture. Technical success was defined as the ability to accurately place the stent at the intended location. Effectiveness was defined as successful exclusion of PAVM with no perfusion across the AVM.

RESULTS

Technical success of stent placement was 100%. AVM exclusion rate was 80% after single stent deployment; in the case of incomplete exclusion, success was achieved using an overlapping stent to completely cover a second feeding artery. During the median follow-up period of 5 months (range 2-10), all stents remained patent, and AVMs were excluded without other complications.

CONCLUSION

Exclusion of PAVMs with polyurethane-covered stents is technically feasible, safe, and shows short-term effectiveness for PAVMs with a short/tortuous feeding artery when traditional embolization techniques are not possible.

A case of hemoptysis unveiling the unlikely culprit - pulmonary arteriovenous malformation

Pulmonary arteriovenous malformation (PAVM) is a rare vascular anomaly characterized by abnormal communication between the pulmonary artery and vein. It is a rare cause of hemoptysis. Computed tomographic angiography (CTA) has become the preferred and dependable diagnostic approach for identifying PAVM. PAVM embolization is the primary recommended treatment for this condition. We present a case of a 43-year-old male with a complex PAVM in the left lower lobe presenting with hemoptysis treated with an endovascular approach. Following the procedure, the patient's symptoms resolved.

Attention to pulmonary arteriovenous fistula in a case of transient hypoxemia and cerebral infarction during pregnancy: a case report and literature review

BACKGROUND

Pulmonary arteriovenous fistula is rare during pregnancy. Pulmonary arteriovenous fistula presents no pulmonary symptoms in most patients but can be exacerbated by pregnancy. If not diagnosed and treated promptly, pulmonary arteriovenous fistula can lead to respiratory failure, stroke, spontaneous hemothorax, or other fatal complications.

CASE PRESENTATION

A 29-year-old healthy pregnant woman presented with a transient drop in blood oxygen level of unknown cause during a routine examination at 34 weeks of gestation and during a cesarean section at 38 weeks of pregnancy. The patient's oxygen saturation quickly returned to normal and was not further investigated. On day 3 postpartum, the patient suddenly displayed slurred speech and right limb myasthenia. A head magnetic resonance imaging revealed cerebral infarction in the left basal ganglia. Subsequent computed tomography pulmonary arteriography revealed bilateral pulmonary arteriovenous fistula, which was likely the cause of cerebral infarction. The patient was transferred to the Department of Thoracic Surgery after one month of treatment and successfully underwent percutaneous embolization of pulmonary arteriovenous fistula.

CONCLUSION

Pulmonary arteriovenous fistula should not be neglected if a pregnant woman presents with transient hypoxemia and cerebral infarction. A transient decrease in pulse oxygen saturation that cannot be explained by common clinical causes can be an early warning sign of the disease. Early diagnosis and multidisciplinary management could improve the prognosis.

An Update on Embolization for Pulmonary Arteriovenous Malformations

Pulmonary arteriovenous malformations are abnormal connections between a pulmonary artery and a pulmonary vein that can lead to ischemic stroke and brain abscess due to right-to-left shunting of blood. Embolization is currently considered the first treatment option for pulmonary arteriovenous malformations owing to its minimal invasiveness. This review updates the indications and techniques for the embolization of pulmonary arteriovenous malformations and determines the persistence of pulmonary arteriovenous malformations following embolization based on the most recent literature.

Postembolization Persistence of Pulmonary Arteriovenous Malformations: A Retrospective Comparison of Coils and Amplatzer and Micro Vascular Plugs Using Propensity Score Weighting

BACKGROUND. Endovascular embolization of pulmonary arteriovenous malformations (PAVMs) was historically performed with embolic coils. The Amplatzer Vascular Plug device (AVP) was introduced for this purpose in 2007 and the Micro Vascular Plug device (MVP) in 2013. OBJECTIVE. The purpose of this study was to compare coils, AVPs, and MVPs in terms of risk of persistence after PAVM embolization by use of propensity score weighting to account for biases in device selection. METHODS. This retrospective study included 112 patients (78 women and girls, 34 men and boys; mean age, 45 years) who underwent embolization of 393 PAVMs with a single device type (coil, MVP, or AVP) from January 2003 to January 2020. Persistence was defined as less than 70% reduction in PAVM sac size or contrast enhancement of the sac on follow-up pulmonary CTA. A Cox proportional hazards regression model was used to assess associations between embolic device selection and PAVM persistence. Inverse propensity score weighting was used to account for differences in embolic device selection based on patient and PAVM characteristics. RESULTS. The median postembolization follow-up period was 1.5 years (IQR, 0.3-5.6 years). Persistence was found in 10% (41/393) of PAVMs, including 16% (34/207) of those treated with coils, 8% (7/88) of those treated with AVPs, and 0% (0/98) of those treated with MVPs. Variables associated with embolization device (p < .25) were age, sex, pediatric versus adult status, smoking status, PAVM complexity, PAVM laterality, number of feeding arteries, and feeding artery diameter. The Cox regression model incorporated inverse propensity score weighting to account for the differences between treatment groups in these variables and incorporated feeding artery diameter because of imbalance remaining after weighting. With coils as the referent, MVPs had a hazard ratio for persistence of less than 0.01 (95% CI, < 0.01 to < 0.01; p < .001), and AVPs had a hazard ratio of 0.37 (95% CI, 0.16-0.90; p = .03). CONCLUSION. The risk of persistence after PAVM embolization was significantly lower for MVPs alone than for coils or AVPs alone. In addition, the risk of persistence was lower for AVPs than for coils. CLINICAL IMPACT. The findings support the clinical use of MVPs as the preferred device for PAVM embolization over coils and polytetrafluoroethylene-covered plugs.

Spontaneous Hemothorax by Pulmonary Arteriovenous Malformation during Pregnancy

Background:  Pulmonary arteriovenous malformation (PAVM) is a rare vascular malformation that may cause hemothorax, especially during pregnancy. Case Description:  A 25-year-old woman presented sudden-onset left chest pain, dizziness, and dyspnea in the 27th week of gestation. Computed tomography angiography showed left pleural effusion with complete hemithorax opacification and an aneurysmal PAVM. She exhibited hemorrhagic shock and received emergency exploratory video-assisted thoracic surgery. A ruptured PAVM was identified and stopped by wedge resection in the upper lobe of the left lung. The patient's postoperative clinical course was uncomplicated. She subsequently delivered a healthy live baby vaginally at 41 weeks gestation. Conclusion:  PAVM should be considered in pregnant women with hemothorax. Emergency thoracoscopic surgery is the best treatment option.

Endovascular management of pulmonary arteriovenous malformations presenting as multiple brain abscesses

Pulmonary arteriovenous malformations (PAVMs) are rare vascular lesions characterised by abnormal connections between the pulmonary artery and vein bypassing the pulmonary capillary bed and causing right-to-left shunt. Paradoxical embolism is known to occur in these cases, leading to inoculation of septic focus in the systemic circulation. We report a case of multiple PAVMs who presented clinically with seizures and altered sensorium. On radiological work-up, multiple brain abscesses and large PAVMs were evident. The patient was successfully treated by endovascular embolisation of the PAVMs using a vascular plug and multiple coils. The patient showed complete clinical recovery and resolution of brain abscesses on follow-up.

The Role of Interventional Radiology in the Diagnosis and Treatment of Pulmonary Arteriovenous Malformations

Pulmonary arteriovenous malformations (PAVMs) are uncommon, predominantly congenital direct fistulous connections between the pulmonary arteries and pulmonary veins, resulting in a right to left shunt. Patients with PAVMs are usually asymptomatic with lesions detected incidentally when radiological imaging is performed for other indications. In this review, we discuss the classification and radiological features of PAVMs as well as their treatment and follow-up options, with a particular focus on percutaneous endovascular techniques and the evolution of the available equipment for treatment.

Noncontrast time-resolved pulmonary magnetic resonance angiography with consecutive beam saturation pulse and variable flip angles using three-dimensional fast spin echo: A preliminary study

To develop and validate a novel noncontrast time-resolved magnetic resonance angiography (NC TR-MRA) using consecutive beam pulses with variable flip angles for visualizing hemodynamics in the pulmonary artery, we performed phantom and volunteer studies and applied the novel NC TR-MRA to a 51-year-old woman with pulmonary arteriovenous malformation (PAVM).The novel NC TR-MRA sequence utilized consecutive multiple-beam saturation pulses with variable flip angles considering venous blood T1 relaxation to alter the visualized blood signal length. The flowing blood signal length is suppressed according to the number of beam saturation pulses. NC TR-MRA in each flow phase was assessed by subtracting the images with and without beam saturation pulses. In the flow phantom study, three flow velocities were used to simulate physiological pulmonary arterial blood flow. Signal profiles along the flow direction were evaluated in each flow phase. In the volunteer study, five healthy volunteers were recruited, and NC TR-MRA was applied to evaluate relationships between the flow-saturated time and signal enhancement rates. Four regions of interest (ROIs) were determined on the proximal and distal portions of the right basal artery. A patient with PAVM was included to validate whether a PAVM lesion could be visualized using NC TR-MRA. The visualized flow signal lengths extended proportionally with the number of beam saturation pulses in the steady-flow phantom at all velocities. In the volunteer study, NC TR-MRA images showed signal enhancement from the proximal to distal portions of the right basal artery with increase in the flow-saturated time. Signal enhancement rates in all ROIs were significantly positively correlated with the flow-saturated time (p < 0.001 in all ROIs). Further, the lesion and its hemodynamics could be explicitly visualized in the patient with PAVM. Hence, NC TR-MRA using beam saturation pulse can visualize the hemodynamics of the pulmonary artery and may be useful for diagnosing and following patients with PAVM.

Pulmonary Arteriovenous Malformations: What the Interventional Radiologist Should Know

Pulmonary arteriovenous malformations (PAVMs) are abnormal connections between the pulmonary artery and pulmonary vein bypassing the normal capillary bed causing a right-to-left shunt. The majority (80-90%) of PAVMs are associated with hereditary hemorrhagic telangiectasia (HHT). PAVMs may be asymptomatic or present with symptoms of hypoxia, shortness of breath, migraines, sequelae of paradoxical embolization, or rupture. Transcatheter embolization has become the standard of care. This article will review the clinical presentation, workup, genetics, imaging findings, embolization, complications, and follow-up for patients with PAVMs.

Endovascular Embolisation of Pulmonary Arteriovenous Malformation Using Amplatzer Vascular Plugs

Pulmonary arteriovenous malformation (PAVMs) are abnormal communications between pulmonary arteries and veins. The rarity of their occurrence, coupled with the risks they pose, including brain abscess, embolic stroke, and myocardial infarction, mandates that they should not be overlooked in the differential diagnosis of patients presenting with haemoptysis, dyspnea, clubbing, cyanosis, hypoxemia, or epistaxis.

We present the case of a 41-year-old local female who presented to our hospital as an outpatient with decreased oxygen saturation (SpO₂) of 70%-80% for the past two years with a final diagnosis of PAVM. The initial baseline workup showed polycythemia with a hemoglobin level of 19 mg/dL and raised hematocrit. She had extensive workup in the past two years for her polycythemia including gene mutation testing and cardiac workup which all turned out normal. Her chest X-ray (CXR) showed right lung opacity which was initially considered to be infective but it did not respond to antibiotic treatment. Later on, a CT scan of the chest was performed and findings were typical of a large PAVM which had two feeding arteries. The patient was referred to a cardiothoracic surgeon who sent the patient to the interventional radiology section for endovascular management.

The embolization procedure was then performed and both feeders were successfully embolised. After the procedure, the patient's SpO₂ levels were restored to 95%-96%, and no post-procedure complications were noted.

Acquired pulmonary arteriovenous malformation associated with bronchiectasis: a case report

Background

Pulmonary arteriovenous malformations are mostly caused by congenitally abnormal shunts between pulmonary arteries and pulmonary veins.

Case presentation

A 74-year-old Japanese woman with a history of bronchiectasis was admitted to our hospital because of dyspnea on exertion. Pulmonary angiography and reconstructed three-dimensional contrast-enhanced computed tomography images showed shunts between pulmonary arteries and pulmonary veins, indicating a diagnosis of pulmonary arteriovenous malformations. Coil embolization of the shunts was successful.

Conclusions

Our findings imply that bronchiectasis can cause pulmonary arteriovenous malformations, and thus patients who present with hypoxemia with bronchiectasis should be carefully evaluated.

CT Appearance of Pulmonary Arteriovenous Malformations and Mimics

A pulmonary arteriovenous malformation (PAVM) is a fistulous connection between a pulmonary artery and a pulmonary vein that bypasses the normal pulmonary capillary bed resulting in a right-to-left shunt. Because of the potential for paradoxical emboli, PAVMs are treated when their feeding arteries exceed 3 mm or patients are symptomatic. PAVMs are often encountered in patients with suspected hereditary hemorrhagic telangiectasia (HHT). Sporadic cases are uncommon. The radiologist may be called on to diagnose a PAVM after positive transthoracic contrast-enhanced echocardiography in a patient with suspected HHT to direct patient management and avoid potential complications. The radiologist may also be required to evaluate a potential PAVM detected at CT performed for other reasons. Through the authors' experiences at an HHT Center of Excellence in an area endemic with histoplasmosis, the authors have gained a unique perspective on the diagnosis of PAVMs and differentiation of PAVMs from their mimics. Understanding the CT appearance of PAVMs limits misdiagnosis, directs appropriate treatment, and allows subsequent family screening for HHT (and avoidance of unnecessary screening when a PAVM mimic is encountered). Both vascular and nonvascular pulmonary lesions can mimic PAVMs. Vascular mimics include fibrosing mediastinitis, venovenous collaterals, arterial collaterals, pulmonary artery pseudoaneurysms, hepatopulmonary vessels, Sheehan vessels, meandering pulmonary veins, and pulmonary vein varices. Nonvascular mimics include granulomas, nodules, mucoceles, bronchoceles, ground-glass opacities, and atelectasis. The authors review the CT technique for evaluating PAVMs and the appearance of PAVMs and their mimics. ^©RSNA, 2022.

Diagnosis and endovascular management of pulmonary arteriovenous malformations

Pulmonary arteriovenous malformations (PAVM) are abnormal communication of a branch of the pulmonary artery and pulmonary vein circumventing the intervening pulmonary capillaries. This results in a right-to-left (R-L) shunt and its related manifestations, which include hampered gas exchange leading to hypoxaemia, dyspnoea, paradoxical emboli leading to stroke, cerebral abscess, myocardial infarction and pulmonary haemorrhage due to rupture of the PAVM. Endovascular transcatheter embolization of the feeding vessels with coils or occlusion devices is the current standard care of treatment and preferred treatment modality. The articles aim to provide insights into the current trends in diagnosis, the current recommendations, approach and management options for patients with PAVM.

Arteriovenous Malformations in the Setting of Osler-Weber-Rendu: What the Radiologist Needs to Know

Osler-Weber-Rendu, also known as Hereditary Hemorrhagic Telangiectasia, is an autosomal dominant disease with phenotypic manifestations that include pulmonary, cerebrospinal, hepatic, and other visceral arteriovenous malformations (AVMs). Pulmonary AVMs can result in hypoxemia, hemoptysis, or stroke due to paradoxical embolism. The mainstay of treatment is transcatheter embolization. Central nervous system and abdominal visceral AVMs contribute to morbidity of the disease. Radiologists should be familiar with the imaging manifestations and treatment algorithm of AVMs in Osler-Weber-Rendu to effectively guide patient care.

A Rare Cause of Pulmonary Hypertension in a 4-Year-Old Toddler: Association of Cor Triatriatum Sinister and Pulmonary Arteriovenous Malformation

Cor triatriatum sinister is a rare congenital cardiac anomaly. The anomaly is caused by a fibromuscular membrane that divides the left atrium into two cavities. This membrane can lead to the obstruction of left atrial flow and also create pulmonary venous hypertension. Pulmonary arteriovenous malformation (PAVM) is notorious for its aberrant blood flow between the pulmonary arteries and veins. Herein, we report a case of a 4-year-old toddler who had a unique form of pulmonary hypertension presenting with cor triatriatum sinister and diffuse PAVM. After the surgical treatment of cor triatriatum sinister, both pulmonary arteriovenous malformation and pulmonary hypertension disappeared.

Young stroke: presentation of paradoxical embolism from an unrecognised PAVM

Young stroke patients should be investigated thoroughly to look for cardiac and extra-cardiac sources of emboli. We present a patient who was investigated for a cardiac source of emboli following an ischemic stroke. She was found to have a small patent foramen ovale (PFO) but due to the late appearances of bubbles on the bubble study it was thought that this was an incidental finding. Further investigation confirmed a PAVM was the source of emboli causing her stroke.

Smoking Significantly Impacts Persistence Rates in Embolized Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia

Background

Embolization is the standard of care for treatment of pulmonary arteriovenous malformations (PAVMs). Persistence of PAVMs after embolization occurs for undefined reasons but may include inflammation related to smoking in dysregulated angiogenesis.

Purpose

To determine whether patients with hereditary hemorrhagic telangiectasia (HHT) who smoke tobacco are more prone to PAVM persistence after embolization.

Materials and Methods

Patients with HHT treated for PAVMs between January 2000 and August 2017 were retrospectively identified. Only PAVMs with no previous treatment and patients with both clinical and imaging follow-up were included. Age, sex, PAVM characteristics (size, complexity, and location), embolization material used, microcatheter type, smoking history, active tobacco use, and other risk factors for arterial disease were analyzed by using a multivariate Cox proportional hazards model to determine risk factors for persistence.

Results

Five-year persistence-free survival rates in nonsmokers, smokers of 1–20 pack-years, and smokers of more than 20 pack-years were 12.2%, 21.9%, and 37.4% respectively. Smokers with more than 20 pack-years relative to nonsmokers had greater risk of persistence after adjusting for arterial feeder size (hazard ratio, 3.8; 95% confidence interval [CI]: 1.5, 10.0; P = .007). Patients who reported active tobacco use at the time of PAVM embolization had a 5-year cumulative incidence of persistence of 26.3% compared with 13.5% in inactive smokers. After adjusting for arterial feeder size, the risk of persistence was greater in tobacco users versus inactive smokers at the time of treatment (hazard ratio, 2.4; 95% CI: 1.2, 4.7; P = .01).

Conclusion

Smoking is associated with pulmonary arteriovenous malformation persistence after embolization in patients with hereditary hemorrhagic telangiectasia.

Online supplemental material is available for this article.

See also the editorial by Trerotola and Pyeritz in this issue.

Links Between Strokes and Hereditary Hemorrhagic Telangiectasia: A Population-Based Study

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is a disease of abnormal vasculature where patients are predisposed to strokes of multiple etiologies. We assessed yearly stroke incidence among Albertans with HHT and compared with the general population. Given the tendency for stroke in HHT patients, we expected HHT patients to have higher stroke incidence, in particular at younger ages.

METHODS

Population-based administrative health data on inpatient and ambulatory admissions were extracted over a 16-year period using International Classification of Diseases (ICD)-9 and ICD-10, Canada codes. We analyzed overall occurrence of strokes in Alberta by age, gender, stroke subtype, and diagnosis of HHT.

RESULTS

The age-standardized incidence rate of stroke in HHT was 450 per 100,000 compared with 260 per 100,000 in the general population with a rate ratio of 1.73 (95% confidence interval (CI) [1.046-2.842]). This study found a higher HHT prevalence in Alberta (1 in 3800) compared to the world average of 1 in 5000. Women were also more likely to be diagnosed with HHT, with a 3.25:1 female gender preponderance in the yearly incidence.InterpretationThis study not only shows that HHT patients are at higher risk of having a stroke but also quantifies that risk using an age-adjusted metric in Alberta. This province has a higher than expected disease burden of HHT, with the majority of cases affecting women. Our study found that acute ischemic strokes and transient ischemic attacks are far more common than hemorrhage in HHT. As HHT is a rare, multi-system, chronic disease, these patients should be referred to an HHT Centre of Excellence.

Pictorial review of the pulmonary vasculature: from arteries to veins

Pathology of the pulmonary vasculature involves an impressive array of both congenital and acquired conditions. While some of these disorders are benign, disruption of the pulmonary vasculature is often incompatible with life, making these conditions critical to identify on imaging. Many reviews of pulmonary vascular pathology approach the pulmonary arteries, pulmonary veins and bronchial arteries as individual topics. The goal of this review is to provide an integrated overview of the high-yield features of all major disorders of the pulmonary vasculature. This approach provides a more cohesive and comprehensive conceptualisation of respiratory pathology. In this review, we present both the salient clinical and imaging features of congenital and acquired disorders of the pulmonary vasculature, to assist the radiologist in identifying pathology and forming a robust differential diagnosis tailored to the presenting patient. TEACHING POINTS: • Abnormalities of the pulmonary vasculature are both congenital and acquired. • Pathology of a single pulmonary vascular territory often affects the entire pulmonary vasculature. • Anomalous pulmonary venous flow is named as a function of its location and severity. • Bronchial arteries often undergo dilatation secondary to cardio-respiratory pathology.

Pulmonary arteriovenous malformations: a radiological and clinical investigation of 136 patients with long-term follow-up

AIM

To assess the clinical outcome of patients with and without hereditary haemorrhagic telangiectasia (HHT) after embolisation of pulmonary arteriovenous malformations (PAVM) from a single national centre.

MATERIALS AND METHODS

The present register-based observational study including all patients with PAVM treated with embolisation at a reference centre for HHT and PAVM was undertaken over a 20-year period. Demographic data, HHT genotyping, clinical presentation, and outcome were registered. Patients with HHT were compared to the patients without HHT. Clinical examination, contrast-enhanced echocardiography, and computed tomography (CT) were used to assess the clinical outcome at follow-up.

RESULTS

One hundred and thirty-six patients with 339 PAVM underwent embolisation during the study period: 22 did not have HHT; 62% had HHT1, 10% had HHT2, 4% had JP-HHT, 8% had clinical HHT without identified genetic mutations. Solitary PAVM were more common among patients without HHT than with HHT. Mean follow-up after the first embolisation was 58 months. Mean age at first embolisation was 46.5 years, and at last follow-up 51.8 years. The clinical success without shunt at follow-up was 87%. The 30-day mortality related to the embolisation was 0%. Twenty patients died during follow-up (mean age 69 years). Most patients could be treated during one session, but many will need a long follow-up with repeated clinical examinations and embolisation.

CONCLUSION

The majority of patients referred for embolisation of PAVM had HHT. Multiple PAVM is associated with HHT. Patients with PAVM should be screened for HHT and patients with HHT for PAVM. Embolisation is a safe procedure with high clinical success.

Embolisation of pulmonary arteriovenous malformations - case series

Purpose

Pulmonary arteriovenous malformations (PAVM) are the direct communications between the pulmonary arteries and veins. These malformations can cause serious complications, and most of these patients should be treated. Herein we present our experience in the treatment of 18 cases of PAVM, treated with endovascular embolisation.

Material and methods

Eighteen patients with PAVMs underwent endovascular embolisation during a five-year period. Eight were male and 10 were female, with ages ranging from 16 to 65 years. Standard steel coils and vascular plug were used for embolisation.

Results

Embolisation was successful in 17 of 18 patients. Coiling was used in 10 patients, vascular plug in five, and both materials in two patients. All symptomatic patients with successful embolisation lost all their symptoms after treatment. Control angiography after embolisation showed a closure of AV shunt without migration of embolic material in all patients. Post-embolisation syndrome developed in four patients and late onset of pleural pain in three patients. There was no connection between pleural reaction and type of PAVM and embolic material.

Conclusions

Endovascular PAVM treatment is a minimally invasive, highly successful method with a low rate of only transitory complications.

Covered Stents in the Treatment of Pulmonary Arteriovenous Malformations

Seven patients with pulmonary arteriovenous malformations (PAVMs) not well suited to coil and/or plug treatment were treated with expanded polytetrafluoroethylene-covered stents. Mean diameter of treated arteries was 6 mm. Complete technical success was achieved in 7 of 8 PAVMs, 6 using only covered stents and 1 using both a covered and a bare stent owing to endoleak. In 1 patient, the parent vessel was sacrificed after identification of additional feeding vessels following stent graft placement. In 6 patients with median imaging follow-up of 8 months (range, 1-121 months), all stent grafts were patent, and all treated PAVMs were completely excluded without persistence.

Emergency video-assisted thoracic surgery for ruptured pulmonary arteriovenous malformation-related hemothorax in a pregnant woman: a case report

Background

Pulmonary arteriovenous malformations are rare vascular abnormalities that permit direct communication between the pulmonary artery and vein. During pregnancy, pulmonary arteriovenous malformation carries an increased risk of enlargement and rupture, which could lead to life-threatening hemothorax. This is the first case reporting successful thoracoscopic surgery for a pregnant woman with pulmonary arteriovenous malformation rupture-related hemothorax.

Case presentation

We present a case of a 32-year-old pregnant Asian woman (31 weeks’ gestation) whose pulmonary arteriovenous malformation ruptured, leading to right-sided spontaneous tension hemothorax. First, an emergency cesarean section for hypovolemic shock-related fetal distress was performed to save the baby. Immediately afterwards, video-assisted thoracic surgery with the single-incision approach allowed us to successfully obtain hemostasis and eradication of abnormal vasculature by conducting wedge resection of the pulmonary arteriovenous malformation.

Conclusions

Emergency thoracoscopic surgery for a pregnant woman with pulmonary arteriovenous malformation rupture-related hemothorax is safe and feasible. In contrast to transcatheter arterial embolization, video-assisted thoracic surgery could simultaneously achieve hemostasis for prevention of mortality, eradication of abnormal vasculature, and removal of massive thrombi.

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

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

Emergency Computed Tomography Angiogram of the Chest, Abdomen, and Pelvis

In the setting of blunt trauma, the rapid assessment of internal injuries is essential to prevent potentially fatal outcomes. Computed tomography is a useful diagnostic tool for both screening and diagnosis. In addition to trauma, acute chest syndromes often warrant emergent computed tomographic angiography, looking for etiologies such as aortic aneurysms or complications of aortic aneurysms, or both, pulmonary emboli, as well as other acute vascular process like aortic dissection and Takayasu aortitis. With continued improvements in diagnostic imaging, computed tomographic angiography of the chest, abdominal and pelvis proves to be an effective modality to image the aorta and other major vascular structures.

A case of pulmonary arteriovenous malformation: role of interventional radiology in diagnosis and treatment

Pulmonary arterio-venous malformations (PAVMs) are abnormal pulmonary arteries and pulmonary veins communicating directly without interposition of a capillary bed and about 80-90% of patients with PAVMs eventually may present with hereditary hemorrhagic telangiectasia (HHT), remaining ones are sporadic cases. On the other hand, about 15-35% of HHT patients may present with PAVMs. The PAVMs have a tendency to grow and increase in size over time and various factors like puberty, pregnancy and pulmonary arterial hypertension (PAH) affect growth. This condition needs early diagnosis, aggressive management and vigilant follow up. Our article aims to review pulmonary AVMs as a rare cause of strokes in young patients. We will discuss the clinical presentation, diagnosis, complications, the therapeutic options and the follow up.

Surgical treatment of pulmonary arteriovenous malformations

BACKGROUND/AIM

Pulmonary arteriovenous malformations (PAVMs) are direct communications between the branches of pulmonary arteries and veins. This study evaluates surgically treated cases of pulmonary arteriovenous malformations.

MATERIALS AND METHODS

We retrospectively examined 41 cases of PAVM that were operated in our clinic between 1995 and 2012. We obtained the clinical, radiological, and surgical data of the patients from their files.

RESULTS

The 41 cases comprised 27 males and 14 females. Their mean age at diagnosis was 39.8 years (range: 9-71). The symptoms were hemoptysis in 28 cases, dyspnea in five, cough in three, and epistaxis in two; three patients were asymptomatic. Twenty-three right and 19 left posterolateral thoracotomies were performed, including one case which was operated bilaterally. Lower lobectomy was performed in 17 patients, lower lobectomy and lingulectomy in two, upper lobectomy in ten, middle lobectomy in two, segmentectomy in seven, and wedge resection in four. Postoperative histopathology was arteriovenous malformation in all cases.

CONCLUSION

PAVMs are rare clinical conditions. Surgery remains the first choice when embolization treatment cannot be performed or is not successful, in symptomatic and complicated patients with PAVM, and/or in cases where the PAVM diagnosis cannot be established.

Persistence in Coil-Embolized Pulmonary Arteriovenous Malformations with Feeding Artery Diameters of 3 mm or Less: A Retrospective Single-Center Observational Study

PURPOSE

To assess persistence in coil-embolized pulmonary arteriovenous malformations (PAVMs) with feeding artery diameters ≤ 3 mm.

MATERIALS AND METHODS

Fifty-eight patients (21 male, 37 female; mean age, 43 y; range, 13-71 y) with 141 simple-type PAVMs treated from 2004 to 2014 were analyzed retrospectively. Inclusion criteria were one or more PAVMs with feeding artery diameters ≤ 3 mm ("small PAVMs"), treatment with coil embolization, and presence of a follow-up chest computed tomographic (CT) angiogram at approximately 6 months. Feeding artery diameter, total coil length, and coil nest-to-PAVM sac distance were measured on arteriographic images. Coil packing density was estimated. Persistence was defined as less than 70% reduction in PAVM sac size and was assessed for each PAVM with respect to previous arteriogram or CT angiogram. Each variable was statistically tested for association with persistence.

RESULTS

On follow-up CT arteriography, 111 of 141 PAVMs (79%) showed a 70% or greater reduction in size of the sac and were deemed not persistent. The remaining 30 (21%) with unchanged or minimally reduced sac sizes were classified as persistent. Feeding artery diameter, coil size, quantity of coils, shape of coils, coil nest length, compaction, and visible packing density did not affect persistence, but coil nest-to-sac distance was directly correlated with persistence (P < .006). This result held true even with nest-to-sac distances of less than 1 cm.

CONCLUSIONS

Small PAVMs have a high persistence rate after coil embolotherapy. Most previously described risk factors for PAVM persistence do not seem to apply to these PAVMs, with the exception of coil nest-to-sac distance.

Hereditary Hemorrhagic Telangiectasia and Myocardial Infarction

Hereditary hemorrhagic telangiectasia, also known as Osler-Weber-Rendu syndrome, is an autosomal dominant genetic disorder that leads to epistaxis, gastrointestinal bleeding, iron deficiency anemia, and arteriovenous malformations at the lungs, the liver, and the brain. However, due to its rarity and its unspecific findings on routine examinations, diagnosis is not easy unless suspected due to hypoxemia or paradoxical embolism. We present a case of a 46-year-old-woman with hereditary hemorrhagic telangiectasia and hypoxemia who presented a myocardial infarction secondary to paradoxical embolism through pulmonary arteriovenous malformations.

Pulmonary arteriovenous malformation in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension is a morbid condition associated with complications such as hemoptysis, right heart failure, paradoxical embolism, and even death. There is no known association of chronic thromboembolic pulmonary hypertension with pulmonary arteriovenous malformation. Possible hypothesis for this association is an increased pulmonary vascular resistance leading to the compensatory formation of pulmonary arteriovenous malformation. We present one such case presenting with hemoptysis that was managed with endovascular treatment.

Pulmonary Arteriovenous Malformations and Risk of Stroke

Pulmonary arteriovenous malformations (PAVMs) are rare, with an estimated incidence of 2 to 3 cases per 100,000, with most PAVMs (50%-80%) occurring in patients with hereditary hemorrhagic telangiectasia. Hypoxemia and orthodeoxia are some of the more common clinical presentations. The estimated risk of stroke secondary to PAVMs is as high as 2.6% to 25.0%. A combination of chest radiograph and contrast echocardiography is a good screening evaluation in patients with suspected PAVMs. Transcatheter therapy is the most suitable therapeutic option in most patients with PAVMs, and a variety of devices can be used to occlude the PAVMs.

Isolated asymptomatic pulmonary arteriovenous malformation presenting with ischaemic stroke

Young onset stroke is uncommon, and may be due to conditions other than traditional vascular risk factors. A 42-year-old woman with an ischaemic stroke was found to have left atrial bubble study positivity on transthoracic echocardiogram (TTE) suggestive of patent foramen ovale, however she also had low peripheral oxygen saturation. Investigation revealed an isolated pulmonary arteriovenous malformation (PAVM), visible on admission chest radiograph. This can cause embolic stroke and is an alternate cause of the TTE findings. The PAVM was able to be closed via endovascular intervention, removing the shunt and therefore removing her risk of recurrent stroke events. This is a rare cause of embolic stroke in young people which can be easily missed on investigation yet is amenable to treatment.

Intrapulmonary arteriovenous malformation causing recurrent strokes

This case reveals a left pulmonary arteriovenous malformation (PAVM) as a cause of recurrent cerebral and cerebellar emboli. Extensive workup excluded other etiologies of emboli formation, and the patient was transferred to a tertiary care center for percutaneous embolotherapy. In the absence of a clear etiology, PAVM should be considered as a potential cause of recurrent cerebral emboli, especially in the absence of carotid disease, intracardiac thrombus, atrial septal defect, and patent foramen ovale. Diagnostic work-up for the PAVM can be cost effective and expedited by utilization of agitated saline contrast echocardiography, as noted in our case.

A rare case of pulmonary arterio-venous malformation with recurrent anemia: Hereditary hemorrhagic telangiectasia

Arteriovenous malformation (AVM) is a rare vascular anomaly of the lung, which manifests predominantly as dyspnea (due to right to left shunting) and paradoxical embolism. Hereditary Hemorrhagic Telangiectasia (HHT) being a rare genetic disorder is one of the most common causes of pulmonary arteriovenous malformation (PAVM). Here we report an interesting case of recurrent anemia in an elderly female, who was subsequently found to have multiple cutaneous and mucosal telangiectasias and a large pulmonary AVM.

Pulmonary arteriovascular malformation: a rare cause of unexplained hypoxia and acute dyspnoea in young patients

Pulmonary arteriovenous malformations (PAVMs) are anomalous vascular connections between arteries and veins in the lung and comprise of two types, simple and complex. PAVMs are associated with congenital conditions such as hereditary haemorrhagic telengiectasia along with acquired causes. We present a case of a 26-year-old man who presented with dyspnoea, palpitations and decreased oxygen saturation as an initial presentation of PAVM, which was treated successively with embolisation.

[Hereditary hemorrhagic telangiectasia. Report of a pediatric case]

Hereditary hemorrhagic telangiectasia, or Rendu-Osler-Weber syndrome, is an autosomal dominant multiorgan disorder. This multisystemic vascular dysplasia is determined by a mutation of one of two main genes, endoglin (ENG) or HHT1, or ACVRL1 or HHT2. These mutations induce vascular disorders that cause recurrent epistaxis and eventually multiple telangiectasia and arteriovenous visceral malformations. We report the case of a 7-year-old girl who developed severe hypoxemia due to multiple pulmonary arteriovenous malformations.

Cerebral arteriovenous malformation presenting with polycythemia vera: A case report and literature review

INTRODUCTION

Cerebral arteriovenous malformations (AVM) usually present with headache, hemorrhage, or seizure. Erythropoietin (EPO) has demonstrated protective effects against ischemia within the CNS.

PRESENTATION OF CASE

The authors report a patient with a cerebral AVM and concurrent polycythemia associated with elevated serum EPO. Systemic EPO levels declined acutely after resection of the patient's AVM, and the polycythemia resolved in the following months.

DISCUSSION

Polycythemia secondary to a cerebral AVM, in the absence of extra-cerebral vascular lesions, has not been described in the literature.

CONCLUSION

The authors explore the mechanisms by which this patient's cerebral AVM could have induced EPO production within the brain, manifesting as polycythemia.