Diffuse Pulmonary Arteriovenous Malformations Research Articles

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.

Cyanosis in a Previously Well Child.

Cyanosis in a Previously Well Child.

Hemangioma - A pointer to Abernethy syndrome?

Diffuse pulmonary arteriovenous malformations or pulmonary arterial hypertension (PAH) may result from congenital portosystemic venous shunts. Hemangioma as a physical sign of congenital portosystemic shunts (like Abernethy syndrome) has not been described. I report two children (one with severe cyanosis from pulmonary arteriovenous malformations and the other with severe PAH) with cutaneous hemangioma and Abernethy syndrome. Hemangioma may be a clinical pointer to portosystemic shunts even in the absence of obvious liver disease.

Abernethy malformation: Our experience from a tertiary cardiac care center and review of literature.

Abernethy malformation, also called as congenital extrahepatic portosystemic venous shunt, is a rare anomaly involving the portal venous system. Although rare, it is increasingly being reported and is important to diagnose given the adverse clinical consequences in untreated patients. It has myriad of clinical presentations, from being completely asymptomatic to causing hepatic carcinoma, hepatic encephalopathy, severe pulmonary hypertension, and diffuse pulmonary arteriovenous malformation. We describe our experience with five cases in a tertiary pediatric cardiac care center with Abernethy malformation, with review of literature and also discuss possible therapeutic implications.

Percutaneous intervention for diffuse pulmonary arteriovenous malformations by occlusion of large lobar pulmonary arteries

We present a case of an 8-year-old girl with bilateral, diffuse, lower lobe pulmonary arteriovenous malformations (PAVMs). These were initially treated by selective embolisation of the feeder arteries with coils and vascular plugs. Due to unsatisfactory results (persistent cyanosis and diffuse residual PAVMs), prolonged procedure time, high contrast dose and the fact that she was declined surgical resection by cardiothoracic surgery as she was perceived to be a high anaesthetic risk and surgical resection was presumed to be complex; a staged approach for occlusion of the left and right lower lobar pulmonary arteries with large vascular plugs was chosen.

Diffuse Pulmonary Arteriovenous Malformation in Children: Essential Value of Contrast Echocardiography in Diagnosis

Pulmonary arteriovenous malformations (PAVM) are abnormal communications between pulmonary arteries and pulmonary veins, and most commonly congenital in nature. Although rare, it is an important consideration in cyanotic patients of unknown cause. We report 3 cases with diffuse PAVM in children with different clinical manifestations and initial diagnosis was made by transthoracic contrast echocardiogram. Transthoracic contrast echocardiography (TTCE) is valuable as initial diagnostic tools for diffuse PAVM. Pulmonary angiography should be reserved for therapeutic purposes for PAVM rather than diagnostic.

A novel mutation in nuclear prelamin a recognition factor-like causes diffuse pulmonary arteriovenous malformations.

Two daughters in a Chinese consanguineous family were diagnosed as diffuse pulmonary arteriovenous malformations (PAVMs) and screened using whole exome sequencing (WES) and copy number variations (CNVs) chips. Though no mutation was found in the established causative genes of capillary malformation-AVMs (CM-AVMs) or PAVMs, Ser161Ile (hg19 NM_022493 c.482G>T) mutation in nuclear prelamin A recognition factor-like (NARFL) was identified. Ser161Ile mutation in NARFL conservation region was predicted to be deleterious and absent in 500 population controls and Exome Aggregation Consortium (ExAC) Database. And there was a dosage effect of the mutation on mRNA levels among family members and population controls, consistent with the instability of mutant mRNA in vitro. Accordingly, in lung tissue of the proband, NARFL protein expression was reduced but Fe3+ was overloaded with vascular endothelial growth factor (VEGF) overexpression. Furthermore, NARFL-knockdown cell lines demonstrated decreased activity of cytosolic aconitase, while NARFL-knockout zebrafish presented ectopic subintestinal vessels sprouts and upregulated VEGF. So we concluded that the Ser161Ile mutant induced NARFL deficiency and eventually diffuse PAVMs probably through VEGF pathway. In a word, we detected a functional mutation in NARFL, which might be the pathogenic gene in this pedigree.

An Incidental Finding of Severe Hypoxia in an Asymptomatic Patient Caused by Pulmonary Arteriovenous Malformations

SESSION TITLE: Pulmonary Vascular Disease Cases I SESSION TYPE: Affiliate Case Report Slide PRESENTED ON: Monday, October 26, 2015 at 11:00 AM - 12:00 PM INTRODUCTION: Pulmonary arteriovenous malformations (AVMs) are a rare clinical entity, especially when found in isolation with no underlying etiology. Literature review suggest that pulmonary AVMs are symptomatic in 91% of cases, with dyspnea in 82% and cyanosis in 79% of patients. Furthermore, 70% are also associated with Osler Weber Rendu Syndrome. We report a case of severe asymptomatic hypoxia, discovered incidentally on routine pre-operative evaluation, found to have isolated multiple large pulmonary AVMs. Workup failed to show any underlying etiology. CASE PRESENTATION: The patient is a 54 year old female, with a history of COPD and severe aortic valve insufficiency, diagnosed via an echocardiogram at another facility, referred to cardiovascular surgery at our hospital. During pre-surgical evaluation, she was found to be hypoxic, with oxygen saturation in the 80%s on 2L of oxygen by nasal cannula and was admitted. Upon admission, her oxygen saturation was at 85% on a non re-breather mask. She denied any symptoms. Physical examination was unremarkable. Laboratory values showed hemoglobin of 17.3g/L and hematocrit of 48.9%. Chest X-Ray revealed a mass like density in the right lower lobe (RLL). CT scan of the thorax with contrast was negative for pulmonary embolus but 4 AVMs in RLL and 2 in right upper lobe were identified. Further questioning and workup was negative for Osler-Weber-Rendu syndrome or other underlying etiology. Resting echo showed an EF of 70% and a Bubble Echocardiogram revealed extensive right to left shunting. Bubbles entered from the pulmonary venous drainage into the left atrium consistent with AVMs. She had a pulmonary angiogram and AVMs of the RLL were embolizedx2 and an amplatzer vascular occlusion plug was deployedx2. After embolization, the patient's oxygen saturation was at 95% on 6L of oxygen. A Transesophageal Echo showed moderate aortic insufficiency and she decided to forego cardiac surgery. DISCUSSION: Studies show most cases of pulmonary AVMs have an underlying etiology and are symptomatic in 91% of patients. Our case represents a patient with large asymptomatic pulmonary AVMs with no underlying etiology. CONCLUSIONS: It shows that in patients presenting with hypoxia with no clear underlying cause, pulmonary AVMs can be considered as a cause and that pulmonary angiogram and embolization of AVMS is the cornerstone of treatment of pulmonary AVMs. Reference #1: Faughnan ME, LUI YW, Wirth JA, et al. Diffuse Pulmonary arteriovenous malformations: characteristics and prognosis. Chest 2000; 117:31 DISCLOSURE: The following authors have nothing to disclose: Asad Omar No Product/Research Disclosure Information

Successful Lung Transplantation in a Case With Diffuse Pulmonary Arteriovenous Malformations and Hereditary Hemorrhagic Telangiectasia

Diffuse pulmonary arteriovenous malformations (AVMs) are associated with a poor prognosis and the therapeutic strategy remains controversial. We describe a pediatric patient with diffuse pulmonary AVMs associated with hereditary hemorrhagic telangiectasia (HHT), who presented with two cerebral AVMs in the parietal and occipital lobes as well. Of note, successful bilateral lung transplantation not only improved the hypoxemia but also resulted in size reduction of the cerebral AVMs. Although it is essential to consider involvements other than pulmonary AVMs, especially brain AVMs, to decide the indication, lung transplantation can be a viable therapeutic option for patients with diffuse pulmonary AVMs and HHT.

Lobar Embolization for Treatment of Diffuse Pulmonary Arteriovenous Malformations in Hereditary Hemorrhagic Telangiectasia: A Case Report

Pulmonary arteriovenous malformations (PAVMs) are abnormal communications between pulmonary arteries and pulmonary veins that are most commonly associated with hereditary hemorrhagic telangiectasia (HHT). The authors report a case of lobar artery embolization for the treatment of diffuse PAVMs in a patient with HHT who was experiencing recurrent transient ischemic attacks despite anticoagulation and multiple previous embolizations. The right lower lobar and interlobar arteries were embolized to achieve complete occlusion of multiple PAVMs in the right lower lobe and right middle lobe. In conclusion, lobar embolization can be considered for the relief of neurologic symptoms in patients with diffuse PAVMs.

Clinical Improvement After Banding of a Pulmonary Branch Artery in a Symptomatic Patient with Osler–Rendu–Weber Syndrome

We report a symptomatic newborn with Osler-Rendu-Weber syndrome, multiple and diffuse pulmonary arteriovenous malformations, and right-to-left shunting in the left lung. Right-to-left shunting was significantly decreased by selectively banding the left pulmonary branch artery and clipping one large feeding vessel so that total resection of the left lung could be avoided.

Results of Exercise Stress Testing in Patients with Diffuse Pulmonary Arteriovenous Malformations

Patients with diffuse pulmonary arteriovenous malformations (PAVMs) are subject to frequent complications and need to be followed closely. As part of this follow-up, we have employed exercise stress testing (EST) as an aid to assess their status. Twenty patients from a cohort of 35 with diffuse PAVMs have undergone EST using a standard cycle ergometer test. All patients had previously undergone pulmonary angiography, noncontrast chest computed tomography (CT), and repair of large focal PAVMs, prior to EST. Mean room air oxygen saturation at baseline and at maximum exercise (85% of maximum heart rate) were tabulated. Serial studies in six children and young adults were plotted by year and compared using the patient as their own control. Fourteen females and six males ranging in age from 4 to 50 years (mean 22 years) were studied. Baseline mean oxygen saturation was 84% and fell to 73% at maximum exercise. There was no significant difference between those with unilateral and bilateral involvement (P = 0.09). In four of the six patients with serial EST, the baseline and exercise oxygen saturations were quite stable. In the two patients who became symptomatic, with age, growth, and more activity, complete embolization of one or more segments of the lung improved their EST and functionality. Based on our previous work in patients with diffuse PAVMs, EST appears to offer a relatively safe and noninvasive method for assessing these patients. Our limited experience with serial EST suggests a good correlation with decreased functionality in these patients.

Diffuse Pulmonary Arteriovenous Malformations in Hereditary Hemorrhagic Telangiectasia: Long-term Results of Embolization According to the Extent of Lung Involvement

To review the safety of embolization in patients affected with hereditary hemorrhagic telangiectasia (HHT) presenting with diffuse pulmonary arteriovenous malformations (PAVMs). To correlate the initial presentation and long-term results of embolization according to the distribution of PAVMs.All consecutively treated patients were divided into three groups, according to the involvement of every subsegmental pulmonary artery (group 1), segmental artery (group 2), or both (group 3) of at least one lobe. Age, sex, initial clinical presentation, and Pao(2) were recorded before embolization. Per and postprocedural complications were carefully recorded. Clinical outcome and imaging follow-up were obtained at 6 months and annually thereafter.Thirty-nine patients (31 women, 8 men; mean age, 35 years), all of them with bilateral lung involvement, were treated. Group 1 consisted of 8, group 2 of 17, and group 3 of 14 patients. Dyspnea was present in 35 of the patients (90%) and cyanosis in 17 patients (44%). Preembolization Pao(2) was different between groups 1 (52.6 +/- 11.6 mm Hg) and 3 (70.7 +/- 14.1 mm Hg). Neurologic events were more frequently reported before treatment in group 1 (62.5%) than in group 2 (35%) or in group 3 (43%). Eighty percent of patients reported improvement in their dyspnea after embolization. Pao(2) levels improved more in group 2 than in groups 1 and 3. Eight ischemic or infectious complications occurred in 4 patients (10%) due to reperfusion of embolized PAVMs or enlargement of non-embolized PAVMs. Complete and partial treatment success was reported using CT scanning in 59% and 38% of cases, respectively.Dyspnea and paradoxical embolism are frequently encountered in HHT patients with diffuse PAVMs. Prevention of complications and improvement of dyspnea can be achieved after successful embolization in most patients. Better improvement of Pao(2) can be achieved in group 2.

New Definition and Natural History of Patients With Diffuse Pulmonary Arteriovenous Malformations: Twenty-Seven–Year Experience

Background Patients with diffuse pulmonary arteriovenous malformations (PAVM), a small but important subset of the PAVM population, have significant morbidity and mortality rates. Methods Thirty-six patients (21 female and 15 male) with diffuse PAVM from a cohort of 821 consecutive patients with PAVM were evaluated. Diffuse PAVM were categorized angiographically: involvement of one or more segmental pulmonary arteries in one or both lungs. Hereditary hemorrhagic telangiectasia (HHT) status, gender, presence or absence of large (≥ 3-mm diameter artery) focal PAVM, oxygen saturations, complications including hemoptysis, years of follow-up, and survival were tabulated. Results HHT was present in 29 of 36 patients (81%), and diffuse PAVM were more commonly bilateral (26 of 36 patients, 72%) than unilateral (10 of 36 patients, 28%) [p = 0.02]. Female gender was associated with bilateral diffuse PAVM (19 of 26 patients, 73%) [p = 0.01]. Focal PAVM were present in both groups but more commonly in patients with bilateral involvement (16 of 26 patients, 62%) [p = 0.02]. Initial oxygen saturations (pulse oximetry, standing) of patients with unilateral and bilateral diffuse PAVM were 87 ± 7% and 79 ± 8% (mean ± SD), respectively (p = 0.02). The last or current values for patients with unilateral and bilateral involvement are 95 ± 3% and 85 ± 7%, respectively (p < 0.0001). Nine deaths occurred, and all were in patients with bilateral involvement. Deaths were due to hemoptysis of bronchial artery origin (n = 2), hemorrhage from duodenal ulcer (n = 1), spontaneous liver necrosis (n = 3), brain hemorrhage (n = 1), brain abscess (n = 1), and operative death during attempted lung transplant (n = 1). Conclusions Patients with diffuse PAVM are a high-risk group, and yearly follow-up is recommended. Patients with diffuse pulmonary arteriovenous malformations (PAVM), a small but important subset of the PAVM population, have significant morbidity and mortality rates. Thirty-six patients (21 female and 15 male) with diffuse PAVM from a cohort of 821 consecutive patients with PAVM were evaluated. Diffuse PAVM were categorized angiographically: involvement of one or more segmental pulmonary arteries in one or both lungs. Hereditary hemorrhagic telangiectasia (HHT) status, gender, presence or absence of large (≥ 3-mm diameter artery) focal PAVM, oxygen saturations, complications including hemoptysis, years of follow-up, and survival were tabulated. HHT was present in 29 of 36 patients (81%), and diffuse PAVM were more commonly bilateral (26 of 36 patients, 72%) than unilateral (10 of 36 patients, 28%) [p = 0.02]. Female gender was associated with bilateral diffuse PAVM (19 of 26 patients, 73%) [p = 0.01]. Focal PAVM were present in both groups but more commonly in patients with bilateral involvement (16 of 26 patients, 62%) [p = 0.02]. Initial oxygen saturations (pulse oximetry, standing) of patients with unilateral and bilateral diffuse PAVM were 87 ± 7% and 79 ± 8% (mean ± SD), respectively (p = 0.02). The last or current values for patients with unilateral and bilateral involvement are 95 ± 3% and 85 ± 7%, respectively (p < 0.0001). Nine deaths occurred, and all were in patients with bilateral involvement. Deaths were due to hemoptysis of bronchial artery origin (n = 2), hemorrhage from duodenal ulcer (n = 1), spontaneous liver necrosis (n = 3), brain hemorrhage (n = 1), brain abscess (n = 1), and operative death during attempted lung transplant (n = 1). Patients with diffuse PAVM are a high-risk group, and yearly follow-up is recommended.

Early-life pulmonary arterial hypertension with subsequent development of diffuse pulmonary arteriovenous malformations in hereditary haemorrhagic telangiectasia type 1

The case history is presented of a male infant who was thought to have idiopathic pulmonary arterial hypertension (PAH) at 3 months of age. Subsequently the PAH decreased unexpectedly and...

Screening for children from families with Rendu-Osler-Weber disease: from geneticist to clinician.

Rendu-Osler-Weber syndrome, or hereditary hemorrhagic telangiectasia (HHT), is an autosomal dominant vascular disorder. The syndrome is characterized by telangiectases and arteriovenous malformations (AVMs) affecting skin, mucosae and internal organs. AVMs often remain clinically silent until provoking sudden serious complications, responsible for important morbidity and mortality which can occur both in adulthood and in children. The incidence of AVMs in HHT pediatric populations is unknown. To describe the screening protocol performed in the first genotypically confirmed HHT pediatric population and to estimate the incidence of occult brain, lung and liver AVMs and the different disease phenotypes. Molecular analysis was performed on 35 children, both symptomatic and asymptomatic, who were family members of probands with a previously identified mutation. Clinical-instrumental examination was performed on the mutation positive cases. Nasal telangiectases were investigated by anterior rhinoscopy. Contrast echocardiography and high resolution thoracic multislice computed tomography (CT) were performed to detect pulmonary arteriovenous malformations (PAVMs), and echo-color Doppler, and abdominal CT to detect hepatic arteriovenous malformations (HAVMs). Brain magnetic resonance imaging was utilized to detect cerebral angiopathic involvement. Molecular analysis demonstrated the mutation-carrier status in 22/35 children. Nineteen children, 12 of whom had epistaxis, positive to molecular testing underwent clinical evaluation. Nasal teleangiectases were found in 68%, mucocutaneous telangiectases (fingers, lips and oral cavity) in 79%, PAVMs in 53%, HAVMs in 47% and cerebral anteriovenous malformations and/or cerebral ischemic changes secondary to PAVMs in 12%. We evidenced a high incidence of HHT children with occult visceral lesions suggesting that a diagnostic screening may be indicated to appropriately treat brain and lung malformations.

A Case of Video-Assisted Thoracoscopic Pneumonectomy for Unilateral Diffuse Pulmonary Arteriovenous Malformation

Pulmonary arteriovenous malformations (PAVMs) are abnormal direct communications between the pulmonary arteries and veins. PAVMs may occur as either an isolated abnormality or in association with hereditary hemorrhagic telangiectasia, also called Osler-Weber-Rendu disease. The topic of PAVM has recently been extensively reviewed, but little is known about the clinical characteristics and course of patients having a diffuse pattern of the disease. Herein, is reported a case of unilateral diffuse PAVM in an 18 year old female patient, who underwent a right pneumonectomy, under a video-assisted thoracic surgery (VATS) approach, as the diffuse small pulmonary arteriovenous malformation involved the whole right lung.

Diffuse Pulmonary Arteriovenous Malformations: Characteristics and Prognosis

To study the clinical characteristics and prognosis of patients with diffuse pulmonary arteriovenous malformations (AVMs). Retrospective chart review of all patients (n = 16) with diffuse pulmonary AVMs seen at Yale New Haven Hospital, Johns Hopkins Hospital, and St. Michael's Hospital. Up-to-date follow-up information was obtained in all living patients. All patients were severely hypoxic. Neurologic complications (stroke or brain abscess) had occurred in 70% of patients by the time of diagnosis. During the follow-up period (mean, 6 years), three patients died and two others developed new neurologic complications. One of the deaths occurred perioperatively during lung transplantation. All patients underwent transcatheter embolotherapy of any large pulmonary AVMs. A selected group underwent pulmonary flow redistribution, a novel technique. Oxygenation did not improve significantly with embolotherapy of the larger AVMs, but there was a small significant improvement in those patients who underwent pulmonary flow redistribution. The majority (85%) of the living patients are currently working or studying full-time. Patients with diffuse pulmonary AVMs are at increased risk of neurologic complications. Transcatheter embolotherapy does not significantly improve the profound hypoxia, but it may reduce the risk of neurologic complications. Antibiotic prophylaxis is recommended for bacteremic procedures to prevent brain abscess. These patients can live for many years and lead productive lives. We do not recommend lung transplantation because survival with disease is difficult to predict and we have observed a perioperative transplant death.

Angioarchitecture of pulmonary arteriovenous malformations: an important consideration before embolotherapy.

Seventeen patients with 91 pulmonary arteriovenous malformations were evaluated by superselective angiography. Seventy-two (79%) of the malformations consisted of a simple type characterized by a single feeding artery draining into a bulbous, nonseptated aneurysmal communication with a single draining vein. The other 19 (21%) were complex, consisting of two or more pulmonary artery branches communicating with a bulbous septated aneurysmal part with two or more draining veins. Two patients had diffuse pulmonary arteriovenous malformations confined to multiple lobes of the lung. Balloon embolotherapy was effective in permanently obliterating the malformations in 14 patients treated. Therapy provided a sustained rise in arterial PO2 in the sitting position from a mean value of 44 mm Hg before occlusion to 65 mm Hg after occlusion. In three patients the process was too diffuse and/or the malformations too large for therapy to be effective. Complex pulmonary arteriovenous malformations required occlusion of all feeding arteries. Balloon embolotherapy provided an effective treatment for pulmonary arteriovenous malformations regardless of anatomic type.