Efficacy and Safety of Venous Sac Embolization With or Without Feeding Artery Embolization Versus Feeding Artery Embolization Alone in the Management of Pulmonary Arteriovenous Malformations: A Systematic Review and Meta-analysis

PURPOSE

To evaluate by meta-analysis the safety and efficacy of venous sac embolization (VSE) with or without feeding artery embolization versus feeding artery embolization (FAE) alone in the management of pulmonary arteriovenous malformations (PAVMs).

METHODS

This systematic review and meta-analysis was performed and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic literature search was performed in MEDLINE, Embase, and Scopus till August 31, 2021 to identify studies comparing the safety and efficacy of VSE with or without FAE versus FAE alone in PAVMs. The success of treatment was assessed by comparing the number of PAVMs with ≥70% decrease in the size of draining vein/sac between the 2 groups. The pooled odds ratio (OR) and 95% confidence interval (95% CI) were calculated using the random-effects inverse-variance model and were used to compare pooled therapeutic efficacy between the groups.

RESULTS

Three studies were found eligible for the meta-analysis. The included studies had a total of 169 patients (119 females and 50 males). The total number of PAVMs was 298, and hereditary hemorrhagic telangiectasia was present in 119 patients. The success of treatment was higher with VSE as compared to FAE (OR=3.54, 95% CI=1.66-7.56). The minor complications were similar in both groups, and one major complication occurred in the FAE group. More coils were used in the VSE group.

CONCLUSIONS

The present systematic review and meta-analysis has consolidated the evidence that VSE with or without FAE is more efficacious than FAE alone in the management of PAVMs without any increase in the associated risk of sac rupture or coil migration.

CLINICAL IMPACT

Until high-quality data from a prospective, multicentric, randomized controlled trial becomes available, the evidence consolidated by the present systematic review and meta-analysis showing the efficacy of venous sac embolization (with or without feeding artery embolization) over feeding artery embolization alone, can be used for clinical decision-making in the management of pulmonary arterio-venous malformations.

Prenatal diagnosis of pulmonary arteriovenous malformations with a postnatal diagnosis of Osler-Weber-Rendu syndrome

Hereditary Hemorrhagic Telangiectasia (HHT), commonly known as Osler-Weber-Rendu disease, is an autosomal dominant multisystemic vascular disease associated with approximately 70% of cases of pulmonary arteriovenous malformations (PAVMs). Prenatal cases of PAVMs typically present with pulmonary vein dilatation on ultrasonography. This study presents a prenatal diagnosis of PAVMs with enlarged right pulmonary vein, cardiomegaly, cystic-appearing areas in the right lung and subsequent confirmation of Osler-Weber-Rendu syndrome using autopsy and whole exom sequencing.

High risk of ischaemic stroke amongst patients with hereditary haemorrhagic telangiectasia

BACKGROUND AND PURPOSE

Hereditary haemorrhagic telangiectasia (HHT) is a genetic disease with fragile blood vessels and vascular malformations, potentially causing neurological manifestations, including stroke and cerebral abscesses. The study aimed to investigate neurological manifestations in the Danish HHT database, focusing on pulmonary arteriovenous malformations (PAVMs) as a risk factor for cerebral events.

METHODS

Retrospective analysis of the Danish HHT database was conducted, cross-referencing neurological outcomes with the Danish Apoplexy Register for accuracy. Patients were stratified by HHT type. Primary outcomes included ischaemic stroke, transient ischaemic attack and cerebral haemorrhage. Secondary outcomes comprised age, age at HHT diagnosis, age at cerebral ischaemic event, and PAVM and cerebral arteriovenous malformation status.

RESULTS

Six hundred and sixty-four HHT patients were included. PAVM was diagnosed in 54% of patients, with higher prevalence in HHT type 1 (70%) compared to HHT type 2 (34%) and juvenile polyposis HHT (66%). Ischaemic stroke or transient ischaemic attack occurred in 12.5%, with a higher risk associated with macroscopic PAVM. Logistic regression showed a nearly 10 times increased risk of ischaemic stroke with macroscopic PAVM. Cerebral abscesses occurred in 3.2% of patients, all with macroscopic PAVM. Incomplete PAVM closure increased cerebral abscess risk.

CONCLUSION

This study provides valuable insights into the prevalence of neurological manifestations and vascular events in HHT patients. The presence of PAVM was associated with an increased risk of ischaemic stroke, highlighting the importance of early screening and intervention. The findings emphasize the need for comprehensive management strategies targeting both vascular and neurological complications in HHT patients, especially regarding secondary stroke prevention.

An unusual approach for platypnea-orthodeoxia syndrome due to isolated pulmonary arteriovenous malformations

A 27-year-old man presented to the emergency department with complaints of syncope, dyspnea, and fatigue. Physical examination revealed left-sided mild hemiparesis, platypnea, and continuous murmur on right middle lobe lung auscultation.

Can aura migraine be elicited by isolated pulmonary arteriovenous fistula?-A case report

A pulmonary arteriovenous fistula (PAVM) is an abnormal blood vessel that creates a direct connection between a pulmonary artery and its tributary vein bypassing capillary filter, establishing as a consequence of a low-resistance right-to-left shunting (RLS). The vast majority of PAVMs are congenital appearing more often in females than in males. A great number of patients with PAVMs is suffering concurrently from hereditary hemorrhagic telangiectasia (HHT) whose incidence is around 1 in 5,000. Very few cases of acquired PAVMs have been described in the literature. Paradoxical embolism through PAVMs can cause systemic desaturation, cyanosis, and serious cerebrovascular ischemic events (transient ischemic attacks, strokes, and intracranial abscess), even when the abnormal blood vessel is small (diameter <3 mm). Notably, it has been reported a high prevalence of aura migraine (MHA) symptoms in patients with PAVMs and concomitant HHT. We described in this study the case of a young aura migraineur female patient without HHT in whom isolated PAVM below the detection limit of pulmonary angiography and chest computed tomography angiography (CTA) has been documented by contrast Transthoracic and Transesophageal Echocardiography (cTTE/TEE) showing a delayed (>17 s) RLS coming from left pulmonary veins to left atrium while a patent foramen ovale (PFO), small atrial septal defects or septum primum fenestration could not be detected despite several attempts. Contrast Transcranial Doppler (cTCD) confirmed a delayed (>16 s) RLS with two short "shower" patterns corroborating the diagnosis of an extra-cardiac RLS. During the right heart catheterization and pulmonary angiography, it was impossible to cross the interatrial septum with a multipurpose catheter. The patient was finally discharged with off-label thienopyridine agents (clopidogrel 75 mg die) in terms of primary prophylaxis for paradoxical right-to-left embolization of thrombotic material ultimately. Aura migraine symptoms were nearly abolished by P2Y12 platelet inhibition, suggesting a platelet-based mechanism. During 2 years of clinical follow-up on thienopyridine therapy, the resolution of aura migraine episodes was definitively accomplished with significant improvement in her quality of life.

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.

Recurrent erysipelas led to diagnosis of hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a risk of infection, such as by brain abscess associated with pulmonary arteriovenous malformations. However, association between HHT and recurrent erysipelas is not well described. HHT can cause vessel malformations in organs, leading to various serious outcomes. Prophylactic treatment is effective, but many people with HHT are undiagnosed. HHT is not described as a risk factor for soft tissue infection, but may increase the risk of serious infections requiring hospitalization. Our 72-year-old female patient was admitted for recurrent erysipelas. Pulmonary nodules indicated pulmonary arteriovenous fistula on chest computed tomography. By recognizing this combination, although seemingly unrelated problems, we could diagnose HHT and the patient could receive adequate treatment to prevent life-threatening events. The recurrent erysipelas was likely associated with HHT. Recurrent erysipelas is an important presentation which may facilitate early diagnosis of HHT.

Increases in oxygen saturation following discharge from Fontan palliation - an indicator of resolution of pulmonary arteriovenous malformations?

BACKGROUND

Pulmonary arteriovenous malformations in single ventricle congenital heart disease are poorly understood. Previous studies investigating pulmonary arteriovenous malformations predominantly focus on patients with heterotaxy syndrome and interrupted inferior caval vein. It is unknown if development and resolution of pulmonary arteriovenous malformations are similar for patients with and without heterotaxy syndrome.

METHODS

In this retrospective single-institution study, we identified patients with a history of single ventricle congenital heart disease and Fontan palliation. We then matched patients with heterotaxy syndrome (intact and interrupted inferior caval vein) and non-heterotaxy hypoplastic left heart syndrome. To compare development of pulmonary arteriovenous malformations, we identified the frequency of positive diagnoses pre-Fontan. To compare resolution of pulmonary arteriovenous malformations, we recorded oxygen saturation changes for 12 months following Fontan.

RESULTS

A total of 124 patients were included. Patients with heterotaxy and interrupted inferior caval vein were more likely to have a pre-Fontan contrast echocardiogram performed (p < 0.01) and more likely to be diagnosed with pulmonary arteriovenous malformations pre-Fontan (p < 0.01). There was no difference in oxygen saturation prior to Fontan, yet all patient groups had increased their oxygen saturations in the first year after Fontan discharge.

CONCLUSIONS

Pulmonary arteriovenous malformations are variably diagnosed prior to Fontan palliation; however, all study groups had increased oxygen saturations after Fontan discharge, potentially indicating resolution of pulmonary arteriovenous malformations in all groups. The prevalence of pulmonary arteriovenous malformations pre-Fontan is likely underestimated. A quantitative, systematic approach to diagnosis and follow-up of pulmonary arteriovenous malformations is needed to better understand susceptibility and pathophysiology.

Applicability of Transthoracic Contrast Echocardiography for the Diagnosis and Treatment of Idiopathic Pulmonary Arteriovenous Malformations

Objective: To explore the preferred test to screen for pulmonary arteriovenous malformations (PAVMs) and to predict the probability of interventional embolization. Methods: We performed a retrospective observational study evaluating patients with idiopathic PAVMs from 2009 to 2019. After clinical evaluation, a total of 105 patients were studied, including 71 patients with positive digital subtraction pulmonary angiography (DSPA) findings and 34 with negative DSPA findings. The following patient data were assessed: blood test, chest radiograph, transthoracic contrast echocardiography (TTCE), and DSPA findings. Results: The majority of patients with idiopathic PAVMs were female (66.2% with positive DSPA findings). We found a good κ-coefficient of 0.77 with strong consistency for inter observer agreement concerning the pulmonary right-to-left shunt (RLS) grade on TTCE, which was superior to conventional chest radiographs. The positive predictive value (PPV) of the radiographic features for PAVMs on DSPA was 0.83 (95% CI 0.64-1.0) and 0.44 for the possibility of embolization (95% CI 0.19-0.70). The PPV of the shunt grade of PAVMs on DSPA was 0.14 (95% CI 0.01-0.29) for grade 1, 0.74 (95% CI 0.60-0.88) for grade 2, and 0.97 (95% CI 0.92-1.0) for grade 3. The PPVs of pulmonary shunt grades 2 and 3 on TTCE for the possibility of embolization for PAVMs were 0.21 (95% CI, 0.05-0.36) and 0.87 (95% CI, 0.79-0.99), respectively. Conclusion: TTCE is the preferred screening test for PAVMs. The pulmonary RLS grade on TTCE not only identifies the likelihood of PAVMs but also predicts the probability for embolization.

Homozygous GDF2 nonsense mutations result in a loss of circulating BMP9 and BMP10 and are associated with either PAH or an "HHT-like" syndrome in children

Background

Disrupted endothelial BMP9/10 signaling may contribute to the pathophysiology of both hereditary hemorrhagic telangiectasia (HHT) and pulmonary arterial hypertension (PAH), yet loss of circulating BMP9 has not been confirmed in individuals with ultra‐rare homozygous GDF2 (BMP9 gene) nonsense mutations. We studied two pediatric patients homozygous for GDF2 (BMP9 gene) nonsense mutations: one with PAH (c.[76C>T];[76C>T] or p.[Gln26Ter];[Gln26Ter] and a new individual with pulmonary arteriovenous malformations (PAVMs; c.[835G>T];[835G>T] or p.[Glu279Ter];[Glu279Ter]); both with facial telangiectases.

Methods

Plasma samples were assayed for BMP9 and BMP10 by ELISA. In parallel, serum BMP activity was assayed using an endothelial BRE‐luciferase reporter cell line (HMEC1‐BRE). Proteins were expressed for assessment of secretion and processing.

Results

Plasma levels of both BMP9 and BMP10 were undetectable in the two homozygous index cases and this corresponded to low serum‐derived endothelial BMP activity in the patients. Measured BMP9 and BMP10 levels were reduced in the asymptomatic heterozygous p.[Glu279Ter] parents, but serum activity was normal. Although expression studies suggested alternate translation can be initiated at Met57 in the p.[Gln26Ter] mutant, this does not result in secretion of functional BMP9.

Conclusion

Collectively, these data show that homozygous GDF2 mutations, leading to a loss of circulating BMP9 and BMP10, can cause either pediatric PAH and/or “HHT‐like” telangiectases and PAVMs. Although patients reported to date have manifestations that overlap with those of HHT, none meet the Curaçao criteria for HHT and seem distinct from HHT in terms of the location and appearance of telangiectases, and a tendency for tiny, diffuse PAVMs.

The Lugones Procedure for Surgical Repair of Scimitar Syndrome: Preserved Growth in a Young Infant

Surgical repair of Scimitar syndrome is challenging, especially in small patients. Our images demonstrate that the pericardial tunnel technique is feasible even in low-weight patient and that it provides a good growth potential.

Safety of Catheter Embolization of Pulmonary Arteriovenous Malformations-Evaluation of Possible Cerebrovascular Embolism after Catheter Embolization of Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia/Osler Disease by Pre- and Post-Interventional DWI

Background. This paper aimed to prospectively evaluate the safety of embolization therapy of pulmonary arteriovenous malformations (PAVMs) for the detection of cerebral infarctions by pre- and post-interventional MRI. Method One hundred and five patients (male/female = 44/61; mean age 48.6+/−15.8; range 5–86) with pre-diagnosed PAVMs on contrast-enhanced MRA underwent embolization therapy. The number of PAVMs treated in each patient ranged from 1–8 PAVMs. Depending on the size and localization of the feeding arteries, either Nester-Coils or Amplatzer vascular plugs were used for embolization therapy. cMRI was performed immediately before, and at the 4 h and 3-month post-embolization therapy. Detection of peri-interventional cerebral emboli was performed via T2w and DWI sequences using three different b-values, with calculation of ADC maps. Results Embolization did not show any post-/peri-interventional, newly developed ischemic lesions in the brain. Only one patient who underwent re-embolization and was previously treated with tungsten coils that corroded over time showed newly developed, small, diffuse emboli in the post-interventional DWI sequence. This patient already had several episodes of brain emboli before re-treatment due to the corroded coils, and during treatment, when passing the corroded coils, experienced additional small, clinically inconspicuous brain emboli. However, this complication was anticipated but accepted, since the vessel had to be occluded distally. Conclusion Catheter-based embolization of PAVMs is a safe method for treatment and does not result in clinically inconspicuous cerebral ischemia, which was not demonstrated previously.

[Pulmonary arteriovenous shunt - a rare cause of recurrent stroke due to paradoxical embolism]

Paradoxical embolism is one of the mechanisms of ischemic stroke in patients younger than 45 years of age, due to opening between the right and left chambers of the heart through a patent foramen ovale, an atrial or ventricular septal defect, pulmonary arteriovenous malformations (PAVMs), etc. The PAVMs are structurally abnormal vessels that provide direct capillary-free communication between the pulmonary and systemic circulations, and hence an anatomic "right-to-left" shunt. Most pulmonary malformations are congenital and associated with hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease). This publication highlights the issues of pathogenesis, clinical presentation, diagnosis and treatment of this pathology, and also describes a clinical case in which multiple PAVMs caused repeated ischemic strokes.

Approach to Pulmonary Arteriovenous Malformations: A Comprehensive Update

Pulmonary arteriovenous malformations (PAVMs) are abnormal direct vascular communications between pulmonary arteries and veins which create high-flow right-to-left shunts. They are most frequently congenital, usually in the setting of hereditary hemorrhagic telangiectasia (HHT). PAVMs may be asymptomatic or present with a wide variety of clinical manifestations such as dyspnea, hypoxemia, or chest pain. Even when asymptomatic, presence of PAVMs increases patients' risk of serious, potentially preventable complications including stroke or brain abscess. Transcatheter embolotherapy is considered the gold standard for treatment of PAVMs. Though previous guidelines have been published regarding the management of PAVMs, several aspects of PAVM screening and management remain debated among the experts, suggesting the need for thorough reexamination of the current literature. The authors of this review present an updated approach to the diagnostic workup and management of PAVMs, with an emphasis on areas of controversy, based on the latest literature and our institutional experience.

Arteriovenous fistula creation for hypoxia after single ventricle palliation: A single-institution experience and literature review

BACKGROUND

Hypoxia is a common and sometimes severe morbidity of single ventricle congenital heart disease (CHD). Creation of an arteriovenous fistula (AVF) is occasionally performed for patients after superior or total cavopulmonary connection (SCPC or TCPC) in an attempt to improve oxygen saturations. Despite previous reports, AVF creation is a rare palliation with inadequately defined benefits and risks. We sought to determine changes in peripheral oxygen saturation (SpO₂ ) and risk of adverse event after AVF creation in children with single ventricle CHD at our institution.

METHODS

We conducted a retrospective chart review of patients with a history of single ventricle palliation and history of surgical AVF creation who were seen at our tertiary care center from 1996 to 2017.

RESULTS

A total of seven patients were included in our study. SpO₂ for the overall cohort did not significantly increase after AVF creation (pre-AVF 79.1 ± 6.9%, post-AVF 82.7 ± 6.0% [P = .23]). SpO₂ trended up for large shunts (>5 mm) (pre-AVF 75.0 ± 7.6%, post-AVF 84.0 ± 5.3% [P = .25]). SpO₂ did not improve for small shunts (≤5 mm) (pre-AVF 82.3 ± 6.5%, post-AVF 81.0 ± 8.5% [P = .50]). The 12-month overall and transplant-free survival were 85.7% and 71.4%, respectively. Freedom from AVF-related complication (cephalic edema, thrombotic occlusion) was 51.4% at 12 months.

CONCLUSION

Palliative AVF creation for patients with single ventricle CHD and hypoxia does not universally improve SpO₂ and is prone to early complications. Despite a lack of durable benefit and known risks, AVF creation remains a reasonable palliation for a subset of patients after SCPC who are not candidates for TCPC, or potentially as a bridge to heart transplantation.

Y-graft modification to the Fontan procedure: Increasingly balanced flow over time

OBJECTIVE

The use of Y-grafts for Fontan completion is hypothesized to offer more balanced hepatic flow distribution (HFD) and decreased energy losses. The purpose of this study was to evaluate the hemodynamic performance of Y-grafts over time using serial cardiac magnetic resonance data and to compare their performance with extracardiac Fontan connections.

METHODS

Ten Fontan patients with commercially available Y-graft connections and serial postoperative cardiac magnetic resonance data were included in this study. Patient-specific computational fluid dynamics simulations were used to estimate HFD and energy losses. Y-graft performance was compared with 3 extracardiac conduit Fontan groups (n = 10 for each) whose follow-up times straddle the Y-graft time points.

RESULTS

Y-graft HFD became significantly more balanced over time (deviation from 50% decreased from 18% ± 14% to 8% ± 8%; P = .015). Total cavopulmonary connection resistance did not significantly change. Y-grafts at 3-year follow-up showed more balanced HFD than the extracardiac conduit groups at both the earlier and later follow-up times. Total cavopulmonary connection resistance was not significantly different between any Y-graft or extracardiac conduit group.

CONCLUSIONS

Y-grafts showed significantly more balanced HFD over a 3-year follow-up without an increase in total cavopulmonary connection resistance, and therefore may be a valuable option for Fontan completion. Additional follow-up data at longer follow-up times are still needed to thoroughly characterize the potential advantages of Y-graft use.

Pulmonary arteriovenous malformations leading to hypoxemia in child with primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a rare genetic condition characterized by respiratory tract infections, situs inversus or heterotaxy, and male infertility. Chronic respiratory infections begin in childhood and result in complications such as bronchiectasis. As hypoxemia is often attributed to bronchiectasis, other etiologies for desaturation in this setting are not routinely evaluated. The development of pulmonary arteriovenous malformations (PAVMs) in PCD is not an established association. PAVMs as the etiology for hypoxemia may have been overlooked due to the lack of awareness of this rare association. We present a child with diagnosis of PCD with significant hypoxemia in the absence of bronchiectasis, found to have diffuse bilateral PAVMs and discuss possible physiopathologic mechanisms.

Fontan Revision: Presurgical Planning Using Four-Dimensional (4D) Flow and Three-Dimensional (3D) Printing

Pulmonary arteriovenous malformations (AVMs) can be a complication of certain postoperative Fontan patients whose hepatic venous blood return is not distributed evenly to both lungs. A ten-year-old female, who had previously undergone staged single ventricle palliation for complex congenital heart disease, underwent a Fontan revision due to significant left-sided pulmonary AVMs and increasing arterial oxygen desaturation. The combination of four-dimensional flow cardiac magnetic resonance imaging and three-dimensional printing enabled presurgical planning for a Fontan takedown and diversion of hepatic venous flow to the azygous vein that resulted in significant clinical improvement.

[An Unusual Hemisphere Syndrome]

An Unusual Hemisphere Syndrome Abstract. A patient with known hereditary hemorrhagic telangiectasia presents with transient right arm weakness and dizziness. A transient ischemic attack is diagnosed on clinical and risk factors. In the course of the disease, the patient suffers a convulsive event and fever occurs twice without a clear focus on the infection. The initial skull MRI shows a centroparietal lesion on the left with signs of accompanying edema. Due to this unusual concomitant edema, a neoplastic event must also be considered for differential diagnosis. However, the further examinations show no evidence of neoplasia, but the course MRI of the skull shows the image of septic embolisms with a brain abscess. After neurosurgical remediation and appropriate antibiotic treatment, the clinical course is pleasing. The cause of the septic embolisms was a pulmonary arteriovenous malformation due to hereditary hemorrhagic telangiectasia, which could be coiled without complications.

The first cohort of prospective Fontan surgical planning patients with follow-up data: How accurate is surgical planning?

OBJECTIVE

Fontan surgical planning is an image-based, collaborative effort, which is hypothesized to result in improved patient outcomes. A common motivation for Fontan surgical planning is the progression (or concern for progression) of pulmonary arteriovenous malformations. The purpose of this study was to evaluate the accuracy of surgical planning predictions, specifically hepatic flow distribution (HFD), a known factor in pulmonary arteriovenous malformation progression, and identify methodological improvements needed to increase prediction accuracy.

METHODS

Twelve single-ventricle patients who were enrolled in a surgical planning protocol for Fontan surgery with pre- and postoperative cardiac imaging were included in this study. Computational fluid dynamics were used to compare HFD in the surgical planning prediction and actual postoperative conditions.

RESULTS

Overall, HFD prediction error was 17 ± 13%. This error was similar between surgery types (15 ± 18% and 18 ± 10% for revisions vs Fontan completions respectively; P = .73), but was significantly lower (6 ± 7%; P = .05) for hepatic to azygous shunts. Y-grafts and extracardiac conduits showed a strong correlation between prediction error and discrepancies in graft insertion points (r = 0.99; P < .001). Improving postoperative anatomy prediction significantly reduced overall HFD prediction error to 9 ± 6% (P = .03).

CONCLUSIONS

Although Fontan surgical planning can offer accurate HFD predictions for specific graft types, methodological improvements are needed to increase overall accuracy. Specifically, improving postoperative anatomy prediction was shown to be an important target for future work. Future efforts and refinements to the surgical planning process will benefit from an improved understanding of the current state and will rely heavily on increased follow-up data.

Uptake and radiological findings of screening cerebral magnetic resonance scans in patients with hereditary haemorrhagic telangiectasia

Hereditary haemorrhagic telangiectasia (HHT) results in arteriovenous malformations (AVMs), most commonly in the lungs, liver and brain. Discussion of cerebral vascular malformations is an important element of patient management. The current study objectives were to examine uptake and results of screening cerebral magnetic resonance (MR) scans, excluding symptomatic patients requiring neurological investigations. The remaining non-symptomatic individuals received formal pretest counselling that differed according to family history. For the 603 patients with no neurological symptoms of concern, screening scan uptake was higher after publication of the ARUBA trial. Patients with a family history of cerebral haemorrhage were 4 to 14-fold more likely to have a screening scan than patients with no such family history. For patients without neurological symptoms suggesting cerebral AVMs, none of the 59 screening scans performed at our institution demonstrated a cerebral AVM. Four scans (6.8%) demonstrated small aneurysms. The most common abnormality was cerebral infarction (20/59, 33.9%), predominantly identified in patients with pulmonary AVMs. Of 29 pulmonary AVM patients with no previous history of clinical stroke, 16 (55.2%) had between one and five silent infarcts. For HHT patients with pulmonary AVMs, the most frequently affected sites were the cerebellum (40%) and thalamus (14.3%), and the age-adjusted odds ratio for an infarct was 21.6 (95% confidence intervals 3.7, 126), p = 0.001. We concluded that for cerebral screening programmes in HHT, the findings support informed patient choice incorporating understanding that cerebral AVMs are rare in non-symptomatic HHT patients, but that screening scans commonly detect silent cerebral infarction due to pulmonary AVMs.

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.

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.

Unusual synchronous liver and brain abscesses infected by rare Aerococcus viridians in a patient with pulmonary arteriovenous malformations on FDG PET/CT: A case report and literature review

RATIONALE

Pulmonary arteriovenous malformations (PAVMs) complicated with multiple organ abscesses is an uncommon manifestation. Because of the low incidence of the disease, F-18 fluorodeoxyglucose positron emission tomography with computed tomography (F-FDG PET/CT) imaging studies for PAVMs complicated with multiple organ abscesses are scarce.

PATIENT CONCERNS

We report a case of a 54-year-old man presenting with PAVMs complicated with synchronous multiple organ abscesses founded by F-FDG PET/CT. F-FDG PET/CT revealed tortuous stripes and mass opacities with no significant FDG uptake in the left upper lung lobe. However, hypermetabolic lesions located in the anterior inferior segment of right hepatic lobe [with maximum standardized uptake value (SUVmax) of 10.7], and in the right basal ganglia with SUVmax of 14.1 were found by F-FDG PET/CT.

DIAGNOSES

A diagnosis of synchronous liver and brain abscesses infected by rare Aerococcus viridans was determined by tissue culture.

INTERVENTIONS

Vancomycin was provided intravenously, and oral linezolidate tablets were prescribed for anti-inflammatory treatment for 1 month. Liver and head magnetic resonance imaging was performed during the follow-up.

OUTCOMES

The lesion in the right basal ganglia was reduced, and the lesion in the right liver had disappeared, indicating the lesions were abscesses.

LESSONS

The present case indicated that the possibility of abscesses should be considered with patients with PAVMs, and whole-body F-FDG PET/CT is suggested to identify possible accompanying abscesses in multiple organs for PAVMs patients.

Contemporary Management of Pulmonary Arteriovenous Malformations

Pulmonary arteriovenous malformations (PAVMs) are atypical vascular structures involving a direct connection between the pulmonary arterial and venous circulations. While PAVMs are a relatively uncommon disorder, unmanaged cases are at risk for the development of serious complications including embolization and infection. Since their first description in 1897, PAVMs have been identified and treated in a variety of ways. Advancements in diagnostic methods and operative techniques have allowed for more effective treatment of the disease. Most recently, the use of vascular plug transcatheter embolization has been described as an effective therapeutic procedure in the management of PAVMs. In this report, we present our experience with nine cases of PAVMs treated at the University of Kentucky, including special consideration of an exemplary case that illustrates the typical course of treatment for the disease.

Pulmonary arteriovenous malformations complicated by splenic infarction and abscess

Pulmonary arteriovenous malformation (PAVM) is an abnormal blood vessel connecting a pulmonary artery and a vein, and is accompanied by paradoxical embolism to other organs due to a right-to-left shunt. We report the case of a 66-year-old woman with PAVM complicated by splenic infarction and abscess. Although the PAVM had been detected on a chest image 2 years previously, and she had been advised to have further investigations, she decided not to follow this further at the time. She then visited our hospital complaining of worsening dyspnoea on exertion. Detailed examinations revealed splenic infarction and abscessation due to PAVM. PAVM embolization was performed after antibiotic treatment. It is very rare for PAVM to be complicated by splenic infarction and abscess. Regardless of its size, embolization of a PAVM as soon as possible can reduce not only the risk of central nervous system complications, but also the risk of splenic infarction and abscess.

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.

ACR Appropriateness Criteria Clinically Suspected Pulmonary Arteriovenous Malformation

Pulmonary arteriovenous malformations are often included in the differential diagnosis of common clinical presentations, including hypoxemia, hemoptysis, brain abscesses, and paradoxical stroke, as well as affecting 30% to 50% of patients with hereditary hemorrhagic telangiectasia (HHT). Various imaging studies are used in the diagnostic and screening settings, which have been reviewed by the ACR Appropriateness Criteria Vascular Imaging Panel. Pulmonary arteriovenous malformation screening in patients with HHT is commonly performed with transthoracic echocardiographic bubble study, followed by CT for positive cases. Although transthoracic echocardiographic bubble studies and radionuclide perfusion detect right-to-left shunts, they do not provide all of the information needed for treatment planning and may remain positive after embolization. Pulmonary angiography is appropriate for preintervention planning but not as an initial test. MR angiography has a potential role in younger patients with HHT who may require lifelong surveillance, despite lower spatial resolution compared with CT. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Sarcoidosis with Arteriovenous Malformation in a 15-Year-Old Girl - The Rarest of the Rare

INTRODUCTION

Sarcoidosis is an uncommon multi-system disorder with many possible complications. Arteriovenous malformations (AVMs) are a rare vascular complication of sarcoidosis.

CASE DESCRIPTION

A 15-year-old girl presented to the Pediatric Clinic at AKUH with pulmonary, hepatic, joint, and skin manifestations. Physical examination and investigations pointed toward sarcoidosis, including raised erythrocyte sedimentation rate, angiotensin converting enzyme (ACE), and alanine transaminase (ALT). An incidental finding of pulmonary arteriovenous malformation (PAVM) was noticed on echocardiography. She responded to oral corticosteroids, her ACE and ALT levels improved. There was lack of indication for pulmonary angio-embolization for her PAVM. On a 3-year follow-up, her condition improved and she is clinically well.

DISCUSSION

Pulmonary arteriovenous malformation is an extremely rare complication of sarcoidosis, especially among the pediatric population. Hence, this is the first reported case of its kind. The relation between sarcoidosis and PAVM is difficult to establish; however, there are some theories. This condition may be treated depending on the symptoms. Since our patient did not have any significant symptoms of PAVM, she was treated for the underlying disease, i.e., sarcoidosis.

CONCLUSION

While dealing with patients having multi-system disorders like sarcoidosis, one must be very vigilant so as not to miss out on any complication. Regular follow-up visits should be scheduled to rule out new complications and to monitor the past ones.

Amplatzer vascular plug IV for occlusion of pulmonary arteriovenous malformations in a patient with cryptogenic stroke

Paradoxical embolism resulting in cryptogenic stroke has received much attention recently, with the primary focus on patent foramen ovale (PFO). However, it is essential to be vigilant in the search for other causes of paradoxical embolic events, such as pulmonary arteriovenous malformations (PAVM). We describe successful closure of pulmonary AVM with a St Jude Medical (Plymouth, MN) Amplatzer™ vascular plug IV. The newer AVP-IV devices can be used for successful embolization of tortuous pulmonary AVM in remote locations where use of other traditional devices may be technically challenging.

Pulmonary arteriovenous malformations after the superior cavopulmonary shunt: mechanisms and clinical implications

Children with functional single ventricle heart disease are commonly palliated down a staged clinical pathway toward a Fontan completion procedure (total cavopulmonary connection). The Fontan physiology is fraught with long-term complications associated with lower body systemic venous hypertension, eventually resulting in significant morbidity and mortality. The bidirectional Glenn shunt or superior cavopulmonary connection (SCPC) is commonly the transitional stage in single ventricle surgical management and provides excellent palliation. Some studies have demonstrated lower morbidity and mortality with the SCPC when compared with the Fontan. Unfortunately the durability of the SCPC is significantly limited by the development of pulmonary arteriovenous malformations (PAVMs) which have been commonly attributed to the absence of hepatic venous blood flow and the lack of pulsatile flow to the affected lungs. Abnormal angiogenesis has been suggested as a final common pathway to PAVM development. Understanding these fundamental mechanisms through the investigation of angiogenic pathways associated with the pathogenesis of PAVMs would help to develop medical therapies that could prevent or reverse this complication following SCPC. Such therapies could improve the longevity of the SCPC, potentially eliminate or significantly postpone the Fontan completion with its associated complications, and improve long-term survival in children with single ventricle disease.

Endostatin, an inhibitor of angiogenesis, decreases after bidirectional superior cavopulmonary anastamosis

Pulmonary arteriovenous malformations (PAVMs) are a common source of morbidity after bidirectional superior cavopulmonary anastomosis (Glenn). The diversion of hepatic venous effluent away from the pulmonary circulation after Glenn appears to play a significant role in the pathogenesis of PAVMs. Although the liver is known to produce factors that regulate vascular development, specific hepatic inhibitors of angiogenesis have not been described in the post-Glenn population. Endostatin, produced from its precursor collagen XVIII, is a potent inhibitor of angiogenesis produced by the liver. This study aimed to investigate the hypothesis that endostatin levels decrease in patients after Glenn. Levels of endostatin and its precursor, long-type collagen XVIII, were determined by enzyme-linked immunoassay and immunoprecipitation, respectively, for serum samples from 38 patients undergoing Glenn, total cavopulmonary anastomosis (Fontan), or biventricular repair of cardiac defects. Samples were obtained before surgery and 24 h afterward. In patients undergoing a bidirectional Glenn procedure, endostatin levels decreased after surgery (n = 17; 4.42 vs 3.34 ng/ml; p < 0.001), and long type-collagen XVIII levels increased by 200 % (n = 10; p = 0.0001). However, endostatin levels did not change after surgery in patients undergoing Fontan (n = 13) or biventricular repair (n = 8). In patients undergoing Fontan, long-type collagen XVIII increased by 18 % (p < 0.01), whereas in control subjects, the levels were unchanged. These data suggest that the diversion of hepatic blood flow away from the pulmonary circulation in patients after the Glenn procedure inhibits endostatin production from collagen XVIII, resulting in decreased circulating serum endostatin levels. A decrease in endostatin may promote angiogenesis. The mechanism whereby the pulmonary circulation processes endostatin and its potential role in the pathogenesis of PAVMs warrant further study.

Neurologic manifestation as initial presentation in a case of hereditary haemorrhagic telangiectasia

Hereditary Haemorrhagic Telangiectasia (HHT), or Osler-Weber-Rendu syndrome is an uncommon autosomal dominant multi-organ condition of vascular dysplasias. We describe a 19 year old Indian female who presented with cerebral abscess secondary to paradoxical emboli from pulmonary arteriovenous malformations (PAVMs) associated with HHT. Cerebral, pulmonary, hepatic and gastrointestinal involvement can be life-threatening and it is important to have lifelong follow-ups on these patients.