The multiple dimensions of Platypnea-Orthodeoxia syndrome: A review

Platypnea-Orthodeoxia syndrome (POS) is a rare clinical entity characterized by dyspnea and arterial desaturation while in the upright position. The various pathophysiologic mechanisms leading to POS has puzzled clinicians for years. The hypoxia in POS has been attributed to the mixing of the deoxygenated venous blood with the oxygenated arterial blood via a shunt. The primary mechanisms of POS in these patients can be broadly classified based on intracardiac abnormalities, extracardiac abnormalities and miscellaneous etiologies. A Patent Foramen Ovale (PFO) was the most common reported site of an intracardiac shunt. In addition to PFO, intracardiac shunt leading to POS has been reported from either an Atrial Septal Defect (ASD) or an Atrial Septal Aneurysm (ASA). Most patients with an intracardiac shunt also demonstrated a secondary anatomic or a functional defect. Extracardiac causes of POS included intra-pulmonary arteriovenous malformations and lung parenchymal diseases. A systematic evaluation is necessary to identify the underlying cause and institute an appropriate intervention. We conducted a review of literature and reviewed 239 cases of POS. In this article, we review the etiology and pathophysiology of POS and also summarize the diagnostic algorithms and treatment modalities available for early diagnosis and prompt treatment of patients presenting with symptoms of platypnea and/or orthodeoxia.

Clinical implications of pulmonary shunting on saline contrast echocardiography

Pulmonary right-to-left shunting can be encountered using transthoracic contrast echocardiography (TTCE) with agitated saline. Diseases associated with pulmonary shunting on saline TTCE include hereditary hemorrhagic telangiectasia (HHT), hepatopulmonary syndrome, and some congenital heart defects after partial or complete cavopulmonary anastomosis. Furthermore, small pulmonary shunts on saline TTCE are also documented in a proportion of healthy individuals. Pulmonary shunting carries the risk for severe neurologic complications due to paradoxical embolization. In HHT, additional chest computed tomography is recommended in case of any pulmonary shunt detected on saline TTCE, to evaluate the feasibility for transcatheter embolotherapy of pulmonary arteriovenous malformations. Furthermore, antibiotic prophylaxis is advised in case of any pulmonary shunt on saline TTCE to prevent brain abscesses after procedures with risk for bacteremia. The present review provides an overview of important aspects of pulmonary shunting and its detection using saline TTCE. Furthermore, advances in understanding the clinical implications of different pulmonary shunt grades on saline TTCE are described. It appears that small pulmonary shunts on saline TTCE (grade 1) lack any clinical implication, as these shunts cannot be used as a diagnostic criterion for HHT, are not associated with an increased risk for neurologic complications, and represent pulmonary arteriovenous malformations too small for subsequent endovascular treatment. This implies that additional chest computed tomography could be safely withheld in all persons with only small pulmonary shunts on saline TTCE and sets the stage for further discussion about the need for antibiotic prophylaxis in these subjects. Besides further optimization of the current screening algorithm for the detection of pulmonary arteriovenous malformations in HHT, these observations can be of additional clinical importance in other diseases associated with pulmonary shunting and in those healthy individuals with documented small pulmonary shunts on saline TTCE.

Management of pulmonary arteriovenous malformations

Pulmonary arteriovenous malformations are rare lesions with significant clinical complications. These lesions are commonly seen in patients with hereditary hemorrhagic telangiectasia (formerly Osler-Weber-Rendu syndrome). Interventional radiologists are a key part of the treatment team in this complex disease, and a thorough understanding of the disease process is critical to providing good patient care. In this article, the authors review the disease course and its association with hereditary hemorrhagic telangiectasia, discusses the clinical evaluation and treatment of these complex patients, and outlines complications and follow-up.

MVP™ Micro Vascular Plug Systems for the Treatment of Pulmonary Arteriovenous Malformations

PURPOSE

To describe our institutional experience with MVP™ micro vascular plug systems for the treatment of pulmonary arteriovenous malformations (PAVMs).

MATERIALS AND METHODS

We performed a retrospective medical record review of 52 patients with 119 PAVMs treated exclusively with MVP™ systems (69 procedures/153 MVP™ systems) between July 2014 and July 2018. All patients had PAVMs with feeding artery diameters ≥ 2 mm. MVP™ systems were deployed according to physician preference. We collected patient demographic information; procedural data (including size of feeding artery, size and number of embolics used per PAVM, fluoroscopy time, contrast administration), technical success rates, complications, and persistence. Persistence was assessed using computed tomography angiography (CTA) performed 1-3 months and 3-5 years after embolization per clinical protocol.

RESULTS

All procedures were technically successful without major complications. Mean feeding artery diameter was 3.3 ± 1.2 mm. Mean fluoroscopy time per procedure and contrast volume administered per procedure were 35 ± 16 min and 217 ± 101 mL, respectively. A mean of 1.3 ± 0.8 MVP™ systems was used per PAVM. There were no instances of persistence during a mean follow-up time of 328 ± 258 days (range 26 to 914 days).

CONCLUSIONS

For PAVMs with feeding artery diameters of 2 to 7.9 mm (mean 3.3 ± 1.2 mm), MVP™ systems are safe and effective given their high technical success rates and lack of persistence. Further prospective work will be required to elucidate the advantages and disadvantages of these MVP™ systems for PAVM embolization.

LEVEL OF EVIDENCE

Level III.

Usefulness of Hydrogel-Coated Coils in Embolization of Pulmonary Arteriovenous Malformations

Purpose

To evaluate the usefulness of hydrogel-coated coils for preventing recanalization after coil embolization of pulmonary arteriovenous malformations (PAVMs).

Materials and Methods

Thirty-seven consecutive patients with 57 untreated PAVMs underwent coil embolization with hydrogel-coated coils between January 2013 and Jun 2017. The mean age was 49 years (range 9–83 years), and there were seven male patients and 30 female patients. The median size of the feeding artery was 3.7 mm (range 1.5–6.1 mm), and the median size of the venous sac was 9.3 mm (range 2.6–36.6 mm). For all PAVM, embolization was attempted using 0.018-in. hydrogel-coated coils with or without other coils (0.0135–0.018-in. bare platinum coils and fibered platinum coils). Technical success rate, recanalization rate, and complications were evaluated. Technical success was defined as completion of embolization using hydrogel-coated coils. Recanalization was evaluated with time-resolved magnetic resonance angiography and/or pulmonary angiography.

Results

In 56 of 57 PAVMs, embolization was successfully performed with hydrogel-coated coils. Therefore, the technical success rate was 98% (56/57). The number of PAVMs at risk was 56, 42, 18, and 12 at 0, 12, 24, and 36 months, respectively. There was no recanalization with a mean follow-up period of 19 months (range 2–47 months) in 56 PAVMs embolized with hydrogel-coated coils. There were no major complications. As a minor complication, local pain was observed in 8 of 43 sessions (19%) after embolization.

Conclusions

Hydrogel-coated coils may be useful for preventing recanalization after the embolization of PAVMs.

Pulmonary vascular diseases

Pulmonary vascular diseases encompass a large and diverse group of underlying pathologies ranging from venous thromboembolism to congenital malformations to inflammatory vasculitides. As a result, patients can present either acutely with dyspnea and chest pain or chronically with dyspnea on exertion, hypoxia, and right heart failure. Imaging, particularly with multidetector CT, plays a key role in the evaluation and management of patients with suspected pulmonary vascular disease and, given the widespread routine use of high-quality CT pulmonary angiography, it is imperative that radiologists be familiar these pathologies.

Pulmonary arteriovenous malformations: what the interventional radiologist needs to know

Pulmonary arteriovenous malformations (PAVMs) or fistulas are rare direct pathological connections between pulmonary arterial and venous circulation. Most of PAVMs are congenital and closely associated with hereditary hemorrhagic telangiectasia, but acquired PAVMs have also been described in the literature. Diagnosis of PAVMs is a priority for clinicians, in order to prevent potentially fatal events such as cerebrovascular stroke, systemic septic embolization, hemoptysis and hemothorax. In this scenario, the radiologist plays a key role in both diagnostic and therapeutic workups of PAVMs: Chest X-ray, computed tomography and magnetic resonance are effective tools for PAVMs identification and confirmation of the suspected diagnosis. Furthermore, imaging modalities provide most of the elements for PAVMs classification according to their angioarchitecture (simple and complex) and help the clinicians in establishing which lesion requires prompt treatment and which one will benefit of imaging follow-up alone. Endovascular management of PAVMs has grown up as the first-line treatment in respect of surgery during last decades, showing lower risk of intra- and post-procedural complications and offering a wide number of treatment options and materials, ensuring effective management in virtually any clinical situation; interventional treatment aims to exclude PAVMs from pulmonary circulation, and specific technique and embolic agents should be selected according to pre-treatment imaging, in order to obtain the best procedural outcome. This paper proposes a review of the clinical and radiological features that a radiologist needs to know for PAVMs diagnosis and proper management, also showing an overview of the most common endovascular treatment strategies and embolization materials.

Evaluation of percutaneous transcatheter embolization for pulmonary arteriovenous malformations

BACKGROUND

The purpose of this study was to assess the safety and efficacy of percutaneous transcatheter embolization (TCE) for the treatment of pulmonary arteriovenous malformations (PAVMs).

METHODS

Forty-three consecutive patients (n = 17 males; n = 26 females) with 72 untreated PAVMs underwent coil and/or plug embolization between January 2010 and February 2018. The mean patient age was 42 ± 14 years (range 19-71 years). The median size of the feeding artery was 7.9 ± 2.9 mm (range 3.5-14.0 mm). The arterial blood gas level and cardiac function of all patients were analysed. The technical success rate, recanalization rate, and complications were evaluated. Computed tomography angiography (CTA) examinations were scheduled for 12 months after treatment and every 2-4 years thereafter.

RESULTS

Twenty-five PAVMs were treated with coils alone, twenty-one were treated with plugs alone, and twenty-six were treated with both coils and plugs. The technical success rate was 100%. There were no complications during operation. However, one patient (2.3%) had pulmonary thrombosis and embolism post-operation. The patients' pre-operative and post-operative PaO₂ and SaO₂ levels were significantly different (p < 0.01). A comparison of the New York Heart Association (NYHA) grade before and after embolization in all patients showed a significant decrease in the post-operative grade (p < 0.01). The 72 PAVMs were divided into three groups (coils only group [n = 25], plugs only group [n = 21], and coils/plugs combined group [n = 26]). After 12 months of follow-up, there were seven reperfusion PAVMs in the coil group, seven reperfusion PAVMs in the plug group, and 1 reperfusion PAVM in the combined group. There were significant differences between the two groups and the combined group.

CONCLUSION

Percutaneous TCE is safe and effective for the treatment of PAVMs. A combination of coils and vascular plugs may be useful for preventing recanalization after the embolization of PAVMs.

Pulmonary arteriovenous malformations and embolic complications in patients with hereditary hemorrhagic telangiectasia

Patients with hereditary hemorrhagic telangiectasia (HHT) and pulmonary arteriovenous malformation (PAVM) face higher risk of embolic complications. It is not clear whether poor outcomes are related to PAVM severity or pulmonary symptoms. Furthermore, there is currently no available data on HHT patients in Argentina. We conducted a cross sectional study in a teaching hospital in Buenos Aires, Argentina. We describe baseline characteristics of HHT and compare the prevalence of embolic complications in patients with significant PAVM compared to patients without significant PAVM. One hundred and eight consecutive patients were included. Significant PAVM was defined as: contrast echocardiography grade 2 or greater; bilateral PAVM or feeding artery bigger than 3mm; or previous PAVM treatment. Primary composite outcome was defined as: cerebrovascular accident, cerebral abscess or peripheral embolism. 20% of participants had embolic complications, the most frequent one was stroke. Embolic complications were associated with significant PAVM and respiratory symptoms.

Giant high-flow type pulmonary arteriovenous malformation: coil embolization with flow control by balloon occlusion and an anchored detachable coil

Pulmonary arteriovenous malformations (PAVMs) are often treated by pushable fibered or non-fibered microcoils, using an anchor or scaffold technique or with an Amplatzer plug through a guiding sheath. When performing percutaneous transcatheter microcoil embolization, there is a risk of coil migration, particularly with high-flow type PAVMs. The authors report on a unique treatment in a patient with a giant high-flow PAVM whose nidus had a maximum diameter of 6 cm. A detachable coil, not detached from a delivery wire (an anchored detachable coil), was first placed in the feeding artery under flow control by balloon occlusion, and then multiple microcoils were packed proximally to the anchored detachable coil. After confirming the stability of the microcoils during a gradual deflation of the balloon, we finally released the first detachable coil. The nidus was reduced in size to 15 mm at one year postoperatively.

Utility of second-generation single-energy metal artifact reduction in helical lung computed tomography for patients with pulmonary arteriovenous malformation after coil embolization

PURPOSE

The quality of images acquired using single-energy metal artifact reduction (SEMAR) on helical lung computed tomography (CT) in patients with pulmonary arteriovenous malformation (PAVM) after coil embolization was retrospectively evaluated.

MATERIALS AND METHODS

CT images were reconstructed with and without SEMAR. Twenty-seven lesions [20 patients (2 males, 18 females), mean age 61.2 ± 11.0 years; number of embolization coils, 9.8 ± 5.0] on contrast-enhanced CT and 18 lesions of non-enhanced lung CT concurrently performed were evaluated. Regions of interest were positioned around the coils and mean standard deviation value was compared as noise index. Two radiologists visually evaluated metallic coil artifacts using a four-point scale: 4 = minimal; 3 = mild; 2 = strong; 1 = extensive.

RESULTS

Noise index was significantly improved with SEMAR versus without SEMAR (median [interquartile range]; 194.4 [161.6-211.9] Hounsfield units [HU] vs. 243.9 [220.4-286.0] HU; p < 0.001). Visual score was significantly improved with SEMAR versus without SEMAR (Reader 1, 3 [3] vs.1 [1]; Reader 2, 3 [3] vs.1 [1]; p < 0.001). Significant differences were similarly demonstrated on lung CT (p < 0.001).

CONCLUSION

SEMAR provided clear chest CT images in patients who underwent PAVM coil embolization.

Embolotherapy for pulmonary arteriovenous malformations in patients without hereditary hemorrhagic telangiectasia

Objective

To evaluate the clinical and radiological outcomes of transcatheter embolotherapy for treating sporadic pulmonary arteriovenous malformations (PAVMs) that were not associated with hereditary hemorrhagic telangiectasia.

Materials and Methods

Between January 2001 and June 2008, thirty-five sporadic PAVMs were detected in 23 patients. The clinical follow up consisted of assessing the changes of the signs and symptoms of the PAVMs, and radiological evaluation with chest radiographs or chest CT scans.

Results

The lower lung regions (63%) and peripheral locations (86%) were the common locations of the PAVMs. Thirty-four PAVMs (97%) had simple architecture (one arterial feeder within a single pulmonary segment). Technical success was achieved in 33 PAVMs (94%); two cases of technical failure were due to catheterization failure (n = 1) and too large a feeding artery (17 mm) that disabled embolotherapy (n = 1). Coils and Amplatz vascular plugs were used in 30 and three PAVMs, respectively. Inadvertent placement of one coil (n = 1) and pulmonary infarction (n = 1) occurred, but no relevant symptoms developed. For the 13 patients with available data, the mean arterial O₂ saturation changed significantly from 92% to 98%. Complete or near-complete involution of the sac was observed in 30 of the 33 embolized PAVMs (91%). In these 33 embolized PAVMs, the mean sac diameter significantly decreased from 17.83 mm to 0.68 mm.

Conclusion

Sporadic PAVMs are mostly the simple type with predominance in the lower lobe and peripheral locations. Transcatheter embolotherapy with coils or Amplatz vascular plugs is a safe and effective treatment for sporadic PAVMs and this provides excellent functional and radiological improvement.

BMPR2 gene mutation in pulmonary arteriovenous malformation and pulmonary hypertension: a case report

The transforming growth factor-β superfamily signaling pathway is thought to be involved in the pathogenesis of pulmonary arteriovenous malformation (PAVM). However, the association between bone morphogenetic protein receptor type 2 (BMPR2) gene mutations and PAVM remains unclear. We present a case of concurrent PAVM and pulmonary arterial hypertension (PAH), with a deletion mutation in exon 6 and exon 7 of the BMPR2 gene. Drug treatment for PAH improved the patient's hemodynamics and exercise capacity, but worsened oxygenation. This case suggests that BMPR2 gene mutation may be associated with the complex presentation of PAVM combined with PAH.

Effect of pulmonary arteriovenous malformations on the mechanical properties of the lungs

BACKGROUND

Pulmonary arteriovenous malformations (PAVMs) are present in approximately 15-50% individuals with hereditary hemorrhagic telangiectasia (HHT). They may be isolated but more often are multiple. The goal of this study was to evaluate the influence of PAVMs on lung mechanical properties.

METHODS

We reviewed the files of all adult patients (age ≥ 18 years) referred to our Center for evaluation of HHT between 2005 and 2013. The diagnosis of HHT was based on the Curacao criteria and/or the presence of a pathogenic mutation. Exclusion criteria included: chronic cardiac or lung disease (i.e. asthma or COPD), suspicion of pulmonary hypertension on echocardiography, current or past smoking (>10 pack-years), history of thoracic surgery, previous treatment of PAVMs by embolotherapy, lung infection or thromboembolic disease in the past 3 months, pregnancy and obesity (BMI > 30 kg/m²). Chest high resolution CT-scan and pulmonary function tests were performed the same day in all patients as part of our routine work-up.

RESULTS

One hundred and fifty five patients with HHT were included (age: 44.4 ± 16.7 yrs - mean ± SD -; males: 39%). Eighty eight patients had no PAVM, 45 had 1-3 PAVMS and 22 had at least 4 PAVMs. Thirty eight patients had unilateral PAVMs and 29 bilateral PAVMs. We found no statistical relationship between the number, the size and the laterality of PAVMs and results of lung flows and volumes.

CONCLUSION

We found no evidence that PAVMs have a significant influence on lung mechanical properties as measured using routine pulmonary function tests in adult patients with HHT, even in case of numerous, macroscopic or bilateral malformations.

Treatment of pulmonary arteriovenous malformations: clinical experience using different embolization strategies

PURPOSE

To evaluate embolization efficacy of pulmonary arteriovenous malformations (PAVM) using Amplatzer vascular plugs (AVP) and coils.

MATERIALS AND METHODS

Eighty-eight embolized simple PAVMs in 38 patients were retrospectively analyzed by follow-up CT. Mean age was 50.2 ± 15.6 years and 22 (57.9%) patients were females. Mean follow-up interval was 38.2 ± 28.4 months (median 29.9 months). Embolization devices included AVP I, AVP II, AVP 4, and coils. Technical success was defined as no visualization of an early draining vein at angiography after embolization. Treatment success was defined as complete disappearance or decrease in size of the venous aneurysm ≥ 70% at follow-up CT.

RESULTS

Technical success rate was 100% and treatment success rate evaluated by CT for the various embolization strategies was 100% for AVP I (n = 6), 100% for AVP I + coils (n = 5), 83.3% for AVP II (n = 6), 40.0% for AVP II + coils (n = 5), 87.5% for AVP 4 (n = 8), 50.0% for AVP 4 + coils (n = 8), and 78.0% for coils alone (n = 50). No statistically significant difference in embolization efficacy was seen between different devices (P = 0.083). Although not statistically significant, combination use of coils with AVPs demonstrated lower rates of clinical embolization success (P = 0.053).

CONCLUSION

Embolization of PAVMs demonstrated high technical and treatment success rates with available embolic devices. No significant statistical differences were demonstrated between AVPs. However, the need for both coils and AVPs may suggest a more complicated underlying lesion at risk for recurrence.

Pulmonary arteriovenous malformation as a cause of embolic stroke: case report and review of the literature

BACKGROUND

Pulmonary arteriovenous malformation (PAVM) is an abnormal communication between pulmonary arteries and veins responsible for right-to-left shunting that could induce the development of embolic stroke.

SUMMARY

We describe an 82-year-old woman without history of respiratory or neurological diseases, who presented at our observation unit with acute onset of cerebral ischemia. Clinical, laboratory and radiological findings diagnosed a PAVM.

KEY MESSAGES

Usually, endovascular procedures based on embolization or, alternatively, surgery represent the recommended treatment. However, both hormonal therapy and thrombolytic therapy can be used. In our patient, treatment with warfarin induced a remission of symptoms. This strategy should be tested in larger studies.

Pulmonary arteriovenous malformation (PAVM) embolization: prediction of angiographically-confirmed recanalization according to PAVM Diameter changes on CT

Background

To assess pulmonary arteriovenous malformation (PAVM) recanalization after embolization based on PAVM diameter changes on computed tomography (CT), with pulmonary angiography used as a gold standard.

Methods

A retrospective review was done of patients from 2008 to 2019 with a PAVM treated with endovascular embolization. The treatment outcome was determined by conventional angiography. Follow-up pulmonary angiography was performed when recanalization was suspected on CT, or embolization of all lesions in multiple PAVM patients could not be completed in a single session. Patients who had no preprocedural or follow-up CT were excluded. Draining vein, feeding artery, and venous sac diameter were measured on CT, and diameter reduction rates were compared with the widely-used, binary 70 % criteria.

Results

Forty-one patients with 114 PAVMs were treated during the study period. Eight patients with 50 PAVMs met the inclusion criteria. Mean vein, artery, and venous sac diameter reduction rates were as follows: 59.2 ± 9.3 %, 47.5 ± 10.6 %, and 62.6 ± 13.2 %, respectively, in the occluded group and 5.4 ± 19.5 %, 11.3 ± 17.7 %, and 26.8 ± 14.2 %, respectively, in the recanalized group. The area under the receiver operating characteristic curves for PAVM recanalization for the draining vein was 1.00, showing a better result than the artery (0.97) and sac (0.99). Patients showed > 42 % draining vein diameter reduction in the occluded group and < 32 % in the recanalized group. The widely-used 70 % criteria showed low specificity for predicting recanalization (draining vein, 7.3 %; venous sac, 41.7 %) but 100 % sensitivity for both the draining vein and venous sac.

Conclusions

The widely-used 70 % binary criteria showed limited performance in predicting outcomes in this angiographically-confirmed case series. Further investigations are warranted to establish a strategy for detecting recanalization after PAVM embolization.

Management of a solitary pulmonary arteriovenous malformation by video-assisted thoracoscopic surgery and anatomic lingula resection: video and review

BACKGROUND

Pulmonary arteriovenous malformations are abnormal communications between the pulmonary arterial and venous vasculature leading to a right-to-left blood shunt. Based on possible complications, including hypoxemia, hemorrhage, infection and paradoxical embolism, deactivation of the malformation from the circulation is the treatment option of choice, either by interventional embolization or by surgery. Embolization is less invasive and has widely replaced surgery, but bears the risk of revascularization, recanalization and downstream migration of the device with paradoxical embolism.

METHODS

We report on the case of a 76-year-old male patient suffering from a complex, plexiform pulmonary arteriovenous malformation in the lingula, which was treated by video-assisted thoracoscopic surgery and anatomic lingula resection. Patient's medical history, clinical examination and imaging studies did not reveal any evidence of hereditary hemorrhagic telangiectasia.

RESULTS

Left-sided anterior three-port video-assisted thoracoscopic surgery (VATS) approach was used. Instead of only wedge resecting the very peripherally located pulmonary arteriovenous malformation, the lingular vessels were controlled centrally and an anatomic lingula resection was performed in order to prevent a more central re-malformation. To prevent rupture of the aneurysm sac through pressure overload, the feeding arteries were controlled before the draining vein. Duration of the total procedure was 151 min, the single chest tube was removed on the postoperative day 3, and the patient was discharged on the postoperative day 6.

CONCLUSION

Although interventional embolism of the feeding artery of a pulmonary arteriovenous malformation is the current therapeutic gold standard, minimally invasive anatomic lung resection by video-assisted thoracoscopic surgery can be considered, especially for the treatment of solitary large arteriovenous malformations. By anatomic lung resection, the risk of recanalization, collateralization and peri-interventional paradoxical embolism may be reduced.

Pulmonary arteriovenous malformation in a neonate: a condition commonly misdiagnosed

Pulmonary arteriovenous malformations (PAVMs) are congenital defects in the form of an anomalous bridging between a pulmonary arterial and venous system that sidesteps the normal pulmonary capillary. This anomaly is usually associated with hereditary hemorrhagic telangiectasia, leftover small group are sporadic cases but may occur as an isolated anomaly or as multiple lesions. Rarely, such abnormalities can be acquired. Few cases are diagnosed in the neonatal period, as it will pass silent without symptoms. Clinical manifestations occur soon after birth as cyanosis, tachypnea, and an abnormal sound as bruit over the AVM; and the most important point is the clinical suspicion of diagnosis in absence of pulmonary parenchymal and cardiac disease that can explain the persistence of cyanosis. We report a successful Amplatzer vascular plug occlusion of isolated multiple left side PAVM in a neonate, which was done on two stages with a 6 months interval, with no complications. Over 2-year follow-up, the patient remained well with no symptoms.

Ultra-short echo time magnetic resonance imaging for detection of pulmonary arteriovenous malformation recanalization after coil embolization: a case report and a phantom study

A pulmonary arteriovenous malformation (PAVM) is a direct connection between the pulmonary arteries and veins for which metallic coil transcatheter embolization is the standard of care. Detecting recanalization after PAVM treatment is crucial, but direct visualization with computed tomography or magnetic resonance imaging (MRI) is generally difficult. Here, we report a case of a recanalized PAVM that was directly detected with ultra-short echo time MRI. The detection of these signals in the coils was confirmed in a phantom study.

Pulmonary venous anomalies causing misdiagnosis of pulmonary arteriovenous malformations

PURPOSE

To investigate pulmonary venous anomaly as a cause of pulmonary arteriovenous malformation (PAVM) misdiagnosis.

MATERIALS AND METHODS

We reviewed adult patients within a 7.5-year period with CT scans initially diagnosed with PAVM and subsequent conventional pulmonary angiograms.

RESULTS

Pulmonary arteriography showed no PAVM on arterial phase for 10 out of 99 patients, comprising the misdiagnosed group. Four misdiagnosed patients had pulmonary venous anomalies and six had nodular lesions on CT.

CONCLUSION

Pulmonary venous anomalies are vascular mimics of PAVMs that may lead to misdiagnosis. Optimal CT technique and careful imaging review are necessary to minimize inappropriate invasive angiography.

Reproducibility of right-to-left shunt quantification using transthoracic contrast echocardiography in hereditary haemorrhagic telangiectasia

Aim

Transthoracic contrast echocardiography (TTCE) is recommended for screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia. Shunt quantification is used to find treatable PAVMs. So far, there has been no study investigating the reproducibility of this diagnostic test. Therefore, this study aimed to describe inter-observer and inter-injection variability of TTCE.

Methods

We conducted a prospective single centre study. We included all consecutive persons screened for presence of PAVMs in association with hereditary haemorrhagic telangiectasia in 2015. The videos of two contrast injections per patient were divided and reviewed by two cardiologists blinded for patient data. Pulmonary right-to-left shunts were graded using a three-grade scale. Inter-observer and inter-injection agreement was calculated with κ statistics for the presence and grade of pulmonary right-to-left shunts.

Results

We included 107 persons (accounting for 214 injections) (49.5% male, mean age 45.0 ± 16.6 years). A pulmonary right-to-left shunt was present in 136 (63.6%) and 131 (61.2%) injections for observer 1 and 2, respectively. Inter-injection agreement for the presence of pulmonary right-to-left shunts was 0.96 (95% confidence interval (CI) 0.9–1.0) and 0.98 (95% CI 0.94–1.00) for observer 1 and 2, respectively. Inter-injection agreement for pulmonary right-to-left shunt grade was 0.96 (95% CI 0.93–0.99) and 0.95 (95% CI 0.92–0.98) respectively. There was disagreement in right-to-left shunt grade between the contrast injections in 11 patients (10.3%). Inter-observer variability for presence and grade of the pulmonary right-to-left shunt was 0.95 (95% CI 0.91–0.99) and 0.97 (95% CI 0.95–0.99) respectively.

Conclusion

TTCE has an excellent inter-injection and inter-observer agreement for both the presence and grade of pulmonary right-to-left shunts.

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1094-4) contains supplementary material, which is available to authorized users.

Massive haemorrhagic complications of ruptured pulmonary arteriovenous malformations: outcomes from a 12 years' retrospective study

Background

The life-threatening haemorrhagic complications of pulmonary arteriovenous malformations (PAVMs) are extremely rare, and only described in isolated cases. This study was designed to comprehensively investigate management of ruptured PAVMs.

Methods

We retrospectively assessed clinical and imaging data of ruptured PAVMs to summarize incidence, clinical characteristics, and outcomes following embolisation between January 2008 and January 2021.

Results

Eighteen of 406 (4.4%) patients with PAVMs developed haemorrhagic complications. Twelve of 18 patients were clinically diagnosed with hereditary haemorrhagic telangiectasia (HHT). Haemorrhagic complications occurred with no clear trigger in all cases. Eight of 18 patients (44.4%) were initially misdiagnosed or had undergone early ineffective treatment. 28 lesions were detected, with 89.3% of them located in peripheral lung. Computed tomography angiography (CTA) showed indirect signs to indicate ruptured PAVMs in all cases. Lower haemoglobin concentrations were associated with the diameter of afferent arteries in the ruptured lesions. Successful embolotherapy was achieved in all cases. After embolotherapy, arterial oxygen saturation improved and bleeding was controlled (P < 0.05). The mean follow-up time was 3.2 ± 2.5 years (range, 7 months to 10 years).

Conclusions

Life threatening haemorrhagic complications of PAVMs are rare, they usually occur without a trigger and can be easily misdiagnosed. HHT and larger size of afferent arteries are major risk factors of these complications. CTA is a useful tool for diagnosis and therapeutic guidance for ruptured PAVMs. Embolotherapy is an effective therapy for this life-threatening complication.

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.

Surgical lobectomy of pulmonary arteriovenous malformations in a patient with presentations regarded as sequela of tuberculosis: a case report

Background

Pulmonary arteriovenous malformations are uncommon conditions of abnormal communications between pulmonary arteries and veins, which are most commonly congenital in nature. Although such condition is not extremely rare, it is a challenge to the differential diagnosis of pulmonary problems such as hypoxemia and pulmonary lesions.

Case presentation

We report a meaningful case of a 23-year-old male presented with elevated hemoglobin (23.0 g/dl) on admission. Physical examination revealed cyanosis, digital clubbing and low oxygen saturation on room air. The patient was initially diagnosed as polycythemia vera while the subsequent result of bone marrow aspiration was negative. During further assessment, pulmonary arteriovenous malformations were detected by CT pulmonary angiography. Lobectomy was successfully performed with significant increase in oxygen saturation from 86 to 98%. The hemoglobin decreased to almost normal level of 14.9 g/dl 3 months after surgery and the patient had been followed up for nearly 5 years.

Conclusions

Pulmonary arteriovenous malformations should be suspected in patients with central cyanosis, digital clubbing, polycythemia, pulmonary lesion and without cardiac malformations. Embolization or surgery is strongly recommended to reduce the risks caused by pulmonary arteriovenous malformations.