Treatment Of Pulmonary Arteriovenous Malformations Research Articles

An Alternative Endovascular Technique for Treatment of Pulmonary Arteriovenous Malformation: Microballoon-occluded Transcatheter Embolization Using n-butyl-2-cyanoacrylate.

To investigate the safety and efficacy of microballoon-occluded transcatheter embolization using n-butyl-2-cyanoacrylate (NBCA) in patients with a single pulmonary arteriovenous malformation (PAVM). From November 2017 to November 2020, this retrospective study included 38 previously untreated patients with a single PAVM who underwent microballoon-occluded transcatheter embolization using NBCA. All 38 patients had follow-up that included simple chest radiography and contrast-enhanced chest computed tomography (CT). A microballoon was successfully placed in a feeding artery of the PAVM to control the delivery of the NBCA cast in all 38 patients, with complete embolization of sacs and the feeding artery achieved in all cases. The mean diameters of the feeding artery, sac, and draining vein were 3.9 ± 0.9mm, 7.5 ± 2.6mm, and 4.6 ± 1.3mm, respectively. A fixed 1:2 NBCA/Lipiodol ratio was used, and the mean amount of embolic mixture per patient was 1.4mL (range 0.6-2.2mL). There were no complications related to microballoon adhesion and non-target embolization of the systemic circulation. Follow-up CT in all 38 patients with a mean delay of 34.5 ± 8.8months (range 20.7-56.5months) showed no continued perfusion of the PAVM. In our hands, microballoon-occluded n-butyl-2-cyanoacrylate embolization seemed to be safe and appeared to be clinically effective in patients with simple and complex types of single PAVM. Therefore, the present technique has the potential to become a standard treatment for a single PAVM.

Pulmonary AVM Embolization

Pulmonary arteriovenous malformations (PAVMs) are rare fistulous connections between pulmonary arteries and veins that, as in our case, are commonly associated with hereditary hemorrhagic telangiectasia (HHT). Embolotherapy, the mainstay of treatment for PAVMs, is a procedure in which the feeding arteries of a malformation are endovascularly occluded under fluoroscopic guidance. Effective and well-tolerated, embolotherapy has been shown to decrease right-to-left shunting following treatment and decrease risks of paradoxical embolization and lung hemorrhage and to improve pulmonary gas exchange and lung function. Patients are selected for treatment according to clinical suspicion for the presence of a PAVM and feeding artery diameter. The occlusion of PAVMs with arteries that exceed 2-3 mm in diameter is recommended. Diagnostic contrast-enhanced pulmonary angiography is performed via injection of contrast through a percutaneous catheter to characterize and confirm PAVMs suitable for embolization. Lesions are then treated by catheter-directed placement of embolic material— vascular plugs in our case—into the feeding artery, terminating blood flow to the area of the lesion. Although multiple PAVMs may be embolized during a single session, in patients with HHT, who may present with large numbers of PAVMs, treatment is limited by maximum contrast dosage, and additional sessions may be performed if PAVMs remain perfused.

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

To evaluate the safety, technical success and short-term effectiveness of polyurethane-covered stent (PK Papyrus, BioTronik, Berlin) in the treatment of pulmonary arteriovenous malformations (PAVMs) that are not amenable to embolotherapy. In this IRB-approved, retrospective study, data from patients who received polyurethane-covered stents for exclusion of PAVMs were analyzed. The study included 5 patients (all women) with a median age of 40years (range 25-60). Patients presented with hypoxemia, TIAs, and/or epistaxis; 4 were confirmed to have HHT. All had multiple PAVMs diagnosed on chest CT and underwent embolization with other devices in addition to the polyurethane-covered stent. The indication for stent placement in all cases was a short and/or tortuous feeding artery. Safety was assessed by immediate or short-term complications, e.g., migration, stent thrombosis, and fracture. Technical success was defined as the ability to accurately place the stent at the intended location. Effectiveness was defined as successful exclusion of PAVM with no perfusion across the AVM. Technical success of stent placement was 100%. AVM exclusion rate was 80% after single stent deployment; in the case of incomplete exclusion, success was achieved using an overlapping stent to completely cover a second feeding artery. During the median follow-up period of 5months (range 2-10), all stents remained patent, and AVMs were excluded without other complications. Exclusion of PAVMs with polyurethane-covered stents is technically feasible, safe, and shows short-term effectiveness for PAVMs with a short/tortuous feeding artery when traditional embolization techniques are not possible.

Transarterial Embolization of Simple Pulmonary Arteriovenous Malformations: Long-Term Outcomes of 0.018-Inch Coils versus Vascular Plugs

PurposeTo compare the safety, effectiveness, and persistence rates of 0.018-inch coils with those of Amplatzer vascular plugs (AVPs; Abbott Vascular, Abbott Park, Illinois) for the treatment of pulmonary arteriovenous malformations (PAVMs) in response to a growing concern that 0.018-inch coil embolization would increase the long-term persistence rate. Materials and MethodsThis is a retrospective, single-center study of a database (2002–2020) of 633 PAVM embolizations. Complex PAVMs and those not embolized with 0.018-inch coils or plugs were excluded. PAVM embolization material was classified into 4 groups: (a) 0.018-inch nonfibered coils (NFCs), (b) 0.018-inch fibered coils (FCs), (c) NFCs and FCs, or (d) plugs. Persistence was defined as flow through the PAVM on digital subtraction angiography (DSA) or as <30% diameter reduction of the aneurysmal sac on unenhanced computed tomography (CT). Kaplan–Meier analysis and Cox regression were used to assess PAVM’s persistence-free survival. ResultsA total of 312 PAVM embolizations with NFCs (43 PAVMs), FCs (127 PAVMs), NFCs and FCs (12 PAVMs), or plugs (130 PAVMs) in 109 patients (28% men; mean age = 49 years) were included. All PAVM embolizations were technically successful without any major adverse events. PAVM persistence-free survival rates at 10 years’ follow-up were 40.8% versus 44.7% in the NFC and FC groups (P = .22) and 47.3% versus 81.0% in the 0.018-inch coil (NFC or FC) and plug groups (P < .0001), respectively. There were 0.43 (79/182) and 0.08 (10/130) re-embolization procedures per PAVM in the 0.018-inch coil and plug groups, respectively (P < .001). ConclusionsPAVM embolization with 0.018-inch coils was safe, but persistence rate with PAVM embolization was significantly higher than that with plugs, with no significant differences between FCs and NFCs.

Pulmonary AVM and Stroke: Case Report from Istishari Arab Hospital

Background: Pulmonary arteriovenous malformation (PAVM) is an abnormal communication between pulmonary artery and pulmonary vein which leads to multiple manifestations that range from hypoxia to neurological manifestation such as stroke due paradoxical emboli in young patients. Chest radiography and CT-enhanced studies help in diagnosis with pulmonary angiography which is considered the gold standard study for diagnosis. Management was done with embolization of the feeding artery or arteries. Case: A 31 year old female with no previous history of medical illness, presented with sudden onset left sided weakness and was diagnosed as a case of right sided ischemic stroke. After reviewing her case by multidisciplinary team and multiple imaging studies, pulmonary angiography showed that the patient had large right lower lung lobe PAVM in addition to another right middle lung lobe and left lower lung lobe smaller PAVM. After that, patient underwent embolization of with no complications. Conclusion: PAVM, although it is rare, should be considered in differential diagnosis as the cause of neurological manifestation as ischemic stroke in young patients by paradoxical emboli. Embolization of the feeding artery or arteries is the main treatment of PAVM.

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.

Current trends in image‐guided chest interventions

Interventional radiology (IR) is a rapidly expanding medical subspecialty and refers to a range of image‐guided procedural techniques. The image guidance allows real‐time visualization and precision placement of a needle, catheter, wire and device to deep body structures through small incisions. Advantages include reduced risks, faster recovery and shorter hospital stays, lower costs and less patient discomfort. The range of chest interventional procedures keeps on expanding due to improved imaging facilities, better percutaneous assess devices and advancing ablation and embolization techniques. These advances permit procedures to be undertaken safely, simultaneously and effectively, hence escalating the role of IR in the treatment of chest disorders. This review article aims to cover the latest developments in some image‐guided techniques of the chest, including thermal ablation therapy of lung malignancy, targeted therapy of pulmonary embolism, angioplasty and stenting of mediastinal venous/superior vena cava occlusion, pulmonary arteriovenous malformation treatment and bronchial artery embolization for haemoptysis.

Advancements in Interventional Oncology of the Chest: Transarterial Chemoembolization and Related Therapies.

While embolization therapy has been used for many years in the treatment of nonmalignant diseases of the chest, such as pulmonary arteriovenous malformation treatment and bronchial artery embolization for hemorrhage, the application of transarterial techniques to the treatment of chest neoplasms is relatively uncommon. Extrapolating from transarterial chemoembolization techniques used for liver malignancy, investigators have recently sought to expand the indications for transarterial techniques from the control of symptoms such as bleeding to the control of disease progression and potentially survival benefit in patients with malignancies in the chest. This article provides an overview of the current embolotherapy techniques used in the treatment of patients with thoracic malignancies.

Successful treatment of bilateral multiple pulmonary arteriovenous malformations in a patient with brain abscess and severe hypoxemia using a combination of transcatheter embolotherapy and surgical resection: a case report

BackgroundA pulmonary arteriovenous malformation is an abnormal dilated blood vessel that makes direct communication between a pulmonary artery and pulmonary vein and can be associated with hypoxemia or neurological complications, including brain abscess and cerebral infarction. Treatment of pulmonary arteriovenous malformation includes surgical resection and transcatheter embolotherapy, however the adaptation of therapies should be considered when a patient is in bad condition.Case presentationA 51-year-old man was admitted after developing fever, consciousness disorder, and hypoxemia. Magnetic resonance imaging of the brain showed a brain abscess. Bilateral pulmonary arteriovenous malformations were found by contrast computed tomography. Because of a family history of pulmonary arteriovenous malformation, a history of epistaxis, and the existence of oral mucosa telangiectasia, he was diagnosed with hereditary hemorrhagic telangiectasia and brain abscess caused by intrapulmonary right-to-left shunt. The brain abscess improved with antibiotic treatment; however, the administration of oxygen did not ameliorate his hypoxemia. His hypoxemia was exacerbated by positive pressure ventilation. Considering his systemic and respiratory condition, we considered surgery to involve a high degree of risk. After controlling his brain abscess and pneumonia, transcatheter embolotherapy was performed. This improved his systemic condition, enabling surgical treatment.ConclusionsThis middle-aged patient suffering from brain abscess and severe hypoxemia with multiple pulmonary arteriovenous malformations was successfully treated by a combination of transcatheter embolotherapy and surgery. The adaptation and combination of therapies, as well as the sequence of treatments, should be considered depending on the patient status and lesions.

Venous Sac and Feeding Artery Embolization versus Feeding Artery Embolization Alone for Treating Pulmonary Arteriovenous Malformations: Draining Vein Size Outcomes

PurposeTo investigate and compare venous sac and feeding artery embolization (VFE) with feeding artery embolization (FAE) alone for treatment of pulmonary arteriovenous malformations (PAVMs), based on difference in outcomes in decrease of the size of the draining vein. Materials and MethodsTwenty-six patients (7 male and 19 female; median age [interquartile range], 58 years [46–65 years]) with 42 simple PAVMs treated with coil embolization between August 2005 and December 2018 were retrospectively evaluated. Twenty PAVMs were treated with FAE early in the study period and compared with 22 PAVMs treated with VFE later in the study period. Follow-up computed tomography images obtained 8–20 months after embolotherapy were used for outcome analysis. Data related to patient demographics; follow-up period; baseline diameters of the feeding artery, venous sac, and draining vein; draining vein diameter after treatment; and decrease in the size of the draining vein, including the number reaching a threshold of 70% decrease, were compared between the 2 groups. ResultsThe draining vein decreased in size by a median of 46.4% in the FAE group and 66.3% in the VFE group, and the difference between the 2 groups was statistically significant (P = .009). There were no significant differences in the other parameters. ConclusionsVFE leads to a greater decrease in the size of the draining vein than FAE, suggesting that VFE results in more complete occlusion than FAE for treatment of PAVMs.

Evaluation of percutaneous transcatheter embolization for pulmonary arteriovenous malformations

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

HIDDEN IN PLAIN SIGHT: NEW DIAGNOSIS OF PULMONARY ARTERIOVENOUS MALFORMATION AFTER ISCHEMIC COLITIS

SESSION TITLE: Medical Student/Resident Pulmonary Vascular Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pulmonary arteriovenous malformation (PAVM) is an abnormal connection between a pulmonary artery and vein, which allows blood to bypass the filter function of the capillary beds and delivers deoxygenated blood to the left heart. This condition often remains undiagnosed until thromboembolic complications present. We report the case of new diagnosis of PAVMs in a patient presenting with ischemic colitis. CASE PRESENTATION: A 58-year-old female presented with acute onset diffuse abdominal pain and emesis. She was afebrile and normotensive with nonspecific abdominal tenderness on examination. Laboratory data was significant for mild leukocytosis and normocytic anemia. Computer Topography (CT) abdomen and pelvis showed diffuse inflammation around the cecum, consistent with ischemic colitis. She underwent partial colectomy with ileostomy placement. Postoperatively, she developed acute hypoxemia. CT angiogram showed left lower lobe pulmonary embolus and multiple PAVMs (largest in left lower lobe). She was treated with anticoagulation. However, she remained hypoxic and required oxygen at discharge. Further history revealed episodic epistaxis since childhood, three prior stillbirths, miscarriage, and multiple strokes in her sister. Hypercoagulable work-up was negative. She was readmitted multiple times for hypoxia and has undergone numerous PAVM embolization procedures. Post-embolization bubble echocardiogram showed intra- and extra-cardiac shunt both confirmed by transesophageal echocardiogram. DISCUSSION: Most PAVMs are hereditary with over 80% occurring in association with hereditary hemorrhagic telangiectasia, an autosomal dominant vascular disorder. Less commonly, PAVMs are idiopathic or secondary to trauma, infection or due to hepatopulmonary syndrome. Previously viewed as rare conditions, recent data suggest PAVMs affect 1 in 2,600. Patients with PAVMs present with hypoxemia and paradoxical embolization complications, including stroke, brain abscess, and other end-organ ischemia as seen in our patient who presented with ischemic colitis. A history of recurrent nosebleeds since childhood and family history of strokes were subtle clues to the diagnosis, but as in many other cases, the PAVMs were not identified until she presented with a paradoxical thromboembolic event. Patient has persistent hypoxemia despite embolization, and we hypothesize that obliteration of the large PAVMs led to elevated pulmonary pressures, which opened the intra-cardiac shunt in addition to new intra-pulmonary shunts. CONCLUSIONS: Pulmonary AVMs often remain undetected in patients until a thromboembolic complication occurs. Increased awareness of variable presentations of pulmonary AVMs is essential for prompt diagnosis and treatment to prevent devastating complications. Reference #1: Shovlin, C. Pulmonary arteriovenous malformations. Am J Respir Crit Care Med. 2014 Dec 1; 190 (11): 1217-1228. Reference #2: Lovering, A et al. Pulmonary pathways and mechanisms regulating transpulmonary shunting into the general circulation: An update. Injury. 2010 Nov; 41(0 2): S16-S23. Reference #3: Lee, W et al. Contrast echocardiography remains positive after treatment of pulmonary arteriovenous malformations. Chest Journal. 2003 Feb; 123 (2): 351-358. DISCLOSURES: No relevant relationships by RAMYA GORTHI, source=Web Response No relevant relationships by John Mwangi, source=Web Response No relevant relationships by Mackenzie Steck, source=Web Response

Uniportal thoracoscopic surgery for pulmonary arteriovenous malformations—report of technique and case series

Background: Pulmonary arteriovenous malformations (PAVM) are abnormal direct connections between arteries and veins of the pulmonary circulatory system. In the majority of cases, they are of congenital origin and patients present with dyspnea, epistaxis or hemoptysis as the most common clinical symptoms. Before surgical treatment is considered, patients should be discussed interdisciplinary with angiologists and interventional radiologists regarding evaluation of embolotherapy. In case of unsuccessful embolotherapy, in case of complications (e.g., bleeding due to rupture of lesions), or in patients with contraindication for embolization such as untreatable contrast allergy, surgical resection of the pulmonary lesion is indicated. The former gold standard of open thoracotomy as treatment of PAVM has been mostly replaced by interventional embolization since the late 1980s. In recent years, less invasive approaches such as multi- or uniportal video-assisted thoracic surgeries (VATS) developed, have improved and have been shown to be safe and feasible treatment options, when surgery is necessary.

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.

A 3D Printable model of pulmonary arteriovenous malformations

Pulmonary arteriovenous malformations (PAVMs) are vascular anomalies in which there is a direct connection between pulmonary arteries and veins, bypassing the lung capillary bed (1). The most common cause of PAVMs are congenital, resulting from an autosomal dominant disorder, hereditary hemorrhagic telangiectasia (HHT), causing mutations in proteins important in the vascular signaling pathway (2). Complications of untreated PAVM include stroke, hypoxemia, dyspnea, platypnea, infections, and anemia (1, 3). Treatment of PAVMs is most commonly done so via endovascular embolization (1). When HHT patients develop PAVMs and come to the IR clinic to obtain treatment, they are often anxious about their diagnosis and explaining the anatomy, pathology, and treatment of their disease can present challenges to the physician. The current method of patient education uses the patient’s 2D CT scans along with the physician’s narrative, which the patient may find difficult to follow because they are not trained in reading such medical datasets. We hypothesized that having a patient interact with a 3D‐printed model of PAVM would improve their understanding of the disease and anatomy involved, and decrease their anxiety regarding their diagnosis and treatment. To test this hypothesis, we first created a 3D model using the software 3D Slicer ( www.slicer.org) to segment CT scans from a single patient with multiple, untreated PAVMs. One PAVM was chosen to be segmented for its distinctive feeding artery exiting the pulmonary trunk into these fistula and distinctive vein exiting the fistula and entering the left atrium. The 3D model was then imported into Maya where it was sculpted, artistically adjusted, and enhanced to provide anatomically accurate representation of the chest anatomy applicable to this disease, to then be printed. This novel model of a disease has the potential to decrease patient anxiety prior to the treatment of their PAVM and improve their knowledge on the anatomy and pathology. The effects of HHT patient interaction with the model on the patient’s anxiety levels and understanding of the disease remains to be investigated.CT axial section of PAVM used for segmentationFigure 13D model produced in 3D SlicerFigure 2

CIRSE Standards of Practice on Diagnosis and Treatment of Pulmonary Arteriovenous Malformations.

CIRSE Standards of Practice on Diagnosis and Treatment of Pulmonary Arteriovenous Malformations.

Embolization using hydrogel-coated coils for pulmonary arteriovenous malformations

PurposeTo prospectively evaluate the efficacy and safety of embolization using hydrogel-coated coils for the treatment of pulmonary arteriovenous malformations (PAVMs). Materials and methodsThe outcomes of 21 PAVMs in 19 patients (3 men and 16 women; mean age, 58.8±15.2 [SD] years; age range 14–78 years) treated by venous sac embolization (VSE) with additional feeding artery embolization were prospectively evaluated. For VSE, using one or more 0.018-inch hydrogel-coated coils was mandatory. Recanalization and/or reperfusion were evaluated by pulmonary arteriography 1 year after embolization. ResultsThe mean feeding artery and venous sac sizes were 4.0mm and 8.5mm, respectively. Embolization was successfully completed in 20/21 PAVMs, yielding a technical success rate of 95%. The feeding artery was also embolized in 17/20 successful PAVMs (85%). A technical failure occurred in one PAVM, where embolization was abandoned because of migration of one bare coil to the left ventricle. The mean numbers of hydrogel-coated coils and bare platinum detachable coils used for VSE were 3.3±2.1 (SD) (range, 1–8) and 4.4±3.9 (SD) (range, 1–17), respectively. The mean percentages of hydrogel-coated coils in number, length, and estimated volume were 42.9%, 33.3%, and 72.7% respectively. One patient with one PAVM was lost to follow-up after 3 months. Neither recanalization nor reperfusion was noted in the remaining 19 PAVMs (success rate, 19/19 [100%]). One grade 4 (coil migration) adverse event occurred, and it was treated without any sequelae. ConclusionVSE using hydrogel-coated coils with additional feeding artery embolization is a safe and effective treatment for PAVM.

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

BackgroundEmbolization is the standard of care for treatment of pulmonary arteriovenous malformations (PAVMs). Persistence of PAVMs after embolization occurs for undefined reasons but may include inflammation related to smoking in dysregulated angiogenesis.PurposeTo determine whether patients with hereditary hemorrhagic telangiectasia (HHT) who smoke tobacco are more prone to PAVM persistence after embolization.Materials and MethodsPatients with HHT treated for PAVMs between January 2000 and August 2017 were retrospectively identified. Only PAVMs with no previous treatment and patients with both clinical and imaging follow-up were included. Age, sex, PAVM characteristics (size, complexity, and location), embolization material used, microcatheter type, smoking history, active tobacco use, and other risk factors for arterial disease were analyzed by using a multivariate Cox proportional hazards model to determine risk factors for persistence.ResultsFive-year persistence-free survival rates in nonsmokers, smokers of 1–20 pack-years, and smokers of more than 20 pack-years were 12.2%, 21.9%, and 37.4% respectively. Smokers with more than 20 pack-years relative to nonsmokers had greater risk of persistence after adjusting for arterial feeder size (hazard ratio, 3.8; 95% confidence interval [CI]: 1.5, 10.0; P = .007). Patients who reported active tobacco use at the time of PAVM embolization had a 5-year cumulative incidence of persistence of 26.3% compared with 13.5% in inactive smokers. After adjusting for arterial feeder size, the risk of persistence was greater in tobacco users versus inactive smokers at the time of treatment (hazard ratio, 2.4; 95% CI: 1.2, 4.7; P = .01).ConclusionSmoking is associated with pulmonary arteriovenous malformation persistence after embolization in patients with hereditary hemorrhagic telangiectasia. Online supplemental material is available for this article. See also the editorial by Trerotola and Pyeritz in this issue.

Endovascular Closure of Pulmonary Arteriovenous Malformations after Cryptogenic Stroke: A Case Series

ABSTRACT Background: To investigate the clinical characteristics and treatment of patients who presented with cryptogenic stroke due to pulmonary arteriovenous malformation (PAVM). Cryptogenic stroke is occasionally caused by paradoxical embolization due to a PAVM. Endovascular closure of the PAVM is the preferred treatment, as suggested by isolated case reports. Methods: The authors retrospectively reviewed the charts of 14 patients who underwent endovascular treatment of PAVMs after an ischemic cryptogenic stroke. The patients were treated by a single interventionalist over a 15-year time period at Columbia University Medical Center. Results: All patients had suffered a prior cryptogenic stroke and 50% (7/14) experienced more than one stroke. Nearly all patients (13/14) had been referred for closure of a patent foramen ovale (PFO) diagnosed by transthoracic echocardiogram (TTE). During catheterization, use of intracardiac echocardiography, probing of the septum and local injection of saline revealed that only 29% of patients (4/14) actually had a PFO. A total of 18 PAVMs were identified: 56% were isolated right-sided, 22% were isolated left-sided, and 22% were bilateral. The majority (16/18) were simple type PAVMs with a single feeding vessel. Gianturco coils were used to treat eight patients and Amplatzer devices were used to treat seven patients (two patients received both coils and Amplatzer). No patient suffered recurrent stroke after shunt closure. Conclusions: Endovascular closure of PAVMs after cryptogenic stroke appears safe and may reduce recurrent stroke risk in this select population. Frequently, PAVM is misdiagnosed as PFO by noninvasive TTE and incidentally discovered at catheterization to close the PFO.

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

To describe our institutional experience with MVP™ micro vascular plug systems for the treatment of pulmonary arteriovenous malformations (PAVMs). 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 ≥ 2mm. 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 1-3months and 3-5years after embolization per clinical protocol. All procedures were technically successful without major complications. Mean feeding artery diameter was 3.3 ± 1.2mm. Mean fluoroscopy time per procedure and contrast volume administered per procedure were 35± 16min and 217± 101mL, 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 ± 258days (range 26to 914days). For PAVMs with feeding artery diameters of 2 to 7.9mm (mean 3.3 ± 1.2mm), 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 III.