Embolization Of Pulmonary Arteriovenous Malformations Research Articles

Hereditary haemorrhagic telangiectasias with recurrent ischemic stroke hinted by manganese deposition in the basal ganglia: a case report and literature review

BackgroundHereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant inherited vascular disorder that can involve multiple organs, thus can be associated with so many clinical departments that proper screening and diagnosis of HHT are needed for providing better management of both patients and their family members.Case presentationWe present a 58-year-old female patient with recurrent paradoxical brain embolism due to HHT. She received aspirin therapy and underwent pulmonary arteriovenous malformation embolization, recovering well and discharged 3 days postoperatively. Though ischemic stroke caused by HHT-induced vascular disorders has been reported, our patient presented with both recurrent paradoxical brain embolisms and radiologic findings of bilateral globus pallidus manganese deposition at the same time, a combination rarely reported. We also review the literature on the clinical features and management of HHT for prompt diagnosis of this genetic disease behind paradoxical embolism.ConclusionsWhen patients with ischemic stroke, especially recurrent ischemic stroke, have combined arteriovenous malformations (AVMs) in single or multiple organs, or clues for AVMs like manganese deposition in globus pallidus, genetic diseases such as HHT may be the reason for ischemic stroke and shouldn’t be missed in the evaluation of embolic sources.

Graded Transthoracic Contrast Echocardiography After Pulmonary Arteriovenous Malformation Embolization: Can Chest CT Be Avoided in Patients With a Low-Grade Shunt?

BackgroundPulmonary arteriovenous malformations (PAVMs) are direct connections between the pulmonary artery and vein, creating right-to-left shunting (RLS). Embolization is indicated to prevent complications. Guidelines recommend follow-up chest CTs to confirm persistent occlusion and embolization of all treatable PAVMs. Graded transthoracic contrast echocardiography (TTCE) after PAVM embolization may offer a reliable alternative in a subgroup of patients while preventing radiation exposure. Research questionCan TTCE predict the need for additional embolotherapy in the post-embolization population as accurately as it does in treatment-naïve population? Study design and methodsSince 2018, follow-up after PAVM embolization at the study institution includes both TTCE and chest-CT after 6-12 months and every 3-5 years thereafter. Patients who underwent at least one follow-up TTCE and chest-CT were included. The indication for additional embolotherapy was discussed in a multidisciplinary team meeting. The primary outcome was the indication for additional embolotherapy in each RLS-grade. Additionally, the association between the RLS-grade and indication for additional embolotherapy was investigated. Results339 patients with 412 embolization procedures were included, median time to follow-up TTCE was 7.5 months. A RLS was present in 399 post-embolization TTCEs (97%): RLS grade 1 in 93 patients (23%), grade 2 in 149 patients (36%) and grade 3 in 157 patients (38%). In patients with a RLS grade 0-1, no treatable PAVMs were found on CT. In patients with RLS grade 2-3, 22 (15%) and 72 (46%) underwent additional embolizations. InterpretationThis study shows chest CT might be forgone in patients with an RLS grade 0-1 after PAVM embolization.

Fusion imaging for guidance of pulmonary arteriovenous malformation embolisation with minimal radiation and contrast exposure.

Hereditary haemorrhagic telangiectasia is an inherited disorder characterised by vascular dysplasia that leads to the development of arteriovenous malformations. Pulmonary arteriovenous malformations occur in approximately 30% of patients with haemorrhagic telangiectasia. Given the complex characteristics of haemorrhagic telangiectasia lesions, the application of three-dimensional fusion imaging holds significant promise for procedural guidance and decrease in contrast and radiation dosing. We reviewed all patients who underwent transcatheter approach for pulmonary arteriovenous malformation occlusion with fusion image guidance from June 2018 to September 2023 from a single centre. A total of nine cases with haemorrhagic telangiectasia and transcatheter occlusion of pulmonary arteriovenous malformations using fusion imaging were identified. Five (56%) were male, mean age at procedure was 15.7 years (10-28 years) and mean number of pulmonary arteriovenous malformations intervened was three per patient (1-7). Two of the cases were complex repeat embolisations. The mean fluoroscopy time was 40.6 min (10.7-68.8 min), with mean contrast dose of 28.8 mL (11-60 mL; mean of 0.51 mL/kg) and mean radiation dose of 66.3 mGy (25.6-140 mGy; mean of 40.5 mGy/m2). There were no complications reported during the procedures, with no additional interventions necessary. Fusion imaging in pulmonary arteriovenous malformations embolisation for patients with haemorrhagic telangiectasia is feasible and has the potential to reduce contrast and radiation doses. To our knowledge, we describe the lowest radiation and contrast doses per patient using fusion imaging technology reported in the literature to date.

Prospective Study of Polytetrafluoroethylene-Covered Microplugs and Detachable Coils for Embolization of Pulmonary Arteriovenous Malformations: Technical Results, Procedure Times, and Costs

PurposeTo determine time to occlusion and procedure costs of embolization of pulmonary arteriovenous malformations (PAVMs) using a polytetrafluoroethylene-covered microplug compared with embolization using detachable coils. Materials and MethodsIn this prospective study, 37 patients (mean age, 39.1 years [SD ± 17.6]) with 82 PAVMs underwent embolization with microplug or detachable coils between April 2019 and January 2023. Technical success, procedure time intervals, and costs were analyzed. ResultsIn 37 patients, 82 PAVMs and 101 feeding arteries were successfully treated (microplug, 64; microplug + another device, 5; detachable coils alone, 32). Time from embolic device inserted into the catheter to device deployed and time to occlusion differed significantly between microplug and detachable coil cohorts (P < .0001 for both). Embolization with ≥1 microplug had a significantly shorter occlusion time than embolization with detachable coils (median, 10.0 minutes saved per feeding artery) (P < .0001). Compared with detachable coil embolization, microplug embolization saved a median of 9.0 minutes per feeding artery (P < .0001) and reduced room cost by a median of $429 per feeding artery (P < .0001). Device costs per feeding artery did not differ significantly between microplug ($2,790) and detachable coil embolization ($3,147) (P = .87). ConclusionsCompared with coils, microplugs had an equally high technical success rate but significant time to occlusion and room costs savings per feeding artery. Total room cost and device cost together did not differ significantly between microplugs and coils. Microplugs may be considered technically effective and at least cost-neutral for PAVM embolization where clinically appropriate.

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.

Preliminary Experience with a Low-Profile High-Density Braid Occluder for Transcatheter Embolization of Pulmonary Arteriovenous Malformations

This brief report describes safety, technical feasibility, and early treatment effectiveness of the low-profile braided occluder (LOBO; Okami Medical, San Diego, Caliornia) for embolization of 9 pulmonary arteriovenous malformations (PAVMs) in 4 patients (3 female and 1 male; age range: 33 to 63 years; 3 patients showed positive results for hereditary hemorrhagic telangiectasia genes). A total of 10 occluders were deployed in 10 vessels (median treated vessel diameters, 3 and 4 mm for LOBO-3 and LOBO-5 groups, respectively). All devices were successfully deployed into the feeder pulmonary arteries, achieving complete cessation of flow. There were no severe adverse events or device migrations. Available short-term follow-up computed tomography (6 PAVMs: median, 7 months; range, 1.5–7 months) demonstrated complete occlusion without persistence or recanalization. The early experience of embolization of PAVMs using a low-profile braided occluder showed it to be safe and effective. Further studies with larger cohorts and longer follow-up periods are warranted.

An Update on Embolization for Pulmonary Arteriovenous Malformations.

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

Comparison of Transthoracic Contrast Echocardiography with High-Resolution Chest CT after Embolization of Pulmonary Arteriovenous Malformation

PurposeTo compare postembolotherapy follow-up graded transthoracic contrast echocardiography (TTCE) and high-resolution computed tomography (CT) of the chest and to evaluate the use of graded TTCE in the early postembolic period. Materials and MethodsThirty-five patients (6 men and 29 women; mean age, 56 years; range, 27–78 years) presenting for postembolotherapy follow-up between 2017 and 2021 with concurrent high-resolution CT and graded TTCE were analyzed retrospectively. Untreated pulmonary arteriovenous malformations (PAVMs) with a feeding artery of ≥2 mm were considered treatable. ResultsNinety-four percent of patients (33 of 35) did not have treatable PAVMs on high-resolution CT. TTCE was negative for shunts (Grade 0) in 34% of patients (n = 12). Of patients with a TTCE positive for shunts (23 of 35, 66%), 83% had a Grade 1 shunt, 13% had a Grade 2 shunt, and 4% had a Grade 3 shunt. No patient with a Grade 0 or 1 shunt had a treatable PAVM on high-resolution CT. Of the 2 patients with PAVMs requiring treatment, one had a Grade 2 shunt and one had a Grade 3 shunt. TTCE grade was significantly associated with the presence of a treatable PAVM on high-resolution CT (P < .01). ConclusionsGraded TTCE predicts the need for repeat embolotherapy and does so reliably in the early postembolotherapy period. This suggests that graded TTCE can be utilized in the postembolotherapy period for surveillance, which has the potential to lead to a decrease in cumulative radiation in this patient population.

Twenty-Seven-Year Retrospective Review of Hemoptysis from Systemic Collaterals Following Pulmonary Arteriovenous Malformation Embolization

To determine the prevalence of hemoptysis secondary to post-embolization systemic collaterals and review the recurrence rate and treatment outcomes. The records of 930 patients with PAVM (801 with known or possible HHT), from a single HHT center between July 2, 1996 and July 22, 2021, were searched for a single lifetime episode of hemoptysis secondary to post-embolization systemic collaterals. Embolization was performed with permanent particles or gelatin slurry. Clinical features and treatment outcomes of identified patients were reviewed. Twenty-eight embolization procedures have been performed in 9 patients with post-PAVM embolization systemic artery collateral reperfusion. This included 8 patients with known HHT. Permanent particles were used in 5 cases and gelatine slurry was used in 19 cases. Due to the recurrence of hemoptysis, four patients required four embolizations each, two patients required three embolizations and two patients required two embolizations. Chronic unresolving hemoptysis was the presentation in 5 patients and massive hemoptysis requiring ICU admission in 4. The lifetime prevalence and incidence of hemoptysis secondary to systemic artery reperfusion in HHT patients was estimated to be 1.0% and 0.05%, respectively. Bronchial artery origin was most common (8 patients). In the first patient treated at this center, a major adverse event resulting in myocardial infarct and stroke occurred with the use of 300-500-micron permanent particles. This was presumed to be due to left-to-right shunting and subsequent systemic embolization. Subsequent patients were treated with gelatin sponge slurry without adverse events. This patient ultimately expired due to large volume hemoptysis, in the setting of bilateral diffuse PAVMs. A second patient, with history of childhood bronchial artery coil embolization, expired from large volume hemoptysis while awaiting lobectomy. In two cases, patients underwent surgery, including one lobectomy and one pneumonectomy, for recurrent hemoptysis (requiring at least five hospital admissions). The remaining five patients achieved prolonged resolution of hemoptysis with endovascular treatment alone. Lifetime prevalence of hemoptysis secondary to PAVM post-embolization systemic collaterals is rare, but recurrence is high. In this limited series, embolization with gelatin sponge slurry appeared safe, although surgical resection may ultimately be required in refractory and multifocal disease.

Evolution of Pulmonary Arteriovenous Malformations: The Role of Contrast Echocardiography

Pulmonary arteriovenous malformations (PAVMs) are direct connections between the pulmonary artery and the pulmonary vein, mostly associated with hereditary hemorrhagic telangiectasia (HHT). PAVMs can lead to severe neurologic complications such as stroke and brain abscess. The risk of complications decreases after embolization. Therefore, screening for PAVMs using transthoracic contrast echocardiography (TTCE) is recommended, including a rescreening interval of 5 years. Is extension of the interval for rescreening patients without a pulmonary right-to-left shunt (RLS) of up to 10 years appropriate? Adult patients with HHT with 5- or 10-year follow-up TTCE, or both, were included. Patients who underwent PAVM embolization in the past or at baseline were excluded. The RLS grades and presence of a treatable PAVM were compared with baseline. In total, 387 patients (median age, 45 years [interquartile range, 33-54 years]; 56%women) involving 5- and 10-year follow-up data in 363 and 166 patients, respectively, were included. None of the patients (n= 148) without a pulmonary RLS at baseline demonstrated a treatable PAVM after 5 and 10 years. Of the patients with a pulmonary RLS at baseline, 20 patients (9%) and three patients (3%) demonstrated a treatable PAVM at the 5- and 10-year follow-up, respectively. In most patients, the RLS grade remained stable over time. On the basis of the results of this retrospective study, we believe that the rescreening interval for patients with HHT without a pulmonary RLS at initial screening may be extended to 10 years. Those with a pulmonary RLS should be rescreened every 5 years because treatable PAVMs can evolve.

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

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

DYSPNEA DURING PREGNANCY REVEALING MULTIPLE PULMONARY ARTERIOVENOUS MALFORMATIONS AND A NEW DIAGNOSIS OF HEREDITARY HEMORRHAGIC TELANGIECTASIA

DYSPNEA DURING PREGNANCY REVEALING MULTIPLE PULMONARY ARTERIOVENOUS MALFORMATIONS AND A NEW DIAGNOSIS OF HEREDITARY HEMORRHAGIC TELANGIECTASIA

Concurrent pulmonary arteriovenous malformation and pulmonary embolism causing stroke: a therapeutic dilemma

BackgroundAs pulmonary arteriovenous malformation (PAVM) include a right-to-left shunt, it can be accompanied by fatal complications such as stroke and brain abscess due to paradoxical embolism. A concurrent PAVM and pulmonary embolism (PE) is a rare condition. Therefore, the sequence of management has not been established.Case presentationA 62-year-old female patient was transferred to our hospital with a sporadic simple PAVM and concurrent bilateral PE. On chest computed tomography (CT), the acute PE was extended to the segmental pulmonary artery where the feeding artery of PAVM originated. Despite the anticoagulation, the patient complained of left sided weakness on the fifth day of admission, and magnetic resonance imaging revealed an acute infarction in the right lateral thalamus, which was thought to be caused by paradoxical embolism. This situation could lead to a dilemma between the risk of thrombus migration during PAVM embolization and another embolic event due to delayed shunt occlusion during anticoagulation. After a multidisciplinary discussion, a delayed endovascular embolization was performed for PAVM after confirming the complete resolution of PE with 4 months of anticoagulation. The cause of PE in this patient was eventually diagnosed as antiphospholipid syndrome.ConclusionThe authors reported a rare case of concurrent PAVM and PE that led to an embolic stroke during hospitalization. This patient was managed with delayed endovascular embolization for PAVM after an anticoagulation for PE and stroke. It is thought to be valuable in deciding for a treatment plan for this rare condition.

Cyanosis in a Previously Well Child.

Cyanosis in a Previously Well Child.

Pulmonary Arteriovenous Malformation Embolization: So Much Left to Learn

Embolization of pulmonary arteriovenous malformations (PAVMs) has been utilized effectively for more than 40 years. Initially performed using conventional coils and/or detachable balloons in the era of cut-film angiography, currently, there is an armamentarium of embolic devices and methods for effecting therapy. Two studies in this issue of the Journal of Vascular Interventional Radiology compare traditional feeding artery embolization with venous sac (“nidal”) embolization, and in both, sac embolization appeared to improve the occlusion rate of lesions (1,2).

Abstract No. 64 Analysis of complications and unsuccessful embolization of pulmonary arteriovenous malformations

Embolotherapy is the standard treatment for pulmonary arteriovenous malformation (pAVM). The purpose of this study is to explore the reasons for unsuccessful embolization and complications associated with embolotherapy. This retrospective chart review study was approved by the IRB. Data were collected for all the embolization procedures that were performed at our institution for pulmonary AVM treatment between January 2003 and January 2020. All ages of both genders were included in the analysis. The reason for unsuccessful embolization and complications were recorded. One hundred and eighty-seven patients had a total of 341 embolization procedures at our institutions for the treatment of PAVM. There were 240 (70%) women and 101 (30%) men included with a mean age of 49 ± 18 and 38 ± 20 years, respectively. The average fluoroscopic time was 34 minutes (range 3.4 to 120 minutes). Of 341, 47(14%) procedures were unsuccessful. The reason for unsuccessful embolization were (in order of frequency): no PAVM detected on catheter angiogram (n = 17, 36%), pAVM too small to treat (n = 12, 25%), tortuous feeding artery causing technical difficulty assessing the artery (n = 7, 15%), No evidence of reperfusion on follow up pulmonary angiogram (that were done to detect reperfusion) (n = 6, 13%), systemic arterial supply to the pAVM causing vein to vein shunting (n = 3, 6%), patient’s condition (increased respiratory motion and intraprocedural bradycardia) aborting the procedure (n = 2, 4%). There were a total of 9 (2%) intraprocedural complications with 2 major complications aborting the embolotherapy. Embolization of pulmonary arteriovenous malformation is a very successful procedure with minor complications. The main reasons of unsuccessful embolotherapy are no evidence of pAVM during catheter angiogram, very small feeding artery size, and tortuous feeding artery.

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.

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

BackgroundTo 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.MethodsA 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.ResultsForty-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.ConclusionsThe 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.

Location of embolization affects patency after coil embolization for pulmonary arteriovenous malformations: importance of time-resolved magnetic resonance angiography for diagnosis of patency.

This study aimed to assess the diagnostic accuracy of computed tomography (CT) and time-resolved magnetic resonance angiography (TR-MRA) for patency after coil embolization of pulmonary arteriovenous malformations (PAVMs) and identify factors affecting patency. Data from the records of 205 patients with 378 untreated PAVMs were retrospectively analyzed. Differences in proportional reduction of the sac or draining vein on CT between occluded and patent PAVMs were examined, and receiver operating characteristic analysis was performed to assess the accuracy of CT using digital subtraction angiography (DSA) as the definitive diagnostic modality. The accuracy of TR-MRA was also assessed in comparison to DSA. Potential factors affecting patency, including sex, age, number of PAVMs, location of PAVMs, type of PAVM, and location of embolization, were evaluated. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CT were 82%, 81%, 77%, 85%, and 82%, respectively, when the reduction rate threshold was set to 55%, which led to the highest diagnostic accuracy. The sensitivity, specificity, PPV, NPV, and accuracy of TR-MRA were 89%, 95%, 89%, 95%, and 93%, respectively. On both univariable and multivariable analyses, embolization of the distal position to the last normal branch of the pulmonary artery was a factor that significantly affected the prevention of patency. TR-MRA appears to be an appropriate method for follow-up examinations due to its high accuracy for the diagnosis of patency after coil embolization of PAVMs. The location of embolization is a factor affecting patency. • Diagnosis of patency after coil embolization for pulmonary arteriovenous malformations (PAVMs) is important because a patent PAVM can lead to neurologic complications. • The diagnostic accuracies of CT with a cutoff value of 55% and TR-MRA were 82% and 93%, respectively. • The positioning of the coils relative to the sac and the last normal branch of the artery was significant for preventing PAVM patency.