Embolization Of Pulmonary Arteriovenous Malformations Research Articles

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

Cardiac catheterization for hemoptysis in a Children’s Hospital Cardiac Catheterization Laboratory: A 15 year experience

ObjectivesThe aim of this study was to evaluate the diagnostic utility of cardiac catheterization and the efficacy of transcatheter intervention in patients with hemoptysis. BackgroundCardiac catheterization may play a role in identifying the etiologies of hemoptysis with the potential for transcatheter intervention. MethodsThis was a retrospective study of all the patients who were brought to the pediatric cardiac catheterization laboratory for the indication of hemoptysis over a 15-year period (2006–2020). ResultsTwenty-one patients underwent 28 cardiac catheterizations. The median age was 17.4 years (range 0.3–60.0 years), and the underlying cardiac diagnoses were normal heart n = 3, pulmonary hypertension 1, heart transplant 1, pulmonary arteriovenous malformation 1, pulmonary vein disease 3, biventricular congenital heart diseases 5, and single ventricles 7. The diagnostic utility of catheterization was 81% (17/21). At two-thirds (18/28) of catheterizations, transcatheter interventions were performed in 14/21 (67%) patients: aortopulmonary collateral embolization 14, aortopulmonary and veno-venous collateral embolization 1, and pulmonary arteriovenous malformation embolization 3. Although recurrent hemoptysis was frequent (50%) post-intervention, the final effectiveness of transcatheter interventions was 79% (11/14 patients). Overall mortality was 19% (4/21), all in those presenting with massive hemoptysis. ConclusionsCardiac catheterization was shown to have good diagnostic utility for hemoptysis especially in patients with underlying congenital heart disease. Despite the high mortality and recurrent hemoptysis rate, transcatheter interventions were effective in our cohort.

Prise en charge d’une malformation artério-veineuse pulmonaire avec hypertension pulmonaire

Pulmonary arteriovenous malformations (PAVM) are abnormal communications between arteries and pulmonary veins without interposition of capillaries. Embolization is effective both in reducing lifetime complications associated with PAVM and in improving arterial oxygenation. Embolization is however not recommended in patients with pulmonary hypertension (PH) as it abolishes low resistance pathways for pulmonary blood flow and therefore might be expected to elevate pulmonary arterial pressure (PAP). We report the case of a 70-year-old patient with a large PAVM as well as group 3 PH [mean PAP=21mmHg, pulmonary vascular resistance (PVR) at 3.4 Wood units] secondary to stage 2 chronic obstructive pulmonary disease (COPD) with emphysema. According to the measured shunt flow (26% of cardiac output), predicted post-embolization PVR was estimated at 4.6 Wood units. These values were considered compatible with embolization of the PAVM. Dyspnea and gas exchange improved after PAVM embolization, without worsening PH. Embolization of a PAVM can be considered in patients with stable PH but requires careful prior hemodynamic assessment. The estimation of the shunt flow and predicted post-embolization PVR may guide the therapeutic decision.

RECURRENT ISCHEMIC STROKE SECONDARY TO PULMONARY ARTERIOVENOUS MALFORMATIONS

SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder that has a variety of clinical manifestations and can affect many organ systems. Prevalence rates of HHT are estimated to be between 1:5000 and 1:8000. Knowledge of the risk of developing pulmonary arteriovenous malformations associated with HHT is essential to prevent potentially catastrophic complications, including stroke. CASE PRESENTATION: A 42 year-old female, non-smoker with hereditary hemorrhagic telangiectasia, headaches, epistaxis, and multiple strokes presented with an hour of dizziness, slurred speech, and right sided weakness. Her symptoms completely resolved within three hours of arrival. Family history was significant for three family members with HHT. On physical exam she had dried blood in her nares and multiple blanching telangiectasias on her lips and arms. Her lungs were clear without adventitious sounds on room air and she had no neurologic deficits. CT scan of the head did not demonstrate acute hemorrhage. She had a normal ejection fraction with a positive bubble study on contrast enhanced echocardiogram. She coughed up a quarter-sized bright red blood clot after arrival. She denied a history of massive hemoptysis. CT chest demonstrated a two centimeter right pulmonary arteriovenous malformation (AVM) in the right lower lobe, an eight millimeter left lower lobe AVM, and multiple smaller AVMs throughout both lungs. She underwent coil embolization of the largest AVMs by interventional radiology, and post-embolization angiogram showed no further flow in the arterial branches feeding the AVMs. Within two months, her headaches had improved and she was no longer developing transient slurred speech or unilateral weakness. DISCUSSION: Pulmonary AVMs in patients with HHT are under recognized and undertreated as patients are often asymptomatic, and patients with HHT can have catastrophic strokes before their AVMs are identified. The incidence of pulmonary AVMs in patients with HHT exceeds 50%. In this case, the patient had two strokes secondary to paradoxical emboli before her pulmonary AVMs were identified. The British Thoracic Society recommends that all patients over age 16 with known or suspected HHT should be offered screening for pulmonary AVMs, and that patients with pulmonary AVMs should be considered for referral for embolization. CONCLUSIONS: Screening for asymptomatic pulmonary AVMs and subsequent embolization of pulmonary AVMs in hereditary hemorrhagic telangiectasia is critical to decreasing the morbidity and mortality associated with cerebral abscess and cerebral ischemia from paradoxical emboli, hemoptysis, and hemothorax associated with pulmonary AVMs secondary to HHT. Reference #1: Dupuis-Girod S, Cottin V, Shovlin C, L. The Lung in Hereditary Hemorrhagic Telangiectasia. Respiration. 2017; 94:315-330. Reference #2: Shovlin CL, Condliffe R, Donaldson JW on behalf of the British Thoracic Society, et al. British Thoracic Society Clinical Statement on Pulmonary Arteriovenous Malformations. Thorax. 2017; 72:1154-1163. DISCLOSURES: No relevant relationships by Daniel Hershberger, source=Web Response No relevant relationships by Maureen McElligott, source=Web Response

A case of large spontaneous hemothorax in patient with pulmonary arterio-venous malformation of left lung

Spontaneous hemothorax is an uncommon condition that often requires immediate radical surgery. Pulmonary arteriovenous malformations (PAVM) is a rare lung vascular anomaly that progresses in time and in 8% of cases leads to either pulmonary hemorrhage or massive hemothorax as potentially fatal complications. We present a clinical case of spontaneous large hemothorax, which developed on PAVM and leaded to huge aneurysm of the lower lung lobe. The patient underwent left lower lobectomy successfully. Nowadays to prevent life-threatening complications of PAVM, all patients should undergone miniinvasive planned surgical technique - endovascular occlusion (embolization) of 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.

Retrospective Comparison of Pulmonary Arteriovenous Malformation Embolization with the Polytetrafluoroethylene-Covered Nitinol Microvascular Plug, AMPLATZER Plug, and Coils in Patients with Hereditary Hemorrhagic Telangiectasia

PurposeTo evaluate effectiveness of the polytetrafluoroethylene-covered nitinol mesh microvascular plug (MVP) and compare it with other devices in pulmonary arteriovenous malformation (PAVM) embolization in patients with hereditary hemorrhagic telangiectasia (HHT). Materials and MethodsTwenty-five patients (average age 35 y; range, 15–56 y) with hereditary hemorrhagic telangiectasia (HHT) and de novo PAVM embolization with at least 1 MVP between November 2015 and May 2017 were retrospectively evaluated. Retrospective data were also obtained from prior embolization procedures in the same patient population with other embolic devices dating back to 2008. Technical success, complications, PAVM persistence rates, and category of persistence were analyzed. ResultsIn 25 patients, 157 PAVMs were treated: 92 with MVP, 35 with AMPLATZER vascular plug (AVP), 6 with AVP plus coils, and 24 with coils. The per-PAVM technical success rates were 100% with MVP; 97%, AVP; 100%, AVP plus coils; and 100%, coils. PAVM persistence rates and median follow-up were as follows: MVP, 2% (1/92) (510 d); AVP, 15% (3/20) (1,447 d); AVP plus coils, 20% (1/5) (1,141 d); coils, 46.7% (7/15) (1,141 d). Persistence owing to recanalization for MVP, AVP, AVP plus coils, and coils was 2%, 15%, 0%, and 33%. No difference was found between persistence rates of MVP vs AVP (P = .098). Embolization with a vascular plug (MVP or AVP) with or without coils had a statistically significant lower persistence rate (5.4%) than embolization with coils alone (46.7%) (P = .022). ConclusionsPAVM embolization with MVP had a high technical success rate and a low persistence rate comparable to AVP and lower than coil embolization alone.

Patients with in-situ metallic coils and Amplatzer vascular plugs used to treat pulmonary arteriovenous malformations since 1984 can safely undergo magnetic resonance imaging.

Objective:To examine the MRI safety of metallic coils and Amplatzer vascular plugs. Currently, concern regarding MR safety of devices used to treat pulmonary arteriovenous malformations (PAVMs) causes delays in performing emergency MRI in patients presenting with acute neurological symptoms.Methods:A retrospective audit was performed on all patients who underwent PAVM embolization at Hammersmith Hospital, London UK between 1984 and 2017. Outcomes of all MRI studies performed at our institution were recorded. In addition, known outcomes of all known MRI studies performed on patients treated with the earliest steel coils (1984–1995) were recorded.Results:At our institution, 20 patients underwent 1.5 T MRI after the insertion of 100 steel coils (15.5 – 28.6, median 22 years later), 140 coils designated MR-conditional (0.42 – 12.7, median 9.3 years later), and 54 MRI-conditional Amplatzer vascular plugs (0.17 – 8.0, median 0.75 years later), many in combination. The majority of scans were for cerebral indications, but other body regions scanned included spinal, thoracic, and pelvic regions. No adverse events were reported. Similarly, there were no adverse events in any MR scan known to have been performed in other institutions in seven further patients treated with the earliest steel coils (1984–1995). Again, the majority of scans were for cerebral indications.Conclusion:The findings demonstrate MR safety at 1.5 T of all PAVM embolization devices inserted in a main UK centre since inception in 1984.Advances in knowledge:MRI of patients who have had PAVMs treated by embolization can be implemented without contacting specialist pulmonary arteriovenous malformation treatment centres for approval.

Long-Term Single-Center Retrospective Follow-Up After Embolization of Pulmonary Arteriovenous Malformations Treated Over a 20-year Period: Frequency of Re-canalization with Various Embolization Materials and Clinical Outcome.

The present study is a register-based observational study of an unselected consecutive patient cohort with pulmonary arteriovenous malformations (PAVMs) from a single national hereditary hemorrhagic telangiectasia and PAVM embolization center. The aim was to investigate the frequency of re-embolizations and the clinical outcome after embolization with the use of different embolization materials further, to define which PAVM morphology and size of feeding arteries that most often were re-embolized, and to estimate the clinical outcome of the patients including those that were re-embolized. The population was included from 1996 until 2016 and was made up of a total of 136 patients with 322 PAVMs. Median follow-up was 38.3 (0.3-241 months). The re-embolization rate was 9.3%. None of the PAVMs treated with detachable silicone balloons were re-embolized, while 4.5% treated with vascular plugs and 11.7% treated with coils were re-embolized (p=0.07). In total, 16/74 complex PAVMs were re-embolized compared with 14/248 simple PAVMs. In big-sized feeding arteries ≥ 6mm, 16/112 were re-embolized compared with 14/210 with smaller-sized feeding arteries. Out of the 30 re-embolized PAVMs, 23 resulted in a successful clinical outcome. Our results suggest that standard coils probably should not be the first choice for embolization of PAVMs, and vascular plug alone or in combination with coils might be a better primary option for embolization in these patients. Level 3A, non-randomized case controlled cohort/follow-up study.

Efficacy and Safety of AMPLATZER Vascular Plug Type IV for Embolization of Pulmonary Arteriovenous Malformations

PurposeTo assess the efficacy and safety of the AMPLATZER Vascular Plug type IV for pulmonary arteriovenous malformation (PAVM) treatment. Materials and MethodsBetween June 2013 and January 2018, 13 patients with 26 PAVMs were treated with the type IV AVP. Patients without follow-up computed tomography (CT) were excluded. Technical success was defined as flow occlusion on angiography. Plug-to-sac distance was measured on angiographic images. Feeding artery and venous sac diameter changes were measured on preprocedural and follow-up CT. Successful embolization was defined as > 70% sac size regression. Procedure time, device migration, and complications were evaluated. ResultsNine female patients (mean age, 49 y; range, 40–71 y) with 19 PAVMs were enrolled. Four patients with 7 PAVMs were lost to follow-up. Nineteen PAVMs were treated in 11 sessions, and the mean procedure time was 29 min. The technical success rate was 100%. Mean feeding artery diameter was 3.1 mm ± 0.7 (range, 2.1–4.9 mm). Mean plug-to-sac distance was 5.4 mm ± 4.9 (range, 0–13.3 mm). The mean CT follow-up period was 14 months ± 7 (range, 6–30 mo). Sixteen of 19 PAVMs (84%) were successfully embolized. Minor complications (tachycardia and chest discomfort) arose in 2 of 11 sessions. No device migrations or major complications occurred. ConclusionsThe type IV AVP showed an 84% treatment success rate based on 70% sac size regression criteria in small PAVMs. There were no device migrations or major complications.

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.

Pulmonary arteriovenous malformations: a radiological and clinical investigation of 136 patients with long-term follow-up

To assess the clinical outcome of patients with and without hereditary haemorrhagic telangiectasia (HHT) after embolisation of pulmonary arteriovenous malformations (PAVM) from a single national centre. The present register-based observational study including all patients with PAVM treated with embolisation at a reference centre for HHT and PAVM was undertaken over a 20-year period. Demographic data, HHT genotyping, clinical presentation, and outcome were registered. Patients with HHT were compared to the patients without HHT. Clinical examination, contrast-enhanced echocardiography, and computed tomography (CT) were used to assess the clinical outcome at follow-up. One hundred and thirty-six patients with 339 PAVM underwent embolisation during the study period: 22 did not have HHT; 62% had HHT1, 10% had HHT2, 4% had JP-HHT, 8% had clinical HHT without identified genetic mutations. Solitary PAVM were more common among patients without HHT than with HHT. Mean follow-up after the first embolisation was 58 months. Mean age at first embolisation was 46.5 years, and at last follow-up 51.8 years. The clinical success without shunt at follow-up was 87%. The 30-day mortality related to the embolisation was 0%. Twenty patients died during follow-up (mean age 69 years). Most patients could be treated during one session, but many will need a long follow-up with repeated clinical examinations and embolisation. The majority of patients referred for embolisation of PAVM had HHT. Multiple PAVM is associated with HHT. Patients with PAVM should be screened for HHT and patients with HHT for PAVM. Embolisation is a safe procedure with high clinical success.

Pulmonary arteriovenous malformations in children with hereditary hemorrhagic telangiectasia: a longitudinal study.

Pulmonary arteriovenous malformations (PAVMs) often occur in children with hereditary hemorrhagic telangiectasia (HHT). A 14-year longitudinal study of PAVMs in children with HHT was undertaken to assess the prevalence, the clinical impact, and progression of these malformations. This was a retrospective, single-center study from May 2002 to December 2016 of 129 children with HHT diagnosed using Curacao criteria and/or confirmed by genetic testing. Transthoracic contrast echocardiography (TTCE) was the primary screening modality in all patients and PAVMs were diagnosed based on Barzilai criteria. Moderately positive TTCE (Barzilai criteria ≥ 2) was confirmed with subsequent contrast chest CT. New PAVMs were diagnosed with a positive TTCE after an initial negative TTCE. Embolization of PAVMs were performed according to HHT consensus guidelines. Of 129 children with HHT, 76 (59%) were found to have PAVMs. Sixty-seven (88%) were positive for PAVMs on initial screening. Of 63 children without PAVMs on initial screening, 31 were followed for >1 year. Nine of the 31 (29%) developed new PAVMs after initial negative study. Thirty-eight (50%) of the total 76 children with PAVMs had or developed lesions large enough to be treated with embolization. Nine patients with PAVMs initially too small to be treated with embolization, developed progression of disease and ultimately were treated with embolization over time. The majority, 60% (23/38), of the children with large PAVMs had no related clinical symptoms. After embolization, 21% (8/38), of patients underwent repeat interventions. Genetic diagnosis, age, and gender were not associated with risk of having PAVM nor with need for repeat interventions. Nearly 60% of children with HHT develop PAVMs. The risk for new PAVMs to develop, small PAVMs to become large, and previously embolized PAVMs to require further intervention remains throughout childhood. Thus, children with HHT require continued follow-up until adulthood.

Abstract No. 482 Morphological comparison before and after coil embolization of pulmonary arteriovenous malformations on computed tomographs

To examine morphological changes of pulmonary arteriovenous malformations (PAVMs) before and after coil embolization on computed tomographs (CT). Between October 2012 and October 2016, 7 patients (1 male, 6 females, median age 70 years) with 10 PAVMs who improved clinically after coil embolization (CE) of sac PAVMs were enrolled. Pre- and post-CE morphological comparisons included the diameter of the feeders and drainers, the sac volume, and the shrinkage rate the feeding and draining vessels. Computational fluid dynamics (CFD) analysis was performed in 3 patients. The median follow-up was 360 days (range, 26-1376 days). The average diameter before and after CE of the feeding vessel was 4.4- and 2.8 mm, of the drainage vessel it was 3.7- and 2.5 mm. The average pre- and post-CE sac volume was 211.49 mm3 (median 200.63 mm3). The average shrinkage rate of the feeders and drainers was 37.2% and 33.7%, respectively; the pre- and post-CE diameter of the feeders and drainers was significantly different (p = 0.0001). There was no statistically significant correlation between the sac volume and the shrinkage rate of the feeding- (r = -0.3108, p = 0.3820) and the draining vessels (r = 0.09978, p = 0.7839). CFD analysis showed that most of the blood flow from the feeders passed through the PAVM sac. CDF analysis of virtual CE of PAVMs indicated that feeders and drainers were subject to increased wall shear stress (WSS) and that their oscillating shear index (OSI) was increased. Comparison of pre- and post-CE CT images of PAVMs showed that after the procedure, the diameter of the feeders and drainers was significantly smaller. We think that the absence of a correlation between the sac volume and the shrinkage rate of the feeding and draining vessels is attributable to a post-CE increase in the WSS and OSI.

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

PurposeTo evaluate the usefulness of hydrogel-coated coils for preventing recanalization after coil embolization of pulmonary arteriovenous malformations (PAVMs).Materials and MethodsThirty-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.ResultsIn 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.ConclusionsHydrogel-coated coils may be useful for preventing recanalization after the embolization of PAVMs.

Embolisation for pulmonary arteriovenous malformation.

Pulmonary arteriovenous malformations are abnormal direct connections between the pulmonary artery and pulmonary vein which result in a right-to-left shunt. They are associated with substantial morbidity and mortality mainly from the effects of paradoxical emboli. Potential complications include stroke, cerebral abscess, pulmonary haemorrhage and hypoxaemia. Embolisation is an endovascular intervention based on the occlusion of the feeding arteries the pulmonary arteriovenous malformations thus eliminating the abnormal right-to-left-shunting. This is an update of a previously published review. To determine the efficacy and safety of embolisation in patients with pulmonary arteriovenous malformations including a comparison with surgical resection and different embolisation devices. We searched the Cystic Fibrosis and Genetic Disorders Group's Trials Register; date of last search: 10 April 2017.We also searched the following databases: the Australian New Zealand Clinical Trials Registry; ClinicalTrials.gov; International Standard Randomised Controlled Trial Number Register; International Clinical Trials Registry Platform Search Portal (last searched 27 August 2017). to be updatedWe checked cross-references and searched references from review articles. Trials in which individuals with pulmonary arteriovenous malformations were randomly allocated to embolisation compared to no treatment, surgical resection or embolisation using a different embolisation device. Studies identified for potential inclusion were independently assessed for eligibility by two authors, with excluded studies further checked by a third author. No trials were identified for inclusion in the review and hence no analysis was performed. There were no randomised controlled trials included in the review; one ongoing trial has been identified which may be eligible for inclusion in the future. There is no evidence from randomised controlled trials for embolisation of pulmonary arteriovenous malformations. However, randomised controlled trials are not always feasible on ethical grounds. Accumulated data from observational studies suggest that embolisation is a safe procedure which reduces morbidity and mortality. A standardised approach to reporting with long-term follow-up through registry studies can help to strengthen the evidence for embolisation in the absence of randomised controlled trials.

Endovascular embolisation strategies for pulmonary arteriovenous malformations.

PurposeTo assess the immediate efficacy of distinct embolisation devices in the endovascular treatment of pulmonary arteriovenous malformations as well as to identify and analyse the possible determinants of the technical success of the procedure.Material and methodsProspective analysis of 16 consecutive patients was carried out, who underwent transcatheter endovascular embolisation therapy for pulmonary arteriovenous malformations between 2005 and 2017. Pre- and post-procedural angiography studies were implemented to confirm the diagnosis and to evaluate the technical success defined as the complete occlusion of the feeding artery. Embolisation devices – coils, microcoils, occluders, or combination of the above – were used. All the patients were advised to conduct a follow-up computed tomography evaluation 12 months after the procedure.ResultsA total of 40 pulmonary arteriovenous malformations (PAVMs) were observed and embolised. The immediate technical success was achieved in all (n = 40; 100%) treated PAVMs, as confirmed by the post-procedural angiographic result. The statistical analysis revealed no significant impact of the number of PAVMs per patient (p > 0.05), their angioarchitecture (p > 0.05), localisation within the lung (p > 0.05) or particular lobe (p > 0.05), and the selection of embolisation device (p > 0.05) on the procedural success rates. The procedure-related complication rate was equal to 6.25%.ConclusionsThe immediate success rate of the transcatheter PAVM embolisation reached 100% in this study. The statistical model of logistic regression revealed no significant impact of the number of PAVMs per patient, their angioarchitecture, localisation, and distribution pattern, as well as device selection, on the immediate technical success of the procedure.

Pulmonary Hypertension Prevalence and Prognosis in a Cohort of Patients with Hereditary Hemorrhagic Telangiectasia Undergoing Embolization of Pulmonary Arteriovenous Malformations.

Pulmonary Hypertension Prevalence and Prognosis in a Cohort of Patients with Hereditary Hemorrhagic Telangiectasia Undergoing Embolization of Pulmonary Arteriovenous Malformations.

The effect of embolization of pulmonary arteriovenous malformations on migraine among patients with hereditary hemorrhagic telangiectasia

The effect of embolization of pulmonary arteriovenous malformations on migraine among patients with hereditary hemorrhagic telangiectasia

Clinical Significance of Pulmonary Arteriovenous Malformation Reperfusion

AbstractThe purpose of this study was to assess the clinical significance of reperfused pulmonary arteriovenous malformations (rPAVM) after embolization. This study is a retrospective review of all patients from a single HHT center who underwent pulmonary arteriovenous malformation (PAVM) embolization between January 1, 2006 and December 30, 2007. Clinical history, imaging findings (including reperfusion), and symptoms seen in the setting of PAVMs were reviewed both at the time of embolization and during the subsequent follow-up through December 30, 2013. During the 2-year treatment period, 101 patients underwent PAVM embolization. During the initial embolization, 27 patients were found to have reperfusion of a previously embolized PAVM. During the follow-up period, none of these patients had recurrence of the rPAVM. Three patients who underwent an embolization procedure for the first time at the initial procedure were subsequently found to have rPAVM during the follow-up period. This resulted in a total of 30 patients with rPAVMs. Eighteen (60%) of the 30 patients were found to be symptomatic at the time of presentation with rPAVM. However, 14 had at least one other significant PAVM at the time of diagnosis of reperfusion. Only two symptomatic patients had only rPAVM, both with mild manifestations. Two patients were excluded from the study as their symptoms were attributed to other medical comorbidities. The majority of symptomatic patients with rPAVM had additional PAVMs that required embolization. Neither of the symptomatic patients with an isolated rPAVM had severe manifestations.