Occlusion Of Pulmonary Arteriovenous Malformations Research Articles

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.

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.

Early Experience with the AMPLATZER Vascular Plug IV for the Occlusion of Pulmonary Arteriovenous Malformations

The recent generation of AMPLATZER Vascular Plug (AVP; ie, the AVP IV) was used for the occlusion of eight pulmonary arteriovenous malformations (PAVMs) in five patients. A treatment was considered successful when there was a reduction or disappearance of the aneurysmal sac. At a mean follow-up of 20.1 months, no recanalization of PAVMs was observed on multidetector computed tomographic angiography. This shows the AVP IV to be safe and effective as an embolic device to occlude PAVMs.

Occlusion of Pulmonary Arteriovenous Malformations Using the Amplatzer Vascular Plug/Duct Occluder for a Family With Hereditary Hemorrhagic Telangiectasia

An 8-year-old girl was referred because of frequent epistaxis and acrocyanosis. The family history showed that her father, aunt, uncle, and grandfather also experienced recurrent epistaxis. Based on her clinical information, we diagnosed her condition as hereditary hemorrhagic telangiectasia, also known as Rendu-Osler-Weber disease, which is characterized by multiple telangiectases, recurrent epistaxis, arteriovenous malformation, and familial inheritance. Chest radiography and computed tomography (CT) showed two large pulmonary arteriovenous fistulas (PAVFs) in the posterobasal and mediobasal segment of the left lower lung (Fig. 1). Percutaneous transcatheter embolization then was planned. After right heart catheterization and pulmonary angiography had been performed, we confirmed a large PAVF (diameter, 8.2 mm) in the posterobasal part of left lung, with a smaller lesion (diameter, 2.9 mm) in the pulmonary artery of the left middle lobe. A 10 9 12-mm Amplatzer duct occluder (AGA Medical Corporation, Golden Valley, MN, USA) was selected for the larger PAVF, and a Gianturco coil (4 9 3 mm; Cook Inc., Bloomington, IN, USA) was chosen for the smaller feeding artery (Fig. 1). After a successful procedure, percutaneous oxygen saturation at rest rose to more than 95% with room air compared with about 71% before the procedure. Recently, the girl’s father also was evaluated for mucocutaneous telangiectases on his tongue and in his nasal mucosa. Chest radiography and multidetector CT again showed bilateral multiple PAVFs. A cardiac catheterization with pulmonary angiography showed four large PAVFs of the right upper (feeding vessels of 2.8 mm), right lower (3.5 mm), left upper (3.2 mm), and left lower (4.2 mm) lung. Considering their large sizes, we decided to perform percutaneous closure using Amplatzer vascular plugs for all four PAVFs. Devices 30–50% larger than the selected vessel diameter were chosen: 4 9 7 mm for the right upper lesion, 6 9 7 mm for the right lower and left upper lesion, and 8 9 7 mm for the left lower lesion. Angiograms obtained at the end of each procedure confirmed good positioning of the devices with no significant residual flow (Fig. 2). About 20–30% of patients with hereditary hemorrhagic telangiectasia are thought to be affected with PAVFs [4]. Various methods for transcatheter embolization have been reported, including coils and detachable balloons. Although transcatheter embolization with coils is considered the preferred method for PAVFs, it is not ideal for large fistulas with large feeding arteries due to disadvantages such as the risk for paradoxical device embolization, the need for multiple coils, and the high recanalization rates [1–3]. The Amplatzer vascular plug/duct occluder has been reported as a new alternative for the occlusion of PAVFs. An additional advantage of the Amplatzer vascular plug is the relatively smaller introduction system than that used for the Amplatzer duct occluder. Although most reported cases involve adult patients, the reported familial case including an 8-year-old girl demonstrates that the Amplatzer vascular plug and duct occluder also provide excellent results for young patients with multiple large PAVFs. M. J. Cho Department of Pediatrics, Pusan National University Hospital, Ami-dong, Seo-gu, Busan 602-739, Republic of Korea

Reperfusion of Pulmonary Arteriovenous Malformations after Successful Embolotherapy with Vascular Plugs

Amplatzer vascular plugs (AVPs) are among the embolic agents currently used for occlusion of pulmonary arteriovenous malformations (PAVMs). The authors encountered a patient with multiple PAVMs who developed spontaneous reperfusion of two PAVMs within 7 weeks of initially successful embolization with AVPs. Reperfused PAVMs were effectively occluded by coils deposited proximal to the vascular plugs. AVPs do not provide consistent long-term occlusion of the PAVMs. Deposition of coils proximal to the AVP may decrease the chance of PAVM reperfusion after the embolization.

Occlusion of pulmonary arteriovenous malformations by use of vascular plug

Pulmonary arteriovenous malformations are commonly treated by embolization with coils or balloons to prevent cerebral complications and to raise the oxygenation of the blood. The Amplatzer vascular plug is a new occlusive device made of a self-expanding cylindrical nitinol mesh. It is fast and safe to position, and can be repositioned before final delivery. It is especially suited for embolization of large high-flow vessels as in pulmonary arteriovenous malformations with big feeding arteries. Two cases of successful use of the new device for treatment of large pulmonary arteriovenous malformations are described.