Percutaneous Transthoracic Treatment of Ascending Aortic and Root Pseudoaneurysms: Procedural Aspects and Guidance with the Use of Multimodality Imaging

Open repair of ascending aortic pseudoaneurysms (AAPs) is currently the standard of care, but it is associated with high morbidity and mortality. A single-center retrospective experience of 4 patients after cardiac surgery undergoing 5 percutaneous transthoracic embo lization procedures is presented. In 3 of the 4 patients, the primary outcome of complete thrombosis was achieved after the first pro cedure, with a mean follow-up time of 11.5 months. In all 5 procedures, the patients tolerated the procedure well without associated acute complications. Percutaneous transthoracic embolization of AAPs offers an alternate minimally invasive treatment pathway for prohibitive-risk candidates. ABBREVIATIONS AAP ¼ ascending aortic pseudoaneurysm, PsA ¼ posterior pseudoaneursym, TEE ¼ transesophageal echocardiography Ascending aortic pseudoaneurysms (AAPs) may arise in the setting of trauma, mycotic infections, and following cardiac surgery or aortic arch replacement (1,2). Open repair is currently the standard of care. Reoperation, however, requires repeat sternotomy and cardiopulmonary bypass, frequently in patients with multiple comorbidities. Reported mortality rates range from 7 to 41% (1,3,4). Expansion of AAPs is unpredictable and rupture can be fatal (5). There have been a few cases published regarding endovascular approaches to treating AAPs including coil embolization, endovascular stent-graft placement, and implantation of occluder devices (6,7), however not all lesions are suitable for endovascular management. We report our experience utilizing a multimodality imaging based approach for transthoracic percutaneous embolization of AAPs. MATERIALS AND METHODS This was a retrospective study with Institutional Review Board approval that waived requirement for informed consent. A total of 4 patients underwent transthoracic percutaneous embolization for AAPs from January 2015 to December 2016. The decision to intervene percutane ously was made by a multidisciplinary team consisting of interventional radiology, cardiology, and cardiothoracic surgery and was based on perceived high preoperative risk factors and suboptimal traditional transvascular access to the AAP. Imaging modalities used consisted of computerized tomography (CT), transesophageal echocardiography (TEE), and fluoroscopy for guidance. CASE REPORTS Case 1 A 55-year-old man presented with a recurrent posterior AAP after attempted reoperative repair after a Bentall procedure for a type A aortic dissection (Fig 1a, b). Preprocedural From the Vascular and Interventional Radiology (F.H., S.G., S.T.K., J.M.M.), Department of Radiology, University of California, Los Angeles, CA 90095; and Department of Cardiology (T.C., E.H.Y.), Department of Medicine, University of California, UCLA Cardiovascular Center, Los Angeles, California. Received September 28, 2017; final revision received and accepted January 5, 2018. Address correspondence to F.H.; E-mail: frankhao@mednet.ucla.edu None of the authors have identified a conflict of interest. © SIR, 2018 J Vasc Interv Radiol 2018; 29:628–631 https://doi.org/10.1016/j.jvir.2018.01.767 evaluation revealed poor transvascular access into the pseudoaneurysm due to proximity to the coronary arteries, a 1 mm neck, and perceived inability to maintain stable transvascular access in the AAP. Under CT guidance, an iatrogenic pneumothorax was performed with displacement of the lung from the projected transthoracic trajectory. An 18-gauge Chiba needle (Cook, Bloomington, Indiana) was advanced across the thoracic cavity from the right chest wall into the AAP between the right atrial appendage, aorta, and inferior vena cava under CT guidance (Fig 1c). The patient was then transported to the angiography suite with the needle stabilized in position, where TEE demon strated blood flow within the partially thrombosed pseu doaneurysm. A Renegade STC microcatheter (Boston Scientific, Marlborough, Massachusetts) was advanced through the needle under fluoroscopic and TEE guidance and the AAP was embolized to stasis with the use of a total of 0.4 cc ethylene-vinyl alcohol copolymer (EVOH; Medtronic, Irvine, California). No nontarget embolization or residual flow was noted on final aortography or TEE. Post-procedure CT angiography at 10 months’ follow-up, however, demonstrated partial recanalization. The patient was brought back and similar access was obtained with a repeated transthoracic percutaneous approach into the AAP. Coil embolization was performed with the use of Concerto microcoils (Medtronic) under fluoroscopic and TEE guid ance. CT angiography performed 5 months later showed complete thrombosis of the AAP. Case 2 A 70-year-old man developed an anterior AAP arising from the innominate arterial suture line after an endovas cular stent graft repair of an enlarging descending thoracic aortic aneurysm. The neck of the pseudoaneurysm measured 1.9 mm. An 18-gauge Chiba needle was advanced from the right parasternal space, medial to the right internal mammary artery and vein, into the retrosternal pseudoaneurysm sac under direct fluoroscopic guidance with the use of bony and sternal wires as land marks. A Renegade STC microcatheter in conjunction with a Transend microwire (Stryker Neurovascular, Kalamazoo, Michigan) was passed through the needle into the AAP. The AAP sac was then embolized with a combination of coils (Interlock; Boston Scientific) and EVOH. Post embolization aortography showed no filling of the AAP. CT performed after 8 months demonstrated complete hemostasis. Case 3 A 58-year-old woman with a history of Marfans syndrome status after aortic valve replacement, Bentall procedure, and single-vessel coronary artery bypass grafting was noted to have an enlarging 9 mm pseudoaneurysm (PsA) adjacent to the aortic sinus, with a maximal diameter of 3.2 cm on CT angiography (Fig 2a). An 18-gauge Chiba needle was advanced from the right chest wall through the right atrial appendage under CT guidance into the AAP (Fig 2b). The patient was then moved to the angiography suite, where TEE demonstrated bidirectional flow in the PsA sac and appropriate positioning of the needle (Fig 2c). With the use of bimodal fluoroscopic and echocardiographic guidance, the aneurysm sac was coil embolized to stasis (Fig 2d, e). Follow-up CT angiography and cardiac magnetic reso nance imaging after 8 months showed complete hemostasis. Case 4 A 58-year-old woman was noted to have a persistent AAP after multiple aortic valve replacements for bicuspid aortic valve, and a previous attempt at AAP closure with the use of an Amplatzer Muscular ventricular septal defect occluder (AGA Medical Corp, Plymouth, Minnesota) was unsuc cessful. Post-procedure aortography showed a residual leak seen at the inferior aspect of the AAP. The leak was seen Figure 1. (a) CT angiogram in the axial plane, demonstrating a PsA (straight arrow) arising posterior to the AR (curved arrow). Residual descending thoracic aortic dissection is present. (b) CT 3-dimensional reconstruction of the heart and vessels. Posterior and lateral view. PsA (straight arrow) arising posterior to the ascending aorta in close approximation to the left atrium (curved arrow; LA) and main pul monary artery (dotted arrow; MPA). (c) Noncontrast axial slice through the upper chest. Iatrogenic right pneumothorax (curved arrow; PTX) with a chest tube (straight arrow; CT) in place. Chiba needle (outlined arrow) traversing minimal lung due to the induced pneumothorax. Volume 29 ▪ Number 5 ▪ May ▪ 2018 629 630 ▪ Treatment of AAPs and Root Pseudoaneurysms Hao et al ▪ JVIR | Figure 2. (a) CT angiogram. Anterior (long arrow). (b) Coaxial needle artifact from cardiac motion is arrow) at 90 degrees. Color Doppler dimensional TEE, midesophageal show no evidence of residual residual flow into the PsA. TEE Table. Case Details | PsA sac (medium arrow) posterior (large arrow) traversing the RA (curved arrow) present. (c) 2-dimensional TEE, midesophageal flow through the AR shows a small short-axis view at 50 degrees of the flow between the PsA and the ascending probe is noted. | to the right atrium with the distal tip short axis view connection between aortic PsA after coiling aorta. (e) Post embolization | (short arrow; RA) and anterior to the AR in the PsA sac (outlined arrow). Motion of the aortic pseudoaneurysm (short the PsA and the ascending aorta. (d) 2- (arrows). Color Doppler is used to aortography, demonstrating no | | --- | --- | --- | --- | | Patient Age (y)/Sex Location 1 56/M Posterior 2 70/M Anterior 3 58/F Anterior 4 56/F Anterior | Diameter (cm) Immediate Success (Aortography/TEE) 4.7 Achieved 3.5 Achieved 3.2 Achieved 4.7 Achieved | Procedural Complications None None None None | Follow-Up (mo) Recurrence 8 Yes 8 No 13 No 17 No | TEE ¼ transesophageal echocardiography. The other patient achieved complete thrombosis after a second percutaneous treatment. In all 5 procedures, the patients tolerated the procedure wel