当前位置: 首页 > 期刊 > 《血管的通路杂志》 > 2005年第6期 > 正文
编号:11354303
Pseudoaneurysm of the mitral-aortic intervalvular fibrosa following aortic valve replacement – diagnosis and dynamic evaluation with multide
http://www.100md.com 《血管的通路杂志》
     a Department of Radiology, Rambam Medical Center, B. Rappaport-Faculty of Medicine, Technion-Israel Institute of Technology, P.O. Box 9602, Haifa 31096, Israel

    b Department of Cardiology, Rambam Medical Center, B. Rappaport-Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel

    c Department of Cardiac Surgery, Rambam Medical Center, B. Rappaport-Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel

    Abstract

    Sixteen-slice multidetector CT findings of a pulsatile pseudoaneurysm of the mitral-aortic intervalvular fibrosa, in a woman following aortic valve replacement, are presented. Multidetector CT depicted the pseudoaneurysm and enabled dynamic evaluation of its lumen through the cardiac cycle, documenting expansion during systole and almost complete collapse during diastole. This case illustrates the capabilities of multidetector cardiac CT in the evaluation of aortic valve pathology.

    Key Words: Multidetector CT; Echocardiography; Pseudoaneurysm; Mitral-aortic intervalvular fibrosa; Aortic valve; Aortic valve replacement

    1. Case report

    A 61-year-old woman was admitted with a four-month history of recurrent fever accompanied by chills and myalgias. Nine months earlier she had her aortic valve replaced using a bileaflet mechanical prosthesis, due to severe bicuspid aortic stenosis. Based on her history and clinical manifestations prosthetic valve infective endocarditis was postulated. Transesophageal echocardiography (TEE) and ECG gated cardiac multidetector CT (MDCT) were obtained. ECG gated MDCT was performed during a 25-s breath hold at full inspiration, using a BrillianceTM 16-slice scanner (Philips Medical Systems, Cleveland, Ohio, USA). The post-processing reformations were performed on a Brilliance Extended WorkspaceTM workstation (Philips Medical Systems, Cleveland, Ohio, USA). MDCT evaluation of the prosthetic valve through the cardiac cycle (Fig. 1A and B), documented a 16-mm pulsatile pseudoaneurysm of the mitral-aortic intervalvular fibrosa (PMAIF) (solid black arrows), below the aortic valve annulus. Dynamic evaluation documented volume expansion during systole followed by almost complete collapse during diastole. The pseudoaneurysm lumen filled with contrast material from the left ventricle outflow tract through a 6-mm fistulous dehiscence of the suture line. Both prosthetic valve leaflets showed normal symmetric opening (Video 1). Coronary CT angiography demonstrated normal coronary arterial anatomy. TEE confirmed the aforementioned findings (Fig. 2A–D), as well as documenting turbulent flow in the pseudoaneurysm lumen. TEE additionally identified a 10-mm mobile vegetation at the pseudoaneurysm neck attached to the posterior aspect of the prosthetic valve ring (Fig. 2E). This vegetation was not depicted on MDCT even following retrospective analysis. The combined imaging findings of both modalities and positive blood cultures established the diagnosis of prosthetic valve infective endocarditis. Appropriate systemic antibiotic treatment resulted in complete clinical recovery. During a follow-up period of 10 months using serial TEEs, the patient remained asymptomatic, the PMAIF remained stable in size and a continuous contraction of the prosthetic valve vegetation was noted.

    Video 1. Dynamic evaluation of the mitral-aortic intervalvular fibrosa pseudoaneurysm, prosthetic aortic valve and left ventricular outflow tract using MDCT. Note the pulsatile pseudoaneurysm lumen () and the normal symmetric opening of both prosthetic valve leaflets (arrows).

    2. Discussion

    PMAIFs are uncommon but potentially catastrophic complications of aortic valve surgery, aortic valve endocarditis or chest trauma [1]. These pseudoaneurysms, especially when large, may rupture into the left atrium or aorta, cause systolic compression of proximal coronary arterial segments, lead to systolic compression of the mitral valve with severe regurgitation and may even erode the chest wall [1–4]. PMAIFs are commonly diagnosed by transesophageal echocardiography and transthoracic echocardiography with a reported sensitivity of 90% and 43%, respectively [2,5,6]. The main imaging finding on TEE is the demonstration of a false lumen below the aortic valve annulus, at the mitral-aortic intervalvular fibrosa, which expands during systole and collapses during diastole. Color Doppler usually demonstrates an internal turbulent flow pattern. MRI has also been described as enabling detailed imaging of a PMAIF [1,7]. To the best of our knowledge, this case report documents for the first time the application of ECG gated MDCT in the diagnosis and dynamic evaluation of PMAIF in a patient following aortic valve replacement. Although ECG gated 16-slice cardiac MDCT at present, is associated with an effective radiation dose exposure of 8.1–10.9 mSv [8], it can provide accurate non-invasive diagnosis of pseudoaneurysms, including their location, size and pulsatility. Furthermore, accurate evaluation of prosthetic valve leaflets motion and coronary arteries is feasible as well.

    This case illustrates the full capabilities of MDCT technology at present, in the non-invasive evaluation of patients following aortic valve replacement. The technique provides not only high-resolution 3-D anatomical detail, but also dynamic evaluation through the cardiac cycle.

    References

    Espinosa-Caliani JS, Montijano A, Melero JM, Montiel A. Pseudoaneurysm in the mitral-aortic intervalvular fibrosa. A cause of mitral regurgitation. Eur J Cardiothorac Surg 2000;17:757–759.

    Afridi I, Apostolidou MA, Saad RM, Zoghbi WA. Pseudoaneurysms of the mitral-aortic intervalvular fibrosa: dynamic characterization using transesophageal echocardiographic and Doppler techniques. J Am Coll Cardiol 1995;25:137–145.

    Agirbasli M, Fadel BM. Pseudoaneurysm of the mitral-aortic intervalvular fibrosa: a long-term complication of infective endocarditis. Echocardiography 1999;16:253–257.

    Parashara DK, Jacobs LE, Kotler MN, Yazdanfar S, Spielman SR, Janzer SF, Bemis CE. Angina caused by systolic compression of the left coronary artery as a result of pseudoaneurysm of the mitral-aortic intervalvular fibrosa. Am Heart J 1995;129:417–421.

    Aoyagi S, Fukunaga S, Otsuka H, Akaiwa K, Yokokura Y, Yokokura H. Left ventricular outflow tract pseudoaneurysm after aortic valve replacement: case report. J Heart Valve Dis 2004;13:145–148.

    Pongratz G, Pohlmann M, Gehling G, Bachmann K. Images in cardiovascular medicine. Pseudoaneurysm in the intervalvular mitral-aortic region after endocarditis and prosthetic aortic valve replacement. Circulation 1997;96:3241–3242.

    Yokoyama Y, Tamaki S, Kato N, Yokote J, Mutsuga M. Pseudoaneurysm from the mitral-aortic intervalvular fibrosa following endocarditis. Jpn J Thorac Cardiovasc Surg 2003;51:374–377.

    Trabold T, Buchgeister M, Kuttner A, Heuschmid M, Kopp AF, Schroder S, Claussen CD. Estimation of radiation exposure in 16-detector row computed tomography of the heart with retrospective ECG-gating. Rofo 2003;175:1051–1055.(Eduard Ghersin, Diana Lit)