INTRODUCTION
The prevalence of valvular heart diseases (VHD) is estimated to be 2.5% in developed countries (1). Among VHD, aortic regurgitation (AR) is reported to be the third most common form, following mitral regurgitation (MR) and aortic stenosis (AS) (2). The prevalence of VHD increases especially in patients over 65 years of age because of the predominance of degenerative etiologies (1). Several surveys have been performed to clarify the etiologies of AR so far. Roberts et al. examined 268 patients who had isolated aortic valve (AV) replacement (AVR) for pure AR and concluded that the causes of AR were diverse and the most common category was “cause unclear” in their study (3). In the Euro Heart Survey on VHD, degenerative tricuspid and bicuspid AR were the most common etiologies, accounting for approximately two-thirds of the underlying etiology of AR in the Euro Heart Survey on VHD (4) (5).
In detail, degenerative origin of AR accounted for approximately half (50.3%) and rheumatic AR was present in 15.2%. In addition, Braun et al. reported that RA and other connective tissue diseases can cause valvular disease including AR (6). While AVR has been an established surgical definitive therapy for the treatment of AR, aortic valvuloplasty (AVP) has also been acknowledged gradually as another surgical option for AR (7). Although AVP is not so prevailed as mitral valvuloplasty, both plasty procedures have more advantages such as freedom from anticoagulant therapy. It is essential to conduct precise anatomical assessment preoperatively for a successful valvuloplasty and for the prevention of recurrence of significant regurgitation (8). Recent advancement in echocardiography enables to detect more detailed abnormal morphology of aortic cusps accurately. Cusp bending of aortic valve has been detected more commonly with AR on transesophageal echocardiography (TEE) examination, which is observed as a fibrous band on a cusp (Figure 1, 2, 3, 4) (9) (10) (11). Nevertheless, the prevalence of cusp bending and its clinical characteristics remain to be clarified in pure AR patients. Therefore, the aim of this study was to thoroughly examine the etiologies of AR through observing aortic valve morphology by use of TEE images.