Introduction
Several studies have focused on the anatomy and pathophysiology of secondary tricuspid regurgitation (TR) associated with left heart disease or atrial fibrillation (1,2). Patients with significant TR, especially that in the severe range, have a poor prognosis (3,4). Surgical treatment can produce excellent results in patients with severe TR that medical treatment is unable to control (4,5). However, patients requiring reoperation because of significant residual or recurrent TR have a poor prognosis with high mortality (6). Therefore, it is very important to address TR during the operation and analyze the risk factors for residual TR after tricuspid valve (TV) repair (7-9).
Sakon et al. (10) recently demonstrated that the number of posterior leaflets was two or more in a half of the patients analyzed in their study. However, no studies have shown that morphological diversity of the TV affects the outcomes and surgical techniques of TV repair. The present study was performed to investigate the effect of morphological diversity of the TV on the difficulty of controlling TR during TV repair.