**1. Introduction**

In the past, the TV has received less attention than the other heart valves in terms of pathophysiology and surgical treatment. TV is part of a complex functional structure that involves the right atrium (RA), the right ventricle (RV), and the pulmonary artery (PA) circulation. The prevalence of TV disease is steadily increasing, with the tricuspid regurgitation (TR), the most common form, occurring in an estimated 65–85% of the European population [1]. The most common type of TV disease is functional tricuspid regurgitation (FTR), occurring secondary to the dilation of the tricuspid annulus and/or the tethering of the valve leaflets due to RV dilation and dysfunction. However, with the recent increase in right-sided implantation of transvenous devices (pacemakers, implantable defibrillators), there has been a parallel increase in the risk of organic tricuspid disease. Recent data suggests that TR is not benign, and many patients would benefit from intervention during left-sided valve surgery or in the early period of isolated TV disease (TVD) [2]. The clinical evaluation of TVD is often difficult because of a lack of early clinical characteristics, as the disease might progress when it is diagnosed by a consultant. In order to manage symptoms, prevent complications, and improve quality of life, advanced TVD has to be surgically repaired or replaced [3].

Isolated TR patients are rarely referred for valve surgery and most repairs are performed at the same time with other planned cardiac procedures. With an in-hospital mortality rate up to 37% re-operations for evident TR and heart valve disease or for recurrent TR, generally they are not routinely recommended for most patients [2]. The current American and European guidelines advocate a more proactive approach for the treatment of TR and/or annular dilatation during left-sided valve surgery. For its better superior long-term outcomes, tricuspid annuloplasty is the preferred technique. This renewed interest in surgical repair has been fueled by the development of a new generation of tricuspid annuloplasty rings and the technological advances in transcatheter treatment, which has expanded to include tricuspid pathologies in otherwise inoperable patients with advanced tricuspid disease and cardiomyopathy. Aggressive approach to surgical treatment is more widely adopted, rather than prophylactic interventions. Still, aggressive tricuspid surgery remains an area of controversy, while surgical repair is considered the gold standard for functional TR [4]. An important note is that presumably because of right ventricle anatomy the pathophysiology of functional TR is understood much less than functional mitral regurgitation (MR). Besides, the left ventricle function has a key role for the function of the right ventricle [5].
