The Forgotten Functional Triscupid Insufficiency: Is Valve Repair Necessary?

Despite a half-century of experience in heart valve reconstruction, the tricuspid valve has been a "second class structure" for cardiac surgery. More than 20 years ago, the high incidence of tricuspid disease in our population, encouraged us to attempt to clarify the indications for repair, particularly in patients with functional tricuspid incompetence (1). Since functional tricuspid insufficiency always reflects some degree of right ventricular failure with elevated pulmonary resistance, or significant volume overload, we concluded that mild and moderate tricuspid incompetence can be surgically ignored only when the pulmonary resistance will predictably be reduced. However, the experience has demonstrated this beneficial postoperative event is not always well-anticipated. On the other hand, some patients with postoperative low pulmonary vascular resistance continue with functional tricuspid insufficiency because they do not recover the ability of the tricuspid valve annulus to shorten in systole.

Nowadays, with more than 900 functional tricuspid valves repaired at our Institution, it is time to analyse the state of the art of this commonly forgotten valve pathology. Current articles and meeting presentations on the functional tricuspid valve insufficiency are scarce and still asking the same type of questions: Should it be repaired? (2), What should be done? (3).

Functional tricuspid regurgitation is not a rare entity, since more than 25% of mitral valve insufficiency is associated with some degree of tricuspid dilatation with normal valve structures. This entity is often unrecognised, being only apparent during periods of increased preload or afterload. Dilatation of the annulus, involving the annular area supporting the anterior and posterior leaflets, is the only pathological finding at surgery. It is not always clear whether a functional tricuspid insufficiency, which might be expected to disappear or to improve, will remain and progressively increase the right ventricular cardiomyopathy, pulmonary hypertension, and chronic systemic venous hypertension, contributing to a poor outcome. One-third of symptomatic patients with an ignored functional tricuspid valve insufficiency at the time of left-sided valve surgery are referred later for isolated tricuspid valve operation.

A better understanding of the natural history of functional tricuspid incompetence and the progress made in transesophageal echocardiography have contributed significantly to the clarification of the indications and the limits for tricuspid valve repair. However, preoperative echo based on tricuspid valve grading at rest does not compare well with tricuspid dilatation found at surgery. Under general anesthesia, intraoperative echocardiography is not very useful in quantifying the tricuspid regurgitation in order to indicate valve repair or to assure valve competence after correction.

Different methods and rules are used to indicate valve repair in the presence of functional tricuspid insufficiency. The indications are based on the clinical, echocardiography, and surgical findings. Moderate and severe tricuspid regurgitation should be repaired, since it has been widely demonstrated that in those patients, tricuspid annuloplasty provides better symptomatic results and may improve survival. Further, the need for reoperation for isolated tricuspid valve repair after prior left heart valve surgery is also avoided. Dreyfus et al (2) recommend examining the valve at the time of mitral valve surgery and repairing the tricuspid annulus if it is dilated to more than twice normal (greater than 70 mm between the antero-septal and postero-septal commissures). Colombo et al. (4), when treating tricuspid insufficiency surgically when the indexed annulus dimension was more than 21 mm/m², found this effective in term of clinical improvement and of late functional results.

Double venous cannulation is used in patients with mitral valve disease, and we always open the right atrium to inspect the tricuspid valve when pre- or per-operative echocardiography demonstrate a significant (moderate or severe) tricuspid regurgitation, in the presence of right atrial or ventricular dilatation, and in cases of high pulmonary artery systolic pressure.

Thirty years ago after the De Vega annuloplasty was described (5), this simple selective remodeling of the tricuspid annulus with a double suture at the anterior and posterior area continues as the most popular reconstructive surgical technique for significant functional tricuspid insufficiency. We have used a modified De Vega annuloplasty using interrupted pledget-supported sutures. This segmental tricuspid annuloplasty (6) avoids tearing of the suture from the tricuspid annulus, "guitar string valve incompetence", which leads to failure of De Vega annuloplasty early after surgery.

In our experience, multivariate analysis in a recent group 230 patients with functional tricuspid insufficiency demonstrates that the independent risk factors for tricuspid valve reoperation were the presence of residual tricuspid valve incompetence (OR: 3.25), pulmonary artery systolic pressure > 55 mmHg (OR: 2.5) or ignored functional tricuspid insufficiency.

In patients with severely dilated tricuspid annulus, we prefer a flexible ring annuloplasty, which prevents repair failure, allows physiological dynamic changes in the annular size and shape, and prevents future enlargement of the annulus. The controversy of whether a rigid or a flexible annuloplasty ring is better for tricuspid valve annuloplasty is still unsettled. The criticism that a deformable (flexible) ring does not restore the physiological shape of the annulus and thus requires overcorrection, resulting in a high incidence of residual tricuspid stenosis, was not true in our experience.

Modern cardiac reconstructive surgery should pay more attention to this frequently forgotten valve pathology, which is killing many of our patients.

References

1. Duran CMG, Pomar JL, Colman T, Figueroa A, Revuelta JM, Ubago JL. Is tricuspid valve repair necessary?. J Thorac Cardiovasc Surg 1980;80:849-860.
2. Dreyfus GD, Bahrami T, Chan KMJ, Aazami H, Mihealainu S. Secondary tricuspid dilatation with or without regurgitation: Should it be repaired?. 16th Annual Meeting of the EACTS. Monaco. Abstract n.069O. Abstract book pg 216. 2002.
3. von Segesser LK, Stauffer JC, Delabays A, Chassot PG. Tricuspid valve insufficiency: what should be done?. Ther Umsch 1998;55(12):767-672.
4. Colombo T, Russo C, Ciliberto GR, Lanfranconi M, Bruschi G, Agati S, Vitali E. Tricuspid regurgitation secondary to mitral valve disease: tricuspid annulus function as guide to tricuspid valve repair. Cardiovasc Surg 2001;9:369-377.
5. De Vega NG. La anuloplastia selectiva, regulable y permanente. Rev Esp Cardiol 1972;25:555-560.
6. Revuelta JM, Garcia-Rinaldi R. Segmental tricuspid annuloplasty: a new technique. J Thorac Cardiovasc Surg 1989;97:799-801.