A new technique for tricuspid valve repair addressing the subvalvular apparatus in functional tricuspid regurgitation

Abstract

Annular dilatation is the main mechanism for tricuspid regurgitation, but right ventricular dilatation often adds a restrictive mechanism, which may limit durability. We describe a subvalvular technique anchoring the chordal origins to the annuloplasty, with the aim to stabilize valve geometry and increase durability. A Goretex suture is attached to the anterior papillary muscle. One arm of the suture is stitched through the septal muscle and both arms are atrialized underneath the septal leaflet and tied to the annuloplasty band. In 12 patients (75 ± 6 years, EuroSCORE II 10 ± 9%), severe-torrential tricuspid regurgitation was successfully reduced to mild. Results were stable in all but one patient during follow-up (1–15 months). NYHA class and general health status was improved. This subvalvular technique is safe with the potential to generate a durable repair.

The main mechanism of tricuspid regurgitation (TR) is tricuspid annular dilatation [1, 2] and treatment generally consists of annuloplasty.

INTRODUCTION

The main mechanism of tricuspid regurgitation (TR) is tricuspid annular dilatation [1, 2] and treatment generally consists of annuloplasty. However, additional right ventricular dilatation causing leaflet restriction may limit the repair success [1, 2]. A similar pathophysiology is associated with long-term failures of mitral valve annuloplasty. Subvalvular techniques, generally anchoring the papillary muscles to the annulus, have been developed with encouraging initial follow-up results [3, 4].

We established a subvalvular technique for the tricuspid valve. While the mitral valve has 2 distinct papillary muscles, tricuspid valves show a wide variety of their subvalvular apparatus. In theory, chordae come off 3 papillary muscles. In practice, a large anterior papillary muscle originates from the free right ventricular wall and inferior and septal papillary muscles may or may not be fully expressed and chordae may originate from the septum or the ventricular wall directly [5].

SURGICAL TECHNIQUE

Figure 1 schematically shows the principle mechanism of action of the subvalvular technique. It also illustrates the theoretical offspring and insertion of tricuspid valve chords. However, in practice, there is a high rate of variability so that the technique has to be adapted to the individual anatomic situation. Video 1 shows a head camera recording with annotated guidance through the key parts of the procedure in a patient with torrential TR. A felt-pledgeted 4–0 Goretex suture is attached to the largest imposing (mostly anterior) papillary muscle. One arm of the suture is stitched through the inferior papillary (if present) and one arm is stitched through the septal muscle. Both suture arms are then atrialized underneath the septal leaflet and tied to the annuloplasty band. The suture is tied after the water test has demonstrated valve competence to secure the current geometric position, thereby preventing future restriction from ventricular dilatation. In theory, the suture is not primarily required for achieving repair success, but to stabilize the geometry and prevent future failure. Thus, the suture only requires minor tension (so the ends are not lost) for tying.

Figure 1:

Schematic illustration of the theoretical offspring and insertion of tricuspid valve chords and the principle mechanism of action of the subvalvular technique. In practice, there is a high rate of variability so that the technique has to be adapted to the individual anatomic situation (modified from Wang et al. [5]).

PATIENTS

We performed 12 tricuspid valve repairs on the beating heart (8 with minimally invasive access). Patients were 75 ± 5.9 years old (EuroSCORE II 10 ± 9.1%). Isolated tricuspid valve surgery was performed in 7 patients and additional surgery (mitral valve surgery and/or bypass grafting) was needed in 5. Ethics waived the need for informed consent. Mean follow-up was 6 months (1–15 months). One patient died postoperatively in acute respiratory distress syndrome.

Table 1 shows the key echocardiographic parameters. Preoperatively, patients had severe (66%) or torrential TR (33%). Surgery eliminated TR in one, reduced it to mild in 6 and to mild-moderate in 4 patients. Only one patient presented with worsening of TR during follow-up (from mild to moderate to moderate to severe). Reduction in TR caused a decrease in right ventricular diameter and clinically signs and symptoms of volume overload regressed, allowing a subsequent reduction of diuretics. NYHA class improved from 2.9 ± 0.3 to 1.6 ± 0.9 and health-related quality of life (EQ-5D) postoperatively was 73 ± 20, which is above the age-matched German average (60).

Table 1:

Echocardiographic determination of tricuspid regurgitation

	Preoperative (N = 12)	Postoperative (N = 12)	Follow-up (N = 11)
None	0	1 (8.4%)	2 (18.2%)
Mild	0	7 (58.3%)	6 (54.5%)
Mild-moderate	0	4 (33.3%)	2 (18.2%)
Moderate-severe	0	0	1 (9.1%)
Severe	8 (66.7%)	0	0
Torrential	4 (33.3%)	0	0
RVDd (mm)	43.80 ± 15.32	38.33 ± 12.01	34.67 ± 7.42

Vaules are n (%) or mean ± standard deviation. Follow-up was a median of 6 months (1–15 months).

RVDd: right ventricular dimension in diastole.

DISCUSSION

This new subvalvular technique for severe cases of TR is safe and may generate a durable repair.

Subvalular techniques have been described for the mitral valve achieving promising results [3, 5] including a potential impact on prognosis [4]. To our knowledge, no such technique has thus far been described for the tricuspid valve, but the restrictive mechanism stemming from papillary dispositioning caused by ventricular dilatation is generally the same. However, the above described differences in anatomy [5] pose a challenge. Our technique therefore focuses on securing a Goretex suture to the largest present papillary muscle (generally the anterior muscle), and level guide one arm of the suture with possibly additionally available papillary muscles (often the posterior one) and one arm with the septum itself. The resulting ‘subvalvular triangle’ should result in the geometric fixation of the chordal origins. This fixation is to stabilize the geometry and is therefore not necessarily required to achieve intraoperative success. However, it hopefully secures valve function in the future even if the ventricle further dilates. Our initial experience is promising, but longer-term follow-up and a comparison of this technique to one with classic annuloplasty alone are needed to fully assess the therapeutic potential.

Conflict of interest: none declared.

Reviewer information

Interactive CardioVascular and Thoracic Surgery thanks Stefano Mastrobuoni and the other anonymous reviewer(s) for their contribution to the peer review process of this article.

 

Presented at the 34th Annual Meeting of the European Association for Cardio-Thoracic Surgery, Barcelona, Spain, 8–10 October 2020.